JP2019194728A - Polarizer and method of manufacturing the same - Google Patents

Abstract

To provide a novel polarizer and a method of manufacturing the same.SOLUTION: A polarizer is provided, comprising an alignment layer, a polarizing layer, and a protective layer provided on a transparent base material in the described order. The polarizing layer is formed by polymerizing a polymerizable liquid crystal compound containing an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group, or an oxetanyl group as a polymerizable group, and dispersing a dichroic pigment in a matrix in a smectic liquid crystal state. The protective layer contains a water-soluble polymer.SELECTED DRAWING: Figure 1

Description

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

  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, in Patent Document 1, a transparent resin protective layer (protective film), a light absorption anisotropic layer (polarizing film), and a transparent film (transparent substrate) are laminated in this order on a transparent film (transparent substrate). A polarizer is described in which the light absorption anisotropic layer contains a dichroic dye having a specific structure and nematic liquid crystallinity.

JP 2010-152351 A

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

The present invention includes the following inventions [1] to [14].
[1] A polarizer in which an alignment layer, a polarizing layer and a protective layer are provided in this order on a transparent substrate,
The polarizing layer is
In a layer in which a dichroic dye is dispersed in a matrix in a smectic liquid crystal state obtained by polymerizing a polymerizable liquid crystal compound having an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group or an oxetanyl group as a polymerizable group. Yes,
The protective layer is a polarizer including a water-soluble polymer.
[2] The polarizer according to [1], wherein the polarizing layer is a polarizing layer from which a Bragg peak is obtained in X-ray diffraction measurement.
[3] The polarizer according to [1] or [2], wherein the polarizing layer has a thickness in the range of 0.5 to 3 μm.
[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 includes two or more polymerizable smectic liquid crystal compounds.
[6] 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.
[7] A liquid crystal display device in which the polarizer according to any one of [1] to [6] is disposed inside a liquid crystal cell.
[8] A circularly polarizing plate in which a quarter-wave plate is provided on the protective layer of the polarizer according to any one of [1] to [6].
[9] The circularly polarizing plate according to [8], wherein the quarter-wave plate is a wavelength plate having a characteristic that an in-plane retardation value with respect to visible light decreases as the wavelength decreases.
[10] An organic EL display device comprising the circularly polarizing plate according to [8] or [9] and an organic EL element.
[11] A step (1) of forming a laminate by providing an alignment layer on a transparent substrate;
A step (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 and forming a first coating film on the alignment layer; ,
The first coating film formed in the step (2) is dried under a condition in which the polymerizable liquid crystal compound contained in the first coating film is not polymerized to form a first dry film, and the first coating film is formed. A step of forming a polarizing layer from the first dry film by polymerizing the polymerizable liquid crystal compound while maintaining the smectic liquid crystal state after the polymerizable liquid crystal compound in the dry film is in a smectic liquid crystal state ( 3) and
On the polarizing layer formed in the step (3), a protective layer composition containing a water-soluble polymer and water is applied to form a second coating film on the polarizing layer, and the second coating is applied. And a step (4) of forming a protective layer from the second coating film by polymerizing the polyfunctional acrylate contained in the film.
[12] A step (1) of forming a laminate by providing an alignment layer on a transparent substrate;
A step (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 and forming a first coating film on the alignment layer; ,
The first coating film formed in the step (2) is dried under a condition in which the polymerizable liquid crystal compound contained in the first coating film is not polymerized to form a first dry film, and the first coating film is formed. A step of forming a polarizing layer from the first dry film by polymerizing the polymerizable liquid crystal compound while maintaining the smectic liquid crystal state after the polymerizable liquid crystal compound in the dry film is in a smectic liquid crystal state ( 3) and
On the polarizing layer formed in the step (3), a protective layer-forming composition containing a water-soluble polymer and water is applied to form a second coating film on the polarizing layer, (2) The manufacturing method of a polarizer which has a process (4) which forms a protective layer from this 2nd coating film by drying a coating film.

  According to the present invention, a novel polarizer is provided.

It is the schematic showing the cross-sectional structure of the polarizer of this invention typically. It is the schematic which represents typically the cross-sectional structure of the liquid crystal display device using the polarizer of this invention. It is the schematic which represents typically the layer order of the polarizer of this invention provided in the liquid crystal display device. It is the schematic which represents typically the layer order of the polarizer of this invention provided in the liquid crystal display device. It is the schematic which represents typically the cross-sectional structure of the liquid crystal display device (in-cell form) using the polarizer of this invention. It is the schematic which represents typically the cross-sectional structure of the EL display apparatus using the polarizer of this invention. It is the schematic which represents typically the manufacturing method of the EL display apparatus using the polarizer of this invention. It is the schematic which represents typically the layer order of the polarizer of this invention provided in EL display apparatus. It is the schematic which represents typically the cross-sectional structure of the EL display apparatus using the polarizer of this invention. It is the schematic which shows the projection type liquid crystal display device using the polarizer of this invention.

The polarizer of the present invention (hereinafter referred to as “the present polarizer” in some cases) is a transparent base material in which an alignment layer, a polarizing layer and a protective layer are provided in this order.
Forming a coating film from a composition containing 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 has been removed into a smectic liquid crystal state;
And the step of polymerizing the polymerizable liquid crystal compound while maintaining the smectic liquid crystal state.

A preferred embodiment of the method for producing the polarizer will be described with reference to the drawings as necessary. A preferred embodiment of the production method is:
A step (1) of forming a laminate by providing an alignment layer on a transparent substrate;
A composition containing a polymerizable liquid crystal compound, a dichroic dye and a polymerization initiator is applied on the alignment layer of the laminate formed in the step (1), and a first application is applied on the alignment layer. Forming a film (2);
The first coating film formed in the step (2) is dried under a condition in which the polymerizable liquid crystal compound contained in the first coating film is not polymerized to form a first dry film, and the first drying A step of forming a polarizing layer from the first dry film by polymerizing the polymerizable liquid crystal compound while maintaining the smectic liquid crystal state after the polymerizable liquid crystal compound in the film is in a smectic liquid crystal state (3) )When,
On the polarizing layer formed in the step (3), a protective layer composition containing a polyfunctional acrylate and a solvent is applied to form a second coating film on the polarizing layer, and the second coating film And (4) forming a protective layer from the second coating film by polymerizing the polyfunctional acrylate contained in the film. Hereinafter, this manufacturing method is demonstrated for every process.

<Transparent substrate>
In the manufacturing method of this polarizer, first, a transparent substrate is prepared. The transparent substrate is a substrate having transparency to the extent that light, particularly visible light can be transmitted. The transparency refers to a characteristic that the transmittance with respect to a light beam having a wavelength of 380 to 780 nm is 80% or more. Specific examples of such transparent substrates include glass substrates, plastic translucent sheets, and translucent films. Examples of the plastic constituting the translucent sheet or translucent film include polyolefins such as polyethylene, polypropylene and norbornene polymers; cyclic olefin resins; polyvinyl alcohol; polyethylene terephthalate; polymethacrylates; Acid esters; cellulose esters such as triacetyl cellulose, diacetyl cellulose and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyether sulfone; polyether ketone; polyphenylene sulfide and polyphenylene oxide. Among the specific examples of the transparent substrate described above, among the plastic translucent sheet and translucent film, a plastic translucent film, that is, a polymer film is preferable. Among the polymer films, a polymer film made of cellulose ester or a cyclic olefin resin (cellulose ester film or cyclic olefin resin film) from the viewpoint that it can be easily obtained from the market or has excellent transparency. Is preferred. In manufacturing the present polarizer using such a transparent substrate, the transparent substrate can be easily handled without causing damage such as tearing when the transparent substrate is transported or stored. A support base material or the like may be pasted. In addition, the thickness of this transparent base material should just be a grade which can express the above-mentioned transparency. Moreover, when using a polymer film as a transparent base material, you may provide the function as a phase difference film to the said polymer film by extending | stretching process etc. In addition, when providing the function as a retardation film to a transparent base material, it demonstrates later.

