KR20180120131A - Polarizer and method for production thereof - Google Patents

Abstract

The present invention is to provide a novel polarizer and a manufacturing method thereof. The manufacturing method includes: a step of forming a film from a composition containing a polymerizable liquid crystal compound, a dichroic dye, a polymerization initiator and a solvent on the polarizing layer, wherein a polarizer is formed by disposing an orientation layer, the polarizing layer and a protective layer in this order on a transparent substrate; a step of removing the solvent from the film; a step of changing the polymerizable liquid crystal compound contained in the film having no solvent to a smectic liquid crystal state; and a step of polymerizing the polymerizable liquid crystal compound while maintaining the smectic liquid crystal state.

Description

[0001] POLARIZER AND METHOD FOR PRODUCTION THEREOF [0002]

The present invention relates to a polarizer, a manufacturing method thereof, and the like.

A polarizing element (polarizer) used in a liquid crystal display device includes an optical film such as a protective layer, a polarizing layer, and a transparent substrate. For example, Patent Document 1 discloses that a transparent resin protective layer (protective film), a light absorbing anisotropic layer (polarizing film) and a transparent film (transparent substrate) are laminated in this order on a transparent film Wherein the absorption anisotropic layer contains a dichroic dye having nematic liquid crystallinity of a specific structure.

[Patent Document 1] Japanese Patent Application Laid-Open No. 2010-152351

The present invention provides a novel polarizer and a method of producing the same.

The present invention includes the following [1] to [14] inventions.

[1] A polarizer provided with an orientation layer, a polarizing layer and a protective layer in this order on a transparent substrate,

Wherein the polarizing layer

A step of forming a film from a composition comprising a polymerizable liquid crystal compound, a dichroic dye, a polymerization initiator and a solvent;

Removing the solvent from the film,

A step of bringing the polymerizable liquid crystal compound contained in the film from which the solvent has been removed into a smectic liquid crystal state,

And a step of polymerizing the polymerizable liquid crystal compound while maintaining the state of the smectic liquid crystal state.

[2] The polarizer according to the above [1], wherein the polarizing layer is a polarizing layer in which a black peak can be obtained in X-ray diffraction measurement.

[3] The polarizer according to [1] or [2], wherein the thickness of the polarizing layer is in the range of 0.5 탆 to 3 탆.

[4] The polarizer according to any one of [1] to [3], wherein the dichroic dye is an azo dye.

[5] The polarizer according to any one of [1] to [4], wherein the polymerizable liquid crystal compound comprises two or more polymerizable stymatic liquid crystal compounds.

[6] The method according to any one of [1] to [5], wherein the protective layer is formed from a protective layer composition comprising a polyfunctional acrylate and a solvent, and the solvent is substantially composed of an alcohol solvent and / Polarizer.

[7] The polarizer according to any one of [1] to [5], wherein the protective layer is formed from a composition for forming a protective layer containing a polymer or oligomer obtained by polymerizing a polyfunctional acrylate and water.

[8] The polarizer according to any one of [1] to [5], wherein the protective layer is formed from a composition for forming a protective layer containing a water-soluble polymer and water.

[9] A liquid crystal display device comprising the polarizer according to any one of [1] to [8].

[10] The liquid crystal display according to [9], wherein the polarizer is arranged inside a liquid crystal cell.

[11] A circular polarizer provided with a quarter-wave plate on the protective layer of the polarizer according to any one of [1] to [8].

[12] The circular polarizer according to the above-mentioned [11], wherein the 1/4 wavelength plate is a wavelength plate having a property that the in-plane retardation value for visible light becomes smaller as the wavelength becomes shorter.

[13] An organic EL display device comprising the circularly polarizing plate according to [11] or [12] and an organic EL device.

(14) A method of manufacturing a liquid crystal display device, comprising the steps of: (1) forming an alignment layer on a transparent substrate to form a laminate;

(2) of applying a composition containing a polymerizable liquid crystal compound, a dichroic dye and a polymerization initiator on the alignment layer of the laminate to form a first coating film on the alignment layer,

The first coating film formed in the step (2) is dried under a condition that the polymerizable liquid crystal compound contained in the first coating film is not polymerized to form a first dried film, and the polymerization (3) of forming a polarizing layer from the first dried film by polymerizing the polymerizable liquid crystal compound while keeping the liquid crystal compound in the smectic liquid crystal state and maintaining the state of the smectic liquid crystal,

A protective layer composition containing a polyfunctional acrylate and a solvent is coated on the polarizing layer formed in the step (3) to form a second coating film on the polarizing layer, and the second coating film (4) of polymerizing a polyfunctional acrylate to form a protective layer from the second coating film.

[15] The process for producing a polarizer according to [14], wherein the solvent contained in the protective layer composition is substantially composed of an alcohol solvent and / or an ether solvent.

A step (1) of forming a laminate by providing an orientation layer on a transparent substrate;

(2) of applying a composition containing a polymerizable liquid crystal compound, a dichroic dye and a polymerization initiator on the alignment layer of the laminate to form a first coating film on the alignment layer,

The first coating film formed in the step (2) is dried under a condition that the polymerizable liquid crystal compound contained in the first coating film is not polymerized to form a first dried film, and the polymerization (3) of forming a polarizing layer from the first dried film by polymerizing the polymerizable liquid crystal compound while keeping the liquid crystal compound in the smectic liquid crystal state and maintaining the state of the smectic liquid crystal,

Coating a composition for forming a protective layer containing a polymer or oligomer obtained by polymerizing a polyfunctional acrylate with water on the polarizing layer formed in the step (3), forming a second coating film on the polarizing layer, And a step (4) of forming a protective layer from the second coating film by drying the second coating film.

(1) a step of forming a laminate by providing an orientation layer on a transparent substrate,

(2) of applying a composition containing a polymerizable liquid crystal compound, a dichroic dye and a polymerization initiator on the alignment layer of the laminate to form a first coating film on the alignment layer,

The first coating film formed in the step (2) is dried under a condition that the polymerizable liquid crystal compound contained in the first coating film is not polymerized to form a first dried film, and the polymerization (3) of forming a polarizing layer from the first dried film by polymerizing the polymerizable liquid crystal compound while keeping the liquid crystal compound in the smectic liquid crystal state and maintaining the state of the smectic liquid crystal,

A composition for forming a protective layer containing a water-soluble polymer and water is applied onto the polarizing layer formed in the step (3) to form a second coating film on the polarizing layer, and the second coating film is dried, And a step (4) of forming a protective layer from the second coating film.

[18] A polarizer produced by the production method according to any one of [14] to [17] above.

According to the present invention, there is provided a polarizer comprising a novel polarizing layer.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic view schematically showing a cross-sectional structure of a polarizer of the present invention. FIG.
2 is a schematic view schematically showing a sectional configuration of a liquid crystal display device using the polarizer of the present invention.
3 is a schematic view schematically showing the order of layers of the polarizer of the present invention provided in a liquid crystal display device.
4 is a schematic view schematically showing the order of layers of the polarizer of the present invention provided in a liquid crystal display device.
5 is a schematic view schematically showing a sectional configuration of a liquid crystal display device (in-cell type) using the polarizer of the present invention.
6 is a schematic view schematically showing a sectional configuration of an EL display device using the polarizer of the present invention.
7 is a schematic view schematically showing a manufacturing method of an EL display device using the polarizer of the present invention.
8 is a schematic view schematically showing the order of layers of the polarizer of the present invention provided in the EL display device.
9 is a schematic view schematically showing the cross-sectional structure of an EL display device using the polarizer of the present invention.
10 is a schematic view showing a projection type liquid crystal display device using the polarizer of the present invention.

The polarizer of the present invention (hereinafter occasionally referred to as " present polarizer ") comprises an orientation layer, a polarizing layer and a protective layer arranged in this order on a transparent substrate,

A step of forming a coating film from a composition comprising a polymerizable liquid crystal compound, a dichroic dye, a polymerization initiator and a solvent;

Removing the solvent from the coating film,

A step of bringing the polymerizable liquid crystal compound contained in the coating film from which the solvent is removed into a smectic liquid crystal state,

And a step of polymerizing the polymerizable liquid crystal compound while maintaining the state of the smectic liquid crystal state.

A preferred embodiment of the method for producing the polarizer will be described with reference to drawings as necessary. In a preferred embodiment of this manufacturing method,

(1) of forming a laminate by providing an orientation layer on a transparent substrate,

(2) of applying a composition containing a polymerizable liquid crystal compound, a dichroic dye, and a polymerization initiator on the alignment layer of the laminate formed in the step (1) to form a first coating film on the alignment layer, Wow,

The first coating film formed in the step (2) is dried under a condition that the polymerizable liquid crystal compound contained in the first coating film is not polymerized to form a first dried film, and the polymerizable liquid crystal compound (3) of forming a polarizing layer from the first dried film by polymerizing the polymerizable liquid crystal compound while keeping the liquid crystal compound in a smectic liquid crystal state and maintaining the smectic liquid crystal state,

A protective layer composition comprising a polyfunctional acrylate and a solvent is applied on the polarizing layer formed in the step (3) to form a second coating film on the polarizing layer, and the second coating film (4) of forming a protective layer from the second coating film by polymerizing a polyfunctional acrylate. Hereinafter, such a production method will be described step by step.

<Transparent substrate>

In the method for producing the polarizer, first, a transparent substrate is prepared. This transparent base material is a base material having transparency enough to transmit light, particularly visible light. This transparency refers to a characteristic that the transmittance to a light beam having a wavelength ranging from 380 nm to 780 nm is 80% or more. Specifically, examples of such a transparent substrate include a glass substrate, a light transmitting sheet made of plastic, and a light transmitting film. Examples of the plastic constituting the light transmitting sheet and the light transmitting film include polyolefins such as polyethylene, polypropylene and norbornene polymer; A cyclic olefin resin; Polyvinyl alcohol; Polyethylene terephthalate; Polymethacrylic acid esters; Polyacrylic acid esters; Cellulose esters such as triacetylcellulose, diacetylcellulose and cellulose acetate propionate; Polyethylene naphthalate; Polycarbonate; Polysulfone; Polyethersulfone; Polyether ketones; Polyphenylene sulfide, polyphenylene oxide, and the like. Of the specific examples of the above-mentioned transparent base materials, among the translucent sheet and translucent film made of plastic, a translucent film made of plastic, that is, a polymer film is preferable. Among these polymer films, a polymer film (cellulose ester film or cycloolefin-based resin film) composed of a cellulose ester or a cyclic olefin-based resin is preferable in view of being easily available on the market or having excellent transparency. In producing the present polarizer using such a transparent substrate, it is preferable that the transparent substrate is adhered to the transparent substrate in view of being easily handled without causing breakage such as tearing when the transparent substrate is transported or stored You can leave it. The thickness of the transparent substrate may be such that the transparency described above can be exhibited. When a polymer film is used as the transparent substrate, the polymer film may be given a function as a retardation film by stretching treatment or the like. The case of imparting a function as a retardation film to the transparent base material will be described later.

The cellulose ester film and the cycloolefin resin film will be described in more detail. Of these two types, the cyclic olefin based resin film is preferable in that it is easy to control the retardation value when the function as the retardation film is imparted.

In the cellulose ester constituting the cellulose ester film, at least a part of the hydroxyl groups contained in the cellulose is acetic esterified. A cellulose ester film composed of such a cellulose ester is easily available on the market. Examples of commercially available cellulose ester films (triacetylcellulose films) include "Fuji Tackfilm" (Fuji Shashin Film Co., Ltd.); "KC8UX2M", "KC8UY" and "KC4UY" [Konica Minolta Opt Co., Ltd.]. Such a commercially available cellulose film can be used as a transparent substrate after being subjected to a surface treatment such as antiglare treatment, hard coat treatment, antistatic treatment or antireflection treatment, as is or if necessary.

In order to impart the retardation to the polymer film, the polymer film is stretched or the like as described above. A plastic film, that is, a polymer film made of a thermoplastic resin can all be subjected to a stretching treatment, but a cyclic olefin based resin film is preferable because it is easy to give a retardation. The cyclic olefin resin constituting the cyclic olefin based resin film is, for example, composed of a polymer or copolymer (cyclic olefin resin) of a cyclic olefin such as norbornene or a polycyclic norbornene-based monomer. The cyclic olefin- And may include an opening portion. It may also be a hydrogenated cycloolefin resin containing a ring-opening. The cyclic olefin resin may be a copolymer of a cyclic olefin and a chain olefin or a vinyl aromatic compound (such as styrene) in view of not significantly impairing transparency, but not significantly increasing hygroscopicity. The cyclic olefin resin may have a polar group introduced into the molecule.

When the cyclic olefin resin is a copolymer of a cyclic olefin and an aromatic compound or a chain olefin having a vinyl group, examples of the chain olefin include ethylene and propylene. Examples of the vinylated aromatic compound include styrene,? -Methylstyrene, . In such a copolymer, the content ratio of the structural units derived from the cyclic olefin is in the range of about 50 mol% or less, for example, about 15 to 50 mol%, based on the total structural units of the cyclic olefin-based resin. In the case where the cyclic olefin resin is a ternary copolymer obtained from a cyclic olefin, a chain olefin and a vinylated aromatic compound, for example, the content ratio of the structural unit derived from a chain olefin is preferably from 5 to 100 parts by weight based on the total structural units of the cyclic olefin- 80 mol%, and the content ratio of the structural unit derived from the vinyl aromatic compound is about 5 to 80 mol%. The cycloolefin resin of the terpolymer has an advantage that the amount of the expensive cycloolefin can be relatively small when the cycloolefin resin is produced.

