JP2012215687A - Optical film and method for manufacturing the same, polarizing plate and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical film which is excellent in adhesiveness with a polarizer by a conventional alkali saponification method and in which a circular change of color tone observed when incorporated into a liquid crystal display device is improved.SOLUTION: The optical film is composed of three layers of an outer layer, a core layer and an outer layer, in which the core layer contains a (meth)acrylic resin as a main component, and the outer layer contains a humidity dependence-improving agent satisfying the following expression and contains a cellulose acylate as a main component. (ΔRth(rh,3) is a value obtained by subtracting Rth in a relative humidity of 80% from Rth in a relative humidity of 10% of a film to which 3 pts.mass of the humidity dependence-improving agent is added based on 100 pts.mass of a cellulose acetate; and ΔRth(rh,0) is a value obtained by subtracting Rth in a relative humidity of 80% from Rth in a relative humidity of 10% of a cellulose acetate film to which no humidity dependence-improving agent is added.) ΔRth(rh,3)-ΔRth(rh,0)≤-4 nm.

Description

  The present invention relates to an optical film, a manufacturing method thereof, a polarizing plate, and a liquid crystal display device.

  Liquid crystal display devices are widely used as image display devices for TVs, personal computers, and the like because they can be thinned with low power consumption. In recent years, with the spread of liquid crystal display devices, further thinner layers and higher performance have been demanded. A liquid crystal display device is provided with polarizing plates on both sides of a liquid crystal cell, and the polarizing plate has a structure in which both sides of a polarizer on which iodine or dye is adsorbed and oriented are sandwiched between transparent resins. Such transparent resins have the purpose of protecting the polarizer, and cellulose ester films are most commonly used.

As a polarizing plate protective film, a cellulose ester film is widely used because it has a high transmittance and can be immersed in an alkaline aqueous solution to saponify and hydrophilize its surface to achieve excellent adhesiveness with a polarizer. .
Of the two polarizing plate protective films that sandwich the polarizer from both sides, the film used on the liquid crystal cell side has a thin layer that also functions as a retardation film that compensates for the viewing angle of the liquid crystal display device. It has become common from the request. Also in terms of this function, a cellulose ester film capable of providing a phase difference required for viewing angle compensation of a liquid crystal display device has been effectively used.

However, the cellulose ester film has a problem that the characteristics of the film change due to changes in environmental humidity as a characteristic of the material.
In order to solve this problem, a (meth) acrylic resin film such as methyl methacrylate, which has low hygroscopicity and birefringence, has been proposed as a film replacing cellulose ester. (See Patent Document 1). Such (meth) acrylic resin films have been conventionally studied for copolymerization and lamination with other resin layers (for example, see Patent Documents 2 to 5). Patent Documents 2 to 5 describe that (meth) acrylic resins are less colored and have excellent hot water, solvent resistance, weather resistance, impact resistance, and the like, and mechanical strength.

  On the other hand, from the viewpoint of providing a protective film for a polarizing plate with low retardation, less optical distortion, less bright spot foreign matter, less dimensional stability at high humidity, and good adhesion to a glass substrate, A laminated film in which a cellulose resin layer is provided as an outer layer and various resin layers including an acrylic resin are provided as a core layer has been proposed (Patent Document 6). Here, Patent Document 6 describes that when a resin film such as polycarbonate, polyethersulfone, or uniaxial PET is used for a protective film for a polarizing plate, these polymers have insufficient adhesiveness with a polarizer. There is a description that this problem can be solved by using a laminated film having the structure described in the same document. However, Patent Document 6 does not mention whether the acrylic resin has a problem of adhesiveness with a polarizer.

Japanese Patent Laid-Open No. 5-119217 JP 2000-230016 A JP 2001-151814 A JP 2002-120326 A JP 2002-254544 A JP 2001-215331 A

  Therefore, when the present inventors used the (meth) acrylic resin as a single layer as a polarizing plate protective film as it was, the polarizer and the (meth) acrylic resin film were bonded together by a conventional alkali saponification technique. It has been found that there is a problem that the adhesiveness to the child is inferior to that of the cellulose ester film. Therefore, the conventional alkali saponification such as easy adhesion treatment (for example, corona treatment) to improve the adhesion to the polarizer is performed on the film surface, or an adhesive layer is provided using an ultraviolet ray curable adhesive. It has been found that the number of processes increases compared to the method, which causes a decrease in yield, and that a cost problem arises as a method for producing a polarizing plate protective film.

  In response to this situation, the present inventors examined a method of using a film having a laminated structure in which a surface layer made of a cellulose derivative is provided as an outer layer using the (meth) acrylic resin described in Patent Document 6 as a core layer. It was found that when the film described in the literature was used as a polarizing plate protective film, the adhesion with the polarizer was improved by performing the conventional alkali saponification method on the outer layer.

  However, when the present inventors actually incorporated the film described in Patent Document 6 as a polarizing plate protective film into a liquid crystal display device, when the environmental humidity is changed, the liquid crystal display device has a circular shape when observed obliquely. It has been newly found that there is a problem that color changes occur, and it has been found that this new problem needs to be solved.

  The problem to be solved by the present invention is to provide an optical film having excellent adhesion to a polarizer by a conventional alkali saponification technique and improved circular color change observed when incorporated in a liquid crystal display device. Is to provide. Moreover, the subject which this invention tends to solve is providing the manufacturing method excellent in productivity of this optical film.

  As a result of intensive studies by the inventor, a film having a (meth) acrylic resin as a core layer and a cellulose acetate layer as an outer layer at the same time for overcoming bonding with a polarizer is formed. The reason is unknown by using an additive that suppresses a change in retardation value due to a change in humidity, which is a weak point of the above, but was observed when the film described in Patent Document 6 was incorporated in a liquid crystal display device It has been found that the circular color change is remarkably improved. That is, it discovered that the said subject could be solved with the optical film of the following structures. In addition, the present inventors have found a production method excellent in productivity of the optical film, in which the (meth) acrylic resin and cellulose acetate can be simultaneously formed by solution film formation / co-casting method.

一般式（１）中、Ｙはメチン基又は窒素原子を表し；Ｑ^a、Ｑ^b及びＱ^cはそれぞれ、単結合又は２価の連結基を表し；Ｒ^a、Ｒ^b、及びＲ^cはそれぞれ、水素原子、アルキル基、アルケニル基、アルキニル基、アリール基、シアノ基、ハロゲン基又は複素環基を表し、Ｒ^aとＲ^bは連結して環を形成してもよく；Ｘ²は、単結合又は２価の連結基を表し、Ｘ¹は、単結合又は下記２価の連結基群（５）

（各式中、＊側が前記各式で表される化合物中の１，３，５−トリアジン環に置換しているＮ原子との連結部位であり；Ｒ^gはアルキル基、アルケニル基、アルキニル基、アリール基、又は複素環基を表す。）から選択される２価の基を表し；Ｒ¹及びＲ²はそれぞれ、水素原子、アルキル基、アルケニル基、アルキニル基、アリール基又は複素環基を表し、互いに連結して環を形成してもよい。
［５］ 前記湿度依存性改良剤が、下記一般式（１０１）または一般式（１０２）で表される化合物の少なくとも１種であることを特徴とする［１］〜［３］のいずれか一項に記載の光学フィルム。

（一般式（１０１）中、Ｒ_Aはアルキル基、アルケニル基、アルキニル基、複素環基又はアリール基を表す。Ｘ¹⁰¹、Ｘ¹⁰²、Ｘ¹⁰³及びＸ¹⁰⁴はそれぞれ独立に単結合又は２価の連結基を表す。Ｒ¹⁰¹、Ｒ¹⁰²、Ｒ¹⁰³及びＲ¹⁰⁴はそれぞれ独立に水素原子、アルキル基、アルケニル基、アルキニル基、アリール基、アシル基又は複素環基を表す。）

（一般式（１０２）中、Ｒ_B及びＲ_Cはそれぞれ独立にアルキル基、アルケニル基、アルキニル基、複素環基又はアリール基を表す。Ｘ¹⁰⁵及びＸ¹⁰⁶はそれぞれ独立に単結合又は２価の連結基を表す。Ｒ¹⁰⁵及びＲ¹⁰⁶はそれぞれ独立に水素原子、アルキル基、アルケニル基、アルキニル基、アリール基、アシル基又は複素環基を表す。）
［６］ 前記一般式（１０１）または（１０２）におけるＸ¹⁰¹〜Ｘ¹⁰⁶がそれぞれ独立に単結合または下記一般式（１０３）で表される群の中から選ばれることを特徴とする［５］に記載の光学フィルム。
一般式（１０３）

［７］ 前記外層の合計膜厚が２０μｍ以下であることを特徴とする、［１］〜［６］のいずれか一項に記載の光学フィルム。
［８］ 前記コア層の膜厚が１０〜１００μｍであることを特徴とする、［１］〜［７］のいずれか一項に記載の光学フィルム。
［９］ 全膜厚に占める、前記外層の合計膜厚の割合が、２〜４０％であることを特徴とする、［１］〜［８］のいずれか一項に記載の光学フィルム。
［１０］ 光弾性係数の値が−３．０×１０^-12Ｐａ^-1〜３．０×１０^-12Ｐａ^-1であることを特徴とする、［１］〜［９］のいずれか一項に記載の光学フィルム。
［１１］ セルロースアシレートと下記式（Ｉ）を満たす湿度依存性改良剤と有機溶媒を含有するドープ（Ａ）、および（メタ）アクリル系樹脂と有機溶媒を含有するドープ（Ｂ）を、流延基材側から（Ａ）−（Ｂ）−（Ａ）の順番に共流延法により同時に流延基材上に流延する工程を含むことを特徴とする光学フィルムの製造方法。
式（Ｉ） ΔＲｔｈ（３）≦−４ｎｍ
式（Ｉ’） ΔＲｔｈ（３）＝（ΔＲｔｈ（ｒｈ、３）−ΔＲｔｈ（ｒｈ、０）
（式（Ｉ）中、ΔＲｔｈ（ｒｈ、３）はアセチル置換度２．８６のセルロースアセテート１００質量部に対して湿度依存性改良剤を３質量部添加した厚さ５０μｍのフィルムの２５℃、相対湿度１０％におけるＲｔｈから、２５℃、相対湿度８０％におけるＲｔｈを引いた値を表す。ΔＲｔｈ（ｒｈ、０）は、湿度依存性改良剤が添加されていない、アセチル置換度２．８６のセルロースアセテートからなる厚さ５０μｍのフィルムの２５℃、相対湿度１０％におけるＲｔｈから、２５℃、相対湿度８０％におけるＲｔｈを引いた値を表す。Ｒｔｈは波長５９０ｎｍにおけるフィルムの膜厚方向のレターデーション（単位：ｎｍ）を表す。）
［１２］ 前記ドープ（Ｂ）に含まれる前記（メタ）アクリル系樹脂の重量平均分子量が８０万〜２００万であることを特徴とする［１１］に記載の光学フィルムの製造方法。
［１３］ 前記ドープ（Ａ）の流延厚みを、ドープ（Ａ）の乾燥厚みの合計が２０μｍ以下になるように制御することを特徴とする［１１］または［１２］に記載の光学フィルムの製造方法。
［１４］ 前記ドープ（Ａ）の複素粘度η_Aと、前記ドープ（Ｂ）の複素粘度η_Bが、下記式（ＩＩＩ）の関係を満たすように制御することを特徴とする、［１１］〜［１３］のいずれか一項に記載の光学フィルムの製造方法。
式（ＩＩＩ） η_A≦η_B
［１５］ 前記ドープ（Ａ）および前記ドープ（Ｂ）の２５℃における複素粘度がいずれも１０〜８０Ｐａ・ｓであることを特徴とする［１１］〜［１４］のいずれか一項に記載の光学フィルムの製造方法。
［１６］ 前記ドープ（Ａ）の固形分濃度が１５〜２５質量％であることを特徴とする［１１］〜［１５］のいずれか一項に記載の光学フィルムの製造方法。
［１７］ ［１１］〜［１６］のいずれか一項に記載の光学フィルムの製造方法によって製造されたことを特徴とする、光学フィルム。
［１８］ 偏光子と、［１］〜［１０］および［１７］のいずれか一項に記載の光学フィルムを含むことを特徴とする偏光板。
［１９］ ［１］〜［１０］および［１７］のいずれか一項に記載の光学フィルム、または、［１５］に記載の偏光板を含むことを特徴とする液晶表示装置。
［２０］ ＩＰＳ方式であることを特徴とする、［１９］に記載の液晶表示装置。
［２１］ バックライト側偏光板表面とバックライト側のフィルム部材との距離が１０ｍｍ以下であることを特徴とする、［１９］または［２０］に記載の液晶表示装置。 That is, the present invention has the following configuration.
[1] A three-layer structure of outer layer / core layer / outer layer, wherein the core layer includes a (meth) acrylic resin as a main component, and the outer layer includes a humidity dependency improver that satisfies the following formula (I): An optical film comprising cellulose acylate as a main component.
Formula (I) ΔRth (3) ≦ −4 nm
Formula (I ′) ΔRth (3) = (ΔRth (rh, 3) −ΔRth (rh, 0)
(In the formula (I), ΔRth (rh, 3) is a temperature of 25 ° C. of a 50 μm-thick film obtained by adding 3 parts by mass of a humidity dependency improver to 100 parts by mass of cellulose acetate having an acetyl substitution degree of 2.86. Represents a value obtained by subtracting Rth at 25 ° C. and 80% relative humidity from Rth at 10% humidity.ΔRth (rh, 0) is a cellulose having an acetyl substitution degree of 2.86 to which no humidity-dependent improving agent is added. This is a value obtained by subtracting Rth at 25 ° C. and relative humidity of 80% from Rth at 25 ° C. and relative humidity of 10% of a 50 μm-thick film of acetate, where Rth is the retardation in the film thickness direction of the film at a wavelength of 590 nm ( (Unit: nm)
[2] The optical film as described in [1], wherein ΔRth (10% -80%) defined by the following formula (II) is −10 to 5 nm.
Formula (II) ΔRth (10% -80%) = Rth (10%)-Rth (80%)
(In the formula (II), Rth (10%) represents the value of retardation Rth in the film thickness direction at a film wavelength of 590 nm, 25 ° C. and 10% relative humidity. Rth (80%) represents the film wavelength of 590 nm. Represents the value of retardation Rth in the film thickness direction at 25 ° C. and 80% relative humidity.)
[3] The optical film as described in [1] or [2], wherein the (meth) acrylic resin as a main component of the core layer has a weight average molecular weight of 800,000 to 2,000,000.
[4] The optical film as described in any one of [1] to [3], wherein the humidity dependency improving agent is at least one compound represented by the following general formula (1). :

In general formula (1), Y represents a methine group or a nitrogen atom; Q ^a , Q ^b, and Q ^c each represent a single bond or a divalent linking group; R ^a , R ^b , and R ^c each represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a cyano group, a halogen group or a heterocyclic group, R ^a and R ^b may be linked to form a ring; X ² is a single Represents a bond or a divalent linking group, and X ¹ represents a single bond or the following divalent linking group group (5):

(In each formula, the * side is the linking site with the N atom substituted on the 1,3,5-triazine ring in the compound represented by each formula; R ^g is an alkyl group, an alkenyl group, an alkynyl group; Represents a divalent group selected from: R ¹ and R ² each represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group. And may be connected to each other to form a ring.
[5] Any one of [1] to [3], wherein the humidity dependency improving agent is at least one compound represented by the following general formula (101) or general formula (102). An optical film according to item.

(In the general formula (101), R _A represents an alkyl group, an alkenyl group, an alkynyl group, a heterocyclic group or an aryl group. X ¹⁰¹ , X ¹⁰² , X ¹⁰³ and X ¹⁰⁴ are each independently a single bond or a divalent group. And R ¹⁰¹ , R ¹⁰² , R ¹⁰³ and R ¹⁰⁴ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an acyl group or a heterocyclic group.

