JP4989984B2 - Optical film and method for producing the same, polarizing plate using the optical film, and liquid crystal display device - Google Patents

Description

  The present invention relates to an optical film, a manufacturing method thereof, a polarizing plate using the optical film, and a liquid crystal display device. In particular, the present invention relates to an optical film, a polarizing plate, and a liquid crystal display device that realize high-quality visibility with little viewing angle dependency.

The liquid crystal display device is increasingly used year by year as an image display device with small power consumption and a small space. Conventionally, large viewing angle dependence of images has been a major drawback of liquid crystal display devices, but in recent years, various high viewing angle modes with different alignment states of liquid crystal molecules in liquid crystal cells have been put into practical use. As a result, demand for liquid crystal display devices is rapidly expanding even in markets where a high viewing angle is required, such as televisions.
In general, a liquid crystal display device includes a liquid crystal cell, an optical compensation sheet, and a polarizer. The optical compensation sheet is used for eliminating image coloring or expanding the viewing angle, and a stretched birefringent film or a film obtained by applying a liquid crystal to a transparent film is used. For example, Patent Document 1 discloses a technique for applying an optical compensation sheet in which a discotic liquid crystal is applied on a triacetyl cellulose film, aligned, and fixed to a TN mode liquid crystal cell to widen the viewing angle. However, a television-use liquid crystal display device that is expected to be viewed from various angles on a large screen has a strict requirement for viewing angle dependency, and even with the above-described method, the requirement cannot be satisfied. Therefore, liquid crystal display devices different from the TN mode, such as an IPS (In-Plane Switching) mode, an OCB (Optically Compensatory Bend) mode, and a VA (Vertically Aligned) mode, have been studied.

In particular, the VA mode is attracting attention as a liquid crystal display device for TV because of its high contrast and relatively high manufacturing yield. However, in the VA mode, almost complete black display is possible in the normal direction of the panel, but when the panel is observed from an oblique direction, light leakage occurs and the viewing angle becomes narrow. To solve this problem, a first retardation plate having a positive refractive index anisotropy satisfying nx> ny = nz and a second phase having a negative refractive index anisotropy satisfying nx = ny> nz A method of reducing light leakage by using a phase difference plate in combination has been proposed (for example, Patent Document 1). Further, it has been proposed to improve the viewing angle characteristics of a VA mode liquid crystal display device by using an optically biaxial retardation plate of nx>ny> nz (for example, Patent Document 2). Here, nx, ny, and nz respectively indicate refractive indexes in the X-axis direction, the Y-axis direction, and the Z-axis direction in the retardation plate. The X-axis direction is an axial direction showing the maximum refractive index in the in-plane direction of the retardation plate, and the Y-axis direction is an axial direction perpendicular to the X-axis direction in the plane, The Z-axis direction indicates a thickness direction perpendicular to the X-axis direction and the Y-axis direction.
On the other hand, each liquid crystal system including the IPS system and the OCB system has improved the display system with the recent increase in demand for liquid crystal televisions.
However, these methods only reduce light leakage for a certain wavelength range (for example, green light near 550 nm), and other wavelength ranges (for example, blue light near 450 nm, red light near 650 nm). The light leakage is not considered. For this reason, for example, when black is displayed and observed from an oblique direction, the so-called color shift problem of coloring blue or red has not been solved.

  Further, although a single birefringent film has a smaller wavelength difference (ie, has reverse dispersion), a copolymer or blend polymer composed of special monomer units is disclosed (for example, Patent Document 3). ), A birefringent film having a phase difference and reverse dispersion with a low molecular weight compound has insufficient retardation characteristics.

  Therefore, a method for optimizing retardation for blue light, green light, and red light of an optical compensation film has been demanded as means for improving the viewing angle contrast and light leakage of black display.

Japanese Patent No. 3027805 Japanese Patent No. 3330574 JP 2002-156528 A

  An object of the present invention is to provide an optical film capable of high display quality in which black display does not cause coloring even when observed obliquely, a polarizing plate using the same, and a liquid crystal display device.

（一般式（Ｉ）中、Ｌ _１ およびＬ _２ は、それぞれ、単結合または二価の連結基を表す。Ａ _１ およびＡ _２ は−Ｏ−、−ＮＲ−（Ｒは水素原子または置換基）、−Ｓ−、−ＣＯ−からそれぞれ独立に選ばれる基である。Ｒ _２ 及びＲ _３ は、それぞれ、置換基として４−アルキルシクロヘキシル基を４位に有するシクロヘキサン環を表し、Ｒ _１ 、Ｒ _４ およびＲ _５ は置換基を表す。ｎは０から２までの整数を表す。）
＜２＞
下記一般式一般式（ＩＩ）、（ＩＩＩ）、（ＩＶ）、又は（Ｖ）で表される化合物から選ばれる少なくとも一種を含有することを特徴とする＜１＞に記載の光学フイルム。
一般式（ＩＩ）

（一般式（ＩＩ）中、Ｒ ^１２ は、各々独立に、オルト位、メタ位およびパラ位の少なくともいずれかに置換基を有する芳香族環または複素環を表す。Ｘ ^１１ は、各々独立に、単結合または−ＮＲ ^１３ −を表す。ここで、Ｒ ^１３ は、各々独立に、水素原子、置換もしくは無置換のアルキル基、アルケニル基、アリール基または複素環基を表す。）
一般式（ＩＩＩ）

（一般式（ＩＩＩ）中、Ｒ ⁴ 、Ｒ ⁵ 、Ｒ ⁶ 、Ｒ ⁷ 、Ｒ ⁸ 及びＲ ⁹ は各々独立して、水素原子又は置換基を表す。）
一般式（ＩＶ）
Ｑ ⁷¹ −Ｑ ⁷² −ＯＨ
（一般式（ＩＶ）中、Ｑ ⁷¹ は含窒素芳香族ヘテロ環、Ｑ ⁷² は芳香族環を表す。）
一般式（Ｖ）：

（一般式（Ｖ）中、Ｑ ⁸¹ 及びＱ ⁸² はそれぞれ独立に芳香族環を表す。Ｘ ⁸¹ はＮＲ ⁸¹ （Ｒ ⁸¹ は水素原子又は置換基を表す）、酸素原子又は硫黄原子を表す。）
＜３＞
前記の低分子化合物及びＲｔｈ上昇剤の少なくとも一方が１００℃〜３００℃の温度範囲で液晶相を示すことを特徴とする＜１＞又は＜２＞に記載の光学フイルム。
＜４＞
下記式（１）〜（３）を満たすことを特徴とする＜１＞〜＜３＞のいずれか１項に記載の光学フィルム。
式（１） Ｒｅ（５５０）＞２０ｎｍ
式（２） ０．５＜Ｎｚ＜１０
式（３） −２．５×Ｒｅ（５５０）＋３００＜Ｒｔｈ（５５０）＜−２．５×Ｒｅ（５５０）＋５００
（式中、Ｒｅ（λ）及びＲｔｈ(λ)はそれぞれ、波長λｎｍの光を入射させて測定した面内及び面外レターデーション（単位：ｎ）であり、Ｎｚ=Ｒｔｈ（５５０）／Ｒｅ（５５０）＋０．５とする。）
＜５＞
下記式（Ａ）〜（Ｄ）を満たすことを特徴とする＜１＞〜＜３＞のいずれか１項に記載の光学フイルム。
（Ａ）０．１＜Ｒｅ（４５０）／Ｒｅ（５５０）＜０．９５
（Ｂ）１．０３＜Ｒｅ（６５０）／Ｒｅ（５５０）＜１．９３
（Ｃ）０．４＜（Ｒｅ／Ｒｔｈ（４５０））／（Ｒｅ／Ｒｔｈ（５５０））＜０．９５
（Ｄ）１．０５＜（Ｒｅ／Ｒｔｈ（６５０））／（Ｒｅ／Ｒｔｈ（５５０））＜１．９
（式中、Ｒｅ（λ）は、波長λｎｍの光に対する該フィルムの面内レターデーション値であり、Ｒｔｈ（λ）は、波長λｎｍの光に対する該フィルムの厚み方向のレターデーション値であり、Ｒｅ／Ｒｔｈ（λ）は、波長λｎｍの光に対する該フィルムの面内レターデーション値と厚み方向のレターデーション値の比である（単位：ｎｍ）。）
＜６＞
フイルムを延伸する延伸工程と収縮させる収縮工程とを含む製造方法によって製造されたことを特徴とする＜１＞〜＜５＞のいずれか１項に記載の光学フイルム。
＜７＞
光学フイルムがセルロースアシレートからなることを特徴とする＜１＞〜＜６＞のいずれか１項に記載の光学フイルム。
＜８＞
セルロースアシレートのアシル置換基が実質的にアセチル基のみからなり、その全置換度が２．５６〜３．００であることを特徴とする＜７＞に記載の光学フイルム。
＜９＞
セルロースアシレートのグルコース単位の２位の水酸基のアシル基による置換度をＤＳ２、３位の水酸基の置換度をＤＳ３、６位の水酸基のアシル基による置換度をＤＳ６としたときに、下記式（Ｉ）および（ＩＩ）を満たすことを特徴とする＜７＞又は＜８＞に記載の光学フイルム。
式（Ｉ）：２．０≦（ＤＳ２＋ＤＳ３＋ＤＳ６）≦３．０
式（ＩＩ）：ＤＳ６／（ＤＳ２＋ＤＳ３＋ＤＳ６）≧０．３１５
＜１０＞
アシル置換基が実質的にアセチル基、プロピオニル基及びブタノイル基から選ばれる少なくとも２種類からなり、その全置換度が２．５０〜３．００であることを特徴とする＜７＞〜＜９＞のいずれか１項に記載の光学フイルム。
＜１１＞
製造工程中にフイルムを延伸する延伸工程と収縮させる収縮工程とを含むことを特徴とする＜１＞〜＜１０＞のいずれか１項に記載の光学フイルムの製造方法。
＜１２＞
偏光膜と該偏光膜を挟持する一対の保護膜とを有する偏光板であって、前記保護膜の少なくとも一枚が＜１＞〜＜１０＞のいずれか１項に記載の光学フイルムであることを特徴とする偏光板。
＜１３＞
＜１＞〜＜１０＞のいずれか１項に記載の光学フイルムまたは＜１２＞に記載の偏光板を有することを特徴とする液晶表示装置。
＜１４＞
下記式（１０）、（１１）を満たす光学異方性層をさらに有する＜１３＞に記載の液晶表示装置。
式（１０） Ｒｔ（５５０）／Ｒｅ（５５０）＞１０
式（１１） Ｒｔｈ（６５０）−Ｒｔｈ（４５０）＜０
＜１５＞
前記液晶表示装置がＶＡモードであることを特徴とする＜１３＞又は＜１４＞に記載の液晶表示装置。
＜１６＞
＜１２＞に記載の偏光板をバックライト側に用いたことを特徴とする＜１３＞〜＜１５＞のいずれか１項に記載の液晶表示装置。
本発明は、上記＜１＞〜＜１６＞に係る発明であるが、以下、それ以外の事項（例えば、下記〔１〕〜〔１７〕）についても記載している。 The object of the present invention has been achieved by the following means.
<1>
An optical film comprising at least one compound represented by the following general formula (I) and at least one Rth increasing agent.
Formula (I)

(In the general formula (I), L ₁ and L ₂ each represent a single bond or a divalent linking group. A ₁ and A ₂ are —O— and —NR— (R is a hydrogen atom or a substituent). R ₂ and R ₃ each represent a cyclohexane ring having a 4-alkylcyclohexyl group at the 4-position as a substituent, R ₁ and R _4. And R ₅ represents a substituent, and n represents an integer of 0 to 2.)
<2>
<1> The optical film according to <1>, comprising at least one selected from compounds represented by the following general formula (II), (III), (IV), or (V).
Formula (II)

(In the general formula (II) , each R ¹² independently represents an aromatic ring or a heterocyclic ring having a substituent in at least one of the ortho position, the meta position and the para position. X ¹¹ each independently represents Represents a single bond or —NR ¹³ — , wherein each R ¹³ independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, an alkenyl group, an aryl group or a heterocyclic group.
Formula (III)

(In the general formula (III), R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ each independently represents a hydrogen atom or a substituent.)
Formula (IV)
Q ⁷¹ -Q ⁷² -OH
(In the general formula (IV), Q ⁷¹ is a nitrogen-containing aromatic heterocyclic ring, Q ⁷² represents an aromatic ring.)
Formula (V):

(In the general formula (V), Q ⁸¹ and Q ⁸² each independently represents an aromatic ring. X ⁸¹ represents NR ⁸¹ (R ⁸¹ represents a hydrogen atom or a substituent), an oxygen atom or a sulfur atom.)
<3>
The optical film according to <1> or <2>, wherein at least one of the low molecular compound and the Rth increasing agent exhibits a liquid crystal phase in a temperature range of 100 ° C to 300 ° C.
<4>
<1>-<3> any one of <1>-<3> characterized by satisfy | filling following formula (1)-(3).
Formula (1) Re (550)> 20 nm
Formula (2) 0.5 <Nz <10
Formula (3) −2.5 × Re (550) +300 <Rth (550) <− 2.5 × Re (550) +500
(In the formula, Re (λ) and Rth (λ) are in-plane and out-of-plane retardation (unit: n) measured by incidence of light having a wavelength of λ nm, respectively, and Nz = Rth (550) / Re ( 550) +0.5)
<5>
<1>-<3> The optical film of any one of <1>-<3> characterized by satisfy | filling following formula (A)-(D).
(A) 0.1 <Re (450) / Re (550) <0.95
(B) 1.03 <Re (650) / Re (550) <1.93
(C) 0.4 <(Re / Rth (450)) / (Re / Rth (550)) <0.95
(D) 1.05 <(Re / Rth (650)) / (Re / Rth (550)) <1.9
(Where Re (λ) is the in-plane retardation value of the film with respect to light of wavelength λ nm, Rth (λ) is the retardation value in the thickness direction of the film with respect to light of wavelength λ nm, and Re / Rth (λ) is the ratio of the in-plane retardation value of the film to the retardation value in the thickness direction with respect to light having a wavelength of λ nm (unit: nm).
<6>
<1>-<5> The optical film according to any one of <1> to <5>, which is produced by a production method including a drawing step of drawing a film and a shrinking step of shrinking the film.
<7>
The optical film according to any one of <1> to <6>, wherein the optical film is made of cellulose acylate.
<8>
<7> The optical film according to <7>, wherein the acyl substituent of the cellulose acylate is substantially composed only of an acetyl group, and the total substitution degree is 2.56 to 3.00.
<9>
When the substitution degree of the hydroxyl group at the 2-position of the glucose unit of the cellulose acylate is DS2, the substitution degree of the hydroxyl group at the 3-position is DS3, and the substitution degree of the hydroxyl group at the 6-position is DS6, the following formula ( <7> or <8>, wherein the optical film satisfies I) and (II).
Formula (I): 2.0 ≦ (DS2 + DS3 + DS6) ≦ 3.0
Formula (II): DS6 / (DS2 + DS3 + DS6) ≧ 0.315
<10>
<7> to <9>, wherein the acyl substituent is substantially composed of at least two kinds selected from an acetyl group, a propionyl group, and a butanoyl group, and the total degree of substitution is 2.50 to 3.00. The optical film according to any one of the above.
<11>
<1>-<10> The manufacturing method of the optical film of any one of <1>-<10> characterized by including the extending process which stretches a film in a manufacturing process, and the shrinking process to shrink | contract.
<12>
A polarizing plate having a polarizing film and a pair of protective films sandwiching the polarizing film, wherein at least one of the protective films is the optical film according to any one of <1> to <10>. A polarizing plate characterized by.
<13>
A liquid crystal display device comprising the optical film according to any one of <1> to <10> or the polarizing plate according to <12>.
<14>
The liquid crystal display device according to <13>, further including an optically anisotropic layer satisfying the following formulas (10) and (11).
Formula (10) Rt (550) / Re (550)> 10
Formula (11) Rth (650) -Rth (450) <0
<15>
The liquid crystal display device according to <13> or <14>, wherein the liquid crystal display device is in a VA mode.
<16>
The liquid crystal display device according to any one of <13> to <15>, wherein the polarizing plate according to <12> is used on a backlight side.
The present invention is an invention according to the above <1> to <16>, but hereinafter, other matters (for example, the following [1] to [17]) are also described.

[1]
The molecular absorption wavelength derived from the transition electric dipole moment My in the direction substantially perpendicular to the molecular long axis direction is longer than the molecular absorption wavelength derived from the transition electric dipole moment Mx in the direction substantially parallel to the molecular long axis direction. The magnitude of the transition electric dipole moment | My | in the direction substantially perpendicular to the molecular long axis direction is larger than the magnitude | Mx | of the transition electric dipole moment in the direction substantially parallel to the molecular long axis direction. An optical film comprising at least one low-molecular compound and at least one Rth raising agent.
[2]
An optical film comprising at least one compound represented by the following general formula (I) and at least one Rth increasing agent.
Formula (I)

(In the general formula (I), L ₁ and L ₂ each represent a single bond or a divalent linking group. A ₁ and A ₂ are —O— and —NR— (R is a hydrogen atom or a substituent). , -S -, - CO- is chosen groups each independently of the _{.R 1, R 2, R 3} , R 4 and _{R 5} .n representing the substituent is an integer from 0 to 2).
[3]
[1] or [2], which contains at least one selected from compounds represented by the following general formula (II), (III), (IV), or (V) Optical film described in 1.
Formula (II)

(In the general formula (II), each R ¹² independently represents an aromatic ring or a heterocyclic ring having a substituent in at least one of the ortho position, the meta position and the para position. X ¹¹ each independently represents Represents a single bond or —NR ¹³ —, wherein each R ¹³ independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, an alkenyl group, an aryl group or a heterocyclic group.
Formula (III)

(In the general formula (III), R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ each independently represents a hydrogen atom or a substituent.)
Formula (IV)
Q ⁷¹ -Q ⁷² -OH
(In the general formula (IV), Q ⁷¹ is a nitrogen-containing aromatic heterocyclic ring, Q ⁷² represents an aromatic ring.)
Formula (V):

(In the general formula (V), Q ⁸¹ and Q ⁸² each independently represents an aromatic ring. X ⁸¹ represents NR ⁸¹ (R ⁸¹ represents a hydrogen atom or a substituent), an oxygen atom or a sulfur atom.)
[4]
The optical film according to any one of [1] to [3], wherein at least one of the low molecular weight compound and the Rth increasing agent exhibits a liquid crystal phase in a temperature range of 100 ° C to 300 ° C.
[5]
The optical film according to any one of [1] to [4], wherein the following formulas (1) to (3) are satisfied.
Formula (1) Re (550)> 20 nm
Formula (2) 0.5 <Nz <10
Formula (3) −2.5 × Re (550) +300 <Rth (550) <− 2.5 × Re (550) +500
(In the formula, Re (λ) and Rth (λ) are in-plane and out-of-plane retardation (unit: n) measured by incidence of light having a wavelength of λ nm, respectively, and Nz = Rth (550) / Re ( 550) +0.5)
[6]
The optical film according to any one of [1] to [4], wherein the following formulas (A) to (D) are satisfied.
(A) 0.1 <Re (450) / Re (550) <0.95
(B) 1.03 <Re (650) / Re (550) <1.93
(C) 0.4 <(Re / Rth (450)) / (Re / Rth (550)) <0.95
(D) 1.05 <(Re / Rth (650)) / (Re / Rth (550)) <1.9
(Where Re (λ) is the in-plane retardation value of the film with respect to light of wavelength λ nm, Rth (λ) is the retardation value in the thickness direction of the film with respect to light of wavelength λ nm, and Re / Rth (λ) is the ratio of the in-plane retardation value of the film to the retardation value in the thickness direction with respect to light having a wavelength of λ nm (unit: nm).
[7]
The optical film according to any one of [1] to [6], wherein the optical film is manufactured by a manufacturing method including a stretching process of stretching a film and a contracting process of contracting.
[8]
The optical film according to any one of [1] to [7], wherein the optical film is made of cellulose acylate.
[9]
[8] The optical film as described in [8], wherein the acyl substituent of cellulose acylate consists essentially of an acetyl group, and the total substitution degree is 2.56 to 3.00.
[10]
When the substitution degree of the hydroxyl group at the 2-position of the glucose unit of the cellulose acylate is DS2, the substitution degree of the hydroxyl group at the 3-position is DS3, and the substitution degree of the hydroxyl group at the 6-position is DS6, the following formula ( The optical film according to [8] or [9], wherein the optical film satisfies I) and (II).
Formula (I): 2.0 ≦ (DS2 + DS3 + DS6) ≦ 3.0
Formula (II): DS6 / (DS2 + DS3 + DS6) ≧ 0.315
[11]
[8] to [10], wherein the acyl substituent is substantially composed of at least two kinds selected from an acetyl group, a propionyl group and a butanoyl group, and the total substitution degree is 2.50 to 3.00. An optical film according to any one of the above.
[12]
The method for producing an optical film according to any one of [1] to [11], comprising a stretching process for stretching the film and a shrinking process for shrinking the film during the manufacturing process.
[13]
A polarizing plate having a polarizing film and a pair of protective films sandwiching the polarizing film, wherein at least one of the protective films is the optical film according to any one of [1] to [11] A polarizing plate characterized by.
[14]
A liquid crystal display device comprising the optical film according to any one of [1] to [11] or the polarizing plate according to [13].
[15]
The liquid crystal display device according to [14], further including an optically anisotropic layer satisfying the following formulas (10) and (11):
Formula (10) Rt (550) / Re (550)> 10
Formula (11) Rth (650) -Rth (450) <0
[16]
The liquid crystal display device according to any one of [14] and [15], wherein the liquid crystal display device is in a VA mode.
[17]
The liquid crystal display device according to any one of [14] to [16], wherein the polarizing plate according to [13] is used on a backlight side.

  In the present specification, “45 °”, “parallel” or “orthogonal” means that the angle is within a range of strictly less than ± 5 °. The error from the exact angle is preferably less than 4 °, more preferably less than 3 °. Regarding the angle, “+” means the clockwise direction, and “−” means the counterclockwise direction. Further, the “slow axis” means a direction in which the refractive index is maximized. The “visible light region” means 380 nm to 780 nm. Further, the measurement wavelength of the refractive index is a value at λ = 550 nm in the visible light region unless otherwise specified.

  In this specification, “polarizing plate” is cut into a size to be incorporated into a long polarizing plate and a liquid crystal device unless otherwise specified (in this specification, “cutting” includes “punching” and “cutting out”. It is used in the meaning including both of the polarizing plates. In this specification, “polarizing film” and “polarizing plate” are distinguished from each other, and “polarizing plate” is a laminate having a transparent protective film for protecting the polarizing film on at least one side of the “polarizing film”. Means.

In this specification, Re (λ) and Rth (λ) respectively represent front retardation and retardation in the film thickness direction at wavelength λ. Re (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in an automatic birefringence meter such as KOBRA 21ADH (manufactured by Oji Scientific Instruments). Rth (λ) is the wavelength from the direction inclined by + 40 ° with respect to the normal direction of the film, with Re (λ) and the in-plane slow axis (determined by an automatic birefringence meter, for example, KOBRA · 21ADH) as the tilt axis. Retardation value measured by making light of λ nm incident, and retardation measured by making light of wavelength λ nm incident from a direction inclined by −40 ° with respect to the film normal direction with the in-plane slow axis as the tilt axis An automatic birefringence meter, for example, KOBRA · 21ADH, is calculated based on the retardation values measured in a total of three directions.
Here, as the assumed value of the average refractive index, the values in the polymer handbook (JOHN WILEY & SONS, INC) and catalogs of various optical films can be used. Those whose average refractive index is not known can be measured with an Abbe refractometer. The average refractive index values of main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), Polystyrene (1.59). By inputting the assumed value of the average refractive index and the film thickness, an automatic birefringence meter such as KOBRA 21ADH calculates nx, ny, and nz. From this calculated nx, ny, and nz, Nz = (nx−Nz) / (nx−ny) is further calculated.

In this specification, the values of Re (450), Re (550), Re (650), Rth (450), Rth (550), and Rth (650) were obtained as follows. Measurement is performed using three or more different wavelengths (for example, λ = 479.2, 546.3, 632.8, and 745.3 nm) by a measurement apparatus, and Re and Rth are calculated from the respective wavelengths. These values are approximated by Cauchy's equation (up to the third term, Re = A + B / λ ² + C / λ ⁴ ) to obtain values A, B, and C. From the above, Re and Rth at the wavelength λ are re-plotted, and the Re and Rth values at the wavelengths of 450, 550, and 650 nm are Re (450), Re (550), Re (650), Rth (450), and Rth. (550), Rth (650) can be obtained.

  The optical film according to the present invention, a polarizing plate using the optical film, and a liquid crystal display device equipped with the optical film can obtain a high display quality image with little coloration when a black display is viewed from an oblique direction.

  In the present invention, the cellulose acylate film has optical characteristics in which the wavelength dispersion of the retardation is different between the normal direction and the oblique direction tilted with respect to the normal direction, for example, the polar angle direction of 60 degrees. It is characterized by positive use. The scope of the present invention is not limited by the display mode of the liquid crystal layer, and can be used for a liquid crystal display device having a liquid crystal layer of any display mode such as VA mode, IPS mode, ECB mode, TN mode, and OCB mode. .

  Details of the present invention will be described below.

  In the present invention, the molecular absorption wavelength derived from the transition electric dipole moment My substantially perpendicular to the molecular long axis direction is longer than the molecular absorption wavelength derived from the transition electric dipole moment Mx substantially parallel to the molecular long axis direction. The magnitude of the transition electric dipole moment | My | which is the wavelength and substantially perpendicular to the molecular long axis direction is greater than the magnitude | Mx | of the transition electric dipole moment substantially parallel to the molecular long axis direction. The present invention relates to an optical film characterized by containing at least one low molecular weight compound (hereinafter sometimes referred to as compound (A)) and at least one Rth raising agent.

  Hereinafter, the compound (A) contained in the optical film of the present invention will be described.

(Determination of molecular long axis)
The molecular long axis of the compound (A) used in the present invention can be determined by density functional calculation using a computer. That is, an optimized structure of a molecule is obtained by density functional calculation, and an axis connecting two atoms with the longest distance among arbitrary two-atom distances in the obtained molecular structure is defined as a molecular long axis.
In the construction of the molecular structure described above, GausView 3.0 (manufactured by Gaussain Inc.) is used. As a program used for molecular structure optimization, Gaussian 03 Rev. is used. D. 02 (manufactured by Gaussain Inc.), B3LYP / 6-31G (d) is used as the basis function, and the default value is used as the convergence condition.

(Transition electric dipole moments and their magnitudes, calculation of absorption wavelength derived from transition electric dipole moments)
The transition electric dipole moments Mx, My and their magnitudes | Mx |, | My |, and absorption wavelengths derived from Mx, My can be obtained by time-dependent density functional calculation. As a program used for time-dependent density functional calculation, Gaussian 03 Rev. D. 02 (manufactured by Gaussain Inc.), B3LYP / 6-31 + G (d) is used as a basis function, and a solvent effect is further introduced by the PCM method.
More specifically, from the inner product of the vector constituting the transition electric dipole moment obtained by the above calculation and the vector represented by the Cartesian coordinates of the atoms constituting both ends of the molecular long axis, the transition electric dipole moment and the above The angle formed with the molecular long axis is determined, and based on these, the molecular absorption wavelength derived from Mx, My and | Mx |, | My |, Mx and My is determined.

  In the present invention, the term “transition electric dipole moment substantially perpendicular to the molecular long axis direction” does not mean a transition electric dipole moment that forms an angle of 90 ° with the molecular long axis direction. This refers to the largest transition electric dipole moment among all the transition electric dipole moments that form an angle of 70 ° to 110 ° with the direction substantially parallel to the direction.

As already described, one of the characteristics of the compound (A) used in the optical film of the present invention is that the molecular absorption wavelength derived from the transition electric dipole moment My in the direction substantially perpendicular to the molecular long axis direction is such that the molecular long axis is The wavelength is longer than the molecular absorption wavelength derived from the transition electric dipole moment Mx in a direction substantially parallel to the direction.
Here, the absorption wavelength derived from the transition electric dipole moment Mx substantially orthogonal to the molecular long axis direction is 10 nm to 200 nm longer than the absorption wavelength derived from the transition electric dipole moment My substantially parallel to the molecular long axis direction. Preferably, the long wavelength is 20 nm or more and 150 nm or less, and more preferably 30 nm or more and 120 nm or less.
The absorption wavelength derived from the transition electric dipole moment My substantially orthogonal to the major axis direction is preferably in the range of 250 nm to 400 nm, more preferably in the range of 300 nm to 380 nm, and more preferably in the range of 320 nm to 375 nm. More preferably, it is in the range.

  Another feature of the compound (A) used in the optical film of the present invention is that the transition electric dipole moment magnitude | My | that is substantially orthogonal to the molecular long axis direction is a transition electric power that is substantially parallel to the molecular long axis direction. The magnitude of the dipole moment is larger than | Mx |. That is, the ratio (| My | / | Mx |) of both is preferably 1 or more, more preferably 1 or more and 50 or less, and further preferably 1.1 or more and 30 or less.

