JP2013101328A - Polarizing film, circularly polarizing plate and their manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarizing film and the like having a thin film and high polarization performance, being useful for a member for a display device.SOLUTION: A polarizing film is formed from a composition containing at least one kind of polyazo-based dye having absorption in a wavelength ranging from 400 to 800 nm and represented by the following general formula (1) and a polymerizable smectic liquid crystal compound. A liquid crystal display device comprises the polarizing film. In the formula (1), Aris selected from the groups shown below. The polymerizable smectic liquid crystal compound is preferably a compound exhibiting the liquid crystal state of higher smectic phase.

Description

  The present invention relates to a polarizing film, a circularly polarizing plate, a manufacturing method thereof, and the like.

  As a polarizer used in a liquid crystal display device, a film made of polyvinyl alcohol dyed with iodine is usually used. On the other hand, recent liquid crystal display devices are strongly required to be thin, and accordingly, a thinner polarizer is also required. As for the thin polarizing film which a thin polarizer has, what is formed from the composition containing a polymerizable nematic liquid crystal compound and a dichroic dye is described in patent document 1, for example. As the dichroic dye, for example, Patent Document 2 describes a specific polyazo dye for use in forming a polarizing film by vapor deposition.

Special table 2007-510946 gazette JP-A-8-278409

  It is desirable that the polarizing film that is required to be a thin film has high polarization performance, particularly high dichroic ratio.

［式（１）中、
ｎは１又は２である。
Ａｒ_１及びＡｒ_３は、それぞれ独立に下記に示す基から選ばれる基を表す。

Ａｒ_２は下記に示す基から選ばれる基を表す。

Ａ_１及びＡ_２は、それぞれ独立に下記に示す基から選ばれる基を表す。

（ｍは０〜１０の整数であり、同一の基中にｍが２つある場合、この２つのｍは互いに同一又は相異なる。）］
〔２〕厚みが、１μｍ以上１０μｍ以下である前記〔１〕記載の偏光膜。
〔３〕Ｘ線回折測定においてブラッグピークが得られる前記〔１〕又は〔２〕記載の偏光膜。
〔４〕前記〔１〕〜〔３〕のいずれか記載の偏光膜、配向膜及び透明基材をこの順で備えた偏光子。
〔５〕前記〔１〕〜〔３〕のいずれか記載の偏光膜、配向膜及び透明基材をこの順で備えた偏光子の製造方法であり、
前記透明基材上に、前記配向膜を備えた積層体を準備する工程と、
前記積層体の前記配向膜上に、重合性スメクチック液晶化合物、波長４００〜８００ｎｍの範囲に吸収を有し、前記一般式（１）で表されるポリアゾ系色素、重合開始剤及び溶剤を含む膜を形成する工程と、
前記膜から前記溶剤を除去する工程と、
前記溶剤を除去した膜に含まれる前記重合性スメクチック液晶化合物をスメクチック液晶状態とする工程と、
前記重合性スメクチック液晶化合物が前記スメクチック液晶状態を保持したまま、前記重合性スメクチック液晶化合物を重合させることにより、前記配向膜上に偏光膜を形成する工程とを有する製造方法。
〔６〕前記〔１〕〜〔３〕のいずれか記載の偏光膜を備えた液晶表示装置。
〔７〕前記〔１〕〜〔３〕のいずれか記載の偏光膜と、λ/４層とを有し、以下の（Ａ１）及び（Ａ２）の要件を満たす円偏光板。
（Ａ１）前記偏光膜の吸収軸と、前記λ/４層の遅相軸とのなす角度が、略４５°であること；
（Ａ２）波長５５０ｎｍの光で測定した、前記λ/４層の正面リタデーションの値が１００〜１５０ｎｍの範囲であること
〔８〕前記〔１〕〜〔３〕のいずれか記載の偏光膜と、λ/２層と、λ/４層とをこの順で有し、以下の（Ｂ１）、（Ｂ２）、（Ｂ３）及び（Ｂ４）の要件を満たす円偏光板。
（Ｂ１）前記偏光膜の吸収軸と、前記λ/２層の遅相軸とのなす角度が、略１５°であること；
（Ｂ２）前記λ/２層の遅相軸と、前記λ/４層の遅相軸とのなす角度が、略６０°であること；
（Ｂ３）前記λ/２層が、波長５５０ｎｍの光で測定した、前記λ/４層の正面リタデーションの値が２００〜３００ｎｍの範囲であること；
（Ｂ４）前記λ/４層が、波長５５０ｎｍの光で測定した、前記λ/４層の正面リタデーションの値が１００〜１５０ｎｍの範囲であること
〔９〕前記〔７〕又は〔８〕記載の円偏光板と、有機ＥＬ素子とを備えた有機ＥＬ表示装置。 The present invention includes the following inventions.
[1] At least one polyazo dye having absorption in the wavelength range of 400 to 800 nm and represented by the following general formula (1):
A polarizing film formed from a composition containing a polymerizable smectic liquid crystal compound.

[In Formula (1),
n is 1 or 2.
Ar ₁ and Ar ₃ each independently represent a group selected from the groups shown below.

Ar ₂ represents a group selected from the following groups.

A ₁ and A ₂ each independently represent a group selected from the following groups.

(M is an integer of 0 to 10, and when there are two m's in the same group, these two m's are the same or different from each other.)]
[2] The polarizing film according to [1], wherein the thickness is 1 μm or more and 10 μm or less.
[3] The polarizing film according to [1] or [2], wherein a Bragg peak is obtained in X-ray diffraction measurement.
[4] A polarizer comprising the polarizing film according to any one of [1] to [3], an alignment film, and a transparent substrate in this order.
[5] A method for producing a polarizer comprising the polarizing film according to any one of [1] to [3], an alignment film, and a transparent substrate in this order,
On the transparent substrate, preparing a laminate including the alignment film;
A film containing a polymerizable smectic liquid crystal compound, a polyazo dye represented by the general formula (1), a polymerization initiator and a solvent, on the alignment film of the laminate, having absorption in the wavelength range of 400 to 800 nm. Forming a step;
Removing the solvent from the film;
A step of bringing the polymerizable smectic liquid crystal compound contained in the film from which the solvent has been removed into a smectic liquid crystal state;
A process comprising: forming a polarizing film on the alignment film by polymerizing the polymerizable smectic liquid crystal compound while the polymerizable smectic liquid crystal compound maintains the smectic liquid crystal state.
[6] A liquid crystal display device comprising the polarizing film according to any one of [1] to [3].
[7] A circularly polarizing plate having the polarizing film according to any one of [1] to [3] and a λ / 4 layer and satisfying the following requirements (A1) and (A2).
(A1) The angle formed by the absorption axis of the polarizing film and the slow axis of the λ / 4 layer is approximately 45 °;
(A2) The value of the front retardation of the λ / 4 layer measured with light having a wavelength of 550 nm is in the range of 100 to 150 nm. [8] The polarizing film according to any one of [1] to [3], A circularly polarizing plate having a λ / 2 layer and a λ / 4 layer in this order and satisfying the following requirements (B1), (B2), (B3), and (B4).
(B1) The angle formed by the absorption axis of the polarizing film and the slow axis of the λ / 2 layer is approximately 15 °;
(B2) The angle formed between the slow axis of the λ / 2 layer and the slow axis of the λ / 4 layer is approximately 60 °;
(B3) The value of the front retardation of the λ / 4 layer measured with light having a wavelength of 550 nm is in the range of 200 to 300 nm.
(B4) The λ / 4 layer is measured with light having a wavelength of 550 nm, and the front retardation value of the λ / 4 layer is in the range of 100 to 150 nm. [9] The above [7] or [8] An organic EL display device comprising a circularly polarizing plate and an organic EL element.

  According to the present invention, a thin polarizing film having a high dichroic ratio, a polarizer including the polarizing film, a liquid crystal display device, a circularly polarizing plate, and an organic EL display device can be provided.

It is a schematic cross section which shows the principal part of the continuous manufacturing method (Roll to Roll format) of this polarizing film. It is a schematic cross section which shows the cross-sectional structure of the liquid crystal display device using the polarizer containing this polarizing film. It is an expansion schematic cross section which shows the layer order of the polarizer containing this polarizing film provided in the liquid crystal display device. It is an expansion schematic cross section which shows the layer order of the polarizer containing this polarizing film provided in the liquid crystal display device. It is a schematic cross section which shows the cross-sectional structure of the liquid crystal display device (in-cell format) using the polarizer containing this polarizing film. It is a cross-sectional schematic diagram which shows the simplest structure of the circularly-polarizing plate containing this polarizing film. It is a schematic cross section which shows the principal part of the continuous manufacturing method of the circularly-polarizing plate containing this polarizing film. It is a schematic cross section which shows the cross-sectional structure of EL display apparatus using the circularly-polarizing plate containing this polarizing film. It is an expansion schematic cross section which shows the layer order of the circularly-polarizing plate containing this polarizing film provided in EL display apparatus. It is a schematic cross section which shows the cross-sectional structure of EL display apparatus using the circularly-polarizing plate containing this polarizing film. It is a schematic cross section which shows the cross-sectional structure of the projection-type liquid crystal display device using the polarizer containing this polarizing film.

  The polarizing film of the present invention (hereinafter sometimes referred to as “the present polarizing film”) is a composition containing the polyazo dye represented by the formula (1) and a polymerizable smectic liquid crystal compound (hereinafter referred to as occasion demands). (Referred to as “polarizing film forming composition”). This polarizing film is not only suitably used for a liquid crystal display device, but also by using this polarizing film as will be described later, a polarizer suitably used for an organic EL display device (hereinafter sometimes referred to as “the present polarizer”). Or a circularly polarizing plate (hereinafter sometimes referred to as “the present circularly polarizing plate”). Hereinafter, this polarizing film and its manufacturing method, this polarizer and its manufacturing method, and this circularly-polarizing plate and its manufacturing method are demonstrated, referring drawings as needed. Note that the dimensions of the drawings attached to the present specification are arbitrary for easy viewing.

<Polyazo dye>
The polyazo dye (hereinafter sometimes referred to as “azo dye (1)”) used in the production of the polarizing film is represented by the formula (1), and the azo dye (1) is within a wavelength range of 400 to 800 nm. Has absorption.

  The positional isomerism of the azobenzene moiety of the azo dye (1) is preferably trans.

Examples of the azo dye (1) include compounds represented by formulas (1-1) to (1-27).

  Among the specific examples of the azo dye (1), the formula (1-2), the formula (1-5), the formula (1-6), the formula (1-8), the formula (1-10), and the formula (1-12), formula (1-13), formula (1-15), formula (1-16), formula (1-19), formula (1-20), formula (1-21), formula ( 1-22), Formula (1-23), Formula (1-24), and Formula (1-26) are more preferable than those respectively represented by Formula (1-2), Formula (1-5), Formula ( 1-8), Formula (1-10), Formula (1-15), Formula (1-21), Formula (1-22), and Formula (1-26) are particularly preferable.

  The content of the azo dye (1) in the polarizing film-forming composition is preferably 50 parts by mass or less, preferably 0.1 parts by mass or more and 20 parts by mass with respect to 100 parts by mass of the polymerizable smectic liquid crystal compound described later. The amount is more preferably equal to or less than mass parts, and further preferably equal to or greater than 0.1 mass parts and equal to or less than 10 mass parts. Within the above range, there is an advantage that the orientation of the polymerizable smectic liquid crystal compound is not disturbed when the polarizing film is formed. The azo dye (1) contained in the composition for forming a polarizing film may be one type or two or more types. When there are two or more azo dyes (1) contained in the composition for forming a polarizing film, the total amount may be in the above range.

<Polymerizable smectic liquid crystal compound>
The polymerizable smectic liquid crystal compound contained in the composition for forming a polarizing film is a compound having a polymerizable group and showing a liquid crystal state of a smectic phase. The polymerizable group means a group involved in the polymerization reaction of the polymerizable smectic liquid crystal compound.

The liquid crystal state exhibited by the polymerizable smectic liquid crystal compound is preferably a higher order smectic phase. The high-order smectic phase here means a smectic B phase, a smectic D phase, a smectic E phase, a smectic F phase, a smectic G phase, a smectic H phase, a smectic I phase, a smectic J phase, a smectic K phase, and a smectic L phase. Among them, a smectic B phase, a smectic F phase, and a smectic I phase are more preferable. The polarizing film having a high degree of orientational order can be obtained depending on the liquid crystal state exhibited by the polymerizable smectic liquid crystal compound. In addition, the polarizing film having such a high degree of orientational order can obtain a Bragg peak in X-ray diffraction measurement.
The Bragg peak is a peak derived from the surface periodic structure of molecular orientation, and according to the composition for forming a polarizing film, the polarizing film having a periodic interval of 3.0 to 5.0 mm can be obtained.