(In the general formula (102), R _B and R _C each independently represents an alkyl group, an alkenyl group, an alkynyl group, a heterocyclic group or an aryl group. X ¹⁰⁵ and X ¹⁰⁶ each independently represent a single bond or a divalent group. R ¹⁰⁵ and R ¹⁰⁶ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an acyl group or a heterocyclic group.
[6] X ^{101 to} X ¹⁰⁶ in the general formula (101) or (102) are each independently selected from the group represented by a single bond or the following general formula (103) [5] The optical film described in 1.
General formula (103)

[7] The optical film according to any one of [1] to [6], wherein a total film thickness of the outer layer is 20 μm or less.
[8] The optical film according to any one of [1] to [7], wherein the core layer has a thickness of 10 to 100 μm.
[9] The optical film according to any one of [1] to [8], wherein a ratio of a total film thickness of the outer layer to a total film thickness is 2 to 40%.
[10] Any one of [1] to [9], wherein the value of the photoelastic coefficient is −3.0 × 10 ⁻¹² Pa ^{−1 to} 3.0 × 10 ⁻¹² Pa ^−1. An optical film according to item.
[11] Flowing cellulose acylate, a dope (A) containing a humidity dependency improver satisfying the following formula (I) and an organic solvent, and a dope (B) containing a (meth) acrylic resin and an organic solvent. The manufacturing method of the optical film characterized by including the process of casting on a casting base material simultaneously by the co-casting method in the order of (A)-(B)-(A) from the casting base material side.
Formula (I) ΔRth (3) ≦ −4 nm
Formula (I ′) ΔRth (3) = (ΔRth (rh, 3) −ΔRth (rh, 0)
(In the formula (I), ΔRth (rh, 3) is a temperature of 25 ° C. of a 50 μm-thick film obtained by adding 3 parts by mass of a humidity dependency improver to 100 parts by mass of cellulose acetate having an acetyl substitution degree of 2.86. Represents a value obtained by subtracting Rth at 25 ° C. and 80% relative humidity from Rth at 10% humidity.ΔRth (rh, 0) is a cellulose having an acetyl substitution degree of 2.86 to which no humidity-dependent improving agent is added. This is a value obtained by subtracting Rth at 25 ° C. and relative humidity of 80% from Rth at 25 ° C. and relative humidity of 10% of a 50 μm-thick film of acetate, where Rth is the retardation in the film thickness direction of the film at a wavelength of 590 nm ( (Unit: nm)
[12] The method for producing an optical film as described in [11], wherein the (meth) acrylic resin contained in the dope (B) has a weight average molecular weight of 800,000 to 2,000,000.
[13] The optical film of [11] or [12], wherein the casting thickness of the dope (A) is controlled so that the total dry thickness of the dope (A) is 20 μm or less. Production method.
[14] and the complex viscosity eta _A of the dope (A), the complex viscosity eta _B of the dope (B), wherein the controller controls so as to satisfy the relationship of formula (III), [11] ~ [13] The method for producing an optical film according to any one of [13].
Formula (III) η _A ≦ η _B
[15] The complex viscosity at 25 ° C. of the dope (A) and the dope (B) is 10 to 80 Pa · s, as described in any one of [11] to [14] Manufacturing method of optical film.
[16] The method for producing an optical film according to any one of [11] to [15], wherein a solid content concentration of the dope (A) is 15 to 25% by mass.
[17] An optical film manufactured by the method for manufacturing an optical film according to any one of [11] to [16].
[18] A polarizing plate comprising a polarizer and the optical film according to any one of [1] to [10] and [17].
[19] A liquid crystal display device comprising the optical film according to any one of [1] to [10] and [17], or the polarizing plate according to [15].
[20] The liquid crystal display device according to [19], which is an IPS system.
[21] The liquid crystal display device according to [19] or [20], wherein the distance between the backlight-side polarizing plate surface and the backlight-side film member is 10 mm or less.

  According to the present invention, it is possible to provide an optical film that is excellent in adhesiveness with a polarizer by a conventional alkali saponification technique and has improved circular color change observed when incorporated in a liquid crystal display device. it can. Moreover, according to the manufacturing method of this invention, the manufacturing method excellent in productivity of the optical film of this invention can be provided. Further, the liquid crystal display device of the present invention is less likely to cause a circular color change.

It is a schematic diagram which shows an example of a band casting apparatus. It is a schematic diagram which shows an example of a drum casting apparatus.

Hereinafter, the optical film of the present invention and the production method thereof, and the polarizing plate and the liquid crystal display device using the optical film of the present invention will be described in detail.
The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

[Optical film]
The optical film of the present invention (hereinafter also referred to as the film of the present invention) has a three-layer structure of outer layer / core layer / outer layer, the core layer containing a (meth) acrylic resin as a main component, and the outer layer described below. It contains a humidity dependency improving agent that satisfies the formula (I) and contains cellulose acylate as a main component.
Formula (I) ΔRth (3) ≦ −4 nm
Formula (I ′) ΔRth (3) = (ΔRth (rh, 3) −ΔRth (rh, 0)
(In the formula (I), ΔRth (rh, 3) is a temperature of 25 ° C. of a 50 μm-thick film obtained by adding 3 parts by mass of a humidity dependency improver to 100 parts by mass of cellulose acetate having an acetyl substitution degree of 2.86. Represents a value obtained by subtracting Rth at 25 ° C. and 80% relative humidity from Rth at 10% humidity.ΔRth (rh, 0) is a cellulose having an acetyl substitution degree of 2.86 to which no humidity-dependent improving agent is added. This is a value obtained by subtracting Rth at 25 ° C. and relative humidity of 80% from Rth at 25 ° C. and relative humidity of 10% of a 50 μm-thick film of acetate, where Rth is the retardation in the film thickness direction of the film at a wavelength of 590 nm ( (Unit: nm)
Hereinafter, preferred embodiments of the film of the present invention will be described.

<Film layer configuration>
(Outer layer thickness)
The optical film of the present invention has an outer layer containing a humidity dependency improving agent satisfying the following formula (I) on both sides of a core layer containing a (meth) acrylic resin and containing cellulose acylate as a main component. With such a configuration, the film of the present invention has a function of improving adhesiveness with a polarizer and circular color change observed when incorporated in a liquid crystal display device.
The total film thickness of the outer layer containing cellulose acylate is preferably 20 μm or less, more preferably 3 μm to 20 μm or less, particularly preferably 3.5 to 15 μm, more particularly preferably. Is 4-8 μm. Compared to a film in which a thick cellulose acylate film is used as a core layer and a thin acrylic functional layer is applied as a surface layer on the surface, the film of the present invention has a photoelasticity by having a film layer structure having such a thickness. The coefficient can be reduced.

(Core layer thickness)
The optical film of the present invention preferably exhibits a function as a protective film for a polarizer of usually 20 to 40 μm. For this reason, it is preferable that the thickness of the core layer containing (meth) acrylic resin is 10 to 100 μm. More preferably, it is 20-80 micrometers, More preferably, it is 20-60 micrometers, Most preferably, it is 30-60 micrometers.

(Lamination mode)
The film of the present invention has an outer layer made of cellulose acylate on both sides of a core layer containing a (meth) acrylic resin.
More preferably, the film of the present invention has one outer layer on each side of the core layer.

  As for the film of this invention, 10-240 micrometers is preferable, as for the film thickness of the whole optical film as a laminated body, More preferably, it is 10-150 micrometers, Especially preferably, it is 10-100 micrometers, More preferably, it is 20-60 micrometers. It is.

  In the film of the present invention, the ratio of the total film thickness of the outer layer to the total film thickness is preferably 2 to 40%, more preferably 3 to 30%, and more preferably 5 to 20%. It is particularly preferred. However, the total film thickness of an outer layer here means the total film thickness of two layers, when there are two outer layers.

(Film width)
The film of the present invention preferably has a film width of 400 to 2500 mm, more preferably 1000 mm or more, particularly preferably 1500 mm or more, and particularly preferably 1800 mm or more.

Next, details and preferred embodiments of the components contained in each layer of the film of the present invention will be described.
Hereinafter, the configuration of the core layer and the outer layer will be described in order.

<Core layer>
The optical film of the present invention has a core layer containing a (meth) acrylic resin. In this specification, (meth) acrylic resin is a concept including both methacrylic resin and acrylic resin. The (meth) acrylic resin also includes acrylate / methacrylate derivatives, particularly acrylate / methacrylate (co) polymers.

((Meth) acrylic resin)
The repeating structural unit of the (meth) acrylic acid resin is not particularly limited. The (meth) acrylic resin preferably has a repeating structural unit derived from a (meth) acrylic acid ester monomer as a repeating structural unit.

The (meth) acrylic resin further polymerizes at least one selected from a hydroxyl group-containing monomer, an unsaturated carboxylic acid, and a monomer represented by the following general formula (201) as a repeating structural unit. It may contain a repeating structural unit constructed by
Formula (201)
CH ₂ = C (X) R ²⁰¹
(Wherein R ²⁰¹ represents a hydrogen atom or a methyl group, X represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, a —CN group, a —CO—R ²⁰² group, or —O—CO—R; ²⁰³ represents a group, and R ²⁰² and R ²⁰³ represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms.)

The (meth) acrylic acid ester is not particularly limited, and examples thereof include methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, cyclohexyl acrylate, and benzyl acrylate. Acrylic acid esters; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, methacrylic acid esters such as benzyl methacrylate; These may be used alone or in combination of two or more. Among these, methyl methacrylate is particularly preferable from the viewpoint of excellent heat resistance and transparency.
When the (meth) acrylic acid ester is used, the content ratio in the monomer component to be subjected to the polymerization step is preferably 10 to 100% by weight, more preferably 10%, in order to sufficiently exhibit the effects of the present invention. -100% by weight, more preferably 40-100% by weight, particularly preferably 50-100% by weight.

The hydroxyl group-containing monomer is not particularly limited. For example, 2- (hydroxyalkyl) acrylic acid ester such as α-hydroxymethylstyrene, α-hydroxyethylstyrene, methyl 2- (hydroxyethyl) acrylate; 2 2- (hydroxyalkyl) acrylic acid such as-(hydroxyethyl) acrylic acid; and the like. These may be used alone or in combination of two or more.
In the case of using the hydroxyl group-containing monomer, the content ratio in the monomer component to be subjected to the polymerization step is preferably 0 to 30% by weight, more preferably 0 to 0% in order to sufficiently exert the effects of the present invention. It is 20% by weight, more preferably 0 to 15% by weight, particularly preferably 0 to 10% by weight.

Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, crotonic acid, α-substituted acrylic acid, α-substituted methacrylic acid and the like. These may be used alone or in combination of two or more. You may use together. Among these, acrylic acid and methacrylic acid are preferable in that the effects of the present invention are sufficiently exhibited.
When the unsaturated carboxylic acid is used, the content ratio in the monomer component to be subjected to the polymerization step is preferably 0 to 30% by weight, more preferably 0 to 20%, in order to sufficiently exhibit the effects of the present invention. % By weight, more preferably 0-15% by weight, particularly preferably 0-10% by weight.

Examples of the monomer represented by the general formula (201) include styrene, vinyl toluene, α-methyl styrene, acrylonitrile, methyl vinyl ketone, ethylene, propylene, vinyl acetate, and the like. You may use, and may use 2 or more types together. Among these, styrene and α-methylstyrene are particularly preferable in that the effects of the present invention are sufficiently exhibited.
When the monomer represented by the general formula (201) is used, the content ratio in the monomer component to be subjected to the polymerization step is preferably 0 to 30% in order to sufficiently exhibit the effects of the present invention. %, More preferably 0 to 20% by weight, still more preferably 0 to 15% by weight, particularly preferably 0 to 10% by weight.

The monomer component may form a lactone ring after polymerization. In that case, it is preferable to polymerize the monomer component to obtain a polymer having a hydroxyl group and an ester group in the molecular chain.
As a polymerization reaction form for polymerizing the monomer component to obtain a polymer having a hydroxyl group and an ester group in the molecular chain, a polymerization form using a solvent is preferable, and solution polymerization is particularly preferable. .

In the case of a polymerization form using a solvent, the polymerization solvent is not particularly limited. For example, aromatic hydrocarbon solvents such as toluene, xylene, and ethylbenzene; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ether solvents such as tetrahydrofuran Etc., and only one of these may be used, or two or more may be used in combination.
In the production method of the present invention, the (meth) acrylic resin is dissolved in an organic solvent and the solution is cast to form the core layer. Therefore, the organic solvent at the time of synthesizing the (meth) acrylic resin is: It is not limited as compared with the case where melt film formation is performed, and synthesis may be performed using an organic solvent having a high boiling point.

During the polymerization reaction, a polymerization initiator may be added as necessary. Although it does not specifically limit as a polymerization initiator, For example, cumene hydroperoxide, diisopropylbenzene hydroperoxide, di-t-butyl peroxide, lauroyl peroxide, benzoyl peroxide, t-butylperoxyisopropyl carbonate, t-amyl Organic peroxides such as peroxy-2-ethylhexanoate; 2,2′-azobis (isobutyronitrile), 1,1′-azobis (cyclohexanecarbonitrile), 2,2′-azobis (2, Azo compounds such as 4-dimethylvaleronitrile), and the like. These may be used alone or in combination of two or more. The amount of the polymerization initiator used is not particularly limited as long as it is appropriately set according to the combination of the monomers used and the reaction conditions.
The weight average molecular weight of the polymer can be adjusted by adjusting the amount of the polymerization initiator.

  When performing the polymerization, it is preferable to control the concentration of the produced polymer in the polymerization reaction mixture to be 50% by weight or less in order to suppress gelation of the reaction solution. Specifically, when the concentration of the produced polymer in the polymerization reaction mixture exceeds 50% by weight, it is preferable that the polymerization solvent is appropriately added to the polymerization reaction mixture and controlled to be 50% by weight or less. . The concentration of the produced polymer in the polymerization reaction mixture is more preferably 45% by weight or less, still more preferably 40% by weight or less.

  The form in which the polymerization solvent is appropriately added to the polymerization reaction mixture is not particularly limited, and the polymerization solvent may be added continuously or intermittently. By controlling the concentration of the produced polymer in the polymerization reaction mixture in this way, the gelation of the reaction solution can be more sufficiently suppressed. The polymerization solvent to be added may be the same type of solvent used during the initial charging of the polymerization reaction or may be a different type of solvent, but is the same as the solvent used during the initial charging of the polymerization reaction. It is preferable to use different types of solvents. Further, the polymerization solvent to be added may be only one type of solvent or a mixed solvent of two or more types.

  The weight average molecular weight of the polymer having a hydroxyl group and an ester group in the molecular chain obtained by polymerizing the monomer component obtained in the polymerization step is preferably 800,000 to 2,000,000, more than 1,000,000 and less than 2,000,000. The range is more preferable, and the range of more than 1 million and 1.8 million or less is particularly preferable.

  The (meth) acrylic resin is provided with an outer layer mainly composed of cellulose acylate on both sides of the core layer of the (meth) acrylic resin having a weight average molecular weight (sometimes referred to as a mass average molecular weight). Although there is no restriction | limiting in the combination of both weight average molecular weight, A weight average molecular weight can be suitably selected so that it may become the optimal in the process of film forming.

Here, an acrylic resin having a molecular weight of about 100,000 is generally used for film formation. Specifically, it is impossible in the first place to form a high molecular weight acrylic resin film by melt film formation. An acrylic resin film can also be formed by solution casting, but in that case, it is necessary to prepare a dope having a viscosity that facilitates solution casting. If the acrylic resin has a molecular weight of 300,000 or more, it is easy to prepare a dope having high casting suitability, and such an acrylic resin has been conventionally used for film formation.
In contrast, the optical film of the present invention is preferably formed using an acrylic resin having a larger weight average molecular weight in order to realize co-casting with the outer layer of cellulose acylate. That is, the (meth) acrylic resin used in the optical film of the present invention has a weight average molecular weight (Mw) in the range of 800,000 to 2,000,000, particularly from the viewpoint of brittleness and self-film-forming properties as an optical film. From the viewpoint of solution casting suitability, it is more preferably in the range of greater than 1 million to 2 million, and particularly preferably in the range of greater than 1 million to 1.8 million.
The weight average molecular weight of the (meth) acrylic resin can be measured by gel permeation chromatography.
The (meth) acrylic resin is particularly preferably a (meth) acrylic resin having a weight average molecular weight of 800,000 to 2,000,000 and having 50% by mass or more of methyl methacrylate units in the molecule.

  The (meth) acrylic resin has a glass transition temperature (Tg) of preferably 90 ° C. or higher, more preferably 100 ° C. or higher, and further preferably 110 ° C. or higher.

(Other thermoplastic resins that may be included in the core layer)
The core layer in the present invention may contain a thermoplastic resin other than the (meth) acrylic resin. Other thermoplastic resins are not particularly limited as long as they do not violate the gist of the present invention, but thermoplastic resins that are thermodynamically compatible are preferable in terms of improving transparency and mechanical strength.

  Examples of the other thermoplastic resins include olefin polymers such as polyethylene, polypropylene, ethylene-propylene copolymer, and poly (4-methyl-1-pentene); halogen-containing polymers such as vinyl chloride and chlorinated vinyl resins. Polymer; Acrylic polymer such as polymethyl methacrylate; Styrene polymer such as polystyrene, styrene-methyl methacrylate copolymer, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene block copolymer; polyethylene terephthalate, polybutylene Polyesters such as terephthalate and polyethylene naphthalate; polyamides such as nylon 6, nylon 66, nylon 610; polyacetal; polycarbonate; polyphenylene oxide; polyphenylene sulfide; Polyetheretherketone; polysulfone; polyether sulfone; polyoxyethylene benzylidene alkylene; polyamideimide; polybutadiene rubber, rubber-like polymer such as ABS resin or ASA resin containing an acrylic rubber; and the like. The rubbery polymer preferably has a graph collar portion having a composition compatible with the lactone ring polymer of the present invention on the surface, and the average particle diameter of the rubbery polymer is transparency when formed into a film. From the viewpoint of improvement, it is preferably 100 nm or less, and more preferably 70 nm or less.