The compound (A) used for the optical film of the present invention is a low molecular compound. Here, the low molecular weight compound is a compound having a molecular weight of 1500 or less, more preferably 1200 or less, and still more preferably 1000 or less.
A compound having a molecular weight larger than the molecular weight within the above range is not preferred because bleeding is likely to occur.

In order to obtain the effect of the present invention, that is, the effect of reducing coloring when viewed from an oblique direction during black display of the liquid crystal display device, the in-plane retardation Re of the optical compensation film used for this is in the visible light range. On the other hand, it is preferable to increase depending on the wavelength.
In the following description, the refractive index or birefringence of the optical film varies depending on the light in the visible light range (that is, depending on the measurement wavelength). In particular, the optical film has the ability to increase the refractive index or birefringence of the optical film depending on its wavelength with respect to the light in the visible light range. Having the ability to reduce refraction depending on the wavelength of light in the visible light region is called “having forward wavelength dispersion”.
In order to obtain the effect of the present invention, the polymer composition is subjected to an orientation treatment such as stretching, and the orientation control direction by stretching or the like (hereinafter referred to as TD direction) is a positive direction. The refraction (Δn) is preferably reverse wavelength dispersion.
Here, Δn is a value obtained by subtracting the refractive index in the MD direction from the refractive index in the TD direction. For this reason, in order to make Δn reverse wavelength dispersion, the wavelength dispersion in the MD direction is more drastically lower than the wavelength dispersion of the refractive index in the TD direction (that is, the value of each refractive index with respect to the measurement wavelength is When the short wavelength side is plotted on the left and the long wavelength side is plotted on the right, the amount of decrease in the refractive index is large in the MD direction).

  The wavelength dispersion of the refractive index is closely related to the absorption waveform of the substance as represented by the Lorentz-Lorenz equation, and the wavelength dispersion of the refractive index in the MD direction is more right than the wavelength dispersion in the TD direction. In order to reduce the shoulder, it is only necessary to make the absorption transition wavelength in the MD direction longer than that in the TD direction.

In the present invention, a compound such as compound (A) is added to the polymer material, and further subjected to orientation treatment such as stretching, thereby making the absorption transition wavelength in the MD direction longer than that in the TD direction. It is possible to do.
That is, when the compound (A) is added in a polymer material and subjected to a stretching treatment, the molecular major axis of the compound (A) is oriented in the TD direction. As described above, in the compound (A), the molecular absorption wavelength derived from the transition electric dipole moment My in the direction substantially orthogonal to the molecular long axis direction becomes the transition electric dipole moment Mx in the direction substantially parallel to the molecular long axis direction. The magnitude of the transition electric dipole moment | My | which is longer than the molecular absorption wavelength derived from and is substantially perpendicular to the molecular long axis direction is substantially parallel to the molecular long axis direction. Greater than | Mx |. For this reason, it is possible to make the absorption transition wavelength in the MD direction longer than that in the TD direction.

  The compound (A) is preferably a compound represented by the following general formula (I), but is not limited thereto.

Below, the compound of general formula (I) is demonstrated in detail.
Formula (I):

(In the general formula (I), L ₁ and L ₂ each represent a single bond or a divalent linking group. A ₁ and A ₂ are —O— and —NR— (R is a hydrogen atom or a substituent). , -S -, - CO- is chosen groups each independently of the _{.R 1, R 2, R 3} , R 4 and _{R 5} .n representing the substituent is an integer from 0 to 2).

L ₁ and L ₂ are preferably the following examples.

  More preferred are -O-, -COO-, and -OCO-.

R ₁ is a substituent, and when a plurality of R ₁ are present, they may be the same or different and may form a ring. The following can be applied as examples of the substituent.

  A halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an alkyl group (preferably an alkyl group having 1 to 30 carbon atoms, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a tert- Butyl group, n-octyl group, 2-ethylhexyl group), cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms such as cyclohexyl group, cyclopentyl group, 4-n-dodecylcyclohexyl) Group), a bicycloalkyl group (preferably a substituted or unsubstituted bicycloalkyl group having 5 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom from a bicycloalkane having 5 to 30 carbon atoms. , Bicyclo [1,2,2] heptan-2-yl, bicyclo [2,2,2] octane-3-yl), a A kenyl group (preferably a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, such as a vinyl group or an allyl group), a cycloalkenyl group (preferably a substituted or unsubstituted cycloalkenyl group having 3 to 30 carbon atoms, That is, it is a monovalent group in which one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms is removed, for example, a 2-cyclopenten-1-yl, 2-cyclohexen-1-yl group), a bicycloalkenyl group (substituted or substituted). An unsubstituted bicycloalkenyl group, preferably a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, that is, a monovalent group in which one hydrogen atom of a bicycloalkene having one double bond is removed. Bicyclo [2,2,1] hept-2-en-1-yl group, bicyclo [2,2,2] oct-2-en-4-yl group), a Kiniru group (preferably a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, such as ethynyl group, propargyl group),

An aryl group (preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, such as a phenyl group, a p-tolyl group, a naphthyl group), a heterocyclic group (preferably a 5- or 6-membered substituted or unsubstituted aromatic group A monovalent group obtained by removing one hydrogen atom from an aromatic or non-aromatic heterocyclic compound, and more preferably a 5- or 6-membered aromatic heterocyclic group having 3 to 30 carbon atoms. 2-furyl group, 2-thienyl group, 2-pyrimidinyl group, 2-benzothiazolyl group), cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group (preferably substituted or unsubstituted having 1 to 30 carbon atoms) Alkoxy groups such as methoxy, ethoxy, isopropoxy, tert-butoxy, n-octyloxy, 2-methoxyethoxy), aryloxy Si group (preferably a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms such as phenoxy group, 2-methylphenoxy group, 4-tert-butylphenoxy group, 3-nitrophenoxy group, 2-tetradeca Noylaminophenoxy group), a silyloxy group (preferably a silyloxy group having 3 to 20 carbon atoms, such as trimethylsilyloxy group, tert-butyldimethylsilyloxy group), a heterocyclic oxy group (preferably having 2 to 30 carbon atoms) Substituted or unsubstituted heterocyclic oxy group, 1-phenyltetrazole-5-oxy group, 2-tetrahydropyranyloxy group), acyloxy group (preferably formyloxy group, substituted or unsubstituted alkyl group having 2 to 30 carbon atoms) Carbonyloxy group, substituted or unsubstituted arylcarboe having 6 to 30 carbon atoms Ruoxy group such as formyloxy group, acetyloxy group, pivaloyloxy group, stearoyloxy group, benzoyloxy group, p-methoxyphenylcarbonyloxy group), carbamoyloxy group (preferably substituted or unsubstituted having 1 to 30 carbon atoms) Carbamoyloxy group, for example, N, N-dimethylcarbamoyloxy group, N, N-diethylcarbamoyloxy group, morpholinocarbonyloxy group, N, N-di-n-octylaminocarbonyloxy group, Nn-octylcarbamoyl An oxy group), an alkoxycarbonyloxy group (preferably a substituted or unsubstituted alkoxycarbonyloxy group having 2 to 30 carbon atoms, such as a methoxycarbonyloxy group, an ethoxycarbonyloxy group, a tert-butoxycarbonyloxy group, an n-octyl group). Tilcarbonyloxy group), aryloxycarbonyloxy group (preferably a substituted or unsubstituted aryloxycarbonyloxy group having 7 to 30 carbon atoms, such as phenoxycarbonyloxy group, p-methoxyphenoxycarbonyloxy group, pn -Hexadecyloxyphenoxycarbonyloxy group),

An amino group (preferably an amino group, a substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted anilino group having 6 to 30 carbon atoms, such as an amino group, a methylamino group, a dimethylamino group; , Anilino group, N-methyl-anilino group, diphenylamino group), acylamino group (preferably formylamino group, substituted or unsubstituted alkylcarbonylamino group having 1 to 30 carbon atoms, substituted or unsubstituted 6 to 30 carbon atoms, or Unsubstituted arylcarbonylamino group, for example, formylamino group, acetylamino group, pivaloylamino group, lauroylamino group, benzoylamino group), aminocarbonylamino group (preferably substituted or unsubstituted amino acid having 1 to 30 carbon atoms) Carbonylamino group, for example, carbamoylamino group, N, N-dimethylamino Sulfonylamino group, N, N-diethylaminocarbonylamino group, morpholinocarbonylamino group), alkoxycarbonylamino group (preferably a substituted or unsubstituted alkoxycarbonylamino group having 2 to 30 carbon atoms, such as methoxycarbonylamino group, ethoxycarbonyl) Amino group, tert-butoxycarbonylamino group, n-octadecyloxycarbonylamino group, N-methyl-methoxycarbonylamino group), aryloxycarbonylamino group (preferably substituted or unsubstituted aryloxy having 7 to 30 carbon atoms) A carbonylamino group, such as a phenoxycarbonylamino group, a p-chlorophenoxycarbonylamino group, an mn-octyloxyphenoxycarbonylamino group, a sulfamoylamino group (preferably carbon 0-30 substituted or unsubstituted sulfamoylamino groups such as sulfamoylamino group, N, N-dimethylaminosulfonylamino group, Nn-octylaminosulfonylamino group), alkyl and arylsulfonylamino groups (Preferably substituted or unsubstituted alkylsulfonylamino having 1 to 30 carbon atoms, substituted or unsubstituted arylsulfonylamino group having 6 to 30 carbon atoms, for example, methylsulfonylamino group, butylsulfonylamino group, phenylsulfonylamino group 2,3,5-trichlorophenylsulfonylamino group, p-methylphenylsulfonylamino group),

A mercapto group, an alkylthio group (preferably a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms, such as a methylthio group, an ethylthio group or an n-hexadecylthio group), an arylthio group (preferably a substituted or unsubstituted group having 6 to 30 carbon atoms). A substituted arylthio group such as phenylthio group, p-chlorophenylthio group, m-methoxyphenylthio group), a heterocyclic thio group (preferably a substituted or unsubstituted heterocyclic thio group having 2 to 30 carbon atoms, such as 2 -Benzothiazolylthio group, 1-phenyltetrazol-5-ylthio group), sulfamoyl group (preferably a substituted or unsubstituted sulfamoyl group having 0 to 30 carbon atoms, such as N-ethylsulfamoyl group, N- ( 3-dodecyloxypropyl) sulfamoyl group, N, N-dimethylsulfamoyl group, -Acetylsulfamoyl group, N-benzoylsulfamoyl group, N- (N′phenylcarbamoyl) sulfamoyl group), sulfo group, alkyl and arylsulfinyl group (preferably substituted or unsubstituted having 1 to 30 carbon atoms) An alkylsulfinyl group, a 6-30 substituted or unsubstituted arylsulfinyl group such as a methylsulfinyl group, ethylsulfinyl group, phenylsulfinyl group, p-methylphenylsulfinyl group), alkyl and arylsulfonyl groups (preferably having a carbon number) 1-30 substituted or unsubstituted alkylsulfonyl groups, 6-30 substituted or unsubstituted arylsulfonyl groups such as methylsulfonyl group, ethylsulfonyl group, phenylsulfonyl group, p-methylphenylsulfonyl group), acyl groups (Good Or a formyl group, a substituted or unsubstituted alkylcarbonyl group having 2 to 30 carbon atoms, a substituted or unsubstituted arylcarbonyl group having 7 to 30 carbon atoms (eg, acetyl group, pivaloylbenzoyl group), aryloxycarbonyl Group (preferably a substituted or unsubstituted aryloxycarbonyl group having 7 to 30 carbon atoms, such as phenoxycarbonyl group, o-chlorophenoxycarbonyl group, m-nitrophenoxycarbonyl group, p-tert-butylphenoxycarbonyl group) An alkoxycarbonyl group (preferably a substituted or unsubstituted alkoxycarbonyl group having 2 to 30 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, a tert-butoxycarbonyl group, or an n-octadecyloxycarbonyl group),

Carbamoyl group (preferably a substituted or unsubstituted carbamoyl group having 1 to 30 carbon atoms, such as carbamoyl group, N-methylcarbamoyl group, N, N-dimethylcarbamoyl group, N, N-di-n-octylcarbamoyl group N- (methylsulfonyl) carbamoyl group), aryl and heterocyclic azo group (preferably substituted or unsubstituted arylazo group having 6 to 30 carbon atoms, substituted or unsubstituted heterocyclic azo group having 3 to 30 carbon atoms, For example, phenylazo group, p-chlorophenylazo group, 5-ethylthio-1,3,4-thiadiazol-2-ylazo group), imide group (preferably N-succinimide group, N-phthalimide group), phosphino group (preferably Is a substituted or unsubstituted phosphino group having 2 to 30 carbon atoms, such as a dimethylphosphino group, di Phenylphosphino group, methylphenoxyphosphino group), phosphinyl group (preferably a substituted or unsubstituted phosphinyl group having 2 to 30 carbon atoms, such as phosphinyl group, dioctyloxyphosphinyl group, diethoxyphosphinyl group), Phosphinyloxy group (preferably a substituted or unsubstituted phosphinyloxy group having 2 to 30 carbon atoms, such as diphenoxyphosphinyloxy group, dioctyloxyphosphinyloxy group), phosphinylamino group (Preferably a substituted or unsubstituted phosphinylamino group having 2 to 30 carbon atoms, such as a dimethoxyphosphinylamino group or a dimethylaminophosphinylamino group), a silyl group (preferably having 3 to 30 carbon atoms) Substituted or unsubstituted silyl groups such as trimethylsilyl group, tert-butyl Methylsilyl group, a phenyl dimethylsilyl group).

  Among the above substituents, those having a hydrogen atom may be substituted with the above groups after removing this. Examples of such functional groups include an alkylcarbonylaminosulfonyl group, an arylcarbonylaminosulfonyl group, an alkylsulfonylaminocarbonyl group, and an arylsulfonylaminocarbonyl group. Examples thereof include a methylsulfonylaminocarbonyl group, a p-methylphenylsulfonylaminocarbonyl group, an acetylaminosulfonyl group, and a benzoylaminosulfonyl group.

R ₁ is preferably a halogen atom, alkyl group, alkenyl group, aryl group, heterocyclic group, hydroxyl group, carboxyl group, alkoxy group, aryloxy group, acyloxy group, cyano group, amino group, more preferably A halogen atom, an alkyl group, a cyano group, and an alkoxy group.

R ₂ and R ₃ each independently represents a substituent. An example of R ₁ is given as an example. Preferred are a substituted or unsubstituted benzene ring and a substituted or unsubstituted cyclohexane ring. More preferred are a benzene ring having a substituent and a cyclohexane ring having a substituent, and more preferred are a benzene ring having a substituent at the 4-position and a cyclohexane ring having a substituent at the 4-position.

R ₄ and R ₅ each independently represents a substituent. An example of R ₁ is given as an example. Preferably, it is preferred that substituent constant sigma _p value of Hammett is greater than zero electron withdrawing group, sigma _p value has an electron withdrawing substituent of 0 to 1.5 Further preferred. Examples of such a substituent include a trifluoromethyl group, a cyano group, a carbonyl group, and a nitro group. R ₄ and R ₅ may be bonded to form a ring.
As for Hammett's substituent constants σ _p and σ _m , for example, Naoki Inamoto's “Hammett's rule-structure and reactivity-” (Maruzen), edited by the Chemical Society of Japan “New Experimental Chemistry Course 14 Synthesis of Organic Compounds” “Reaction V”, page 2605 (Maruzen), Tadao Nakatani, “Description of theoretical organic chemistry”, page 217 (Tokyo Kagaku Dojin), Chemical Review, 91, 165-195 (1991). .

A ₁ and A ₂ are groups independently selected from —O—, —NR— (R is a hydrogen atom or a substituent), —S—, and —CO—. Preferably, it is a group independently selected from -O-, -NR- (R is a substituent), and -S-.

  n is preferably 0 or 1, and most preferably 0.

  Hereinafter, the composition of the present invention will be described in detail with respect to the compound represented by the general formula (I) contained in at least one kind, but the present invention is not limited to the following specific examples. There is nothing. Regarding the following compounds, unless otherwise specified, the number in parentheses () indicates the exemplified compound (X).

  The synthesis of the compound represented by the general formula (I) or (II) can be performed with reference to known methods. For example, exemplary compound (16) of general formula (I) can be synthesized according to the following scheme.

  The synthesis from compound (1-A) to compound (1-C) is described in “Journal of Chemical Crystallography” (1997); 27 (9); p.515-526. Can be carried out by the method described in 1.

In the above scheme, the synthesis from the compound (1-A) to the compound (1-D) is described in “Journal of Chemical Crystallography” (1997); 27 (9); p.515-526. It can be performed with reference to the method described in 1.
Further, as shown in the above scheme, methanesulfonic acid chloride was added to a tetrahydrofuran solution of the compound (1-E), N, N-diisopropylethylamine was added dropwise and stirred, and then N, N-diisopropylethylamine was added. Exemplary solution (1) can be obtained by adding dropwise a tetrahydrofuran solution of compound (1-D) and then adding a tetrahydrofuran solution of N, N-dimethylaminopyridine (DMAP).

  As the compound (A) used in the optical film of the present invention, an anthraquinone derivative can be preferably used in addition to the compound represented by the general formula (I).

  Specific examples of the anthraquinone derivative that can be used in the present invention include, but are not limited to, the following compounds.

  In the present invention, the content of the compound represented by the compound (A) or the general formula (I) is preferably 0.1 to 30 parts by mass, and 0.5 to 20 parts by mass with respect to the cellulose compound. More preferably, it is 1 to 12 parts by mass, and most preferably 1 to 5 parts by mass.

  The compound represented by the compound (A) or the general formula (I) preferably exhibits a liquid crystal phase in a temperature range of 100 ° C to 300 ° C. More preferably, it is 120 degreeC-200 degreeC. The liquid crystal phase is preferably a nematic phase or a smectic phase.

The Rth raising agent to be contained in the optical film of the present invention together with the compound represented by the compound (A) or the general formula (I) will be described in detail below.
The Rth raising agent of the present invention preferably satisfies the following mathematical formulas (1) and (2).
(1) (Rth (a) −Rth (0)) / a ≧ 5.0
(2) 0.01 ≦ A ≦ 30
here,
Rth (a): Rth (nm) at a wavelength of 550 nm of a film containing A% retardation increasing agent
Rth (0): Rth (nm) at a wavelength of 550 nm of a film containing no retardation increasing agent
a: The mass (%) of the Rth increasing agent when the film raw material cellulose acylate is 100 parts by mass.

The mathematical formula (1) is further preferably the following mathematical formula (1a).
(1a) (Rth (a) −Rth (0)) / a ≧ 10.0
The mathematical formula (1) is most preferably the following mathematical formula (1b).
(1a) (Rth (a) −Rth (0)) / a ≧ 15.0

  In the present invention, the Rth increasing agent preferably has at least one absorption maximum at 250 to 380 nm, and more preferably has at least one absorption maximum at 250 to 360 nm. Most preferably, it has at least one absorption maximum between 300 and 355 nm.

  In the present invention, the Rth raising agent is preferably a compound having at least two aromatic rings.

  The Rth raising agent is preferably selected from compounds represented by the general formulas (II), (III), (IV), and (V).

The compound represented by formula (II) will be described.
Formula (II)

In the above general formula (II):
R ¹² each independently represents an aromatic ring or a heterocyclic ring having a substituent in at least one of the ortho position, meta position and para position.
X ¹¹ each independently represents a single bond or —NR ¹³ —. Here, each R ¹³ independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, an alkenyl group, an aryl group, or a heterocyclic group.

The aromatic ring represented by R ¹² is preferably phenyl or naphthyl, and particularly preferably phenyl. The aromatic ring represented by R ¹² may have at least one substituent at any substitution position. Examples of the substituent include a halogen atom, hydroxyl, cyano, nitro, carboxyl, alkyl group, alkenyl group, aryl group, alkoxy group, alkenyloxy group, aryloxy group, acyloxy group, alkoxycarbonyl group, alkenyloxycarbonyl group , Aryloxycarbonyl group, sulfamoyl group, alkyl-substituted sulfamoyl group, alkenyl-substituted sulfamoyl group, aryl-substituted sulfamoyl group, sulfonamide group, carbamoyl, alkyl-substituted carbamoyl group, alkenyl-substituted carbamoyl group, aryl-substituted carbamoyl group, amide group, alkylthio group , An alkenylthio group, an arylthio group, and an acyl group.

The heterocyclic group represented by R ¹² preferably has aromaticity. The heterocycle having aromaticity is generally an unsaturated heterocycle, preferably a heterocycle having the largest number of double bonds. The heterocyclic ring is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and most preferably a 6-membered ring. The hetero atom of the heterocyclic ring is preferably a nitrogen atom, a sulfur atom or an oxygen atom, and particularly preferably a nitrogen atom. As the heterocyclic ring having aromaticity, a pyridine ring (2-pyridyl or 4-pyridyl as the heterocyclic group) is particularly preferable. The heterocyclic group may have a substituent. Examples of the substituent of the heterocyclic group are the same as the examples of the substituent of the aryl moiety.
When X ¹¹ is a single bond, the heterocyclic group is preferably a heterocyclic group having a free valence on the nitrogen atom. The heterocyclic group having a free valence on the nitrogen atom is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and a 5-membered ring. Is most preferred. The heterocyclic group may have a plurality of nitrogen atoms. In addition, the heterocyclic group may have a hetero atom other than the nitrogen atom (eg, O, S). Examples of heterocyclic groups having free valences on nitrogen atoms are shown below.

In the general formula (II), X ¹¹ represents a single bond or —NR ¹³ —. R ¹³ independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, an alkenyl group, an aryl group, or a heterocyclic group.
The alkyl group represented by R ¹³ may be a cyclic alkyl group or a chain alkyl group, but a chain alkyl group is preferable, and a linear alkyl group is more preferable than a branched chain alkyl group. preferable. The number of carbon atoms in the alkyl group is preferably 1-30, more preferably 1-20, further preferably 1-10, still more preferably 1-8, and 1-6. Most preferred. The alkyl group may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (for example, methoxy group, ethoxy group) and an acyloxy group (for example, acryloyloxy group, methacryloyloxy group).

The alkenyl group represented by R ¹³ may be a cyclic alkenyl group or a chain alkenyl group, but preferably represents a chain alkenyl group, and is a straight chain alkenyl group rather than a branched chain alkenyl group. More preferably it represents a group. The number of carbon atoms in the alkenyl group is preferably 2 to 30, more preferably 2 to 20, still more preferably 2 to 10, still more preferably 2 to 8, 6 is most preferred. The alkenyl group may have a substituent. Examples of the substituent are the same as those of the alkyl group described above.
The aromatic ring group and heterocyclic group represented by R ¹³ are the same as the aromatic ring and heterocyclic ring represented by R ¹² , and the preferred range is also the same. The aromatic ring group and the heterocyclic group may further have a substituent, and examples of the substituent are the same as those of the aromatic ring and heterocyclic ring of R ¹² .

  Specific examples of the retardation increasing agent represented by the general formula (II) used in the present invention are shown below. Several R shown in the same structural formula in each exemplary compound means the same group. The definition of R is shown after the formula together with the specific example number.

II- (1) Phenyl
II- (2) 3-Ethoxycarbonylphenyl
II- (3) 3-Butoxyphenyl
II- (4) m-biphenylyl
II- (5) 3-Phenylthiophenyl
II- (6) 3-Chlorophenyl
II- (7) 3-Benzoylphenyl
II- (8) 3-Acetoxyphenyl
II- (9) 3-Benzoyloxyphenyl
II- (10) 3-phenoxycarbonylphenyl
II- (11) 3-methoxyphenyl
II- (12) 3-anilinophenyl
II- (13) 3-Isobutyrylaminophenyl
II- (14) 3-phenoxycarbonylaminophenyl
II- (15) 3- (3-Ethylureido) phenyl
II- (16) 3- (3,3-diethylureido) phenyl
II- (17) 3-Methylphenyl
II- (18) 3-phenoxyphenyl
II- (19) 3-Hydroxyphenyl

II- (20) 4-Ethoxycarbonylphenyl
II- (21) 4-Butoxyphenyl
II- (22) p-biphenylyl
II- (23) 4-Phenylthiophenyl
II- (24) 4-Chlorophenyl
II- (25) 4-Benzoylphenyl
II- (26) 4-Acetoxyphenyl
II- (27) 4-Benzoyloxyphenyl
II- (28) 4-phenoxycarbonylphenyl
II- (29) 4-methoxyphenyl
II- (30) 4-anilinophenyl
II- (31) 4-isobutyrylaminophenyl
II- (32) 4-phenoxycarbonylaminophenyl
II- (33) 4- (3-Ethylureido) phenyl
II- (34) 4- (3,3-diethylureido) phenyl
II- (35) 4-Methylphenyl
II- (36) 4-phenoxyphenyl
II- (37) 4-hydroxyphenyl

II- (38) 3,4-diethoxycarbonylphenyl
II- (39) 3,4-Dibutoxyphenyl
II- (40) 3,4-Diphenylphenyl
II- (41) 3,4-Diphenylthiophenyl
II- (42) 3,4-dichlorophenyl
II- (43) 3,4-Dibenzoylphenyl
II- (44) 3,4-diacetoxyphenyl
II- (45) 3,4-Dibenzoyloxyphenyl
II- (46) 3,4-diphenoxycarbonylphenyl
II- (47) 3,4-dimethoxyphenyl
II- (48) 3,4-dianilinophenyl
II- (49) 3,4-Dimethylphenyl
II- (50) 3,4-Diphenoxyphenyl
II- (51) 3,4-Dihydroxyphenyl
II- (52) 2-Naphthyl

II- (53) 3,4,5-triethoxycarbonylphenyl
II- (54) 3,4,5-Tributoxyphenyl
II- (55) 3,4,5-triphenylphenyl
II- (56) 3,4,5-triphenylthiophenyl
II- (57) 3,4,5-trichlorophenyl
II- (58) 3,4,5-Tribenzoylphenyl
II- (59) 3,4,5-triacetoxyphenyl
II- (60) 3,4,5-tribenzoyloxyphenyl
II- (61) 3,4,5-Triphenoxycarbonylphenyl
II- (62) 3,4,5-trimethoxyphenyl
II- (63) 3,4,5-trianilinophenyl
II- (64) 3,4,5-trimethylphenyl
II- (65) 3,4,5-Triphenoxyphenyl
II- (66) 3,4,5-trihydroxyphenyl

II- (67) phenyl
II- (68) 3-Ethoxycarbonylphenyl
II- (69) 3-butoxyphenyl
II- (70) m-biphenylyl
II- (71) 3-Phenylthiophenyl
II- (72) 3-Chlorophenyl
II- (73) 3-Benzoylphenyl
II- (74) 3-acetoxyphenyl
II- (75) 3-Benzoyloxyphenyl
II- (76) 3-phenoxycarbonylphenyl
II- (77) 3-methoxyphenyl
II- (78) 3-anilinophenyl
II- (79) 3-isobutyrylaminophenyl
II- (80) 3-phenoxycarbonylaminophenyl
II- (81) 3- (3-Ethylureido) phenyl
II- (82) 3- (3,3-diethylureido) phenyl
II- (83) 3-Methylphenyl
II- (84) 3-phenoxyphenyl
II- (85) 3-Hydroxyphenyl

II- (86) 4-Ethoxycarbonylphenyl
II- (87) 4-Butoxyphenyl
II- (88) p-biphenylyl
II- (89) 4-phenylthiophenyl
II- (90) 4-Chlorophenyl
II- (91) 4-Benzoylphenyl
II- (92) 4-acetoxyphenyl
II- (93) 4-Benzoyloxyphenyl
II- (94) 4-phenoxycarbonylphenyl
II- (95) 4-methoxyphenyl
II- (96) 4-anilinophenyl
II- (97) 4-Isobutyrylaminophenyl
II- (98) 4-phenoxycarbonylaminophenyl
II- (99) 4- (3-ethylureido) phenyl
II- (100) 4- (3,3-diethylureido) phenyl
II- (101) 4-Methylphenyl
II- (102) 4-phenoxyphenyl
II- (103) 4-hydroxyphenyl

II- (104) 3,4-diethoxycarbonylphenyl
II- (105) 3,4-Dibutoxyphenyl
II- (106) 3,4-diphenylphenyl
II- (107) 3,4-diphenylthiophenyl
II- (108) 3,4-dichlorophenyl
II- (109) 3,4-Dibenzoylphenyl
II- (110) 3,4-diacetoxyphenyl
II- (111) 3,4-Dibenzoyloxyphenyl
II- (112) 3,4-Diphenoxycarbonylphenyl
II- (113) 3,4-Dimethoxyphenyl
II- (114) 3,4-dianilinophenyl
II- (115) 3,4-Dimethylphenyl
II- (116) 3,4-Diphenoxyphenyl
II- (117) 3,4-dihydroxyphenyl
II- (118) 2-Naphthyl

II- (119) 3,4,5-triethoxycarbonylphenyl
II- (120) 3,4,5-Tributoxyphenyl
II- (121) 3,4,5-Triphenylphenyl
II- (122) 3,4,5-Triphenylthiophenyl
II- (123) 3,4,5-trichlorophenyl
II- (124) 3,4,5-tribenzoylphenyl
II- (125) 3,4,5-Triacetoxyphenyl
II- (126) 3,4,5-tribenzoyloxyphenyl
II- (127) 3,4,5-Triphenoxycarbonylphenyl
II- (128) 3,4,5-trimethoxyphenyl
II- (129) 3,4,5-trianilinophenyl
II- (130) 3,4,5-trimethylphenyl
II- (131) 3,4,5-Triphenoxyphenyl
II- (132) 3,4,5-trihydroxyphenyl