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

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

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

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

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

  When used as a transparent substrate, the thickness of the polymer film is preferably such that the weight is such that it can be handled practically and sufficient transparency can be ensured. Tends to be lowered and the processability tends to be inferior. Therefore, an appropriate thickness of these films is, for example, about 5 to 200 μm, and preferably 20 to 100 μm. When using this polarizer as a circularly-polarizing plate mentioned later, when using the display apparatus using the said circularly-polarizing plate for a mobile use, about 20-80 micrometers of film thickness is especially preferable. In addition, when giving retardation to a film by extending | stretching, the thickness after extending | stretching is determined by the thickness of the film before extending | stretching, and a draw ratio.

<Step (1)>
In step (1), by providing an alignment layer on the above-described transparent substrate, a laminate having a transparent substrate and an alignment layer, preferably a laminate in which the transparent substrate and the alignment layer are stacked, is formed. . When the transparent substrate is subjected to a surface treatment such as a hard coat treatment or an antiglare treatment, an alignment layer may be formed on the surface opposite to the surface treated surface.

<Alignment layer>
The alignment layer is preferably one that is not significantly modified in the process of forming the polarizing layer described later. As a method for forming the alignment layer, a method using an alignment polymer that can impart an alignment regulating force by rubbing (hereinafter referred to as “rubbing method” in some cases), an alignment regulating force can be imparted by irradiating polarized light. A method using a photo-alignable polymer (hereinafter sometimes referred to as “photo-alignment method”), a method of forming an alignment layer by obliquely depositing silicon oxide on a transparent substrate (transparent substrate surface), and Langmuir -A method of forming an alignment layer by forming a monomolecular film having a long-chain alkyl group using a blow jet method (LB method). Among these, the rubbing method and the photo-alignment method are preferable from the viewpoint of obtaining an alignment layer having excellent alignment uniformity and the processing time and processing cost for forming the alignment layer. As an alignment layer, it is resistant to heat so as not to dissolve in a solvent contained in a composition (composition for forming a polarizing layer to be described later) applied in a subsequent process thereon, and for heat treatment during forming a polarizing layer such as solvent removal. It is preferable to have heat resistance and sufficient adhesion to the transparent substrate. Furthermore, when the alignment layer is given an alignment regulation force by a rubbing method or the like, friction is applied to the coating film for forming the alignment layer, so the coating film for forming the alignment layer or the alignment layer It is preferable that the compound constituting the compound (for example, an orientation polymer described later) has a property that it is not modified by the friction or the like, or the alignment layer itself is not peeled off from the transparent substrate by the friction or the like. In that the alignment layer can be easily formed, the alignment layer can be formed from the alignment polymer or the composition containing the alignment polymer, or the photo-alignment polymer or the composition containing the photo-alignment polymer. preferable.

Hereinafter, the alignment polymer and photo-alignment polymer for forming the alignment layer will be described.
Examples of preferred orientation polymers include polyamides having an amide bond in the molecule; gelatins; polyimides having an imide bond in the molecule and polyamic acid which is a hydrolyzate thereof; polyvinyl alcohol; alkyl-modified polyvinyl alcohol; polyacrylamide; Polymers such as oxazole; polyethyleneimine; polystyrene; polyvinylpyrrolidone; polyacrylic acid and polyacrylates. These polymers may be used alone or in combination of two or more for forming the alignment layer, and a copolymer having a plurality of types of structural units constituting these polymers may be used for forming the alignment layer. As mentioned above, although the suitable example of the orientation polymer was shown, polyvinyl alcohol is especially preferable as an orientation polymer among these. Depending on the type of these oriented polymers, polycondensation by dehydration polymerization, deamination polymerization, etc., chain polymerization such as radical polymerization, anionic polymerization and cationic polymerization, coordination polymerization and ring-opening polymerization are known. It can be easily produced by this polymerization method.

  As the photo-alignment polymer, a polymer having a photosensitive structure is used. When a polymer having a photosensitive structure is irradiated with polarized light, the photo-alignable polymer is oriented by isomerizing or cross-linking the photosensitive structure of the irradiated portion. Is applied to form an alignment layer. Examples of the photosensitive structure include an azobenzene structure, a maleimide structure, a chalcone structure, a cinnamic acid structure, a 1,2-vinylene structure, a 1,2-acetylene structure, a spiropyran structure, a spirobenzopyran structure, and a fulgide structure. . The polymer having any photosensitive structure selected from these may be used alone or in combination of two or more in forming the alignment layer. In addition, these photo-alignment polymers are composed of a monomer having a photosensitive structure (monomer), polycondensation by dehydration polymerization, deamine polymerization, etc., chain polymerization such as radical polymerization, anionic polymerization and cationic polymerization, coordination. A known polymerization method such as polymerization or ring-opening polymerization can be selected and easily produced. Further, a plurality of types of monomers having different photosensitive structures may be used as a copolymer.

  As a method of forming an alignment layer from an alignment polymer or a photo-alignment polymer, a method in which the alignment polymer or the photo-alignment polymer is dissolved in a solvent is prepared, and the method using the composition is operated. It is preferable in terms of simplicity. Hereinafter, the composition capable of forming the alignment layer is sometimes referred to as “alignment layer forming composition”. For example, when the composition for forming an alignment layer is applied onto a transparent substrate and the solvent is removed from the coating film by a heating operation or a reduced pressure operation, the alignment layer can be easily provided on the transparent substrate. The solvent used in the composition for forming an alignment layer can be appropriately selected depending on the type and amount of the alignment polymer or photo-alignment polymer used. Specific examples include water; methanol, ethanol, ethylene glycol, isopropyl alcohol, and propylene glycol. Alcohol solvents such as methyl cellosolve, butyl cellosolve and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate and ethyl lactate; acetone, methyl ethyl ketone, cyclopenta Ketone solvents such as non, cyclohexanone, methyl amyl ketone and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; Tetrahydrofuran and ether solvents such as dimethoxyethane; aromatic hydrocarbon solvents such as toluene and xylene, nitriles solvents such as acetonitrile, such as chloroform and chlorinated hydrocarbon solvents such as chlorobenzene and the like. These solvents may be used alone or in combination of two or more.

  Moreover, in order to form an orientation layer, a commercially available composition for orientation layer formation can also be used. Examples of commercially available alignment layer forming compositions include “Sunever” (Nissan Chemical Industry Co., Ltd.) and “Optomer” (JSR Co., Ltd.). Use of such a commercially available composition for forming an alignment layer is advantageous in that an alignment layer with little unevenness can be formed, and that an alignment layer having good environmental resistance and mechanical resistance can be formed.

  As a method of forming an alignment layer using the alignment layer forming composition, the transparent substrate is coated with the alignment layer forming composition and then heat-treated (annealed). A coating film for forming an alignment layer is formed thereon. The thickness of the coating film for forming the alignment layer thus obtained is determined so that the alignment layer obtained after the alignment regulating force is applied has a desired thickness. The thickness of the alignment layer is, for example, 10 nm to 10000 nm, preferably 10 nm to 1000 nm. The thickness of the alignment layer can be controlled by adjusting the conditions for applying the alignment layer forming composition.