  Thermoplastic resins that are thermodynamically compatible with (meth) acrylic resins include copolymers containing vinyl cyanide monomer units and aromatic vinyl monomer units, specifically acrylonitrile- A polymer containing 50% by weight or more of a styrene copolymer, a polyvinyl chloride resin, or a methacrylic acid ester may be used. Among them, when an acrylonitrile-styrene copolymer is used, the core layer having a glass transition temperature of 120 ° C. or more, a phase difference per 100 μm in the plane direction of 20 nm or less, and a total light transmittance of 85% or more can be easily obtained. Can be obtained.

  When the core layer in the present invention contains the other thermoplastic resin, the content ratio of the (meth) acrylic resin and the other thermoformable resin is preferably 60 to 99: 1 to 40% by weight. Preferably it is 70-97: 3-30 weight%, More preferably, it is 80-95: 5-20 weight%. However, it is preferable that the core layer in the invention does not contain the other thermoplastic resin from the viewpoint of improving the circular color change in the lick direction of the liquid crystal display device of the invention.

(Residual solvent amount)
The film of the present invention is preferably formed by co-casting by the production method of the present invention described later. Thus, by forming the core layer containing the (meth) acrylic resin by solution casting, the surface of the outer layer is more than when the layer containing the (meth) acrylic resin is formed by melt casting. The condition can be improved.

<Outer layer>
Next, the outer layer of the film of the present invention will be described.
The film of the present invention includes an outer layer containing a humidity dependency improving agent satisfying the formula (I) and containing cellulose acylate as a main component.

(Thickness)
The preferred embodiment of the thickness of the outer layer is as described above in the description of the layer structure of the present invention.

(Cellulose acylate)
The cellulose acylate used in the present invention is not particularly defined. Examples of the raw material cellulose include cotton linter and wood pulp (hardwood pulp, conifer pulp). Cellulose acylate obtained from any raw material cellulose can be used, and in some cases, it may be mixed and used. Detailed descriptions of these raw material celluloses can be found, for example, by Marusawa and Uda, “Plastic Materials Course (17) Fibrous Resin”, published by Nikkan Kogyo Shimbun (published in 1970), and the Japan Institute of Invention and Technology Publication No. 2001 The cellulose described in No.-1745 (pages 7 to 8) can be used.

The cellulose acylate used in the present invention preferably has a total substitution degree of acyl groups of 1.2 or more and 3.0 or less.
Furthermore, the cellulose acylate used in the present invention has a total substitution degree of acyl groups of TA, a substitution degree of acyl groups having 2 carbon atoms, TA2, and a substitution degree of acyl groups of 3 to 7 carbon atoms. When TA3 is satisfied, the following conditions are preferably satisfied. By setting it as the following ranges, an optical film excellent in terms of adhesion to an adjacent layer, peelability from a support during casting, and curl reduction of the film can be obtained.
2.2 ≦ TA total ≦ 3.0
1.5 ≦ TA2 ≦ 3.0
0.0 ≦ TA3 ≦ 0.7

The cellulose acylate is more preferably a cellulose acylate resin that satisfies the following conditions.
2.5 ≦ TA total ≦ 3.0
2.4 ≦ TA2 ≦ 3.0
0.0 ≦ TA3 ≦ 0.1
More preferably, TA2, that is, the degree of acetyl substitution is 2.8 to 2.94. The cellulose acylate particularly preferably has a total TA of 2.8 to 2.94, and TA3 is particularly preferably 0. The cellulose acylate is more particularly preferably cellulose acetate having an acetyl substitution degree of 2.8 to 2.94.

  The cellulose acylate used in the present invention is preferably at least one selected from cellulose acetate, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate benzoate, cellulose propionate, and cellulose butyrate. Among these, more preferred cellulose acylates are cellulose acetate and cellulose acetate propionate, and more preferred is cellulose acetate.

  In addition, the substitution degree of an acetyl group and the substitution degree of other acyl groups can be obtained by a method prescribed in ASTM-D817-96.

  The weight average molecular weight (Mw) of the cellulose acylate used in the present invention is preferably 75000 or more, more preferably in the range of 75,000 to 300,000, particularly from the viewpoint of adhesion to an acrylic resin. It is more preferable that it is within the range of 240,000, and that of 160000 to 240000 is particularly preferable. If the weight average molecular weight (Mw) of the cellulose acylate is 75000 or more, the effect of improving the self-film forming property and adhesion of the cellulose acylate resin layer itself is preferable. In the present invention, two or more kinds of cellulose acylate resins can be mixed and used.

(Humidity dependency improver)
The optical film of the present invention is characterized in that the outer layer contains a humidity dependency improving agent having ΔRth (3) defined by the following formula (I) of −4 nm or less.
In the present invention, the “humidity dependency improving agent” refers to an agent that, when added to a polymer film, can reduce fluctuations in Rth depending on the humidity of the polymer film. Specifically, an additive-free polymer film and a sample-added polymer film were prepared, and Rth when the humidity was adjusted for 12 hours at 25 ° C. and 10% relative humidity, and 25 ° C. and relative humidity 80, respectively. % Rth when humidity is adjusted for 12 hours, and compared. When the variation in Rth is smaller in the polymer film to which the sample is added than in the polymer film to which no sample is added, the sample is referred to as a humidity dependency improver.

Formula (I) ΔRth (3) ≦ −4 nm
Formula (I ′) ΔRth (3) = (ΔRth (rh, 3) −ΔRth (rh, 0)
(In the formula (I), ΔRth (rh, 3) is a temperature of 25 ° C. of a 50 μm-thick film obtained by adding 3 parts by mass of a humidity dependency improver to 100 parts by mass of cellulose acetate having an acetyl substitution degree of 2.86. Represents a value obtained by subtracting Rth at 25 ° C. and 80% relative humidity from Rth at 10% humidity.ΔRth (rh, 0) is a cellulose having an acetyl substitution degree of 2.86 to which no humidity-dependent improving agent is added. This is a value obtained by subtracting Rth at 25 ° C. and relative humidity of 80% from Rth at 25 ° C. and relative humidity of 10% of a 50 μm-thick film of acetate, where Rth is the retardation in the film thickness direction of the film at a wavelength of 590 nm ( (Unit: nm)
When such a compound is used for the outer cellulose acylate layer, a circular color change can be remarkably suppressed when the obtained film is incorporated in a liquid crystal display device as a polarizing plate protective film.
Further, by using a humidity-dependent improving agent having a smaller ΔRth (3), ΔRth can be effectively reduced even with a small addition amount, so that the total amount of the additive relative to the cellulose ester can be reduced. It is possible to suppress the volatilization of the additive during the film forming process, improve the transportability of the film, and suppress the bleed out of the film.

Examples of the compound that can serve as the humidity dependency improver include a compound having a hydrogen bonding group and a high density of hydrogen bonding groups per molecular weight.
The hydrogen bonding group is preferably a group containing at least one —OH group or —NH group. For example, a hydroxyl group (—OH), a carboxyl group (—COOH), a carbamoyl group (—CONHR) , Sulfamoyl group (—SONHR), ureido group (—NHCONHR), amino group (—NHR), urethane group (—NHCOOR), and amide group (—NHCOR) are more preferable (where R is a hydrogen atom, a hydroxy group, an amino group, Group, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 15 carbon atoms or a heterocyclic group, preferably a hydrogen atom). More preferred are an amino group, a hydroxyl group, a carboxyl group, a carbamoyl group, a sulfamoyl group or a ureido group, and even more preferred are an amino group and a hydroxyl group. It is further preferred that at least one of the hydroxyl groups is a phenolic hydroxyl group.
Examples of the humidity dependency improver for the retardation include (1) a compound represented by the following general formula (1), (2) a compound represented by the following general formula (101) or (102), and (3) hydroxyl. Examples include a compound containing a group. Among them, (1) a compound represented by the following general formula (1) or (2) a compound represented by the following general formula (101) or (102) is preferable, and (1) the following general formula (1) The compound represented by these is more preferable.
Hereinafter, (1) a compound represented by the following general formula (1), (2) a compound represented by the following general formula (101) or (102), and (3) a compound containing a hydroxyl group in this order. Each preferred embodiment of the compound that is preferably used as a property improving agent will be described.

(1) Compound Represented by General Formula (1) The polymer film of the present invention preferably contains at least one compound represented by the following general formula (1). In addition, in a polymer film containing a hydrophilic polymer, particularly a polymer having a hydroxyl group as a main component, fluctuations in Re and Rth tend to be remarkable due to changes in humidity in the use environment. The compound represented by the formula (1) has an action of reducing the variation of Rth accompanying the humidity change of the use environment, that is, it acts as a humidity dependency improving agent for polymer films. In addition, it is also preferable that the compound represented by the following general formula (1) has an effect of increasing Re and / or Rth of the polymer film, that is, acts as a retardation increasing agent.

Furthermore, the compound represented by the following general formula (1) is excellent in stability in a state dissolved in an organic solvent, and the use of these compounds is the production of a polymer film, particularly by the solution casting method. It also contributes to the improvement of stability.
Hereinafter, the following general formula (1) and general formula (2) which is a preferred example thereof will be described in detail. In the present specification, the terms “alkyl group”, “alkenyl group”, and “alkynyl group” are used to mean both linear and branched chains.

In general formula (1), Y represents a methine group or a nitrogen atom; Q ^a , Q ^b, and Q ^c each represent a single bond or a divalent linking group; R ^a , R ^b , and R ^c each represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a cyano group, a halogen group or a heterocyclic group, R ^a and R ^b may be linked to form a ring; X ² is a single Represents a bond or a divalent linking group, X ¹ represents a single bond or a divalent group selected from the divalent linking group group (5) described later; R ¹ and R ² are each a hydrogen atom, It represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and may be linked to each other to form a ring.

Each symbol in the general formula (2) has the same meaning as in the general formula (1); X ⁴ represents a single bond or a divalent linking group, and X ³ represents a single bond or a divalent group described later. R ³ and R ⁴ each represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and are connected to each other. To form a ring.

  In the general formulas (1) and (2), when Y is a methine group, the 6-membered ring in the formula is a pyridine ring, and when Y is -N-, the 6-membered ring in the formula is a pyrimidine. It is a ring.

In the general formulas (1) and (2), examples of the divalent linking group represented by Q ^a , Q ^b, and Q ^c include —O—, —S—, —N (X ^a —R ^h ) —. ^{, -N (X a -R h)} -X b - include divalent linking group represented by. Here, X ^a and X ^b each represent a single bond or a divalent linking group. Examples of the divalent linking group represented by X ^a and X ^b include —CO—, —COO—, and —CONH—. R ^h is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkynyl group having 2 to 8 carbon atoms, an aryl group having 6 to 10 carbon atoms, or the number of carbon atoms Represents 2 to 10 heterocyclic groups. Preferable examples of the divalent linking group each represented by Q ^a , Q ^b and Q ^c include a single bond, —O—, —N (Xa—Rh) — and —N (Xa—Rh) —Xb—. Single bonds, —O—, —NH—, and —NH—Xb— are particularly preferred. Preferred examples of —NH—Xb— include —NH—CO—, —NH—COO—, —NH—CONH—, —NH—SO ₂ —, etc., —NH—CO—, —NH—COO -Is more preferable.

In the general formulas (1) and (2), R ^a , R ^b and R ^c each represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a cyano group, a halogen group or a heterocyclic group, ^a and R ^b may combine to form a ring.
When R ^a , R ^b and R ^c are each an alkyl group, it is preferably 1 to 20 carbon atoms, more preferably 1 to 8 carbon atoms, and 1 to 4 carbon atoms. Is particularly preferred. When R ^a , R ^b, and R ^c are each an alkyl group, one or two or more carbon atoms that are not adjacent to each other are an oxygen atom, a sulfur atom, and a nitrogen atom (—NH— or —N (R) — (R is an alkyl group) and may be substituted with a heteroatom selected from. For example, each of R ^a , R ^b and R ^c may be an alkylene (eg, ethylene, propylene) oxy group.
When R ^a , R ^b and R ^c are each an alkenyl group, it is preferably 2 to 20 carbon atoms, more preferably 2 to 8 carbon atoms, and 2 to 4 carbon atoms. Is particularly preferred.
When R ^a , R ^b and R ^c are each an alkynyl group, it is preferably 2 to 20 carbon atoms, more preferably 2 to 8 carbon atoms, and 2 to 4 carbon atoms. Is particularly preferred.

When R ^a , R ^b and R ^c are each an aryl group, it is preferably 6 to 24 carbon atoms, more preferably 6 to 18 carbon atoms, and 6 to 10 carbon atoms. Is particularly preferable from the viewpoint of improving humidity dependency. Specifically, a benzene ring and a naphthalene ring are preferable, and a benzene ring is particularly preferable.
When R ^a , R ^b and R ^c are each a heterocyclic group, it is preferably 4 to 20 carbon atoms, more preferably 4 to 10 carbon atoms, and 4 to 6 carbon atoms. It is particularly preferable from the viewpoint of improving humidity dependency. Specific examples include a pyrrolyl group, a pyrrolidino group, a pyrazolyl group, a pyrazolidino group, an imidazolyl group, a piperazino group, and a morpholino group.

R ^a and R ^b may be linked to form a ring. The ring formed may be a hydrocarbon ring or a heterocyclic ring. It is preferably a 5-membered ring or a 6-membered ring.

Each of R ^a , R ^b, and R ^c may further have one or more substituents and may not have one, if possible. Examples of the substituent that each of R ^a , R ^b, and R ^c may have include the following substituent group T.
Substituent group T:
An alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms such as a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, an n-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl, cyclohexyl group, etc.), alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12, more preferably 2 to 8). For example, a vinyl group, an allyl group, a 2-butenyl group, a 3-pentenyl group, etc.), an alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 2 carbon atoms). 8 such as propargyl group and 3-pentynyl group), aryl group (preferably having 6 to 30 carbon atoms, more preferred) 6 to 20, particularly preferably 6 to 12, and examples thereof include a phenyl group, a biphenyl group, and a naphthyl group.), An amino group (preferably having 0 to 20 carbon atoms, more preferably 0 to 10, Particularly preferably 0 to 6, for example, amino group, methylamino group, dimethylamino group, diethylamino group, dibenzylamino group, etc.), alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12, particularly preferably 1 to 8, for example, methoxy group, ethoxy group, butoxy group, etc.), aryloxy group (preferably 6-20 carbon atoms, more preferably 6-16, particularly Preferably they are 6-12, for example, a phenyloxy group, 2-naphthyloxy group etc. are mentioned), an acyl group (preferably carbon atom number). To 20, more preferably 1 to 16, particularly preferably 1 to 12, and examples thereof include an acetyl group, a benzoyl group, a formyl group, and a pivaloyl group), an alkoxycarbonyl group (preferably having 2 to 20 carbon atoms). , More preferably 2 to 16, particularly preferably 2 to 12, and examples thereof include a methoxycarbonyl group and an ethoxycarbonyl group.), An aryloxycarbonyl group (preferably having 7 to 20 carbon atoms, more preferably 7). -16, particularly preferably 7-10, for example, phenyloxycarbonyl group, etc.), acyloxy groups (preferably 2-20 carbon atoms, more preferably 2-16, particularly preferably 2-10). For example, acetoxy group, benzoyloxy group, etc.), acylamino group (preferably The number of carbon atoms is 2 to 20, more preferably 2 to 16, particularly preferably 2 to 10, and examples thereof include an acetylamino group and a benzoylamino group. ), An alkoxycarbonylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms such as a methoxycarbonylamino group), an aryloxycarbonylamino group ( Preferably it has 7 to 20 carbon atoms, more preferably 7 to 16 and particularly preferably 7 to 12, and examples thereof include a phenyloxycarbonylamino group, and a sulfonylamino group (preferably 1 to 20 carbon atoms). More preferably, it is 1-16, Most preferably, it is 1-12, for example, a methanesulfonylamino group, a benzenesulfonylamino group, etc.), a sulfamoyl group (preferably C0-20, more preferably 0). To 16, particularly preferably 0 to 12, such as sulfamoyl group, methyl Rufamoyl group, dimethylsulfamoyl group, phenylsulfamoyl group, etc.), carbamoyl group (preferably 1-20 carbon atoms, more preferably 1-16, particularly preferably 1-12, for example, Carbamoyl group, methylcarbamoyl group, diethylcarbamoyl group, phenylcarbamoyl group, etc.), alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16, particularly preferably 1 to 12, Methylthio group, ethylthio group, etc.), arylthio group (preferably 6-20 carbon atoms, more preferably 6-16, particularly preferably 6-12, such as phenylthio group). A sulfonyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16, Is preferably 1 to 12, for example, mesyl group, tosyl group, etc.), sulfinyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16, particularly preferably 1 to 12, For example, a methanesulfinyl group, a benzenesulfinyl group, etc.), a ureido group (preferably 1-20 carbon atoms, more preferably 1-16, particularly preferably 1-12, for example, a ureido group, a methylureido group). , Phenylureido groups, etc.), phosphoric acid amide groups (preferably having 1-20 carbon atoms, more preferably 1-16, particularly preferably 1-12, such as diethylphosphoric acid amide, phenylphosphoric acid Amide, etc.), 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, heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms). A hetero atom such as a nitrogen atom, an oxygen atom, a sulfur atom, specifically an imidazolyl group, a pyridyl group, a quinolyl group, a furyl group, a piperidyl group, a morpholino group, a benzoxazolyl group, a benzimidazolyl group, Examples thereof include a benzthiazolyl group. ) And a silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms such as a trimethylsilyl group and a triphenylsilyl group).
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.