II- (133) phenyl
II- (134) 4-Butylphenyl
II- (135) 4- (2-methoxy-2-ethoxyethyl) phenyl
II- (136) 4- (5-Nonenyl) phenyl
II- (137) p-biphenylyl
II- (138) 4-Ethoxycarbonylphenyl
II- (139) 4-Butoxyphenyl
II- (140) 4-Methylphenyl
II- (141) 4-chlorophenyl
II- (142) 4-Phenylthiophenyl
II- (143) 4-Benzoylphenyl
II- (144) 4-Acetoxyphenyl
II- (145) 4-Benzoyloxyphenyl
II- (146) 4-phenoxycarbonylphenyl
II- (147) 4-methoxyphenyl
II- (148) 4-anilinophenyl
II- (149) 4-Isobutyrylaminophenyl
II- (150) 4-phenoxycarbonylaminophenyl
II- (151) 4- (3-Ethylureido) phenyl
II- (152) 4- (3,3-diethylureido) phenyl
II- (153) 4-phenoxyphenyl
II- (154) 4-Hydroxyphenyl

II- (155) 3-Butylphenyl
II- (156) 3- (2-methoxy-2-ethoxyethyl) phenyl
II- (157) 3- (5-Nonenyl) phenyl
II- (158) m-biphenylyl
II- (159) 3-Ethoxycarbonylphenyl
II- (160) 3-butoxyphenyl
II- (161) 3-Methylphenyl
II- (162) 3-chlorophenyl
II- (163) 3-phenylthiophenyl
II- (164) 3-Benzoylphenyl
II- (165) 3-Acetoxyphenyl
II- (166) 3-Benzoyloxyphenyl
II- (167) 3-phenoxycarbonylphenyl
II- (168) 3-methoxyphenyl
II- (169) 3-anilinophenyl
II- (170) 3-isobutyrylaminophenyl
II- (171) 3-phenoxycarbonylaminophenyl
II- (172) 3- (3-ethylureido) phenyl
II- (173) 3- (3,3-diethylureido) phenyl
II- (174) 3-phenoxyphenyl
II- (175) 3-hydroxyphenyl

II- (176) 2-Butylphenyl
II- (177) 2- (2-methoxy-2-ethoxyethyl) phenyl
II- (178) 2- (5-Nonenyl) phenyl
II- (179) o-biphenylyl
II- (180) 2-ethoxycarbonylphenyl
II- (181) 2-Butoxyphenyl
II- (182) 2-methylphenyl
II- (183) 2-chlorophenyl
II- (184) 2-Phenylthiophenyl
II- (185) 2-benzoylphenyl
II- (186) 2-Acetoxyphenyl
II- (187) 2-Benzoyloxyphenyl
II- (188) 2-phenoxycarbonylphenyl
II- (189) 2-methoxyphenyl
II- (190) 2-anilinophenyl
II- (191) 2-isobutyrylaminophenyl
II- (192) 2-phenoxycarbonylaminophenyl
II- (193) 2- (3-ethylureido) phenyl
II- (194) 2- (3,3-diethylureido) phenyl
II- (195) 2-phenoxyphenyl
II- (196) 2-hydroxyphenyl

II- (197) 3,4-dibutylphenyl
II- (198) 3,4-di (2-methoxy-2-ethoxyethyl) phenyl
II- (199) 3,4-diphenylphenyl
II- (200) 3,4-diethoxycarbonylphenyl
II- (201) 3,4-didodecyloxyphenyl
II- (202) 3,4-dimethylphenyl
II- (203) 3,4-dichlorophenyl
II- (204) 3,4-Dibenzoylphenyl
II- (205) 3,4-diacetoxyphenyl
II- (206) 3,4-Dimethoxyphenyl
II- (207) 3,4-Di-N-methylaminophenyl
II- (208) 3,4-Diisobutyrylaminophenyl
II- (209) 3,4-Diphenoxyphenyl
II- (210) 3,4-Dihydroxyphenyl

II- (211) 3,5-dibutylphenyl
II- (212) 3,5-di (2-methoxy-2-ethoxyethyl) phenyl
II- (213) 3,5-diphenylphenyl
II- (214) 3,5-diethoxycarbonylphenyl
II- (215) 3,5-didodecyloxyphenyl
II- (216) 3,5-dimethylphenyl
II- (217) 3,5-dichlorophenyl
II- (218) 3,5-dibenzoylphenyl
II- (219) 3,5-diacetoxyphenyl
II- (220) 3,5-dimethoxyphenyl
II- (221) 3,5-di-N-methylaminophenyl
II- (222) 3,5-diisobutyrylaminophenyl
II- (223) 3,5-diphenoxyphenyl
II- (224) 3,5-dihydroxyphenyl

II- (225) 2,4-dibutylphenyl
II- (226) 2,4-di (2-methoxy-2-ethoxyethyl) phenyl
II- (227) 2,4-diphenylphenyl
II- (228) 2,4-diethoxycarbonylphenyl
II- (229) 2,4-didodecyloxyphenyl
II- (230) 2,4-Dimethylphenyl
II- (231) 2,4-dichlorophenyl
II- (232) 2,4-Dibenzoylphenyl
II- (233) 2,4-diacetoxyphenyl
II- (234) 2,4-dimethoxyphenyl
II- (235) 2,4-di-N-methylaminophenyl
II- (236) 2,4-diisobutyrylaminophenyl
II- (237) 2,4-diphenoxyphenyl
II- (238) 2,4-dihydroxyphenyl

II- (239) 2,3-dibutylphenyl
II- (240) 2,3-di (2-methoxy-2-ethoxyethyl) phenyl
II- (241) 2,3-diphenylphenyl
II- (242) 2,3-diethoxycarbonylphenyl
II- (243) 2,3-didodecyloxyphenyl
II- (244) 2,3-Dimethylphenyl
II- (245) 2,3-dichlorophenyl
II- (246) 2,3-dibenzoylphenyl
II- (247) 2,3-diacetoxyphenyl
II- (248) 2,3-dimethoxyphenyl
II- (249) 2,3-di-N-methylaminophenyl
II- (250) 2,3-diisobutyrylaminophenyl
II- (251) 2,3-diphenoxyphenyl
II- (252) 2,3-dihydroxyphenyl

II- (253) 2,6-dibutylphenyl
II- (254) 2,6-di (2-methoxy-2-ethoxyethyl) phenyl
II- (255) 2,6-diphenylphenyl
II- (256) 2,6-diethoxycarbonylphenyl
II- (257) 2,6-didodecyloxyphenyl
II- (258) 2,6-dimethylphenyl
II- (259) 2,6-dichlorophenyl
II- (260) 2,6-dibenzoylphenyl
II- (261) 2,6-diacetoxyphenyl
II- (262) 2,6-dimethoxyphenyl
II- (263) 2,6-di-N-methylaminophenyl
II- (264) 2,6-diisobutyrylaminophenyl
II- (265) 2,6-diphenoxyphenyl
II- (266) 2,6-dihydroxyphenyl

II- (267) 3,4,5-tributylphenyl
II- (268) 3,4,5-tri (2-methoxy-2-ethoxyethyl) phenyl
II- (269) 3,4,5-triphenylphenyl
II- (270) 3,4,5-triethoxycarbonylphenyl
II- (271) 3,4,5-tridodecyloxyphenyl
II- (272) 3,4,5-trimethylphenyl
II- (273) 3,4,5-trichlorophenyl
II- (274) 3,4,5-tribenzoylphenyl
II- (275) 3,4,5-triacetoxyphenyl
II- (276) 3,4,5-trimethoxyphenyl
II- (277) 3,4,5-Tri-N-methylaminophenyl
II- (278) 3,4,5-triisobutyrylaminophenyl
II- (279) 3,4,5-Triphenoxyphenyl
II- (280) 3,4,5-Trihydroxyphenyl

II- (281) 2,4,6-tributylphenyl
II- (282) 2,4,6-tri (2-methoxy-2-ethoxyethyl) phenyl
II- (283) 2,4,6-triphenylphenyl
II- (284) 2,4,6-triethoxycarbonylphenyl
II- (285) 2,4,6-tridodecyloxyphenyl
II- (286) 2,4,6-trimethylphenyl
II- (287) 2,4,6-trichlorophenyl
II- (288) 2,4,6-tribenzoylphenyl
II- (289) 2,4,6-triacetoxyphenyl
II- (290) 2,4,6-trimethoxyphenyl
II- (291) 2,4,6-tri-N-methylaminophenyl
II- (292) 2,4,6-triisobutyrylaminophenyl
II- (293) 2,4,6-triphenoxyphenyl
II- (294) 2,4,6-trihydroxyphenyl

II- (295) pentafluorophenyl
II- (296) pentachlorophenyl
II- (297) pentamethoxyphenyl
II- (298) 6-N-methylsulfamoyl-8-methoxy-2-naphthyl
II- (299) 5-N-methylsulfamoyl-2-naphthyl
II- (300) 6-N-phenylsulfamoyl-2-naphthyl
II- (301) 5-Ethoxy-7-N-methylsulfamoyl-2-naphthyl
II- (302) 3-methoxy-2-naphthyl
II- (303) 1-ethoxy-2-naphthyl
II- (304) 6-N-phenylsulfamoyl-8-methoxy-2-naphthyl
II- (305) 5-methoxy-7-N-phenylsulfamoyl-2-naphthyl
II- (306) 1- (4-methylphenyl) -2-naphthyl
II- (307) 6,8-di-N-methylsulfamoyl-2-naphthyl
II- (308) 6-N-2-acetoxyethylsulfamoyl-8-methoxy-2-naphthyl
II- (309) 5-acetoxy-7-N-phenylsulfamoyl-2-naphthyl
II- (310) 3-Benzoyloxy-2-naphthyl

II- (311) 5-acetylamino-1-naphthyl
II- (312) 2-methoxy-1-naphthyl
II- (313) 4-phenoxy-1-naphthyl
II- (314) 5-N-methylsulfamoyl-1-naphthyl
II- (315) 3-N-methylcarbamoyl-4-hydroxy-1-naphthyl
II- (316) 5-methoxy-6-N-ethylsulfamoyl-1-naphthyl
II- (317) 7-tetradecyloxy-1-naphthyl
II- (318) 4- (4-Methylphenoxy) -1-naphthyl
II- (319) 6-N-methylsulfamoyl-1-naphthyl
II- (320) 3-N, N-dimethylcarbamoyl-4-methoxy-1-naphthyl
II- (321) 5-methoxy-6-N-benzylsulfamoyl-1-naphthyl
II- (322) 3,6-di-N-phenylsulfamoyl-1-naphthyl

II- (323) methyl
II- (324) ethyl
II- (325) butyl
II- (326) octyl
II- (327) Dodecyl
II- (328) 2-butoxy-2-ethoxyethyl
II- (329) benzyl
II- (330) 4-methoxybenzyl

II- (331) methyl
II- (332) phenyl
II- (333) butyl
II- (334); compound of the following chemical formula

The compound represented by general formula (III) is demonstrated below.
Formula (III)

In the formula, R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ each independently represent a hydrogen atom or a substituent.
As the substituents represented by R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ , an alkyl group (preferably having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably carbon number). 1-20 alkyl groups, such as methyl, ethyl, isopropyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc. ), An alkenyl group (preferably an alkenyl group having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, and particularly preferably 2 to 20 carbon atoms, such as a vinyl group, an allyl group, and 2-butenyl. Group, 3-pentenyl group and the like), alkynyl group (preferably having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, particularly preferably 2 to 20 carbon atoms). A quinyl group, for example, a propargyl group, a 3-pentynyl group, and the like; an aryl group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and particularly preferably 6 to 12 carbon atoms). Group, for example, a phenyl group, a p-methylphenyl group, a naphthyl group and the like, a substituted or unsubstituted amino group (preferably having 0 to 40 carbon atoms, more preferably 0 to 30 carbon atoms, and particularly preferably Is an amino group having 0 to 20 carbon atoms, and examples thereof include an unsubstituted amino group, a methylamino group, a dimethylamino group, a diethylamino group, and an anilino group).

An alkoxy group (preferably an alkoxy group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, and a butoxy group). Aryloxy group (preferably an aryloxy group having 6 to 40 carbon atoms, more preferably 6 to 30 carbon atoms, particularly preferably 6 to 20 carbon atoms, and examples thereof include a phenyloxy group and a 2-naphthyloxy group. An acyl group (preferably an acyl group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and particularly preferably 1 to 20 carbon atoms, such as an acetyl group, a benzoyl group, a formyl group, and a pivaloyl group. Etc.), an alkoxycarbonyl group (preferably having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, and particularly preferably carbon number) To 20 alkoxy groups such as methoxycarbonyl group and ethoxycarbonyl group), aryloxycarbonyl groups (preferably having 7 to 40 carbon atoms, more preferably having 7 to 30 carbon atoms, and particularly preferably carbon atoms). An aryloxycarbonyl group having 7 to 20 carbon atoms, such as a phenyloxycarbonyl group, and an acyloxy group (preferably having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, and particularly preferably 2 carbon atoms). ˜20 acyloxy groups such as an acetoxy group and a benzoyloxy group)

An acylamino group (preferably an acylamino group having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, particularly preferably 2 to 20 carbon atoms, such as an acetylamino group and a benzoylamino group), alkoxycarbonyl An amino group (preferably an alkoxycarbonylamino group having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, particularly preferably 2 to 20 carbon atoms, such as a methoxycarbonylamino group), aryloxy Carbonylamino group (preferably an aryloxycarbonylamino group having 7 to 40 carbon atoms, more preferably 7 to 30 carbon atoms, particularly preferably 7 to 20 carbon atoms, such as a phenyloxycarbonylamino group) Sulfonylamino group (preferably having 1 to 40 carbon atoms, more preferred Or a sulfonylamino group having 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, such as a methanesulfonylamino group and a benzenesulfonylamino group, and a sulfamoyl group (preferably having a carbon number of 0 to 40). More preferably, it is a sulfamoyl group having 0 to 30 carbon atoms, particularly preferably 0 to 20 carbon atoms, and examples thereof include a sulfamoyl group, a methylsulfamoyl group, a dimethylsulfamoyl group, and a phenylsulfamoyl group. ), A carbamoyl group (preferably a carbamoyl group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, for example, an unsubstituted carbamoyl group, a methylcarbamoyl group, diethylcarbamoyl group Group, phenylcarbamoyl group, etc.),

An alkylthio group (preferably having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, such as a phenylthio group), a sulfonyl group (preferably having 1 to 1 carbon atoms). 40, more preferably a sulfonyl group having 1 to 30 carbon atoms, particularly preferably a sulfonyl group having 1 to 20 carbon atoms, such as a mesyl group and a tosyl group, and a sulfinyl group (preferably having a carbon number of 1 to 40, more Preferably it is C1-C30, Most preferably, it is C1-C20 sulfinyl group, for example, a methane sulfinyl group, a benzene sulfinyl group, etc., a ureido group (preferably C1-C40, more preferable) Is a ureido group having 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, such as an unsubstituted ureido group or methylurea. And phosphoric acid amide groups (preferably having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and particularly preferably 1 to 20 carbon atoms), For example, a diethylphosphoric acid amide group, a phenylphosphoric acid amide group etc. are mentioned), a hydroxy group, a mercapto group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), a cyano group, a sulfo group, a carboxyl group , A nitro group, a hydroxamic acid group, a sulfino group, a hydrazino group, an imino group, a heterocyclic group (preferably a heterocyclic group having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms such as a nitrogen atom, an oxygen atom, A heterocyclic group having a heteroatom such as a sulfur atom, such as an imidazolyl group, a pyridyl group, a quinolyl group, a furyl group, a piperidyl group Morpholino group, benzoxazolyl group, benzimidazolyl group, benzthiazolyl group, 1,3,5-triazyl group, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms). Particularly preferred is a silyl group having 3 to 24 carbon atoms, and examples thereof include a trimethylsilyl group and a triphenylsilyl group. These substituents may be further substituted with these substituents. Further, when two or more substituents are present, they may be the same or different. If possible, they may be bonded to each other to form a ring.

The substituent represented by each of R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ is preferably an alkyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an alkylthio group or a halogen atom. It is.

    Although the specific example of a compound represented by general formula (III) below is given, it is not limited to this.

The compound represented by general formula (IV) is demonstrated below.
Formula ^{(IV): Q 71 -Q 72} -OH
(Wherein, Q ⁷¹ is a nitrogen-containing aromatic heterocyclic ring, Q ⁷² represents an aromatic ring.)
In formula (IV), Q ⁷¹ represents a nitrogen-containing heterocycle direction aromatic, preferably a nitrogen-containing aromatic heterocyclic 5- to 7-membered, more preferably 5- to 6-membered nitrogen-containing aromatic heterocyclic It is a ring.

  Preferred nitrogen-containing aromatic heterocycles include, for example, imidazole, pyrazole, triazole, tetrazole, thiazole, oxazole, selenazole, benzotriazole, benzothiazole, benzoxazole, benzoselenazole, thiadiazole, oxadiazole, naphthothiazole, naphthoxazole , Azabenzimidazole, purine, pyridine, pyrazine, pyrimidine, pyridazine, triazine, triazaindene, tetrazaindene, and the like, more preferably triazine and a 5-membered nitrogen-containing aromatic heterocycle. Specifically, 1,3,5-triazine, imidazole, pyrazole, triazole, tetrazole, thiazole, oxazole, benzotriazole, benzothiazole, benzoxa Lumpur, thiadiazole, each ring such as oxadiazole Preferably, particularly preferably a 1,3,5-triazine ring and a benzotriazole ring.

Nitrogen-containing aromatic heterocyclic ring represented by Q ⁷¹ may have a substituent, and the substituent may be the substituent T described later. In addition, when there are a plurality of substituents, each may be condensed to form a ring.

Q ⁷² represents an aromatic ring. The aromatic ring represented by Q ⁷² may be an aromatic hydrocarbon ring or an aromatic heterocycle. These may be monocyclic or may form a condensed ring with another ring. The aromatic hydrocarbon ring is preferably a monocyclic or bicyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms (such as a benzene ring or a naphthalene ring), more preferably 6 to 20 carbon atoms. An aromatic hydrocarbon ring, more preferably an aromatic hydrocarbon ring having 6 to 12 carbon atoms. More preferred is a benzene ring.

  The aromatic heterocycle is preferably an aromatic heterocycle containing a nitrogen atom or a sulfur atom. Specific examples of the heterocyclic ring include, for example, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiazoline, thiazole, thiadiazole, oxazoline, oxazole, oxadiazole, quinoline, isoquinoline, Examples include phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole, benzthiazole, benzotriazole, and tetrazaindene. Preferred examples of the aromatic heterocycle include pyridine, triazine, and quinoline.

The aromatic ring represented by Q ^72, is preferably an aromatic hydrocarbon ring, more preferably a naphthalene ring, a benzene ring, particularly preferably a benzene ring. Q ⁷² may further have a substituent, and the following substituent T is preferred.
Examples of the substituent T include alkyl groups (preferably those having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms such as a methyl group, an ethyl group, an isopropyl group, and a t-butyl group. , N-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2). For example, vinyl group, allyl group, 2-butenyl group, 3-pentenyl group, etc.), alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms). , For example, propargyl group, 3-pentynyl group, etc.), aryl group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 and particularly preferably 6 to 12). Yes, for example, a phenyl group, a biphenyl group, a naphthyl group, etc., an amino group (preferably having a carbon number of 0-20, more preferably 0-10, particularly preferably 0-6, for example, an amino group, a methylamino group, a dimethyl group) An amino group, a diethylamino group, a dibenzylamino group, etc.), an alkoxy group (preferably having a carbon number of 1-20, more preferably 1-12, particularly preferably 1-8, such as a methoxy group, an ethoxy group, a butoxy group, etc. ), An aryloxy group (preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms such as a phenyloxy group and a 2-naphthyloxy group), an acyl group (preferably having a carbon number). 1-20, more preferably 1-16, particularly preferably 1-12. For example, acetyl, benzoyl, formyl, A loyl group, etc.), an alkoxycarbonyl group (preferably having a carbon number of 2-20, more preferably 2-16, particularly preferably 2-12, such as a methoxycarbonyl group, an ethoxycarbonyl group, etc.), an aryloxycarbonyl group (preferably Has 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 10 carbon atoms, such as a phenyloxycarbonyl group, an acyloxy group (preferably 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly Preferably it is 2-10, for example, acetoxy group, benzoyloxy group, etc.)

An acylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms such as an acetylamino group and a benzoylamino group), an alkoxycarbonylamino group (preferably having 2 to 20 carbon atoms) , More preferably 2 to 16, particularly preferably 2 to 12, for example, methoxycarbonylamino group and the like, aryloxycarbonylamino group (preferably 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 carbon atoms). -12, for example, phenyloxycarbonylamino group, etc., sulfonylamino group (preferably 1-20 carbon atoms, more preferably 1-16, particularly preferably 1-12, such as methanesulfonylamino group, benzenesulfonyl Amino groups, etc.), sulfamoyl groups (preferably having 0 to 20 carbon atoms, More preferably, it is 0-16, Most preferably, it is 0-12, for example, sulfamoyl group, methylsulfamoyl group, dimethylsulfamoyl group, phenylsulfamoyl group, etc.), carbamoyl group (preferably having 1 to 20 carbon atoms). More preferably 1 to 16, particularly preferably 1 to 12, for example, a carbamoyl group, a methylcarbamoyl group, a diethylcarbamoyl group, a phenylcarbamoyl group, etc., an alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1). -16, particularly preferably 1-12, for example, methylthio group, ethylthio group, etc.), arylthio group (preferably 6-20, more preferably 6-16, particularly preferably 6-12, such as phenylthio Group), a sulfonyl group (preferably having a carbon number of 1 to 20, more preferably 1 to 16, particularly preferably 1 to 12, and examples thereof include a mesyl group and a tosyl group.), A sulfinyl group (preferably having a carbon number of 1 to 20, more preferably 1 to 16, and particularly preferably 1 to 12). For example, methanesulfinyl group, benzenesulfinyl group, etc.), ureido group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16, particularly preferably 1 to 12, such as ureido group, methylureido group, phenyl Ureido group), phosphoric acid amide group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16, particularly preferably 1 to 12, such as diethyl phosphoric acid amide and phenylphosphoric acid amide),

Hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, hetero A cyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom, and a sulfur atom, specifically, for example, an imidazolyl group, a pyridyl group, a quinolyl group, Furyl group, piperidyl group, morpholino group, benzoxazolyl group, benzimidazolyl group, benzthiazolyl group, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms). For example, a trimethylsilyl group, a triphenylsilyl group, etc.).

  These substituents may be further substituted. Moreover, when there are two or more substituents, they may be the same or different. If possible, they may be linked together to form a ring.

  Specific examples of the compound represented by formula (IV) are given below, but the present invention is not limited to the following specific examples.

(Table 1)

The compound represented by general formula (V) is demonstrated below.
Formula (V):

{In General Formula (V), Q ⁸¹ and Q ⁸² each independently represent an aromatic ring. X ⁸¹ represents NR ⁸¹ (R ⁸¹ represents a hydrogen atom or a substituent), an oxygen atom or a sulfur atom. }
The aromatic hydrocarbon ring represented by Q ⁸¹ and Q ⁸² is preferably a monocyclic or bicyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms (for example, a benzene ring or a naphthalene ring), and more preferably An aromatic hydrocarbon ring having 6 to 20 carbon atoms, more preferably an aromatic hydrocarbon ring having 6 to 12 carbon atoms, and particularly preferably a benzene ring.

The aromatic heterocycle represented by Q ⁸¹ and Q ⁸² is preferably an aromatic heterocycle containing at least one of an oxygen atom, a nitrogen atom or a sulfur atom. Specific examples of the aromatic heterocycle include, for example, furan, pyrrole, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiazoline, thiazole, thiadiazole, oxazoline, oxazole, oxadi Examples include azole, quinoline, isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole, benzothiazole, benzotriazole, and tetrazaindene. The aromatic hetero ring is preferably a pyridine ring, a triazine ring or a quinoline ring.

The aromatic ring represented by Q ⁸¹ and Q ⁸² is preferably an aromatic hydrocarbon ring, more preferably an aromatic hydrocarbon ring having 6 to 10 carbon atoms, and still more preferably a substituted or unsubstituted benzene. It is a ring.

Q ⁸¹ and Q ⁸² may further have a substituent, and the substituent T is preferably the above-described substituent T, but the substituent does not include a carboxylic acid, a sulfonic acid, or a quaternary ammonium salt. Further, if possible, substituents may be linked to form a ring structure.

X ⁸¹ represents NR ⁸¹ (R ⁸¹ represents a hydrogen atom or a substituent, and the above substituent T can be applied as a substituent), an oxygen atom or a sulfur atom. X ⁸¹ is preferably NR ⁸¹ (R ⁸¹ is preferably an acyl group or a sulfonyl group, and these substituents may be further substituted) or an oxygen atom, and particularly preferably an oxygen atom.
Specific examples of the compound represented by formula (V) are shown below, but the present invention is not limited to the following specific examples.

  The Rth raising agent used in the present invention is more preferably a compound represented by the general formulas (II) and (III). Moreover, it is also preferably used to mix the compound represented by the general formula (IV) with the compound represented by the general formulas (II) and (III).

  The addition amount of the Rth raising agent and retardation enhancer (compound represented by the general formulas (II) to (IV)) used in the present invention is 0.1 to 30% by mass with respect to the base polymer of the film. More preferably, it is 0.5-20 mass%, Most preferably, it is 1-10 mass%. When using 2 or more types, it is preferable that the total amount satisfy | fills said range.

  The Rth increasing agent used in the present invention preferably exhibits liquid crystallinity. It is more preferable to exhibit liquid crystallinity (having thermotropic liquid crystallinity) by heating, and it is preferable to exhibit liquid crystallinity in a temperature range of 100 ° C to 300 ° C. The liquid crystal phase is preferably a columnar phase, a nematic phase or a smectic phase, and more preferably a columnar phase.

  The compound of the general formula (I) and the Rth raising agent may be added simultaneously with the dissolution of the base polymer of the film, or may be added to the dope after dissolution. In particular, a mode in which an ultraviolet absorbent solution is added to the dope immediately before casting using a static mixer or the like is preferable because spectral absorption characteristics can be easily adjusted.

(Cellulose acylate)
As the raw material cotton of cellulose acylate, a known raw material can be used (for example, refer to the Japanese Society for Invention and Innovation 2001-1745). Cellulose acylate can also be synthesized by a known method (for example, see Mita et al., Wood Chemistry pages 180-190 (Kyoritsu Shuppan, 1968)). The viscosity average polymerization degree of cellulose acylate is preferably 200 to 700, more preferably 250 to 500, and most preferably 250 to 350. The number average molecular weight (Mn) of the cellulose ester used in the present invention is preferably 10,000 to 150,000, the weight average molecular weight (Mw) is 20,000 to 500,000, and the Z average molecular weight (Mz) is preferably 5,000 to 550000. Moreover, it is preferable that the molecular weight distribution of Mw / Mn (Mw is a mass average molecular weight, Mn is a number average molecular weight) by gel permeation chromatography is narrow. The specific value of Mw / Mn is preferably 1.5 to 5.0, more preferably 2.0 to 4.5, and most preferably 3.0 to 4.0. preferable.

The acyl group of the cellulose acylate film is not particularly limited, but an acetyl group, propionyl group, butyryl group, or benzoyl group is preferably used. The substitution degree of all acyl groups is preferably 2.0 to 3.0, more preferably 2.2 to 2.95. In this specification, the substitution degree of an acyl group is a value calculated according to ASTM D817. The acyl group is most preferably an acetyl group, and in the case of using cellulose acetate in which the acyl group is an acetyl group, the acetylation degree is preferably 57.0 to 62.5%, and 58.0 More preferably, it is 62.0%. When the acetylation degree is within this range, Re does not become larger than the desired value due to the conveying tension during casting, there is little in-plane variation, and there is little change in the retardation value due to temperature and humidity.
In particular, it is obtained by substituting the hydroxyl group of the glucose unit constituting the cellulose of the cellulose acylate film with an acyl group having 2 or more carbon atoms, and the substitution degree of the 2-position hydroxyl group of the glucose unit with the acyl group is DS2, 3-position. When the degree of substitution of the hydroxyl group with an acyl group is DS3 and the degree of substitution of the hydroxyl group at the 6-position with DS6 is DS6, if the following formulas (IV) and (V) are satisfied, desired Re and Rth can be obtained. This is preferable because the change in the Re value due to temperature and humidity becomes smaller.
(IV): 2.0 ≦ (DS2 + DS3 + DS6) ≦ 3.0
(V): DS6 / (DS2 + DS3 + DS6) ≧ 0.315
A more preferred range is
(IV ′): 2.2 ≦ (DS2 + DS3 + DS6) ≦ 2.9
(V ′): DS6 / (DS2 + DS3 + DS6) ≧ 0.322
It is.