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

  As a method for rubbing the coating film for forming the alignment layer, for example, a rubbing cloth is wound and a rotating rubbing roll is prepared, and the coating film (coating film for forming the alignment layer) is formed on a transparent substrate. A method of bringing the coated film and the rotating rubbing roll into contact with each other by placing the laminated body on which the film is formed on a stage and transporting the laminated body toward the rotating rubbing roll can be mentioned. Further, the alignment regulating force may be imparted to the coating film by irradiating the coating film for forming the alignment layer (photo-alignment layer) with polarized light (preferably, polarized UV). If masking is performed when rubbing or polarized light irradiation is performed, a plurality of regions (patterns) having different slow axis directions can be formed in the obtained polarizer.

<Step (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 method as described above. Again, this method will be described. First, a composition containing a polymerizable liquid crystal compound, a dichroic dye, a polymerization initiator, and a solvent (hereinafter, sometimes referred to as “a polarizing layer forming composition”) is applied onto the alignment layer to form a first. A coating film is formed, and the first coating film is dried to remove the solvent, thereby forming a first dry film. Then, a polarizing layer is formed by polymerizing the polymerizable liquid crystal compound in the first dry 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 in this manner, first, the phase transition temperature of the polymerizable liquid crystal compound to be used is measured, and the temperature at which the smectic phase can be maintained is obtained. The polymerizable liquid crystal compound may be polymerized under a temperature condition lower than the temperature, but the lower the polymerization temperature for polymerizing the polymerizable liquid crystal compound, the better. The measurement conditions for measuring the phase transition temperature will be described in the examples of the present application.

  The thickness of the polarizing layer is usually in the range of 0.5 to 10 μm, and more preferably in the range of 0.5 to 3 μm. Therefore, the thickness of the first coating film is determined in consideration of the thickness of the obtained polarizing layer. The thickness of the polarizing layer is obtained by measurement with an interference film thickness meter, a laser microscope or a stylus thickness meter.

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

  Examples of the smectic phase include a smectic B phase, a smectic D phase, a smectic E phase, a smectic F phase, a smectic G phase, a smectic H phase, a smectic I phase, a smectic J phase, a smectic K phase, and a smectic L phase. Among these, higher-order smectic phases such as a smectic B phase, a smectic F phase, a smectic I phase, a tilted smectic F phase, and a tilted smectic I phase are preferable, and a smectic B phase is more preferable. If a composition for forming a polarizing layer in which the liquid crystal phase exhibited by the polymerizable liquid crystal compound can be the liquid crystal phase, a polarizing layer having a high degree of alignment order can be formed.

As a preferable polymerizable liquid crystal composition, for example, a compound represented by the formula (1) (hereinafter sometimes referred to as “compound (1)”) may be mentioned.

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

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. Are more preferably a p-phenylene group which may have a substituent.
The p-phenylene group is preferably unsubstituted. The cyclohexane-1,4-diyl group is preferably a trans-cyclohexane-1,4-diyl group, and more preferably unsubstituted.

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

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

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

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

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 a specific example of the compound (1) has a cyclohexane-1,4-diyl group, the cyclohexane-1,4-diyl group is preferably a trans isomer.

  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 obtained, and other than the polymerizable liquid crystal compound of the composition for forming a polarizing layer so that the compound (1) can be polymerized under a temperature condition lower than the phase transition temperature. Adjust the ingredients. Examples of the component capable of controlling the polymerization temperature include a photopolymerization initiator, a photosensitizer, and a polymerization inhibitor described later. The polymerization temperature of compound (1) can be controlled by adjusting these types and amounts as appropriate. In the case where a mixture of two or more kinds of compounds (1), that is, a polymerizable liquid crystal mixture is used for the composition for forming a polarizing layer, the polymerizable liquid crystal is obtained after determining the phase transition temperature of the polymerizable liquid crystal mixture. The polymerization temperature is controlled as in the case of the compound.

  As the polymerizable liquid crystal compound used in the composition for forming a polarizing layer, among the exemplified compounds (1), formula (1-3), formula (1-6), formula (1-7), formula (1- What is represented by 12) or Formula (1-13) is preferable. These compounds (1) easily interact with the photopolymerization initiator used together under the temperature conditions below the phase transition temperature, that is, while sufficiently maintaining the liquid crystal state of the higher order smectic phase. Compound (1) can be polymerized. More specifically, due to the interaction with the photopolymerization initiator, these compounds (1) sufficiently exhibit a liquid crystal state of a high-order smectic phase under a temperature condition of 70 ° C. or less, preferably 60 ° C. or less. It can be polymerized while being held.

  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, but preferably a plurality of species, and the exemplified compound (1 ) Is more preferable. 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. In addition, all of the compound (1) represented by the above formula (1-1) to formula (1-21) corresponds to a polymerizable smectic liquid crystal compound.

  The content of the polymerizable liquid crystal compound in the polarizing layer forming composition is preferably 70 to 99.9% by mass, more preferably 90 to 99.9% by mass, based on the solid content of the polarizing layer forming composition. preferable. If the content rate of this polymeric liquid crystal compound is in the said range, there exists a tendency for the orientation of a polymeric liquid crystal compound to become high. Here, solid content means the total amount of the component remove | excluding volatile components, such as a solvent, from this polarizing layer formation composition. When using the compound (1) as the polymerizable liquid crystal compound, the content ratio of the compound (1) to the composition for forming a polarizing layer may be in the above range. When multiple types of compounds (1) are contained in the composition for forming a polarizing layer, the total content may be in the above range.

  The composition for forming a polarizing layer preferably contains a leveling agent. The leveling agent has a function of adjusting the fluidity of the polymerizable liquid crystal compound and flattening the first coating film obtained by coating the polarizing layer forming composition. 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 having a polyacrylate compound as a main component and a leveling agent having a fluorine atom-containing compound as a main component.

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

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

  When the leveling agent is contained in the polarizing layer forming composition, the content is preferably 0.3 parts by mass or more and 5 parts by mass or less, and 0.5 parts by mass or more with respect to 100 parts by mass of the polymerizable liquid crystal compound. 3 parts by mass or less is more preferable. When the content of the leveling agent is within the above range, it is easy to horizontally align the polymerizable liquid crystal composition, and the obtained polarizing layer tends to be smoother. On the other hand, when the content of the leveling agent with respect to the polymerizable liquid crystal compound exceeds the above range, unevenness tends to occur in the obtained polarizing layer. In addition, this polarizing layer formation composition may contain 2 or more types of leveling agents.

  The polarizing layer forming composition contains a dichroic dye. The dichroic dye as used herein 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 these dyes may be used, a plurality of pigments may be used, or a dye and a pigment may be combined.

  The dichroic dye preferably has a maximum absorption wavelength (λMAX) in the range of 300 to 700 nm. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes and anthraquinone dyes, and among them, azo dyes are preferable. Examples of the azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, and stilbene azo dyes, with bisazo dyes and trisazo dyes being preferred.

Examples of the azo dye include a compound represented by the formula (2) (hereinafter sometimes referred to as “compound (2)”).
_{^{A 1 (-N = N-A}} 2) p -N = N-A 3 (2)
[In Formula (2),
A ¹ and A ³ are each independently 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. Represents. 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 ring which may have a substituent. Represents a group. p represents an integer of 1 to 4. When p is 2 or more, the plurality of A ² may be the same as or different from each other. ]

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

As a substituent which the phenyl group, naphthyl group and monovalent heterocyclic group in A ¹ and A ³ and the p-phenylene group, naphthalene-1,4-diyl group and divalent heterocyclic group in A ² optionally have Is 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; a cyano group; Nitro group; halogen atom; substituted or unsubstituted amino group such as amino group, diethylamino group and pyrrolidino group (substituted amino group is an amino group having one or two alkyl groups having 1 to 6 carbon atoms, or two This means an amino group in which substituted alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms, and the unsubstituted amino group is —NH ₂ . In addition, the specific example of a C1-C6 alkyl group is the same as what was illustrated with the substituent which the phenylene group etc. of a compound (1) have arbitrarily.