In general formulas (1) and (2), each of R ^a and R ^b is preferably ^a hydrogen atom or a substituted or unsubstituted alkyl group. In general formula (1), R ^c is preferably a hydrogen atom, or a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group.

However, examples of the general formula (1) and the compound represented by (2), Y is a nitrogen atom, and, -Q ^a -R ^a and -Q ^c -R ^c, respectively, -OH and Compounds that are groups other than —SH are included.

In the general formulas (1) and (2), R ¹ , R ² , R ³ and R ⁴ each represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, A ring may be formed.
When R ¹ , R ² , R ³ and R ⁴ are each an alkyl group, it is preferably 1 to 20 carbon atoms, more preferably 1 to 8 carbon atoms, and 1 to 4 carbon atoms. It is particularly preferred that Note that when R ¹ , R ² , R ^3, and R ⁴ are each an alkyl group, one or two or more non-adjacent carbon atoms are an oxygen atom, a sulfur atom, and a nitrogen atom (—NH— or —N ( R) — (R represents an alkyl group) may be substituted with a heteroatom selected from. For example, R ¹ , R ² , R ³ and R ⁴ may be an alkylene (eg, ethylene, propylene) oxy group.
When R ¹ , R ² , R ³ and R ⁴ are each an alkenyl group, it is preferably 2 to 20 carbon atoms, more preferably 2 to 8 carbon atoms, and 2 to 4 carbon atoms. It is particularly preferred that
When R ¹ , R ² , R ³ and R ⁴ are each an alkynyl group, it is preferably 2 to 20 carbon atoms, more preferably 2 to 8 carbon atoms, and 2 to 4 carbon atoms. It is particularly preferred that

When R ¹ , R ² , R ³ and R ⁴ are each an aryl group, it is preferably 6 to 24 carbon atoms, more preferably 6 to 18 carbon atoms, and 6 to 10 carbon atoms. Is particularly preferable from the viewpoint of reducing the humidity dependence. Specifically, a benzene ring and a naphthalene ring are preferable, and a benzene ring is particularly preferable.
When R ¹ , R ² , R ³ and R ⁴ are each a heterocyclic group, it is preferably 4 to 20 carbon atoms, more preferably 4 to 10 carbon atoms, and 4 to 4 carbon atoms. 6 is particularly preferable from the viewpoint of improving humidity dependency. Specific examples include a pyrrolyl group, a pyrrolidino group, a pyrazolyl group, a pyrazolidino group, an imidazolyl group, a piperazino group, and a morpholino group.

In the general formulas (1) and (2), R ¹ , R ² , R ³ and R ⁴ are each preferably a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group.

Each of R ¹ , R ² , R ^3, and R ⁴ may or may not have one or more substituents if possible. Examples of the substituent that each of R ¹ , R ² , R ^3, and R ⁴ may have include the aforementioned substituent group T.

In general formulas (1) and (2), R ¹ , R ² , R ³ and R ⁴ are each a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted group. Heterocyclic groups are preferred.
One of R ¹ and R ² and one of R ³ and R ⁴ are each preferably a hydrogen atom or a substituted or unsubstituted alkyl group, and particularly preferably a hydrogen atom. From the viewpoint of reducing the humidity dependence, the other is preferably a substituted or unsubstituted aryl group.

In the general formulas (1) and (2), X ² and X ⁴ each represent a single bond or a divalent linking group; X ¹ and X ³ each represent a single bond or the following divalent linking group group (5 Represents a group selected from
Examples of the divalent linking group represented by each of X ² and X ⁴ include an alkylene group (preferably having 1 to 30 carbon atoms, more preferably 1 to 3 carbon atoms, and particularly preferably 2 carbon atoms), arylene A group (preferably having 6 to 30 carbon atoms, more preferably 6 to 10 carbon atoms) or the following divalent linking group group (5) is included.

In each formula, the * side is a linking site with the N atom substituted on the pyrimidine ring or pyridine ring in the compound represented by each formula; R ^g is an alkyl group, an alkenyl group, an alkynyl group, an aryl group, Or represents a heterocyclic group. The preferred range of the number of carbon atoms in each group is the same as the preferred range of the number of carbon atoms in the group represented by ^Xa and ^Xb .

X ² and X ⁴ each preferably represents a single bond or any group selected from a divalent linking group group (5), and X ² is a single bond and X ¹ is a divalent linking group group ( 5) represents any group selected from 5); and X ⁴ is a single bond and X ³ preferably represents any group selected from the divalent linking group group (5).
In that case, each of X ¹ and X ³ is more preferably any one of —CO—, —COO—, and —CO (NRg) —, and particularly preferably —CO—.
For example, when X ¹ is a predetermined divalent linking group (particularly preferably —CO—) and X ² is a single bond, R ¹ is a substituted or unsubstituted alkyl group, substituted or unsubstituted aryl Or a substituted or unsubstituted heterocyclic group (preferably a substituted or unsubstituted aryl group from the viewpoint of reducing humidity dependency), and R ² is preferably a hydrogen atom; When X ³ is a predetermined divalent linking group (preferably —CO—) and X ⁴ is a single bond, R ³ is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or It is particularly preferably a substituted or unsubstituted heterocyclic group (preferably a substituted or unsubstituted aryl group from the viewpoint of reducing humidity dependency), and R ⁴ is particularly preferably a hydrogen atom.

Furthermore, in the general formula (1), when X ¹ is a predetermined divalent linking group, R ¹ is preferably an aryl group, and more preferably a phenyl group. The aryl group may have one or more substituents selected from the above substituent group T. The substitution position of the substituent is not particularly limited, and any position of the ortho, meta, and para positions may be substituted with respect to X ¹ . Examples of preferable substituents include a halogen atom, a hydroxyl group, a carbamoyl group, a sulfamoyl group, an alkyl group (preferably an alkyl group having 1 to 8 carbon atoms), an alkoxy group (preferably an alkoxy group having 1 to 8 carbon atoms). , An alkylamino group (preferably an alkylamino group having 1 to 8 carbon atoms) or a dialkylamino group (preferably a dialkylamino group having 1 to 8 carbon atoms), and an alkyl group (preferably having 1 carbon atom). ˜8 alkyl groups) and alkoxy groups (preferably alkoxy groups having 1 to 8 carbon atoms) are more preferred, and alkyl groups or alkoxy groups having 1 to 4 carbon atoms are more preferred.

In the general formula (2), when X ¹ and X ³ are each a divalent linking group, each of R ¹ and R ³ is preferably an aryl group, and more preferably a phenyl group. The aryl group may have one or more substituents selected from the above substituent group T. There are no particular restrictions on the substitution position of the substituent, and any of the ortho, meta, and para positions may be substituted for X ¹ and X ^3, respectively. Examples of preferable substituents include a halogen atom, a hydroxyl group, a carbamoyl group, a sulfamoyl group, an alkyl group (preferably an alkyl group having 1 to 8 carbon atoms), an alkoxy group (preferably an alkoxy group having 1 to 8 carbon atoms). , An alkylamino group (preferably an alkylamino group having 1 to 8 carbon atoms) or a dialkylamino group (preferably a dialkylamino group having 1 to 8 carbon atoms), and an alkyl group (preferably having 1 carbon atom). ˜8 alkyl groups) and alkoxy groups (preferably alkoxy groups having 1 to 8 carbon atoms) are more preferred, and alkyl groups or alkoxy groups having 1 to 4 carbon atoms are more preferred.

On the other hand, each of X ¹ , X ² , X ³ and X ^{4 in} the general formulas (1) and (2) is a divalent group represented by the divalent linking group group represented by the general formula (5). When it is not any of the linking groups, X ¹ , X ² , X ³ and X ⁴ are each preferably a single bond, and R ¹ , R ² , R ³ and R ⁴ bonded to each are hydrogen atoms. Preferably there is.

  Examples of the compound represented by the general formula (1) include a compound represented by the following general formula (3).

Each symbol in the general formula (3) has the same meaning as that in the general formula (1), and preferred ranges and specific examples are also the same. Examples of the compound represented by the general formula (3) include a compound in which —Q ^a —R ^a is a group other than —OH and —SH.

  Examples of the compound represented by the general formula (1) include a compound represented by the following general formula (4).

  The definition of each symbol in General formula (4) is synonymous with each in General formula (1), and its preferable range and specific example are also the same.

  Preferable examples of the compound represented by the general formula (1) include a compound represented by the following general formula (6).

The definition of each symbol in General formula (6) is synonymous with each in General formula (2); Ar < ¹ > and Ar < ² > respectively represent an aryl group.
The aryl group represented by each of Ar ¹ and Ar ² is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group represented by each of Ar ¹ and Ar ² may have one or more substituents, and examples of the substituent include the substituent group T. Preferred examples of the substituent are the same as the preferred examples of the substituent which R ¹ and R ³ in the general formula (2) have. Ar ¹ and Ar ² may of course be the same or different from each other. For example, one may be an unsubstituted aryl group and the other may be the same aryl group, and may be a substituted aryl group having one or more substituents. Both may be the same aryl group as each other, provided that they are different substituted aryl groups substituted with different substituents.

In an example of the synthesis method of the general formula (6), if a reagent for introducing different Ar ¹ and Ar ² is used to produce a compound having different Ar ¹ and Ar ² , Ar ¹ is introduced. , A compound having Ar ² introduced therein, and one or two compounds each having different Ar ¹ and Ar ² from each other (when Y is a nitrogen atom, they are identified as two compounds) In some cases, a mixture of three or four of the following may be obtained. In this invention, you may use the said mixture as an additive of a polymer film as it is. That is, a mixture of compounds represented by the following general formulas (6a) to (6d) (where Y is a methine group (6a) to (6c)) may be used as an additive.

The definition of each symbol in general formula (6a)-(6d) is synonymous with each in general formula (2), However, Ar < ¹ > and Ar < ² > represent a mutually different group, respectively.

Q ^a is a single bond or ^a divalent linking group represented by —O—, —S—, —N (X ^a —R ^h ) —, or —N (X ^a —R ^h ) —X ^b —. Is preferred. Among them, it is a single bond, or —O—, —S—, —NH— or —N (R) — (wherein R is an alkyl group having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms). Is more preferable, and a single bond or —O— is still more preferable. R ^a is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkynyl group having 2 to 8 carbon atoms, or an aryl group having 6 to 18 carbon atoms (for example, benzene A ring and a naphthalene ring group), a heterocyclic group having 4 to 10 carbon atoms (for example, pyrrolyl group, pyrrolidino group, pyrazolyl group, pyrazolidino group, imidazolyl group, piperazino group, morpholino group) are preferable; and a hydrogen atom Or an alkyl group having 1 to 8 carbon atoms, and more preferably an alkyl group having 1 to 4 carbon atoms. The alkyl group may have a substituent, but is preferably unsubstituted. Examples of the substituent include a hydroxy group, a cyano group, an alkoxy group, an alkoxycarbonyl group, and an amino group. R ^a may be bonded to R to form a ring (for example, a 5- or 6-membered ring) when Q ^a is —N (R) —. Examples of the compound represented by the general formula (6) include a compound in which —Q ^a —R ^a is a group other than —OH and —SH.

  In the general formula (6) and the compounds of the general formulas (7) to (10) described later, the Rth of the polymer film in which the Rth is controlled by adding these compounds varies depending on the humidity. There is a feature that is reduced more.

  Preferable examples of the compound represented by the general formula (1) include a compound represented by the following general formula (7).

The definition of each symbol in the general formula (7), be a general formula (2), respectively the same meaning as in; R ^a7 represents an alkyl group having 1 to 8 carbon ^{atoms; R 11, R 12, R} 13 , R ¹⁴ , R ¹⁵ and R ¹⁶ each represent a hydrogen atom, a halogen atom, a carbamoyl group, a sulfamoyl group, an alkyl group having 1 to 8 carbon atoms, or an alkoxy group having 1 to 8 carbon atoms. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are each preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkoxy group having 1 to 8 carbon atoms. Particularly preferred is an atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. R ^{11 to} R ¹⁶ may of course be the same or different. For example, all of R ^{11 to} R ¹³ or R ^{14 to} R ¹⁶ may be hydrogen atoms, and at least one of R ^{14 to} R ¹⁶ or at least one of R ^{11 to} R ¹³ may be the substituent. teeth; and at least one of R11 to R13, and at least one of R ¹⁴ to R ¹⁶ may be different from each other said substituent.

  Examples of the compound represented by the general formula (7) include compounds represented by the following general formulas (8) to (10).

The definition of each symbol in Formula (8)-(10) is synonymous with each in General formula (7); R ^<a8> , R ^<a9> and R ^<a10> are respectively C1-C8 (preferably carbon Represents an alkyl group having 1 to 4 atoms.

  Further, the compound represented by the following formula (11) (preferably the following general formula (11a)) is more effective in increasing Re and Rth than the compounds represented by the above general formulas (6) to (10). However, it is preferably used in applications that require relatively low Re and Rth.

The definition of each symbol in a formula is synonymous with each in General formula (1), and its preferable range and a preferable example are also the same. Examples of the general formula (11) and the compound represented by (11a), -Q ^a -R ^a is includes compounds is a group other than -OH and -SH.

In addition, the compound represented by the following formula (12) also exhibits a high retardation increasing action like the compounds of the general formulas (6) to (10).

The definition of each group in a formula is synonymous with each in said general formula (1)-(10), and its preferable range is also the same. Q ¹² is a single bond, —NH—, —O—, or —S—, and R ¹² is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group having 6 to 18 carbon atoms (for example, Benzene ring and naphthalene ring group), or a heterocyclic group having 4 to 10 carbon atoms (for example, pyrrolyl group, pyrrolidino group, pyrazolyl group, pyrazolidino group, imidazolyl group, piperazino group, morpholino group), preferably , A hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group having 6 to 18 carbon atoms. When Q ¹² is a single bond, —O—, or —S—, R ¹² is particularly preferably a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and Q 12 is —NH—. In particular, R ¹² is preferably an aryl group having 6 to 18 carbon atoms (more preferably a benzene ring group). Examples of the compound represented by the general formula (12) include a compound in which —Q ^a —R ^a is a group other than —OH and —SH.

  Specific examples of the compound represented by the general formula (1) are shown below, but the compounds that can be used in the present invention are not limited to the following specific examples.

  The compound represented by the general formula (1) used in the present invention preferably has a molecular weight of 200 to 2000, more preferably 200 to 1000, and particularly preferably 200 to 600.

The method for producing the compound represented by the general formula (1) is not particularly limited and can be produced by various methods.
The compound of General formula (1) is compoundable by the method of the following scheme 1-1, for example. That is, it can be synthesized by reacting the compound of the general formula (1a) and the compound of the general formula (1b) in an organic solvent in the presence of a base. The definition of each group in General formula (1a) and General formula (1b) is synonymous with each in General formula (1). Z represents a leaving group, and a halogen atom, an alkoxy group, an aryloxy group, a heterocyclic group, an alkylsulfonyloxy group, an arylsulfonyloxy group, or the like can be preferably used.

  As the compounds of the general formula (1a) and the general formula (1b), commercially available products or synthetic products produced by a known synthesis method can be used. Examples of the organic solvent include alcohol (eg, methanol, ethanol), ester (eg, ethyl acetate), hydrocarbon (eg, toluene), ether (eg, tetrahydrofuran), amide (eg, dimethylformamide, dimethylacetamide, N-methyl). (Pyrrolidone, N-ethylpyrrolidone), halogenated hydrocarbon (eg, dichloromethane), nitrile (eg, acetonitrile) or a mixed solvent thereof can be used. Alcohols and amides are preferred, and methanol, ethanol, N-methylpyrrolidone and N-ethylpyrrolidone are particularly preferred. A mixed solvent of methanol, ethanol, N-methylpyrrolidone and N-ethylpyrrolidone is also a particularly suitable example.

  As the base, any of an inorganic base (eg, potassium carbonate) and an organic base (eg, triethylamine, sodium methoxide, sodium ethoxide) can be used, and can be appropriately selected according to the kind of Z. When Z is an alkoxy group, an inorganic base is preferable, and sodium methoxide is particularly preferable. The amount of the base used is preferably in the range of 0.5 to 10 equivalents, particularly preferably in the range of 1 to 3 equivalents, relative to the compound represented by the general formula (1b).

The reaction temperature is usually preferably in the range of −20 ° C. to the boiling point of the solvent used, and preferably in the range of room temperature to the boiling point of the solvent.
The reaction time is usually 10 minutes to 3 days, preferably 1 hour to 1 day. The reaction may be performed under a nitrogen atmosphere or under reduced pressure. In particular, when the leaving group Z is an alkoxy group or an aryloxy group, the reaction is preferably performed under reduced pressure.