As a preferable polymerizable smectic liquid crystal compound, for example, a compound represented by the formula (2) (hereinafter sometimes referred to as “compound (2)”) may be mentioned.

^{U 1 -V 1 -W 1 -X 1} -Y 1 -X 2 -Y 2 -X 3 -W 2 -V 2 -U 2 (2)
[In Formula (2),
X ¹ , X ² and X ³ each independently represent a p-phenylene group which may have a substituent or a cyclohexane-1,4-diyl group which may have a substituent. However, at least one of X ¹ , X ² and X ³ is a p-phenylene group which may have a substituent.
Y ¹ and ^{Y 2,} independently of one _{another, -CH 2 CH 2 -, -} CH 2 O -, - COO -, - OCOO-, a single ^{bond, -N = N -, - CR} a = CR b -, - C≡C— or —CR ^a ═N— is represented. R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
U ¹ represents a hydrogen atom or a polymerizable group.
U ² represents a polymerizable group.
W ¹ and W ² each independently represent a single bond, —O—, —S—, —COO— or —OCOO—.
V ¹ and V ² each independently represent an optionally substituted alkanediyl group having 1 to 20 carbon atoms, and —CH ₂ — constituting the alkanediyl group is —O—, — S- or -NH- may be substituted. ]

It is preferable that at least ^{two of} X ¹ , X ² and X ³ are p-phenylene groups which may have a substituent.
The p-phenylene group is preferably unsubstituted. The cyclohexane-1,4-diyl group is preferably a trans-cyclohexane-1,4-diyl group, and the trans-cyclohexane-1,4-diyl group may also be unsubstituted. More preferred.

Examples of the substituent that the p-phenylene group or the cyclohexane-1,4-diyl group has include an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, and a butyl group; a cyano group; a halogen atom, and the like. . In addition, —CH ₂ — constituting the cyclohexane-1,4-diyl group may be replaced by —O—, —S— or —NR—. R is a C1-C6 alkyl group or a phenyl group.

Y ¹ is preferably —CH ₂ CH ₂ —, —COO— or a single bond, and Y ² is preferably —CH ₂ CH ₂ — or —CH ₂ O—.

U ² is a polymerizable group. U ¹ is a hydrogen atom or a polymerizable group, and preferably a polymerizable group. U ¹ and U ² are preferably both polymerizable groups. The polymerizable group is preferably a photopolymerizable group. The photopolymerizable group refers to a group that can participate in a polymerization reaction by an active radical or an acid generated from a photopolymerization initiator described later. The use of a polymerizable smectic liquid crystal compound having a photopolymerizable group is also advantageous in that the polymerizable smectic liquid crystal compound can be polymerized under a lower temperature condition.

The polymerizable groups of U ¹ and U ² may be different from each other, but are preferably the same type.
Examples of the polymerizable group include a vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group, and oxetanyl group. Among them, acryloyloxy group, methacryloyloxy group, vinyloxy group, oxiranyl group and oxetanyl group are preferable, and acryloyloxy group is more preferable.

Examples of the alkanediyl group of V ¹ and V ² include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,3-diyl group, a butane-1,4-diyl group, and a pentane-1,5. -Diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, decane-1,10-diyl group, tetradecane-1,14-diyl group and icosane And a -1,20-diyl group. V ¹ and V ² are preferably alkanediyl groups having 2 to 12 carbon atoms, and more preferably alkanediyl groups having 6 to 12 carbon atoms.
Examples of the substituent that the alkanediyl group has include a cyano group and a halogen atom. The alkanediyl group is preferably unsubstituted, and more preferably an unsubstituted and linear alkanediyl group.

W ¹ and W ² are independently of each other, preferably a single bond or —O—.

  Examples of the compound (2) include compounds represented by formulas (2-1) to (2-24). When a specific example of the compound (2) has a cyclohexane-1,4-diyl group, the cyclohexane-1,4-diyl group is preferably a trans isomer.

The polymerizable smectic liquid crystal compound can be used alone or in combination of two or more for the composition for forming a polarizing film.
When the polymerizable smectic liquid crystal compound is used in the composition for forming a polarizing film, the phase transition temperature of the polymerizable smectic liquid crystal compound is obtained in advance, and the polymerizable smectic liquid crystal compound is polymerized under a temperature condition lower than the phase transition temperature. The components other than the polymerizable smectic liquid crystal compound in the composition for forming a polarizing film are adjusted. Examples of the component capable of controlling the polymerization temperature include a polymerization initiator, a sensitizer and a polymerization inhibitor which will be described later. The polymerization temperature of the polymerizable smectic liquid crystal compound can be controlled by adjusting these types and amounts as appropriate. In the case where two or more kinds of polymerizable smectic liquid crystal compounds are used in the composition for forming a polarizing film, after obtaining the phase transition temperature of the mixture of the two or more kinds of polymerizable smectic liquid crystal compounds, Control the polymerization temperature.

Among the exemplified compounds (2), the formula (2-2), the formula (2-3), the formula (2-4), the formula (2-6), the formula (2-7), and the formula (2- 8) At least one selected from the group consisting of those represented by formula (2-13), formula (2-14), formula (2-15) and formula (2-24) is preferred.
The polymerizable smectic liquid crystal compound can be sufficiently mixed with each other or by interacting with the polymerization initiator used together under a temperature condition that easily falls below the phase transition temperature, that is, sufficiently high-order smectic phase liquid crystal state. A compound that can be polymerized while being held is preferred. More specifically, the polymerizable smectic liquid crystal compound sufficiently retained the liquid crystal state of the higher order smectic phase under the temperature condition of 70 ° C. or less, preferably 60 ° C. or less, due to the interaction with the polymerization initiator. A compound that can be polymerized as it is is preferred.

  The polymerizable smectic liquid crystal compound contained in the composition for forming a polarizing film may be a single type or a plurality of types, but is preferably a plurality of types.

  The content ratio of the polymerizable smectic liquid crystal compound in the polarizing film forming composition is preferably 70 to 99.9% by mass, and 90 to 99.9% by mass with respect to the solid content of the polarizing film forming composition. More preferred. When the content ratio of the polymerizable smectic liquid crystal compound is within the above range, the orientation of the polymerizable smectic liquid crystal compound tends to be high. Here, solid content means the total amount of the component remove | excluding volatile components, such as a solvent, from this polarizing film formation composition. In addition, when multiple types of polymerizable smectic liquid crystal compounds are contained in the composition for forming a polarizing film, the total content thereof may be in the above range.

<Solvent>
The composition for forming a polarizing film may contain a solvent. In general, since the viscosity of the polymerizable smectic liquid crystal compound is high, application is facilitated by including a solvent, and as a result, it is often easy to form a polarizing film. As the solvent, a solvent capable of completely dissolving the polymerizable smectic liquid crystal compound and the azo dye (1) is preferable. Moreover, it is preferable that it is an inert solvent with respect to the polymerization reaction of the composition for polarizing film formation.
Solvents include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether and propylene glycol monomethyl ether; ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone Or ester solvents such as propylene glycol methyl ether acetate and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; toluene And aromatic hydrocarbon solvents such as xylene, nitrile solvents such as acetonitrile; Hydrofuran and ether solvents such as dimethoxyethane; chlorine-containing solvents such as chloroform and chlorobenzene; and the like. These solvents may be used alone or in combination.

  As for content of a solvent, 50-98 mass% is preferable with respect to the total amount of the said composition for polarizing film formation. In other words, the solid content in the composition for forming a polarizing film is preferably 2 to 50% by mass. When the solid content is 2% by mass or more, a thin main polarizing film which is one of the objects of the present invention tends to be obtained more easily. On the other hand, when the solid content is 50% by mass or less, since the viscosity of the composition for forming a polarizing film is lowered, the thickness of the polarizing film tends to be substantially uniform, so that unevenness of the polarizing film is less likely to occur. There is. Moreover, this solid content can be determined so that the thickness of the polarizing film mentioned later can be formed.

<Polymerization reaction aid>
The composition for forming a polarizing film preferably contains a polymerization initiator. The polymerization initiator is a compound capable of initiating a polymerization reaction of a polymerizable smectic liquid crystal compound, and a photopolymerization initiator is preferable in that the polymerization reaction can be initiated under a lower temperature condition. Specifically, a compound capable of generating an active radical or an acid by the action of light is used as a photopolymerization initiator. Among the photopolymerization initiators, those that generate radicals by the action of light are more preferable.

  Examples of the polymerization initiator include benzoin compounds, benzophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, triazine compounds, iodonium salts, and sulfonium salts.

Hereinafter, specific examples of this polymerization initiator will be given.
Examples of the benzoin compound include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

  Examples of the benzophenone compound include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4′-methyldiphenyl sulfide, 3,3 ′, 4,4′-tetra (tert-butylperoxycarbonyl). ) Benzophenone and 2,4,6-trimethylbenzophenone.

  Examples of the alkylphenone compound include diethoxyacetophenone, 2-methyl-2-morpholino-1- (4-methylthiophenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl). ) Butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethane-1-one, 2-hydroxy-2-methyl-1 -[4- (2-hydroxyethoxy) phenyl] propan-1-one, 1-hydroxycyclohexyl phenyl ketone and 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propane-1- ON oligomers.

  Examples of the acylphosphine oxide compound include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide.

  Examples of the triazine compound include 2,4-bis (trichloromethyl) -6- (4-methoxyphenyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (4-methoxy Naphthyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (4-methoxystyryl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6 [2- (5-Methylfuran-2-yl) ethenyl] -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2- (furan-2-yl) ethenyl] -1 , 3,5-triazine, 2,4-bis (trichloromethyl) -6- [2- (4-diethylamino-2-methylphenyl) ethenyl] -1,3,5-triazine and 2,4-bis (trichloro Methyl)- - such as [2- (3,4-dimethoxyphenyl) ethenyl] -1,3,5-triazine.

  A polymerization initiator that can be easily obtained from the market can also be used. Commercially available polymerization initiators include “Irgacure 907”, “Irgacure 184”, “Irgacure 651”, “Irgacure 819”, “Irgacure 250”, “Irgacure 369” (Ciba Japan Co., Ltd.); “Sake All BZ”, “Sake All Z”, “Sake All BEE” (Seiko Chemical Co., Ltd.); “Kayacure BP100” (Nippon Kayaku Co., Ltd.); “Kayacure UVI-6992” (manufactured by Dow); "Adekaoptomer SP-152", "Adekaoptomer SP-170" (ADEKA); "TAZ-A", "TAZ-PP" (Nihon Shibel Hegner); and "TAZ-104" (Sanwa Chemical) Companies).

  When the polarizing film-forming composition contains a polymerization initiator, the content can be appropriately adjusted according to the type and amount of the polymerizable smectic liquid crystal compound contained in the polarizing film-forming composition, For example, the content of the polymerization initiator with respect to 100 parts by mass in total of the polymerizable smectic liquid crystal compound is preferably in the range of 0.1 to 30 parts by mass, more preferably in the range of 0.5 to 10 parts by mass, The range of 8 parts by mass is more preferable. If the content of the polymerizable initiator is within this range, the polymerizable smectic liquid crystal compound can be polymerized without disturbing the orientation of the polymerizable smectic liquid crystal compound, so that the polymerizable smectic liquid crystal compound exhibits a liquid crystal state of a higher order smectic phase. Polymerization can be carried out while being held.

  When the composition for forming a polarizing film contains a polymerization initiator, the composition for forming a polarizing film may contain a sensitizer. As the sensitizer, a photosensitizer is preferable. Examples of the sensitizer include xanthone compounds such as xanthone and thioxanthone (for example, 2,4-diethylthioxanthone and 2-isopropylthioxanthone); anthracene such as anthracene and an alkoxy group-containing anthracene (for example, dibutoxyanthracene). Compounds; phenothiazine, rubrene and the like.