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

［式（２−１）〜（２−６）中、
Ｂ^１〜Ｂ^２０は、互いに独立に、水素原子、炭素数１〜６のアルキル基、炭素数１〜４のアルコキシ基、シアノ基、ニトロ基、置換又は無置換のアミノ基（置換アミノ基及び無置換アミノ基の定義は前記のとおり）、塩素原子又はトリフルオロメチル基を表す。
ｎ１〜ｎ４は、互いに独立に０〜３の整数を表す。
ｎ１が２以上である場合、複数のＢ^２は互いに同一でも異なっていてもよく、
ｎ２が２以上である場合、複数のＢ^６は互いに同一でも異なっていてもよく、
ｎ３が２以上である場合、複数のＢ^９は互いに同一でも異なっていてもよく、
ｎ４が２以上である場合、複数のＢ¹⁴は互いに同一でも異なっていてもよい。］

[In the formulas (2-1) to (2-6),
B ^{1 to} B ²⁰ are each independently 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 (a substituted amino group and As defined above, the unsubstituted amino group represents a chlorine atom or a trifluoromethyl group.
n1 to n4 each independently represents an integer of 0 to 3.
when n1 is 2 or more, the plurality of B ² may be the same as or different from each other;
when n2 is 2 or more, the plurality of B ⁶ may be the same as or different from each other;
when n3 is 2 or more, the plurality of B ⁹ may be the same as or different from each other;
When n4 is 2 or more, the plurality of B ¹⁴ may be the same as or different from each other. ]

  Such an azo dye may be easily available from the market. Examples of commercially available azo dyes that can be used in the polarizing layer forming composition include “NKX2029” and “G205” (produced by Hayashibara Biochemical Laboratories).

［式（２−７）中、
Ｒ^１〜Ｒ^８は、互いに独立に、水素原子、−Ｒ^ｘ、−ＮＨ_２、−ＮＨＲ^ｘ、−ＮＲ^ｘ _２、−ＳＲ^ｘ又はハロゲン原子を表す。
Ｒ^ｘは、炭素数１〜４のアルキル基又は炭素数６〜１２のアリール基を表す。］ As said anthraquinone pigment | dye, the compound represented by Formula (2-7) is preferable.

[In the formula (2-7),
R ^{1 to} R ⁸ each 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. ]

［式（２−８）中、
Ｒ^９〜Ｒ^１５は、互いに独立に、水素原子、−Ｒ^ｘ、−ＮＨ_２、−ＮＨＲ^ｘ、−ＮＲ^ｘ _２、−ＳＲ^ｘ又はハロゲン原子を表す。
Ｒ^ｘは、炭素数１〜４のアルキル基又は炭素数６〜１２のアリール基を表す。］ As the acridine dye, a compound represented by the formula (2-8) is preferable.

[In the formula (2-8),
R ^{9 to} R ¹⁵ each 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. ]

［式（２−９）中、
Ｒ^１６〜Ｒ^２３は、互いに独立に、水素原子、−Ｒ^ｘ、−ＮＨ_２、−ＮＨＲ^ｘ、−ＮＲ^ｘ _２、−ＳＲ^ｘ又はハロゲン原子を表す。
Ｒ^ｘは、炭素数１〜４のアルキル基又は炭素数６〜１２のアリール基を表す。］ As the oxazone dye, a compound represented by the formula (2-9) is preferable.

[In 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 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 of R ^x is a methyl group, an ethyl group, a propyl group, a butyl group, or the like. Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a toluyl group, a xylyl group, and a naphthyl group.

［式（２−１０）中、
Ｄ^１及びＤ^２は、互いに独立に、式（２−１０ａ）〜式（２−１０ｄ）のいずれかで表される基を表す。

ｎ５は１〜３の整数を表す。］ As the cyanine dye, a compound represented by the formula (2-10) and a compound represented by the formula (2-11) are preferable.

[In the formula (2-10),
D ¹ and D ² each independently represent a group represented by any one of formulas (2-10a) to (2-10d).

n5 represents an integer of 1 to 3. ]

［式（２−１１）中、
Ｄ^３及びＤ^４は、互いに独立に、式（２−１１ａ）〜式（２−１１ｈ）のいずれかで表される基を表す。

ｎ６は１〜３の整数を表す。］

[In the formula (2-11),
D ³ and D ⁴ each 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 can be appropriately adjusted according to the type of the dichroic dye, and is, for example, 0. 1 mass part or more and 50 mass parts or less are preferable, 0.1 mass part or more and 20 mass parts or less are more preferable, and 0.1 mass part or more and 10 mass parts or less are more preferable. If the content of the dichroic dye is within this range, the polymerizable liquid crystal compound can be polymerized while maintaining the liquid crystal state of the higher order smectic phase without disturbing the alignment of the polymerizable liquid crystal compound. . When there is too much content of a dichroic dye, there exists a possibility of inhibiting the orientation of a polymerizable liquid crystal compound. Therefore, the content of the dichroic dye can be determined within a range in which the polymerizable liquid crystal compound can maintain a liquid crystal state of a higher order smectic phase.

  The polarizing layer forming composition contains a solvent. As the solvent, a preferable one can be appropriately selected in consideration of the solubility of the polymerizable liquid crystal compound to be used. However, an inert solvent that does not significantly disturb the progress of the polymerization reaction of the polymerizable liquid crystal compound is preferable. Such solvents include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether and propylene glycol monomethyl ether; ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, ester solvents such as γ-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 hydrocarbons such as pentane, hexane and heptane Solvents; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solutions such as acetonitrile ; Ether solvents such as tetrahydrofuran and dimethoxyethane; such as chloroform and chlorine-containing solvents such as chlorobenzene and the like. These solvents may be used alone or in combination of two or more.

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

  The polarizing layer forming composition contains a polymerization initiator. The said polymerization initiator is a compound which can start the polymerization reaction of a polymeric liquid crystal compound, and a photoinitiator is preferable at the point which can start the said polymerization reaction under lower temperature conditions. Specifically, a compound capable of generating an active radical or an acid by the action of light under a low temperature condition (this low temperature means a temperature of 70 ° C. or lower, preferably 60 ° C. or lower as described above) is a photopolymerization initiator. Used as Among the photopolymerization initiators, those that generate radicals by the action of light are more preferable.

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

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

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

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

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

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

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

  The content of the polymerization initiator in the polarizing layer forming composition can be appropriately adjusted according to the type and amount of the polymerizable liquid crystal compound contained in the polarizing layer forming composition. For example, the polymerizable liquid crystal compound 0.1-30 mass parts is preferable, as for content of the polymerization initiator with respect to a total of 100 mass parts, 0.5-10 mass parts is more preferable, 0.5-8 mass parts is further more preferable. If the content of the polymerizable initiator is within this range, the polymerizable liquid crystal compound can be polymerized without disturbing the alignment of the polymerizable liquid crystal compound, so that the liquid crystal state of the higher smectic phase is maintained. Can be polymerized.

  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 xanthone compounds such as xanthone and thioxanthone (for example, 2,4-diethylthioxanthone and 2-isopropylthioxanthone); anthracene and alkoxy-containing anthracene (for example, dibutoxyanthracene) and the like. Anthracene compounds; 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 the photosensitizer used can be appropriately adjusted according to the type and amount of the photopolymerization initiator and the polymerizable liquid crystal compound to be used in combination. 0.1-30 mass parts is preferable, 0.5-10 mass parts is more preferable, 0.5-8 mass parts is further more preferable.