Another example of the method for producing the compound represented by the general formula (1) is a method represented by the following scheme 1-2. That is, it can be synthesized by reacting the compound of the general formula (1c) and the compound of the general formula (1d) in an organic solvent in the absence of a base or in the presence of a base.
As the compounds of general formula (1c) and general formula (1d), commercially available products or synthetic products produced by known synthesis methods can be used. Examples of the organic solvent include alcohol (eg, methanol, ethanol), ester (eg, ethyl acetate), hydrocarbon (eg, toluene), ether (eg, tetrahydrofuran), amide (eg, dimethylformamide, dimethylacetamide, N-methyl). (Pyrrolidone, N-ethylpyrrolidone), halogenated hydrocarbon (eg, dichloromethane), nitrile (eg, acetonitrile) or a mixed solvent thereof can be used. Alcohols and amides are preferred, and methanol, ethanol, N-methylpyrrolidone and N-ethylpyrrolidone are particularly preferred. A mixed solvent of methanol, ethanol, N-methylpyrrolidone and N-ethylpyrrolidone is also a particularly suitable example.

  When a base is used, any of an inorganic base (eg, potassium carbonate) and an organic base (eg, triethylamine, sodium methoxide, sodium ethoxide) can be used as the base. Inorganic bases are preferred, with sodium hydroxide, sodium carbonate, and sodium bicarbonate being particularly preferred. The amount of the base used is preferably in the range of 0.5 to 10 equivalents, particularly preferably in the range of 1 to 3 equivalents, relative to the compound represented by the general formula (1c).

Usually, the reaction temperature is preferably in the range of −20 ° C. to the boiling point of the solvent used, more preferably in the range of room temperature to the boiling point of the solvent.
The reaction time is usually 10 minutes to 3 days, preferably 1 hour to 1 day. The reaction may be performed under a nitrogen atmosphere or under reduced pressure.

In general formula (1c) and general formula (1d), the definition of each group is synonymous with each in general formula (1). Z ¹ represents a leaving group, and a halogen atom or the like can be preferably used.
In general formula (1c) and general formula (1d), the definition of each group is synonymous with each in general formula (1). Z represents a leaving group.

  Moreover, the compound of General formula (2) 'which is an example of General formula (2) is compoundable by the method of the following scheme 2-1. That is, it can be synthesized by reacting the compound of the general formula (2a) and the compound of the general formula (2b) in an organic solvent in the presence of a base. As the compounds of general formula (2a) and general formula (2b), commercially available products or synthetic products produced by known synthesis methods can be used. Examples of the organic solvent and base that can be used are the same as those in the reactions of Schemes 1-1 and 1-2, and the reaction temperature and reaction time are also the same as those in the reaction of the above scheme.

  In general formula (2a), the definition of each group is synonymous with each in general formula (2). Moreover, it is the same as that of what was mentioned above about general formula (1b).

  Moreover, the compound of General formula (7) 'which is an example of General formula (7) is compoundable by the method of the following scheme 3-1. That is, it can be synthesized by reacting the compound of the general formula (7a) and the compound of the general formula (7b) in an organic solvent in the presence of a base. As the compounds of general formula (7a) and general formula (7b), commercially available products or synthetic products produced by known synthesis methods can be used. Examples of the organic solvent and base that can be used are the same as those in the reactions of Schemes 1-1 and 1-2, and the reaction temperature and reaction time are also the same as those in the reaction of the above scheme.

  In general formula (7a) and general formula (7b), the definition of each group is synonymous with each in general formula (7). Moreover, the definition of Z is synonymous with that in the general formula (1b).

(2) Compound represented by general formula (101) or (102) As a compound preferably used as a humidity dependency improver in the present invention, a compound represented by the following general formula (101) or (102) Is mentioned.

  Formula (101)

(In the general formula (101), R _A represents an alkyl group, an alkenyl group, an alkynyl group, a heterocyclic group or an aryl group. X ¹⁰¹ , X ¹⁰² , X ¹⁰³ and X ¹⁰⁴ are each independently a single bond or a divalent group. And R ¹⁰¹ , R ¹⁰² , R ¹⁰³ and R ¹⁰⁴ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an acyl group or a heterocyclic group.

  General formula (102)

(In the general formula (102), R _B and R _C each independently represents an alkyl group, an alkenyl group, an alkynyl group, a heterocyclic group or an aryl group. X ¹⁰⁵ and X ¹⁰⁶ each independently represent a single bond or a divalent group. R ⁵ and R ⁶ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an acyl group or a heterocyclic group.
X ^{101 to} X ¹⁰⁶ each represents a single bond or a divalent linking group, and may be the same or different, and the divalent linking group is represented by the following general formula (103). It is preferable to be selected from the group.

  General formula (103)

  Hereinafter, compounds represented by the general formula (101) or (102) that can be preferably used in the present invention are shown as the humidity dependency improving agent. However, the present invention is not limited to the following specific examples.

(3) Compound containing hydroxyl group A compound containing a hydroxyl group that is preferably used as the humidity-dependent improving agent in the present invention, and more preferably a compound containing a phenolic hydroxyl group is disclosed in, for example, JP-A-2008-89860. The compound A described on pages 13 to 19 of the above and the compound represented by the general formula (I) described on pages 7 to 9 of JP-A-2008-233530 can be preferably used.

(Other resins contained in the outer layer)
In the present invention, an acrylic resin can be added to the outer layer. The ratio of the acrylic resin to the cellulose acylate is preferably 2 to 140% by mass, more preferably 4 to 100% by mass, and most preferably 6 to 60% by mass, based on the cellulose acylate. Moreover, 1000-200,000 are preferable, as for the molecular weight of an acrylic resin, More preferably, it is 1000-100,000, Most preferably, it is 1500-50,000 or less, Most preferably, it is 1500-10,000. By making it into this molecular weight range, the transparency of the cellulose acylate layer is excellent.

<Additives>
In the optical film of the present invention, in each of the core layer and the outer layer, an additive other than the humidity dependence improver is added together with one or more thermoplastic resins as main raw materials. You may make it contain as long as it is not contrary to.
Hereinafter, additives that may be added to the optical film of the present invention will be described.

(Plasticizer)
In the present invention, a plasticizer may be used to give flexibility to the optical film, improve dimensional stability, and improve moisture resistance.

  Examples of the plasticizer that is preferably added include low-molecular to oligomeric compounds having a molecular weight of about 190 to 5,000 within the above physical properties. For example, phosphoric acid esters, carboxylic acid esters, polyol esters, and the like are used.

  Examples of phosphate esters include triphenyl phosphate (TPP), tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, biphenyl diphenyl phosphate, trioctyl phosphate, tributyl phosphate, and the like. Triphenyl phosphate and biphenyl diphenyl phosphate are preferable.

Representative examples of the carboxylic acid ester include phthalic acid esters and citric acid esters. Examples of the phthalic acid ester include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, diphenyl phthalate, diethyl hexyl phthalate and the like. Examples of the citrate ester include O-acetyl triethyl citrate, O-acetyl tributyl citrate, acetyl triethyl citrate, and acetyl tributyl citrate.
These preferred plasticizers are liquid except for TPP (melting point: about 50 ° C.) at 25 ° C., and the boiling point is 250 ° C. or higher.

  Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters. Examples of glycolic acid esters include triacetin, tributyrin, butyl phthalyl butyl glycolate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, methyl phthalyl methyl glycolate, propyl phthalyl Examples include propyl glycolate, butyl phthalyl butyl glycolate, and octyl phthalyl octyl glycolate.

  JP-A-5-194788, JP-A-60-250053, JP-A-4-227941, JP-A-6-16869, JP-A-5-271471, JP-A-7-286068, JP-A-5-5047. No. 11, JP-A-11-80381, JP-A-7-20317, JP-A-8-57879, JP-A-10-152568, JP-A-10-120824, etc. are also preferably used. It is done. According to these publications, there are many preferable descriptions regarding not only examples of plasticizers but also their usage or characteristics, and they are preferably used in the present invention.

  Other plasticizers include (di) pentaerythritol esters described in JP-A No. 11-124445, glycerol esters described in JP-A No. 11-246704, diglycerol esters described in JP-A No. 2000-63560, Citric acid esters described in JP-A No. 11-92574, substituted phenyl phosphate esters described in JP-A No. 11-90946, ester compounds containing an aromatic ring and a cyclohexane ring described in JP-A No. 2003-165868 are preferably used. .

A polymer plasticizer having a resin component having a molecular weight of 1,000 to 100,000 is also preferably used. For example, polyesters and / or polyethers described in JP-A No. 2002-22956, polyester ethers, polyester urethanes or polyesters described in JP-A No. 5-97073, copolyester ethers described in JP-A No. 2-292342, Examples thereof include an epoxy resin or a novolac resin described in JP-A No. 2002-146044.
Moreover, as a plasticizer which is excellent in terms of volatility resistance, bleed out, low haze, and the like, it is preferable to use, for example, a polyester diol described in JP 2009-98674 A, in which both ends are hydroxyl groups. Moreover, as a plasticizer which is excellent in terms of flatness and low haze of the optical film, a sugar ester derivative described in WO2009 / 031464 is also preferable.

  These plasticizers may be used alone or in combination of two or more. The addition amount of the plasticizer can be used in an amount of 2 to 120 parts by weight with respect to 100 parts by weight of the thermoplastic resin, preferably 2 to 70 parts by weight, more preferably 2 to 30 parts by weight, particularly 5 to 20 parts by weight. preferable. In addition, when a common plasticizer is used for adjacent layers of the outer layer dope (A) and the core layer dope (B) used in the manufacturing method of the present invention described later, the occurrence of disturbance of the dope interface during casting is reduced. From the viewpoint of improving the adhesion of the interface or reducing the curl. In particular, the outer layer dope (A) and the core layer dope (B) preferably contain a common plasticizer.

(UV absorber)
An ultraviolet absorber may be further added to the optical film of the present invention in order to improve the light resistance of the film itself or to prevent deterioration of an image display member such as a polarizing plate or a liquid crystal compound of a liquid crystal display device.

  As the ultraviolet absorber, one having an excellent ability to absorb ultraviolet rays having a wavelength of 370 nm or less from the viewpoint of preventing deterioration of the liquid crystal and having as little absorption of visible light having a wavelength of 400 nm or more as possible from the viewpoint of good image display properties is used. It is preferable. In particular, the transmittance at a wavelength of 370 nm is desirably 20% or less, preferably 10% or less, and more preferably 5% or less. Examples of such ultraviolet absorbers include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and ultraviolet absorbing groups as described above. Examples thereof include, but are not limited to, polymer ultraviolet absorbing compounds. Two or more kinds of ultraviolet absorbers may be used.

  The optical film of the present invention may contain an additive together with one or more thermoplastic resins as main raw materials. Examples of the additive include a fluorine-based surfactant (preferably added in an amount of 0.001 to 1% by mass with respect to the thermoplastic resin), a release agent (0.0001 to 1% by mass), a deterioration inhibitor (0. 0001 to 1% by mass), an optical anisotropy control agent (0.01 to 10% by mass), an infrared absorber (0.001 to 1% by mass), and the like.

Moreover, the particle | grains which consist of a trace amount organic material, an inorganic material, and mixtures thereof may be dispersedly included in the range which does not impair the effect of this invention. When these particles are added for the purpose of improving the transportability of the film during film formation (as a matting agent), the particle size of the particles is preferably 5 to 3000 nm, and the addition amount is 1% by mass or less. Is preferred.
Particles can also be added to give irregularities on the surface of the film or to impart light scattering properties to the inside of the film. In that case, the particle diameter of the particles is preferably 1 to 20 μm, and the added amount Is preferably 2 to 30% by mass. The difference between the refractive index of these particles and the refractive index of the polymer film of the present invention is preferably 0 to 0.5. Examples of inorganic material particles include particles of silicon oxide, aluminum oxide, barium sulfate, etc. Is included. Examples of organic material particles include acrylic resin, divinylbenzene resin, benzoguanamine resin, styrene resin, melamine resin, acrylic-styrene resin, polycarbonate resin, polyethylene resin, polyvinyl chloride resin, etc. included.

<Lamination of additional layers on optical film>
In the optical film of the present invention, for example, a curable resin layer having a thickness of 0.1 μm or more and 15 μm or less may be further provided thereon. In the optical film of the present invention, an optical functional layer such as an antistatic layer, a high refractive index layer, or a low refractive index layer can be provided on the curable resin layer. The curable resin layer can also serve as an antistatic layer or a high refractive index layer.
The curable resin layer is preferably formed by a crosslinking reaction or a polymerization reaction of an ionizing radiation curable compound. For example, it is formed by applying a coating composition containing an ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer on a light-transmitting substrate and causing the polyfunctional monomer or polyfunctional oligomer to undergo a crosslinking reaction or a polymerization reaction. be able to.
The functional group of the ionizing radiation curable polyfunctional monomer or polyfunctional oligomer is preferably a light, electron beam, or radiation polymerizable group, and among them, a photopolymerizable functional group is preferable.
Examples of the photopolymerizable functional group include unsaturated polymerizable functional groups such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group. Among them, a (meth) acryloyl group is preferable.
In addition, additives such as a known leveling agent, antifouling agent, antistatic agent, refractive index adjusting inorganic filler, scattering particles, and thixotropic agent can be used for the curable resin layer.

  The strength of the optical film provided with the curable resin layer is preferably H or higher, more preferably 2H or higher, in a pencil hardness test.

<Film characteristics>
(Photoelastic coefficient)
The photoelastic coefficient is an intrinsic property of a substance, and a substance that hardly expresses the photoelastic coefficient is rather rare. For example, many polymer resins exhibit birefringence due to external stress or thermal stress. The photoelastic coefficient can define a sign in relation to the direction of applied stress. That is, when tensile stress is applied to the medium (polymer resin), the refractive index n _para for the polarized light having the polarization plane in the direction parallel to the tensile stress and the refractive index for the polarized light having the polarization plane in the direction orthogonal thereto. Thus, the sign of the photoelastic coefficient is expressed by the sign of the photoelastic coefficient c expressed by the following equation (1B).
c = Δn / σ = (n _para −n _perp ) / σ (1B)
That is, the photoelastic coefficient is positive when n _para is larger than n _perp and negative when it is smaller.

When the optical film of the present invention is used as a polarizing plate protective film, birefringence (Re, Rth) may change due to stress caused by the contraction of the polarizer. Such a change in birefringence due to the stress can be measured as a photoelastic coefficient, but the range is preferably -3 × 10 ⁻¹² Pa ^{−1 to} 3 × 10 ⁻¹² Pa ⁻¹ , and −1 ×. More preferably, it is 10 ⁻¹² Pa ⁻¹ to 1 × 10 ⁻¹² Pa ⁻¹ .
By controlling the photoelastic coefficient within the above range, a circular color change when the panel incorporating the polarizing plate using the film of the present invention is subjected to a wet heat durability test and observed from the licking direction of the liquid crystal display device Generation can be suppressed.

(Retardation)
In this specification, Re (λ) and Rth (λ) respectively represent in-plane retardation and retardation in the thickness direction at a wavelength λ. In the present specification, the wavelength λ is 590 nm unless otherwise specified. Re (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments). In selecting the measurement wavelength λnm, the wavelength selection filter can be exchanged manually, or the measurement value can be converted by a program or the like.

In this specification, Re and Rth (unit: nm) are determined according to the following method. First, the film was conditioned at 25 ° C. and 60% relative humidity for 24 hours, and then a prism coupler (MODEL2010 Prism Coupler: manufactured by Metricon) was used. At 25 ° C. and 60% relative humidity, the following formula was used: The average refractive index (n) represented by (10) is obtained.
Formula (10): n = (nTE × 2 + nTM) / 3
[Where nTE is a refractive index measured with polarized light in the film plane direction, and nTM is a refractive index measured with polarized light in the film surface normal direction. ]

When the film to be measured is represented by a uniaxial or biaxial refractive index ellipsoid, Rth (λ) is calculated by the following method.
Rth (λ) is Re (λ), with the in-plane slow axis (determined by KOBRA 21ADH or WR) as the tilt axis (rotation axis) (in the absence of the slow axis, any in-plane value) The light is incident at a wavelength of λ nm from the inclined direction in steps of 10 degrees from the normal direction to 50 degrees on one side with respect to the film normal direction of the rotation axis of KOBRA 21ADH or WR is calculated based on the measured retardation value, the assumed value of the average refractive index, and the input film thickness value.
In the above case, in the case of a film having a direction in which the retardation value is zero at a certain tilt angle with the in-plane slow axis from the normal direction as the rotation axis, retardation at a tilt angle larger than the tilt angle. The value is calculated by KOBRA 21ADH or WR after changing its sign to negative.
In addition, the retardation value is measured from the two inclined directions, with the slow axis as the tilt axis (rotation axis) (in the absence of the slow axis, the arbitrary direction in the film plane is the rotation axis), Based on the value, the assumed value of the average refractive index, and the input film thickness value, Rth can also be calculated from the following equations (11) and (12).