  When the said composition for polarizing film formation contains a polymerization initiator and a sensitizer, the polymerization reaction of the polymerizable smectic liquid crystal compound contained in the said composition for polarizing film formation can be accelerated | stimulated more. The amount of the sensitizer used can be appropriately adjusted according to the type and amount of the polymerization initiator and the polymerizable smectic liquid crystal compound used together. For example, the amount used is 0 with respect to 100 parts by mass of the total amount of the polymerizable smectic liquid crystal compound. The range of 0.1-30 mass parts is preferable, the range of 0.5-10 mass parts is more preferable, and the range of 0.5-8 mass parts is further more preferable.

  It has been explained that the polymerization reaction of the polymerizable smectic liquid crystal compound can be promoted by adding a sensitizer to the composition for forming a polarizing film. In order to make the polymerization reaction proceed stably, the composition for forming a polarizing film is used. The composition can also contain a polymerization inhibitor appropriately. By containing the polymerization inhibitor, the degree of progress of the polymerization reaction of the polymerizable smectic liquid crystal compound can be controlled.

  Examples of the polymerization inhibitor include radicals such as hydroquinone, alkoxy group-containing hydroquinone, alkoxy group-containing catechol (eg, butyl catechol), pyrogallol, 2,2,6,6-tetramethyl-1-piperidinyloxy radical, and the like. Supplementary agents; thiophenols; β-naphthylamines and β-naphthols.

  When a polymerization inhibitor is contained in the polarizing film forming composition, the content can be appropriately adjusted according to the type and amount of the polymerizable smectic liquid crystal compound used, the amount of the sensitizer used, etc. The content of the polymerization inhibitor with respect to 100 parts by weight of the polymerizable smectic liquid crystal compound is preferably in the range of 0.1 to 30 parts by weight, more preferably in the range of 0.5 to 10 parts by weight, and 0.5 to 8 parts by weight. The range of is more preferable. If the content of the polymerization inhibitor is within this range, the polymerizable smectic liquid crystal compound can be polymerized without disturbing the orientation of the polymerizable smectic liquid crystal compound contained in the composition for forming a polarizing film. However, it is possible to carry out polymerization while maintaining the liquid crystal state of a higher-order smectic phase in good condition.

<Leveling agent>
The composition for forming a polarizing film preferably contains a leveling agent. The leveling agent has a function of adjusting the fluidity of the composition for forming a polarizing film, and making the coating film obtained by applying the composition for forming a polarizing film more flat, such as a surfactant. Can be mentioned. The leveling agent is more preferably at least one selected from the group consisting of a leveling agent having a polyacrylate compound as a main component and a leveling agent having a fluorine atom-containing compound as a main component.

  Leveling agents mainly composed of polyacrylate compounds include “BYK-350”, “BYK-352”, “BYK-353”, “BYK-354”, “BYK-355”, “BYK-358N”, “ BYK-361N ”,“ BYK-380 ”,“ BYK-381 ”,“ BYK-392 ”[BYK Chemie], and the like.

  Leveling agents mainly composed of fluorine atom-containing compounds include "Megafac R-08", "R-30", "R-90", "F-410", "F-411", "F-443", "F-445", "F-470", "F-471", "F-477", "F-479", "F-482" and the same "F-483" [DIC Corporation]; "Surflon S-381", "S-382", "S-383", "S-393", "SC-101", "SC" -105 "," KH-40 "and" SA-100 "[AGC Seimi Chemical Co., Ltd.];" E1830 "," E5844 "[Daikin Fine Chemical Laboratory Co., Ltd.];" F-top EF301 "," EF303 " ", EF351" and "EF352" [Mitsubishi Materials Child Kasei Co., Ltd.] and the like.

  When the leveling agent is contained in the polarizing film forming composition, the content thereof is preferably in the range of 0.3 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the polymerizable smectic liquid crystal compound. A range of not less than 3 parts by mass and more preferably not less than 3 parts by mass. When the content of the leveling agent is within the above range, it is easy to horizontally align the polymerizable smectic liquid crystal compound, and the resulting polarizing film tends to be smoother. When the content of the leveling agent with respect to the polymerizable smectic liquid crystal compound exceeds the above range, unevenness tends to occur in the obtained polarizing film. In addition, this polarizing film formation composition may contain 2 or more types of leveling agents.

<Formation method of this polarizing film>
Next, a method for forming the polarizing film from the polarizing film forming composition will be described. In such a method, it is preferable to form the polarizing film by applying the composition for forming a polarizing film on a substrate, preferably on a transparent substrate.

<Transparent substrate>
The said transparent base material is a base material which has the transparency which can permeate | transmit light, especially visible light. The transparency refers to a characteristic that the transmittance with respect to a light beam having a wavelength of 380 to 780 nm is 80% or more. Specific examples of such transparent substrates include glass substrates, plastic translucent sheets, and translucent films. Examples of the plastic constituting the translucent sheet or translucent film include polyolefins such as polyethylene, polypropylene and norbornene polymers; cyclic olefin resins; polyvinyl alcohol; polyethylene terephthalate; polymethacrylates; Acid esters; cellulose esters such as triacetyl cellulose, diacetyl cellulose and cellulose acetate propionate; polyethylene naphthalates; polycarbonates; polysulfones; polyether sulfones; polyether ketones; and plastics such as polyphenylene sulfide and polyphenylene oxide. Among the specific examples of the transparent substrate described above, a plastic light-transmitting film, that is, a polymer film is preferable in view of a preferable plastic light-transmitting sheet and light-transmitting film. Among the polymer films, a polymer film made of cellulose ester, cyclic olefin resin, polyethylene terephthalate or polymethacrylic acid ester is particularly preferable because it can be easily obtained from the market or has excellent transparency. Is preferred. In producing the polarizing film using such a transparent substrate, the transparent substrate can be easily handled without causing damage such as tearing when the transparent substrate is transported or stored. A support base material or the like may be pasted. Moreover, although mentioned later, when manufacturing a circularly-polarizing plate from this polarizing film, retardation may be provided to this transparent base material. In this case, a polymer film is prepared as a transparent substrate, and the polymer film is subjected to stretching treatment to impart retardation to the polymer film to obtain a retardation film. A conductive film may be used as a transparent substrate. The method for imparting retardation to the transparent substrate (polymer film) will be described later.

Among the polymer films, when phase difference is imparted, films made of cellulose ester or cyclic olefin resin (cellulose ester film, cyclic olefin resin film) are easy to control the retardation value. preferable. Hereinafter, these two types of polymer films will be described in detail.
The cellulose ester constituting the cellulose ester film is one in which at least a part of hydroxyl groups contained in cellulose is converted to acetate ester. A cellulose ester film comprising such a cellulose ester can be easily obtained from the market. Examples of commercially available triacetyl cellulose films include “Fujitac Film” (Fuji Photo Film Co., Ltd.); “KC8UX2M”, “KC8UY” and “KC4UY” (Konica Minolta Opto Co., Ltd.). Such a commercially available triacetyl cellulose film can be used as a transparent substrate as it is or after imparting retardation as necessary. In addition, the surface of the prepared transparent substrate can be used as the transparent substrate 1 after being subjected to surface treatment such as antiglare treatment, hard coat treatment, antistatic treatment or antireflection treatment.

  In order to impart retardation to the polymer film, as described above, the polymer film is stretched. Any polymer film made of plastic, that is, a thermoplastic resin can be stretched, but a cyclic olefin-based resin film is preferable in that the retardation can be easily controlled. The cyclic olefin resin constituting the cyclic olefin resin film is composed of, for example, a polymer or copolymer (cyclic olefin resin) of a cyclic olefin such as norbornene or a polycyclic norbornene monomer. The olefin resin may partially contain a ring opening. Moreover, what hydrogenated the cyclic olefin resin containing a ring opening part may be used. Further, the cyclic olefin resin is, for example, a copolymer of a cyclic olefin and a chain olefin or a vinylated aromatic compound (such as styrene) in that the transparency is not significantly impaired or the hygroscopicity is not significantly increased. It may be. The cyclic olefin resin may have a polar group introduced in its molecule.

  When the cyclic olefin resin is a copolymer of a cyclic olefin and an aromatic compound having a chain olefin or a vinyl group, the chain olefin is ethylene, propylene, or the like, and a vinylated aromatic Examples of the compound include styrene, α-methylstyrene, and alkyl-substituted styrene. In such a copolymer, the content ratio of the structural unit derived from the cyclic olefin is in the range of 50 mol% or less, for example, about 15 to 50 mol% with respect to all the structural units of the cyclic olefin resin. When the cyclic olefin-based resin is a terpolymer obtained from a cyclic olefin, a chain olefin, and a vinylated aromatic compound, for example, the content ratio of the structural unit derived from the chain olefin is the cyclic olefin. It is about 5-80 mol% with respect to all the structural units of a resin, and the content rate of the structural unit derived from a vinylated aromatic compound is about 5-80 mol%. Such a terpolymer cyclic olefin resin has the advantage that the amount of expensive cyclic olefin used can be relatively reduced when the cyclic olefin resin is produced.

  Cyclic olefin resins that can produce a cyclic olefin resin film are readily available from the market. Commercially available cyclic olefin-based resins include “Topas” [Ticona (Germany)]; “Arton” [JSR Corporation]; “ZEONOR” and “ZEONEX” [Nippon Zeon Corporation] “Apel” [Mitsui Chemicals, Inc.] and the like. Such a cyclic olefin-based resin can be formed into a film (cyclic olefin-based resin film) by, for example, known film forming means such as a solvent casting method or a melt extrusion method. Moreover, the cyclic olefin resin film already marketed with the form of a film can also be used. Examples of such commercially available cyclic olefin resin films include “Essina” and “SCA40” [Sekisui Chemical Co., Ltd.]; “Zeonor Film” [Optes Co., Ltd.]; “Arton Film” [JSR Co., Ltd.] ] Etc. are mentioned.

  Next, a method for imparting retardation to the polymer film will be briefly described. The polymer film can be provided with retardation by a known stretching method. For example, a roll (winding body) in which a polymer film is wound on a roll is prepared, the film is continuously unwound from the winding body, and the unwound film is conveyed to a heating furnace. The set temperature of the heating furnace is in the range of near the glass transition temperature (° C.) to [glass transition temperature +100] (° C.) of the polymer film, preferably near the glass transition temperature (° C.) to [glass transition temperature +50] (° C. ). In the heating furnace, when the film is stretched in the direction of travel or in the direction perpendicular to the direction of travel, the transport direction and tension are adjusted, and the film is uniaxially or biaxially stretched at an arbitrary angle. . The draw ratio is usually in the range of about 1.1 to 6 times, preferably in the range of about 1.1 to 3.5 times. In addition, the method of stretching in an oblique direction is not particularly limited as long as the orientation axis can be continuously inclined to a desired angle, and a known stretching method can be employed. Examples of such a stretching method include the methods described in JP-A-50-83482 and JP-A-2-113920.

When used as a transparent substrate, the thickness of the polymer film is preferably such that the weight is such that it can be handled practically and sufficient transparency can be ensured. Tends to be lowered and the processability tends to be inferior. Therefore, an appropriate thickness of these films is, for example, about 5 to 300 μm, preferably 20 to 200 μm. When this polarizing film is used as a circularly polarizing plate, which will be described later, since the display device using the circularly polarizing plate is assumed to be used for mobile purposes, the thickness of the film is particularly preferably about 20 to 100 μm.
In addition, when giving retardation to a film by extending | stretching, the thickness after extending | stretching is determined by the thickness of the film before extending | stretching, and a draw ratio.

<Alignment film>
An alignment film is preferably formed on the base material used for the production of the polarizing film. In that case, the composition for forming a polarizing film is applied onto the alignment film. For this reason, it is preferable that the alignment film has a solvent resistance that does not dissolve when the polarizing film-forming composition is applied. Moreover, it is preferable to have heat resistance in the heat treatment for removing the solvent and aligning the liquid crystal. As the alignment film, an alignment polymer can be used.

  Examples of the orientation polymer include polyamides and gelatins having an amide bond in the molecule, polyimides having an imide bond in the molecule, and polyamic acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyacrylamide which are hydrolysates thereof. Mention may be made of polymers such as oxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid or polyacrylic acid esters. Among these, polyvinyl alcohol is preferable. These alignment polymers forming the alignment film may be used alone or in combination of two or more.

The alignment polymer can be formed on the substrate by applying the alignment polymer on the substrate as an alignment polymer composition (solution containing the alignment polymer) dissolved in a solvent. The solvent used in the alignment polymer composition is not particularly limited, and specifically, water; alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether Ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate and ethyl lactate; ketones such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone and methyl isobutyl ketone Solvents; Aliphatic hydrocarbon solvents such as pentane, hexane and heptane; Aromatic hydrocarbon solvents such as toluene and xylene; Acetonitrile, etc. Nitrile solvents; tetrahydrofuran, and ether solvents such as dimethoxyethane; and the like; chlorinated hydrocarbon solvents such as chloroform and chlorobenzene. These organic solvents may be used alone or in combination of two or more.