  It has been explained that the polymerization reaction of the polymerizable liquid crystal compound can be promoted by including a photosensitizer in the composition for forming a polarizing layer, but in order to promote the polymerization reaction stably, the composition for forming the polarizing layer is used. The composition can also contain a polymerization inhibitor appropriately. By containing the polymerization inhibitor, the degree of progress of the polymerization reaction of the polymerizable liquid crystal compound can be controlled.

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

  When the polymerization inhibitor is contained in the polarizing layer forming composition, the content can be appropriately adjusted according to the type and amount of the polymerizable liquid crystal compound to be used, the amount of the photosensitizer used, and the like. For example, the content of the polymerization inhibitor is preferably from 0.1 to 30 parts by weight, more preferably from 0.5 to 10 parts by weight, and even more preferably from 0.5 to 8 parts by weight with respect to 100 parts by weight of the total polymerizable liquid crystal compound. preferable. If the content of the polymerization inhibitor is within this range, it can be polymerized without disturbing the orientation of the polymerizable liquid crystal compound or polymerizable liquid crystal composition contained in the polarizing layer forming composition, The polymerizable liquid crystal compound or the polymerizable liquid crystal composition can be polymerized while maintaining a liquid crystal state of a high-order smectic phase.

  The composition for forming a polarizing layer described above is applied onto an alignment layer of a laminate having a transparent substrate and an alignment layer to obtain a first coating film, and the polymerizable liquid crystal contained in the first coating film A 1st dry film is formed by drying on the conditions which a compound does not superpose | polymerize.

  Examples of a method (coating method) for applying the polarizing layer forming composition to the laminated plate include an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, a CAP coating method, a die coating method, a dip coating method, and a bar. Examples thereof include a coating method and a spin coating method. In addition, these application | coating methods are applicable also when apply | coating the composition for alignment layer formation on a transparent base material. The application conditions are set so that the thickness of the obtained polarizing layer is within the above-mentioned preferable range.

  Subsequently, by drying the first coating film, the solvent is removed from the first coating film to form a first dry film. When removing the solvent, volatile components other than the solvent contained in the first coating film are also removed. As a method for removing the solvent, a drying means (drying method) is usually used, and natural drying method, ventilation drying method, reduced pressure drying method, or a combination thereof can be used. Any drying method may be used, but it is preferable to set the drying conditions so that the polymerizable liquid crystal compound contained in the first coating film is not polymerized.

<Step (3)>
In the step (3), the polymerizable liquid crystal compound is polymerized while the liquid crystal state of the polymerizable liquid crystal composition contained in the first dry film is maintained in the smectic liquid crystal state, thereby polarizing the first dry film. Form a layer.

<Formation of polarizing layer>
In order to change the liquid crystal state of the polymerizable liquid crystal compound contained in the first dry film into a smectic phase (hereinafter, sometimes referred to as “smectic phase” or “liquid crystal state of smectic phase”), the first dry film is formed. What is necessary is just to heat to suitable temperature, and what is necessary is just to heat what consists of a laminated board which has this 1st dry film to suitable temperature calculated | required from the phase transition temperature. In forming the smectic phase, it is preferable that the liquid crystal state of the polymerizable liquid crystal compound contained in the first dry film is once changed to a nematic phase (nematic liquid crystal state) and then the nematic phase is changed to the smectic phase. In order to form a smectic phase via the nematic phase in this way, for example, the polymerizable liquid crystal compound contained in the first dry film is heated to a temperature higher than the temperature at which the liquid crystal state of the nematic phase is changed, and then the polymerizable property is changed. A method in which the liquid crystal compound is cooled to a temperature at which the liquid crystal state of the smectic phase is exhibited is employed.

  In forming the smectic phase liquid crystal state via the nematic phase, it is particularly preferable that the polarizing layer forming composition contains the above-described leveling agent. When a leveling agent is contained in the first dry film when forming the liquid crystal state, the leveling agent easily flows in the first dry film, and the polymerizable liquid crystal compound or the polymerizable liquid crystal composition is horizontal. There is an advantage that it becomes easy to orient. The temperature at which the nematic phase and the smectic phase are formed is preferably in the range from the nematic phase transition point to a temperature not higher than 100 ° C. higher than the nematic phase transition point, higher than the nematic phase transition point and higher than the nematic phase transition point by 50 ° C. The range below the temperature is more preferable. The heat treatment for aligning the desired liquid crystal phase and the above-described solvent drying treatment can be performed simultaneously.

  When the polymerizable liquid crystal compound is polymerized, a polymerizable liquid crystal mixture composed of two or more polymerizable liquid crystal compounds as the polymerizable liquid crystal compound (more preferably, It is preferable to use a composition for forming a polarizing layer containing a polymerizable liquid crystal mixture comprising two or more polymerizable smectic liquid crystal compounds. When a polarizing layer forming composition 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 of a smectic phase is formed via a nematic phase and then temporarily cooled. It is possible to form a state, and there is an advantage that a liquid crystal state of a higher order smectic phase is easily maintained.

  Here, after the photopolymerization initiator is contained in the composition for forming a polarizing layer and the liquid crystal state of the polymerizable liquid crystal compound in the first dry film is changed to a smectic phase, the liquid crystal state of the smectic phase is maintained, A method for photopolymerizing the polymerizable liquid crystal compound will be described in detail. In the photopolymerization, the light beam applied to the first dry film includes the type of photopolymerization initiator contained in the first dry film, or the type of polymerizable liquid crystal compound (in particular, the photopolymerizable group possessed by the polymerizable liquid crystal compound). Depending on the type and amount thereof, it can be carried out by light or active electron beam selected from the group consisting of visible light, ultraviolet light and laser light. Among these, ultraviolet light is preferable in that it is easy to control the progress of the polymerization reaction and that apparatuses widely used in the field as photopolymerization apparatuses can be used. Therefore, it is preferable to select the type of the polymerizable liquid crystal compound and the photopolymerization initiator contained in the polarizing layer forming composition so that the photopolymerization can be performed with ultraviolet light. Moreover, when superposing | polymerizing, superposition | polymerization temperature can also be controlled by cooling a 1st dry film with a suitable cooling means with ultraviolet light irradiation. If the polymerizable liquid crystal compound can be polymerized at a lower temperature by employing such a cooling means, the polarizing layer can be appropriately formed even if the transparent substrate and the alignment layer described above have relatively low heat resistance. There is also an advantage that it can be formed. In the photopolymerization, a patterned polarizing layer can be obtained by masking or developing.

  By performing photopolymerization as described above, the polymerizable liquid crystal compound is polymerized while maintaining a liquid crystal state of a smectic phase, preferably a higher-order smectic phase as exemplified above, and a polarizing layer is formed. . A polarizing layer obtained by polymerizing a polymerizable liquid crystal compound or a polymerizable liquid crystal composition while maintaining a liquid crystal state of a smectic phase is a conventional polarizing layer, that is, a polymerizable liquid crystal compound while maintaining a liquid crystal state of a nematic phase There is an advantage that the polarization performance is much higher than that of a polarizing layer obtained by polymerizing the above.

  Moreover, it is particularly preferable that the polarizing layer thus formed has a Bragg peak in X-ray diffraction measurement. Examples of the polarizing layer from which such a Bragg peak is obtained include a polarizing layer that exhibits a diffraction peak derived from a hexatic phase or a crystal phase. Examples of the measurement conditions for such X-ray diffraction measurement include the conditions described in the examples of the present application.