The cyclic olefin resin capable of producing the cyclic olefin based resin film can be easily obtained from the market. Commercially available cyclic olefin resins include "Topas" (Ticona, Germany); "Atton" [JSR Corporation]; "ZEONOR" and "ZEONEX" [Nippon Zeon Co., Ltd.]; "Arpel" (manufactured by Mitsui Kagaku Co., Ltd.) and the like. Such a cycloolefin resin can be formed into a film (cyclic olefin resin film) by a known film-forming means such as a solvent casting method or a melt extrusion method. In addition, a cyclic olefin based resin film that has already been commercially available in the form of a film can also be used. Examples of commercially available cyclic olefin based resin films include "Essener" and "SCA40" (manufactured by Sekisui Chemical Co., Ltd.); "Zeonoah Film" [Optis Co., Ltd.]; And "Aton film" [JSR Co., Ltd.]. Here, all items described in "" are trade names, and the same shall apply hereinafter.

Next, a method of imparting the phase difference to the polymer film will be briefly described. The polymer film can impart retardation by a known stretching method. For example, a winding body in which a polymer film is wound on a roll is prepared, the film is continuously wound from the winding body, and the wound film is conveyed to a heating furnace. The set temperature of the heating furnace is preferably in the range of the vicinity of the glass transition temperature (° C) of the plastic constituting the polymer film to the [glass transition temperature +100] (° C), preferably in the vicinity of the glass transition temperature (° C) Temperature + 50] (占 폚). In the heating furnace, when the film is stretched in the advancing direction of the film or in the direction orthogonal to the advancing direction, the uniaxial or biaxial stretch processing is performed by tilting the film in an arbitrary angle by adjusting the conveying direction and the tension. The draw ratio is usually in the range of about 1.1 to 6 times, and preferably in the range of about 1.1 to 3.5 times. The method of stretching in the oblique direction is not particularly limited as long as it can continuously tilt the orientation axis at a desired angle, and a known stretching method can be employed. Such a stretching method is, for example, a method disclosed in Japanese Patent Application Laid-Open No. 50-83482 or Japanese Patent Laid-open No. Hei 2-113920.

In the use as a transparent substrate, the thickness of the polymer film is preferably as small as possible in terms of weight enough to be practically handled and sufficient transparency can be ensured. However, when the polymer film is too thin, The workability tends to be poor. Therefore, suitable thicknesses of these films are, for example, about 5 탆 to 200 탆, and preferably 20 탆 to 100 탆. When this polarizer is used as a circularly polarizing plate described later, when the display device using this circularly polarizing plate is used for a mobile application, the thickness of the film is particularly preferably about 20 to 80 mu m. When retardation is imparted to the film by stretching, the thickness after stretching is determined by the thickness of the film before stretching and the stretch magnification.

&Lt; Process (1) >

In the step (1), by providing an alignment layer on the above-mentioned transparent substrate, a laminate having a transparent substrate and an alignment layer, preferably a laminate of a transparent substrate and an alignment layer, is formed. When the transparent substrate is subjected to a surface treatment such as a hard coat treatment or an anti-glare treatment, an orientation layer may be formed on the surface opposite to the surface side.

<Orientation Layer>

It is preferable that the orientation layer is not significantly denatured in the process of forming a polarizing layer described later. As a method of forming the alignment layer, a method of using an orienting polymer capable of imparting an alignment restraining force by rubbing (hereinafter referred to as &quot; rubbing method &quot; in some cases), a method of irradiating polarized light A method of forming an alignment layer by obliquely depositing silicon oxide on a transparent substrate (transparent substrate surface) by a method using an orientation polymer (hereinafter referred to as &quot; photo alignment method &quot; And a method of forming an alignment layer by forming a monomolecular film having a long-chain alkyl group using the Broget method (LB method). Among them, the rubbing method and the photo alignment method are preferable in that an orientation layer excellent in orientation uniformity can be obtained, a processing time required for forming an orientation layer, and a processing cost are preferable. As the alignment layer, there is preferably used an alignment layer having a solvent resistance to such a degree that it is not dissolved in a solvent contained in a composition (a composition for forming a polarizing layer described below) applied in a subsequent step, heat resistance against heat treatment in forming a polarizing layer, It is preferable to have sufficient adhesiveness to the substrate. In addition, when the alignment layer is imparted with an alignment restraining force by a rubbing method or the like, friction is applied to the coating layer for forming the alignment layer. Therefore, the coating film for forming an alignment layer or the compound For example, an orientation polymer described later) is deformed by the friction or the like, or the orientation layer itself does not peel off from the transparent substrate due to the friction or the like. From the viewpoint of easily forming such an orientation layer, it is preferable to form an orientation layer from a composition containing an orientation polymer or an orientation polymer, or from a composition containing a photo-orientation polymer or a photo-orientable polymer.

Hereinafter, the orientation polymer for forming an alignment layer and the photo-orientable polymer will be described.

Preferred examples of the oriented polymer include a polyamide having an amide bond in a molecule; Gelatin; A polyimide having an imide bond in a molecule and a polyamic acid as a hydrolyzate thereof; Polyvinyl alcohol; Alkyl-modified polyvinyl alcohol; Polyacrylamides; Polyoxazole; Polyethylene imine; polystyrene; Polyvinylpyrrolidone; And polymers such as polyacrylic acid and polyacrylic acid esters. These polymers may be used alone or in combination of two or more to form an orientation layer, or a copolymer having a plurality of structural units constituting these polymers may be used for forming an orientation layer. As described above, preferred examples of the oriented polymer are shown. Of these, polyvinyl alcohol is particularly preferable as the oriented polymer. These oriented polymers may be polymerized by known polymerization methods such as polycondensation by dehydration polymerization, deamination polymerization, or the like, chain polymerization such as radical polymerization, anion polymerization and cation polymerization, coordination polymerization or ring-opening polymerization Can be easily produced.

As the photo-orientable polymer, a polymer having a photosensitive structure is used. When the polymer having the photosensitive structure is irradiated with the polarized light, the photosensitive structure of the irradiated portion is isomerized or crosslinked to orient the photo-orientable polymer, and as a result, the alignment regulating force is imparted to the film made of the photo- Examples of the photosensitive structure include azobenzene structure, maleimide structure, calcon structure, cinnamic acid structure, 1,2-vinylene structure, 1,2-acetylene structure, spiropyran structure, spirobenzopyran structure, and fulgide structure And the like. The polymer having any one of the photosensitive structures selected from these may be used alone or in combination of two or more in the formation of the alignment layer. These photo-orientable polymers can be produced by polymerizing a monomer (monomer) having a photosensitive structure by a polymerization method such as polycondensation by dehydration polymerization or deamination polymerization, chain polymerization such as radical polymerization, anion polymerization and cation polymerization, Can be easily produced by selecting a known polymerization method. Further, a plurality of kinds of monomers having different photosensitive structures may be used as a copolymer.

As a method for forming the orientation layer from the orientation polymer or the photo-orientable polymer, a method of preparing a composition in which the orientation polymer or the photo-orientable polymer is dissolved in a solvent is prepared, and the composition is used from the viewpoint of simplicity of operation. Hereinafter, the composition capable of forming this alignment layer is sometimes referred to as a &quot; composition for forming an orientation layer &quot;. When the composition for forming an orientation layer is applied to, for example, a transparent substrate and the solvent is removed from the coated film by a heating operation or a depressurizing operation, an orientation layer can be easily provided on the transparent substrate. The solvent used in the composition for forming an orientation layer may be appropriately selected depending on the kind and amount of the orienting polymer and the photo-orientable polymer to be used, and specific examples thereof include 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,? -Butyrolactone, propylene glycol methyl ether acetate and ethyl lactate; Ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone and methyl isobutyl ketone; Aliphatic hydrocarbon solvents such as pentane, hexane and heptane; Aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; Ether solvents such as tetrahydrofuran and dimethoxyethane; Chlorinated hydrocarbons such as chloroform and chlorobenzene, and the like. These solvents may be used alone or in combination of plural kinds.

In addition, a commercially available composition for forming an alignment layer may be used for forming the alignment layer. Examples of commercially available composition for forming an alignment layer include "Sunever" (manufactured by Nissan Chemical Industries, Ltd.) and "Optomer" (manufactured by JSR Corporation). Use of such a commercially available composition for forming an orientation layer is advantageous in that it can form an orientation layer with less unevenness and can form an orientation layer having good environmental resistance and mechanical resistance.

As a method for forming an alignment layer using a composition for forming an alignment layer, a composition for forming an alignment layer is coated on a transparent substrate, and then the substrate is subjected to heat treatment (annealing) to form an alignment layer Thereby forming a coating film. The thickness of the thus obtained coating film for forming an alignment layer is determined so that the alignment layer obtained after imparting the alignment regulating force has a desired thickness. The thickness of this alignment layer is, for example, 10 nm to 10,000 nm, preferably 10 nm to 1000 nm. The thickness of such an orientation layer can be controlled by adjusting conditions for applying the composition for forming an orientation layer.

Further, rubbing or polarized light irradiation is performed on the coating film for forming the alignment layer in order to form an alignment layer by imparting an appropriate alignment regulating force to the coating film for forming the alignment layer. By giving the alignment regulating force, the polymerizable liquid crystal compound contained in the coating film (first coating film) for forming a polarizing layer described later can be oriented in a desired direction. Further, as will be described later, when a plurality of polymerizable liquid crystal compounds are contained in the first coating film, that is, when a polymerizable liquid crystal mixture is contained, the polymerizable liquid crystal mixture is oriented in a desired direction .

As a method of rubbing the coating film for forming the alignment layer, for example, a rubbing roll in which a rubbing cloth is wound and rotated is prepared, and a laminate on which the coating film (coating film for forming an orientation layer) is formed is placed on a stage The film is transported toward the rubbing roll which is rotating so that the coating film is brought into contact with the rotating rubbing roll. Further, even when polarized light (preferably polarized UV) is applied to a coating film for forming an alignment layer (photo-alignment layer), an alignment restricting force may be given to the coated film. When masking is performed in rubbing or polarized light irradiation, a plurality of regions (patterns) having different directions of slow axes may be formed on the resulting polarizers.

&Lt; Process (2) >

In the step (2), a polarizing layer is provided on the alignment layer formed as described above.

The polarizing layer of the present polarizer is formed by the above-described method. This method will be described repeatedly. First, a composition containing a polymerizable liquid crystal compound, a dichroic dye, a polymerization initiator and a solvent (hereinafter, referred to as a "polarizing layer forming composition" in some cases) is applied on the alignment layer to form a first coating film , The first coating film is dried and the solvent is removed to form the first drying film. Thereafter, the polarizing layer is formed by polymerizing the polymerizable liquid crystal compound in the first dried film while maintaining the liquid crystal state of the smectic phase. In order to polymerize the polymerizable liquid crystal compound while maintaining the smectic liquid crystal state as described above, the phase transition temperature of the polymerizable liquid crystal compound to be used first is measured, a temperature at which the smectic phase can be maintained is determined, It is preferable to polymerize the polymerizable liquid crystal compound, but the polymerization temperature at which the polymerizable liquid crystal compound is polymerized is preferably as low as possible. The measurement conditions of this phase transition temperature measurement will be described in the embodiments of the present invention.

The thickness of the polarizing layer is usually in the range of 0.5 탆 to 10 탆, more preferably in the range of 0.5 탆 to 3 탆. Therefore, the thickness of the first coating film is determined in consideration of the thickness of the polarizing layer to be obtained. The thickness of the polarizing layer can be obtained by measurement of an interference film thickness meter, a laser microscope or an acupressure type film thickness meter.

The polymerizable liquid crystal compound contained in the composition for forming a polarizing layer is a compound having a polymerizable group and exhibiting liquid crystallinity. The polymerizable group means a group participating in the polymerization reaction of the polymerizable liquid crystal compound.

As the above-mentioned smith images, there are 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, And a smectic L phase. Of these, high-order smectic phases such as a smectic B phase, a smectic F phase, a smectic I phase, a slanted smectic F phase and a slanted smectic I phase are preferable, and a smectic B phase is more preferable. A polarizing layer having a high degree of alignment can be formed by using a composition for forming a polarizing layer in which the liquid crystal phase represented by the polymerizable liquid crystal compound can be a liquid crystal phase thereof.

The preferred polymerizable liquid crystal composition includes, for example, a compound represented by the formula (1) [hereinafter referred to as &quot; compound (1) &quot;

U ¹ -V ¹ -W ¹ -X ¹ -Y ¹ -X ² -Y ² -X ³ -W ² -V ² -U ² (1)

In the above formula (1)

X ¹ , X ² and X ³ independently represent a p-phenylene group which may have a substituent or a cyclohexane-1,4-diyl group which may have a substituent. Provided that 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 are each independently -CH ₂ CH ₂ -, -CH ₂ O-, -COO-, -OCOO-, a single bond, -N = N-, -CR ^a = CR ^b - C- or -CR &^lt; ^a &gt; = N-. R ^a and R ^b 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 independently represent a single bond, -O-, -S-, -COO- or -OCOO-.

V ¹ and V ² independently represent an alkanediyl group having 1 to 20 carbon atoms which may have a substituent, and -CH ₂ - constituting the alkanediyl group is substituted with -O-, -S- or -NH- .