上記のＲｅ(θ)は法線方向から角度θ傾斜した方向におけるレターデーション値を表す。
式（１１）におけるｎｘは面内における遅相軸方向の屈折率を表し、ｎｙは面内においてｎｘに直交する方向の屈折率を表し、ｎｚはｎｘ及びｎｙに直交する方向の屈折率を表す。ｄは膜厚である。
式（１２）
Ｒｔｈ＝｛（ｎｘ＋ｎｙ）／２−ｎｚ｝ｘｄ
測定されるフィルムが１軸や２軸の屈折率楕円体で表現できないもの、いわゆる光学軸（ｏｐｔｉｃ ａｘｉｓ）がないフィルムの場合には、以下の方法によりＲｔｈ（λ）は算出される。
Ｒｔｈ（λ）は前記Ｒｅ（λ）を、面内の遅相軸（ＫＯＢＲＡ ２１ＡＤＨまたはＷＲにより判断される）を傾斜軸（回転軸）としてフィルム法線方向に対して−５０度から＋５０度まで１０度ステップで各々その傾斜した方向から波長λｎｍの光を入射させて１１点測定し、その測定されたレターデーション値と平均屈折率の仮定値及び入力された膜厚値を基にＫＯＢＲＡ ２１ＡＤＨまたはＷＲが算出する。
上記の測定において、平均屈折率の仮定値は ポリマーハンドブック（ＪＯＨＮ ＷＩＬＥＹ＆ＳＯＮＳ，ＩＮＣ）、各種光学フィルムのカタログの値を使用することができる。平均屈折率の値が既知でないものについてはアッベ屈折計で測定することができる。主な光学フィルムの平均屈折率の値を以下に例示する：セルロースアシレート（１．４８）、シクロオレフィンポリマー（１．５２）、ポリカーボネート（１．５９）、ポリメチルメタクリレート（１．４９）、ポリスチレン（１．５９）である。これら平均屈折率の仮定値と膜厚を入力することで、ＫＯＢＲＡ ２１ＡＤＨまたはＷＲはｎｘ、ｎｙ、ｎｚを算出する。この算出されたｎｘ、ｎｙ、ｎｚよりＮｚ＝（ｎｘ−ｎｚ）／（ｎｘ−ｎｙ）が更に算出される。

The above Re (θ) represents a retardation value in a direction inclined by an angle θ from the normal direction.
In formula (11), nx represents the refractive index in the slow axis direction in the plane, ny represents the refractive index in the direction orthogonal to nx in the plane, and nz represents the refractive index in the direction orthogonal to nx and ny. . d is the film thickness.
Formula (12)
Rth = {(nx + ny) / 2−nz} xd
In the case where the film to be measured cannot be expressed by a uniaxial or biaxial refractive index ellipsoid, that is, a film having no so-called optical axis, Rth (λ) is calculated by the following method.
Rth (λ) is the above-mentioned Re (λ), and the in-plane slow axis (determined by KOBRA 21ADH or WR) is the tilt axis (rotation axis) from −50 degrees to +50 degrees with respect to the film normal direction. The light of wavelength λ nm is incident from each inclined direction in 10 degree steps and measured at 11 points. Based on the measured retardation value, the assumed average refractive index, and the input film thickness value, KOBRA 21ADH or WR is calculated.
In the above measurement, the assumed value of the average refractive index may be a value in a polymer handbook (John Wiley & Sons, Inc.) or a catalog of various optical films. 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 these assumed values of average refractive index and film thickness, KOBRA 21ADH or WR calculates nx, ny, and nz. Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny, and nz.

The optical film of the present invention preferably has −5 nm ≦ Re ≦ 5 nm, more preferably −3 nm ≦ Re ≦ 3 nm, and particularly preferably −2 nm ≦ Re ≦ 2 nm.
The optical film of the present invention preferably has −15 nm ≦ Rth ≦ 15 nm, more preferably 10 nm ≦ Rth ≦ −10 nm, and particularly preferably −7 nm ≦ Rth ≦ 7 nm.

(Rth humidity dependence)
In the present invention, the humidity dependence of Rth (ΔRth (10% -80%)) is calculated from the retardation value in the film thickness direction: Rth (H%) when the relative humidity is H (unit:%). The
As for the retardation value when the humidity of the optical film of the present invention is changed, ΔRth (10% -80%) defined by the following formula (II) is preferably −10 to 5 nm.
Formula (II) ΔRth (10% -80%) = Rth (10%)-Rth (80%)
(In the formula (II), Rth (10%) represents the value of retardation Rth in the film thickness direction at a film wavelength of 590 nm, 25 ° C. and 10% relative humidity. Rth (80%) represents the film wavelength of 590 nm. Represents the value of retardation Rth in the film thickness direction at 25 ° C. and 80% relative humidity.)
Rth (H%) is the same as the above method at 25 ° C. and relative humidity H% after conditioning the film for 24 hours at 25 ° C. and relative humidity H%, and the measurement wavelength at relative humidity H% is 590 nm. The retardation value at a certain time is measured and calculated. When Rth is simply written without specifying the relative humidity, it is a value measured at a relative humidity of 60%.
ΔRth (10% -80%) of the optical film of the present invention is more preferably −5 to 5 nm, and particularly preferably −3 to 3 nm.
By controlling the retardation value when the humidity is changed, the change in retardation when the external environment changes can be reduced, and a highly reliable liquid crystal display device can be provided.
Further, by reducing ΔRth of the optical film of the present invention, an effect of improving the circular color change visually recognized when the liquid crystal display device is observed obliquely on the display surface under specific conditions can be obtained. .

[Method for Producing Optical Film of the Present Invention]
The optical film manufacturing method of the present invention (hereinafter also referred to as the manufacturing method of the present invention) includes a cellulose acylate, a dope (A) containing a humidity dependency improving agent satisfying the following formula (I) and an organic solvent, and ( A dope (B) containing a (meth) acrylic resin and an organic solvent is simultaneously flown from the casting substrate side in the order of (A)-(B)-(A) onto the casting substrate by the co-casting method. Including a step of extending.
Formula (I) ΔRth (3) ≦ −4 nm
Formula (I ′) ΔRth (3) = (ΔRth (rh, 3) −ΔRth (rh, 0)
(In the formula (I), ΔRth (rh, 3) is a temperature of 25 ° C. of a 50 μm-thick film obtained by adding 3 parts by mass of a humidity dependency improver to 100 parts by mass of cellulose acetate having an acetyl substitution degree of 2.86. Represents a value obtained by subtracting Rth at 25 ° C. and 80% relative humidity from Rth at 10% humidity.ΔRth (rh, 0) is a cellulose having an acetyl substitution degree of 2.86 to which no humidity-dependent improving agent is added. This is a value obtained by subtracting Rth at 25 ° C. and relative humidity of 80% from Rth at 25 ° C. and relative humidity of 10% of a 50 μm-thick film of acetate, where Rth is the retardation in the film thickness direction of the film at a wavelength of 590 nm ( (Unit: nm)
Hereinafter, a preferable aspect is demonstrated about the manufacturing method of this invention.

(Film forming method)
Examples of the method for forming the optical film of the present invention include known film forming methods such as a solution casting method (solution casting method), a melt extrusion method, a calendar method, and a compression molding method. Among these, the production method of the present invention is characterized by producing the film of the present invention with high productivity by using a solution casting method (solution casting method).

<Preparation of dope>
Regarding the preparation of the thermoplastic resin solution (dope) used in the optical film of the present invention, the dissolution method is carried out by a room temperature dissolution method, a cooling dissolution method or a high temperature dissolution method, and further 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, JP JP-A-2000-273184, JP-A-11-323017, JP-A-11-302388, etc. describe methods for preparing cellulose acylate solutions. These techniques for dissolving cellulose acylate in an organic solvent can appropriately apply these techniques to the thermoplastic resin of the present invention. About these details, especially a non-chlorine type | system | group solvent system, it implements by the method described in detail on the 22-25th pages of the above-mentioned technical numbers 2001-1745. Further, the dope solution of the thermoplastic resin is usually subjected to solution concentration and filtration, and is also described in detail on page 25 of the above-mentioned technical number 2001-1745. 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 uses in a pressurized state.

(Organic solvent)
In the production method of the present invention, an organic solvent that dissolves the cellulose acylate and the (meth) acrylic resin to form a dope will be described. Examples of the organic solvent to be used include conventionally known organic solvents. For example, those having a solubility parameter in the range of 17 to 22 are preferable. Solubility parameters are described, for example, in J. Org. Brandrup, E.I. “Polymer Handbook (4th. Edition)” such as H and the like described in VII / 671 to VII / 714. Lower aliphatic hydrocarbon chloride, lower aliphatic alcohol, ketone having 3 to 12 carbon atoms, ester having 3 to 12 carbon atoms, ether having 3 to 12 carbon atoms, fat having 5 to 8 carbon atoms Group hydrocarbons, aromatic hydrocarbons having 6 to 12 carbon atoms, fluoroalcohols (for example, described in paragraph No. [0020] of JP-A-8-143709, paragraph No. [0037] of JP-A-11-60807) Compound) and the like.

  The solvent used in the present invention may be used alone or in combination, but it is preferable to use a mixture of a good solvent and a poor solvent in order to impart planar stability, more preferably a mixture of a good solvent and a poor solvent. The ratio of the good solvent is 60 to 99% by mass, and the poor solvent is 40 to 1% by mass. In the present invention, the good solvent means a resin that dissolves the resin used alone, and the poor solvent means a resin that swells or does not dissolve the resin used alone. Examples of the good solvent used in the present invention include organic halogen compounds such as methylene chloride and dioxolanes. Moreover, as a poor solvent used for this invention, methanol, ethanol, n-butanol, a cyclohexane etc. are used preferably, for example.

  Drying on the support (casting substrate) after film formation that the proportion of alcohol in the organic solvent contained in the dopes (A) and (B) is 10 to 50% by mass of the whole organic solvent. It is preferable for the reason that the time can be shortened and it can be quickly peeled off and dried, and more preferably 15 to 30% by mass.

(Dope solid content concentration)
The material forming the optical film is preferably dissolved in an organic solvent at a solid content concentration of 10 to 60% by mass (the sum of components that become solid after drying), more preferably 10 to 50% by mass. When the cellulose acylate resin is a main component, it is preferably dissolved by 10 to 30% by mass, preferably 15 to 25% by mass, and most preferably 18 to 20% by mass. However, depending on the use, there may be a case where the solid content concentration of the dope (A) is more than 20% by mass and less than 22% by mass because the content of the organic solvent can be reduced and the drying time can be shortened. is there. The method of preparing these solid content concentrations may be prepared so as to have a predetermined solid content concentration at the stage of dissolution, or prepared in advance as a low-concentration solution (for example, 9 to 14% by mass) in the concentration step. You may adjust to a predetermined high concentration solution. Furthermore, it is good also as a solution of the predetermined | prescribed low concentration by adding various additives later as a solution of the material which forms a high concentration light transmissive base material beforehand.
From the viewpoint of achieving support releasability, interfacial adhesion, and low curl, the composition of the thermoplastic resin in the dopes (A) and (B) preferably satisfies the following conditions. The proportion of the cellulose acylate resin in the thermoplastic resin in the dope (A) is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, and most preferably 80 to 100% by mass. The proportion of the acrylic resin in the thermoplastic resin in the dope (B) is preferably 30 to 100% by mass, more preferably 50 to 100% by mass, and most preferably 70 to 100% by mass.
On the other hand, in order to obtain a good planar film by co-casting, the difference in solid content between the dope (B) and the dope (A) is preferably within 10% by mass, and 5% by mass. Is more preferable.
In particular, in the dope (B), the solid content concentration is preferably 16 to 30% by mass, and the difference in the solid content concentration between the dope (B) and the dope (A) is preferably within 10% by mass.

(Complex viscosity of dope)
In the production method of the present invention, the complex viscosity η _A of the dope (A) flowing at 25 ° C. and the complex viscosity η _B of the dope (B) are controlled so as to satisfy the relationship of the following formula (III). It is preferable.
(Formula III) η _A ≦ η _B
In the production method of the present invention, among them, the complex viscosity of the dope (A) and the dope (B) is 10 to 80 Pa · s or less, and the complex viscosity of the dope (B) is the dope ( It is preferable that it is larger than the complex viscosity of A) from the viewpoint of improving the film surface shape after film formation.

In the production method of the present invention, it is preferable that the complex viscosity of the dope (A) and the dope (B) is 10 to 80 Pa · s or less. By setting the complex viscosity in such a range, the solution casting suitability tends to be further improved, which is preferable. Here, the complex viscosity of the dope in the present invention refers to a viscosity measured by solution shear rheometer measurement.
Within this range, the whitening suppression effect of the film is further enhanced. More preferably, it is 20-80 Pa * s, Most preferably, it is 25-70 Pa * s. The viscosity was measured as follows. 1 mL of the sample solution was measured with a rheometer (CLS 500) using Steel Cone (both manufactured by TA Instruments) with a diameter of 4 cm / 2 °.
Measurement was started after the sample solution was kept warm at the measurement start temperature until the liquid temperature became constant. Although the temperature at this time will not be specifically limited if it is the temperature at the time of the casting, Preferably it is -5-70 degreeC, More preferably, it is -5-35 degreeC. As described above, the value at 25 ° C. was adopted in the present invention.

<Co-casting process>
(Casting)
In the method for producing an optical film of the present invention, a dope (A) containing cellulose acylate and an organic solvent, and a dope (B) containing a (meth) acrylic resin and an organic solvent from the casting substrate side (A )-(B)-(A) in the order of casting on a casting base material simultaneously by a co-casting method.

  Furthermore, it is preferable to control the casting thickness of the dope (A) so that the dry thickness of the dope (A) is greater than 3 μm and 20 μm or less. There is no restriction | limiting in particular about the method of such casting thickness, A well-known method can be used. A more preferable dry thickness range is the same as the preferable thickness of the outer layer of the optical film of the present invention.

  The dope can be cast on a support and the solvent evaporated to form a film. Here, the support is not particularly limited, but is preferably a drum or a band. The surface of the support is preferably finished in a mirror state. For casting and drying methods in the solvent casting method, U.S. Pat. No. 736892, JP-B Nos. 45-4554, 49-5614, JP-A-60-176834, No. 60-203430, and No. 62-1115035.

FIG. 1 is a schematic view showing a main part of a casting facility having a band, and is a plan view from the side. The casting equipment 11 includes a casting die 14, first and second backup rollers 32 and 33, a band 31, a stripping roller 37, a temperature adjusting plate 51, a plurality of condensing plates 52, and a plurality of condensing plates 52. It consists of a liquid receiver 53, a recovery tank 56, and a liquid feed pipe. Note that three types of dopes can be prepared as the casting dope 12, and the casting film can be formed into a three-layer structure by a single casting operation. PS represents a casting start position. 36 represents a film.
FIG. 2 is a view showing a casting facility including a drum. FIG. 2 is a schematic view showing the main part of the casting equipment 101, and is a plan view from the side. In addition, about the apparatus and member similar to the above-mentioned FIG. 1, the same code | symbol is attached | subjected and description is abbreviate | omitted. In FIG. 2, a drum 102 is used instead of the band shown in FIG. The casting dope 12 from the casting die 14 is cast slightly below the uppermost part of the drum 102 so that the casting film formed on the drum 102 is directed downward from the casting start position PS. Also in this case, it is preferable to determine the casting start position PS so that the tangent line at the casting start position PS on the drum 102 matches the tangent line of the casting curve from the casting die 14 as much as possible.

  The drum 102 has a temperature adjustment function. A plurality of condensing plates 105 are installed outside the casting film. The condensing plates 105 enter the external liquid receiver 53 through the inclination of the gap between the condensing plates 105 and are collected in the collecting tank 56. The cast film traveling on the drum 102 is peeled off as a film 36 by a peeling roller 37 and sent to a drying facility which is the next process. Thereby, while preventing dripping, the cast film can be dried uniformly and the solvent can be recovered in a high yield. However, even when the rotation direction of the drum 102 is reversed and the running direction of the casting film is upward from the casting start position PS, the effect of uniform drying of the casting film and the uniformization of the thickness of the film 36 are obtained. It is done.

The dope is preferably cast on a support having a surface temperature of 5 ° C. or less. The surface temperature of the cast substrate (support) is preferably -30 to 5 ° C, more preferably -10 to 2 ° C.
After casting, it is preferable to dry it by applying air for 2 seconds or more. The obtained film can be peeled off from the support and further dried with high-temperature air whose temperature is successively changed from 100 ° C. to 160 ° C. to evaporate the residual solvent. The above method is described in Japanese Patent Publication No. 5-17844. According to this method, it is possible to shorten the time from casting to stripping. In order to carry out this method, it is necessary for the dope to gel at the surface temperature of the support during casting.

  In the present invention, the two or more kinds of dopes are cast on a support as a casting base material to form a film. There is no restriction | limiting in particular as a manufacturing method of the film of this invention other than the above, A well-known co-casting method can be used. For example, a film may be produced while casting and laminating a dope solution from a plurality of casting openings provided at intervals in the traveling direction of the metal support. For example, Japanese Patent Application Laid-Open No. 61-158414, The methods described in Japanese Laid-Open Patent Publication Nos. 1-122419 and 11-198285 can be applied. Further, the dope solution may be cast from two casting ports or formed into a film. For example, Japanese Patent Publication Nos. 60-27562, 61-94724, 61-947245, 61-947245, It can be carried out by the methods described in JP-A-61-104813, JP-A-61-158413, and JP-A-6-134933.