<Process (4)>
Step (4) is a step of forming a protective layer on the polarizing layer of the laminate provided with the alignment layer and the polarizing layer in this order on the transparent substrate obtained in step (3). When the polarizing layer in the present polarizer is a polarizing layer formed by polymerizing a polymerizable liquid crystal compound in a liquid crystal state of a higher order smectic phase such as a smectic B phase, the polarizing layer is remarkably It may be altered by factors of the external environment. By forming a protective layer on the polarizing layer, alteration of the polarizing layer can be extremely effectively prevented.
As step (4),
On the polarizing layer formed in the step (3), a protective layer-forming composition 1 containing a polyfunctional acrylate and a solvent is applied to form a second coating film on the polarizing layer, A step (4-1) of forming a protective layer from the second coating film by polymerizing the polyfunctional acrylate contained in the second coating film;
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), and the polarizing layer is coated on the polarizing layer. Forming a second coating film and drying the second coating film to form a protective layer from the second coating film (4-2); and
On the polarizing layer formed in the step (3), a protective layer-forming composition 3 containing a water-soluble polymer and water is applied to form a second coating film on the polarizing layer, A step (4-3) of forming a protective layer from the second coating film by drying the second coating film;
Etc.

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

<Composition 1 for protective layer formation>
The protective layer-forming composition 1 contains a polyfunctional acrylate and a solvent. The polyfunctional acrylate contained in the protective layer-forming composition 1 is selected from the group consisting of an acrylate group (CH ₂ ═CH—CO—) and a methacrylate group (CH ₂ ═C (CH ₃ ) —CO—). It means a compound having two or more groups in the molecule and having no liquid crystallinity like the compound (1). Preferred polyfunctional acrylates are compounds having 2 to 6 groups in the molecule selected from the group consisting of acrylate groups and methacrylate groups. A polyfunctional acrylate having two such groups is hereinafter referred to as “bifunctional acrylate” or the like depending on the number of the groups, and a polyfunctional acrylate having three or more such groups is referred to as “trifunctional or more functional”. It is called “polyfunctional acrylate”.
Furthermore, the polyfunctional acrylate contained in the protective layer forming composition 1 is such that when the polyfunctional acrylate is cured to form a protective layer, the protective layer can transmit light, particularly visible light. Those having transparency are selected. Here, “transparency to the extent that visible light can be transmitted” has the same meaning as described for the transparency of the transparent substrate.

Here, preferred polyfunctional acrylates are exemplified.
Examples of the bifunctional acrylate having two groups selected from the group consisting of an acrylate group and a methacrylate group in the molecule 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 Rate; and ethoxylated neopentyl glycol di (meth) acrylate and 3-methyl-pentanediol di (meth) acrylate.

As a polyfunctional acrylate having 3 to 6 functional groups having 3 to 6 groups selected from the group consisting of acrylate groups and methacrylate groups,
Trimethylolpropane tri (meth) acrylate; pentaerythritol tri (meth) acrylate; tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate; ethoxylated trimethylolpropane tri (meth) acrylate; propoxylated trimethylolpropane tri ( Pentaerythritol tetra (meth) acrylate; dipentaerythritol penta (meth) acrylate; dipentaerythritol hexa (meth) acrylate; tripentaerythritol tetra (meth) acrylate; tripentaerythritol penta (meth) acrylate; tripenta Erythritol hexa (meth) acrylate; tripentaerythritol hepta (meth) acrylate; tripentaerythritol o Data (meth) acrylate;
Reaction product of pentaerythritol tri (meth) acrylate and acid anhydride; Reaction product of dipentaerythritol penta (meth) acrylate and 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 tripentaerys Tall hepta (meth) acrylate; caprolactone-modified tripentaerythritol octa (meth) acrylate; reaction product of caprolactone-modified pentaerythritol tri (meth) acrylate and acid anhydride; caprolactone-modified dipentaerythritol penta (meth) acrylate and acid anhydride And a reaction product of the above, and caprolactone-modified tripentaerythritol hepta (meth) acrylate and an acid anhydride. In addition, in the specific example of the polyfunctional acrylate shown here, (meth) acrylate means an acrylate or a methacrylate. The caprolactone modification means that a ring-opened product of caprolactone or a ring-opened 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 high surface hardness, among the above-described specific examples of the polyfunctional acrylate, it is preferable to use a trifunctional or higher polyfunctional acrylate, and it is particularly preferable to use a hexafunctional acrylate. Moreover, the said composition 1 for protective layer formation may contain 1 type of polyfunctional acrylate, or multiple types of polyfunctional acrylate may contain.

Further, from the viewpoint of the printability of the protective layer forming composition 1 and the tackiness of the protective layer to be obtained, the protective layer forming composition 1 may contain a binder resin.
The binder resin is a copolymer of at least one monomer selected from the group consisting of an unsaturated carboxylic acid and an unsaturated carboxylic acid anhydride and another monomer copolymerizable with the monomer. Examples include coalescence.
Specific examples of unsaturated carboxylic acids 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; Unsaturated mono [(meth) acryloyloxyalkyl] esters of divalent or higher polyvalent carboxylic acids such as 2- (meth) acryloyloxyethyl] and phthalic acid mono [2- (meth) acryloyloxyethyl]; α Examples thereof include unsaturated acrylates containing a hydroxy group and a carboxy group in the same molecule, such as-(hydroxymethyl) acrylic acid. The unsaturated carboxylic acid anhydride corresponds to the unsaturated carboxylic acid anhydride shown here. Among these, acrylic acid, methacrylic acid, maleic anhydride and the like are preferable as the monomer for producing the binder resin. These acrylic acid, methacrylic acid and maleic anhydride have good polymerization reactivity when copolymerized with various other monomers, and the resulting binder resin has high glass transition temperature (Tg) and mechanical properties, and has good tackiness. It is preferably used because it does not exist. In addition, when manufacturing binder resin, the monomer chosen from the group which consists of unsaturated carboxylic acid and unsaturated carboxylic anhydride may use single type, or may use multiple types.

As other monomer copolymerizable with a monomer selected from the group consisting of unsaturated carboxylic acid and unsaturated carboxylic acid anhydride,
(Meth) acrylic acid alkyl esters 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 this technical field, dicyclopentanyl is a common name. (Meth) acrylates), (meth) acrylic acid cyclic alkyl esters such as dicyclopentanyloxyethyl (meth) acrylate and isoboronyl (meth) acrylate;
Cyclohexyl acrylate, 2-methylcyclohexyl acrylate, tricyclo [5.2.1.02,6] decan-8-yl acrylate (referred to as dicyclopentanyl acrylate as a common name in the art), dicyclopenta Acrylic acid cyclic alkyl esters such as oxyethyl 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;
Bicyclo [2.2.1] hept-2-ene, 5-methylbicyclo [2.2.1] hept-2-ene, 5-ethylbicyclo [2.2.1] hept-2-ene, 5- Hydroxybicyclo [2.2.1] hept-2-ene, 5-carboxybicyclo [2.2.1] hept-2-ene, 5-hydroxymethylbicyclo [2.2.1] hept-2-ene, 5- (2′-hydroxyethyl) bicyclo [2.2.1] hept-2-ene, 5-methoxybicyclo [2.2.1] hept-2-ene, 5-ethoxybicyclo [2.2.1 ] Hept-2-ene, 5,6-dihydroxybicyclo [2.2.1] hept-2-ene, 5,6-dicarboxybicyclo [2.2.1] hept-2-ene, 5,6- Di (hydroxymethyl) bicyclo [2.2.1] hept-2-e 5,6-di (2′-hydroxyethyl) bicyclo [2.2.1] hept-2-ene, 5,6-dimethoxybicyclo [2.2.1] hept-2-ene, 5,6 -Diethoxybicyclo [2.2.1] hept-2-ene, 5-hydroxy-5-methylbicyclo [2.2.1] hept-2-ene, 5-hydroxy-5-ethylbicyclo [2.2 .1] Hept-2-ene, 5-carboxy-5-methylbicyclo [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] hept-2-ene, 5-carboxy-6- Ethylbicyclo [2.2.1] hept-2-ene, 5, 6-dicarboxybicyclo [2.2.1] hept-2-ene anhydride (hymic acid anhydride), 5-tert-butoxycarbonylbicyclo [2.2.1] hept-2-ene, 5-cyclohexyloxy Carbonyl bicyclo [2.2.1] hept-2-ene, 5-phenoxycarbonylbicyclo [2.2.1] hept-2-ene, 5,6-di (tert-butoxycarbonyl) bicyclo [2.2. 1] Bicyclo unsaturated compounds such as hept-2-ene and 5,6-di (cyclohexyloxycarbonyl) bicyclo [2.2.1] hept-2-ene;
N-phenylmaleimide, N-cyclohexylmaleimide, N-benzylmaleimide, N-succinimidyl-3-maleimidobenzoate, N-succinimidyl-4-maleimidobutyrate, N-succinimidyl-6-maleimidocaproate, N-succinimidyl-3 Dicarbonylimide derivatives such as maleimide propionate and N- (9-acridinyl) maleimide;
Styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, vinyl toluene, p-methoxystyrene, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, acrylamide, methacrylamide, vinyl acetate, 1,3-butadiene , Isoprene and 2,3-dimethyl-1,3-butadiene.