In the compound (1), as described above, at least one of X ¹ , X ² and X ³ is a 1,4-phenylene group which may have a substituent, but two or more of them may have a substituent More preferred is a good p-phenylene group.

The p-phenylene group is preferably an amorphous group. The cyclohexane-1,4-diyl group is preferably a trans-cyclohexane-1,4-diyl group, more preferably an indeterminate group.

Examples of the substituent optionally having a p-phenylene group or a cyclohexane-1,4-diyl group include an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group and a butyl group; Cyano; Halogen atoms and the like. Further, -CH ₂ - constituting the cyclohexanoic acid-1,4-diyl group may be substituted with -O-, -S- or -NR-. R is an alkyl group having 1 to 6 carbon atoms or a phenyl group.

Y ¹ of compound (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, preferably a polymerizable group. That is, both U ¹ and U ² are preferably a polymerizable group, and more preferably all of them are photopolymerizable groups. Here, the photopolymerizable group means a group capable of participating in the polymerization reaction by an active radical or an acid generated from a photopolymerization initiator described later. Use of a polymerizable liquid crystal compound having a photopolymerizable group is also advantageous in that the polymerizable liquid crystal compound can be polymerized at a lower temperature.

In the compound (1), the photopolymerizable groups of U ¹ and U ² may be different from each other, but are preferably groups of the same kind. Examples of the photopolymerizable group include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group and oxetanyl group . Among them, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group and an oxetanyl group are preferable, and an 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- A heptane-1,7-diyl group, an octane-1,8-diyl group, a decane-1,10-diyl group, a tetradecane-1,14-diyl group, An acid-1,20-diyl group and the like. V ¹ and V ² are preferably an alkanediyl group having ² to 12 carbon atoms, more preferably an alkanediyl group having 6 to 12 carbon atoms.

As the substituent optionally possessed by the alkanediyl group, a cyano group, a halogen atom and the like can be mentioned, but the alkanediyl group is preferably an amorphous group, more preferably an unsubstituted straight-chain alkanediyl group.

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

Examples of the compound (1) include compounds represented by any one of formulas (1-1) to (1-21). When the specific example of the compound (1) has a cyclohexane-1,4-diyl group, it is preferable that the cyclohexane-1,4-diyl group is a trans.

The exemplified compound (1) [polymerizable liquid crystal compound] can be used alone or as a polymerizable liquid crystal mixture in which two or more kinds are mixed. In addition, as described above, the phase transition temperature of the compound (1) is determined, and the component (1) other than the polymerizable liquid crystal compound of the composition for forming a polarizing layer can be polymerized so that the compound . Examples of the component capable of controlling the polymerization temperature include a photopolymerization initiator, a photosensitizer and a polymerization inhibitor which will be described later. The polymerization temperature of the compound (1) can be controlled by suitably controlling the kind and amount thereof. Further, even when a mixture of two or more compounds (1), that is, a polymerizable liquid crystal mixture, is used in the composition for forming a polarizing layer, the phase transition temperature of the polymerizable liquid crystal mixture is determined and then the same as in the case of the polymerizable liquid crystal compound To control the polymerization temperature.

Examples of the polymerizable liquid crystal compound used in the composition for forming a polarizing layer include compounds represented by formulas (1-3), (1-6), (1-7), (1-12), Is preferably represented by the formula (1-13). These compounds (1) can be obtained by polymerizing (1) the above-mentioned compound (1) under a temperature condition that easily undergoes a phase transition temperature lower than the phase transition temperature by interaction with all of the used photopolymerization initiators, . More specifically, by interacting with the photopolymerization initiator, these compounds (1) can be polymerized under a temperature condition of 70 DEG C or lower, preferably 60 DEG C or lower, while sufficiently maintaining a high-order smectic phase liquid crystal state .

As described above, the polymerizable liquid crystal compound contained in the composition for forming a polarizing layer may be a single species or a plurality of species, preferably a plurality of species, more preferably a plurality of species in the exemplified compound (1). The polymerizable liquid crystal compound contained in the composition for forming a polarizing layer is preferably a polymerizable smectic liquid crystal compound and preferably contains a plurality of polymerizable smectic liquid crystal compounds. The compounds (1) represented by the above-mentioned formulas (1-1) to (1-21) all correspond to a polymerizable smectic liquid crystal compound.

The content of the polymerizable liquid crystal compound in the composition for forming a polarizing layer is preferably 70 to 99.9 mass%, more preferably 90 to 99.9 mass%, based on the solid content of the composition for forming a polarizing layer. If the content of the polymerizable liquid crystal compound is within the above range, the alignment property of the polymerizable liquid crystal compound tends to be high. Here, the solid content refers to the total amount of components excluding the volatile component such as a solvent from the composition for forming a polarizing layer. When the compound (1) is used as the polymerizable liquid crystal compound, the content of the compound (1) in the composition for forming a polarizing layer may be in the above range. When a plurality of compounds (1) are contained in the composition for forming a polarizing layer, the total content ratio may be in the above range.

The composition for forming a polarizing layer preferably contains a leveling agent. This leveling agent has a function of adjusting the fluidity of the polymerizable liquid crystal compound and making the first coating film obtained by applying the composition for forming a polarizing layer more flat. As the leveling agent, a surfactant or the like can be used. The leveling agent is more preferably at least one selected from the group consisting of a leveling agent containing a polyacrylate compound as a main component and a leveling agent containing a fluorine atom-containing compound as a main component.

As a leveling agent containing a polyacrylate compound as a main component, there may be mentioned "BYK-350", "BYK-352", "BYK-353", "BYK-354", "BYK- 381 ", " BYK-381 ", and "BYK-392 " [BYK Chemie Co., Ltd.].

As a leveling agent containing a fluorine atom-containing compound as a main component, "Megapack R-08", "Megapack R-30", "Megapack R-90", "Megafac F- , "Megapack F-477", "Megapack F-479", "Megapack F-471", "Megapack F- "Megapack F-482" and "Megapack F-483" [DIC Co., Ltd.]; Surfron S-381, Surfron S-382, Surfron S-383, Surfron S-393, Surfron SC-101, Surfron SC- -40 "and" SA-100 "[AGC Seiyam Chemical Co., Ltd.]; "E1830 "," E5844 "[Daikin Fine Chemical Co., Ltd .; , "EF Top EF301", "EF Top EF303", "EF Top EF351" and "EF Top EF352" [Mitsubishi Materials Tenshikasai Co., Ltd.].

When the leveling agent is contained in the composition for forming a polarizing layer, the content thereof is preferably not less than 0.3 parts by mass and not more than 5 parts by mass, more preferably not less than 0.5 parts by mass and not more than 3 parts by mass relative to 100 parts by mass of the polymerizable liquid crystal compound desirable. When the content of the leveling agent is within the above-mentioned range, the polymerizable liquid crystal composition is easily aligned in a horizontal direction, and the obtained polarizing layer tends to be smoother. On the other hand, when the content of the leveling agent in the polymerizable liquid crystal compound exceeds the above-mentioned range, unevenness tends to occur in the obtained polarizing layer. The composition for forming a polarizing layer may contain two or more kinds of leveling agents.

The composition for forming a polarizing layer contains a dichroic dye. The dichroic dye referred to here refers to a dye having a property that the absorbance in the major axis direction of the molecule is different from the absorbance in the minor axis direction. The dichroic dye is not particularly limited as long as it has such properties, and may be a dye or a pigment. A plurality of dyes may be used, a plurality of dyes may be used, or a combination of dyes and pigments may be used.

It is preferable that the dichroic dye has a maximum absorption wavelength (λMAX) in the range of 300 nm to 700 nm. Examples of such a dichroic dye include an acridine dye, an oxazine dye, a cyanine dye, a naphthalene dye, an azo dye, and an anthraquinone dye. Among them, an azo dye is preferable. Examples of the azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes and stilbenazo dyes, and preferred are bisazo dyes and trisazo dyes.

The azo dye includes, for example, a compound represented by the formula (2) [hereinafter referred to as &quot; compound (2) &quot;

A ¹ (-N = NA ² ) _p -N = NA ³ (2)

In the above formula (2)

A ¹ and A ³ independently represent a phenyl group which may have a substituent, a naphthyl group which may have a substituent or a monovalent heterocyclic group which may have a substituent. A ² represents a p-phenylene group which may have a substituent, a naphthalene-1,4-diyl group which may have a substituent, or a divalent heterocyclic group which may have a substituent. p represents an integer of 1 to 4; When p is 2 or more, a plurality of A ^{2 s} may be the same or different.

Examples of the monovalent heterocyclic group include groups in which one hydrogen atom has been removed from heterocyclic compounds such as quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzoimidazole, oxazole and benzoxazole. The group in which two hydrogen atoms are removed from the heterocyclic compound corresponds to a divalent heterocyclic group, and specific examples of such heterocyclic compounds are as described above.

As the substituent optionally having a phenyl group, a naphthyl group and a monovalent heterocyclic group in A ¹ and A ³ and a p-phenylene group, a naphthalene-1,4-diyl group and a divalent heterocyclic group in A ² , An alkyl group having 1 to 4 carbon atoms; An alkoxy group having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group and a butoxy group; A fluorinated alkyl group having 1 to 4 carbon atoms such as a trifluoromethyl group; Cyano; A nitro group; A halogen atom; A substituted or unsubstituted amino group such as an amino group, a diethylamino group and a pyrrolidino group (the substituted amino group means an amino group having one or two alkyl groups having 1 to 6 carbon atoms or two substituted alkyl groups, An amino group forming an alkanediyl group, and an unsubstituted amino group is -NH ₂ . Specific examples of the alkyl group having 1 to 6 carbon atoms are the same as those exemplified as the substituent optionally having the phenylene group or the like of the compound (1).

Among the compounds (2), the compounds represented by any one of the following formulas (2-1) to (2-6) are preferable.

In the above formulas (2-1) to (2-6)

B ^{1 to} B ²⁰ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, a nitro group, a substituted or unsubstituted amino group (defined as a substituted amino group and an unsubstituted amino group) A chlorine atom or a trifluoromethyl group.

n1 to n4 independently represent an integer of 0 to 3;

When n1 is 2 or more, a plurality of B &lt; ^{2 &gt;} may be the same or different,

When n2 is 2 or more, a plurality of B &lt; ⁶ &gt; may be the same or different,

When n3 is 2 or more, a plurality of B &lt; ⁹ &gt; may be the same or different,

When n4 is 2 or more, the plural B &lt; ¹⁴ &gt; may be the same or different.

Such azo dyes may be those readily available on the market. Commercially available azo dyes that can be used for the composition for forming a polarizing layer include "NKX2029" and "G205" (manufactured by Hayashibara Seibutsukagaku Kagaku Sho).

The anthraquinone dye is preferably a compound represented by the formula (2-7).

In the above formula (2-7)

R ¹ to R ⁸ independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x, or a halogen atom.

R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms.

The acridine dye is preferably a compound represented by the formula (2-8).

In the above formula (2-8)

R ⁹ to R ¹⁵ independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x, or a halogen atom.

R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms.

As the oxazone dye, a compound represented by the general formula (2-9) is preferable.

In the above formula (2-9)

R ¹⁶ to R ²³ independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x, or a halogen atom.

R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms.

In the above formulas (2-7), (2-8) and (2-9), the alkyl group having 1 to 4 carbon atoms represented by R ^x is a methyl group, an ethyl group, a propyl group, Examples of the aryl group of 12 include a phenyl group, a toluyl group, a xylyl group and a naphthyl group.

As the cyanine dye, the compound represented by the formula (2-10) and the compound represented by the formula (2-11) are preferable.

In the above formula (2-10)

D ¹ and D ² independently represent a group represented by any one of formulas (2-10a) to (2-10d).

n5 represents an integer of 1 to 3;

In the above formula (2-11)

D ³ and D ⁴ independently represent a group represented by any one of formulas (2-11a) to (2-11h).

n6 represents an integer of 1 to 3;

The content of the dichroic dye in the composition for forming a polarizing layer may be appropriately adjusted depending on the kind of the dichroic dye or the like. For example, the content of the dichroic dye may be 0.1 part by mass or more and 50 parts by mass Or less, more preferably 0.1 parts by mass or more and 20 parts by mass or less, and still more preferably 0.1 parts by mass or more and 10 parts by mass or less. When the content of the dichroic dye is within this range, the above-mentioned polymerizable liquid crystal compound can be polymerized while keeping the alignment of the polymerizable liquid crystal compound without disturbing the liquid crystal state of the high-order smectic phase. If the content of the dichroic dye is too large, there is a fear that the orientation of the polymerizable liquid crystal compound is inhibited. Therefore, the content of the dichroic dye may be determined within a range in which the polymerizable liquid crystal compound can maintain a high-order smectic phase liquid crystal state.

The composition for forming a polarizing layer contains a solvent. This solvent can be suitably selected in consideration of the solubility and the like of the polymerizable liquid crystal compound to be used. However, it is preferable that the polymerizable liquid crystal compound is an inert solvent which does not disturb the progress of the polymerization reaction remarkably. Examples of such a solvent 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; Ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate,? -Butyrolactone, 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; Aromatic hydrocarbon solvents such as toluene and xylene; Nitrile solvents such as acetonitrile; Ether solvents such as tetrahydrofuran and dimethoxyethane; Chlorine-containing solvents such as chloroform and chlorobenzene, and the like. These solvents may be used alone or in combination of plural kinds.