  A commercially available alignment film material may be used as it is as the alignment polymer composition for forming the alignment film. Examples of commercially available alignment film materials include Sunever (registered trademark, manufactured by Nissan Chemical Industries, Ltd.) and Optmer (registered trademark, manufactured by JSR).

  As a method of forming an alignment film on the substrate, for example, the alignment polymer composition or a commercially available alignment film material is applied on the substrate, and then annealed to form the alignment film on the substrate. An alignment film can be formed. The thickness of the alignment film thus obtained is, for example, in the range of 10 nm to 10000 nm, and preferably in the range of 10 nm to 1000 nm.

  In order to impart an alignment regulating force to the alignment film, it is preferable to perform rubbing (rubbing method) as necessary. By imparting the alignment regulating force, the polymerizable smectic liquid crystal compound can be aligned in a desired direction.

  As a method of imparting alignment regulating force by the rubbing method, for example, a rubbing cloth is wound, a rotating rubbing roll is prepared, and a laminate in which an alignment film forming coating film is formed on a substrate is used as a stage. There is a method in which the alignment film-forming coating film and the rotating rubbing roll are brought into contact with each other by being placed and conveyed toward the rotating rubbing roll.

  A so-called photo-alignment film can also be used. The photo-alignment film forms a photo-alignment inducing layer, and may impart an alignment regulating force by irradiating polarized light (preferably, polarized UV). In forming the photo-alignment inducing layer, first, a composition containing a polymer or monomer having a photoreactive group and a solvent (hereinafter, sometimes referred to as “photo-alignment film forming composition”) is prepared. The photoreactive group refers to a group that generates liquid crystal alignment ability when irradiated with light (light irradiation). Specifically, it causes photoreactions that are the origin of liquid crystal alignment ability, such as molecular orientation induction or isomerization reaction, dimerization reaction, photocrosslinking reaction, or photolysis reaction caused by light irradiation. is there. Among the photoreactive groups, those utilizing a dimerization reaction or a photocrosslinking reaction are preferable because they are excellent in orientation and maintain a smectic liquid crystal state when a polarizing film is formed. As the photoreactive group capable of causing the above reaction, those having an unsaturated bond, particularly a double bond are preferable, and a carbon-carbon double bond (C═C bond), a carbon-nitrogen double bond (C = N bond), a group having at least one selected from the group consisting of a nitrogen-nitrogen double bond (N = N bond) and a carbon-oxygen double bond (C = O bond) is particularly preferable.

Examples of the photoreactive group having a C═C bond include a vinyl group, a polyene group, a stilbene group, a stilbazole group, a stilbazolium group, a chalcone group, and a cinnamoyl group. Examples of the photoreactive group having a C═N bond include groups having a structure such as an aromatic Schiff base and an aromatic hydrazone. Examples of the photoreactive group having an N = N bond include an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group and a formazan group, and those having a basic structure of azoxybenzene. Examples of the photoreactive group having a C═O bond include a benzophenone group, a coumarin group, an anthraquinone group, and a maleimide group. These groups may have a substituent such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group, and a halogenated alkyl group.
Among them, a photoreactive group capable of causing a photodimerization reaction is preferable, and a cinnamoyl group and a chalcone group have a relatively small amount of polarized light irradiation necessary for photoalignment, and a photoalignment film having excellent thermal stability and temporal stability. Since it is easy to obtain, it is preferable. Further, as the polymer having a photoreactive group, a polymer having a cinnamoyl group in which the terminal portion of the polymer side chain has a cinnamic acid structure is particularly preferable.

  A polymer or monomer having a photoreactive group is applied as a composition for forming a photo-alignment film dissolved in a solvent to form a photo-alignment-inducing layer (film) on the transparent substrate. Can do. The solvent used in the composition is not particularly limited, and solvents such as those used in the alignment polymer composition described above can be applied depending on the solubility of the polymer or monomer having a photoreactive group.

  The concentration of the polymer or monomer having a photoreactive group with respect to the composition for forming a photoalignment film can be appropriately adjusted depending on the type of the polymer or monomer having the photoreactive group and the thickness of the photoalignment film to be produced. Expressed in terms of solid content concentration, it is preferably at least 0.2 mass%, particularly preferably in the range of 0.3-10 mass%. Further, the composition for forming a photo-alignment film may contain a polymer material such as polyvinyl alcohol and polyimide, and a sensitizer, as long as the characteristics of the photo-alignment film are not significantly impaired.

  Examples of the method for applying the orientation polymer or the polymer or monomer having a photoreactive group on a transparent substrate include spin coating, extrusion, gravure coating, die coating, bar coating, and applicator method. A known method such as a coating method such as a flexographic method or the like is employed. In addition, when implementing this polarizing film manufacture by the continuous manufacturing method of the Roll to Roll format mentioned later, the printing methods, such as the gravure coating method, the die coating method, or a flexo method, are employ | adopted normally.

  Note that a plurality of regions (patterns) having different orientation directions can be formed by performing masking when performing rubbing or polarized light irradiation.

<Method for producing the polarizing film>
On the alignment film formed on the (transparent) substrate, the polarizing film forming composition of the present invention is applied to obtain a coating film. Examples of the method for applying the composition for forming a polarizing film on the alignment film (application method) include, for example, a method for applying an alignment polymer or a polymer (monomer) having a photoreactive group on a transparent substrate. The same method is mentioned.

  Next, a dry film is formed by drying and removing the solvent under the condition that the polymerizable smectic liquid crystal compound contained in the coating film is not polymerized. Examples of the drying method include a natural drying method, a ventilation drying method, a heat drying method, and a vacuum drying method. At this time, it is preferable that the liquid crystal state of the polymerizable smectic liquid crystal compound contained in the dry film is once changed to a nematic phase (nematic liquid crystal state), and then the nematic phase is transferred to the smectic phase. In order to form a smectic phase via the nematic phase in this way, for example, the polymerizable smectic liquid crystal compound contained in the dry film is heated to a temperature higher than the phase transition to the liquid crystal state of the nematic phase, and then the polymerizable A method is adopted in which the smectic liquid crystal compound is cooled to a temperature at which the smectic liquid crystal state is exhibited.

  When the polymerizable smectic liquid crystal compound in the dry film is in a smectic liquid crystal state, or when the polymerizable smectic liquid crystal compound is in a smectic liquid crystal state via a nematic liquid crystal state, the phase transition temperature of the polymerizable smectic liquid crystal compound to be used By measuring the above, the conditions (heating conditions) for controlling the liquid crystal state can be easily obtained. The measurement conditions for measuring the phase transition temperature will be described in the examples of the present application.

  When polymerizing the polymerizable smectic liquid crystal compound, a composition for forming a polarizing film comprising two or more polymerizable smectic liquid crystal compounds as the polymerizable smectic liquid crystal compound in order to maintain a liquid crystal state in a smectic phase satisfactorily. Is preferably used. When a polarizing film forming composition in which the content ratio of the two or more polymerizable smectic liquid crystal compounds is adjusted is used, a liquid crystal state of a smectic phase is formed via a nematic phase, and then a supercooled state is temporarily set. The liquid crystal state of a higher order smectic phase can be easily formed.

  Next, the polymerization process of the polymerizable smectic liquid crystal compound will be described. Here, the polarizing film-forming composition contains a photopolymerization initiator, and after the liquid crystal state of the polymerizable smectic liquid crystal compound in the dry film is changed to a smectic phase, the liquid crystal state of the smectic phase is maintained. A method for photopolymerizing the polymerizable smectic liquid crystal compound will be described in detail. In the photopolymerization, the light applied to the dry film includes the type of photopolymerization initiator contained in the dry film, or the type of polymerizable smectic liquid crystal compound (in particular, the type of photopolymerizable group possessed by the polymerizable smectic liquid crystal compound). ) And an amount of the active electron beam selected from the group consisting of visible light, ultraviolet light, and laser light. Among these, ultraviolet light is preferable in that it is easy to control the progress of the polymerization reaction and that apparatuses widely used in the field as photopolymerization apparatuses can be used. Therefore, it is preferable to select the type of the polymerizable smectic liquid crystal compound and the photopolymerization initiator contained in the polarizing film forming composition so that the photopolymerization can be performed with ultraviolet light. Moreover, when superposing | polymerizing, superposition | polymerization temperature can also be controlled by cooling a dry film with a suitable cooling means with ultraviolet light irradiation. By adopting such a cooling means, if the polymerizable smectic liquid crystal compound can be polymerized at a lower temperature, the polarizing film can be appropriately formed even if the above-mentioned transparent substrate has a relatively low heat resistance. There is also an advantage. In the photopolymerization, the patterned main polarizing film can be obtained by masking or developing.

  By performing photopolymerization as described above, the polymerizable smectic liquid crystal compound is polymerized while maintaining the liquid crystal state of a smectic phase, preferably a higher-order smectic phase as exemplified above, and this polarizing film is formed. Is done. This polarizing film obtained by polymerizing a polymerizable smectic liquid crystal compound while maintaining the liquid crystal state of the smectic phase is a conventional host-guest type polarizing film, that is, a nematic phase, due to the action of the azo dye (1). As compared with a polarizing film obtained by polymerizing a polymerizable nematic liquid crystal compound while maintaining the liquid crystal state, there is an advantage that polarization performance is much higher. Furthermore, there is an advantage that it is excellent in strength as compared with a case where only a dichroic dye or a lyotropic liquid crystal is applied.

  The thickness of the polarizing film thus formed is preferably in the range of 0.5 μm to 5 μm, more preferably 1 μm to 5 μm. Therefore, the thickness of the coating film for forming the present polarizing film is determined in consideration of the thickness of the obtained present polarizing film. In addition, the thickness of this polarizing film is calculated | required by the measurement of an interference film thickness meter, a laser microscope, or a stylus-type film thickness meter.

  Further, as described above, the polarizing film thus formed is particularly preferably one that can obtain a Bragg peak in X-ray diffraction measurement. As this polarizing film from which such a Bragg peak is obtained, for example, the present polarizing film showing a diffraction peak derived from a hexatic phase or a crystal phase can be mentioned.

In the production of the polarizing film described above, the polarizing film / (light) alignment film / transparent substrate is a member provided in this order. Such a member can be used as it is as a polarizer used in a liquid crystal display device. If the manufacturing method of the polarizer demonstrated so far is shown simply, this manufacturing method includes the following (1)-(5).
(1) A step of preparing a laminate including the alignment film on a transparent substrate;
(2) forming a film made of the composition for forming a polarizing film on the alignment film of the laminate;
(3) removing the solvent from the film;
(4) A step of bringing the polymerizable smectic liquid crystal compound contained in the film from which the solvent has been removed into a smectic liquid crystal state;
(5) A step of forming a polarizing film on the alignment film by polymerizing the polymerizable smectic liquid crystal compound while the polymerizable smectic liquid crystal compound maintains the smectic liquid crystal state.

<Continuous manufacturing method of this polarizing film>
As mentioned above, although the outline | summary of the manufacturing method of this polarizing film was demonstrated, when manufacturing this polarizing film commercially, the method which can manufacture this polarizing film continuously is calculated | required. Such a continuous manufacturing method is based on the Roll to Roll format, and is sometimes referred to as “the present manufacturing method”. In the present manufacturing method, the case where the substrate is a transparent substrate will be mainly described.

This manufacturing method is, for example,
Preparing a first roll in which a transparent substrate is wound around a first core;
Continuously feeding the transparent substrate from the first roll;
Applying a composition containing a polymer having a photoreactive group and a solvent, and continuously forming a first coating film on the transparent substrate;
A step of drying and removing the solvent from the first coating film to form a first dry film on the transparent substrate to obtain a first laminate continuously;
Irradiating the first dry film with polarized UV to form a photo-alignment film and continuously obtaining a second laminate;
Applying a composition containing a polymerizable smectic liquid crystal compound, a dichroic dye and a solvent on the photo-alignment film, and continuously forming a second coating film on the photo-alignment film; The coating film is dried under a condition in which the polymerizable smectic liquid crystal compound contained in the second coating film is not polymerized to form a second dry film on the photo-alignment film, thereby continuously forming the third laminate. A process of obtaining
After making the polymerizable smectic liquid crystal compound contained in the second dry film into a smectic liquid crystal state, the polarizing film is continuously formed by polymerizing the polymerizable smectic liquid crystal compound while maintaining the smectic liquid crystal state. Obtaining a step;
A step of winding the continuously obtained polarizing film around a second core to obtain a second roll. Here, with reference to FIG. 1, the principal part of this manufacturing method is demonstrated.