Or, in particular, when the degree of substitution of the hydroxyl group of the glucose unit of cellulose acylate with an acetyl group is A, and the degree of substitution with a propionyl group, butyryl group or benzoyl group is B, A and B are represented by the formulas (VI) and (VII): When it is satisfied, it becomes easy to obtain desired Re and Rth, and it is easy to realize a high draw ratio without breaking, which is preferable.
(VI): 2.0 ≦ A + B ≦ 3.0
(VII): 0 <B
A more preferred range is
(VI ′): 2.6 ≦ A + B ≦ 3.0
(VII ′): 0.5 ≦ B ≦ 1.5
It is.

(Polymers other than cellulose acylate)
According to the present invention, a method for obtaining a film having preferable optical properties by a production method characterized by comprising a stretching step for stretching a film and a shrinking step for shrinking is not limited to cellulose acylate, but as an optical film. It can be applied to all usable polymers and can be expected to have the same effect as cellulose acylate.
Examples of polymers that can be used as these optical films include polycarbonate copolymers and polymer resins having a cyclic olefin structure.

  Examples of the polycarbonate copolymer include a repeating unit represented by the following formula (A) and a repeating unit represented by the following formula (B), and the repeating unit represented by the above formula (A) is 80 to 30 mol in total. % Of the polycarbonate copolymer.

In the above formula (A), R _{1 to} R ₈ are each independently selected from a hydrogen atom, a halogen atom, and a hydrocarbon group having 1 to 6 carbon atoms. Examples of the hydrocarbon group having 1 to 6 carbon atoms include alkyl groups such as a methyl group, an ethyl group, an isopropyl group, and a cyclohexyl group, and an aryl group such as a phenyl group. Among these, a hydrogen atom and a methyl group are preferable.

X is the following formula (X), and R ₉ and R ₁₀ are each independently a hydrogen atom, a halogen atom, or an alkyl group having 1 to 3 carbon atoms. Examples of the alkyl group having 1 to 3 carbon atoms include the same ones as described above.

In the above formula (B), R _{11 to} R ₁₈ are each independently selected from a hydrogen atom, a halon atom, and a hydrocarbon group having 1 to 22 carbon atoms. Examples of the hydrocarbon group having 1 to 22 carbon atoms include alkyl groups having 1 to 9 carbon atoms such as a methyl group, an ethyl group, an isopropyl group, and a cyclohexyl group, and aryl groups such as a phenyl group, a biphenyl group, and a terphenyl group. It is done. Among these, a hydrogen atom and a methyl group are preferable.

Y is the following formula group, and R _{19 to} R ₂₁ , R ₂₃ and R ₂₄ are each independently at least one group selected from a hydrogen atom, a halogen atom and a hydrocarbon group having 1 to 22 carbon atoms. Examples of the hydrocarbon group include the same ones as described above. R ₂₂ and R ₂₅ are each independently selected from hydrocarbon groups having 1 to 20 carbon atoms, such as methylene, ethylene, propylene, butylene, cyclohexylene, phenylene, naphthylene, A terphenylene group is mentioned. Examples of Ar _{1 to} Ar ₃ include aryl groups having 6 to 10 carbon atoms such as a phenyl group and a naphthyl group.

  As said polycarbonate copolymer, the polycarbonate copolymer which consists of 30-60 mol% of repeating units shown by the following formula (C), and 70-40 mol% of repeating units shown by the following formula (D) is preferable.

  More preferably, it is a polycarbonate copolymer composed of 45 to 55 mol% of the repeating unit represented by the above formula (C) and 55 to 45 mol% of the repeating unit represented by the above formula (D).

In the above formula (C), R _{26 to} R ₂₇ are each independently a hydrogen atom or a methyl group, and preferably a methyl group from the viewpoint of handleability.

In the above formula (D), R _{28 to} R ₂₉ are each independently a hydrogen atom or a methyl group, and a hydrogen atom is preferred from the viewpoint of economy, film characteristics, and the like.

  The optical film of the present invention is preferably one using the above-described polycarbonate copolymer having a fluorene skeleton. As the polycarbonate copolymer having a fluorene skeleton, for example, a blend of polycarbonate copolymers having different composition ratios composed of the repeating unit represented by the above formula (A) and the repeating unit represented by the above formula (B) is often used. The content of the above formula (A) is preferably 80 to 30 mol%, more preferably 75 to 35 mol%, still more preferably 70 to 40 mol% of the entire polycarbonate copolymer.

  The copolymer may be a combination of two or more repeating units represented by the above formulas (A) and (B).

  Here, the molar ratio is a molar ratio with respect to the entire polycarbonate bulk constituting the optical film, and can be determined by, for example, a nuclear magnetic resonance (NMR) apparatus.

  The above polycarbonate copolymer can be produced by a known method. As the polycarbonate, a method by polycondensation of a dihydroxy compound and phosgene, a melt polycondensation method or the like is preferably used.

  The intrinsic viscosity of the polycarbonate copolymer is preferably 0.3 to 2.0 dl / g. If it is less than 0.3, there is a problem that it becomes brittle and the mechanical strength cannot be maintained. There is a problem of becoming.

The optical film of the present invention may be a composition (blend) of the polycarbonate copolymer and other polymer compounds. In this case, since the polymer compound needs to be optically transparent, it is preferable that the polymer compound is compatible with the polycarbonate copolymer, or the refractive index of each polymer is substantially equal. Specific examples of the other polymer include styrene-maleic anhydride copolymer, and the composition ratio of the polycarbonate copolymer to the polymer compound is 80 to 30% by mass of the polycarbonate copolymer. They are 20-70 mass%, Preferably they are a polycarbonate copolymer 80-40 mass%, and a high molecular compound body 20-60 mass%. Also in the case of a blend, two or more kinds of repeating units of the polycarbonate copolymer may be combined. In the case of a blend, a compatible blend is preferable. However, even if the blend is not completely compatible, the light scattering between the components can be suppressed and the transparency can be improved by adjusting the refractive index between the components. In addition, a blend body may combine 3 or more types of materials, and can combine multiple types of polycarbonate copolymer and another high molecular compound.
The weight average molecular weight of the polycarbonate copolymer is 1,000 to 1,000,000, preferably 5,000 to 500,000. The mass average molecular weight of the other polymer compound is 500 to 100,000, preferably 1,000 to 50,000.

  Polymers applicable to the present invention other than cellulose acylate include polymer resins having a cyclic olefin structure (hereinafter also referred to as “cyclic polyolefin resin” or “cyclic polyolefin”). Examples include (1) norbornene polymers, (2) monocyclic olefin polymers, (3) cyclic conjugated diene polymers, (4) vinyl alicyclic hydrocarbon polymers, and (1 ) To (4) hydrides. Preferred polymers for the present invention are addition (co) polymer cyclic polyolefins containing at least one repeating unit represented by the following general formula (II), and if necessary, a repeating unit represented by the general formula (I) An addition (co) polymer cyclic polyolefin further comprising at least one of the above. Further, addition (co) polymers (including ring-opening (co) polymers) containing at least one cyclic repeating unit represented by the general formula (III) can also be suitably used. The addition (co) polymer cyclic further contains at least one repeating unit represented by the general formula (III) and, if necessary, at least one repeating unit represented by the general formula (I). Polyolefins can also be preferably used.

In formula, m represents the integer of 0-4. R ^{1 to} R ⁶ are hydrogen atoms or hydrocarbon groups having 1 to 10 carbon atoms, X ^{1 to} X ³ and Y ^{1 to} Y ³ are hydrogen atoms, hydrocarbon groups having 1 to 10 carbon atoms, halogen atoms, halogen atoms in substituted hydrocarbon group having 1 to 10 carbon _{atoms, - (CH 2) n COOR} 11, - (CH 2) n OCOR 12, - (CH 2) n NCO, - (CH 2) n NO 2, - _{(CH 2) n CN, -} (CH 2) n CONR 13 R 14, - (CH 2) n NR 13 R 14, - (CH 2) n OZ, - (CH 2) n W or X ¹ and Y, ¹ , (—CO) ₂ O, (—CO) ₂ NR ¹⁵ composed of X ² and Y ² or X ³ and Y ³ is shown. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , and R ¹⁵ are hydrogen atoms, hydrocarbon groups having 1 to 20 carbon atoms, Z is a hydrocarbon group or a hydrocarbon group substituted with halogen, and W is SiR ¹⁶ _p. D _{3 -p} (R ¹⁶ is a hydrocarbon group having 1 to 10 carbon atoms, D is a halogen atom —OCOR ¹⁶ or —OR ¹⁶ , p is an integer of 0 to 3), n is an integer of 0 to 10 .

By introducing a polarizable large functional group in a substituent ^{X 1 ~X 3, Y 1 ~Y} 3, by increasing the thickness-direction retardation of the optical film (Rth), in-plane retardation (Re) The expression can be increased. A film having a high Re developability can increase the Re value by stretching in the film forming process.
Norbornene-based addition (co) polymers are disclosed in various publications such as JP-A No. 10-7732, JP-T No. 2002-504184, US2004229157A1 or WO2004 / 070463A1. It can be obtained by addition polymerization of norbornene-based polycyclic unsaturated compounds. If necessary, norbornene-based polycyclic unsaturated compounds and conjugated dienes such as ethylene, propylene, butene, butadiene and isoprene; non-conjugated dienes such as ethylidene norbornene; acrylonitrile, acrylic acid, methacrylic acid, maleic anhydride It is also possible to carry out addition polymerization with linear diene compounds such as acid, acrylic acid ester, methacrylic acid ester, maleimide, vinyl acetate and vinyl chloride. This norbornene-based addition (co) polymer is marketed by Mitsui Chemicals, Inc. under the name of Apel, and has different glass transition temperatures (Tg) such as APL8008T (Tg70 ° C), APL6013T (Tg125 ° C) or APL6015T ( Grades such as Tg145 ° C). Pellets are sold under the trade names such as TOPAS 8007, 6013, and 6015 from Polyplastics. Further, Appear 3000 is sold by Ferrania.

Norbornene polymer hydrides are disclosed in JP-A-1-240517, JP-A-7-196736, JP-A-60-26024, JP-A-62-19801, JP-A-2003-159767, JP-A-2004-309799. As disclosed in various publications such as No. 1, etc., it is prepared by addition polymerization or metathesis ring-opening polymerization of a polycyclic unsaturated compound and then hydrogenation. In the norbornene-based polymer used in the present invention, R ^{5 to} R ⁶ are preferably a hydrogen atom or —CH ₃ , X ³ and Y ³ are preferably a hydrogen atom, Cl, —COOCH ₃ , and other groups are appropriately selected. . This norbornene-based resin is sold under the trade name Arton G or Arton F by JSR Corporation, and from Zeon Corporation, Zeonor ZF14, ZF16, Zeonex 250 or Zeonex. They are commercially available under the trade name 280 and can be used.

The optical film of the present invention can also be used as a protective film for a polarizing plate, and can also be preferably used as a retardation film corresponding to various liquid crystal modes.
When the optical film of the present invention is used as a retardation film, preferred optical properties of the optical film vary depending on the liquid crystal mode.
For the OCB mode, Re (550) is preferably 10 to 100 nm, more preferably 20 to 70 nm in view of widening the viewing angle. Rth (550) is preferably 50 to 300 nm, more preferably 100 to 250 nm.
From the same viewpoint, for TN, Re (550) is preferably 0 to 50 nm, more preferably 2 to 30 nm. Rth (550) is preferably 10 to 200 nm, more preferably 30 to 150 nm.
Moreover, in the mode for OCB and the mode for TN, an optical anisotropic layer can be apply | coated on the optical film which has the said retardation value, and it can use as an optical compensation film.

  When the optical film of the present invention is used in the VA mode, a mode in which a total of two sheets are used on each side of the cell (two-sheet type) and a mode in which only one of the upper and lower sides of the cell is used (one sheet) The preferred optical characteristics are different in two types.

  In the case of the single sheet type used for the VA mode or the IPS mode, Re (550) is preferably 30 to 150 nm, and more preferably 40 to 100 nm. Rth (550) is preferably from 100 to 300 nm, more preferably from 150 to 250 nm.

  When used on both sides of a liquid crystal cell as an optical compensation film of a liquid crystal display device for VA and used as a two-sheet type, Re (550) is in the range of 20 to 100 nm, and Rth (550) is in the range of 100 to 200 nm. Preferably, Re (550) is 25 to 80 nm and Rth (550) is 100 to 150 nm.

In particular, when used as a two-sheet type, the optical film of the present invention preferably satisfies the following formulas (A) to (D) from the viewpoint of improving the aforementioned color shift problem.
(A) 0.1 <Re (450) / Re (550) <0.95
(B) 1.03 <Re (650) / Re (550) <1.93
(C) 0.4 <(Re / Rth (450)) / (Re / Rth (550)) <0.95
(D) 1.05 <(Re / Rth (650)) / (Re / Rth (550)) <1.9
(Where Re (λ) is the in-plane retardation value of the film with respect to light of wavelength λ nm, Rth (λ) is the retardation value in the thickness direction of the film with respect to light of wavelength λ nm, and Re / Rth (λ) is the ratio of the in-plane retardation value of the film to the retardation value in the thickness direction with respect to light having a wavelength of λ nm (unit: nm).

The film of the present invention satisfying the above formulas (A) to (D) can also be used as a single sheet used for the VA mode from the same viewpoint.
Furthermore, when the optical film of the present invention satisfying the above formulas (A) to (D) is used as a single sheet type, it is more preferable to satisfy the following formulas (A1) to (D1).
(A1) 0.4 <Re (450) / Re (550) <0.95
(B1) 1.05 <Re (650) / Re (550) <1.93
(C1) 0.45 <(Re / Rth (450)) / (Re / Rth (550)) <0.95
(D1) 1.05 <(Re / Rth (650)) / (Re / Rth (550)) <1.7

The optical film of the present invention more preferably satisfies the following formulas (A2) to (D2).
(A2) 0.5 <Re (450) / Re (550) <0.95
(B2) 1.10 <Re (650) / Re (550) <1.93
(C2) 0.50 <(Re / Rth (450)) / (Re / Rth (550)) <0.95
(D2) 1.05 <(Re / Rth (650)) / (Re / Rth (550)) <1.5

  In the present invention, by using the optical compensation film having the above-mentioned optical characteristics, optical compensation is performed with respect to R, G, and B wavelengths incident obliquely with different slow axes and retardations for each wavelength. Is possible. As a result, compared with the conventional liquid crystal display device, the viewing angle contrast of black display is remarkably improved, and coloring in the viewing angle direction of black display is also remarkably reduced. Here, in this specification, as wavelengths of R, G, and B, R has a wavelength of 650 nm, G has a wavelength of 550 nm, and B has a wavelength of 450 nm. The wavelengths of R, G, and B are not necessarily represented by these wavelengths, but are considered to be suitable wavelengths for defining the optical characteristics that exhibit the effects of the present invention.

  In addition, it is preferable that the birefringence ((DELTA) n: nx-ny) of an optical film exists in the range of 0.00 thru | or -0.002 micrometer. The birefringence {(nx + ny) / 2-nz} in the thickness direction of the support film and the counter film is preferably in the range of 0.00 to 0.04.

  The optical film of the present invention can be obtained by forming a film using a solution obtained by dissolving the specific cellulose acylate or the specific polymer and, if necessary, an additive in an organic solvent.

〔Additive〕
Examples of the additive that can be used in the cellulose acylate solution in the present invention include a plasticizer, an ultraviolet absorber, a deterioration preventing agent, a retardation (optical anisotropy) developing agent, and a retardation (optical anisotropy). Examples thereof include a reducing agent, a wavelength dispersion adjusting agent, a dye, fine particles, a peeling accelerator, and an infrared absorber. In the present invention, it is preferable to use a retardation developer. Moreover, it is preferable to use at least one of a plasticizer, an ultraviolet absorber and a peeling accelerator.

  They may be solid or oily. That is, the melting point and boiling point are not particularly limited. For example, ultraviolet absorbers of 20 ° C. or lower and 20 ° C. or higher can be mixed and used, and plasticizers can also be mixed and used, for example, as described in JP-A-2001-151901.

[Deterioration inhibitor]
The deterioration inhibitor can prevent cellulose triacetate and the like from deteriorating and decomposing. Examples of the deterioration preventing agent include butylamine, hindered amine compounds (JP-A-8-325537), guanidine compounds (JP-A-5-271471), benzotriazole-based UV absorbers (JP-A-6-235819), and benzophenone-based compounds. There are compounds such as UV absorbers (JP-A-6-118233).

[Plasticizer]
The plasticizer is preferably a phosphate ester or a carboxylic acid ester. Examples of the phosphate ester plasticizer include triphenyl phosphate (TPP), tricresyl phosphate (TCP), cresyl diphenyl phosphate, octyl diphenyl phosphate, biphenyl diphenyl phosphate (BDP), trioctyl phosphate, tributyl phosphate and the like; Examples of the acid ester plasticizer include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP), diethyl hexyl phthalate (DEHP), O-acetyl citrate. Triethyl acid (OACTE), O-acetyl tributyl citrate (OACTB), acetyl triethyl citrate, acetyl tributyl citrate, oleic acid , Acetyl ricinoleate, dibutyl sebacate, triacetin, tributyrin, butyl phthalyl butyl glycolate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, etc. The plasticizer used in the invention is more preferably selected from these exemplified plasticizers. Furthermore, the plasticizer is preferably (di) pentaerythritol esters, glycerol esters, diglycerol esters.

[Peeling accelerator]
Examples of the peeling accelerator include citric acid ethyl esters.
[Infrared absorber]
Furthermore, as an infrared absorber, it describes in Unexamined-Japanese-Patent No. 2001-194522, for example.

[Time of addition, etc.]
These additives may be added at any time in the dope preparation step, but may be added to the final preparation step of the dope preparation step by adding the additive preparation step. Furthermore, the amount of each material added is not particularly limited as long as the function is manifested.

  Moreover, when an optical film is a multilayer, the kind and addition amount of the additive of each layer may differ. For example, although described in Japanese Patent Application Laid-Open No. 2001-151902, these are conventionally known techniques.

  The glass transition point Tg measured by a dynamic viscoelasticity measuring device “Vibron: DVA-225” {manufactured by IT Measurement Control Co., Ltd.}} of a cellulose acylate film is selected by selecting the type and amount of these additives. It is preferable that the elastic modulus measured by a tensile tester “Strograph-R2” {manufactured by Toyo Seiki Seisakusho} is 1500 to 4000 MPa at ˜150 ° C. More preferably, the glass transition point Tg is 80 to 135 ° C. and the elastic modulus is 1500 to 3000 MPa. That is, it is preferable that the optical film preferably used in the present invention has the glass transition point Tg and the elastic modulus within the above ranges from the viewpoint of process suitability for polarizing plate processing and liquid crystal display device assembly.

  Further, as the additive, those described in detail on page 16 and subsequent pages of the Invention Association Public Technical Bulletin No. 2001-1745 (issued March 15, 2001, Invention Association) can be appropriately used.

(Log P value)
In producing an optical film having low optical anisotropy, as described above, a compound that reduces optical anisotropy by inhibiting cellulose acylate in the film from being oriented in the plane and in the film thickness direction. Of these, compounds having an octanol-water partition coefficient (log P value) of 0 to 7 are preferred. If the logP value of the compound is 7 or less, the compatibility with cellulose acylate and the like is good, and problems such as white turbidity and powder blowing of the film are less likely to occur.
Moreover, if the logP value of the compound is 0 or more, the hydrophilicity does not become too high and the water resistance of the cellulose acylate film is not deteriorated, which is preferable. A more preferable range for the logP value is 1 to 6, and a particularly preferable range is 1.5 to 5.

  The octanol-water partition coefficient (log P value) can be measured by a flask soaking method described in JIS Z-7260-107 (2000). Further, the octanol-water partition coefficient (log P value) can be estimated by a computational chemical method or an empirical method instead of the actual measurement.

  As a calculation method, the Crippen's fragmentation method {J. Chem. Inf. Comput. Sci. , 27, 21 (1987)}, Viswanadhan's fragmentation method {J. Chem. Inf. Comput. Sci. 29, 163 (1989)}, Broto's fragmentation method {Eur. J. et al. Med. Chem. -Chim. Theor. 19 (71) (1984)} is preferably used, but the Crippen's fragmentation method {J. Chem. Inf. Comput. Sci. 27, 21 (1987)}.

  When the log P value of a certain compound varies depending on the measurement method or calculation method, it is preferable to determine whether or not the compound is within the above range by the Crippen's fragmentation method.

[dye]
In the present invention, a dye for adjusting the hue may be added. The content of the dye is preferably 10 to 1000 ppm, more preferably 50 to 500 ppm in terms of a mass ratio with respect to a polymer such as cellulose acylate. By containing the dye in this way, light piping of the cellulose acylate film can be reduced, and yellowness can be improved. These compounds may be added together with cellulose acylate and a solvent during the preparation of the cellulose acylate solution, or may be added during or after the solution preparation. Moreover, you may add to the ultraviolet absorber liquid added in-line. The dyes described in JP-A-5-34858 can be used.

[Matting agent fine particles]
It is preferable to add fine particles as a matting agent to the optical film preferably used in the present invention. The fine particles used in the present invention include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate and Mention may be made of calcium phosphate. As the fine particles, those containing silicon are preferable in terms of low turbidity, and silicon dioxide is particularly preferable.

  The fine particles of silicon dioxide preferably have a primary average particle diameter of 20 nm or less and an apparent specific gravity of 70 g / L or more. Those having an average primary particle size as small as 5 to 16 nm are more preferred because they can reduce the haze of the film. The apparent specific gravity is preferably 90 to 200 g / L or more, and more preferably 100 to 200 g / L or more. A higher apparent specific gravity is preferable because a high-concentration dispersion can be produced, and haze and aggregates are improved.

  When silicon dioxide fine particles are used as the matting agent, the amount used is preferably 0.01 to 0.3 parts by mass with respect to 100 parts by mass of the polymer component containing cellulose acylate and the like.

  These fine particles usually form secondary particles having an average particle diameter of 0.1 to 3.0 μm, but are present as aggregates of primary particles in the film, and 0.1 to 3.0 μm on the film surface. Form irregularities. The average particle diameter of the secondary particles is preferably from 0.2 μm to 1.5 μm, more preferably from 0.4 μm to 1.2 μm, and most preferably from 0.6 μm to 1.1 μm. If the average particle diameter is 1.5 μm or less, the haze will not be too strong, and if it is 0.2 μm or more, the effect of preventing squeezing will be sufficiently exhibited, which is preferable.

  The primary and secondary particle diameters of the fine particles are determined by observing the particles in the film with a scanning electron microscope and using the diameter of a circle circumscribing the particles as the particle diameter. Also, 200 particles are observed at different locations, and the average value is taken as the average particle diameter.

  As the fine particles of silicon dioxide, for example, commercially available products such as “Aerosil” R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 {above, manufactured by Nippon Aerosil Co., Ltd.} can be used. . Zirconium oxide fine particles are commercially available under the trade names of “Aerosil” R976 and R811 {above, Nippon Aerosil Co., Ltd.}, and can be used.

  Among these, “Aerosil 200V” and “Aerosil R972V” are fine particles of silicon dioxide having a primary average particle diameter of 20 nm or less and an apparent specific gravity of 70 g / L or more, and the turbidity of the optical film is low. This is particularly preferable because the effect of reducing the coefficient of friction is large while maintaining it.

In the present invention, in order to obtain an optical film containing particles having a small secondary average particle size, several methods are conceivable when preparing a dispersion of fine particles. For example, a fine particle dispersion prepared by stirring and mixing a solvent and fine particles is prepared in advance, and this fine particle dispersion is added to a separately prepared small amount of cellulose acylate solution and stirred to dissolve, and further mixed with the main cellulose acylate dope solution. There is a way to do it. This method is a preferred preparation method in that the dispersibility of the silicon dioxide fine particles is good and the silicon dioxide fine particles are more difficult to reaggregate. In addition, after adding a small amount of cellulose ester to the solvent and dissolving with stirring, add the fine particles to this and disperse with a disperser to make this fine particle additive solution. There is also a method of mixing. In the present invention, although not limited to these methods, the concentration of silicon dioxide when the silicon dioxide fine particles are mixed and dispersed with a solvent or the like is preferably 5 to 30% by mass, and 10 to 25% by mass. Is more preferable, and 15 to 20% by mass is most preferable.
A higher dispersion concentration is preferable because the liquid turbidity with respect to the added amount is lowered, and haze and aggregates are improved. The addition amount of the matting agent in the final dope solution such as cellulose acylate is preferably 0.01 to 1.0 g, more preferably 0.03 to 0.3 g, more preferably 0.08 to 0.16 g per 1 m ^2. Is most preferred.

  The solvent used is preferably lower alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol and the like. Although it does not specifically limit as solvents other than a lower alcohol, It is preferable to use the solvent used at the time of film formation of a cellulose ester.

  Next, the organic solvent in which cellulose acylate and the like preferably used in the present invention are dissolved will be described.

  In the present invention, as the organic solvent, any of a chlorinated solvent containing a chlorinated organic solvent as a main solvent and a non-chlorinated solvent not containing a chlorinated organic solvent can be used.

[Chlorine solvent]
In preparing the cellulose acylate solution preferably used in the present invention, a chlorinated organic solvent is preferably used as the main solvent. In the present invention, the type of the chlorinated organic solvent is not particularly limited as long as the object can be achieved within a range in which the cellulose acylate can be dissolved and cast and formed. These chlorinated organic solvents are preferably dichloromethane and chloroform. Particularly preferred is dichloromethane. In addition, there is no particular problem in mixing an organic solvent other than the chlorinated organic solvent. In that case, it is preferable to use at least 50% by mass of dichloromethane in the total amount of the organic solvent.

Other organic solvents used in combination with the chlorinated organic solvent in the present invention will be described below.
That is, as another preferable organic solvent, a solvent selected from esters, ketones, ethers, alcohols, hydrocarbons and the like having 3 to 12 carbon atoms is preferable. The ester, ketone, ether and alcohol may have a cyclic structure. A compound having two or more functional groups of esters, ketones and ethers (that is, —O—, —CO— and —COO—) can also be used as a solvent. You may have a functional group simultaneously. In the case of a solvent having two or more types of functional groups, the number of carbon atoms may be within the specified range of the compound having any functional group. Examples of the esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate. Examples of ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, and methylcyclohexanone. Examples of ethers having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole and phenetole. Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol.

  The alcohol used in combination with the chlorinated organic solvent may preferably be linear, branched or cyclic, and is preferably a saturated aliphatic hydrocarbon. The hydroxyl group of the alcohol may be any of primary to tertiary. Examples of the alcohol include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, t-butanol, 1-pentanol, 2-methyl-2-butanol and cyclohexanol. As the alcohol, fluorine-based alcohol is also used. Examples thereof include 2-fluoroethanol, 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoro-1-propanol and the like. Furthermore, the hydrocarbon may be linear, branched or cyclic. Either aromatic hydrocarbons or aliphatic hydrocarbons can be used. The aliphatic hydrocarbon may be saturated or unsaturated. Examples of hydrocarbons include cyclohexane, hexane, benzene, toluene and xylene.

Examples of combinations of chlorinated organic solvents and other organic solvents include the following compositions, but are not limited thereto.
Dichloromethane / methanol / ethanol / butanol = 80/10/5/5 (parts by mass), dichloromethane / acetone / methanol / propanol = 80/10/5/5 (parts by mass), dichloromethane / methanol / butanol / cyclohexane = 80 / 10/5/5 (parts by mass), dichloromethane / methyl ethyl ketone / methanol / butanol = 80/10/5/5 (parts by mass), dichloromethane / acetone / methyl ethyl ketone / ethanol / isopropanol = 75/8/5/5/7 ( Parts by mass), dichloromethane / cyclopentanone / methanol / isopropanol = 80/7/5/8 (parts by mass) dichloromethane / methyl acetate / butanol = 80/10/10 (parts by mass), dichloromethane / cyclohexanone / methanol / hexane = 70 20/5/5 (parts by mass), dichloromethane / methyl ethyl ketone / acetone / methanol / ethanol = 50/20/20/5/5 (parts by mass), dichloromethane / 1, 3 dioxolane / methanol / ethanol = 70/20/5 / 5 (part by mass), dichloromethane / dioxane / acetone / methanol / ethanol = 60/20/10/5/5 (part by mass), dichloromethane / acetone / cyclopentanone / ethanol / isobutanol / cyclohexane = 65/10 / 10/5/5/5 (parts by mass), dichloromethane / methyl ethyl ketone / acetone / methanol / ethanol = 70/10/10/5/5 (parts by mass), dichloromethane / acetone / ethyl acetate / ethanol / butanol / hexane = 65 / 10/10/5/5/5 (parts by mass), Chloromethane / methyl acetoacetate / methanol / ethanol = 65/20/10/5 (parts by mass), dichloromethane / cyclopentanone / ethanol / butanol = 65/20/10/5 (parts by weight).

[Non-chlorine solvents]
Next, a non-chlorine organic solvent that is preferably used in preparing a cellulose acylate solution that is preferably used in the present invention will be described. In the present invention, the non-chlorine organic solvent is not particularly limited as long as the object can be achieved as long as the cellulose acylate is dissolved and can be cast and formed into a film. The non-chlorine organic solvent used in the present invention is preferably a solvent selected from esters, ketones and ethers having 3 to 12 carbon atoms. Esters, ketones and ethers may have a cyclic structure. A compound having two or more functional groups of esters, ketones and ethers (that is, —O—, —CO— and —COO—) can also be used as a main solvent. It may have a functional group of In the case of the main solvent having two or more kinds of functional groups, the number of carbon atoms may be within the specified range of the compound having any functional group. Examples of esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate. Examples of ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone and methyl acetyl acetate. Examples of ethers having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole and phenetole. Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol.