  Examples of the solvent contained in the protective layer forming composition 1 include the same solvents as those exemplified as the solvent contained in the polarizing layer forming composition. Among these, the solvent contained in the protective layer forming composition 1 preferably includes a solvent selected from the group consisting of an alcohol solvent and an ether solvent, and further includes substantially an alcohol solvent and / or an ether solvent. preferable. Here, “a solvent substantially consisting of an alcohol solvent and / or an ether solvent” means that the solvent other than the alcohol solvent is hardly contained, the solvent other than the ether solvent is hardly contained, the alcohol solvent And a solvent that contains almost no solvent other than the ether solvent. However, a solvent that is substantially composed of an alcohol solvent and / or an ether solvent may contain moisture or the like that is unintentionally contained so long as it can form a protective layer. Examples of the alcohol solvent include methanol, ethanol, butanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether as described above. Examples of the ether solvent include ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate. Among these, as a solvent contained in the composition for forming a polarizing layer, ethanol, isopropyl alcohol, propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate, and a plurality of mixed solvents selected from these are more preferable.

  When the solvent 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 protective layer can be formed while maintaining the orientation state without significantly impairing the orientation state of the layer. In this respect, the polarizer can be stably produced when the solvent contained in the composition 1 for forming a protective layer is substantially composed of an alcohol solvent and / or an ether solvent. In addition, the method of forming a protective layer using the protective layer-forming composition 1 as described above is also advantageous in that the operation is simple. The content of the solvent contained in the protective layer forming composition 1 may be determined in consideration of applicability when the protective layer forming composition 1 is applied on the polarizing layer. The content of the solvent is preferably 10 to 80 parts by mass, and more preferably 20 to 60 parts by mass with respect to 100 parts by mass of the total amount of the protective layer forming composition 1.

  When forming a protective layer from the protective layer forming composition 1, it is necessary to polymerize and cure the polyfunctional acrylate contained in the protective layer forming composition 1. In the polymerization of the polyfunctional acrylate, photopolymerization as described in the polymerization of the polymerizable liquid crystal compound contained in the polarizing layer forming composition is preferable. The photopolymerization of the polyfunctional acrylate can be carried out by irradiating the second dry film formed on the polarizing layer by the protective layer forming composition 1 with visible light or ultraviolet rays. In order to efficiently carry out photopolymerization of the polyfunctional acrylate, the protective layer forming composition 1 preferably contains a photopolymerization initiator. As the said photoinitiator, the same thing as what was illustrated as a photoinitiator contained in the said composition for polarizing layer formation is illustrated.

Hereinafter, the operation of forming the protective layer will be briefly described.
To form the protective layer, first, the protective layer forming composition 1 is applied onto the polarizing layer to form a second coating film. The method for applying the protective layer forming composition 1 is the same as that described as the method for applying the polarizing layer forming composition, 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 dry film. The same method as exemplified as the drying method for forming the first dry film from the first coating film can also be adopted for this drying. In the process of drying the second dry film, it is necessary to prevent the unpolymerized polymerizable liquid crystal compound from being mixed from the polarizing layer into the second dry film during drying. As temperature conditions for that, the range of about 0-60 degreeC is preferable, and the range of about 20-50 degreeC is further more preferable.
When the solvent contained in the composition 1 for forming a protective layer is a solvent described as a more preferable solvent, the second coating film can be dried under such suitable temperature conditions. In addition, in order to dry in such a temperature range, you may hold | maintain a 2nd coating film on suitable pressure reduction conditions depending on the kind of solvent contained in the said composition 1 for protective layer formation.

  The present inventors have found that when the protective layer-forming composition 1 substantially consisting of an alcohol solvent and / or an ether solvent is applied as a solvent on the polarizing layer, the properties of the polarizing layer are not impaired. Accordingly, if a protective layer is formed on the polarizing layer using the protective layer forming composition 1, not only can the protective layer prevent deterioration of the polarizing layer of the present polarizer over time, but the protective layer is formed. At times, it is possible to satisfactorily prevent the properties of the polarizing layer from being impaired. Such an effect cannot be immediately found in the production of a conventional polarizer, and is based on the inventors' original knowledge.

  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), and the polarizing layer is coated on the polarizing layer. A method of forming a protective film from the second coating film by forming the second coating film and drying the second coating film will be described. Such a method for forming a protective layer from the protective layer-forming composition 2 has an advantage that the operation is extremely simple.

<Protective layer forming composition 2>
The protective layer-forming composition 2 contains a polymer or oligomer obtained by polymerizing a polyfunctional acrylate and water. Examples of the polymer or oligomer obtained by polymerizing the polyfunctional acrylate include aliphatic urethane acrylate.

  The content of water contained in the protective layer forming composition 2 may be determined in consideration of applicability when the protective layer forming composition 2 is applied on the polarizing layer. The content of water is preferably 50 to 99 parts by mass and more preferably 60 to 95 parts by mass with respect to 100 parts by mass of the total amount of the layer forming composition 2.

Hereinafter, the operation of forming the protective layer will be briefly described.
To form the protective layer, first, the protective layer forming composition 2 is applied onto the polarizing layer to form a second coating film. The method for applying the protective layer-forming composition 2 is the same as that described as the method for applying the polarizing layer-forming composition, for example.
Next, water is removed from the second coating film to obtain a protective layer. For this drying, the same method as exemplified as the method for drying the first coating film can be employed. As temperature conditions, the range of about 0-100 degreeC is preferable, and the range of about 20-80 degreeC is further more preferable.

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

<Protective layer forming composition 3>
The protective layer forming composition 3 contains a water-soluble polymer and water. Examples of the water-soluble polymer include polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinyl pyrrolidone, starches, methyl cellulose, carboxymethyl cellulose, sodium alginate and the like, and preferably polyvinyl alcohol.

  The content of water contained in the protective layer forming composition 3 may be determined in consideration of applicability when the protective layer forming composition 3 is applied on the polarizing layer. The content of water is preferably 50 to 99 parts by mass and more preferably 60 to 95 parts by mass with respect to 100 parts by mass of the total amount of the layer forming composition 3.