  The first roll 210 in which the transparent base material is wound around the first core 210A can be easily obtained from the market, for example. As a transparent base material which can be obtained from the market in the form of such a roll, the film etc. which consist of a cellulose ester, cyclic olefin resin, a polyethylene terephthalate, or a polymethacrylic acid ester are mentioned among the transparent base materials already illustrated. In addition, when the polarizing film is used as a circularly polarizing plate, a transparent substrate previously imparted with retardation is easily available from the market, for example, a retardation film made of a cellulose ester or a cyclic olefin resin. It is done.

  Subsequently, the transparent substrate is unwound from the first roll 210. The method for unwinding the transparent substrate is performed by installing an appropriate rotating means on the core 210A of the first roll 210 and rotating the first roll 210 by the rotating means. Alternatively, a suitable auxiliary roll 300 may be installed in the direction of transporting the transparent base material from the first roll 210 and the transparent base material may be unwound by the rotating means of the auxiliary roll 300. Further, the first winding core 210A and the auxiliary roll 300 may be provided with a rotating means so that the transparent substrate is unwound while applying an appropriate tension to the transparent substrate.

  When the transparent base material unwound from the first roll 210 passes through the coating device 211A, the composition for forming a photo-alignment film is applied onto the surface of the transparent base material by the coating device 211A. As described above, the coating apparatus 211A is a printing method such as a gravure coating method, a die coating method, or a flexo method in order to continuously apply the composition for forming a photo-alignment film in this way.

  The film that has passed through the coating apparatus 211A corresponds to a laminate of the above-described transparent substrate and the first coating film. Thus, the transparent base material on which the first coating film is formed (laminated) is conveyed to the drying furnace 212A and heated by the drying furnace 212A to the first laminated body including the transparent base material and the first dry film. And convert. For example, a hot air drying furnace or the like is used as the drying furnace 212A. The set temperature of the drying furnace 212A is determined according to the type of solvent contained in the composition for forming a photo-alignment film applied by the coating apparatus 211A. The drying furnace 212A may be divided into appropriate zones, and the set temperature may be different for each of the divided zones. A plurality of drying furnaces are arranged in series, and each drying is performed at different set temperatures. The film may be transported sequentially through the plurality of drying furnaces while operating the furnace.

  The first laminate continuously formed by passing through the heating furnace 212A is subsequently polarized on the surface of the laminate on the first dry film side or the transparent substrate side by the polarized UV irradiation device 213A. When UV is irradiated, the first dry film is converted into a light polarizing film. At that time, an angle formed by the film conveyance direction D1 and the alignment direction D2 of the formed photo-alignment film is set to about 45 °. FIG. 5 is a diagram schematically showing the relationship between the orientation direction D2 of the photo-alignment film formed after irradiation with polarized UV light and the film transport direction D1. That is, FIG. 1 shows that when the surface of the first laminate after passing through the polarized UV irradiation device 213A is viewed in the film transport direction D1 and the alignment direction D2 of the photo-alignment film, the angle formed by them is approximately 45 °. Indicates that

  Thus, after the 1st laminated body formed continuously passes the coating device 211B and the composition for polarizing film formation is apply | coated on the photo-alignment film of this 1st laminated body, drying furnace 212B The polymerizable smectic liquid crystal compound contained in the second laminate or the second dry film of the second laminate becomes a laminate in which a smectic liquid crystal state is formed. The drying furnace 212B has a role of drying and removing the solvent from the polarizing film forming composition applied on the photo-alignment film, and the polymerizable smectic liquid crystal compound contained in the second dry film is in a smectic phase liquid crystal state. As such, it plays a role of giving thermal energy to the second dry film. In addition, as described above, in order to make the polymerizable smectic liquid crystal compound into a smectic phase liquid crystal state, in order to make the polymerizable smectic liquid crystal compound into a nematic phase liquid crystal state, It is necessary to perform multi-stage heat treatment on the first laminated body under different heating conditions. Therefore, as described in the drying furnace 212A, the drying furnace 212B is composed of a plurality of zones having different set temperatures or a plurality of drying furnaces having different set temperatures, and the plurality of drying furnaces are connected in series. It is preferable to be in the form of installation.

  The film that has passed through the drying oven 212B is sufficiently irradiated with light while the solvent contained in the composition for forming a polarizing film is sufficiently removed and the polymerizable smectic liquid crystal compound in the second dry film maintains the liquid crystal state of the smectic phase. It is conveyed to the device 213B. By the light irradiation by the light irradiation device 213B, the polymerizable smectic liquid crystal compound is photopolymerized while maintaining the liquid crystal state, and the polarizing film is continuously formed on the alignment film.

  The polarizing film thus continuously formed is wound around the second core 220A in the form of a laminate including the transparent base material and the alignment film, and the form of the second roll 220 is obtained. When the formed polarizing film is wound up to obtain the second roll, winding using an appropriate spacer may be performed.

  In this way, the transparent base material passes through the first roll / coating device 211A / drying furnace 212A / polarized UV irradiation device 213A / coating device 211B / drying furnace 212B / light irradiation device 213B in this order. This polarizing film is continuously manufactured on the upper photo-alignment film.

  In addition, in the present manufacturing method shown in FIG. 1, a method of continuously manufacturing from the transparent base material to the present polarizing film is shown. For example, the transparent base material is a first roll / coating device 211A / drying furnace 212A / By passing the polarized UV irradiation device 213A in this order, the first laminated body formed continuously is wound around the core, and the first laminated body is manufactured in the form of a roll, and the first laminated body is produced from the roll. The polarizing film may be manufactured by passing the unwound first laminated body through the coating device 211B / drying furnace 212B / light irradiation device 213B in this order.

  The polarizing film obtained by this manufacturing method has a film shape and a long shape. When this polarizing film is used for a liquid crystal display device to be described later, the polarizing film is cut into a desired size according to the scale of the liquid crystal display device.

  As mentioned above, the configuration and the manufacturing method of the polarizing film have been described focusing on the case of the laminate of transparent substrate / photo-alignment film / main polarizing film. The photo-alignment film and the transparent substrate may be peeled from the body, or a layer or film other than the transparent substrate / photo-alignment film / main polarizing film may be laminated on the laminate. As these layers and films, as described above, the polarizing film may further include a retardation film, or may further include an antireflection layer or a brightness enhancement film.

  Moreover, it can also be set as the circularly-polarizing plate or elliptical polarizing plate of the form of retardation film / photo-alignment film | membrane / this polarizing film by making transparent base material itself into retardation film. For example, when a uniaxially stretched quarter-wave plate is used as the retardation film, by setting the irradiation direction of polarized UV to be approximately 45 ° with respect to the transport direction of the transparent substrate, Roll-to It is possible to produce a circularly polarizing plate with -Roll. Thus, it is preferable that the quarter wavelength plate used when manufacturing the circularly polarizing plate has a characteristic that the in-plane retardation value with respect to visible light becomes smaller as the wavelength becomes shorter.

  Further, using a half-wave plate as a retardation film, a linear polarizing plate roll was prepared in which the angle between the slow axis and the absorption axis of the polarizing film was shifted, and the surface on which the polarizing film was formed; It is possible to form a broadband circularly polarizing plate by further forming a quarter wavelength plate on the opposite side.

<Application of this polarizing film>
This polarizing film can be used for various display devices. A display device is a device having a display element and includes a light-emitting element or a light-emitting device as a light-emitting source. Examples of the display device include a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, an electron emission display device (for example, a field emission display device (FED), a surface field emission display device (SED). )), Electronic paper (display device using electronic ink or electrophoretic element, plasma display device, projection display device (eg, display device having a grating light valve (GLV) display device, digital micromirror device (DMD)), and Examples of the liquid crystal display device include a transmissive liquid crystal display device, a transflective liquid crystal display device, a reflective liquid crystal display device, a direct view liquid crystal display device, and a projection liquid crystal display device. These display devices may be display devices that display a two-dimensional image. And it may be a stereoscopic display apparatus for displaying a three-dimensional image.
This polarizing film can be effectively used particularly for a display device of an organic electroluminescence (EL) display device or an inorganic electroluminescence (EL) display device.

2 and 5 are schematic views schematically showing a cross-sectional configuration of a liquid crystal display device (hereinafter, sometimes referred to as “the present liquid crystal display device”) 10 using the present polarizing film. The liquid crystal layer 17 is sandwiched between two substrates 14a and 14b.
8 and 10 are schematic views schematically showing a cross-sectional configuration of an EL display device using the present polarizing film (hereinafter sometimes referred to as “the present EL display device”).
FIG. 11 is a schematic diagram schematically showing a configuration of a projection type liquid crystal display device using the polarizing film.

First, the liquid crystal display device 10 shown in FIG. 2 will be described.
A color filter 15 is disposed on the liquid crystal layer 17 side of the substrate 14a. The color filter 15 is disposed at a position facing the pixel electrode 22 across the liquid crystal layer 17, and the black matrix 20 is disposed at a position facing the boundary between the pixel electrodes. The transparent electrode 16 is disposed on the liquid crystal layer 17 side so as to cover the color filter 15 and the black matrix 20.
An overcoat layer (not shown) may be provided between the color filter 15 and the transparent electrode 16.

  Thin film transistors 21 and pixel electrodes 22 are regularly arranged on the liquid crystal layer 17 side of the substrate 14b. The pixel electrode 22 is disposed at a position facing the color filter 15 with the liquid crystal layer 17 interposed therebetween. An interlayer insulating film 18 having a connection hole (not shown) is disposed between the thin film transistor 21 and the pixel electrode 22.

A glass substrate and a plastic substrate are used as the substrate 14a and the substrate 14b.
As the glass substrate and the plastic substrate, those made of the same material as those exemplified as the transparent base material used in the production of the polarizing film can be adopted. Moreover, the transparent substrate 1 of this polarizing film may serve as both the substrate 14a and the substrate 14b. When manufacturing the color filter 15 and the thin film transistor 21 formed on the substrate, a glass substrate or a quartz substrate is preferable when a process of heating to a high temperature is required.

  As the thin film transistor, an optimum one can be adopted according to the material of the substrate 14b. Examples of the thin film transistor 21 include a high-temperature polysilicon transistor formed on a quartz substrate, a low-temperature polysilicon transistor formed on a glass substrate, and an amorphous silicon transistor formed on a glass substrate or a plastic substrate. In order to reduce the size of the present liquid crystal display device, a driver IC may be formed on the substrate 14b.

  A liquid crystal layer 17 is disposed between the transparent electrode 16 and the pixel electrode 22. In the liquid crystal layer 17, spacers 23 are arranged in order to keep the distance between the substrate 14a and the substrate 14b constant. In FIG. 2, columnar spacers are illustrated, but the spacers are not limited to columnar shapes, and the shape is arbitrary as long as the distance between the substrate 14 a and the substrate 14 b can be kept constant.

  Of the layers formed on the substrate 14a and the substrate 14b, an alignment film for aligning the liquid crystal in a desired direction may be disposed on the surface in contact with the liquid crystal layer 17. In addition, this polarizing film can be arrange | positioned inside a liquid crystal cell, ie, this polarizing film can also be arrange | positioned in the surface side which touches the liquid crystal layer 17. FIG. Hereinafter, such a format is referred to as an “in-cell format”. Details of the in-cell format will be described later.

  Each member is laminated in the order of the substrate 14a, the color filter 15 and the black matrix 20, the transparent electrode 16, the liquid crystal layer 17, the pixel electrode 22, the interlayer insulating film 18 and the thin film transistor 21, and the substrate 14b.