The content of the solvent is preferably from 50 to 98% by mass based on the total amount of the composition for forming a polarizing layer. In other words, the solid content in the composition for forming a polarizing layer is preferably from 2 to 50 mass%. When the solid content is 2% by mass or more, dichroism required for the polarizing layer of the present polarizer can be obtained. On the other hand, when the solid content is 50% by mass or less, the viscosity of the composition for forming a polarizing layer is lowered, so that the thickness of the polarizing layer becomes almost uniform, and the polarizing layer tends not to be easily unevenly formed. Such a solid content can be determined by forming the thickness of the polarizing layer described above.

The composition for forming a polarizing layer contains a polymerization initiator. The polymerization initiator is preferably a photopolymerization initiator in that the polymerization reaction can be started under a lower temperature condition as a compound capable of initiating polymerization reaction of the polymerizable liquid crystal compound. Specifically, a compound capable of generating an active radical or an acid by the action of light under the condition of a low temperature (the low temperature refers to a temperature of 70 DEG C or lower, preferably 60 DEG C or lower as described above) is used as a photopolymerization initiator do. Among these photopolymerization initiators, it is more preferable that radicals are generated by the action of light.

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

Specific examples of the photopolymerization initiator are described below.

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'-methyldiphenylsulfide, 3,3 ', 4,4'- Peroxycarbonyl) benzophenone and 2,4,6-trimethylbenzophenone.

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

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) (4-methoxynaphthyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (Trichloromethyl) -6- [2- (5-methylfuran-2-yl) ethenyl] -1,3,5-triazine, 2,4-bis - [2- (furan-2-yl) ethenyl] -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2- ) Ethenyl] -1,3,5-triazine and 2,4-bis (trichloromethyl) -6- [2- (3,4-dimethoxyphenyl) ethenyl] -1,3,5-tri Azine, and the like.

As the photopolymerization initiator, those readily available on the market may be used. Examples of commercially available photopolymerization initiators include Irgacure 907, Irgacure 184, Irgacure 651, Irgacure 819, Irgacure 250, Irgacure 369 [Chiba Japan week)]; "Seake All BZ", "Seake All Z", "Seake All BEE" [Seiko Kagaku Co., Ltd.]; "Kayacure BP100" [Nippon Kayaku Co., Ltd.]; "Kayacure UVI-6992" (manufactured by Daiso); "Adeka Optomer SP-152 "," Adeka Optomer SP-170 " "TAZ-A "," TAZ-PP "(Nippon Shibel Hegner); And "TAZ-104" (manufactured by Sanwa Chemical Co., Ltd.).

The content of the polymerization initiator in the composition for forming a polarizing layer can be appropriately adjusted according to the kind and amount of the polymerizable liquid crystal compound contained in the composition for forming a polarizing layer, The content of the polymerization initiator in the mass part is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and still more preferably 0.5 to 8 parts by mass. When the content of the polymerizable initiator is within the above range, the alignment of the polymerizable liquid crystal compound can be polymerized without clogging, so that the polymerizable liquid crystal compound can be polymerized while maintaining a liquid state of a high-order smectic phase.

When the composition for forming a polarizing layer contains a photopolymerization initiator, the composition for forming a polarizing layer may contain a photosensitizer. Examples of the photosensitizer include xanthene compounds such as xanthone and thioxanthone (e.g., 2,4-diethylthioxanthone, 2-isopropylthioxanthone, etc.); Anthracene compounds such as anthracene and alkoxy group-containing anthracene (e.g., dibutoxyanthracene); Phenothiazine, rubrene, and the like.

When the composition for forming a polarizing layer contains a photopolymerization initiator and a photosensitizer, the polymerization reaction of the polymerizable liquid crystal compound contained in the composition for forming a polarizing layer can be further promoted. The amount of such a photosensitizer to be used can be appropriately adjusted depending on the kind and amount of the photopolymerization initiator and the polymerizable liquid crystal compound used in combination. For example, it is preferably 0.1 to 30 parts by mass per 100 parts by mass of the total amount of the polymerizable liquid crystal compound More preferably 0.5 to 10 parts by mass, still more preferably 0.5 to 8 parts by mass.

It has been described that the polymerization reaction of the polymerizable liquid crystal compound can be promoted by containing a photosensitizer in the composition for forming a polarizing layer. However, in order to stably proceed the polymerization reaction, May be appropriately contained. By containing the polymerization inhibitor, the progress of the polymerization reaction of the polymerizable liquid crystal compound can be controlled.

Examples of the polymerization inhibitor include hydroquinone, alkoxy group-containing hydroquinone, alkoxy group-containing catechol (e.g., butyl catechol), pyrogallol, 2,2,6,6-tetramethyl-1-piperidinyloxy radical Radical supplements; Thiophenols; β-naphthyl amines, β-naphthols, and the like.

When the composition for forming a polarizing layer contains a polymerization inhibitor, the content thereof can be appropriately controlled depending on the kind and amount of the polymerizable liquid crystal compound to be used, the amount of the photosensitizer, and the like. For example, the content of the polymerization inhibitor in the total amount of 100 parts by mass of the polymerizable liquid crystal compound is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and still more preferably 0.5 to 8 parts by mass. If the content of the polymerization inhibitor is within the above range, the alignment of the polymerizable liquid crystal compound or the polymerizable liquid crystal composition contained in the composition for polarizing layer formation can be polymerized without clogging, The liquid crystal composition can be polymerized while maintaining a liquid crystal state of a high-order smectic state satisfactorily.

The composition for forming a polarizing layer described above is applied on an alignment layer of a laminate having a transparent substrate and an alignment layer to obtain a first coated film and the polymerizable liquid crystal compound contained in the first coated film is polymerized The first dried film is formed by drying.

Examples of the method (application method) of applying the composition for forming a polarizing layer to the laminate include extrusion coating method, direct gravure coating method, reverse gravure coating method, CAP coating method, die coating method, dip coating method, And a spin coat method. These coating methods can also be applied when a composition for forming an orientation layer is applied onto a transparent substrate. The coating conditions are set so that the thickness of the obtained polarizing layer is in the preferable range described above.

Subsequently, by drying the first coating film, the solvent is removed from the first coating film, and the first dried coating film is formed. At the time of removing the solvent, volatile components other than the solvent contained in the first coating film are also removed. The drying method (drying method) is usually used for removing the solvent, and it can be carried out by a natural drying method, a ventilation drying method or a reduced pressure drying method, or a combination thereof. Any of the drying methods may be used, but drying conditions are preferably set so that the polymerizable liquid crystal compound contained in the first coating film is not polymerized.

&Lt; Process (3) >

In the step (3), the polymerizable liquid crystal compound is polymerized while maintaining the liquid crystal state of the polymerizable liquid crystal composition contained in the first dried film in the smectic liquid crystal state, whereby the polarizing layer .

&Lt; Formation of polarizing layer &

In order to make the liquid crystal state of the polymerizable liquid crystal compound contained in the first dried coating film a smectic phase (hereinafter, sometimes referred to as "smectic phase" or "smectic liquid crystal state"), It may be heated to a suitable temperature obtained from the phase transition temperature. In other words, the laminated sheet having the first dried film may be heated to a suitable temperature determined from the phase transition temperature. In forming the smectic phase, once the liquid crystalline state of the polymerizable liquid crystal compound contained in the first dried film is changed to a nematic phase (nematic liquid crystal state), the nematic phase is transferred to the smectic phase . In order to form the smectic phase via the nematic phase as described above, for example, the polymerizable liquid crystal compound contained in the first dried coating is heated to a temperature above the phase transition to the nematic liquid crystal state, and then the polymerizable liquid crystal compound And the temperature is cooled to a temperature representing a liquid crystal state on a smectic state.

In order to form a liquid crystal state of a smectic state via the nematic phase, the composition for forming a polarizing layer is particularly preferable when it contains the above-described leveling agent. When the leveling agent is contained in the first dried film when the liquid crystal state is formed, the leveling agent tends to flow in the first dried film, and the advantage that the polymerizable liquid crystal compound or the polymerizable liquid crystal composition is easily aligned horizontally have. The temperature for forming the nematic phase and the smectic phase is preferably in the range of not less than the nematic phase transition point and not more than the temperature higher than the nematic phase transition point by 100 DEG C and more preferably not more than the nematic phase transition point, A range of high temperature or lower is more preferable. The heat treatment for aligning the desired liquid crystal phase and the drying treatment for the solvent may be performed at the same time.

To polymerize the polymerizable liquid crystal compound, a polymerizable liquid crystal mixture comprising two or more polymerizable liquid crystal compounds (more preferably two kinds of polymerizable liquid crystal compounds A polymerizable liquid crystal mixture composed of the above-mentioned polymerizable smectic liquid crystal compound) is preferably used. When the composition for forming a polarizing layer in which the content ratio of each polymerizable liquid crystal compound in the polymerizable liquid crystal composition is adjusted is used, a liquid crystal state is formed in a smectic phase via a nematic phase, And there is an advantage that it is easy to easily maintain the liquid crystal state of the higher order smectic.

Here, a photopolymerization initiator is contained in the composition for forming a polarizing layer, the liquid crystalline state of the polymerizable liquid crystal compound in the first dried film is made to be a smectic phase, and the polymerizable liquid crystal compound The method of photopolymerizing a compound will be described in detail. In the photopolymerization, the light rays irradiating the first dried coating film include a kind of the photopolymerization initiator or the type of the polymerizable liquid crystal compound contained in the first dried film (in particular, the type of the photopolymerizable compound of the polymerizable liquid crystal compound) and And can be appropriately performed by light or active electron rays selected from the group consisting of visible light, ultraviolet light, and laser light according to the amount. Of these, ultraviolet light is preferred because it is easy to control the progress of the polymerization reaction, and since it can be used as a device for photopolymerization widely used in the art. Therefore, it is preferable that the kind of the polymerizable liquid crystal compound and the photopolymerization initiator contained in the composition for forming a polarizing layer is selected so that light can be cured by ultraviolet light. Further, in the polymerization, the polymerization temperature may be controlled by cooling the first dried film by an appropriate cooling means together with ultraviolet light irradiation. If the polymerization of the polymerizable liquid crystal compound can be carried out at a lower temperature by employing such a cooling means, even if the above-mentioned transparent substrate and orientation layer are relatively low in heat resistance, the advantage of being able to form a polarizing layer appropriately have. In the case of photopolymerization, a patterned polarizing layer can also be obtained by masking or developing.

By performing the above-mentioned photopolymerization, the polymerizable liquid crystal compound is polymerized in a smectic phase, preferably, while maintaining a liquid phase state of a high-order smectic phase as already exemplified, to form a polarizing layer. The polarizing layer obtained by polymerizing the polymerizable liquid crystal compound or the polymerizable liquid crystal composition while maintaining the state of liquid crystal state of the stymatic state can be a conventional polarizing layer, that is, a polymerizable liquid crystal compound or the like while maintaining the nematic phase liquid crystal state There is an advantage that the polarization performance is much higher than that of the polarizing layer obtained by polymerization.

The polarizing layer formed in this way is particularly preferable as long as it can obtain a black peak in X-ray diffraction measurement. As the polarizing layer from which such a black peak can be obtained, for example, there can be mentioned a polarizing layer showing a diffraction peak derived from a hexatellite phase or a crystal. The measurement conditions for such X-ray diffraction measurement are, for example, the conditions described in the examples of the present application.

&Lt; Process (4) >

The step (4) is a step of forming a protective layer on the polarizing layer of the laminated plate obtained by the step (3) and provided with an orientation layer and a polarizing layer in this order on a transparent substrate. When the polarizing layer of the present polarizer is a polarizing layer formed by polymerizing a polymerizable liquid crystal compound in a higher-order smectic liquid crystal state such as, for example, a smectic B phase, It may be altered by a factor. By forming a protective layer on the polarizing layer, deterioration of such polarizing layer can be very effectively prevented.

As the step (4)

A composition 1 for forming a protective layer containing a polyfunctional acrylate and a solvent is applied on the polarizing layer formed in the step (3) to form a second coating film on the polarizing layer, and the second coating film (4-1) forming a protective layer from the second coating film by polymerizing the polyfunctional acrylate contained in the step

A protective layer forming composition 2 containing a polymer or oligomer obtained by polymerizing a polyfunctional acrylate and water is applied on the polarizing layer formed in the step (3) to form a second coating film on the polarizing layer , A step (4-2) of forming a protective layer from the second coating film by drying the second coating film, and

A protective layer forming composition 3 containing a water-soluble polymer and water is applied onto the polarizing layer formed in the step (3) to form a second coating film on the polarizing layer, and the second coating film is dried, Step (4-3) of forming a protective layer from the second coating film,

And the like.

A composition 1 for forming a protective layer containing a polyfunctional acrylate and a solvent is applied on the polarizing layer formed in the step (3) to form a second coating film on the polarizing layer, and the second coating film A method of forming a protective layer from the second coating film by polymerizing the above-mentioned polyfunctional acrylate will be described. The method of forming the protective layer from the composition 1 for forming a protective layer has an advantage that the operation is very simple.