The above-mentioned non-chlorine organic solvent used for cellulose acylate is selected from the various viewpoints described above, and is preferably as follows.
That is, the non-chlorine solvent is preferably a mixed solvent containing the non-chlorine organic solvent as a main solvent, and is a mixed solvent of three or more different solvents, wherein the first solvent is methyl acetate, ethyl acetate, At least one selected from methyl formate, ethyl formate, acetone, dioxolane, dioxane, or a mixture thereof, the second solvent is selected from ketones having 4 to 7 carbon atoms or acetoacetate, The solvent is a mixed solvent selected from alcohols or hydrocarbons having 1 to 10 carbon atoms, more preferably alcohols having 1 to 8 carbon atoms. Note that when the first solvent is a mixed liquid of two or more kinds of solvents, the second solvent may be omitted. The first solvent is more preferably methyl acetate, acetone, methyl formate, ethyl formate, or a mixture thereof, and the second solvent is preferably methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl acetyl acetate, or a mixture thereof. It may be a solvent.

  The alcohol as the third solvent may have a hydrocarbon chain that is linear, branched, or cyclic, and among them, a saturated aliphatic hydrocarbon chain is preferable. The hydroxyl group of the alcohol may be any of primary to tertiary. Examples of the alcohol include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, t-butanol, 1-pentanol, 2-methyl-2-butanol and cyclohexanol. In addition, as the alcohol, a fluorine-based alcohol in which part or all of the hydrogen in the hydrocarbon chain is substituted with fluorine is also used. Examples thereof include 2-fluoroethanol, 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoro-1-propanol and the like.

  Furthermore, the hydrocarbon may be linear, branched or cyclic. Either aromatic hydrocarbons or aliphatic hydrocarbons can be used. The aliphatic hydrocarbon may be saturated or unsaturated. Examples of hydrocarbons include cyclohexane, hexane, benzene, toluene and xylene.

  These alcohols and hydrocarbons as the third solvent may be used alone or in a mixture of two or more, and are not particularly limited. As the third solvent, preferred specific compounds include alcohol, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and cyclohexanol, and hydrocarbons such as cyclohexane and hexane. Particularly preferred are methanol, ethanol, 1-propanol, 2-propanol and 1-butanol.

  The mixing ratio of the above three types of mixed solvents is that the first solvent is 20 to 95% by mass, the second solvent is 2 to 60% by mass, and the third solvent is 2 to 30% by mass in the total amount of the mixed solvent. %, Preferably the first solvent is 30 to 90% by mass, the second solvent is 3 to 50% by mass, and the third alcohol is 3 to 25% by mass. preferable. In particular, the first solvent is preferably 30 to 90% by mass, the second solvent is preferably 3 to 30% by mass, and the third solvent is an alcohol, and preferably 3 to 15% by mass.

  The non-chlorine-based organic solvent used in the present invention is described in detail on pages 12-16 of the Japan Society for Invention and Innovation Technical Bulletin No. 2001-1745 (issued on March 15, 2001, Japan Society for Invention). Has been.

Preferred combinations of non-chlorine organic solvents of the present invention can include the following, but are not limited thereto.
Methyl acetate / acetone / methanol / ethanol / butanol = 75/10/5/5/5 (parts by mass), methyl acetate / acetone / methanol / ethanol / propanol = 75/10/5/5/5 (parts by mass), Methyl acetate / acetone / methanol / butanol / cyclohexane = 75/10/5/5/5 (part by mass), methyl acetate / acetone / ethanol / butanol = 81/8/7/4 (part by mass), methyl acetate / acetone / Ethanol / butanol = 82/10/4/4 (part by mass), methyl acetate / acetone / ethanol / butanol = 80/10/4/6 (part by mass), methyl acetate / methyl ethyl ketone / methanol / butanol = 80/10 / 5/5 (parts by mass), methyl acetate / acetone / methyl ethyl ketone / ethanol / isopropanol = 5/8/5/5/7 (parts by mass), methyl acetate / cyclopentanone / methanol / isopropanol = 80/7/5/8 (parts by mass), methyl acetate / acetone / butanol = 85/10/5 ( Parts by mass), methyl acetate / cyclopentanone / acetone / methanol / butanol = 60/15/14/5/6 (parts by mass), methyl acetate / cyclohexanone / methanol / hexane = 70/20/5/5 (parts by mass) ), Methyl acetate / methyl ethyl ketone / acetone / methanol / ethanol = 50/20/20/5/5 (part by mass), methyl acetate / 1,3-dioxolane / methanol / ethanol = 70/20/5/5 (part by mass) ), Methyl acetate / dioxane / acetone / methanol / ethanol = 60/20/10/5/5 (parts by mass),
Methyl acetate / acetone / cyclopentanone / ethanol / isobutanol / cyclohexane = 65/10/10/5/5/5 (parts by mass),

Methyl formate / methyl ethyl ketone / acetone / methanol / ethanol = 50/20/20/5/5 (parts by mass), methyl formate / acetone / ethyl acetate / ethanol / butanol / hexane = 65/10/10/5/5/5 (Mass part), acetone / methyl acetoacetate / methanol / ethanol = 65/20/10/5 (mass part), acetone / cyclopentanone / ethanol / butanol = 65/20/10/5 (mass part),
Acetone / 1,3-dioxolane / ethanol / butanol = 65/20/10/5 (parts by mass), 1,3-dioxolane / cyclohexanone / methyl ethyl ketone / methanol / butanol = 55/20/10/5/5/5 ( Part by mass), and the like.

Furthermore, a cellulose acylate solution prepared by the following method can also be used.
A method of preparing a cellulose acylate solution with methyl acetate / acetone / ethanol / butanol = 81/8/7/4 (parts by mass), adding 2 parts by mass of butanol after filtration and concentration,
A method of preparing a cellulose acylate solution with methyl acetate / acetone / ethanol / butanol = 84/10/4/2 (parts by mass), adding 4 parts by mass of butanol after filtration and concentration,
A method of preparing a cellulose acylate solution with methyl acetate / acetone / ethanol = 84/10/6 (parts by mass), adding 5 parts by mass of butanol after filtration and concentration,

  In addition to the non-chlorine organic solvent of the present invention, the dope used in the present invention may contain dichloromethane in an amount of 10% by mass or less of the total amount of organic solvent used in the present invention.

[Characteristics of cellulose acylate solution]
The cellulose acylate solution is a solution in which cellulose acylate is dissolved in the organic solvent, and the concentration thereof is preferably in the range of 10 to 30% by mass from the viewpoint of film-forming casting suitability, more preferably. It is 13-27 mass%, Most preferably, it is 15-25 mass%.
The method for bringing the cellulose acylate solution into such a concentration range may be a predetermined concentration at the stage of dissolution, and will be described later after it is prepared in advance as a low concentration solution (for example, 9 to 14% by mass). You may adjust to a predetermined high concentration solution by a concentration process. Furthermore, after preparing a high concentration cellulose acylate solution in advance, various additives may be added to obtain a predetermined low concentration cellulose acylate solution, and any method is preferably used in the present invention. There is no particular problem if it is carried out so as to have a concentration.

Next, in the present invention, when the cellulose acylate solution is made 0.1 to 5% by mass with an organic solvent having the same composition, the aggregate molecular weight of the cellulose acylate in the diluted solution is 150,000 to 15 million. Is preferable from the viewpoint of solubility in a solvent. The associated molecular weight is more preferably 180,000 to 9 million. This associated molecular weight can be determined by a static light scattering method. In that case, it is preferable to melt | dissolve so that the inertial radius calculated | required simultaneously may be 10-200 nm. A more preferable radius of inertia is 20 to 200 nm. Furthermore, it is preferable to dissolve so that the second virial coefficient is −2 × 10 ⁻⁴ to + 4 × 10 ^−4, and more preferably, the second virial coefficient is −2 × 10 ⁻⁴ to + 2 × 10 ^−4. It is.

  Here, the definition of the associated molecular weight, the radius of inertia, and the second virial coefficient in the present invention will be described. These are measured using the static light scattering method according to the following method. Although the measurement is performed in a dilute region for the convenience of the apparatus, these measured values reflect the behavior of the dope in the high concentration region of the present invention.

  First, cellulose acylate is dissolved in a solvent used for the dope to prepare solutions of 0.1 mass%, 0.2 mass%, 0.3 mass%, and 0.4 mass%. In order to prevent moisture absorption, the cellulose acylate is dried at 120 ° C. for 2 hours, and is measured at 25 ° C. and 10% RH. The dissolution method is carried out according to the method employed at the time of dope dissolution (room temperature dissolution method, cooling dissolution method, high temperature dissolution method). Subsequently, the solution and the solvent are filtered through a 0.2 μm Teflon (registered trademark) filter. Then, static light scattering of the filtered solution is measured at 10 ° intervals from 30 ° to 140 ° at 25 ° C. using a light scattering measuring device “DLS-700” (manufactured by Otsuka Electronics Co., Ltd.). The obtained data is analyzed by the BERRY plot method. The refractive index necessary for this analysis is the value of the solvent determined by the Abbe refractive system, and the refractive index concentration gradient (dn / dc) is a differential refractometer “DRM-1021” {manufactured by Otsuka Electronics Co., Ltd. }, And using the solvent and solution used for the light scattering measurement.

[Preparation of dope]
Next, preparation of a solution (dope) for casting and film formation of cellulose acylate will be described.
The method for dissolving cellulose acylate is not particularly limited, and may be a room temperature dissolution method, a cooling dissolution method or a high temperature dissolution method, or a combination thereof. Regarding these, for example, JP-A-5-163301, JP-A-61-106628, JP-A-58-127737, JP-A-9-95544, JP-A-10-95854, JP-A-10-45950, JP 2000-53784, JP 11-322946, JP 11-322947, JP 2-276830, JP 2000-273239, JP 11-71463, JP 04-259511, Special JP-A-2000-273184, JP-A-11-323017, JP-A-11-302388, and the like describe the methods for preparing a cellulose acylate solution.

  As long as the method for dissolving these cellulose acylates in an organic solvent described in the above publications is within the scope of the present invention, these techniques can also be applied to the present invention. The details of these, particularly the non-chlorine solvent system, are also described in detail in the Invention Association Open Technical Bulletin No. 2001-1745 (issued March 15, 2001, Invention Association), pages 22-25, It can be carried out according to that method. Further, the cellulose acylate dope solution preferably used in the present invention is usually subjected to solution concentration and filtration, and these are similarly applied to the Japan Institute of Invention and Technology Publication No. 2001-1745 (March 2001). (Published on 15th, Invention Association), page 25. In addition, when it melt | dissolves at high temperature, it is the case where it is more than the boiling point of the organic solvent to be used, and in that case, it carries out in a pressurized state.

It is preferable that the cellulose acylate solution has a viscosity and a dynamic storage elastic modulus within the ranges described below because it is easy to cast. These values are measured using 1 mL of the sample solution in a rheometer “CLS 500” and “Steel Cone” (both manufactured by TA Instruments) having a diameter of 4 cm / 2 °. Measurement conditions were measured by varying the range from 40 ° C. to −10 ° C. at 2 ° C./min using Oscillation Step / Temperature Ramp, and static non-Newtonian viscosity n ^* (Pa · s) at 40 ° C. and storage at −5 ° C. The elastic modulus G ′ (Pa) is obtained. The sample solution is kept warm until the liquid temperature becomes constant at the measurement start temperature, and then the measurement is started.

  In the present invention, the viscosity at 40 ° C. is 1 to 400 Pa · s, the dynamic storage elastic modulus at 15 ° C. is preferably 500 Pa or more, and more preferably the viscosity at 40 ° C. is 10 to 200 Pa · s. Therefore, the dynamic storage elastic modulus at 15 ° C. should be 100 to 1,000,000. Furthermore, the dynamic storage elastic modulus at low temperature is preferably as large as possible. For example, when the casting support is −5 ° C., the dynamic storage elastic modulus is preferably 10,000 to 1,000,000 Pa at −5 ° C. When the support is at −50 ° C., the dynamic storage elastic modulus at −50 ° C. is preferably 10,000 to 5 million Pa.

  In the present invention, since the above-mentioned specific cellulose acylate is used, it is characterized in that a high concentration dope can be obtained. A cellulose acylate having a high concentration and excellent stability can be obtained without resorting to a means of concentration. A rate solution is obtained. Further, in order to facilitate dissolution, it may be concentrated using a concentration means after being dissolved at a low concentration. The concentration method is not particularly limited. For example, the low-concentration solution is guided between the cylindrical body and the rotation trajectory of the outer periphery of the rotating blade rotating in the circumferential direction, and the temperature between the solution and the solution. A method of giving a difference and obtaining a high-concentration solution while evaporating the solvent (for example, JP-A-4-259511), until a heated low-concentration solution is blown into the container from the nozzle until the solution hits the inner wall of the container from the nozzle The solvent is flash evaporated between the container and the solvent vapor is withdrawn from the container and the concentrated solution is withdrawn from the container bottom (eg, US Pat. No. 2,541,012, US Pat. No. 2,858,229, US The method described in Japanese Patent No. 4,414,341, US Pat. No. 4,504,355, etc.) and the like.

  Prior to casting, the dope solution is preferably filtered off foreign matters such as undissolved matter, dust, and impurities using an appropriate filter medium such as a wire mesh or flannel. For filtration of the cellulose acylate solution, it is preferable to use a filter having an absolute filtration accuracy of 0.1 to 100 μm, and it is more preferable to use a filter having an absolute filtration accuracy of 0.5 to 25 μm. The thickness of the filter is preferably 0.1 to 10 mm, and more preferably 0.2 to 2 mm. In that case, the filtration pressure is preferably 1.6 MPa or less, more preferably 1.2 MPa or less, further 1.0 MPa or less, and particularly preferably 0.2 MPa or less. As the filter medium, conventionally known materials such as glass fibers, cellulose fibers, filter paper, fluororesins such as tetrafluoroethylene resin can be preferably used, and ceramics, metals and the like are particularly preferably used. The viscosity of the cellulose acylate solution immediately before film formation may be in a range that can be cast during film formation, and is usually prepared in a range of 10 Pa · s to 2000 Pa · s, preferably 30 Pa · s to 1000 Pa. · S is more preferable, and 40 Pa · s to 500 Pa · s is more preferable. The temperature at this time is not particularly limited as long as it is a temperature at the time of casting, but is preferably −5 to + 70 ° C., more preferably −5 to + 55 ° C.

[Film formation]
The optical film preferably used in the present invention can be obtained by forming a film using a solution (dope) such as cellulose acylate. As the film forming method and equipment, a solution casting film forming method and a solution casting film forming apparatus conventionally used for producing a cellulose triacetate film are used. The dope (cellulose acylate solution) prepared from the dissolving machine (kettle) is temporarily stored in a storage kettle, and the foam contained in the dope is defoamed for final preparation. The dope is sent from the dope discharge port to the pressurizing die through a pressurizing quantitative gear pump capable of feeding the dope with high accuracy by the number of rotations, for example, and the dope is run endlessly from the die (slit) of the pressurizing die The dope film (also referred to as a web) is peeled off from the metal support at the peeling point where the metal support is cast almost uniformly around the metal support. The both ends of the obtained web are sandwiched between clips, transported by a tenter while maintaining the width, dried, and then transported by a roll group of a drying device to finish drying, and wound to a predetermined length by a winder. The combination of the tenter and the roll group dryer varies depending on the purpose. In the solution casting film forming method used for the functional protective film for electronic displays, in addition to the solution casting film forming apparatus, surface processing on films such as an undercoat layer, an antistatic layer, an antihalation layer, a protective layer, etc. Therefore, a coating device is often added. Although each manufacturing process is described briefly below, it is not limited to these.

  When producing an optical film such as a cellulose acylate film by the solvent casting method, first, the prepared polymer solution (dope) such as cellulose acylate is cast on a drum or a band, and the solvent is evaporated to form a film. . It is preferable to adjust the concentration of the dope before casting so that the solid content is 5 to 40% by mass. The surface of the drum or band is preferably finished in a mirror state. For the dope, a method of casting on a drum or band having a surface temperature of 30 ° C. or less is preferably employed, and the metal support temperature is particularly preferably in the range of −10 to 20 ° C. Further, in the present invention, JP-A Nos. 2000-301555, 2000-301558, 07-032391, JP-A-03-193316, JP-A-05-086212, JP-A-62-037113, The methods described in JP-A No. 02-276607, JP-A No. 55-014201, JP-A No. 02-111511, and JP-A No. 02-208650 can be used.

[Multilayer casting]
The polymer solution such as cellulose acylate may be cast as a single-layer liquid on a smooth band or drum as a metal support, or a plurality of polymer liquids such as cellulose acylate of two or more layers may be cast. Also good. When casting a plurality of polymer solutions such as cellulose acylate, a solution containing a polymer such as cellulose acylate is cast from a plurality of casting openings provided at intervals in the traveling direction of the metal support, and laminated. For example, the methods described in JP-A-61-158414, JP-A-1-122419, and JP-A-11-198285 can be applied. Further, it can be formed into a film by casting a polymer solution such as cellulose acylate from two casting ports. For example, JP-B-60-27562, JP-A-61-94724, JP-A-61-947245. The methods described in JP-A-61-104813, JP-A-61-158413, and JP-A-6-134933 can be carried out. Furthermore, the flow of a polymer solution such as cellulose acylate having a high viscosity described in JP-A-56-162617 is wrapped with a polymer solution such as cellulose acylate having a low viscosity, and the polymer solution having a high viscosity and a low viscosity such as cellulose acylate May be simultaneously extruded, and an optical film casting method such as a cellulose acylate film may be used. Furthermore, as described in JP-A-61-94724 and JP-A-61-94725, it is also preferable that the outer solution contains a larger amount of an alcohol component that is a poor solvent than the inner solution. . Alternatively, two casting ports are used, and after the film formed on the metal support is peeled off by the first casting port, the second casting is performed on the side of the film that is in contact with the metal support surface. Thus, a film having a plurality of layers can also be produced, and examples thereof include a method described in Japanese Patent Publication No. 44-20235. The polymer solutions such as cellulose acylate to be cast may be the same solution or different polymer solutions such as cellulose acylate, and are not particularly limited. In order to give a function to a plurality of polymer layers such as cellulose acylate, a polymer solution such as cellulose acylate corresponding to the function may be extruded from each casting port. Furthermore, a polymer solution such as cellulose acylate can be cast simultaneously with other functional layers (for example, an adhesive layer, a dye layer, an antistatic layer, an antihalation layer, a UV absorbing layer, a polarizing layer, etc.).

  In order to obtain the required film thickness in the conventional monolayer liquid, it is necessary to extrude a polymer solution such as cellulose acylate having a high concentration and high viscosity. In this case, the stability of the polymer solution such as cellulose acylate is required. In many cases, a solid matter is generated, which is likely to be worsened, resulting in a failure or flatness. As a solution to this problem, it is possible to extrude a high viscosity solution onto a metal support at the same time by casting a plurality of polymer solutions such as cellulose acylate from a plurality of casting ports relatively little by little. In addition, not only can a flat film with improved flatness be produced, but also the use of a dense polymer solution such as cellulose acylate can reduce the drying load and increase the production speed of the film. .

  In the case of co-casting, the inner and outer thicknesses are not particularly limited, but preferably the outer side is preferably 1 to 50% of the total film thickness, and more preferably 2 to 30%. Here, in the case of co-casting of three or more layers, the total film thickness of the layer in contact with the metal support and the layer in contact with the air side is defined as the outer thickness. In the case of co-casting, an optical film such as a cellulose acylate film having a laminated structure is produced by co-casting a polymer solution such as cellulose acylate having a different additive concentration such as the plasticizer, ultraviolet absorber, or matting agent. You can also. For example, an optical film such as a cellulose acylate film having a structure of skin layer / core layer / skin layer can be produced. For example, the matting agent can be contained in the skin layer in a large amount or only in the skin layer. The plasticizer and the ultraviolet absorber can be contained in the core layer more than the skin layer, and may be contained only in the core layer. It is also possible to change the type of plasticizer and ultraviolet absorber between the core layer and the skin layer. For example, the skin layer contains at least one of a low-volatile plasticizer and an ultraviolet absorber, and the core layer has excellent plasticity. It is also possible to add a plasticizer or an ultraviolet absorber excellent in ultraviolet absorption. Furthermore, it is also a preferred embodiment that a peeling accelerator is contained only in the skin layer on the metal support side. Furthermore, it is also preferable to add more alcohol, which is a poor solvent, to the skin layer than the core layer in order to cool the metal support by the cooling drum method to gel the solution. The Tg of the skin layer and the core layer may be different, and the Tg of the core layer is preferably lower than the Tg of the skin layer. Furthermore, the viscosity of the solution containing a polymer such as cellulose acylate during casting may be different between the skin layer and the core layer, and the viscosity of the skin layer is preferably smaller than the viscosity of the core layer. May be smaller than the viscosity of the skin layer.

[Casting method]
As a solution casting method, a method in which the prepared dope is uniformly extruded from a pressure die onto a metal support, and a method using a doctor blade in which the dope once cast on the metal support is adjusted with a blade is used. Although there is a method using a reverse roll coater that adjusts with a reverse rotating roll, a method using a pressure die is preferred. The pressure die includes a coat hanger type and a T die type, and any of them can be preferably used. In addition to the methods mentioned here, it can be carried out by various known methods for casting a cellulose triacetate solution, and each condition is set in consideration of differences in the boiling point of the solvent used. Thus, the same effects as those described in the respective publications can be obtained.

  As an endlessly running metal support used for producing an optical film such as a cellulose acylate film preferably used in the present invention, a drum whose surface is mirror-finished by chrome plating or mirror-finished by surface polishing A stainless steel belt (which may be called a band) is used. One or more pressure dies may be installed above the metal support. Preferably 1 or 2 groups. When two or more are installed, the amount of dope to be cast may be divided into various ratios for each die, or the dope may be fed to the dies from each of a plurality of precision quantitative gear pumps. The temperature of the polymer solution such as cellulose acylate used for casting is preferably −10 to 55 ° C., more preferably 25 to 50 ° C. In that case, all solution temperatures in the process may be the same or different at different points in the process. If they are different, the temperature may be a desired temperature just before casting.

[Dry]
The dope drying on the metal support, which is involved in the production of an optical film such as a cellulose acylate film, is generally performed from the surface side of the metal support (drum or belt), that is, from the surface of the web on the metal support. A method in which hot air is applied, a method in which hot air is applied from the back surface of the drum or belt, a temperature-controlled liquid is brought into contact with the back surface on the opposite side of the belt or drum dope casting surface, and the drum or belt is heated by heat transfer to heat the surface. Although there is a back surface liquid heat transfer method for controlling the temperature, the back surface liquid heat transfer method is preferable. The surface temperature of the metal support before casting may be any number as long as it is not higher than the boiling point of the solvent used for the dope. However, in order to promote drying and to lose fluidity on the metal support, the temperature should be set to 1 to 10 ° C. lower than the boiling point of the lowest boiling solvent. Is preferred. This is not the case when the cast dope is cooled and peeled off without drying.

  In order to suppress light leakage when the polarizing plate is viewed obliquely, it is necessary to arrange the transmission axis of the polarizer and the in-plane slow axis of an optical film such as a cellulose acylate film in parallel. Since the transmission axis of the roll film polarizer produced continuously is generally parallel to the width direction of the roll film, the optical film such as the roll film polarizer and the roll film cellulose acylate film is used. In order to continuously bond a protective film made of a film, the in-plane slow axis of the roll film-shaped protective film needs to be parallel to the width direction of the film. Therefore, it is preferable to stretch more in the width direction. The stretching process may be performed in the middle of the film forming process, or the original fabric that has been formed and wound may be stretched. In the former case, stretching may be performed in a state containing a residual solvent, and the stretching can be preferably performed at a residual solvent amount of 2 to 30% by mass.

  The film thickness of the optical film such as cellulose acylate film preferably used in the present invention obtained after drying varies depending on the purpose of use, and is usually preferably in the range of 5 to 500 μm, more preferably in the range of 20 to 300 μm. The range of 30 to 150 μm is particularly preferable. Moreover, it is preferable that it is 40-110 micrometers for optical use, especially for VA liquid crystal display devices. The film thickness may be adjusted by adjusting the solid content concentration contained in the dope, the slit gap of the die base, the extrusion pressure from the die, the metal support speed, and the like so as to obtain a desired thickness.

[Stretching treatment]
The optical film of the present invention is preferably stretched. The orientation of the retardation developer can be effectively controlled by the stretching treatment, and a desired retardation can be imparted to the film. The stretching direction of the film is preferably either the width direction or the longitudinal direction.

  Methods for stretching in the width direction are described in, for example, JP-A-62-115035, JP-A-4-152125, JP-A-2842211, JP-A-298310, and JP-A-11-48271. Yes.

  The stretching temperature of the film is preferably (Tg-10 ° C) or more and (Tg + 60 ° C) or less, more preferably (Tg + 10 ° C) or more (Tg + 40 ° C or less).

  Further, when the retardation developing agent is a liquid crystalline compound, the film is stretched at a temperature higher than the crystal-liquid crystal transition temperature of the retardation developing agent, and the film is held at a constant stretching ratio until the temperature becomes lower than the liquid crystal-crystal transition temperature. It is preferable to maintain such stress. By stretching the film under the above conditions, it is possible to increase the degree of orientation of the retardation developer and to obtain high retardation expression efficiency.

  In the case of stretching in the longitudinal direction, for example, the film is stretched by adjusting the speed of the film transport roller so that the film winding speed is higher than the film peeling speed. In the case of stretching in the width direction, the film can also be stretched by conveying while holding the width of the film with a tenter and gradually widening the width of the tenter. After the film is dried, it can be stretched using a stretching machine (preferably uniaxial stretching using a long stretching machine).

  In the present invention, in particular, a method for producing an optical film such as cellulose acylate, or a film comprising a stretching step of stretching in the film transport direction and a shrinking step of shrinking while gripping the film in the width direction of the film A method for producing an optical film such as cellulose acylate, which includes a stretching step of stretching in the width direction of the film and a shrinking step of contracting in the film transport direction, is preferably used.

First, a method for producing an optical film such as cellulose acylate, which includes a stretching step of stretching in the film transport direction and a shrinking step of shrinking while gripping the film in the width direction of the film will be described.
In this case, the film is stretched in the film transport direction. However, as a method of stretching in the film transport direction, the speed of the film transport roller is adjusted to adjust the speed of the film transport roller, and the film is wound more than the film peeling speed. A method of increasing the speed is preferably used.
In this case, the film can be contracted substantially perpendicular to the stretching direction by conveying the film while holding the film with a tenter and gradually reducing the width of the tenter.

  Specifically, it is held by a chain-type, screw-type, pantograph-type, linear motor-type tenter, etc., and while stretching in the transport direction, the film is stretched by gradually narrowing the width of the tenter and simultaneously in the orthogonal direction. Can shrink.

  On the other hand, a chain type, screw type, pantograph type, linear motor in a method for producing a polymer such as cellulose acylate, characterized in that it includes a stretching step for stretching in the width direction of the film and a shrinking step for contracting in the film conveyance direction. The film can be contracted by holding it by a formula or the like and gradually narrowing the interval between the clips in the conveying direction while stretching in the width direction of the film.

  In the method described above, it can be said that at least a part of the stretching step and the shrinking step are performed simultaneously.

  In addition, Ichikin Kogyo Co., Ltd. is a stretching apparatus that specifically performs a stretching process that stretches either the longitudinal direction or the width direction of the film as described above, simultaneously shrinks the other, and simultaneously increases the film thickness of the film. A company-made FITZ machine or the like can be desirably used. This apparatus is described in (Japanese Patent Laid-Open No. 2001-38802).

  The stretching ratio in the stretching process and the shrinking ratio in the shrinking process can be arbitrarily selected depending on the values of the desired front retardation Re and retardation Rth in the film thickness direction. Is preferably 10% or more, and the shrinkage rate in the shrinking step is preferably 5% or more.

  In addition, the stretch rate as used in the field of this invention means the ratio of the length of the film after extending | stretching with respect to the length of the film before extending | stretching in a extending direction, and a shrinkage rate is the film before shrinking | contracting in a shrinking direction. It means the ratio of the contracted length of the film after contraction to the length.

  The stretching ratio is preferably 3 to 200%, more preferably 10 to 100%, and particularly preferably 15 to 45%. On the other hand, the shrinkage is preferably 5 to 40%, particularly preferably 10 to 30%.

  The treatment temperature is the film surface temperature measured with a non-contact infrared thermometer.

  After the film is dried, it can be stretched using a stretching machine (preferably uniaxial stretching using a long stretching machine). In addition, the stretching may be performed in one stage or in multiple stages. When performing in multiple stages, the product of each draw ratio may be in this range.

  The stretching speed is preferably 5% / min to 1000% / min, and more preferably 10% / min to 500% / min. The stretching is preferably performed by a heat roll or / and a radiant heat source (such as an IR heater) or warm air. Moreover, you may provide a thermostat in order to improve the uniformity of temperature. When performing uniaxial stretching by roll stretching, it is preferable that L / W which is a ratio of distance between rolls (L) and film width (W) is 2.0 to 5.0.