Among the substrates 14a and 14b sandwiching the liquid crystal layer 17, the polarizers 12a and 12b are provided outside the substrate 14b. Among these, at least one polarizer has the polarizing film. include.
Furthermore, it is preferable that retardation layers (for example, quarter-wave plates and optical compensation films) 13a and 13b are laminated. By disposing the present polarizing film on the polarizer 12b out of the polarizers 12a and 12b, the liquid crystal display device 10 can be provided with a function of converting incident light into linearly polarized light. The retardation films 13a and 13b may not be arranged depending on the structure of the liquid crystal display device and the type of liquid crystal compound contained in the liquid crystal layer 17, and the transparent substrate is a retardation film. When the circularly polarizing plate containing is used, the retardation film can be used as a retardation layer, so that the retardation layers 13a and / or 13b in FIG. 2 can be omitted. A polarizing film may be further provided on the light exit side (outside) of the polarizer including the polarizing film.
Further, an antireflection film for preventing reflection of external light may be disposed outside the polarizer including the polarizing film (on the outside of the polarizing film when a polarizing film is further provided).

  As described above, the polarizing film can be used for the polarizer 12a or 12b of the liquid crystal display device 10 of FIG. By providing the polarizing film on the polarizers 12a and / or 12b, the liquid crystal display device 10 can be thinned.

  When this polarizing film is used for the polarizer 12a or 12b, the stacking order is not particularly limited. This will be described with reference to an enlarged view of portions A and B surrounded by a dotted line in FIG.

  FIG. 3 is an enlarged schematic cross-sectional view of a portion A in FIG. 3A1 is provided such that when the polarizer 100 is used as the polarizer 12a, the polarizing film 3, the photo-alignment film 2, and the transparent substrate 1 are arranged in this order from the phase difference layer 13a side. Indicates that Moreover, (A2) of FIG. 3 shows that the transparent base material 1, the photo-alignment film 2, and the present polarizing film 3 are provided in this order from the retardation layer 13a side.

  FIG. 4 is an enlarged schematic view of a portion B in FIG. 4B1 is provided such that when the polarizer 100 is used as the polarizer 12b, the transparent substrate 1, the photo-alignment film 2, and the polarizing film 3 are arranged in this order from the retardation film 13b side. . 4B2 is provided such that when the polarizer 100 is used as the polarizer 12b, the polarizing film 3, the photo-alignment film 2, and the transparent substrate 1 are arranged in this order from the retardation film 13b side. .

A backlight unit 19 serving as a light source is disposed outside the polarizer 12b.
The backlight unit 19 includes a light source, a light guide, a reflection plate, a diffusion sheet, and a viewing angle adjustment sheet. Examples of the light source include electroluminescence, a cold cathode tube, a hot cathode tube, a light emitting diode (LED), a laser light source, and a mercury lamp. In addition, the type of the polarizing film can be selected in accordance with the characteristics of such a light source.

  When the liquid crystal display device 10 is a transmissive liquid crystal display device, white light emitted from a light source in the backlight unit 19 is incident on the light guide, changed in path by a reflector, and diffused by a diffusion sheet. Yes. The diffused light is adjusted to have a desired directivity by the viewing angle adjusting sheet, and then enters the polarizer 12b from the backlight unit 19.

  Of the incident light that is non-polarized light, only one linearly polarized light passes through the polarizer 12b of the liquid crystal panel. This linearly polarized light is converted into circularly polarized light or elliptically polarized light by the retardation layer 13b, and sequentially passes through the substrate 14b, the pixel electrode 22 and the like to reach the liquid crystal layer 17.

  Here, depending on the presence or absence of a potential difference between the pixel electrode 22 and the transparent electrode 16 facing the pixel electrode 22, the alignment state of the liquid crystal molecules contained in the liquid crystal layer 17 changes, and the luminance of light emitted from the liquid crystal display device 10 is controlled. Is done. When the liquid crystal layer 17 is in an alignment state in which the polarized light is transmitted as it is, the polarized light is transmitted through the liquid crystal layer 17 and the transparent electrode 16, and light in a specific wavelength range is transmitted through the color filter 15 and reaches the polarizer 12a. Therefore, the liquid crystal display device displays the color determined by the color filter brightest.

  On the contrary, when the liquid crystal layer 17 is in an alignment state in which the polarized light is converted and transmitted, the light transmitted through the liquid crystal layer 17, the transparent electrode 16, and the color filter 15 is absorbed by the polarizer 12a. As a result, this pixel displays black. In the intermediate alignment state between these two states, the luminance of light emitted from the liquid crystal display device 10 is also intermediate between the two, so that this pixel displays an intermediate color.

  In the case where the present liquid crystal display device 10 is a transflective liquid crystal display device, it is preferable to use a polarizing plate in which a quarter wavelength plate is further laminated (circularly polarizing plate). At this time, the pixel electrode 22 has a transmissive portion formed of a transparent material and a reflective portion formed of a material that reflects light. In the transmissive portion, an image is displayed in the same manner as in the transmissive liquid crystal display device described above. Is displayed. On the other hand, in the reflection portion, external light is incident on the liquid crystal display device, and circularly polarized light that has passed through the polarizing film passes through the liquid crystal layer 17 by the action of the quarter wave plate further provided in the polarizing film, and the pixel electrode. 22 is reflected and used for display.

Next, a suitable in-cell type liquid crystal display device (the present liquid crystal display device 24) using the present polarizing film will be described with reference to FIG.
In the present liquid crystal display device 24, the substrate 14a, the polarizer 12a, the retardation film 13a, the color filter 15 and the black matrix 20, the transparent electrode 16, the liquid crystal layer 17, the pixel electrode 22, the interlayer insulating film 18 and the thin film transistor 21, and the retardation film. 13b, the polarizer 12b, the substrate 14b, and the backlight unit 19 are laminated in this order. In this configuration, the polarizing film is preferably used as the polarizer 12a. In this configuration, the present polarizing film may be arranged in the order of the transparent base material 1, the photo-alignment film 2 and the main polarizing film 3 so that the transparent base material in the polarizer also serves as the substrate 14a. In the present liquid crystal display device 24 provided with the present polarizing film in such a configuration, a function of making incident light linearly polarized light is given. Similar to the liquid crystal display device 10, the retardation layers 13 a and 13 b may not be arranged depending on the type of liquid crystal compound included in the liquid crystal layer 17.

  Next, the EL display device 30 using the polarizing film will be described with reference to FIG. When the present polarizing film is used in the present EL display device, it is preferable to use the present polarizing film after making it into a circularly polarizing plate (hereinafter sometimes referred to as “this circularly polarizing plate”). There are two embodiments of this circularly polarizing plate. Therefore, before describing the configuration of the EL display device 30 and the like, two embodiments of the circularly polarizing plate will be described with reference to FIG.

  FIG. 6A is a cross-sectional view schematically showing the first embodiment of the circularly polarizing plate 110. The first embodiment is a circular polarizing plate 110 in which a retardation layer (retardation film) 4 is further provided on the polarizing film 3 in the polarizer 100. FIG. 6B is a cross-sectional view schematically showing a second embodiment of the circularly polarizing plate 110. This 2nd Embodiment uses a transparent base material 1 (retardation film 4) to which phase contrast is given beforehand as a transparent base material 1 used when manufacturing polarizer 100, so that a transparent base material is used. 1 is the circularly polarizing plate 110 having the function of the retardation layer 4 itself.

  Here, a manufacturing method of the present circularly polarizing plate 110 will be described. As described above, the second embodiment of the circularly polarizing plate 110 uses the transparent substrate 1 that has been previously provided with retardation as the transparent substrate 1, that is, the retardation film, in the manufacturing method for manufacturing the polarizing film 100. It can be manufactured by using. 1st Embodiment of the circularly-polarizing plate 110 should just form the retardation layer 4 by bonding a retardation film on this polarizing film 3 manufactured by this manufacturing method. When the polarizing film 100 is manufactured in the form of the second roll 220 by the manufacturing method, the polarizing film 100 is unwound from the second roll 220, cut into a predetermined size, and then cut. Although the form which bonds a retardation film to this polarizing film 100 may be sufficient, the book whose shape is a film form and an elongate shape by preparing the 3rd roll by which the retardation film is wound up by the core. The circularly polarizing plate 110 can also be manufactured continuously.

A method for continuously manufacturing the first embodiment of the circularly polarizing plate 110 will be described with reference to FIG. Such a manufacturing method is:
A step of continuously unwinding the polarizing film 100 from the second roll 220 and unwinding the retardation film continuously from a third roll 230 on which the retardation film is wound;
The circularly polarizing plate 110 is formed by continuously laminating the polarizing film provided on the polarizing film 100 unwound from the second roll 220 and the retardation film unwound from the third roll. Forming, and
The present circular polarizing plate 110 thus formed is wound around the fourth core 240A to obtain the fourth roll 240.

Preferred embodiments of this circularly polarizing plate include the following <X1> and <X2>.
<X1> The present polarizing film having the present polarizing film and a λ / 4 layer and satisfying the following requirements (A1) and (A2) (A1) The absorption axis of the present polarizing film, and the λ / 4 layer The angle with the slow axis of is approximately 45 °;
(A2) The value of the front retardation of the λ / 4 layer measured with light having a wavelength of 550 nm is in the range of 100 to 150 nm. <X2> The polarizing film, the λ / 2 layer, and the λ / 4 layer In this order, the circularly polarizing plate (B1) that satisfies all the following requirements (B1) to (B4) (B1) The angle formed between the absorption axis of the polarizing film and the slow axis of the λ / 2 layer is: Approximately 15 °;
(B2) The angle formed between the slow axis of the λ / 2 layer and the slow axis of the λ / 4 layer is approximately 60 °;
(B3) The value of the front retardation of the λ / 4 layer measured with light having a wavelength of 550 nm is in the range of 200 to 300 nm.
(B4) The λ / 4 layer is measured with light having a wavelength of 550 nm, and the value of the front retardation of the λ / 4 layer is in the range of 100 to 150 nm.

  As mentioned above, although the manufacturing method of 1st Embodiment of this circularly-polarizing plate 110 was demonstrated, when bonding this polarizing film 3 in the polarizer 100 and retardation film, using an appropriate adhesive, The polarizing film 3 and the retardation film may be bonded via an adhesive layer formed from the adhesive.

Next, the EL display device including the circular polarizing plate 110 will be described with reference to FIG.
In the EL display device 30, an organic functional layer 36 that is a light source and a cathode electrode 37 are laminated on a substrate 33 on which a pixel electrode 35 is formed. A circularly polarizing plate 31 is disposed on the opposite side of the organic functional layer 36 across the substrate 33, and the circularly polarizing plate 110 is used as the circularly polarizing plate 31. By applying a positive voltage to the pixel electrode 35 and a negative voltage to the cathode electrode 37 and applying a direct current between the pixel electrode 35 and the cathode electrode 37, the organic functional layer 36 emits light. The organic functional layer 36 that is a light emitting source includes an electron transport layer, a light emitting layer, a hole transport layer, and the like. The light emitted from the organic functional layer 36 passes through the pixel electrode 35, the interlayer insulating film 34, the substrate 33, and the circularly polarizing plate 31 (this circularly polarizing plate 110). Although the organic EL display device having the organic functional layer 36 will be described, the present invention may be applied to an inorganic EL display device having an inorganic functional layer.

  In order to manufacture the EL display device 30, first, the thin film transistor 40 is formed in a desired shape on the substrate 33. Then, an interlayer insulating film 34 is formed, and then a pixel electrode 35 is formed by sputtering and patterned. Thereafter, the organic functional layer 36 is laminated.

  Next, the circularly polarizing plate 31 (the present circularly polarizing plate 110) is provided on the surface of the substrate 33 opposite to the surface on which the thin film transistor 40 is provided.

  When this circularly polarizing plate 110 is used as the circularly polarizing plate 31, the stacking order will be described with reference to an enlarged view of a portion C surrounded by a dotted line in FIG. When the circular polarizing plate 110 is used as the circular polarizing plate 31, the retardation layer 4 in the circular polarizing plate 110 is disposed on the substrate 33 side. (C1) in FIG. 9 is an enlarged view in which the first embodiment of the circularly polarizing plate 110 is used as the circularly polarizing plate 31, and (C2) in FIG. 9 shows the second embodiment of the circularly polarizing plate 110. 3 is an enlarged view used as a circularly polarizing plate 31. FIG.

  Next, members other than the main polarizing film 31 (circular polarizing plate 110) of the EL display device 30 will be briefly described.

Examples of the substrate 33 include a sapphire glass substrate, a quartz glass substrate, a soda glass substrate and a ceramic substrate such as alumina; a metal substrate such as copper; a plastic substrate.
Although not shown, a heat conductive film may be formed on the substrate 33. Examples of the thermally conductive film include a diamond thin film (DLC or the like). When the pixel electrode 35 is a reflection type, light is emitted in the opposite direction to the substrate 33. Therefore, not only a transparent material but also a non-permeable material such as stainless steel can be used. A single substrate may be formed, or a plurality of substrates may be bonded together with an adhesive to form a laminated substrate. Further, these substrates are not limited to plate-like ones, and may be films.