&Lt; Protective layer forming composition 1 >

The protective layer forming composition 1 contains a polyfunctional acrylate and a solvent. The polyfunctional acrylate contained in the composition 1 for forming a protective layer is preferably a group consisting of an acrylate group (CH ₂ ═CH-CO-) and a methacrylate group (CH ₂ ═C (CH ₃ ) -CO-) Means a compound having two or more groups selected in the molecule and having no liquid crystalline property like the compound (1). Preferable polyfunctional acrylates are compounds having 2 to 6 groups selected from the group consisting of an acrylate group and a methacrylate group in a molecule. Further, a polyfunctional acrylate or the like having two such groups may be referred to as &quot; bifunctional acrylate &quot; or the like hereinafter depending on the number of these groups, and a polyfunctional acrylate having three or more such groups may be referred to as &quot; Functional acrylate &quot;

When the polyfunctional acrylate contained in the composition 1 for forming a protective layer is used as a protective layer by curing and reacting the polyfunctional acrylate, the transparency such that the protective layer can transmit light, particularly visible light, Is selected. The term "transparency to the extent that visible light can be transmitted" has the same meaning as that described for the transparency of the transparent substrate.

Here, preferred multifunctional acrylates are exemplified.

Examples of bifunctional acrylates having two groups in the molecule selected from the group consisting of an acrylate group and a methacrylate group include 1,3-butanediol di (meth) acrylate; 1,3-butanediol (meth) acrylate; 1,6-hexanediol di (meth) acrylate; Ethylene glycol di (meth) acrylate; Diethylene glycol di (meth) acrylate; Neopentyl glycol di (meth) acrylate; Triethylene glycol di (meth) acrylate; Tetraethylene glycol di (meth) acrylate; Polyethylene glycol diacrylate; Bis (acryloyloxyethyl) ether of bisphenol A; Ethoxylated bisphenol A di (meth) acrylate; Propoxylated neopentyl glycol di (meth) acrylate; Ethoxylated neopentyl glycol di (meth) acrylate and 3-methylpentanediol di (meth) acrylate.

As the multifunctional acrylate having three or more functional groups and having six or less groups selected from the group consisting of an acrylate group and a methacrylate group in the molecule,

Trimethylolpropane tri (meth) acrylate; Pentaerythritol tri (meth) acrylate; Tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate; Ethoxylated trimethylolpropane tri (meth) acrylate; Propoxylated trimethylolpropane tri (meth) acrylate; Pentaerythritol tetra (meth) acrylate; Dipentaerythritol penta (meth) acrylate; Dipentaerythritol hexa (meth) acrylate; Tripentaerythritol tetra (meth) acrylate; Tripentaerythritol penta (meth) acrylate; Tripentaerythritol hexa (meth) acrylate; Tripentaerythritol hepta (meth) acrylate; Tripentaerythritol octa (meth) acrylate;

A reaction product of pentaerythritol tri (meth) acrylate and an acid anhydride; A reaction product of dipentaerythritol penta (meth) acrylate and an acid anhydride;

A reaction product of tripentaerythritol hepta (meth) acrylate and an acid anhydride;

Caprolactone-modified trimethylolpropane tri (meth) acrylate; Caprolactone-modified pentaerythritol tri (meth) acrylate; Caprolactone modified tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate; Caprolactone-modified pentaerythritol tetra (meth) acrylate; Caprolactone-modified dipentaerythritol penta (meth) acrylate; Caprolactone-modified dipentaerythritol hexa (meth) acrylate; Caprolactone-modified tripentaerythritol tetra (meth) acrylate; Caprolactone-modified tripentaerythritol penta (meth) acrylate; Caprolactone-modified tripentaerythritol hexa (meth) acrylate; Caprolactone-modified tripentaerythritol hepta (meth) acrylate; Caprolactone-modified tripentaerythritol octa (meth) acrylate; A reaction product of caprolactone-modified pentaerythritol tri (meth) acrylate and an acid anhydride; A reaction product of caprolactone-modified dipentaerythritol penta (meth) acrylate and an acid anhydride, and caprolactone-modified tripentaerythritol hepta (meth) acrylate and acid anhydride. Further, in the specific examples of the polyfunctional acrylate shown here, (meth) acrylate means acrylate or methacrylate. Further, caprolactone denaturation means that a caprolactone ring or ring opening polymer is introduced between the alcohol-derived site of the (meth) acrylate compound and the (meth) acryloyloxy group.

In order to obtain a protective layer having a large surface hardness, it is preferable to use a polyfunctional acrylate having three or more functional groups, and particularly preferably a functional acrylate, among the specific examples of the above-mentioned polyfunctional acrylate. The protective layer forming composition 1 may contain one kind of polyfunctional acrylate or may contain a plurality of kinds of polyfunctional acrylates.

In view of the printability of the protective layer forming composition 1 and the tackiness of the obtained protective layer, the protective layer forming composition 1 may contain a binder resin.

Examples of the binder resin include copolymers of at least one monomer selected from the group consisting of an unsaturated carboxylic acid and an unsaturated carboxylic acid anhydride and other monomers copolymerizable with the monomer.

Specific examples of the unsaturated carboxylic acid include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; Unsaturated dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid and itaconic acid; (Meth) acryloyloxyalkyl (meth) acrylate of a divalent or higher polyvalent carboxylic acid such as mono [2- (meth) acryloyloxyethyl] succinate and mono [2- (meth) acryloyloxyethyl] ] Esters; and unsaturated acrylates containing a hydroxyl group and a carboxyl group in the same molecule such as? - (hydroxymethyl) acrylic acid. The unsaturated carboxylic acid anhydride corresponds to an anhydride of the unsaturated carboxylic acid shown here. Among them, acrylic acid, methacrylic acid and maleic anhydride are preferable as the monomer for producing the binder resin. These acrylic acid, methacrylic acid and maleic anhydride are preferably used because they have good polymerization reactivity when copolymerized with various other monomers, have high glass transition temperature (Tg) and mechanical properties of the resulting binder resin, and are not tacky . In producing the binder resin, monomers selected from the group consisting of an unsaturated carboxylic acid and an unsaturated carboxylic acid anhydride may be used alone or in combination of two or more.

As the other monomer copolymerizable with the monomer selected from the group consisting of unsaturated carboxylic acid and unsaturated carboxylic acid anhydride,

Acrylic acid alkyl ester such as methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, sec-butyl (meth) acrylate and tert-butyl (meth) acrylate;

Cyclohexyl (meth) acrylate, 2-methylcyclohexyl (meth) acrylate, tricyclo [5.2.1.02,6] decan-8-yl (meth) acrylate (in the technical field, dicyclopentanyl (Meth) acrylate), dicyclopentanyloxyethyl (meth) acrylate, and isobornyl (meth) acrylate;

Cyclohexyl acrylate, 2-methylcyclohexyl acrylate, tricyclo [5.2.1.02,6] decan-8-yl acrylate (referred to in the art as dicyclopentanyl acrylate), dicyclopentoxy Acrylic acid cyclic alkyl esters such as ethyl acrylate and isobornyl acrylate;

(Meth) acrylic acid aryl esters such as phenyl (meth) acrylate and benzyl (meth) acrylate;

Dicarboxylic acid diesters such as diethyl maleate, diethyl fumarate and diethyl itaconate;

Hydroxyalkyl esters such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate;

2-ene, 5-ethylbicyclo [2.2.1] hept-2-ene, 2.2.1] hept-2-ene, 5-carboxybicyclo [2.2.1] hept-2-ene, 5-hydroxymethylbicyclo [2.2.1] 2.2.1] hept-2-ene, 5-ethoxybicyclo [2.2.1] , 5,6-dihydroxybicyclo [2.2.1] hepto-2-ene, 5,6-dicarboxybicyclo [2.2.1] hepto- 2,6-di (2'-hydroxyethyl) bicyclo [2.2.1] hept-2-ene, 5,6-dimethoxybicyclo [2.2. 2,1] hept-2-ene, 5,6-diethoxybicyclo [2.2.1] 2.2.1] hept-2-ene, 5-carboxy-5-ethylbicyclo [2.2 1] hept-2-ene, 5-hydroxymethyl-5-methylbicyclo [2 2,1] hept-2-ene, 5-carboxy-6-methylbicyclo [2.2.1] , 5-tert-butoxycarbonylbicyclo [2.2.1] hepto-2-ene, 5-cyclohexyloxine (5-tert-butoxycarbonylbicyclo [2.2.1] hept- 2,6-di (tert-butoxycarbonyl) bicyclo [2.2.1] hept-2-ene, 5-phenoxycarbonylbicyclo [2.2.1] 1] hept-2-ene and 5,6-di (cyclohexyloxycarbonyl) bicyclo [2.2.1] hepto-2-ene;

N-phenylmaleimide, N-cyclohexylmaleimide, N-benzylmaleimide, N-succinimidyl-3-maleimide benzoate, N-succinimidyl-4-maleimide butyrate, N- Dicarbonylimide derivatives such as N-succinimidyl-3-maleimidepropionate and N- (9-acridinyl) maleimide;

And examples thereof include styrene,? -Methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, p-methoxystyrene, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, acrylamide, methacrylamide, Vinyl, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene and the like.

Examples of the solvent contained in the protective layer forming composition 1 include those exemplified as the solvent contained in the above composition for forming a polarizing layer. Among them, the solvent contained in the composition 1 for forming a protective layer preferably contains a solvent selected from the group consisting of an alcohol solvent and an ether solvent, and more preferably consists essentially of an alcohol solvent and / or an ether solvent . Here, the &quot; solvent consisting substantially of an alcohol solvent and / or an ether solvent &quot; means that a solvent other than the above-mentioned alcohol solvent is scarcely contained, a solvent containing almost no solvent other than the above-mentioned ether solvent, And substantially no solvent other than the solvent is included. However, water or the like which is unintentionally contained in a solvent consisting substantially of an alcohol solvent and / or an ether solvent may be contained if it is a trace amount enough to form a protective layer. As described above, the alcohol solvent may include methanol, ethanol, butanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether. Examples of the ether solvent include ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate. Among them, ethanol, isopropyl alcohol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and a mixed solvent of a plurality of kinds selected from them are more preferable as the solvent contained in the composition for forming a polarizing layer.

When the composition contained in the protective layer forming composition 1 is substantially composed of an alcohol solvent and / or an ether solvent, when the protective layer forming composition 1 is applied on the polarizing layer, the alignment state of the polarizing layer is The protective layer can be formed while maintaining this alignment state so as not to be significantly damaged. In this regard, if the solvent contained in the protective layer forming composition 1 is substantially composed of an alcohol solvent and / or an ether solvent, the polarizer can be stably produced. In addition, the method of forming the protective layer using the composition 1 for forming a protective layer is advantageous in that the operation is simple. The content of the solvent contained in the composition 1 for forming a protective layer may be determined in consideration of the coating property when the composition 1 for forming the protective layer is applied on the polarizing layer. The content of the solvent is preferably from 10 to 80 parts by mass, more preferably from 20 to 60 parts by mass, based on 100 parts by mass of the total amount.

When the protective layer is formed from the composition 1 for forming a protective layer, it is necessary to polymerize and cure the polyfunctional acrylate contained in the protective layer forming composition 1. Also in the polymerization of the polyfunctional acrylate, the photopolymerization as described in the polymerization of the polymerizable liquid crystal compound contained in the composition for forming a polarizing layer is preferable. The photopolymerization of the polyfunctional acrylate can be carried out by irradiating visible light or ultraviolet rays to the second dried coating film formed on the polarizing layer by the protective layer forming composition 1. In order to efficiently perform photopolymerization of the polyfunctional acrylate, it is preferable that the composition for forming a protective layer 1 contains a photopolymerization initiator. Examples of the photopolymerization initiator include those exemplified as the photopolymerization initiator contained in the composition for forming a polarizing layer.

Hereinafter, the operation of forming the protective layer will be briefly described.

In order to form the protective layer, first, the protective layer forming composition 1 is applied on the polarizing layer to form a second coating film. The method of applying the composition 1 for forming a protective layer is the same as that described for the method of applying the composition for forming a polarizing layer, for example.

Next, a solvent (preferably an alcohol solvent and / or an ether solvent) is removed from the second coating film obtained by coating on the polarizing layer to obtain a second dried film. The same method as that exemplified as the drying method for forming the first dried coating film from the first coated film can be employed for such drying. In the process of drying the second dried film, it is necessary to prevent the unpolymerized polymerizable liquid crystal compound from being mixed into the second dried film during drying from the polarizing layer. The temperature condition for this is preferably in the range of about 0 캜 to 60 캜, and more preferably in the range of about 20 캜 to 50 캜. When the solvent contained in the protective layer forming composition 1 is a solvent described as being more preferable, the second coating film can be dried according to such suitable temperature conditions. Further, in order to perform drying in such a temperature range, the second coating film may be held under a suitable decompression condition depending on the kind of the solvent contained in the composition 1 for forming a protective layer.

The present inventors have found that when the composition 1 for forming a protective layer composed substantially of an alcohol solvent and / or an ether solvent as a solvent is applied on the polarizing layer, the properties of the polarizing layer are not impaired. Therefore, when the protective layer is formed on the polarizing layer by using the composition 1 for forming a protective layer, not only the protective layer can prevent the deterioration of the polarizing layer of the polarizer with time, It is possible to satisfactorily prevent the property of the polarizing layer from being deteriorated at the time of formation. Such an effect can not be immediately found in the production of a conventional polarizer, and is based on the unique knowledge of the present inventor.

A protective layer forming composition 2 containing a polymer or oligomer obtained by polymerizing a polyfunctional acrylate and water is applied on the polarizing layer formed in the step (3) to form a second coating film on the polarizing layer , And a method of forming the protective layer from the second coating film by drying the second coating film will be described. The method of forming the protective layer from the composition for forming a protective layer 2 has an advantage that the operation is very simple.