  The width of the optical film such as a cellulose acylate film obtained as described above is preferably 0.5 to 3 m, more preferably 0.6 to 2.5 m, still more preferably 0.8 to 2.2 m. is there. The length is preferably 100 to 10,000 m per roll, more preferably 500 to 7000 m, and still more preferably 1000 to 6000 m. When winding, it is preferable to give knurling to at least one end, the knurling width is preferably 3 mm to 50 mm, more preferably 5 mm to 30 mm, and the height is preferably 0.5 to 500 μm, more preferably 1 to 200 μm. is there. This may be a single push or a double push.

The variation in the Re (590) value in the width direction of the film is preferably ± 5 nm, and more preferably ± 3 nm. The variation of Rth ₅₉₀ value in the width direction is ± 10 nm.
Is preferable, and more preferably ± 5 nm. Moreover, it is preferable that the variation in the Re value and the Rth value in the length direction is also within the range of the variation in the width direction.

  The variation of the slow axis angle in the film plane of the optical film such as a cellulose acylate film preferably used in the present invention is preferably in the range of −2 ° to + 2 ° with respect to the reference direction of the roll film, More preferably, it is in the range of -1 ° to + 1 °, and most preferably in the range of -0.5 ° to + 0.5 °. Here, the reference direction is the longitudinal direction of the roll film when the cellulose acylate film is longitudinally stretched, and the width direction of the roll film when laterally stretched.

Further, an optical film such as a cellulose acylate film preferably used in the present invention has a difference ΔRe (= Re _10% −Re ₈₀₎ between the Re value at 25 ° C. and 10% RH and the Re value at 25 ° C. and 80% RH. _% ) Is 0 to 10 nm, and the difference ΔRth (= Rth _10% −Rth _80% ) between the Rth value at 25 ° C. and 10% RH and the Rth value at 25 ° C. and 80% RH is 0 to 30 nm. However, it is preferable in order to reduce the color change with time of the liquid crystal display device.

Furthermore, an optical film such as a cellulose acylate film preferably used in the present invention has an equilibrium water content of not more than 3.2% at 25 ° C. and 80% RH, which reduces the change in color of the liquid crystal display device over time. Preferred above.
The moisture content is measured using a 7 mm × 35 mm optical film sample such as a cellulose acylate film, a moisture measuring device and a sample drying apparatus {“CA-03”, “VA-05”, both Mitsubishi Chemical Corporation}}. And then measured by the Karl Fischer method. It is calculated by dividing the amount of water (g) by the sample mass (g).

Furthermore, an optical film such as a cellulose acylate film preferably used in the present invention has a moisture permeability of 60 ° C., 95% RH, and 24 hours (in terms of a film thickness of 80 μm) of 400 g / m ² · 24 hr to 1800 g / m ^2. -It is preferable that it is 24 hours or less in order to reduce the color change with time of a liquid crystal display device.

The moisture permeability decreases as the film thickness of an optical film such as a cellulose acylate film increases, and increases as the film thickness decreases. Therefore, it is necessary to provide and convert a reference film thickness in any film thickness sample. In the present invention, the film thickness was converted according to the following formula (13) with the standard film thickness set to 80 μm.
Formula (13):
Moisture permeability in terms of 80 μm = measured moisture permeability × measured film thickness μm / 80 μm.

  The measurement method of moisture permeability is "Polymer Physical Properties II" (Polymer Experiment Course 4, Kyoritsu Shuppan), pages 285-294: Measurement of vapor permeation (mass method, thermometer method, vapor pressure method, adsorption amount method) The method described in can be applied.

  The glass transition temperature was measured after conditioning an optical film sample (unstretched) 5 mm × 30 mm such as a cellulose acylate film at 25 ° C. and 60% RH for 2 hours or more, and then measuring the dynamic viscoelasticity measuring device “Vibron: DVA”. -225 "{manufactured by IT Measurement Control Co., Ltd.}}, the distance between the grips is 20 mm, the heating rate is 2 ° C./minute, the measurement temperature range is 30 ° C. to 200 ° C., and the frequency is 1 Hz. When the storage elastic modulus is taken on the axis and the temperature (° C) is taken on the linear axis on the horizontal axis, the temperature that shows a sharp decrease in the storage elastic modulus that is observed when the storage elastic modulus moves from the solid region to the glass transition region. The glass transition temperature Tg was used. Specifically, on the obtained chart, when the straight line 1 is drawn in the solid region and the straight line 2 is drawn in the glass transition region, the intersection of the straight line 1 and the straight line 2 decreases rapidly when the temperature rises. The glass transition temperature Tg (dynamic viscoelasticity) was determined because the film started to soften and the temperature started to shift to the glass transition region.

  The elastic modulus was measured by adjusting an optical film sample such as a cellulose acylate film 10 mm × 150 mm at 25 ° C. and 60% RH for 2 hours or more, and then a tensile tester “Strograph-R2” {Toyo Seiki Co., Ltd. Manufactured by Seisakusho}} at a distance between chucks of 100 mm, a temperature of 25 ° C., and a stretching speed of 10 mm / min.

The measurement of the hygroscopic expansion coefficient is a value L _{80% obtained} by measuring the dimension of a film left at 25 ° C. and 80% RH for 2 hours or more with a pin gauge, and the dimension of a film left at 25 ° C. and 10% RH for 2 hours or more. Was obtained by the following formula (14) from the value L _10% measured with a pin gauge.
Formula (14): (L _80% -L _10% ) / (80% RH-10% RH) × 10 ⁶

Moreover, it is preferable that the haze of the optical film such as a cellulose acylate film preferably used in the present invention is in the range of 0.01 to 2%. Here, the haze can be measured as follows.
The haze is measured according to JIS K-6714 using a haze meter “HGM-2DP” (manufactured by Suga Test Instruments Co., Ltd.) at 25 ° C. and 60% RH with an optical film sample such as cellulose acylate film 40 mm × 80 mm .

  Further, the optical film such as a cellulose acylate film preferably used in the present invention preferably has a mass change in the range of 0 to 5% by mass when left at 80 ° C. and 90% RH for 48 hours. .

  Furthermore, an optical film such as a cellulose acylate film preferably used in the present invention is a dimensional change when left for 24 hours under conditions of 60 ° C. and 95% RH, and a condition of 90 ° C. and 5% RH. It is preferable that the dimensional change when left still for 24 hours is in the range of 0 to 5%.

The photoelastic coefficient is preferably 50 × 10 ⁻¹³ cm ² / dyn (50 × 10 ⁻⁸ cm ² / N) or less in order to reduce the color change with time of the liquid crystal display device.
As a specific measuring method, an optical film sample such as a cellulose acylate film is applied with a tensile stress in the major axis direction of 10 mm × 100 mm, and the retardation at that time is an ellipsometer such as “M150” {JASCO Corporation )} And the photoelastic coefficient is calculated from the amount of change in retardation with respect to stress.

[Melting film formation]
The method for producing the optical film of the present invention may be melt film formation. A raw material such as a polymer or an additive as a raw material may be heated and melted, and may be extruded and formed into a film by injection molding. Alternatively, the raw material may be sandwiched between two heated plates and pressed to form a film.

  The temperature for heating and melting is not particularly limited as long as the raw polymer is melted uniformly. Specifically, it is heated to a temperature equal to or higher than the melting point or softening point. In order to obtain a uniform film, the material is melted by heating to a temperature higher than the melting point of the starting polymer, preferably 5 to 40 ° C. higher than the melting point, particularly preferably 8 to 30 ° C. higher than the melting point. preferable.

[Alignment film]
The optical compensation film may have an alignment film between the cellulose acylate film of the present invention and the optically anisotropic layer. In addition, the alignment film is used only when the optically anisotropic layer is prepared, and after the optically anisotropic layer is formed on the alignment film, only the optically anisotropic layer is formed on the cellulose acylate film of the present invention. You may transcribe.
In the present invention, the alignment film is preferably a layer made of a crosslinked polymer. The polymer used for the alignment film may be either a polymer that can be crosslinked by itself or a polymer that is crosslinked by a crosslinking agent. The alignment film is formed by reacting a polymer having a functional group or a polymer having a functional group introduced therein with light, heat, pH change, or the like; or a cross-linking agent that is a highly reactive compound Can be formed by introducing a linking group derived from a cross-linking agent between polymers to cross-link between the polymers.

  The alignment film made of a crosslinked polymer can be usually formed by applying a coating solution containing the polymer or a mixture of the polymer and a crosslinking agent on a support, followed by heating. In the rubbing process described later, it is preferable to increase the degree of crosslinking in order to suppress the dust generation of the alignment film. A value (1- (Ma / Mb)) obtained by subtracting 1 from the ratio (Ma / Mb) of the amount (Ma) of the crosslinking agent remaining after crosslinking to the amount (Mb) of the crosslinking agent added to the coating solution. When Mb)) is defined as the degree of crosslinking, the degree of crosslinking is preferably 50% to 100%, more preferably 65% to 100%, and most preferably 75% to 100%.

In the present invention, the polymer used for the alignment film may be either a polymer that can be crosslinked by itself or a polymer that is crosslinked by a crosslinking agent. Of course, a polymer having both functions can also be used. Examples of the polymer include polymethyl methacrylate, acrylic acid / methacrylic acid copolymer, styrene / maleimide copolymer, polyvinyl alcohol and modified polyvinyl alcohol, poly (N-methylolacrylamide), styrene / vinyl toluene copolymer. Chlorosulfonated polyethylene, nitrocellulose, polyvinyl chloride, chlorinated polyolefin, polyester, polyimide, vinyl acetate / vinyl chloride copolymer, ethylene / vinyl acetate copolymer, carboxymethyl cellulose, gelatin, polyethylene, polypropylene, polycarbonate, etc. Examples thereof include compounds such as polymers and silane coupling agents. Examples of preferred polymers are water-soluble polymers such as poly (N-methylolacrylamide), carboxymethylcellulose, gelatin, polyville alcohol, and modified polyvinyl alcohol, and gelatin, polyville alcohol, and modified polyvinyl alcohol are preferred. Mention may be made of bil alcohol and modified polyvinyl alcohol.
In the case of directly coating polyvinyl alcohol and modified polyvinyl alcohol on the cellulose acylate film of the present invention, a method of providing a hydrophilic undercoat layer or applying a saponification treatment is preferably used.

Among the above polymers, polyvinyl alcohol or modified polyvinyl alcohol is preferable.
Examples of the polyvinyl alcohol include those having a saponification degree of 70 to 100%, generally those having a saponification degree of 80 to 100%, and more preferably those having a saponification degree of 82 to 98%. The polymerization degree is preferably in the range of 100 to 3000.
Examples of the modified polyvinyl alcohol include those modified by copolymerization (modified groups such as COONa, Si (OX) ₃ , N (CH ₃ ) ₃ .Cl, C ₉ H ₁₉ COO, SO ₃ Na, C ₁₂ H _25, etc. Modified by chain transfer (for example, COONa, SH, SC ₁₂ H ₂₅ etc. are introduced as modifying groups), modified by block polymerization (modified groups such as COOH, for example) , CONH ₂ , COOR (wherein R is an alkyl group having 12 or less carbon atoms, C ₆ H ₅ or the like is introduced). As a polymerization degree, the range of 100-3000 is preferable. Among these, unmodified or modified polyvinyl alcohol having a saponification degree of 80 to 100% is preferable, and unmodified or alkylthio-modified polyvinyl alcohol having a saponification degree of 85 to 95% is more preferable.
The polyvinyl alcohol is preferably introduced with a crosslinking / polymerization active group in order to provide adhesion between an optical film such as a cellulose acylate film and an optically anisotropic layer. This is described in detail in Japanese Patent No. 8-338913.
When using a hydrophilic polymer such as polyvinyl alcohol for the alignment film, it is preferable to control the moisture content from the viewpoint of the degree of hardening, preferably 0.4% to 2.5%, 0.6% More preferably, it is -1.6%. The water content can be measured with a commercially available Karl Fischer moisture content measuring device.
The alignment film preferably has a thickness of 10 microns or less.

[Polarizer]
The present invention provides a polarizing plate comprising a polarizing film and a pair of protections sandwiching the polarizing film, wherein at least one of the protective films includes the optical film. For example, a polarizing film obtained by dyeing a polarizing film made of a polyvinyl alcohol film or the like with iodine, stretching, and laminating both surfaces with a protective film can be used. The polarizing plate is disposed outside the liquid crystal cell. It is preferable that a pair of polarizing plates each including a polarizing film and a pair of protective films sandwiching the polarizing film are disposed with the liquid crystal cell interposed therebetween. In addition, it is preferable that the protective film arrange | positioned at the liquid crystal cell side is the optical film or cellulose acylate film of this invention.

  The present invention also relates to a polarizer and a polarizing plate having the optical film of the present invention on one side of the polarizer. Similar to the optical film of the present invention, the polarizing plate of the present invention is not limited to the polarizing plate in the form of a film piece cut into a size that can be incorporated into a liquid crystal display device as it is, but is long by continuous production. The polarizing plate of the aspect (for example, roll length 2500m or 3900m or more) rolled into the shape of a roll and rolled up is also contained. In order to use for a large-screen liquid crystal display device, as described above, the width of the polarizing plate is preferably 1470 mm or more.

The polarizing plate of this invention can be used also in the aspect shown to Fig.1 (a) and (b).
In FIG. 1A, a protective film 16 is provided on one surface of a polarizer 11, the optical film of the present invention is disposed as a protective film 14 on the other surface, and an optical anisotropic layer 15 is further provided thereon. Is. The optically anisotropic layer 15 preferably has optical anisotropy that satisfies the expressions (10) and (11) described later.
When this polarizing plate is incorporated in a liquid crystal display device, the optical film and the optically anisotropic layer 15 of the present invention are preferably arranged on the liquid crystal cell side.

Since the protective film 16 is disposed outside, it is preferable in terms of durability to use a low moisture-permeable material. Specifically, it is preferable to use a film having a moisture permeability of 200 g / (m ² · day) or less, more preferably a film of 50 g / (m ² · day) or less, and 20 g / (m ² · day). It is more preferable to use the following film. The lower limit value of the moisture permeability is not particularly limited, but generally, the moisture permeability of the film is about 10 g / (m ² · day). Here, the film moisture permeability indicates a value measured at 40 ° C. and 60% RH. Details are described in JIS0208. As the protective film exhibiting such characteristics, a norbornene-based polymer film is preferable, and a commercially available ZEONOR film or the like can be used. In addition, a low moisture permeability material in which a low moisture permeability coating layer (sometimes referred to as a barrier layer) is provided on a film substrate can also be preferably used. Examples of the coating layer include a polymer containing a repeating unit derived from a chlorine-containing vinyl monomer (hereinafter also referred to as a chlorine-containing polymer). In general, examples of the chlorine-containing vinyl monomer include vinyl chloride and vinylidene chloride. The chlorine-containing polymer can be obtained by copolymerizing these vinyl chloride or vinylidene chloride monomers with a monomer copolymerizable therewith. Further, this chlorine-containing vinyl monomer and other monomers can be copolymerized. Monomers copolymerizable with chlorine-containing vinyl monomers include olefins, styrenes, acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, itaconic acid diesters, maleic acid esters, Selected from fumaric acid diesters, N-alkylmaleimides, maleic anhydride, acrylonitrile, vinyl ethers, vinyl esters, vinyl ketones, vinyl heterocycles, glycidyl esters, unsaturated nitriles, unsaturated carboxylic acids, etc. Monomer.

Note that, for the reason that a film with low moisture permeability is used on the outside of the liquid crystal display device to prevent the ingress of humidity, or that the film with low moisture permeability has low adhesion to the polarizer, FIG. As shown, a protective film 16 ′ may be separately disposed between the polarizer 11 and the low moisture-permeable protective film 16. As the protective film 16 ′, a cellulose acylate film is preferable. In this case, as an example of the present invention, a low moisture permeability film in which the cellulose acylate film is used as the protective film 16 ′ and the above-described chlorine-containing polymer is used as the protective film 16 can be preferably used.
In addition, although the protective film which has a function which protects a polarizer separately may be arrange | positioned between the polarizer 11 and the protective film 14, retardation is prevented so that this protective film may not reduce optical compensation ability. It is preferable to use a film that is substantially zero, such as a cellulose acylate film described in JP-A-2005-138375.

"adhesive"
The adhesive between the polarizing film and the protective film is not particularly limited, and examples thereof include PVA resins (including modified PVA such as acetoacetyl group, sulfonic acid group, carboxyl group, and oxyalkylene group) and boron compound aqueous solution. PVA resin is preferable. The thickness of the adhesive layer is preferably 0.01 to 10 microns after drying, and particularly preferably 0.05 to 5 microns.

《Integrated manufacturing process of polarizing film and protective film》
A polarizing plate that can be used in the present invention can be produced by having a drying process in which a polarizing film is stretched and then contracted to reduce the volatile content, and a protective film is applied to at least one surface after drying or during drying. After combining, it is preferable to have a post-heating step. As a specific attaching method, a protective film is attached to the polarizing film with an adhesive while holding both ends during the drying process of the film, and then both ends are cut off, or after drying, polarized from the holding parts on both ends. There is a method in which the film for film is released, both ends of the film are cut off, and then a protective film is applied. As a method for cutting off the ears, general techniques such as a method of cutting with a cutter such as a blade or a method of using a laser can be used. After bonding, it is preferable to heat in order to dry the adhesive and improve the polarization performance. The heating condition varies depending on the adhesive, but in the case of an aqueous system, it is preferably 30 ° C. or higher, more preferably 40 ° C. to 100 ° C., and further preferably 50 ° C. to 90 ° C. It is more preferable in terms of performance and production efficiency that these processes are manufactured in a consistent line.

<Performance of polarizing plate>
The optical properties and durability (short-term, long-term storage stability) of the polarizing plate of the present invention may be equivalent to or better than commercially available super high contrast products (for example, HLC2-5618 manufactured by Sanlitz Co., Ltd.). preferable. Specifically, the visible light transmittance is 42.5% or more, and the degree of polarization {(Tp−Tc) / (Tp + Tc)} 1/2 ≧ 0.9995 (where Tp is parallel transmittance and Tc is orthogonal transmission) The rate of change in light transmittance before and after standing in an atmosphere of 60 ° C. and a humidity of 90% RH for 500 hours and 80 ° C. in a dry atmosphere for 500 hours is 3% or less based on the absolute value, Further, it is preferably 1% or less, and the rate of change in polarization degree is preferably 1% or less, more preferably 0.1% or less, based on the absolute value.

[Surface treatment of cellulose acylate film]
The cellulose acylate film preferably used in the present invention can achieve improved adhesion between the cellulose acylate film and each functional layer (for example, the undercoat layer and the back layer) by optionally performing a surface treatment. it can. As the surface treatment, for example, glow discharge treatment, ultraviolet irradiation treatment, corona treatment, flame treatment, acid or alkali treatment can be used. The glow discharge treatment here may be low-temperature plasma that occurs under a low pressure gas of 10 ^{−3 to} 20 Torr, and plasma treatment under atmospheric pressure is also preferred. A plasma-excitable gas is a gas that is plasma-excited under the above conditions, and includes chlorofluorocarbons such as argon, helium, neon, krypton, xenon, nitrogen, carbon dioxide, tetrafluoromethane, and mixtures thereof. It is done. Details of these are described in detail on pages 30-32 of the Japan Society for Invention and Innovation Technical Bulletin No. 2001-1745 (issued on March 15, 2001, Japan Institute of Invention). In the plasma treatment at atmospheric pressure, which has been attracting attention in recent years, for example, irradiation energy of 20 to 500 kGy is used under 10 to 1000 keV, more preferably irradiation energy of 20 to 300 kGy is used under 30 to 500 keV. Among these, an alkali saponification treatment is particularly preferable, and it is extremely effective as a surface treatment of a cellulose acylate film.

[Alkaline saponification]
The alkali saponification treatment is preferably carried out by a method in which the cellulose acylate film is directly immersed in a saponification solution tank or a method in which the saponification solution is applied to the cellulose acylate film. Examples of the coating method include a dip coating method, a curtain coating method, an extrusion coating method, a bar coating method, and an E-type coating method. The solvent of the alkali saponification coating solution has good wettability in order to apply the saponification solution to the cellulose acylate film, and the surface of the cellulose acylate film surface is not formed by the saponification solution solvent without forming irregularities. It is preferred to select a solvent that remains good. Specifically, an alcohol solvent is preferable, and isopropyl alcohol is particularly preferable. An aqueous solution of a surfactant can also be used as a solvent. The alkali of the alkali saponification coating solution is preferably an alkali that dissolves in the above solvent, and more preferably KOH or NaOH. The pH of the saponification coating solution is preferably 10 or more, more preferably 12 or more. The reaction conditions during alkali saponification are preferably 1 second to 5 minutes at room temperature, more preferably 5 seconds to 5 minutes, and particularly preferably 20 seconds to 3 minutes. After the alkali saponification reaction, it is preferable to wash the surface on which the saponification solution is applied with water or with an acid and then with water.

Moreover, it is preferable that the polarizing plate regarding this invention provides an optically anisotropic layer on a protective film.
The material of the optically anisotropic layer is not limited, such as a liquid crystal compound, a non-liquid crystal compound, an inorganic compound, and an organic / inorganic composite compound. As the liquid crystalline compound, a low molecular compound having a polymerizable group is aligned, and then the alignment is fixed by polymerization by light or heat, or the liquid crystalline polymer is heated and aligned and then cooled and aligned in a glassy state. You can use what you want to fix. As the liquid crystalline compound, those having a disk-like structure, those having a rod-like structure, and those having a structure showing optical biaxiality can be used. As the non-liquid crystalline compound, a polymer having an aromatic ring such as polyimide or polyester can be used.
Various methods, such as application | coating, vapor deposition, sputtering, can be used for the formation method of an optically anisotropic layer.
When an optically anisotropic layer is provided on the protective film of the polarizing plate, the adhesive layer is further provided outside the optically anisotropic layer from the polarizer side.

  Furthermore, the polarizing plate according to the present invention is preferably one in which at least one layer of a hard coat layer, an antiglare layer or an antireflection layer is provided on the surface of the protective film on at least one side of the polarizing plate. That is, when the polarizing plate is used for a liquid crystal display device, a functional film such as an antireflection layer is preferably provided on the protective film disposed on the side opposite to the liquid crystal cell. Is preferably provided with at least one of a hard coat layer, an antiglare layer or an antireflection layer. In addition, it is not necessary to provide each layer as a separate layer, for example, by providing an antireflection layer and a hard coat layer with an antiglare function, instead of providing two layers of an antireflection layer and an antiglare layer, You may make it function as an anti-glare antireflection layer.

(Antireflection layer)
In the present invention, at least a light scattering layer and a low refractive index layer are laminated in this order on the protective film of the polarizing plate, or a medium refractive index layer, a high refractive index layer, and a low refractive index on the protective film. An antireflection layer in which rate layers are laminated in this order is suitably provided. Preferred examples thereof are described below. In the former configuration, the specular reflectance is generally 1% or more, which is referred to as a low reflection (LR) film. In the latter configuration, it is possible to realize a mirror reflectivity of 0.5% or less, which is called an anti-reflection (AR) film.

[LR film]
A preferred example of an antireflection layer (LR film) in which a light scattering layer and a low refractive index layer are provided on a protective film of a polarizing plate will be described.
In the light scattering layer, mat particles are preferably dispersed, and the refractive index of the material other than the mat particles in the light scattering layer is preferably in the range of 1.50 to 2.00, and the low refractive index The refractive index of the layer is preferably in the range of 1.20 to 1.49. In the present invention, the light scattering layer has both antiglare properties and hard coat properties, and may be a single layer or a plurality of layers, for example, two to four layers.

  The antireflection layer has an uneven surface shape, centerline average roughness Ra is 0.08 to 0.40 μm, 10-point average roughness Rz is 10 times or less Ra, average unevenness distance Sm is 1 to 100 μm, unevenness The standard deviation of the height of the convex part from the deepest part is 0.5 μm or less, the standard deviation of the average unevenness distance Sm with respect to the center line is 20 μm or less, and the surface with the inclination angle of 0 to 5 ° is 10% or more. It is preferable that it is designed so that sufficient anti-glare property and visual uniform matte feeling can be achieved.

The color of the reflected light under the C light source (CIE standard average daylight type C) is a ^* value of −2 to 2 and b ^* value of −3 to 3 in the L * a * b * chromaticity coordinate space. It is preferable that the ratio between the minimum value and the maximum value of the reflectance within the range of 380 nm to 780 nm is 0.5 to 0.99, since the color of the reflected light becomes neutral. Furthermore, it is preferable to set the b ^* value of transmitted light under a C light source to 0 to 3 because the yellow color of white display when applied to a display device is reduced. Furthermore, if a 120 μm × 40 μm grid is inserted between the surface light source and the antireflection layer and the luminance distribution is measured on the film, the standard deviation of the luminance distribution is 20 or less. Since glare when the polarizing plate of the invention is applied is reduced, it is preferable.

  The antireflection layer that can be used in the present invention suppresses reflection of external light by setting its optical properties to a specular reflectance of 2.5% or less, a transmittance of 90% or more, and a 60 ° glossiness of 70% or less. This is preferable because visibility is improved. In particular, the specular reflectance is more preferably 1% or less, and most preferably 0.5% or less. Haze 20% to 50%, ratio of internal haze / total haze value 0.3 to 1, haze value after formation of low refractive index layer from haze value up to light scattering layer within 15%, comb width 0 .Transparent image clarity at 5 mm, 20% to 50%, vertical transmission light / transmittance ratio in the direction inclined by 2 ° from vertical is 1.5 to 5.0, thereby preventing glare on a high-definition LCD panel. This is preferable because blurring of characters and the like is reduced.

(Low refractive index layer)
The refractive index of the low refractive index layer that can be used in the present invention is preferably 1.20 to 1.49, more preferably 1.30 to 1.44. Furthermore, the low refractive index layer preferably satisfies the following formula (19) from the viewpoint of reducing the reflectance.
Formula (19): (m / 4) λ × 0.7 <n _L d _L <(m / 4) λ × 1.3
In the formula, m is a positive odd number, n _L is the refractive index of the low refractive index layer, and d _L is the film thickness (nm) of the low refractive index layer. Further, λ is a wavelength, which is a value in the range of 500 to 550 nm.

The material for forming the low refractive index layer is described below.
The low refractive index layer preferably contains a fluorine-containing polymer as a low refractive index binder.
As the fluorine polymer, a fluorine-containing polymer which is crosslinked by heat or ionizing radiation and having a dynamic friction coefficient of 0.03 to 0.20, a contact angle with water of 90 to 120 °, and a sliding angle of pure water of 70 ° or less is preferable. When the polarizing plate according to the present invention is mounted on an image display device, the lower the peel strength from a commercially available adhesive tape, the easier it is to peel off after sticking a seal or memo. It is preferably 500 gf (4.9 N) or less, more preferably 300 gf (3.96 N) or less, and most preferably 100 gf (0.98 N) or less. Also, the higher the surface hardness measured with a microhardness meter, the harder it is to scratch. The surface hardness is preferably 0.3 GPa or more, more preferably 0.5 GPa or more.

  Examples of the fluorine-containing polymer used in the low refractive index layer include perfluoroalkyl group-containing silane compounds {for example, hydrolysates and dehydrated condensates of (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane}. In addition, a fluorine-containing copolymer having a fluorine-containing monomer unit and a structural unit for imparting crosslinking reactivity as constituent components can be mentioned.

  Specific examples of the fluorine-containing monomer include fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, perfluorooctylethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole, etc.), (Meth) acrylic acid partial or fully fluorinated alkyl ester derivatives [e.g. "Biscoat 6FM" {manufactured by Osaka Organic Chemical Industry Co., Ltd.} or "M-2020" {manufactured by Daikin Industries Ltd.}], complete or Partially fluorinated vinyl ethers and the like can be mentioned, and perfluoroolefins are preferable, and hexafluoropropylene is particularly preferable from the viewpoint of refractive index, solubility, transparency, availability, and the like.

  As a structural unit for imparting crosslinking reactivity, a structural unit obtained by polymerization of a monomer having a self-crosslinkable functional group in the molecule in advance, such as glycidyl (meth) acrylate or glycidyl vinyl ether, a carboxyl group or a hydroxy group, Polymerization of monomers having amino groups, sulfo groups, etc. {eg (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, maleic acid, crotonic acid, etc.} Or a structural unit obtained by introducing a crosslinking reactive group such as a (meth) acryloyl group into the structural unit by a polymer reaction (for example, a method in which acrylic acid chloride is allowed to act on a hydroxy group). ) It is.

  In addition to the fluorine-containing monomer unit and the structural unit for imparting crosslinking reactivity, a monomer that does not contain a fluorine atom can be copolymerized as appropriate from the viewpoint of solubility in a solvent, film transparency, and the like. There are no particular limitations on the monomer units that can be used in combination. For example, olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic esters (methyl acrylate, methyl acrylate, ethyl acrylate, acrylic acid 2) -Ethylhexyl), methacrylates (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, vinyl toluene, α-methylstyrene, etc.), vinyl ethers (methyl) Vinyl ether, ethyl vinyl ether, cyclohexyl vinyl ether, etc.), vinyl esters (vinyl acetate, vinyl propionate, vinyl cinnamate etc.), acrylamides (Nt-butylacrylamide, N-cyclo) Hexyl acrylamide), methacrylamides, and acrylonitrile derivatives.