  For example, a polycrystalline silicon transistor may be used as the thin film transistor 40. The thin film transistor 40 is provided at the end of the pixel electrode 35 and has a size of about 10 to 30 μm. The size of the pixel electrode 35 is about 20 μm × 20 μm to 300 μm × 300 μm.

  On the substrate 33, wiring electrodes of the thin film transistor 40 are provided. The wiring electrode has a low resistance and has a function of suppressing resistance by being electrically connected to the pixel electrode 35. In general, the wiring electrode includes Al, Al and transition metals (except for Ti), Ti or Those containing any one or more of titanium nitride (TiN) are used.

An interlayer insulating film 34 is provided between the thin film transistor 40 and the pixel electrode 35. The interlayer insulating film 34 is formed by sputtering or vacuum deposition of an inorganic material such as silicon oxide such as SiO ₂ or silicon nitride, a silicon oxide layer formed by SOG (spin-on-glass), a photoresist, a polyimide. In addition, any film may be used as long as it has insulating properties, such as a coating film of a resin material such as an acrylic resin.

  A rib 41 is formed on the interlayer insulating film 34. The rib 41 is disposed in the peripheral portion (between adjacent pixels) of the pixel electrode 35. Examples of the material of the rib 41 include acrylic resin and polyimide resin. The thickness of the rib 41 is preferably 1.0 μm or more and 3.5 μm or less, and more preferably 1.5 μm or more and 2.5 μm or less.

  Next, an EL element including a pixel electrode 35 that is a transparent electrode, an organic functional layer 36 that is a light emission source, and a cathode electrode 37 will be described. Each of the organic functional layers 36 includes at least one hole transport layer and a light emitting layer, and sequentially includes, for example, an electron injection transport layer, a light emitting layer, a hole transport layer, and a hole injection layer.

Examples of the pixel electrode 35 include ITO (tin-doped indium oxide), IZO (zinc-doped indium oxide), IGZO, ZnO, SnO _2, and In ₂ O _3, and ITO and IZO are particularly preferable. The pixel electrode 35 only needs to have a certain thickness or more that can sufficiently inject holes, and is preferably about 10 to 500 nm.
The pixel electrode 35 can be formed by an evaporation method (preferably a sputtering method). The sputtering gas is not particularly limited, and an inert gas such as Ar, He, Ne, Kr and Xe, or a mixed gas thereof may be used.

As a constituent material of the cathode electrode 37, for example, metal elements such as K, Li, Na, Mg, La, Ce, Ca, Sr, Ba, Al, Ag, In, Sn, Zn, and Zr may be used. In order to improve the operational stability of the electrode, it is preferable to use a two-component or three-component alloy system selected from the exemplified metal elements. Examples of the alloy system include Ag · Mg (Ag: 1 to 20 at%), Al·Li (Li: 0.3 to 14 at%), In · Mg (Mg: 50 to 80 at%), and Al · Ca (Ca: 5 to 20 at%) is preferable.
The cathode electrode 37 is formed by vapor deposition or sputtering. The thickness of the cathode electrode 37 is 0.1 nm or more, preferably 1 to 500 nm or more.

The hole injection layer has a function of facilitating the injection of holes from the pixel electrode 35, and the hole transport layer has a function of transporting holes and a function of blocking electrons. Also called transport layer.
The thickness of the light-emitting layer, the combined thickness of the hole injection layer and the hole transport layer, and the thickness of the electron injection / transport layer are not particularly limited and may vary depending on the formation method, but should be about 5 to 100 nm. Is preferred. Various organic compounds can be used for the hole injection layer and the hole transport layer. For the formation of the hole injecting and transporting layer, the light emitting layer and the electron injecting and transporting layer, a vacuum deposition method can be used in that a homogeneous thin film can be formed.

  Examples of the organic functional layer 36 that is a light emission source include those that use light emission (fluorescence) from singlet excitons, those that use light emission (phosphorescence) from triplet excitons, and those from singlet excitons. Including those using luminescence (fluorescence) and those using triplet excitons (phosphorescence), those formed with organic matter, those formed with organic matter and those formed with inorganic matter , A high molecular material, a low molecular material, a high molecular material and a low molecular material, and the like can be used. However, the present invention is not limited thereto, and an organic functional layer 36 using various known materials for EL elements can be used for the EL display device 30.

  A desiccant 38 is disposed in the space between the cathode electrode 37 and the sealing lid 39. This is because the organic functional layer 36 is vulnerable to humidity. Moisture is absorbed by the desiccant 38 to prevent the organic functional layer 36 from deteriorating.

FIG. 10 is a schematic diagram showing a cross-sectional configuration of another aspect of the EL display device 30. This EL display device 30 has a sealing structure using a thin film sealing film 41, and can obtain emitted light from the opposite surface of the array substrate.
As the thin film sealing film 41, it is preferable to use a DLC film obtained by evaporating DLC (diamond-like carbon) on an electrolytic capacitor film. The DLC film has a characteristic that moisture permeability is extremely poor, and has high moisture-proof performance. Further, a DLC film or the like may be directly deposited on the surface of the cathode electrode 37. Further, the thin film sealing film 41 may be formed by laminating a resin thin film and a metal thin film in multiple layers.

  As described above, the novel polarizing film (the present polarizing film) according to the present invention and the novel display device (the present liquid crystal display device and the present EL display device) including the present polarizing film are provided.

Finally, a projection type liquid crystal display device using this polarizing film will be described.
FIG. 11 is a schematic view showing a projection type liquid crystal display device using the present polarizing film.
This polarizing film is used as the polarizer 142 and / or the polarizer 143 of the projection type liquid crystal display device.

  A light bundle emitted from a light source (for example, a high-pressure mercury lamp) 111 that is a light emission source first passes through a first lens array 112, a second lens array 113, a polarization conversion element 114, and a superimposing lens 115. The luminance is uniformed and polarized in the cross section of the anti-beam bundle.

  Specifically, the light bundle emitted from the light source 111 is divided into a number of minute light bundles by the first lens array 112 in which minute lenses 112a are formed in a matrix. The second lens array 113 and the superimposing lens 115 are provided so that each of the divided light bundles irradiates the entire three liquid crystal panels 140R, 140G, and 140B that are illumination targets. The liquid crystal panel incident side surface has almost uniform illuminance as a whole.

  The polarization conversion element 114 is configured by a polarization beam splitter array, and is disposed between the second lens array 113 and the superimposing lens 115. As a result, random polarized light from the light source is converted into polarized light having a specific polarization direction in advance, thereby reducing the amount of light loss in the incident side polarizer described later, thereby improving the screen brightness.

  The light whose luminance is uniformed and polarized as described above is sequentially converted into the red channel, the green channel, and the blue channel by the dichroic mirrors 121, 123, and 132 for separation into the three primary colors of RGB via the reflection mirror 122. These are separated and enter the liquid crystal panels 140R, 140G, and 140B, respectively.

  In the liquid crystal panels 140R, 140G, and 140B, a polarizer 142 is disposed on the incident side, and a polarizer 143 is disposed on the exit side. This polarizing film can be used for the polarizer 142 and the polarizer 143.

  The polarizer 142 and the polarizer 143 arranged in the RGB optical paths are arranged so that the absorption axes thereof are orthogonal to each other. Each of the liquid crystal panels 140R, 140G, and 140B arranged in each optical path has a function of converting a polarization state controlled for each pixel by an image signal into a light amount.

  The polarizing film 100 is useful as a polarizing film having excellent durability in any optical path of a blue channel, a green channel, and a red channel by selecting a type of dichroic dye suitable for the corresponding channel.

  An optical image created by transmitting incident light with different transmittance for each pixel according to the image data of the liquid crystal panels 140R, 140G, and 140B is synthesized by the cross dichroic prism 150, and is projected by the projection lens 170 to the screen 180. Is enlarged and projected.

  Electronic paper is displayed by molecules such as optical anisotropy and dye molecule orientation, displayed by particles such as electrophoresis, particle movement, particle rotation, and phase change, and one end of the film moves And the like, those displayed by molecular color development / phase change, those displayed by light absorption of molecules, and those displayed by self-emission by combining electrons and holes. More specifically, microcapsule type electrophoresis, horizontal movement type electrophoresis, vertical movement type electrophoresis, spherical twist ball, magnetic twist ball, cylindrical twist ball method, charged toner, electronic powder fluid, magnetophoretic type, magnetic thermosensitive Formula, electrowetting, light scattering (transparency / translucency change), cholesteric liquid crystal / photoconductive layer, cholesteric liquid crystal, bistable nematic liquid crystal, ferroelectric liquid crystal, dichroic dye / liquid crystal dispersion type, movable film, leuco dye And color erasing, photochromic, electrochromic, electrodeposition, flexible organic EL, and the like. The electronic paper may be used not only for personal use of text and images but also for advertisement display (signage) or the like. According to this polarizing film, the thickness of the electronic paper can be reduced.

  As a stereoscopic display device, for example, a method of arranging different retardation films alternately like a micropole method has been proposed (Japanese Patent Laid-Open No. 2002-185983), but when the optical film of the present invention is used as a polarizing film, Since patterning is easy by printing, inkjet, photolithography, etc., the manufacturing process of the display device can be shortened, and a retardation film is not required.

  Hereinafter, the present invention will be described in more detail with reference to examples. Unless otherwise specified, “%” and “part” in the examples are mass% and part by mass.

In this example, the following polymerizable smectic liquid crystal compound was used.
Compound (2-6) (compound represented by the following formula (2-6))
Compound (2-6) was prepared according to Lub et al. Recl. Trav. Chim. It was synthesized by the method described in Pays-Bas, 115, 321-328 (1996).

(Measurement of phase transition temperature)
The phase transition temperature of the compound (2-6) was confirmed by determining the phase transition temperature of the film made of the compound (2-6). The operation is as follows.
A film made of the compound (2-6) was formed on the glass substrate on which the alignment film was formed, and the phase transition temperature was confirmed by texture observation with a polarizing microscope (BX-51, manufactured by Olympus Corporation) while heating. The film composed of the compound (2-6) is heated to 120 ° C., and when the temperature is lowered, the film transitions to the nematic phase at 112 ° C., the phase transition to the smectic A phase at 110 ° C., and the smectic B phase at 94 ° C. It was confirmed that the phase transition occurred.

Compound (2-8) (compound represented by the following formula (2-8))
Compound (2-8) was synthesized with reference to the synthesis of compound (2-6) described above.

(Measurement of phase transition temperature)
The phase transition temperature of compound (2-8) was confirmed in the same manner as in the measurement of the phase transition temperature of compound (2-6). Compound (2-8) had a temperature transition to 140 ° C., a temperature transition to a nematic phase at 131 ° C., a phase transition to a smectic A phase at 80 ° C., and a phase transition to a smectic B phase at 68 ° C. It was confirmed.

重合開始剤；
２−ジメチルアミノ−２−ベンジル−１−（４−モルホリノフェニル）ブタン−１−オン（イルガキュア３６９；チバスペシャルティケミカルズ社製） ６部
レベリング剤；
ポリアクリレート化合物（ＢＹＫ−３６１Ｎ；ＢＹＫ−Ｃｈｅｍｉｅ社製）
１．２部
溶剤；シクロペンタノン ２５０部 Example 1
(Preparation of composition for forming polarizing film)
The following components were mixed and stirred at 80 ° C. for 1 hour to obtain a composition for forming a polarizing film.
Polymerizable smectic liquid crystal compound; 75 parts of compound (2-6)
Compound (2-8) 25 parts Azo dye (1); Compound (1-8) 2.5 parts D10 dye described in JP-A-8-278409

A polymerization initiator;
2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one (Irgacure 369; manufactured by Ciba Specialty Chemicals) 6 parts Leveling agent;
Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie)
1.2 parts solvent; 250 parts cyclopentanone

(Measurement of phase transition temperature)
Compound (2-6) and compound (2-8) were mixed at a mass ratio of 75 parts: 25 parts.
Similarly to the case of compound (2-6) and compound (2-8), the phase transition temperature of the mixture prepared as described above was determined. After the temperature was raised to 140 ° C., the mixture was confirmed to undergo a phase transition to a nematic phase at 115 ° C., a phase transition to a smectic A phase at 105 ° C., and a phase transition to a smectic B phase at 75 ° C.