<Composition 2 for forming protective layer>

The protective layer forming composition 2 contains a polymer or an oligomer obtained by polymerizing a polyfunctional acrylate and water. Examples of the polymer or oligomer obtained by polymerizing the polyfunctional acrylate include aliphatic urethane acrylates and the like.

The content of water contained in the composition 2 for forming a protective layer may be determined in consideration of the coating property when the protective layer forming composition 2 is coated on the polarizing layer. For example, the total amount of the protective layer forming composition 2 , The content of water is preferably 50 to 99 parts by mass, more preferably 60 to 95 parts by mass.

Hereinafter, the operation of forming the protective layer will be briefly described.

In order to form the protective layer, first, the protective layer forming composition 2 is applied on the polarizing layer to form a second coating film. The method of applying the composition 2 for forming a protective layer is the same as that described above for the method of applying the composition for forming a polarizing layer, for example.

Next, water is removed from the second coating film to obtain a protective layer. This drying may be the same as the method of drying the first coating film. The temperature condition is preferably in the range of about 0 캜 to 100 캜, and more preferably in the range of about 20 캜 to 80 캜.

A protective layer forming composition 3 containing a water-soluble polymer and water is applied onto the polarizing layer formed in the step (3) to form a second coating film on the polarizing layer, and the second coating film is dried, A method of forming the protective layer from the second coating film will be described. The method of forming the protective layer from the composition for forming a protective layer has an advantage that the operation is very simple.

&Lt; Protective layer forming composition 3 >

The composition 3 for forming a protective layer contains a water-soluble polymer and water. Examples of the water-soluble polymer include polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinylpyrrolidone, pre-classified, methylcellulose, carboxymethylcellulose, sodium alginate and the like, preferably polyvinyl alcohol have.

The content of water contained in the composition 3 for forming a protective layer may be determined in consideration of the coating property when the composition 3 for forming the protective layer is applied on the polarizing layer. For example, the total amount of the protective composition 3 for forming a protective layer , The content of water is preferably 50 to 99 parts by mass, more preferably 60 to 95 parts by mass.

Hereinafter, the operation of forming the protective layer will be briefly described.

In order to form the protective layer, first, the protective layer forming composition 3 is applied on the polarizing layer to form a second coating film. The method of applying the composition 3 for forming a protective layer is the same as that described for the method of applying the composition for forming a polarizing layer, for example.

Next, water is removed from the second coating film to obtain a protective layer. This drying may be the same as the method of drying the first coating film. The temperature condition is preferably in the range of about 0 캜 to 100 캜, and more preferably in the range of about 20 캜 to 80 캜.

The thickness of the protective layer can be appropriately adjusted according to the type of the polarizing layer to be protected by the protective layer. For example, the thickness of the protective layer is preferably in the range of 0.1 mu m to 30 mu m, more preferably in the range of 1 mu m to 5 mu m. Such a thickness measurement may be the same as that described for the method of measuring the thickness of the polarizing layer.

<Polarizer>

The present polarizer obtained by the manufacturing method including the steps (1) to (4) is not only excellent in scratch resistance and solvent resistance on the surface of the polarizing layer, but also has heat resistance and humidity resistance It is more advantageous than the conventional polarizer. An embodiment of the present polarizing element manufacturing method including the steps (1) to (4) is characterized in that the first dried film of the step (3) is subjected to heat treatment at a temperature of 25 ± 10 ° C, The polymerizable liquid crystal compound or the polymerizable liquid crystal composition contained in the polymerizable liquid crystal composition can be modified in various ways without changing the mode of polymerization while maintaining the state of the stymatic liquid crystal. For example, when forming or preparing a laminate of the transparent substrate and the alignment layer in the step (1), the transparent substrate itself may have an orientation property, or a phase difference film may be further laminated in addition to the alignment layer, The polarizing layer, the retardation layer, and the protective layer may be provided in this order on the substrate. In addition, a bead-shaped resin having a refractive index different from that of the ultraviolet absorbing agent, the antistatic agent or the protective layer may be mixed into the protective layer formed in the step (4). However, since it is advantageous if the composition for forming the protective layer used in the formation of the protective layer is substantially composed of an alcohol solvent and / or an ether solvent as a solvent or water, the composition for forming the protective layer (4) can be carried out.

The present polarizer has been described above mainly in the form of a laminate of a transparent substrate / orientation layer / polarizing layer / protective layer, but other polarizing layers may be laminated on the polarizer. As described above, the present polarizer may further comprise a retardation film, or may further comprise an antireflection layer or a brightness enhancement film. Further, a circularly polarizing plate may be used in combination with a quarter wave plate. It is preferable that the 1/4 wavelength plate used when producing the circularly polarizing plate has such a characteristic that the in-plane retardation value for visible light becomes smaller as the wavelength becomes shorter.

&Lt; Use of Polarizer of Present Invention >

This polarizer can be used for various display devices. The display device is an apparatus having a display element, and includes a light emitting element or a light emitting element as a light emitting source. Examples of the display device include a liquid crystal display, an organic electroluminescence (EL) display, an inorganic electroluminescence (EL) display, an electron emission display (such as a full field emission display (FED) (Display device having a digital micromirror device (DMD)), an electronic paper (a display device using an electronic ink or an electrophoretic device, a plasma display device, a projection display device [e.g., a grating light valve (GLV) And a piezoelectric ceramic display. The liquid crystal display device includes all of a transmissive liquid crystal display device, a transflective liquid crystal display device, a reflection type liquid crystal display device, a direct viewing type liquid crystal display device and a projection type liquid crystal display device. The display device may be a display device for displaying a two-dimensional image or a stereoscopic display device for displaying a three-dimensional image.

This polarizer can be effectively used particularly in a display device of an organic electroluminescence (EL) display device or an inorganic electroluminescence (EL) display device in particular.

1 is a schematic view schematically showing the simplest cross-sectional configuration of the present polarizer. The alignment layer 3, the polarizing layer 4 and the protective layer 7 are laminated in this order from the transparent substrate 2 and the polarizing layer 4 is laminated on the matrix 5 in which the polymerizable liquid crystal compound is polymerized The dichroic dye 6 is dispersed.

Figs. 2 and 5 are schematic diagrams schematically showing the sectional configuration of a liquid crystal display (hereinafter referred to as &quot; present liquid crystal display &quot;) 10 using the polarizer. The liquid crystal layer 17 is sandwiched between the two substrates 14a and 14b.

Figs. 4 and 7 are schematic diagrams schematically showing the sectional configuration of an EL display device using the polarizer (hereinafter referred to as &quot; present EL display device &quot;

8 is a schematic view schematically showing a configuration of a projection type liquid crystal display device using the polarizer.

First, the liquid crystal display device shown in Fig. 2 will be described.

It is preferable that the polarizer is disposed on the light incidence side with respect to the liquid crystal layer. 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 with the liquid crystal layer 17 therebetween 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. Further, an overcoat layer (not shown) may be provided between the color filter 15 and the transparent electrode 16.

The thin film transistor 21 and the pixel electrode 22 are regularly arranged on the liquid crystal layer 17 side of the substrate 14b. The pixel electrode 22 is disposed at a position opposite to the color filter 15 with the liquid crystal layer 17 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.

As the substrate 14a and the substrate 14b, a glass substrate and a plastic substrate are used. Such a glass substrate or a plastic substrate may be made of the same material as that exemplified as the transparent substrate of the present polarizer. When a color filter 15 and a thin film transistor 21 to be formed on a substrate are manufactured, a glass substrate or a quartz substrate is preferable when a step of heating at a high temperature is required.

The thin film transistor can adopt an optimum one depending on 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 a glass substrate or an amorphous silicon transistor formed on a plastic substrate. In order to further miniaturize the 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. [ The liquid crystal layer 17 is provided with a spacer 23 for maintaining a constant distance between the substrate 14a and the substrate 14b. 2, the spacer is not limited to the columnar shape, and any shape can be used as long as the distance between the substrate 14a and the substrate 14b can be kept constant.

An alignment layer for aligning the liquid crystal in a desired direction may be disposed on a surface of the layer formed on the substrate 14a and the substrate 14b in contact with the liquid crystal layer 17. [ It is also possible to arrange the polarizer in the liquid crystal cell, that is, to place the polarizer in the surface side in contact with the liquid crystal layer 17. [ Such a format is hereinafter referred to as &quot; in-cell format &quot;. Details of this insole format will be described later.

Each member includes a substrate 14a, a color filter 15 and a black matrix 20, a transparent electrode 16, a liquid crystal layer 17, a pixel electrode 22, an interlayer insulating film 18, a thin film transistor 21, And a substrate 14b are stacked in this order.

A polarizer 12a and a polarizer 12b are provided outside the substrate 14b among the substrates 14a and 14b sandwiching the liquid crystal layer 17 and at least one of them is the polarizer 1).

It is also preferable that a retardation layer (for example, a 1/4 wavelength plate or an optical compensation film) 13a and 13b is laminated. By arranging the polarizer 12b out of the two polarizers, the liquid crystal display device 10 can be provided with a function of converting incident light into linearly polarized light. The retardation layer 13a and the retardation layer 13b do not need to be arranged depending on the structure of the liquid crystal display device and the type of the liquid crystal compound contained in the liquid crystal layer 17, And a polarizing film may be further provided on the light output side (outer side).

It is preferable that an antireflection film 11 for preventing reflection of external light is arranged on the outside of the polarizer 1 (on the outside of the polarizer 1 when the polarizer 1 is further provided).

As described above, the present polarizer 1 can be used for the polarizer 12a or the polarizer 12b of the present liquid crystal display 10 of Fig. The present polarizer 1 is provided in the polarizer 12a and / or the polarizer 12b, thereby achieving the effect of achieving a reduction in thickness of the liquid crystal display device 10. [

When the present polarizer 1 is used for the polarizer 12a or the polarizer 12b, the order of lamination is not particularly limited. This will be described with reference to enlarged views of portions A and B surrounded by a dotted line in Fig.

3 is an enlarged schematic sectional view of a portion A in Fig. 3A shows a case where the polarizer 1 is used as the polarizer 12a and the protective layer 7, the polarizing layer 4, the alignment layer 3 and the transparent substrate (not shown) from the retardation layer 13a side, 2) are arranged in this order. The polarizer 1 shown in Fig. 3 (A2) is a view showing a state in which the transparent substrate 2, the orientation layer 3, the polarizing layer 4 and the protective layer 7 are arranged in this order from the retardation layer 13a side, (1) is installed.

4 is an enlarged schematic view of a portion B in Fig. 4B2 shows a case where the protective layer 7, the polarizing layer 4, the alignment layer 3 and the transparent substrate 2 are formed from the retardation film 13b side when the present polarizer is used as the polarizer 12b. Are arranged in this order, the polarizer 1 is provided.

On the outside of the polarizer 12b, a backlight unit 19 which causes light emission is arranged. 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 an 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 polarizer can be selected according to the characteristics of the light source.

In the case where the liquid crystal display device 10 is a transmissive liquid crystal display device, the white light generated from the light source in the backlight unit 19 is incident on the light guide, and is changed by the reflection plate and diffused in the diffusion sheet. 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 unpolarized, only one of the linearly polarized lights transmits the polarizer 12b of the liquid crystal panel. The linearly polarized light is converted into circularly polarized light or elliptically polarized light by the phase difference layer 13b, and sequentially reaches the liquid crystal layer 17 through the substrate 14b, the pixel electrode 22, and the like.

The alignment state of the liquid crystal molecules contained in the liquid crystal layer 17 changes 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 to change the brightness of light emitted from the liquid crystal display device 10 Respectively. The polarized light passes through the liquid crystal layer 17 and the transparent electrode 16 and light of a certain wavelength range is transmitted through the color filter 15 Reaches the polarizer 12a and further passes through the antireflection film 11, the liquid crystal display displays the color determined by the color filter at the brightest.

Conversely, when the liquid crystal layer 17 is in an alignment state for transmitting and transmitting polarized light, 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 of these two states, since the brightness of light emitted from the liquid crystal display device 10 is also intermediate between the two, this pixel displays an intermediate color.

When the liquid crystal display device 10 is a transflective liquid crystal display device, it is preferable to use one obtained by further laminating a 1/4 wavelength plate on the protective layer side of the present polarizer. 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. On the other hand, in the reflection part, the external light is incident on the liquid crystal display device from the direction of the antireflection film 11, and the circularly polarized light transmitted through the present polarizer by the action of the 1/4 wave plate further provided on the present polarizer, And is reflected by the pixel electrode 22 and used for display.

Next, a suitable liquid crystal display device (this liquid crystal display device 24) of the in-cell type using the polarizer 1 will be described with reference to Fig.

In this liquid crystal display device 24, an antireflection film 11, a substrate 14a, a polarizer 12a, a phase difference layer 13a, a color filter 15 and a black matrix 20, a transparent electrode 16, The layer 17, the pixel electrode 22, the interlayer insulating film 18 and the thin film transistor 21, the retardation layer 13b, the polarizer 12b, the substrate 14b and the backlight unit 19 are stacked in this order, In this configuration, the polarizer 1 is preferably used as the polarizer 12a. In this configuration, the polarizer 1 is arranged in the order of the transparent substrate 2, the orientation layer 3, the polarizing layer 4, and the protective layer 7 from the antireflection film 11 side. In this liquid crystal display device 24 provided with the polarizer in this configuration, a function of converting incident light into linearly polarized light is given. The retardation layer 13a and the retardation layer 13b may not be arranged depending on the type of the liquid crystal compound included in the liquid crystal layer 17 as in the liquid crystal display device 10. [

Next, the EL display device using the polarizer will be described with reference to Figs. 4 and 7. Fig.