  As described in JP-A-10-25388 and JP-A-10-147739, the above polymer may be used in combination with a curing agent as appropriate.

(Light scattering layer)
The light scattering layer is formed for the purpose of imparting to the film a light diffusibility due to at least one of surface scattering and internal scattering and a hard coat property for improving the scratch resistance of the film. Therefore, it is formed including a binder for imparting hard coat properties, matte particles for imparting light diffusibility, and inorganic fillers for increasing the refractive index, preventing cross-linking shrinkage, and increasing the strength as necessary. The In addition, by providing such a light scattering layer, the light scattering layer also functions as an antiglare layer, and the polarizing plate has an antiglare layer.

  The thickness of the light scattering layer is preferably 1 to 10 μm and more preferably 1.2 to 6 μm for the purpose of imparting hard coat properties. If the film thickness of the light scattering layer is not less than the lower limit, problems such as insufficient hardware properties are unlikely to occur, and if the thickness is not more than the upper limit, inconveniences such as curling and brittleness are deteriorated and workability is insufficient. Is preferable because it is difficult to cause.

  The binder of the light scattering layer is preferably a polymer having a saturated hydrocarbon chain or a polyether chain as the main chain, and more preferably a polymer having a saturated hydrocarbon chain as the main chain. The binder polymer preferably has a crosslinked structure. As the binder polymer having a saturated hydrocarbon chain as a main chain, a polymer of an ethylenically unsaturated monomer is preferable. As the binder polymer having a saturated hydrocarbon chain as the main chain and having a crosslinked structure, a (co) polymer of monomers having two or more ethylenically unsaturated groups is preferable. In order to make the binder polymer have a high refractive index, the monomer structure contains an aromatic ring, at least one atom selected from halogen atoms other than fluorine, sulfur atoms, phosphorus atoms, and nitrogen atoms. You can also choose.

  Examples of the monomer having two or more ethylenically unsaturated groups include esters of polyhydric alcohol and (meth) acrylic acid {for example, ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, hexanediol di ( (Meth) acrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (Meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3- Chlorohexane tetramethacrylate, polyurethane polyacrylate, polyester polyacrylate}, modified ethylene oxide, vinylbenzene and derivatives thereof (for example, 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1,4 -Divinylcyclohexanone), vinyl sulfone (e.g. divinyl sulfone), acrylamide (e.g. methylene bisacrylamide) and methacrylamide. Two or more of these monomers may be used in combination.

  Specific examples of the high refractive index monomer include bis (4-methacryloylthiophenyl) sulfide, vinyl naphthalene, vinyl phenyl sulfide, 4-methacryloxyphenyl-4′-methoxyphenyl thioether, and the like. Two or more of these monomers may be used in combination.

  Polymerization of these monomers having an ethylenically unsaturated group can be performed by irradiation with ionizing radiation or heating in the presence of a photo radical initiator or a thermal radical initiator. Accordingly, a coating liquid containing a monomer having an ethylenically unsaturated group, a photo radical initiator or a thermal radical initiator, mat particles and an inorganic filler is prepared, and the coating liquid is applied onto a protective film, and then ionizing radiation or heat is applied. It can harden | cure by the polymerization reaction by and can form an antireflection layer. As these photo radical initiators, known ones can be used.

  The polymer having a polyether as the main chain is preferably a ring-opening polymer of a polyfunctional epoxy compound. The ring-opening polymerization of the polyfunctional epoxy compound can be performed by irradiation with ionizing radiation or heating in the presence of a photoacid generator or a thermal acid generator. Therefore, a coating solution containing a polyfunctional epoxy compound, a photoacid generator or a thermal acid generator, matte particles and an inorganic filler is prepared, and the coating solution is applied on a protective film and then cured by ionizing radiation or heat polymerization reaction. Thus, an antireflection layer can be formed.

  Instead of or in addition to a monomer having two or more ethylenically unsaturated groups, a monomer having a crosslinkable functional group is used to introduce a crosslinkable functional group into the polymer, and this crosslinkable functional group reacts. A crosslinked structure may be introduced into the binder polymer.

Examples of the crosslinkable functional group include isocyanate group, epoxy group, aziridine group, oxazoline group, aldehyde group, carbonyl group, hydrazine group, carboxyl group, methylol group and active methylene group. Vinylsulfonic acid, acid anhydride, cyanoacrylate derivative, melamine, etherified methylol, ester and urethane, and metal alkoxide such as tetramethoxysilane can also be used as a monomer for introducing a crosslinked structure. A functional group that exhibits crosslinkability as a result of the decomposition reaction, such as a block isocyanate group, may be used. That is, in the present invention, the crosslinkable functional group may not react immediately but may exhibit reactivity as a result of decomposition.
These binder polymers having a crosslinkable functional group can form a crosslinked structure by heating after coating.

For the purpose of imparting antiglare properties, the light scattering layer contains matte particles having an average particle diameter of 1 to 10 μm, preferably 1.5 to 7.0 μm, such as inorganic compound particles or resin particles, for the purpose of imparting antiglare properties. Is done. Specific examples of the matte particles include preferably particles of inorganic compounds such as silica particles and TiO ₂ particles; resin particles such as acrylic particles, crosslinked acrylic particles, polystyrene particles, crosslinked styrene particles, melamine resin particles, and benzoguanamine resin particles. It is done. Of these, crosslinked styrene particles, crosslinked acrylic particles, crosslinked acrylic styrene particles, and silica particles are preferable. The shape of the mat particles can be either spherical or irregular.

  Two or more kinds of mat particles having different particle diameters may be used in combination. It is possible to impart anti-glare properties with mat particles having a larger particle size and to impart other optical characteristics with mat particles having a smaller particle size.

  Further, the particle size distribution of the mat particles is most preferably monodisperse, and the particle sizes of the particles are preferably closer to each other. For example, when particles having a particle size of 20% or more than the average particle size are defined as coarse particles, the proportion of coarse particles is preferably 1% or less, more preferably 0.1% of the total number of particles. % Or less, more preferably 0.01% or less. Matt particles having such a particle size distribution are obtained by classification after a normal synthesis reaction, and a matting agent having a more preferable distribution can be obtained by increasing the number of classifications or increasing the degree of classification.

The mat particles are contained in the light scattering layer so that the amount of mat particles in the formed light scattering layer is preferably 10 to 1000 mg / m ² , more preferably 100 to 700 mg / m ² .
The particle size distribution of the matte particles is measured by a Coulter counter method, and the measured distribution is converted into a particle number distribution.

The light scattering layer is made of an oxide of at least one metal selected from titanium, zirconium, aluminum, indium, zinc, tin, and antimony, in addition to the matte particles, in order to increase the refractive index of the layer. Thus, it is preferable that an inorganic filler having an average particle diameter of 0.2 μm or less, preferably 0.1 μm or less, more preferably 0.06 μm or less is contained.
Conversely, in order to increase the difference in refractive index from the mat particles, it is also preferable to use a silicon oxide in order to keep the refractive index of the light scattering layer using the high refractive index mat particles low. The preferred particle size is the same as that of the aforementioned inorganic filler.

Specific examples of the inorganic filler used in the light scattering layer include TiO ₂ , ZrO ₂ , Al ₂ O ₃ , In ₂ O ₃ , ZnO, SnO ₂ , Sb ₂ O ₃ , ITO and SiO ₂ . TiO ₂ and ZrO ₂ are particularly preferable in terms of increasing the refractive index. The surface of the inorganic filler is preferably subjected to a silane coupling treatment or a titanium coupling treatment, and a surface treatment agent having a functional group capable of reacting with a binder species on the filler surface is preferably used.

  The amount of these inorganic fillers added is preferably 10 to 90% of the total mass of the light scattering layer, more preferably 20 to 80%, and particularly preferably 30 to 75%.

  Such a filler does not scatter because the particle size is sufficiently smaller than the wavelength of light, and a dispersion in which the filler is dispersed in a binder polymer behaves as an optically uniform substance.

  The bulk refractive index of the mixture of binder and inorganic filler in the light scattering layer is preferably 1.50 to 2.00, more preferably 1.51 to 1.80. In order to make the refractive index within the above range, the kind and amount ratio of the binder and the inorganic filler may be appropriately selected. How to select can be easily known experimentally in advance.

  In order to ensure surface uniformity such as uneven coating, uneven drying, point defects, etc., the light scattering layer should be coated with either a fluorine-based or silicone-based surfactant, or both for forming the light scattering layer. Contained in the composition. In particular, a fluorine-based surfactant is preferably used because an effect of improving surface defects such as coating unevenness, drying unevenness, and point defects of the antireflection layer preferably used in the present invention appears in a smaller addition amount. The purpose is to increase productivity by giving high-speed coating suitability while improving surface uniformity.

[AR film]
Next, an antireflection layer (AR film) in which a middle refractive index layer, a high refractive index layer, and a low refractive index layer are laminated in this order on the protective film will be described.

An antireflection layer comprising at least a middle refractive index layer, a high refractive index layer, and a low refractive index layer (outermost layer) in order on the protective film is designed to have a refractive index satisfying the following relationship. .
Refractive index of high refractive index layer> refractive index of medium refractive index layer> refractive index of protective film> refractive index of low refractive index layer

Further, a hard coat layer may be provided between the protective film and the medium refractive index layer. Further, it may be composed of a medium refractive index hard coat layer, a high refractive index layer and a low refractive index layer. For example, JP-A-8-122504, 8-110401, 10-300902, Examples thereof include antireflection layers described in JP-A-2002-243906, JP-A No. 2000-11706, and the like.
Further, other functions may be imparted to each layer. For example, an antifouling low refractive index layer and an antistatic high refractive index layer (for example, JP-A-10-206603, JP-A-2002-2002). No. 243906 gazette) and the like.

  The haze of the antireflection layer is preferably 5% or less, more preferably 3% or less. Further, the surface strength of the film is preferably H or more, more preferably 2H or more, and most preferably 3H or more in a pencil hardness test according to JIS K-5400.

(High refractive index layer and medium refractive index layer)
The layer having a high refractive index of the antireflection layer is composed of a cured film containing at least an inorganic compound fine particle having a high refractive index having an average particle diameter of 100 nm or less and a matrix binder.

  Examples of the high refractive index inorganic compound fine particles include inorganic compounds having a refractive index of 1.65 or more, preferably those having a refractive index of 1.9 or more. Examples thereof include oxides such as Ti, Zn, Sb, Sn, Zr, Ce, Ta, La, and In, and composite oxides containing these metal atoms.

  In order to obtain such fine particles, the surface of the particles is treated with a surface treatment agent (for example, silane coupling agents, etc .: JP-A Nos. 1-295503, 11-153703, 2000-9908). Gazette, anionic compound or organometallic coupling agent: described in JP-A No. 2001-310432, etc.), core-shell structure with high refractive index particles as a core (described in JP-A No. 2001-166104, etc.) And a specific dispersant (see, for example, JP-A No. 11-153703, US Pat. No. 6,210,858 and JP-A No. 2002-277609).

Examples of the material forming the matrix include conventionally known thermoplastic resins and curable resin films.
More preferable materials include a polyfunctional compound-containing composition having at least two polymerizable groups of at least one of radically polymerizable and cationically polymerizable, a composition containing an organometallic compound containing a hydrolyzable group, And at least one composition selected from compositions containing the partial condensates thereof, for example, JP-A 2000-47004, 2001-315242, 2001-31871, 2001- And compounds described in Japanese Patent No. 296401.

  A curable film obtained from a colloidal metal oxide obtained from a hydrolyzed condensate of metal alkoxide and a metal alkoxide composition is also preferred. For example, it describes in Unexamined-Japanese-Patent No. 2001-293818.

  The refractive index of the high refractive index layer is preferably 1.70 to 2.20. The thickness of the high refractive index layer is preferably 5 nm to 10 μm, and more preferably 10 nm to 1 μm.

  The refractive index of the middle refractive index layer is adjusted to be a value between the refractive index of the low refractive index layer and the refractive index of the high refractive index layer. The refractive index of the middle refractive index layer is preferably 1.50 to 1.70. The thickness is preferably 5 nm to 10 μm, and more preferably 10 nm to 1 μm.

(Low refractive index layer)
The low refractive index layer is sequentially laminated on the high refractive index layer. The refractive index of the low refractive index layer is preferably 1.20 to 1.55. More preferably, it is 1.30-1.50.

  The low refractive index layer is preferably constructed as an outermost layer having scratch resistance and antifouling properties. As means for greatly improving the scratch resistance, imparting slipperiness to the surface is effective, and conventionally known means for thin film layers including introduction of silicone, introduction of fluorine, and the like can be applied.

The fluorine-containing compound is preferably a compound containing a crosslinkable or polymerizable functional group containing a fluorine atom in a range of 35 to 80% by mass, for example, paragraph numbers [0018] to [0026] of JP-A-9-222503. Examples thereof include the compounds described in paragraph Nos. [0019] to [0030] of JP-A-11-38202, paragraph numbers [0027] to [0028] of JP-A-2001-40284, JP-A 2000-284102, and the like.
The refractive index of the fluorine-containing compound is preferably 1.35 to 1.50. More preferably, it is 1.36-1.47.

  The silicone compound is preferably a compound having a polysiloxane structure, containing a curable functional group or a polymerizable functional group in the polymer chain and having a crosslinked structure in the film. For example, reactive silicone [for example, “Silaplane” {manufactured by Chisso Corporation etc.]], polysiloxane containing silanol groups at both ends (Japanese Patent Laid-Open No. 11-258403, etc.) and the like can be mentioned.

  The crosslinking or polymerization reaction of at least one of the fluorine-containing polymer and the siloxane polymer having a crosslinking or polymerizable group is performed simultaneously with the application of the coating composition for forming the outermost layer containing a polymerization initiator, a sensitizer and the like. Alternatively, it is preferable to form the low refractive index layer by light irradiation or heating after coating.

A sol / gel cured film in which an organometallic compound such as a silane coupling agent and a specific fluorine-containing hydrocarbon group-containing silane coupling agent are cured by a condensation reaction in the presence of a catalyst is also preferable.
For example, a polyfluoroalkyl group-containing silane compound or a partially hydrolyzed condensate thereof (Japanese Patent Laid-Open Nos. 58-142958, 58-147483, 58-147484, Japanese Patent Laid-Open Nos. 9-157582, 11) -106704), silyl compounds containing a poly (perfluoroalkyl ether) group which is a fluorine-containing long chain group (Japanese Patent Application Laid-Open Nos. 2000-117902, 2001-48590, 2002-53804). Etc.) and the like.

  The low refractive index layer has an average primary particle diameter of 1 to 150 nm such as a filler {eg, silicon dioxide (silica), fluorine-containing particles (magnesium fluoride, calcium fluoride, barium fluoride) as additives other than the above. Low refractive index inorganic compounds, organic fine particles described in paragraphs [0020] to [0038] of JP-A-11-3820}, silane coupling agents, slip agents, surfactants, and the like. .

  When the low refractive index layer is located below the outermost layer, the low refractive index layer may be formed by a vapor phase method (vacuum deposition method, sputtering method, ion plating method, plasma CVD method, etc.). The coating method is preferable because it can be manufactured at a low cost.

  The film thickness of the low refractive index layer is preferably 30 to 200 nm, more preferably 50 to 150 nm, and most preferably 60 to 120 nm.

(Hard coat layer)
The hard coat layer is provided on the surface of the protective film in order to impart physical strength to the protective film provided with the antireflection layer. In particular, it is preferably provided between the protective film and the high refractive index layer. The hard coat layer is preferably formed by a crosslinking reaction or a polymerization reaction of a light and / or heat curable compound. The curable functional group in the curable compound is preferably a photopolymerizable functional group. Also preferred are hydrolyzable functional group-containing organometallic compounds and organoalkoxysilyl compounds.

Specific examples of these compounds are the same as those exemplified for the high refractive index layer.
Specific examples of the constituent composition of the hard coat layer include those described in JP-A Nos. 2002-144913, 2000-9908, and WO 00/46617.

  The high refractive index layer can also serve as a hard coat layer. In such a case, it is preferable to form fine particles dispersed in the hard coat layer using the method described for the high refractive index layer.

  The hard coat layer can also serve as an antiglare layer containing particles having an average particle size of 0.2 to 10 μm and imparted with an antiglare function (antiglare function).

  The film thickness of the hard coat layer can be appropriately designed depending on the application. The film thickness of the hard coat layer is preferably 0.2 to 10 μm, more preferably 0.5 to 7 μm.

  The surface strength of the hard coat layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher in a pencil hardness test according to JIS K5400. Further, in the Taber test according to JIS K5400, the smaller the wear amount of the test piece before and after the test, the better.

(Other layers of antireflection layer)
Further, a forward scattering layer, a primer layer, an antistatic layer, an undercoat layer, a protective layer, and the like may be provided.

(Antistatic layer)
When an antistatic layer is provided, it is preferable to impart conductivity with a volume resistivity of 10 ⁻⁸ (Ωcm ⁻³ ) or less. The use of hygroscopic substances, water-soluble inorganic salts, certain surfactants, cationic polymers, anionic polymers, colloidal silica, etc. can give a volume resistivity of 10 ⁻⁸ (Ωcm ⁻³ ). There is a problem that dependency is large, and sufficient conductivity cannot be secured at low humidity. Therefore, a metal oxide is preferable as the conductive layer material. Some metal oxides are colored, but using these metal oxides as the conductive layer material is not preferable because the entire film is colored. Zn, Ti, Sn, Al, In, Si, Mg, Ba, Mo, W, or V can be used as the metal that forms the metal oxide without coloring, and a metal oxide containing these as main components is used. It is preferable.

Specific examples of the metal oxide include ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , In _2.
O ₃ , SiO ₂ , MgO, BaO, MoO ₃ , WO ₃ , V ₂ O ₅ or the like or a composite oxide thereof is preferable, and ZnO, TiO ₂ and SnO ₂ are particularly preferable. Examples of containing different atoms include, for example, additives such as Al and In for ZnO, addition of Sb, Nb and halogen elements for SnO ₂ , and Nb and Ta for TiO ₂ . Addition is effective.

Furthermore, as described in Japanese Patent Publication No. 59-6235, a material obtained by adhering the above metal oxide to other crystalline metal particles or fibrous materials (for example, titanium oxide) may be used. Note the volume resistivity and surface resistivity are different physical values, can not be simply compared, in order to ensure 10 ^-8 (Ωcm ^-3) or less of the conductive volume resistivity value, the charging The prevention layer should just have the surface resistance value of ¹⁰ < ^-10 > (ohm / square) or less, More preferably, it is 10 < ^-8 > (ohm / square). The surface resistance value of the antistatic layer needs to be measured as a value when the antistatic layer is the outermost layer, and can be measured in the middle of forming the laminated film.

[Liquid Crystal Display]
The cellulose acylate film or the polarizing plate obtained by laminating the cellulose acylate film and the polarizing film is advantageously used for a liquid crystal display device, particularly a transmissive liquid crystal display device.
The transmissive liquid crystal display device includes a liquid crystal cell and two polarizing plates disposed on both sides thereof. A polarizing plate consists of a polarizing film and two transparent protective films arrange | positioned at the both sides. The liquid crystal cell carries a liquid crystal between two electrode substrates.
One polarizing plate of the present invention is disposed on one side of the liquid crystal cell, or two are disposed on both sides of the liquid crystal cell.
The liquid crystal cell is preferably in VA mode, OCB mode, IPS mode, or TN mode.
In a VA mode liquid crystal cell, rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied.
The VA mode liquid crystal cell includes (1) a narrowly defined VA mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied, and substantially horizontally when a voltage is applied (Japanese Patent Laid-Open No. Hei 2-). (2) Liquid crystal cell (SID97, Digest of tech.Papers 28 (1997) 845, VA mode multi-domain (MVA mode) for viewing angle expansion. (3) A liquid crystal cell in a mode (n-ASM mode) in which rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied and twisted multi-domain alignment is applied when a voltage is applied (Preliminary Collection 58- 59 (described in 1998)) and (4) SURVAVAL mode liquid crystal cells (announced at LCD International 98).
In the case of a VA mode liquid crystal display device, when only one polarizing plate of the present invention is used, it is preferably used on the backlight side.

The OCB mode liquid crystal cell is a bend alignment mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned in a substantially opposite direction (symmetrically) between an upper portion and a lower portion of the liquid crystal cell. Liquid crystal display devices using a bend alignment mode liquid crystal cell are disclosed in US Pat. Nos. 4,583,825 and 5,410,422. Since the rod-like liquid crystal molecules are symmetrically aligned at the upper and lower portions of the liquid crystal cell, the bend alignment mode liquid crystal cell has a self-optical compensation function.
For this reason, this liquid crystal mode is also called an OCB (Optically Compensatory Bend) liquid crystal mode. The bend alignment mode liquid crystal display device has an advantage of high response speed.

The optical film of the present invention may be used as a support for an optical compensation sheet of an IPS liquid crystal display device and an ECB liquid crystal display device having IPS mode and ECB mode liquid crystal cells, or as a protective film for a polarizing plate. In these modes, the liquid crystal material is aligned substantially in parallel during black display, and black is displayed by aligning liquid crystal molecules in parallel with the substrate surface in the absence of applied voltage.
In a TN mode liquid crystal cell, rod-like liquid crystalline molecules are substantially horizontally aligned when no voltage is applied, and are twisted and aligned at 60 to 120 °.
The TN mode liquid crystal cell is most frequently used as a color TFT liquid crystal display device, and is described in many documents.

When the optical film or polarizing plate of the present invention is used in a liquid crystal display device, it is preferable that the liquid crystal display device further has an optically anisotropic layer satisfying the following formulas (10) and (11). In such a liquid crystal display device, the above-described color shift problem is further improved.
This embodiment is particularly preferable when the liquid crystal cell is in the VA mode.
Formula (10) Rt (550) / Re (550)> 10
Formula (11) Rth (650) -Rth (450) <0

  The material constituting the optically anisotropic layer satisfying the formulas (10) and (11) is not particularly limited, but a cellulose ester film or a cyclic cycloolefin film containing an ultraviolet absorber is preferably used. I can do it.

As described above, when the optical film or polarizing plate of the present invention is used in combination with an optically anisotropic layer satisfying the above formulas (10) and (11), the optical film of the present invention can improve the problem of color shift. It is preferable that the following formulas (1) to (3) are further satisfied.
Formula (1) Re (550)> 20 nm
Formula (2) 0.5 <Nz <10
Formula (3) −2.5 × Re (550) +300 <Rth (550) <− 2.5 × Re (550) +500
(In the formula, Re (λ) and Rth (λ) are in-plane and out-of-plane retardation (unit: n) measured by incidence of light having a wavelength of λ nm, respectively, and Nz = Rth (550) / Re ( 550) +0.5)

The optical film of the present invention more preferably satisfies the following formulas (1) ′ to (3) ′, more preferably formulas (4) to (7), and particularly preferably formulas (4a) to (7a). Further preferred.
Formula (1) ′ Re (550)> 30 nm
Formula (2) ′ 1.5 ≦ Nz <10
Formula (3) ′ −2.5 × Re (550) +320 <Rth (550) <− 2.5 × Re (550) +480

Formula (4) 0.60 <Re (450) / Re (550) <1.0
Formula (5) 1.0 <Re (650) / Re (550) <1.25
Formula (6) 0.60 <Rth (450) / Rth (550) <1.0
Formula (7) 1.0 <Rth (650) / Rth (550) <1.25

Formula (4a) 0.70 <Re (450) / Re (550) <1.0
Formula (5a) 1.0 <Re (650) / Re (550) <1.15
Formula (6a) 0.70 <Rth (450) / Rth (550) <1.0
Formula (7a) 1.0 <Rth (650) / Rth (550) <1.15

  EXAMPLES Hereinafter, although an Example and a comparative example further demonstrate this invention, this invention is not restrict | limited to the following example.

[Example 1]

<Synthesis of Exemplary Compound (16) of General Formula (I)>
30 ml (0.24 mol) of cyanoacetic acid isopropyl ester was added to a 500 ml N-methylpyrrolidone solution of 62.7 g (0.2 mol) of compound (1-C), and the mixture was stirred at an internal temperature of 120 ° C. for 5 hours. After cooling, ethyl acetate and water were added for liquid separation, and the organic layer was washed with water. The organic layer was dried over magnesium sulfate, and the solvent was distilled off under reduced pressure to solidify. The solid was dispersed in an acetone / hexane mixed solvent, and filtration was repeated twice to obtain 58.0 g of compound (16-D) (yield 93 mol%).

  To a solution of 10.49 g (44 mmol) of compound (16-E) (manufactured by Yantai valiant Fine Chem.) In 100 ml of tetrahydrofuran (THF) was added 3.4 ml (44 mmol) of methanesulfonic acid chloride under ice cooling, and N, N -8.05 ml (46.2 mmol) of diisopropylethylamine was slowly added dropwise. After stirring for 1 hour, 8.05 ml (46.2 mmol) of N, N-diisopropylethylamine was added, and a solution of compound (16-D) 6.19 g (20 mmol) in 50 ml of tetrahydrofuran was added dropwise. Thereafter, a 20 ml tetrahydrofuran solution containing 0.05 g of N, N-dimethylaminopyridine (DMAP) was added dropwise. After stirring for 1 hour under ice cooling, the mixture was warmed to room temperature and stirred for 6 hours. Ethyl acetate and water were added for liquid separation, and the organic layer was washed with water, 1N aqueous hydrochloric acid and water in this order. The organic layer was dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. 5.4 g of Exemplified Compound (16) was obtained by purification with silica gel column chromatography using a mixed solvent of methylene chloride / methanol as an eluent (yield 36 mol%).

<Film formation of cellulose acylate film>
(1) Cellulose acylate By adding sulfuric acid as a catalyst to cellulose as a raw material, and further adding carboxylic anhydride as a raw material for acyl substituents to carry out an acylation reaction, and then neutralizing and saponifying and aging Prepared. At this time, by adjusting the amount of catalyst, the type and amount of carboxylic anhydride, the amount of neutralizing agent added, the amount of water added, the reaction temperature, and the aging temperature, the type of acyl group, the degree of substitution, the bulk density, and the degree of polymerization Different cellulose acylates were prepared. Further, the low molecular weight component of the cellulose acylate was removed by washing with acetone.
Among the cellulose acylates prepared as described above, the following dope preparation was performed using cellulose acylate having an acetyl group substitution degree of 2.87 and DS6 / (DS2 + DS3 + DS6) = 0.310.

(2) Dope Preparation <1-1> Cellulose Acylate Solution The following composition is put into a mixing tank, stirred to dissolve each component, and further heated at 90 ° C. for about 10 minutes. It filtered with the sintered metal filter with an average hole diameter of 10 micrometers.

―――――――――――――――――――――――――――――――――
Cellulose acylate solution ――――――――――――――――――――――――――――――――――
Cellulose acylate 100.0 parts by mass Triphenyl phosphate 4.0 parts by mass Biphenyl diphenyl phosphate 4.0 parts by mass Ethyl phthalyl ethyl glycolate 4.0 parts by mass Methylene chloride 403.0 parts by mass Methanol 60.2 parts by mass ―――――――――――――――――――――――――――――――――

<1-2> Matting Agent Dispersion Solution Next, the following composition containing the cellulose acylate solution prepared by the above method was charged into a dispersing machine to prepare a matting agent dispersion.

――――――――――――――――――――――――――――――――――
Matting agent dispersion ――――――――――――――――――――――――――――――――――
Silica particles having an average particle size of 16 nm (Aerosil R972, manufactured by Nippon Aerosil Co., Ltd. 2.0 parts by mass methylene chloride 72.4 parts by mass methanol 10.8 parts by mass cellulose acylate solution 10.3 parts by mass ―――――――――――――――――――――――――――

<1-3> Retardation developer solution Next, the following composition containing the cellulose acylate solution prepared by the above method is put into a mixing tank and dissolved by stirring while heating to prepare a retardation developer solution A. did.

―――――――――――――――――――――――――――――――――
Retardation developer solution A
―――――――――――――――――――――――――――――――――
Illustrative compound (16) of general formula (I) 14.0 parts by weight Illustrative compound (III-1) 7.8 parts by weight Methylene chloride 63.5 parts by weight Methanol 9.5 parts by weight Cellulose acylate solution 14.0 parts by weight ―――――――――――――――――――――――――――――――――

100 parts by mass of the cellulose acylate solution, 1.35 parts by mass of the matting agent dispersion, and the retardation developing agent in the cellulose acylate film per 100 parts by mass of cellulose acylate are exemplified compounds of the general formula (I) ( A dope for film formation was prepared by mixing the retardation developer solution in such an amount that 16) was 3.5 parts by mass and the exemplary compound (III-1) was 2.0 parts by mass.
The exemplified compound (16) of the general formula (I) exhibited a nematic liquid crystal phase in a temperature range of 120 ° C to 170 ° C.

(Casting)
The above dope was cast using a glass plate casting apparatus. The film was dried for 6 minutes with warm air at a supply air temperature of 70 ° C., and the film peeled off from the glass plate was fixed to the frame. It dried and manufactured the cellulose acylate film with a film thickness of 108 micrometers.
Next, the obtained film was transversely stretched at a stretching rate of 30% / min up to a stretching ratio of 20% using a tenter under the condition of 160 ° C., and then the film was wound up. The finished cellulose acylate film had a thickness of 92 μm. This film was designated as film 101.