[Production and evaluation of this polarizing film]
1. Formation of Alignment Film A glass substrate was used as a transparent substrate.
On the glass substrate, a 2% by weight aqueous solution (alignment polymer composition) of polyvinyl alcohol (polyvinyl alcohol 1000 completely saponified type, manufactured by Wako Pure Chemical Industries, Ltd.) was applied by spin coating, dried, and then thickened. A 100 nm film was formed. Subsequently, an alignment film was formed by subjecting the surface of the obtained film to a rubbing treatment. The rubbing process uses a semi-automatic rubbing apparatus (trade name: LQ-008, manufactured by Joyo Engineering Co., Ltd.) and a push-in amount of 0.15 mm using a cloth (trade name: YA-20-RW, manufactured by Yoshikawa Chemical Co., Ltd.). , Under the conditions of 500 rpm and 16.7 mm / s. By such rubbing treatment, a laminate 1 having an alignment film formed on a glass substrate was obtained.

2. Formation of Polarizing Film The polarizing film forming composition is applied onto the alignment film of the laminate 1 by spin coating, heated and dried on a hot plate at 120 ° C. for 3 minutes, and then quickly cooled to room temperature. A dry film was formed on the alignment film. In such a dry film, the liquid crystal state of the polymerizable smectic liquid crystal compound was a smectic B phase. Next, by using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by Ushio Electric Co., Ltd.), the ultraviolet ray is irradiated to the dry film with an exposure amount of 2400 mJ / cm ² (365 nm standard), thereby polymerization contained in the dry film. The smectic liquid crystal compound was polymerized while maintaining the liquid crystal state, and a polarizing film was formed from the dried film. When the thickness of the polarizing film at this time was measured with a laser microscope (OLS3000 manufactured by Olympus Corporation), it was 1.7 μm.

3. X-ray diffraction measurement The polarizing film of the obtained laminate 2 was subjected to X-ray diffraction measurement using an X-ray diffractometer X'Pert PRO MPD (Spectris Co., Ltd.). X-rays generated under conditions of an X-ray tube current of 40 mA and an X-ray tube voltage of 45 kV using Cu as a target are rubbed through a fixed divergence slit 1/2 ° (the rubbing direction of the alignment film under the polarizing film in advance) As a result of scanning and measuring in steps of 2θ = 0.01671 ° in the scanning range of 2θ = 4.0 to 40.0 °, the measurement results in the vicinity of 2θ = 20.08 °. A sharp diffraction peak having a peak half width (FWHM) of about 0.312 ° was obtained. In addition, the same result was obtained even when incident from the rubbing vertical direction. The order period (d) obtained from the peak position was about 4.42 cm, and it was found that a structure reflecting a higher-order smectic phase was formed.

4). Measurement of dichroic ratio In order to confirm the usefulness of this polarizer, the dichroic ratio was measured as follows.
Using the apparatus which set the folder with a polarizer to the spectrophotometer (Shimadzu Corporation UV-3150) for the absorbance (A ¹ ) in the transmission axis direction and the absorbance (A ² ) in the absorption axis direction at the maximum absorption wavelength. Measured by the double beam method. The folder was provided with a mesh that cuts the light amount by 50% on the reference side. From the value of the absorbance of the measured transmission axis (A ¹⁾ and the absorption axis direction of the absorbance (A ^2), and calculates the ratio ^(A 2 ^/ A ^1), and a dichroic ratio. The results are shown in the table. It can be said that the higher the dichroic ratio, the more useful the polarizing film. Table 1 shows the measurement results of the maximum absorption wavelength of the absorbance (A ² ) in the absorption axis direction and the dichroic ratio at that wavelength.

In Examples 2 to 9 and Comparative Examples 1 to 3 and Reference Examples 1 to 4, a polarizing film was prepared in the same manner as in Example 1 except that the type of the azo dye (1) was changed, and the absorbance in the absorption axis direction ( The maximum absorption wavelength λMAX of A ² ) and the dichroic ratio at that wavelength were measured. The results are shown in Table 1.

Example 10
Polarized light in the same manner as in Example 1 except that (2-14) was used instead of compound (2-6) as a polymerizable smectic liquid crystal compound and (2-24) was used instead of compound (2-8). When the film was formed, the dichroic ratio at λMAX = 518 nm was 36.

Example 11
Polarized light in the same manner as in Example 2 except that (2-14) was used instead of compound (2-6) as a polymerizable smectic liquid crystal compound and (2-24) was used instead of compound (2-8). When the film was formed, the dichroic ratio at λMAX = 392 nm was 22.

Example 12
Polarization in the same manner as in Example 3, except that (2-14) was used instead of compound (2-6) as a polymerizable smectic liquid crystal compound and (2-24) was used instead of compound (2-8). When a film was formed, the dichroic ratio at λMAX = 536 nm was 40.

化合物（１−５） ２．５部

化合物（１−１５） ２．５部

重合開始剤；
２−ジメチルアミノ−２−ベンジル−１−（４−モルホリノフェニル）ブタン−１−オン（イルガキュア３６９；チバスペシャルティケミカルズ社製） ６部
レベリング剤；
ポリアクリレート化合物（ＢＹＫ−３６１Ｎ；ＢＹＫ−Ｃｈｅｍｉｅ社製）
１．２部
溶剤；シクロペンタノン ２５０部 Example 13
(Preparation of composition for forming polarizing film)
The following components were mixed and stirred at 80 ° C. for 1 hour to obtain a composition for forming a polarizing film.
Polymerizable smectic liquid crystal compound; 75 parts of compound (2-6)
Compound (2-8) 25 parts Azo dye (1); Compound (1-8) 2.5 parts

Compound (1-5) 2.5 parts

Compound (1-15) 2.5 parts

A polymerization initiator;
2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one (Irgacure 369; manufactured by Ciba Specialty Chemicals) 6 parts Leveling agent;
Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie)
1.2 parts solvent; 250 parts cyclopentanone

[Preparation of photo-alignment film on retardation film]
A retardation film (uniaxially stretched film WRF-S (modified polycarbonate resin), retardation value 137.1 nm, thickness 50 μm, manufactured by Teijin Chemicals Ltd.) is used as a transparent substrate, and a photo-alignment polymer of the following formula (3) A solution of 5% dissolved in cyclopentanone (a composition for forming a photoalignment film) was applied by a bar coating method and dried at 120 ° C. to obtain a dry film. On this dried film, polarized UV was irradiated in the direction of 45 ° with respect to the slow axis of the retardation film to obtain a photo-alignment film. The polarized UV treatment was performed using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by USHIO INC.) Under the condition that the intensity measured at a wavelength of 365 nm was 100 mJ.

[Production of circularly polarizing plate]
On the photo-alignment film, the polarizing film-forming composition was applied by a bar coating method, dried by heating in a drying oven at 120 ° C. for 1 minute, and then cooled to room temperature. In such a dry film, the liquid crystal state of the polymerizable smectic liquid crystal compound contained was a smectic B phase. Next, using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by USHIO INC.), An ultraviolet ray having an exposure amount of 2400 mJ / cm ² (365 nm standard) is irradiated onto the layer formed from the polarizing film forming composition. Thus, the polymerizable smectic liquid crystal compound contained in the dry film was polymerized while maintaining the liquid crystal state of the polymerizable smectic liquid crystal compound, and a polarizing film was formed from the dry film. When the film thickness of the polarizing film at this time was measured with a laser microscope (OLS3000 manufactured by Olympus Corporation), it was 1.6 μm.

<Measurement of optical properties>
When the ellipticity at wavelengths of 450.9 nm, 498.6 nm, 549.4 nm, 587.7 nm, and 627.8 nm was measured with respect to the circularly polarizing plate obtained above, almost circular polarization was obtained at any wavelength. It was confirmed.
450.9 nm = a / b = 0.841
498.6 nm = a / b = 0.889
549.4 nm = a / b = 0.968
587.7 nm = a / b = 0.924
627.8 nm = a / b = 0.852

  The polarizing film is extremely useful for producing a liquid crystal display device, an (organic) EL display device, and a projection type liquid crystal display device.

DESCRIPTION OF SYMBOLS 1 Transparent base material 2 Photo-alignment film 3 This polarizing film 100 Polarizer 101 1st laminated body 102 2nd laminated body 103 3rd laminated body 210 1st roll 210A winding core 220 2nd roll 220A winding core 211A, 211B Coating device 212A 212B Drying furnace 213A Polarized UV irradiation device 213B Light irradiation device 300 Auxiliary roll 10 Liquid crystal display devices 12a and 12b Polarizing films 13a and 13b Retardation films 14a and 14b Substrate 15 Color filter 16 Transparent electrode 17 Liquid crystal layer 18 Interlayer insulating film 19 Back Light unit 20 Black matrix 21 Thin film transistor 22 Pixel electrode 23 Spacer 24 Liquid crystal display device 30 EL display device 31 Polarizing film 32 Phase difference film 33 Substrate 34 Interlayer insulating film 35 Pixel electrode 36 Light emitting layer 37 Cathode electrode 38 Desiccant 39 Sealing lid 40 Thin film transistor 41 Rib 42 Thin film sealing film 44 EL display device 111 Light source 112 First lens array 112a Lens 113 Second lens array 114 Polarization conversion element 115 Superimposing lenses 121, 123, 132 Dichroic mirror 122 Reflection mirrors 140R, 140G, 140B Liquid crystal panels 142 and 143 Polarizer 150 Cross dichroic prism 170 Projection lens 180 Screen

Claims (9)

At least one polyazo dye having absorption in the wavelength range of 400 to 800 nm and represented by the following general formula (1):
A polarizing film formed from a composition containing a polymerizable smectic liquid crystal compound.

[In Formula (1),
n is 1 or 2.
Ar ₁ and Ar ₃ each independently represent a group selected from the groups shown below.

Ar ₂ represents a group selected from the following groups.

A ₁ and A ₂ each independently represent a group selected from the following groups.

(M is an integer of 0 to 10, and when there are two m's in the same group, these two m's are the same or different from each other.)]   The polarizing film according to claim 1, wherein the thickness is 1 μm or more and 5 μm or less.   The polarizing film according to claim 1, wherein a Bragg peak is obtained in X-ray diffraction measurement.   A polarizer comprising the polarizing film according to claim 1, an alignment film, and a transparent substrate in this order. A method for producing a polarizer comprising the polarizing film according to claim 1, an alignment film, and a transparent substrate in this order,
On the transparent substrate, preparing a laminate including the alignment film;
A film containing a polymerizable smectic liquid crystal compound, a polyazo dye represented by the general formula (1), a polymerization initiator and a solvent, on the alignment film of the laminate, having absorption in the wavelength range of 400 to 800 nm. Forming a step;
Removing the solvent from the film;
A step of bringing the polymerizable smectic liquid crystal compound contained in the film from which the solvent has been removed into a smectic liquid crystal state;
A process comprising: forming a polarizing film on the alignment film by polymerizing the polymerizable smectic liquid crystal compound while the polymerizable smectic liquid crystal compound maintains the smectic liquid crystal state.   A liquid crystal display device comprising the polarizing film according to claim 1. The circularly-polarizing plate which has the polarizing film in any one of Claims 1-3, and (lambda) / 4 layer, and satisfy | fills the requirements of the following (A1) and (A2).
(A1) The angle formed by the absorption axis of the polarizing film and the slow axis of the λ / 4 layer is approximately 45 °;
(A2) The value of the front retardation of the λ / 4 layer measured with light having a wavelength of 550 nm is in the range of 100 to 150 nm. The polarizing film according to claim 1, a λ / 2 layer, and a λ / 4 layer in this order, and the following (B1), (B2), (B3), and (B4) Circular polarizing plate that meets the requirements.
(B1) The angle formed by the absorption axis of the polarizing film and the slow axis of the λ / 2 layer is approximately 15 °;
(B2) The angle formed between the slow axis of the λ / 2 layer and the slow axis of the λ / 4 layer is approximately 60 °;
(B3) The value of the front retardation of the λ / 4 layer measured with light having a wavelength of 550 nm is in the range of 200 to 300 nm.
(B4) The λ / 4 layer is measured with light having a wavelength of 550 nm, and the value of the front retardation of the λ / 4 layer is in the range of 100 to 150 nm.   An organic EL display device comprising the circularly polarizing plate according to claim 7 and an organic EL element.

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