  In the production method of the present invention, the dope (A), (B), and (A) are simultaneously co-cast in order from the casting substrate side from the viewpoint of interfacial adhesion of the laminate and curl reduction. Here, a plurality of (A) in one laminated film may have the same composition or different compositions.

<Drying process>
The production method of the present invention includes a step of removing the organic solvent.
A method for drying a web which has been dried on a drum or band and peeled will be described. The web peeled at the peeling position immediately before the drum or belt makes one round is conveyed by alternately passing through a group of rolls arranged in a staggered manner, or both ends of the peeled web are gripped by clips or the like. It is transported by a non-contact transport method. Drying is performed by a method of applying wind at a predetermined temperature to both sides of the web (film) being conveyed or a method using a heating means such as a microwave. Since rapid drying may impair the flatness of the film to be formed, it is preferable to dry at a temperature at which the solvent does not foam in the initial stage of drying, and to dry at a high temperature after the drying proceeds. In the drying process after peeling from the support, the film tends to shrink in the longitudinal direction or the width direction by evaporation of the solvent. Shrinkage increases with drying at higher temperatures. Drying while suppressing this shrinkage as much as possible is preferable for improving the flatness of the finished film. From this point, for example, as shown in Japanese Patent Laid-Open No. 62-46625, a method in which all or part of the drying process is performed while holding the width at both ends of the web with clips or pins in the width direction. (Tenter method) is preferable. It is preferable that the drying temperature in the said drying process is 100-145 degreeC. The drying temperature, the amount of drying air, and the drying time vary depending on the solvent to be used.
In the present invention, it is preferable to dry the multilayer cast dope and then peel it from the support.

  In the present invention, the time for the dope to be cast and peeled on the casting substrate, that is, the time for transporting the dope on the casting substrate is preferably within 60 seconds, more preferably within 30 seconds. preferable.

<Extension process>
The manufacturing method of this invention may include the process of extending | stretching the said laminated | multilayer film formed into a film after the said film forming process.
In the production of the film of the present invention, the web (film) peeled from the support is preferably stretched when the amount of residual solvent in the web is less than 120% by mass.

The residual solvent amount can be expressed by the following formula.
Residual solvent amount (% by mass) = {(MN) / N} × 100
Here, M is the mass of the web at an arbitrary point in time, and N is the mass when the web of which M is measured is dried at 110 ° C. for 3 hours. If the amount of residual solvent in the web is too large, the effect of stretching cannot be obtained, and if it is too small, stretching becomes extremely difficult and the web may break. The more preferable range of the residual solvent amount in the web is most preferably 10% by mass to 50% by mass, particularly 12% by mass to 35% by mass. Further, if the stretching ratio is too small, a sufficient phase difference cannot be obtained, and if it is too large, stretching may become difficult and breakage may occur.

The draw ratio can be generally 5% to 100%, and is preferably 15% to 40%. Here, extending from 5% to 100% in one direction means that the distance between clips and pins supporting the film is in the range of 1.05 to 2.00 times the distance before stretching. Means.
Stretching may be performed in the film transport direction (longitudinal direction), in the direction orthogonal to the film transport direction (transverse direction), or in both directions.

In the present invention, the solution cast film can be stretched without being heated to a high temperature as long as the residual solvent amount is in a specific range, but it is preferable because drying and stretching can shorten the process. . In this invention, it is preferable that the extending | stretching temperature in the said extending process is 110-190 degreeC, and it is more preferable that it is 120-150 degreeC. The stretching temperature is preferably 120 ° C. or higher from the viewpoint of lowering haze, and 150 ° C. or lower is preferable from the viewpoint of enhancing optical expression (thin film forming).
On the other hand, since the plasticizer volatilizes when the temperature of the web is too high, the range of room temperature (15 ° C.) to 145 ° C. or lower is preferable when using a low molecular plasticizer that easily volatilizes as a plasticizer.

  In addition, stretching in biaxial directions perpendicular to each other is an effective method from the viewpoint of improving the optical expression of the film, particularly from the viewpoint of increasing the Rth (retardation) value of the film.

In this invention, you may extend | stretch to a biaxial direction simultaneously in a extending | stretching process, and may extend | stretch to a biaxial direction sequentially. When extending | stretching to a biaxial direction sequentially, you may change extending | stretching temperature for every extending | stretching in each direction.
In the case of simultaneous biaxial stretching, the film of the present invention can be obtained even when the stretching temperature is 110 ° C. to 190 ° C., and the stretching temperature in the case of simultaneous biaxial stretching is 120 ° C. to 150 ° C. More preferably, it is 130 to 150 degreeC. Further, by simultaneous biaxial stretching, the haze is increased to some extent, but the optical expression can be further enhanced.
On the other hand, when sequentially biaxially stretching, it is preferable to first stretch in a direction parallel to the film transport direction and then stretch in a direction orthogonal to the film transport direction. A more preferable range of the stretching temperature at which the successive stretching is performed is the same as the stretching temperature range at which the simultaneous biaxial stretching is performed.

<Heat treatment process>
The film production method of the present invention is preferably provided with a heat treatment step after the drying step. The heat treatment in the heat treatment step may be performed after completion of the drying step, and may be performed immediately after the stretching / drying step, or may be separately provided only after the winding process is performed by a method described later after the completion of the drying step. . In the present invention, it is preferable to provide the heat treatment step again after the drying step is once cooled to room temperature to 100 ° C. or less. This is because a film having better thermal dimensional stability can be obtained. For the same reason, it is preferable that the amount of residual solvent is dried to less than 2% by mass, preferably less than 0.4% by mass immediately before the heat treatment step.

The heat treatment is performed by a method of applying a wind at a predetermined temperature to the film being conveyed or a method using a heating means such as a microwave.
The heat treatment is preferably performed at a temperature of 150 to 200 ° C., more preferably 160 to 180 ° C. The heat treatment is preferably performed for 1 to 20 minutes, more preferably 5 to 10 minutes.

<Heating steam treatment process>
In addition, the stretched film may be manufactured through a process of spraying steam heated to 100 ° C. or higher. By passing through this water vapor spraying step, the residual stress of the manufactured optical film is relaxed, and the dimensional change is reduced, which is preferable. The temperature of the water vapor is not particularly limited as long as it is 100 ° C. or higher, but considering the heat resistance of the film, the temperature of the water vapor is 200 ° C. or lower.

<Surface treatment process>
When the optical film of the present invention is used as a protective film for a polarizing plate and adhered to a polarizer, the surface of acid treatment, alkali treatment, plasma treatment, corona treatment, etc. is used from the viewpoint of adhesion to the polarizer. It is particularly preferred to carry out the treatment to make it hydrophilic.
Among them, since the optical film of the present invention has an outer layer of cellulose acylate on both sides of the core layer, the outer layer of cellulose acylate is alkali saponified and bonded to a commonly used polyvinyl alcohol polarizer. It is preferable to improve. Without an outer layer, it is necessary to use an adhesive, which is disadvantageous because of poor production efficiency.

[Polarizer]
The polarizing plate of the present invention includes a polarizer and the optical film of the present invention.
The optical film of the present invention can be used as a protective film in a polarizing plate having a polarizer and a protective film disposed on at least one side thereof.

  Moreover, in the form which arrange | positions a protective film on both surfaces of a polarizer as a structure of a polarizing plate, it can also be used as one protective film or retardation film.

  Examples of the polarizer include an iodine polarizing film, a dye polarizing film using a dichroic dye, and a polyene polarizing film. The iodine-based polarizing film and the dye-based polarizing film can be generally produced using a polyvinyl alcohol film.

[Liquid Crystal Display]
The liquid crystal display device of the present invention uses the optical film of the present invention or the polarizing plate of the present invention.
The optical film and the polarizing plate can be advantageously used for an image display device such as a liquid crystal display device, and are preferably used for the outermost layer on the backlight side.

  In general, a liquid crystal display device has a liquid crystal cell and two polarizing plates arranged on both sides thereof, and the liquid crystal cell carries a liquid crystal between two electrode substrates. Furthermore, one optically anisotropic layer may be disposed between the liquid crystal cell and one polarizing plate, or two optically anisotropic layers may be disposed between the liquid crystal cell and both polarizing plates.

  The liquid crystal cell is preferably in the TN mode, VA mode, OCB mode, IPS mode or ECB mode, and more preferably in the IPS mode.

The optical film of the present invention can be preferably used particularly for an IPS mode liquid crystal display device. The optical film of the present invention is preferable in the IPS mode liquid crystal display device because both the in-plane retardation Re and the thickness direction retardation Rth can be easily reduced.
The optical film of the present invention can remarkably improve the circular color change in the lick direction of the liquid crystal display device having a specific structure. That is, in the liquid crystal display device of the present invention, the distance between the surface of the backlight side polarizing plate and the film member on the backlight side is preferably 0 mm or less.

  The film member on the backlight side is a generic term for a brightness enhancement film that efficiently uses the light of the backlight unit, a prism sheet that collects light, a microlens sheet, and a diffusion sheet that has a light diffusion function. To tell. Here, the order of lamination and the number of the laminated film members on the backlight side are not limited, and the liquid crystal display device of the present invention is arranged on the side closest to the liquid crystal panel. The distance from the backlight side polarizing plate surface is preferably 10 mm or less.

  The features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below. Unless otherwise specified, “part” is based on mass.

[Comparative Example 1]
(Adjustment of dope solution A-0)
100 parts by mass of cellulose acetate having a degree of acetyl substitution of 2.86 (weight average molecular weight 220,000, hereinafter also referred to as cellulose acetate 1) is dissolved in a mixed solvent of methylene chloride: methanol (weight ratio 80:20), and a dope solution A -0 was obtained. This dope A-0 was cast from a die onto a metal support. While on the metal support, the dope was dried with a drying air at 40 ° C. to form a film, and then peeled off. Both ends of the film were fixed with pins, and 5 ° C. with a drying air of 105 ° C. while maintaining the same interval. Dried for minutes. After removing the pins, the film was further dried at 130 ° C. for 20 minutes to obtain a film having a thickness of 50 μm consisting of only the core layer. This was used as the optical film of Comparative Example 1.

(Evaluation of optical properties)
After adjusting the sample film for 24 hours at 25 ° C. and 60% relative humidity, the film surface was measured using an automatic birefringence meter (KOBRA-21ADH: manufactured by Oji Scientific Instruments) at 25 ° C. and 60% relative humidity. The phase difference at a wavelength of 590 nm was measured from the direction inclined in increments of 10 ° from + 50 ° to −50 ° from the normal to the film surface with the vertical direction and the slow axis as the rotation axis. ) And the retardation value (Rth) in the film thickness direction.
Regarding the change of the retardation value with humidity, Rth calculated and measured in the same manner as above except that the film was conditioned at 25 ° C. and 10% relative humidity for 12 hours, and 25 ° C. The humidity dependence of Rth was calculated from Rth measured and calculated in the same manner as described above except that the humidity was adjusted at 80% relative humidity for 12 hours.
The optical film of Comparative Example 1 was measured for Rth when the relative humidity was 10% and Rth when the relative humidity was 80%, and the humidity dependency ΔRth (10 A% -80%) was determined to be 28 nm.
The results are shown in Table 1 below.

[Comparative Example 2]
(Preparation of dope solution B-1)
PMMA1, which is polymethyl methacrylate having a weight average molecular weight of 1,500,000, is used as an acrylic resin, dissolved in a mixed solvent of methylene chloride: methanol (weight ratio 80:20), and a dope solution B-1 (solid content concentration 22%, complex) A viscosity of 50 Pa · s) was obtained.

(Production of optical film)
In Comparative Example 1, except that the dope solution B-1 prepared above was used for the core layer instead of the above dope solution A-0, and a single-layer solution film formation consisting only of acrylic dope was used. The optical film of Comparative Example 2 was produced by the same operation as the production of the optical film.
This was used as the optical film of Comparative Example 2.

[Comparative Example 3]
(Production of optical film)
Using the dope solution A-0 prepared above as an outer layer and the dope solution B-1 prepared above as a core layer, a solution casting film was formed, and a comparative example having the configuration shown in Table 1 below. 3 optical films were produced. Specifically, continuous film formation was performed on a metal support from a die capable of co-casting at the same time in three layers so as to have the layer configuration shown in Table 1 below, and from the metal support surface side, the outer layer A- The thickness of each layer was cast as shown in Table 1 below so as to be 0, core layer B-1, and outer layer A-0. The film thickness configuration is a converted film thickness when it is assumed that a film having a uniform thickness is formed from each dope flow rate. While on the metal support, the dope was dried with a drying air at 40 ° C. to form a film, and then peeled off. Both ends of the film were fixed with pins, and 5 ° C. with a drying air of 105 ° C. while maintaining the same interval. Dried for minutes. After removing the pin, it was further dried at 130 ° C. for 20 minutes.
This was designated as the optical film of Comparative Example 3.

[Example 1]
(Synthesis of Compound (2-2) which is a Humidity Dependence Improvement Agent)
To a solution of 10 g (81 mmol) of 2,4-diamino-6-methylpyrimidine in 100 mL of N-ethylpyrrolidone, 23 g (169 mmol) of methyl m-methylbenzoate and 22 g (407 mmol) of sodium methoxide were added, and the mixture was heated at 40 ° C. for 2 hours. Stir with heating. The temperature of the reaction system was returned to room temperature, the reaction solution was poured into a 1N aqueous hydrochloric acid solution, and the solid was collected by filtration. The obtained crude product was recrystallized from 2-propanol to obtain a compound (2-2).
The NMR spectrum of the obtained compound (2-2) is as follows.
¹ H-NMR (solvent: heavy DMSO, standard: tetramethylsilane) δ (ppm)
2.38 (6H, s)
2.50 (3H, s)
7.36-7.47 (4H, m)
7.70-7.90 (5H, m)
10.77 (1H, s)
10.99 (1H, s)

(Performance Evaluation of Humidity Dependency Improvement Effect of Compound (2-2))
3 parts by mass of this compound (2-2) and 100 parts by mass of acetyl cellulose (the cellulose acetate 1) having an acetyl substitution degree of 2.86 were dissolved in a mixed solvent of methylene chloride: methanol (weight ratio 80:20), A 50 μm film was prepared in the same manner as in Comparative Example 1. The humidity dependency ΔRth (10% -80%) at this time was measured and found to be 17 nm. The difference from the humidity dependence ΔRth (10% -80%) of the cellulose acetate film having an acetyl substitution degree of 2.86 without addition of an additive having a film thickness of 50 μm in Comparative Example 1 was −11 nm. That is, the performance of the compound (2-2) calculated on the left side of the formula (I) was -11 nm.

(Preparation of dope solution A-1)
A mixed solvent of methylene chloride: methanol (weight ratio 80:20) was prepared by adding 100 parts by mass of acetyl cellulose (cellulose acetate 1) having a degree of acetyl substitution of 2.86 and 3 parts by mass of the compound (2-2) synthesized in Synthesis Example 1. To obtain a dope solution A-1 (solid content concentration 18% by mass, complex viscosity 15 Pa · s).

(Production of optical film)
Using the dope solution A-1 as an outer layer and the dope solution B-1 as a core layer, an optical film of Example 1 was prepared in the same manner as the optical film of Comparative Example 3 except that.

[Example 2]
(Synthesis of Compound (2-9) which is a Humidity Dependence Improvement Agent)
To a solution of 10 g (81 mmol) of 2,4-diamino-6-methoxypyrimidine in 100 mL of N-ethylpyrrolidone, 23 g (169 mmol) of methyl m-methylbenzoate and 22 g (407 mmol) of sodium methoxide were added, and the mixture was heated at 40 ° C. for 2 hours. Stir with heating. The temperature of the reaction system was returned to room temperature, the reaction solution was poured into a 1N aqueous hydrochloric acid solution, and the solid was collected by filtration. The obtained crude product was recrystallized from 2-propanol to obtain a compound (2-9).
The NMR spectrum of the obtained compound (2-9) is as follows.
¹ H-NMR (solvent: heavy DMSO, standard: tetramethylsilane) δ (ppm)
2.40 (6H, s)
3.92 (3H, s)
7.35-7.45 (5H, m)
7.73-7.87 (4H, m)
10.67 (1H, s)
10.88 (1H, s)

(Performance Evaluation of Humidity Dependence Improvement Effect of Compound (2-9))
3 parts by mass of this compound (2-9) and 100 parts by mass of acetyl cellulose (the cellulose acetate 1) having an acetyl substitution degree of 2.86 were dissolved in a mixed solvent of methylene chloride: methanol (weight ratio 80:20), The humidity dependency ΔRth (10% -80%) when a film of 50 μm was formed in the same manner as in Comparative Example 1 was 19 nm. The difference from the humidity dependence ΔRth (10% -80%) of the cellulose acetate film having an acetyl substitution degree of 2.86 without addition of an additive having a film thickness of 50 μm in Comparative Example 1 was −9 nm. That is, the performance of the compound (2-9) calculated on the left side of the formula (I) was −9 nm.