The EL display device 30 is formed by laminating the organic functional layer 36 and the cathode electrode 37 on the substrate 33 on which the pixel electrode 35 is formed. The retarder 32 and the polarizer 31 are disposed on the opposite side of the organic functional layer 36 with the substrate 33 interposed therebetween. The polarizer 1 is used as the polarizer 31. A positive voltage is applied to the pixel electrode 35 and a negative voltage is applied to the cathode electrode 37 to apply a direct current between the pixel electrode 35 and the cathode electrode 37 to cause the organic functional layer 36 to emit light. The organic functional layer 36 serving as a light emitting source is composed of an electron transporting layer, a light emitting layer, and a hole transporting layer. The light emitted from the organic functional layer 36 passes through the pixel electrode 35, the interlayer insulating film 34, the substrate 33, the retarder 32 and the polarizer 31 (the polarizer 1). Although the organic EL display device having the organic functional layer 36 is described, it may be applied to an inorganic EL display device having an inorganic functional layer.

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

Subsequently, a polarizer 31 (the present polarizer 1) is provided on the opposite side of the surface of the substrate 33 on which the thin film transistor 40 is provided. It is preferable to provide a retardation layer 32 between the polarizer 31 and the substrate 33. It is more preferable that the retardation layer 32 is formed of a quarter wavelength plate. In order to provide the retardation layer 32, a laminate 45 in which a polarizer 31 (the polarizer 1) and the retardation layer 32 are laminated in advance is prepared and the laminate 45 is laminated on the substrate 33 ). An outline of a manufacturing method using this layered product 45 is shown in Fig.

When the present polarizer 1 is used for the polarizer 31, the order of lamination is not particularly limited. This will be described with reference to an enlarged view of a portion C surrounded by a dotted line in Fig.

6 is an enlarged cross-sectional view schematically showing a portion C in Fig. 6C shows a state in which the transparent substrate 2, the alignment layer 3, the polarizing layer 4, and the protective layer 4 are formed from the retardation layer 32 side when the present polarizer 1 is used as the polarizer 31. [ (7) are arranged in this order, the polarizer 1 is provided. 6C is a plan view of the retardation film of the polarizer shown in FIG. 6C so that the protective layer 7, the polarizing layer 4, the alignment layer 3 and the transparent substrate 2 are arranged in this order from the retardation layer 32 side. 1) is installed.

Next, members other than the polarizer of the EL display device will be briefly described.

As the substrate 33, 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 and the like. Although not shown, a thermally conductive film may be formed on the substrate 33. Examples of the thermally conductive film include a diamond thin film (DLC, etc.). When the pixel electrode 35 is of a reflective type, light is emitted in a direction opposite to that of the substrate 33. Therefore, not only a transparent material but also a non-transparent material such as stainless can be used. The substrate may be formed as a single unit, or may be formed as a laminated substrate by bonding a plurality of substrates with an adhesive. In addition, these substrates are not limited to the plate type, and may be films.

As the thin film transistor 40, for example, a polycrystalline silicon transistor or the like may be used. The thin film transistor 40 is provided at the end of the pixel electrode 35 and has a size of about 10 to 30 mu m. The size of the pixel electrode 35 is about 20 탆 x 20 탆 to 300 탆 x 300 탆.

On the substrate 33, wiring electrodes of the thin film transistor 40 are provided. The wiring electrode has a low resistance and a function of electrically connecting to the pixel electrode 35 to suppress the resistance value. Generally, the wiring electrode is made of Al, Al, a transition metal (except for Ti), Ti Or titanium nitride (TiN) may be 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 depositing an inorganic material such as silicon oxide or silicon nitride such as SiO ₂ by sputtering or vacuum evaporation, a silicon oxide layer formed by SOG (spin-on-glass), a photoresist, A coating film of a resin material such as an acrylic resin, or the like.

And the ribs 41 are formed on the interlayer insulating film 34. The ribs 41 are arranged in the peripheral portion (between adjacent pixels) of the pixel electrode 35. [ As the material of the ribs 41, an acrylic resin, a polyimide resin and the like can be given. The thickness of the ribs 41 is preferably 1.0 mu m or more and 3.5 mu m or less, and more preferably 1.5 mu m or more and 2.5 mu m or less.

Next, an EL element including the pixel electrode 35 as a transparent electrode, the organic functional layer 36 as a light emitting source, and the cathode electrode 37 will be described. Each of the organic functional layers 36 has one or more hole transporting layers and light emitting layers and sequentially has, for example, an electron injection transporting layer, a light emitting layer, a hole transporting layer, and a hole injecting layer.

Examples of the pixel electrode 35 include ITO (indium tin oxide indium), IZO (indium zinc oxide indium), IGZO, ZnO, SnO ₂ and In ₂ O ₃ , but ITO and IZO are particularly preferable. The thickness of the pixel electrode 35 may have a thickness equal to or larger than a certain level sufficient for hole injection, and is preferably about 10 nm to 500 nm.

The pixel electrode 35 can be formed by a vapor deposition method (preferably a sputtering method). The sputter gas is not particularly limited, and inert gases such as Ar, He, Ne, Kr, and Xe, or a mixed gas thereof may be used.

Metal elements such as K, Li, Na, Mg, La, Ce, Ca, Sr, Ba, Al, Ag, In, Sn, Zn and Zr may be used as the constituent material of the cathode electrode 37, It is preferable to use a two-component or three-component alloy system selected from the exemplified metal elements. (Mg: 50 to 80 at%) and Al.Ca (Ca: Ca: Al: Ca: Al: Li: 0.3 to 14 at% 5 to 20 at%).

The cathode electrode 37 is formed by a vapor deposition method, a sputtering method, or the like. The thickness of the cathode electrode 37 is preferably 0.1 nm or more, and more preferably 1 nm to 500 nm or more.

The hole injection layer has a function of facilitating the injection of holes from the pixel electrode 35. The hole transport layer has a function of transporting holes and a function of interrupting electrons and is also called a charge injection layer or a charge transport layer.

The thickness of the light emitting layer, the sum of the hole injection layer and the hole transporting layer, and the thickness of the electron injection transporting layer are not particularly limited and are preferably 5 nm to 100 nm, although they vary depending on the forming method. Various organic compounds can be used for the hole injecting layer and the hole transporting layer. For the formation of the positive hole injection transport layer, the light emitting layer and the electron injection transport layer, a vacuum deposition method can be used in that a homogeneous thin film can be formed.

As the organic functional layer 36 serving as a light emitting source, it is possible to use light emission from a singlet exciton (fluorescence), use of light emitted from triplet excitons (phosphorescence), use of light emitted from singlet excitons (fluorescence) Including those using light emission (phosphorescence) from excitons, those formed with organic materials, those formed with organic materials and those formed with inorganic materials, polymer materials, low molecular materials, polymers and low molecular materials Can be used. However, the present invention is not limited to this, and the organic functional layer 36 using various known EL devices 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 weak in humidity. And the moisture is absorbed by the desiccant 38 to prevent deterioration of the organic functional layer 36.

8 is a schematic view showing a cross-sectional configuration of another embodiment of the present EL display device 30. Fig. This EL display device 30 has an encapsulation structure using the thin film encapsulation film 41, and emitted light can also be obtained from the opposite side of the array substrate.

As the thin film sealing film 41, it is preferable to use a DLC film obtained by depositing DLC (diamond-like carbon) on a film of an electrolytic capacitor. The DLC film has a characteristic that the water permeability is very poor, and the moisture-proof performance is high. Alternatively, a DLC film or the like may be directly deposited on the surface of the cathode electrode 37. 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, there are provided a novel polarizer (the present polarizer) and a novel display device (the present liquid crystal display device and the present EL display device) provided with the present polarizer according to the present invention.

Finally, a projection type liquid crystal display device using the polarizer 1 will be described.

Fig. 8 is a schematic view showing a projection type liquid crystal display device using the polarizer 1. Fig.

The present polarizer 1 is used as the polarizing film 142 and / or the polarizing film 143 of the projection type liquid crystal display device.

The bundle of rays emitted from a light source (for example, a high-pressure mercury lamp) 111 serving as a light emitting source is first transferred to the first lens array 112, the second lens array 113, the polarization conversion element 114, The uniformity of the luminance and the polarization of the half-beam bundle cross-section are performed.

Concretely, the bundle of rays emitted from the light source 111 is divided into a plurality of minute bundles of rays by the first lens array 112 in which the 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 bundles of rays irradiates the entire three liquid crystal panels 140R, 140G, and 140B to be illuminated. The entire surface of the side surface becomes almost uniform in roughness.

The polarization conversion element 114 is constituted by a polarizing beam splitter array and is disposed between the second lens array 113 and the superimposing lens 115. Thereby converting the random polarized light from the light source into polarized light having a predetermined polarization direction in advance and reducing the loss of the light amount in the incident-side polarizer described later to improve the luminance of the screen.

As described above, the luminance uniformized and polarized light is sequentially reflected by the dichroic mirrors 121, 123, and 132 for separating into three primary colors of R, G, and B via the reflective mirror 122, Blue channels, and are incident on the liquid crystal panels 140R, 140G, and 140B, respectively.

The polarizer film 142 of the present invention is disposed on the incident side of the liquid crystal panels 140R, 140G, 140B and the polarizer film 143 of the present invention is disposed on the outgoing side.

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

The polarizer 1 is useful as a polarizing film having excellent durability in any of the blue channel, green channel and red channel by selecting the kind of dichroic dye suitable for the corresponding channel.

The optical image created by transmitting incident light at different transmittances for each pixel in accordance with the image data of the liquid crystal panels 140R, 140G, 140B is synthesized by the cross dichroic prism 150 and is projected by the projection lens 170 onto the screen 180 ).

Examples of the electronic paper include those represented by molecules such as optical anisotropy and dye molecule orientation, electrophoresis, particle migration, particle rotation, particle change, phase change, A coloring / phase change of an organic compound, a display by light absorption of a molecule, a display by a self-luminescence combined with an electron and a hole, and the like. More specifically, examples of the electrophoretic particles include microcapsules electrophoresis, horizontal transfer electrophoresis, vertical transfer electrophoresis, spherical twist ball, magnetic twist ball, circumferential twist ball method, charged toner, electron powder fluid, Electrowetting, light scattering (transparent / opaque change), cholesteric liquid crystal / photoconductive layer, cholesteric liquid crystal, bistable nematic liquid crystal, ferroelectric liquid crystal, dichroic dye / liquid crystal dispersion type, Photochromic, electrochromic, electrodeposition, flexible organic EL, and the like. The electronic paper may be used for advertisement display (signage) or the like as well as for personal use of text or images. According to the optical film of the present invention, the thickness of the electronic paper can be reduced.

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

Example

Hereinafter, the present invention will be described in more detail with reference to Examples. In the examples, &quot;% &quot; and &quot; part &quot; are parts by mass and parts by mass unless otherwise specified.

In the present embodiment, the following polymerizable liquid crystal compounds were used.

The compound (1-6) [compound represented by the following formula (1-6)

Compound (1-6) can be prepared according to Lub et al. Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996).

[Measurement of phase transition temperature]

The phase transition temperature of the compound (1-6) was confirmed by determining the phase transition temperature of the film composed of the compound (1-6). The operation is as follows.

A film composed of the compound (1-6) was formed on a glass substrate having an orientation film formed thereon and the phase transition temperature was confirmed by texture observation with a polarization microscope (BX-51, manufactured by Olympus) while heating. The film composed of the compound (1-6) was heated to 120 deg. C, phase-transformed to a nematic phase at 112 deg. C at the temperature lowering temperature, phase transitions to a smectic A phase at 110 deg. Phase transition.

The compound (1-7) [compound represented by the following formula (1-7)

Compound (1-7) was synthesized with reference to the synthesis of compound (1-6) described above.

[Measurement of phase transition temperature]

The phase transition temperature of the compound (1-7) was confirmed in the same manner as the phase transition temperature measurement of the compound (1-6). The compound (1-7) was heated to 140 ° C and then phase-transformed into a nematic phase at 133 ° C at the time of temperature lowering, phase-transition to a smectic A phase at 118 ° C, Respectively.

Example 1

[Preparation of Composition for Polarizing Layer]

The following components were mixed and stirred at 80 占 폚 for 1 hour to obtain a composition for forming a polarizing layer.

A polymerizable liquid crystal compound; The compound (1-6) 50 parts

Compound (1-7) 50 parts

Dichroic dye; Azo dye (NKX2029; manufactured by Hayashibara Seibutsukagaku Kenkou Sho) 2.5 parts

A polymerization initiator;

2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one (Irgacure 369; manufactured by Ciba Specialty Chemicals) Part 6

Leveling agents;

A polyacrylate compound (BYK-361N, manufactured by BYK-Chemie) 1.2 part

solvent; Cyclopentanone 250 parts

[Measurement of phase transition temperature]

As in the case of the compound (1-6) and the compound (1-7), the phase transition temperature of the polymerizable liquid crystal composition contained in the polarizing layer forming composition prepared as described above was determined. This polymerizable liquid crystal composition is a liquid crystal composition which undergoes a phase transition to a nematic phase at 112 ° C and a phase transition to a smectic A phase at 104 ° C and a phase transition to a smectic B phase at 78 ° C Respectively.

[Production and evaluation of polarizers]

1. Formation of orientation layer

A glass substrate was used as a transparent substrate.