(Production of films 102 to 109)
The types and addition amounts of the compounds were adjusted so that the retardation developer solution of film 101 had the composition shown in Table 2, and film formation and stretching were performed in the same manner as film 101 to produce films 102 to 109.
Further, the values of the formula (1) of the Rth raising agent used in these films were all good values of 5.0 or more as shown below.
III-1 13
II-334 28
IV-16 18
IV-18 24
IV-43 22
V-23 17

<Re, Rth at film wavelengths of 450, 550 and 650 nm>
Re and Rth at wavelengths of 450, 550 and 650 nm of this film were measured with a KOBRA 21ADH (manufactured by Oji Scientific Instruments) birefringence meter according to the method described above.
The results are shown in Table 2. From Table 2, it can be seen that the values of Re and Rth at wavelengths of 450, 550 and 650 nm of the cellulose acylate film produced by the production method of the present invention satisfy all the relationships of the above formulas (A) to (D).

<Preparation of polarizing plate>
A polarizing film was prepared by adsorbing iodine to a stretched polyvinyl alcohol film.
The produced cellulose acylate films 101 to 109 were attached to one side of the polarizing film using a polyvinyl alcohol-based adhesive. The saponification treatment was performed under the following conditions.
A 1.5 mol / liter aqueous sodium hydroxide solution was prepared and kept at 55 ° C. A 0.01 mol / liter dilute sulfuric acid aqueous solution was prepared and kept at 35 ° C. The produced cellulose acylate film was immersed in the aqueous sodium hydroxide solution for 2 minutes, and then immersed in water to thoroughly wash away the aqueous sodium hydroxide solution. Subsequently, after being immersed in the above-mentioned dilute sulfuric acid aqueous solution for 1 minute, it was immersed in water to sufficiently wash away the dilute sulfuric acid aqueous solution. Finally, the sample was thoroughly dried at 120 ° C.
A commercially available cellulose triacylate film (Fujitac TD80UF, manufactured by Fuji Photo Film Co., Ltd.) is saponified, and is attached to the opposite side of the polarizer using a polyvinyl alcohol adhesive, and at 70 ° C. for 10 minutes or more. Dried.
The transmission axis of the polarizing film and the slow axis of the cellulose acylate film produced as described above were arranged in parallel. The transmission axis of the polarizing film and the slow axis of a commercially available cellulose triacylate film were arranged so as to be orthogonal.

<Production of liquid crystal cell>
The liquid crystal cell has a cell gap between substrates of 3.6 μm, and a liquid crystal material having negative dielectric anisotropy (“MLC6608”, manufactured by Merck & Co., Inc.) is dropped and sealed between the substrates. Prepared by forming a layer. The retardation of the liquid crystal layer (that is, the product Δn · d of the thickness d (μm) of the liquid crystal layer and the refractive index anisotropy Δn) was set to 300 nm. The liquid crystal material was aligned so as to be vertically aligned.

<Mounting on VA panel>
A commercially available super high contrast product (HLC2-5618 manufactured by Sanlitz Co., Ltd.) was used for the upper polarizing plate (observer side) of the liquid crystal display device using the vertical alignment type liquid crystal cell. A polarizing plate provided with the cellulose acylate films 101 to 109 was placed on the lower polarizing plate (backlight side) so that the cellulose acylate film was on the liquid crystal cell side. The upper polarizing plate and the lower polarizing plate were attached to the liquid crystal cell via an adhesive. The crossed nicols were arranged so that the transmission axis of the upper polarizing plate was in the vertical direction and the transmission axis of the lower polarizing plate was in the horizontal direction.
A rectangular wave voltage of 55 Hz was applied to the liquid crystal cell. A normally black mode with 5 V white display and 0 V black display was set. The black display transmittance (%) at the azimuth angle of 45 degrees and the polar angle of 60 degrees and the color shift Δx between the azimuth angle of 45 degrees polar angle of 60 degrees and the azimuth angle of 180 degrees and polar angle of 60 degrees were obtained. .
Further, using the measuring device (EZ-Contrast 160D, manufactured by ELDIM) as the contrast ratio, the transmittance ratio (white display / black display), the visual field is displayed in eight stages from black display (L1) to white display (L8). The angle (a polar angle range with a contrast ratio of 10 or more and no black-side gradation inversion) was measured.
As a result of observing the produced liquid crystal display device, the liquid crystal panel using the film of the present invention was able to realize a neutral black display in both the front direction and the viewing angle direction.

Viewing angle (polar angle range with contrast ratio of 10 or more and no black-side gradation inversion)
○ Polar angle 80 ° or more in top / bottom / left / right ○ △ Polar angle 80 ° or more in three directions, top / bottom / left / right △ Polar angle 80 ° or more in two directions, top / bottom / right / left Color misregistration (Δx) when black is displayed at an angle of 80 ° or more
○ Less than 0.02 ○ △ 0.02-0.04
△ 0.04-0.06
× 0.06 or more

  Although it is possible to increase Re and Rth at 550 nm using only the Rth raising agent, it is difficult to satisfy all the conditions of the mathematical expressions (A) to (D) with respect to the wavelength dispersion characteristics. In the general formula (I) of the present invention, the wavelength dispersion characteristics of Re can be controlled to reverse dispersion with a short short wavelength, and the influence on Rth is extremely small. Therefore, when used together with an Rth increasing agent, both Re and Rth are large. In addition, appropriate chromatic dispersion control is possible.

[Example 2]
A film 201 was produced in the same manner except that the stretching process was changed as follows under the production conditions of the film 101 in Example 1.
Four sides were gripped with a biaxial stretching test apparatus (manufactured by Toyo Seiki Seisakusho Co., Ltd.), and stretching and shrinking processes were performed under the conditions shown in Table 3. As common conditions for the stretching and shrinking processes, after preheating for 2 minutes at a supply air temperature of 180 ° C. in each example before these processes, stretching in the TD direction and relaxation in the MD direction at this supply air temperature. went. It was separately confirmed that the supply air temperature and the film temperature were the same. After completion of these steps, air cooling was performed for 5 minutes while holding the clip. MD in the table indicates the casting direction at the time of casting the glass plate, and TD indicates the width direction perpendicular to the casting direction.
A liquid crystal panel was prepared in the same manner as in Example 1, and the viewing angle and color misregistration during black display were evaluated. Good results were obtained.

  It can be seen that by including both the stretching step and the relaxation step according to the present invention, a liquid crystal display device having a wide viewing angle and a small color shift during black display can be obtained.

[Example 3]
A 1.0 N potassium hydroxide solution (solvent: water / isopropyl alcohol / propylene glycol = 69.2 parts by mass / 15 parts by mass / 15.8 parts by mass) was added to the cellulose acylate films 101 and 108 produced in Example 1. the 10 ml / m ² was applied, after holding for 30 seconds in a state of about 40 ° C., scraped alkali solution, then washed with pure water, and remove the water droplets in the air knife. Then, it dried at 100 degreeC for 15 second.
The contact angle of the alkali-treated surface with pure water was measured and found to be 41 °.

(Formation of alignment film)
An alignment film coating solution having the following composition was applied to the alkali-treated surface with a # 16 wire bar coater at 28 ml / m ² . The alignment film was formed by drying with warm air of 60 ° C. for 60 seconds and further with warm air of 90 ° C. for 150 seconds.

───────────────────────────────────
Alignment film coating solution composition ───────────────────────────────────
Denatured polyvinyl alcohol 10 parts by weight Water 371 parts by weight Methanol 119 parts by weight Glutaraldehyde (crosslinking agent) 0.5 parts by weight Citrate ester (AS3, Sankyo Chemical Co., Ltd.) 0.35 parts by weight ────────────────────────────────

(Rubbing process)
The transparent support on which the alignment film is formed is transported at a speed of 20 m / min, a rubbing roll (300 mm diameter) is set so as to be rubbed at 45 ° with respect to the longitudinal direction, and rotated at 650 rpm. A rubbing treatment was performed on the alignment film installation surface. The contact length between the rubbing roll and the transparent support was set to 18 mm.

(Formation of optically anisotropic layer)
102 kg of methyl ethyl ketone, 40.01 kg of discotic liquid crystalline compound (following paragraph 40), 4.06 kg of ethylene oxide modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.), cellulose acetate butyrate (CAB531) −1, Eastman Chemical Co., Ltd.) 0.35 Kg, Photopolymerization initiator (Irgacure 907, Ciba Geigy Co., Ltd.) 1.31 Kg, Sensitizer (Kayacure DETX, Nippon Kayaku Co., Ltd.) 0.47 Kg is dissolved. did. To the solution, 0.1 kg of a fluoroaliphatic group-containing copolymer (Megafac F780 manufactured by Dainippon Ink, Inc.) was added to prepare a coating solution. The coating solution was continuously applied to the alignment film surface of the transparent support being conveyed at 20 m / min by rotating a # 3.2 wire bar at 391 rotations in the same direction as the film conveyance direction.

  The film is continuously heated from room temperature to 100 ° C. to dry the solvent, and then the film surface wind speed of the optically anisotropic layer containing the discotic liquid crystalline compound is 2.5 m / sec in the drying zone at 130 ° C. As described above, the discotic liquid crystalline compound was aligned by heating for about 90 seconds. Next, it is transported to a drying zone at 80 ° C., and an ultraviolet ray with an energy intensity of 600 mW is applied by an ultraviolet irradiation device (ultraviolet lamp: output 160 W / cm, emission length 1.6 m) with the surface temperature of the film being about 100 ° C. Was irradiated for 4 seconds to advance the crosslinking reaction, and the discotic liquid crystalline compound was fixed to the orientation. Then, it was allowed to cool to room temperature and wound into a cylindrical shape to form a roll. In this way, a roll-shaped optical compensation film was produced.

When the viscosity of the optically anisotropic layer was measured at a film surface temperature of 127 ° C., it was 695 cp (695 mPa · s). The viscosity is a result of measuring a liquid crystal layer (excluding the solvent) having the same composition as the optically anisotropic layer with a heating E-type viscosity system.
A part of the produced roll-shaped optical compensation film was cut out and used as a sample to measure optical characteristics. The Re retardation value of the optically anisotropic layer measured at a wavelength of 546 nm was 36 nm. Further, the angle (tilt angle) between the disc surface of the discotic liquid crystalline compound in the optically anisotropic layer and the support surface varied continuously in the depth direction of the layer, and averaged 28 °. Furthermore, when only the optically anisotropic layer was peeled from the sample and the average direction of the molecular symmetry axis of the optically anisotropic layer was measured, it was 45 ° with respect to the longitudinal direction of the optical compensation film.
<Evaluation of mounting on OCB panel>
These cellulose acylate film samples were processed into polarizing plates in the same manner as in Example 1.

<Mounting evaluation with liquid crystal display devices>
(Preparation of bend alignment liquid crystal cell)
A polyimide film was provided as an alignment film on a glass substrate with an ITO electrode, and the alignment film was rubbed. The obtained two glass substrates were faced to each other so that the rubbing directions were parallel to each other, and the cell gap was set to 4.7 μm. A bend-aligned liquid crystal cell was prepared by injecting a liquid crystal compound (ZLI1132, manufactured by Merck & Co., Inc.) having a Δn of 0.1396 into the cell gap.
Two polarizing plates prepared so as to sandwich the prepared bend alignment cell were attached. The rubbing direction of the liquid crystal cell and the rubbing direction of the optically anisotropic layer facing the liquid crystal cell were arranged to be antiparallel.
A rectangular wave voltage of 55 Hz was applied to the liquid crystal cell. A normally white mode of 2V white display and 5V black display was set. A voltage at which the transmittance at the front is minimized, that is, a black voltage is applied, and the black display transmittance (%) at an azimuth angle of 0 ° and a polar angle of 60 ° direction viewing angle and an azimuth angle of 0 ° and a polar angle of 60 ° A color shift Δx with an azimuth angle of 180 degrees and a polar angle of 60 degrees was determined. The results are shown in Table 4. Further, using the measuring device (EZ-Contrast 160D, manufactured by ELDIM) as the contrast ratio, the transmittance ratio (white display / black display), the visual field is displayed in eight stages from black display (L1) to white display (L8). The corner was measured. The results were organized as in Example 1. Both viewing angle and color shift during black display showed good performance.

[Example 4]
(Preparation of sample 401)
A cellulose acylate film sample was prepared in the same manner as in the dope (sample 101) used in the production of the film 101 of Example 1, except that the compound of general formula (I) and the Rth increasing agent were changed as shown in Table 4 below. A sample 401 was prepared.
As shown in Table 4, the optical performance of the manufactured sample 401 satisfies the above formulas (1) to (3).

(Preparation of retardation film C-1)
A stretched ARTON film having the retardation characteristics shown in Table 4 was prepared by the method described in International Publication No. 2003/032060 pamphlet, and designated as retardation film C-1.

(Preparation of protective film for polarizing plate with low moisture permeability barrier layer)
1) Coating of low moisture-permeable coating layer A triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 μm is unwound in a roll form, and using a coater having a throttle die, the following The coating solution for the low moisture permeability coating layer having the composition: It apply | coated on conditions with a conveyance speed of 30 m / min, and it dried at 60 degreeC for 5 minutes, and wound up.

───────────────────────────────────
Coating solution for low moisture-permeable coating layer ────────────────────────────────────
Chlorine-containing polymer: R204 12g
{"Saran Resin R204" manufactured by Asahi Kasei Life & Living Co., Ltd.}
Tetrahydrofuran 63g
───────────────────────────────────

2) Coating of hard coat layer An 80 μm-thick triacetyl cellulose film (Tac-TD80U, manufactured by Fuji Photo Film Co., Ltd.) coated with the low moisture-permeable coating layer is unwound in a roll form and throttled Using a coater having a die, a hard coat layer coating solution having the following composition was directly extruded and applied. After coating at a transfer speed of 30 m / min, drying at 30 ° C. for 15 seconds and 90 ° C. for 20 seconds, and further using a 160 W / cm air-cooled metal halide lamp (made by Eye Graphics Co., Ltd.) under a nitrogen purge. The coating layer was cured by irradiating with an ultraviolet ray with an irradiation amount of 90 mJ / cm ² to form an antiglare hard coat layer having a thickness of 6.0 μm and wound up.

───────────────────────────────────
Hard coat layer coating solution ───────────────────────────────────
PET-30 40.0g
DPHA 10.0g
Irgacure 184 2.0g
SX-350 (30%) 2.0g
Cross-linked acrylic-styrene particles (30%) 13.0 g
FP-13 0.06g
Sol liquid a 11.0g
Toluene 38.5g
───────────────────────────────────

The above-mentioned compounds used when preparing the coating solution for the hard coat layer are shown below.
DPHA: Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate [manufactured by Nippon Kayaku Co., Ltd.]
PET-30: A mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate [manufactured by Nippon Kayaku Co., Ltd.]
・ Irgacure 184: Polymerization initiator [Ciba Specialty Chemicals Co., Ltd.]
SX-350: average particle size 3.5 μm crosslinked polystyrene particles [refractive index 1.60, manufactured by Soken Chemical Co., Ltd., 30% toluene dispersion, used after dispersion for 20 minutes at 10,000 rpm with a Polytron disperser]
Crosslinked acrylic-styrene particles: average particle size 3.5 μm [refractive index 1.55, manufactured by Soken Chemical Co., Ltd., 30% toluene dispersion, used after dispersion for 20 minutes at 10,000 rpm with a Polytron disperser]
-FP-13 fluorine-based surface modifier:

(Preparation of sol solution a)
In a 1,000 ml reaction vessel equipped with a thermometer, a nitrogen inlet tube, and a dropping funnel, 187 g (0.80 mol) of acryloxyoxypropyltrimethoxysilane, 27.2 g (0.20 mol) of methyltrimethoxysilane, 320 g of methanol ( 10 mol) and 0.06 g (0.001 mol) of KF were added, and 15.1 g (0.86 mol) of water was slowly added dropwise at room temperature with stirring. After completion of the dropwise addition, the mixture was stirred at room temperature for 3 hours, and then heated and stirred for 2 hours under methanol reflux.
Then, 120 g of sol liquid a was obtained by depressurizingly distilling a low boiling point and further filtering. As a result of GPC measurement of the substance thus obtained, the mass average molecular weight was 1,500, and among the components higher than the oligomer component, the component having a molecular weight of 1,000 to 20,000 was 30%.

Thus, a polarizing plate protective film 402 with a low moisture permeability barrier layer was produced. The moisture permeability of the produced polarizing plate protective film 402 was 33 g / (m ² · day).

<Preparation of polarizing plate>
One surface of the optical film 401 and the polarizing plate protective film 402 produced above (side on which the low moisture-permeable layer was not applied) was subjected to alkali saponification treatment. It was immersed in a 1.5 N aqueous sodium hydroxide solution at 55 ° C. for 2 minutes, washed in a water bath at room temperature, and neutralized with 0.1 N sulfuric acid at 30 ° C. Again, it was washed in a water bath at room temperature and further dried with hot air at 100 ° C. Subsequently, a roll-shaped polyvinyl alcohol film having a thickness of 80 μm was continuously stretched 5 times in an iodine aqueous solution and dried to obtain a polarizing film having a thickness of 20 μm. Using the 3% aqueous solution of polyvinyl alcohol (Kuraray PVA-117H) as an adhesive, the alkali saponified optical film 401 and the protective film 402 for polarizing plate similarly alkali saponified are treated with the saponified surface on the polarizing film side. In this way, a polarizing plate 401 was obtained with a polarizing film interposed therebetween. Under the present circumstances, it affixed so that MD direction of a polymer film might become parallel to the absorption axis of a polarizing film.
Further, the retardation film C-1 was attached to one surface of HLC2-5618 manufactured by Sanlitz Co., Ltd., which is a commercially available polarizing plate using an adhesive, to produce a polarizing plate C-1. .

<Mounting on VA panel>
On the lower polarizing plate (backlight side) of the liquid crystal display device using the vertical alignment type liquid crystal cell of Example 1, the polarizing plate 401 was placed so that the cellulose acylate film 401 was on the liquid crystal cell side. The above polarizing plate C-1 was used for the upper polarizing plate (observer side) so that the retardation film C-1 was on the liquid crystal cell side. The upper polarizing plate and the lower polarizing plate were attached to the liquid crystal cell via an adhesive. The crossed nicols were arranged so that the transmission axis of the upper polarizing plate was in the vertical direction and the transmission axis of the lower polarizing plate was in the horizontal direction.

  As in Example 1, the liquid crystal panel using the optical film of the present invention can achieve neutral black display in both the front direction and the viewing angle direction.

[Example 5]
(Preparation of optical film 501)
<Synthesis of Cyclic Polyolefin Polymer P-1>
100 parts by mass of purified toluene and 100 parts by mass of norbornene carboxylic acid methyl ester were charged into a reaction kettle. Next, ethylhexanoate-Ni 25 mmol% (based on monomer mass) dissolved in toluene, tri (pentafluorophenyl) boron 0.225 mol% (based on monomer mass), and triethylaluminum 0.25 mol% (based on monomer mass) dissolved in toluene ) Was charged into the reaction kettle. The reaction was allowed to proceed for 18 hours at room temperature with stirring. After completion of the reaction, the reaction mixture was put into excess ethanol to produce a copolymer precipitate. The cyclic polyolefin polymer (P-1) obtained by purifying the precipitate was vacuum dried at 65 ° C. for 24 hours.

[Film Formation of Polymer Film 501]
The following composition was put into a mixing tank and stirred to dissolve each component, and then filtered through a filter paper having an average pore size of 34 μm and a sintered metal filter having an average pore size of 10 μm to prepare a cyclic polyolefin polymer solution D-1.

―――――――――――――――――――――――――――――――――
Cyclic polyolefin polymer solution D-1
―――――――――――――――――――――――――――――――――
Cyclic polyolefin polymer P-1 150 parts by mass Exemplary compound (4) of general formula (I) 6.0 parts by mass Dichloromethane 380 parts by mass Methanol 70 parts by mass ――――――――――――――― ―――――――――――――――――

  Next, the following composition containing the cyclic polyolefin polymer solution D-1 produced by the above method was charged into a disperser to prepare a mat agent dispersion M-1.

――――――――――――――――――――――――――――――――――
Matting agent dispersion M-1
――――――――――――――――――――――――――――――――――
Silica particles having an average primary particle size of 16 nm (aerosil R972, manufactured by Nippon Aerosil Co., Ltd.) 2 parts by mass Dichloromethane 73 parts by mass Methanol 10 parts by mass Cyclic polyolefin polymer solution D-1 10 parts by mass ――――――――― ――――――――――――――――――――――――

100 parts by mass of the cyclic polyolefin polymer solution D-1 and 1.43 parts by mass of the matting agent dispersion M-1 were mixed to prepare a dope for film formation.
The above dope was cast at a production rate of 20 m / min using a band casting machine. A film peeled off from the band with a residual solvent amount of about 25% by mass was stretched in the width direction at a stretch rate of 12% using a tenter, and hot air was applied while holding the film so as not to cause wrinkles. Dried. Then, the tenter transport was shifted to the roll transport, and further dried at 120 to 140 ° C. and wound up. In this way, a polymer film 501 having a film thickness of 60 μm was obtained.

  The exemplified compound (4) of the general formula (I) exhibited a nematic liquid crystal phase in a temperature range of 220 ° C to 300 ° C.

(Film surface treatment)
The both sides of the polymer film 501 were imparted hydrophilicity by corona discharge manufactured by Kasuga Electric Co., Ltd. under the condition of 12 W · min / m ² .
<Re, Rth at film wavelengths of 450, 550 and 650 nm>
Re and Rth at wavelengths 450, 550, and 650 nm of the optical film 501 were measured with a KOBRA 21ADH (manufactured by Oji Scientific Instruments) birefringence meter according to the method described above. The results are shown in Table 5.
Re and Rth of the polymer film 501 were satisfactory satisfying the above formulas (A) to (D).

<Preparation of polarizing plate>
(Preparation of adhesive)
10 parts of polyester urethane (Mitsui Takeda Chemicals, Takelac XW-74-C154) and 1 part of isocyanate crosslinking agent (Mitsui Takeda Chemicals, Takenate WD-725) are dissolved in water and the solid content is 20%. A solution adjusted to 1 was prepared. This was used as an adhesive.

(Preparation of polarizing plate)
After the adhesive solution is applied to both surfaces of the polarizer, the polymer film 501 and the saponified Fuji Tac TD80 prepared above are placed so that the polymer film surface is in contact with the polarizing film so as to sandwich the polarizer. Then, they were dried and cured in an oven at 40 ° C. for 72 hours to prepare a polarizing plate 501.

<Mounting on VA panel>
As the upper polarizing plate (observer side) of the liquid crystal display device using the same vertical alignment type liquid crystal cell as in Example 1, a commercially available super high contrast product (HLC2-5618 manufactured by Sanlitz Co., Ltd.) was used. A polarizing plate 501 was installed on the lower polarizing plate (backlight side) so that the polymer film 501 was on the liquid crystal cell side. The upper polarizing plate and the lower polarizing plate were attached to the liquid crystal cell via an adhesive. The crossed nicols were arranged so that the transmission axis of the upper polarizing plate was in the vertical direction and the transmission axis of the lower polarizing plate was in the horizontal direction.

  As in Example 1, the liquid crystal panel using the optical film of the present invention can achieve neutral black display in both the front direction and the viewing angle direction.

[Example 6]
According to the above method, the absorption wavelength (nm) derived from Mx of the low molecular weight compound used in Examples 1 to 5, the absorption wavelength (nm) derived from My, and the angle (°) between My and the molecular major axis And | My | / | Mx | are shown in Table 6 below.

  From Table-6, the low molecular weight compound used in the present invention has an absorption wavelength (nm) derived from My that is longer than the absorption wavelength (nm) derived from Mx, and the transition electron dipole moment My of the long wave component is a molecule. Since it is substantially orthogonal to the major axis direction and the value of | My | / | Mx | is larger than 1, it can be seen that | My | is larger than | Mx |.

  INDUSTRIAL APPLICABILITY According to the present invention, a cellulose acylate film, particularly for VA and OCB modes, which improves the color shift depending on the viewing angle direction during high-contrast and black display, accurately compensated optically by the liquid crystal cell, and a method for producing the same A polarizing plate using the cellulose acylate film is provided.

It is an example of the section schematic diagram of the polarizing plate of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Polarizer 14 Protective film 15 Optically anisotropic layer 16 Protective film 16 'Protective film

Claims (16)

An optical film comprising at least one compound represented by the following general formula (I) and at least one Rth increasing agent.
Formula (I)

(In the general formula (I), L ₁ and L ₂ each represent a single bond or a divalent linking group. A ₁ and A ₂ are —O— and —NR— (R is a hydrogen atom or a substituent). R ₂ and R ₃ each represent a cyclohexane ring having a 4-alkylcyclohexyl group at the 4-position as a substituent, R ₁ and R _4. And R ₅ represents a substituent, and n represents an integer of 0 to 2.) 2. The optical film according to claim 1, comprising at least one compound selected from compounds represented by the following general formula (II), (III), (IV), or (V).
Formula (II)

(In the general formula (II), each R ¹² independently represents an aromatic ring or a heterocyclic ring having a substituent in at least one of the ortho position, the meta position and the para position. X ¹¹ each independently represents Represents a single bond or —NR ¹³ —, wherein each R ¹³ independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, an alkenyl group, an aryl group or a heterocyclic group.
Formula (III)

(In the general formula (III), R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ each independently represents a hydrogen atom or a substituent.)
Formula (IV)
Q ⁷¹ -Q ⁷² -OH
(In the general formula (IV), Q ⁷¹ is a nitrogen-containing aromatic heterocyclic ring, Q ⁷² represents an aromatic ring.)
Formula (V):

(In the general formula (V), Q ⁸¹ and Q ⁸² each independently represents an aromatic ring. X ⁸¹ represents NR ⁸¹ (R ⁸¹ represents a hydrogen atom or a substituent), an oxygen atom or a sulfur atom.) 3. The optical film according to claim 1, wherein at least one of the low molecular compound and the Rth increasing agent exhibits a liquid crystal phase in a temperature range of 100 ° C. to 300 ° C. 4. The optical film according to any one of claims 1 to 3 , wherein the following formulas (1) to (3) are satisfied.
Formula (1) Re (550)> 20 nm
Formula (2) 0.5 <Nz <10
Formula (3) −2.5 × Re (550) +300 <Rth (550) <− 2.5 × Re (550) +500
(In the formula, Re (λ) and Rth (λ) are in-plane and out-of-plane retardation (unit: n) measured by incidence of light having a wavelength of λ nm, respectively, and Nz = Rth (550) / Re ( 550) +0.5) The optical film according to any one of claims 1 to 3 , wherein the following expressions (A) to (D) are satisfied.
(A) 0.1 <Re (450) / Re (550) <0.95
(B) 1.03 <Re (650) / Re (550) <1.93
(C) 0.4 <(Re / Rth (450)) / (Re / Rth (550)) <0.95
(D) 1.05 <(Re / Rth (650)) / (Re / Rth (550)) <1.9
(Where Re (λ) is the in-plane retardation value of the film with respect to light of wavelength λ nm, Rth (λ) is the retardation value in the thickness direction of the film with respect to light of wavelength λ nm, and Re / Rth (λ) is the ratio of the in-plane retardation value of the film to the retardation value in the thickness direction with respect to light having a wavelength of λ nm (unit: nm). The optical film according to any one of claims 1 to 5 , wherein the optical film is produced by a production method including a drawing step of drawing a film and a shrinking step of shrinking the film. The optical film according to any one of claims 1 to 6, the optical film is characterized by comprising the cellulose acylate. 8. The optical film according to claim 7, wherein the acyl substituent of cellulose acylate is substantially composed of only an acetyl group, and the total substitution degree thereof is 2.56 to 3.00. When the substitution degree of the hydroxyl group at the 2-position of the glucose unit of the cellulose acylate is DS2, the substitution degree of the hydroxyl group at the 3-position is DS3, and the substitution degree of the hydroxyl group at the 6-position is DS6, the following formula ( 9. The optical film according to claim 7 , wherein the optical film satisfies I) and (II).
Formula (I): 2.0 ≦ (DS2 + DS3 + DS6) ≦ 3.0
Formula (II): DS6 / (DS2 + DS3 + DS6) ≧ 0.315 Acyl substituent substantially acetyl group consisting of at least two kinds selected from a propionyl group and a butanoyl group, any of claims 7-9 in which the total degree of substitution is characterized in that it is a 2.50 to 3.00 2. An optical film according to item 1. The method for producing an optical film according to any one of claims 1 to 10 , further comprising a stretching step for stretching the film and a shrinking step for shrinking the film during the manufacturing step. A polarizing plate having a pair of protective films sandwiching the polarizing film and the polarizing film, that at least one of the protective films is an optical film according to any one of claims 1 to 1 0 A characteristic polarizing plate. The liquid crystal display device characterized by having a polarization plate according to the optical film or the claims 1 2 according to any one of claims 1 to 1 0. Formula (10), a liquid crystal display device according to claim 1 3 further comprising an optically anisotropic layer satisfying (11).
Formula (10) Rt (550) / Re (550)> 10
Formula (11) Rth (650) -Rth (450) <0 The liquid crystal display device according to claim 13, wherein the liquid crystal display device is in a VA mode. The liquid crystal display device according to any one of claims 1 3 to 1 5, characterized in that using the polarizing plate according to the backlight side to claim 1 2.

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