(Preparation of dope solution A-2)
In the production of the optical film of Example 1, the dope solution A-2 (solid content concentration of 18) was obtained by replacing the compound (2-2) used in the dope solution A-1 with the compound (2-9) synthesized in Synthesis Example 1. Mass%, complex viscosity 15 Pa · s) was prepared.

(Production of optical film)
In the production of the optical film of Example 1, the optical film of Example 2 was produced by the same operation except that the dope solution A-2 prepared above was used instead of the dope solution A-1.

[Example 3]
(Adjustment of dope solutions A-3 and B-2)
In the production of the optical film of Example 2, 10 parts by mass of the following compound A was further added to the dope solution A-2 and the dope solution B-1, and the dope solution A-3 (solid content concentration: 18% by mass, complex viscosity: 14 Pa). S) and B-2 (solid content concentration 22% by mass, complex viscosity 45 Pa · s) were prepared.

（上記繰り返し単位のオリゴマー、重量平均分子量１０００）

(Oligomer of the above repeating unit, weight average molecular weight 1000)

(Production of optical film)
In the production of the optical film of Example 1, the dope solution A-3 prepared above was used instead of the dope solution A-1, and the dope solution B-2 prepared above was used instead of the dope solution B-1. An optical film of Example 3 was produced by the same operation except that it was used.

[Example 4]
(Preparation of dope solution A-4)
In preparation of the optical film of Example 3, the compound (2-9) used for the cellulose acylate solution A-3 was changed from 3 parts by mass to 6 parts by mass, and the cellulose acylate solution A-4 (solid content concentration 18 masses) was obtained. %, Complex viscosity 14 Pa · s).

(Production of optical film)
In the production of the optical film of Example 1, the dope solution A-4 prepared above was used instead of the dope solution A-1, and the dope solution B-2 prepared above was used instead of the dope solution B-1. An optical film of Example 4 was produced in the same manner except that it was used.

[Comparative Example 4]
(Synthesis of Comparative Compound A-2)
The following comparative compound A-2 (compound described in JP 2007-138119 A) was synthesized by the method described in Gazzetta Chimica Italiana (1935), 65 566-88.

(Performance evaluation of humidity dependency improving effect of Comparative Compound A-2)
3 parts by mass of this comparative compound A-2 and 100 parts by mass of acetyl cellulose (cellulose acetate 1) having an acetyl substitution degree of 2.86 were dissolved in a mixed solvent of methylene chloride: methanol (weight ratio 80:20), and compared. When the humidity dependency ΔRth (10% -80%) was measured in the same manner as in Example 1 for a 50 μm film, it was 24.5 nm. The difference from the humidity dependence ΔRth (10% -80%) of the cellulose acetate film having an acetyl substitution degree of 2.86 without addition of an additive having a film thickness of 50 μm in Comparative Example 1 was −3.5 nm. That is, the performance of the comparative compound A-2 calculated on the left side of the formula (I) was −3.5 nm.

(Production of optical film)
The optical film of Comparative Example 4 was prepared in the same manner as in the production of the optical film of Example 1, except that the compound (1) used in the dope solution A-1 was changed to the comparative compound A-2 synthesized above. Produced.

[Comparative Example 5]
(Production of optical film)
In the production of the optical film of Example 3, the optical film of Comparative Example 5 was produced in the same manner as in the preparation of the dope solution A-3 except that the compound (2-9) was not added.

[Comparative Example 6]
(Performance evaluation of humidity dependency improvement effect of Comparative Compound 2)
As Comparative Compound 2, TPP (triphenyl phosphate) generally used as a phosphate ester plasticizer for a general cellulose acylate film was used.
In Comparative Example 1, 3 parts by mass of this comparative compound 2 and 100 parts by mass of acetyl cellulose (cellulose acetate 1) having a degree of acetyl substitution of 2.86 were dissolved in a mixed solvent of methylene chloride: methanol (weight ratio 80:20). The humidity dependency ΔRth (10% -80%) when a 50 μm film was obtained in the same manner as described above was 27 nm. The difference from the humidity dependency ΔRth (10% -80%) of the cellulose acetate film having an acetyl substitution degree of 2.86 without addition of an additive having a film thickness of 50 μm in Comparative Example 1 was −1.0 nm. That is, the performance of the comparative compound A-2 calculated on the left side of the formula (I) was -1.0 nm.

(Production of optical film)
An optical film of Comparative Example 5 was produced in the same manner as in the production of the optical film of Example 1, except that the compound (1) used in the dope solution A-1 was changed to the comparative compound 2 synthesized above. .

[Evaluation]
(Re, Rth and Rth humidity dependence (ΔRth))
In the same manner as in Comparative Example 1, the retardation values of the optical films of each Example and Comparative Example were measured, and then the value of ΔRth was obtained.
The obtained results are shown in Table 1 below.

(Photoelastic coefficient)
A 1 cm × 5 cm sample was cut out from each of the produced optical films of Examples and Comparative Examples, and a film surface was applied while applying stress to the sample at 25 ° C. using a spectroscopic ellipsometer (M-220, manufactured by JASCO Corporation). The retardation value was measured and calculated from the slope of the function of retardation value and stress.
The obtained results are shown in Table 1 below.

(Preparation of polarizing plate)
After immersing each optical film and Fujitac TD60UL (manufactured by FUJIFILM Corporation) prepared in Examples and Comparative Examples in a 4.5 mol / L sodium hydroxide aqueous solution (saponification solution) adjusted to 37 ° C. for 1 minute, The film was washed with water, then immersed in a 0.05 mol / L sulfuric acid aqueous solution for 30 seconds, and then passed through a washing bath. Then, draining with an air knife was repeated three times, and after dropping the water, the film was retained in a drying zone at 70 ° C. for 15 seconds and dried to produce a saponified film.
According to Example 1 of Japanese Patent Laid-Open No. 2001-141926, a peripheral speed difference was given between two pairs of nip rolls, and the film was stretched in the longitudinal direction to prepare a polarizer having a thickness of 20 μm.
Two polarizers were selected from the polarizer thus obtained and the saponified film, and the polarizer was sandwiched between them. Then, a 3% aqueous solution of PVA (manufactured by Kuraray Co., Ltd., PVA-117H) was used as an adhesive. As a polarizing plate, a polarizing plate was prepared by roll-to-roll bonding so that the polarizing axis and the longitudinal direction of the film were orthogonal to each other. Here, one film of the polarizer was a saponified film selected from the film group shown in Table 2, and the other film was Fujitac TD60UL.

(Evaluation of bonding to PVA polarizer)
At this time, the results of evaluating the bonding to the PVA polarizer according to the following criteria are shown in Table 1 below.
○: The film does not peel from the polyvinyl alcohol.
X: A film peels easily from polyvinyl alcohol.

(Mounting evaluation on liquid crystal display devices)
(Mounting on IPS liquid crystal display)
Strip the polarizing plate sandwiching the liquid crystal cell from a commercially available liquid crystal television (IPS mode slim 42-inch liquid crystal television. The distance between the backlight side polarizing plate surface and the backlight is 1.5 mm). The produced polarizing plate was re-bonded to the liquid crystal cell via an adhesive so that the optical film side of the present invention described in Table 1 below was disposed on the liquid crystal cell side. The reassembled LCD TV was kept in an environment of 40 ° C. and 80% relative humidity for 10 days, then moved to an environment of 25 ° C. and 60% relative humidity, kept on in a black display state, and visually observed after 48 hours. The color change was evaluated.

(Color change in the lick direction)
The change in tint when observed from the device licking direction was observed and evaluated according to the following criteria. The results are shown in Table 1 below.
○: Circular color change is hardly visible.
X: Although the circular color change is faint, it is clearly visible.
XX: A circular color change is visually recognized.

From Table 1, it was found that the optical films of Examples 1 to 4 have small Rth humidity dependency and good bonding with the polarizer. That is, in the case of the polarizing plate using the optical film of the present invention, the adhesive property of the polarizer was excellent, the bonding property with polyvinyl alcohol was sufficient, and the polarizing plate had excellent processing suitability.
Moreover, the liquid crystal display device of each Example which incorporated the polarizing plate using the optical film of Examples 1-4 in a liquid crystal display device is each which incorporated the polarizing plate using the optical film of each comparative example in the liquid crystal display device. As compared with the liquid crystal display device of the comparative example, it was found that the circular color change evaluation performance was excellent when the panel was observed from the licking direction.
A core layer dope containing acrylic similar to that of Example 1 was prepared using an acrylic resin having a weight average molecular weight of 100,000. The film was formed by co-casting with the outer layer dope because of insufficient viscosity. Compared with Example 1, the surface shape was not smooth, and there was a problem from the viewpoint of smoothness.

  Comparative Example 1 was a cellulose acylate monolayer film, and the humidity dependency of Rth was large, and it was found that the evaluation of the circular color change in the lick direction when incorporated in a panel was poor. Comparative Example 2 was an acrylic single layer film, and a polarizing plate could not be produced because there was a problem with the adhesive force in the bonding process with ordinary PVA, and panel mounting was not possible. Comparative Example 3 is an embodiment in which no additive is added to the outer cellulose acylate layer, the humidity dependency of Rth is large, and the circular color change evaluation in the lick direction when incorporated in a panel is poor. all right. Comparative Example 4 is an embodiment in which a humidity dependency improving agent having a performance equal to or less than the performance specified in the present invention is added to the outer cellulose acylate layer. Rth has a large humidity dependency and has a circular shape in a licking direction when incorporated in a panel. It was found that the color change evaluation of was bad. Comparative Example 5 is an embodiment in which compound A was added to the cellulose acylate layer and the (meth) acrylic layer without adding a humidity dependency improving agent, and the humidity dependency of Rth was large. It was found that the evaluation of the circular color change in the direction was bad. Comparative Example 6 is an embodiment in which a general plasticizer is added in place of the humidity dependency improving agent for performance defined in the present invention. Rth has a large humidity dependency, and the circle in the licking direction when incorporated in a panel. It was found that the color change evaluation of the shape was bad.

11 Casting equipment 12 Dope 14 Casting die 31 Band 32 Backup roller 33 Backup roller 36 Film 37 Stripping roller 51 Temperature control plate 52 Condensing plate 53 Liquid receiver 56 Recovery tank 101 Casting equipment 102 Drum 105 Condensing plate PS Start of casting position

Claims (21)

It consists of three layers: outer layer / core layer / outer layer,
The core layer contains (meth) acrylic resin as a main component,
An optical film characterized in that the outer layer contains a humidity dependency improving agent satisfying the following formula (I) and contains cellulose acylate as a main component.
Formula (I) ΔRth (3) ≦ −4 nm
Formula (I ′) ΔRth (3) = (ΔRth (rh, 3) −ΔRth (rh, 0)
(In the formula (I), ΔRth (rh, 3) is a temperature of 25 ° C. of a 50 μm-thick film obtained by adding 3 parts by mass of a humidity dependency improver to 100 parts by mass of cellulose acetate having an acetyl substitution degree of 2.86. Represents a value obtained by subtracting Rth at 25 ° C. and 80% relative humidity from Rth at 10% humidity.ΔRth (rh, 0) is a cellulose having an acetyl substitution degree of 2.86 to which no humidity-dependent improving agent is added. This is a value obtained by subtracting Rth at 25 ° C. and relative humidity of 80% from Rth at 25 ° C. and relative humidity of 10% of a 50 μm-thick film of acetate, where Rth is the retardation in the film thickness direction of the film at a wavelength of 590 nm ( (Unit: nm) The optical film according to claim 1, wherein ΔRth (10% -80%) defined by the following formula (II) is −10 to 5 nm.
Formula (II) ΔRth (10% -80%) = Rth (10%)-Rth (80%)
(In the formula (II), Rth (10%) represents the value of retardation Rth in the film thickness direction at a film wavelength of 590 nm, 25 ° C. and 10% relative humidity. Rth (80%) represents the film wavelength of 590 nm. Represents the value of retardation Rth in the film thickness direction at 25 ° C. and 80% relative humidity.)   3. The optical film according to claim 1, wherein the (meth) acrylic resin as a main component of the core layer has a weight average molecular weight of 800,000 to 2,000,000. The optical film according to any one of claims 1 to 3, wherein the humidity dependency improving agent is at least one compound represented by the following general formula (1):

In general formula (1), Y represents a methine group or a nitrogen atom; Q ^a , Q ^b, and Q ^c each represent a single bond or a divalent linking group; R ^a , R ^b , and R ^c each represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a cyano group, a halogen group or a heterocyclic group, R ^a and R ^b may be linked to form a ring; X ² is a single Represents a bond or a divalent linking group, and X ¹ represents a single bond or the following divalent linking group group (5):

(In each formula, the * side is the linking site with the N atom substituted on the 1,3,5-triazine ring in the compound represented by each formula; R ^g is an alkyl group, an alkenyl group, an alkynyl group; Represents a divalent group selected from: R ¹ and R ² each represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group. And may be connected to each other to form a ring. The said humidity dependence improving agent is at least 1 sort (s) of the compound represented by the following general formula (101) or general formula (102), The optical as described in any one of Claims 1-3 characterized by the above-mentioned. the film.

(In the general formula (101), R _A represents an alkyl group, an alkenyl group, an alkynyl group, a heterocyclic group or an aryl group. X ¹⁰¹ , X ¹⁰² , X ¹⁰³ and X ¹⁰⁴ are each independently a single bond or a divalent group. And R ¹⁰¹ , R ¹⁰² , R ¹⁰³ and R ¹⁰⁴ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an acyl group or a heterocyclic group.

(In the general formula (102), R _B and R _C each independently represents an alkyl group, an alkenyl group, an alkynyl group, a heterocyclic group or an aryl group. X ¹⁰⁵ and X ¹⁰⁶ each independently represent a single bond or a divalent group. R ¹⁰⁵ and R ¹⁰⁶ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an acyl group or a heterocyclic group. The X ^{101 to} X ¹⁰⁶ in the general formula (101) or (102) are each independently selected from a single bond or a group represented by the following general formula (103). Optical film.
General formula (103)

  The optical film according to claim 1, wherein a total film thickness of the outer layer is 20 μm or less.   The optical film according to claim 1, wherein the core layer has a thickness of 10 to 100 μm.   The ratio of the total film thickness of the said outer layer which occupies for the whole film thickness is 2 to 40%, The optical film as described in any one of Claims 1-8 characterized by the above-mentioned. The value according to claim 1, wherein the photoelastic coefficient is −3.0 × 10 ⁻¹² Pa ^{−1 to} 3.0 × 10 ⁻¹² Pa ^−1. the film. 5nm <| Rth |
A dope (A) containing a cellulose acylate, a humidity dependence improver satisfying the following formula (I) and an organic solvent, and a dope (B) containing a (meth) acrylic resin and an organic solvent are cast into a base material. The manufacturing method of the optical film characterized by including the process of casting on a casting base material simultaneously by the co-casting method in order of (A)-(B)-(A) from the side.
Formula (I) ΔRth (3) ≦ −4 nm
Formula (I ′) ΔRth (3) = (ΔRth (rh, 3) −ΔRth (rh, 0)
(In the formula (I), ΔRth (rh, 3) is a temperature of 25 ° C. of a 50 μm-thick film obtained by adding 3 parts by mass of a humidity dependency improver to 100 parts by mass of cellulose acetate having an acetyl substitution degree of 2.86. Represents a value obtained by subtracting Rth at 25 ° C. and 80% relative humidity from Rth at 10% humidity.ΔRth (rh, 0) is a cellulose having an acetyl substitution degree of 2.86 to which no humidity-dependent improving agent is added. This is a value obtained by subtracting Rth at 25 ° C. and relative humidity of 80% from Rth at 25 ° C. and relative humidity of 10% of a 50 μm-thick film of acetate, where Rth is the retardation in the film thickness direction of the film at a wavelength of 590 nm ( (Unit: nm)   The method for producing an optical film according to claim 11, wherein the (meth) acrylic resin contained in the dope (B) has a weight average molecular weight of 800,000 to 2,000,000.   The method for producing an optical film according to claim 11 or 12, wherein the casting thickness of the dope (A) is controlled so that the total dry thickness of the dope (A) is 20 µm or less. A complex viscosity eta _A of the dope (A), the complex viscosity eta _B of the dope (B), and controls so as to satisfy the relationship of formula (III), any claim 11 to 13 The method for producing an optical film according to claim 1.
Formula (III) η _A ≦ η _B   The method for producing an optical film according to claim 11, wherein the dope (A) and the dope (B) each have a complex viscosity at 25 ° C. of 10 to 80 Pa · s. .   The method for producing an optical film according to any one of claims 11 to 15, wherein the dope (A) has a solid content concentration of 15 to 25% by mass.   The optical film manufactured by the manufacturing method of the optical film as described in any one of Claims 11-16.   A polarizing plate comprising a polarizer and the optical film according to claim 1.   A liquid crystal display device comprising the optical film according to any one of claims 1 to 10 and the polarizing plate according to claim 18.   The liquid crystal display device according to claim 19, wherein the liquid crystal display device is an IPS system.   21. The liquid crystal display device according to claim 19, wherein a distance between the surface of the backlight side polarizing plate and the film member on the backlight side is 10 mm or less.

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