A 2 mass% aqueous solution of polyvinyl alcohol (polyvinyl alcohol 1000 fully saponified type, manufactured by Wako Pure Chemical Industries, Ltd.) (composition for forming an orientation layer) was applied on the above glass substrate by a spin coat method and dried , A film having a thickness of 100 nm was formed. Subsequently, the surface of the obtained film was rubbed to form an alignment layer. The rubbing treatment was carried out with a cloth (trade name: YA-20-RW, manufactured by Yoshikawa Kako Co., Ltd.) using a semiautomatic rubbing apparatus (trade name: LQ-008 type, manufactured by JOYAKO KOGYO Co., Ltd.) , And the number of revolutions was 500 rpm and 16.7 mm / s. By this rubbing treatment, a layered product 1 having an orientation layer formed on a glass substrate was obtained.

2. Formation of polarizing layer

The composition for forming a polarizing layer was applied on the orientation layer of the layered product 1 by a spin coat method and heated and dried on a hot plate at 120 캜 for 3 minutes and then rapidly cooled to 70 캜 The temperature of the first dried film was lowered to a temperature lower than the temperature of the first dried film. In this first dried film, the liquid crystalline state of the polymerizable liquid crystal compound contained was a smectic B phase. Subsequently, ultraviolet rays were irradiated onto the first dried coating film with an exposure amount of 2400 mJ / cm 2 (based on 365 nm) using a UV irradiator (SPOT CURE SP-7, manufactured by Ushio DENKI K.K.) The polymerizable liquid crystal compound contained in the film was polymerized while maintaining the liquid crystal state of the polymerizable liquid crystal composition, and a polarizing layer was formed from the first dried film to obtain a layered product (2). The thickness of the polarizing layer at this time was measured by a laser microscope (OLS3000, manufactured by Olympus Corporation) and found to be 1.8 占 퐉.

3. X-ray diffraction measurement

X-ray diffraction measurement was performed on the polarizing layer of the obtained layered product (2) using an X-ray diffraction device X'Pert PRO MPD (manufactured by Parent Company). Using Cu as a target, X-rays generated under conditions of an X-ray tube current of 40 mA and an X-ray tube voltage of 45 kV were irradiated in a rubbing direction through a fixed diverging slit 1/2 ° (preliminarily obtaining the rubbing direction of the orientation layer under the polarizing layer ), And scanning was performed in the range of 2θ = 0.01671 ° in the range of the scanning range 2θ = 4.0 to 40.0 °. As a result, a sharp diffraction peak (FWHM) of about 0.187 ° was observed at 2θ = 20.22 ° Black peak) was obtained. In addition, the same results were obtained when incidence from the rubbing vertical direction. The ordering period (d) obtained from the peak position is about 4.39 Å, which indicates that the structure reflecting the high order smectic phase is formed.

4. Preparation of Polarizers by Protective Layer Formation

50 parts of dipentaerythritol hexaacrylate (ARONIX M-403, manufactured by Dojo Kasei K.K.), 50 parts of an acrylate resin (Ebecryl 4858 Diesell UCB Co., Ltd.) on the polarizing layer of the layered product (2) A solution of 3 parts of 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one (Irgacure 907; manufactured by Ciba Specialty Chemicals) in 250 parts of isopropanol (SPOT CURE SP-7, manufactured by Ushio Corporation) was applied by a spin coat method, and then dried by heating on a hot plate at 50 占 폚 for 1 minute, Was irradiated with an exposure amount of 400 mJ / cm 2 (based on 365 nm) to form a protective layer on the polarizing layer, to thereby produce this polarizer (hereinafter referred to as &quot; Polarizer A &quot;). The protective layer at this time was measured by a laser microscope (OLS3000, manufactured by Olympus Corporation) and found to be 2.8 mu m.

5. Measurement of dichroic ratio

In order to confirm the usability of the polarizer, the dichroic ratio was measured as follows.

The absorbance (A ¹ ) in the transmission axis direction at the maximum absorption wavelength and the absorbance (A ² ) in the absorption axis direction were set to a folder in which a polarizer was attached to a spectrophotometer (UV-3150 manufactured by Shimadzu Corporation) And measured by a double beam method using one apparatus. In this folder, the reference side was provided with a mesh that cuts the light amount by 50%. The ratio (A ² / A ¹ ) was calculated from the measured absorbance (A ¹ ) in the transmission axis direction and the absorbance (A ² ) in the absorption axis direction to obtain a dichroic ratio. The results are shown in the table. The higher the dichroic ratio, the more useful it is as a polarizing film. Table 1 shows the measurement results of the dichroic ratio.

Example 2

The same experiment as in Example 1 was carried out except that the dichroic dye was changed to an azo dye (G205; manufactured by Hayashibara Seibutsukagaku Kagaku Sho) in an azo dye (NKX2029; manufactured by Hayashibara Seibutsukagaku Kagyusho Co., Ltd.) Quot; Polarizer B &quot;). The phase transition behavior of the polymerizable liquid crystal composition at this time was such that the phase transition occurred in a nematic phase at 112 캜 and a phase transition to a smectic A phase at a temperature of 112 캜 after raising the temperature to 120 캜 at 77 캜, Phase transition. Table 1 shows the dichroism ratio measurement results of the obtained polarizers.

Example 3

The same polarizer (hereinafter referred to as &quot; Polarizer C &quot;) was produced in the same manner as in Example 1 except that the solvent contained in the composition for forming the protective layer was changed from isopropanol to ethanol. Table 1 shows the result of measuring the dichroic ratio of the prepared polarizer.

Example 4

The same polarizer (hereinafter referred to as &quot; Polarizer D &quot;) was produced in the same manner as in Example 1 except that the solvent contained in the composition for forming the protective layer was changed from isopropanol to propylene glycol monomethyl ether acetate. Table 1 shows the result of measuring the dichroic ratio of the prepared polarizer.

Example 5

The same polarizer (hereinafter referred to as &quot; present polarizer E &quot;) was produced in the same manner as in Example 1 except that the solvent contained in the composition for forming the protective layer was changed from isopropanol to propylene glycol monomethyl ether. Table 1 shows the result of measuring the dichroic ratio of the prepared polarizer.

Example 6

A TAC (triacetylcellulose) film was bonded to the protective layer of the polarizer A obtained in Example 1 through an adhesive layer formed of a pressure sensitive adhesive (PSA). Table 1 shows the dichroism ratio measurement result of the structure thus obtained (hereinafter referred to as &quot; Polarizer A + TAC &quot;).

Example 7

A TAC (triacetylcellulose) film was bonded to the protective layer of the polarizer B obtained in Example 2 through an adhesive layer formed of a pressure sensitive adhesive (PSA). Table 1 shows the result of dichroism measurement of the structure thus obtained (hereinafter referred to as &quot; Polarizer B + TAC &quot;).

Example 8

The surface was activated by corona treatment on the polarizing layer prepared in the same manner as in Example 1, and a 10 mass% aqueous solution of polyvinyl alcohol (polyvinyl alcohol 1000 completely saponified type, manufactured by Wako Pure Chemical Industries, Ltd.) Was applied by a spin coat method and heated and dried on a hot plate at 80 占 폚 for 1 minute to form a protective layer on this polarizing layer to prepare this polarizer (hereinafter referred to as &quot; Polarizer F &quot;). Table 1 shows the result of measuring the dichroic ratio of the prepared polarizer.

Example 9

The surface of the polarizing layer prepared in the same manner as in Example 1 was subjected to corona treatment to activate the surface, and a solution (UCECOAT7655, manufactured by Daicel-Cytek Chemical Co., Ltd.) in which the aliphatic urethane acrylate resin was dispersed was subjected to spin coating And heated and dried on a hot plate at 60 占 폚 for 1 minute to form a protective layer on this polarizing layer to prepare this polarizer (hereinafter referred to as &quot; Polarizer G &quot;). Table 1 shows the result of measuring the dichroic ratio of the prepared polarizer.

Example 10

A TAC (triacetylcellulose) film was bonded to the protective layer of the polarizer A obtained in Example 8 through an adhesive layer formed of a pressure sensitive adhesive (PSA). The dichroism ratio measurement result of the structure thus obtained (hereinafter referred to as &quot; polarizer F + TAC &quot;) is shown in Table 1.

Example 11

A TAC (triacetylcellulose) film was bonded to the protective layer of the polarizer A obtained in Example 9 through an adhesive layer formed of a pressure sensitive adhesive (PSA). The dichroic ratio measurement results of the thus obtained structure (hereinafter referred to as &quot; polarizer G + TAC &quot;) are shown in Table 1.

(※)

IPA: isopropanol

ETA: Ethanol

PGMEA: Propylene glycol monomethyl ether acetate

PGME: Propylene glycol monomethyl ether

Evaluation example

1. Durability test

As a durability test of the present polarizer, the following aging test was carried out.

The present polarizers obtained in Examples 1 and 2 and the structures (present polarizer A + TAC, present polarizer B + TAC or polarizers F + TAC) obtained in Examples 6 to 7 and 10 were placed in a Hitachi constant temperature bath (trade name: EC-15HHP, (Condition: dry bulb temperature 60 deg. C, humidity 90% RH, or 85 deg. C humidity 0%), and the absorbance after 100 hours was measured to obtain a dichroic ratio. The dichroic ratio was measured again after the lapse of 100 hours in this way. The case where the initial dichroic ratio and the case where the dichroic ratio after the elapsed time were hardly changed is indicated as "g" (good), and the case where the dichroic ratio after the lapse of time is "b" 2 level. The results are shown in Table 2.

2. Examination of ingredients

When the present polarizer is used in a liquid crystal cell, that is, in an in-cell type liquid crystal display, it is necessary to provide a PI (polyimide) orientation film on the protective layer of the polarizer. For the formation of the PI alignment film, an NMP (N-methyl-2-pyrrolidone) solution is often used. That is, this polarizer requires solvent resistance to NMP. Therefore, NMP was dropped onto the surfaces of these protective layers, and the protective layers were held for 5 minutes and then wiped off to evaluate whether or not the protective layers were dissolved. The evaluation result was judged to be two levels of "g" (good) when no dissolution was observed by NMP, and "b" (bad) when dissolution by NMP was observed. The results are shown in Table 3.

The polarizer of the present invention is very useful in manufacturing a liquid crystal display, an (organic) EL display, and a projection type liquid crystal display.

1: Polarizer (present polarizer) of the present invention
2: transparent substrate
3: orientation layer
4: polarizing layer
5: Matrix
6: Dichromatic dye
7: Protective layer
10: Liquid crystal display
11: Antireflection film
12a, 12b: Polarizing film
13a, 13b: retardation layer
14a and 14b:
15: Color filter
16: Transparent electrode
17: liquid crystal layer
18: Interlayer insulating film
19: Backlight unit
20: Black Matrix
21: Thin film transistor
22:
23: Spacer
24: Liquid crystal display
30: EL display device
31: Polarizer
32: retardation layer
33: substrate
34: Interlayer insulating film
35:
36: light emitting layer
37: cathode electrode
38: Desiccant
39: bag 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: superposing lens
121, 123, 132: Dichroic mirrors
122: reflection mirror
140R, 140G, 140B: a liquid crystal panel
142, 143: Polarizing film
150: Cross dichroic prism
170: projection lens
180: Screen

Claims (13)

A polarizer provided with an orientation layer, a polarizing layer and a protective layer in this order on a transparent substrate, and a laminate having an adhesive layer laminated on the protective layer,
Wherein the polarizing layer
A step of forming a film from a composition comprising a polymerizable liquid crystal compound, a dichroic dye, a polymerization initiator and a solvent;
Removing the solvent from the film,
A step of bringing the polymerizable liquid crystal compound contained in the film from which the solvent has been removed into a smectic liquid crystal state,
A step of polymerizing the polymerizable liquid crystal compound while maintaining the state of the smectic liquid crystal state
Lt; RTI ID = 0.0 &gt; 1, &lt; / RTI &gt; The laminate according to claim 1, wherein the polarizing layer is a polarizing layer in which a black peak is obtained in X-ray diffraction measurement. The laminate according to claim 1 or 2, wherein the thickness of the polarizing layer is in the range of 0.5 mu m to 3 mu m. The laminate according to claim 1 or 2, wherein the dichroic dye is an azo dye. The laminate according to claim 1 or 2, wherein the polymerizable liquid crystal compound comprises two or more polymerizable smectic liquid crystal compounds. The laminate according to claim 1 or 2, wherein the protective layer is formed from a protective layer composition comprising a polyfunctional acrylate and a solvent, and the solvent is substantially an alcohol solvent and / or an ether solvent. The laminate according to claim 1 or 2, wherein the protective layer is formed from a composition for forming a protective layer comprising a polymer or oligomer obtained by polymerizing a polyfunctional acrylate and water. The laminate according to claim 1 or 2, wherein the protective layer is formed from a composition for forming a protective layer comprising a water-soluble polymer and water. A liquid crystal display device comprising the laminate according to claim 1 or 2. The liquid crystal display device according to claim 9, wherein the laminate is disposed inside a liquid crystal cell. A circularly polarizing plate provided with a 1/4 wavelength plate on the pressure-sensitive adhesive layer of the laminate according to claim 1 or 2. 12. The circular polarizer according to claim 11, wherein the 1/4 wavelength plate is a wave plate having a characteristic in which an in-plane retardation value for visible light becomes smaller as a wavelength becomes shorter. An organic EL display device comprising the circularly polarizing plate according to claim 11 and an organic EL device.

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