Hereinafter, the operation of forming the protective layer will be briefly described.
In order to form a protective layer, first, the protective layer forming composition 3 is applied onto the polarizing layer to form a second coating film. The method for applying the protective layer forming composition 3 is the same as that described as the method for applying the polarizing layer forming composition, for example.
Next, water is removed from the second coating film to obtain a protective layer. For this drying, the same method as exemplified as the method for drying the first coating film can be employed. As temperature conditions, the range of about 0-100 degreeC is preferable, and the range of about 20-80 degreeC is further more preferable.

  Although the thickness of a protective layer can be suitably adjusted according to the kind etc. of polarizing layer protected with a protective layer, it is preferable in the range of 0.1-30 micrometers, for example, and it is further more preferable in the range of 1-5 micrometers. For the thickness measurement, the same method as described as the method for measuring the thickness of the polarizing layer is employed.

<This polarizer>
The polarizer obtained by the production method having the steps (1) to (4) is not only excellent in scratch resistance and solvent resistance on the surface of the polarizing layer by providing a protective layer, but also the polarizer itself. This is advantageous over conventional polarizers in that it has excellent heat resistance and heat and moisture resistance. Moreover, embodiment of the manufacturing method of this polarizer which has a process (1)-a process (4) WHEREIN: The said 1st dry film of the said (1) dry film of a process (3) is 25 +/- 10 degreeC temperature conditions. Various modifications can be made without changing the mode in which the polymerizable liquid crystal compound or the polymerizable liquid crystal composition contained in the coating is polymerized while maintaining the smectic liquid crystal state. For example, when forming or preparing a laminate of the transparent substrate and the alignment layer in step (1), the transparent substrate itself may have an alignment characteristic, or in addition to the alignment layer, a retardation film Can be further laminated on the transparent substrate in the order of the orientation layer, polarizing layer, retardation layer and protective layer. In addition, a bead-shaped resin having a refractive index different from that of the ultraviolet absorber, the antistatic agent, or the component of the protective layer may be mixed in the protective layer formed in the step (4). However, since the protective layer-forming composition used in the formation of the protective layer is advantageously a solvent substantially consisting of an alcohol solvent and / or an ether solvent, or water, It is preferable that a process (4) can be implemented using a composition.

  As mentioned above, although this polarizer was demonstrated centering on the case where it is the form of a laminated body of transparent base material / alignment layer / polarizing layer / protective layer, even if layers other than these are laminated | stacked on this polarizer. Good. As already described, the present polarizer may further include a retardation film, or may further include an antireflection layer or a brightness enhancement film. Moreover, it can also be set as a circularly-polarizing plate combining with a quarter wavelength plate. The quarter-wave plate used when manufacturing the circularly polarizing plate preferably has a characteristic that the in-plane retardation value with respect to visible light becomes smaller as the wavelength becomes shorter.

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

  FIG. 1 is a schematic view schematically showing the simplest cross-sectional configuration of the present polarizer. In order from the transparent substrate 2, an alignment layer 3, a polarizing layer 4 and a protective layer 7 are laminated. In the polarizing layer 4, a dichroic dye 6 is dispersed in a matrix 5 formed by polymerizing a polymerizable liquid crystal compound. ing.

2 and 5 are schematic views schematically showing a cross-sectional configuration of a liquid crystal display device (hereinafter, sometimes referred to as “the present liquid crystal display device”) 10 using the present polarizer. The liquid crystal layer 17 is sandwiched between two bases 14a and a substrate 14b.
4 and 7 are schematic views schematically showing a cross-sectional configuration of an EL display device using the present polarizer (hereinafter sometimes referred to as “the present EL display device”).
FIG. 8 is a schematic view schematically showing a configuration of a projection type liquid crystal display device using the present polarizer.

First, the present liquid crystal display device shown in FIG. 2 will be described.
The polarizer is preferably disposed on the light incident 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 across the liquid crystal layer 17, and the black matrix 20 is disposed at a position facing the boundary between the pixel electrodes. The transparent electrode 16 is disposed on the liquid crystal layer 17 side so as to cover the color filter 15 and the black matrix 20. An overcoat layer (not shown) may be provided between the color filter 15 and the transparent electrode 16.
Thin film transistors 21 and pixel electrodes 22 are regularly arranged on the liquid crystal layer 17 side of the substrate 14b. The pixel electrode 22 is disposed at a position facing the color filter 15 with the liquid crystal layer 17 interposed therebetween. An interlayer insulating film 18 having a connection hole (not shown) is disposed between the thin film transistor 21 and the pixel electrode 22.

A glass substrate and a plastic substrate are used as the substrate 14a and the substrate 14b.
As the glass substrate or plastic substrate, the same material as that exemplified as the transparent base material of the present polarizer can be adopted. When manufacturing the color filter 15 and the thin film transistor 21 formed on the substrate, a glass substrate or a quartz substrate is preferable when a process of heating to a high temperature is required.

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

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

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

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

Among the substrates 14 a and 14 b sandwiching the liquid crystal layer 17, polarizers 12 a and 12 b are provided outside the substrate 14 b, and at least one of these is the polarizer 1.
Furthermore, it is preferable that retardation layers (for example, quarter-wave plates and optical compensation films) 13a and 13b are laminated. By disposing 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 layers 13a and 13b may not be arranged depending on the structure of the liquid crystal display device and the type of liquid crystal compound contained in the liquid crystal layer 17, and may be disposed on the light emitting side (outside) of the polarizer 1. Further, a polarizing film may be provided.
It is preferable that an antireflection film 11 for preventing reflection of external light is disposed outside the main polarizer 1 (outside when a polarizing film is further provided on the main polarizer 1).

  As described above, the polarizer 1 can be used for the polarizer 12a or 12b of the liquid crystal display device 10 of FIG. By providing the polarizer 1 on the polarizers 12a and / or 12b, there is an effect that the liquid crystal display device 10 can be thinned.

When this polarizer 1 is used for the polarizer 12a or 12b, the stacking order is not particularly limited.
This will be described with reference to an enlarged view of portions A and B surrounded by a dotted line in FIG.

  FIG. 3 is an enlarged schematic cross-sectional view of a portion A in FIG. FIG. 3A1 shows that when the polarizer 1 is used as the polarizer 12a, 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 13a side. This shows that the present polarizer 1 is provided. Further, (A2) in FIG. 3 is provided with the present polarizer 1 so that the transparent substrate 2, the alignment layer 3, the polarizing layer 4 and the protective layer 7 are arranged in this order from the phase difference layer 13a side. Indicates that

  FIG. 4 is an enlarged schematic view of a portion B in FIG. FIG. 4B2 shows that when the present polarizer is used as the polarizer 12b, 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 film 13b side. The polarizer 1 is provided.

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

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

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

  Here, depending on the presence or absence of a potential difference between the pixel electrode 22 and the transparent electrode 16 facing the pixel electrode 22, the alignment state of the liquid crystal molecules contained in the liquid crystal layer 17 changes, and the luminance of the light emitted from the liquid crystal display device 10 is controlled. Is done. When the liquid crystal layer 17 is in an alignment state in which the polarized light is transmitted as it is, the polarized light is transmitted through the liquid crystal layer 17 and the transparent electrode 16, and light in a specific wavelength range is transmitted through the color filter 15 and reaches the polarizer 12a. Further, when passing through the antireflection film 11, the liquid crystal display device displays the color determined by the color filter brightest.

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

  When the present liquid crystal display device 10 is a transflective liquid crystal display device, it is preferable to use a laminate in which a quarter wavelength plate is further laminated 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. Is displayed. On the other hand, in the reflection portion, 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 polarizer is converted into a liquid crystal layer by the action of a quarter wave plate further provided in the polarizer. 17 is reflected by the pixel electrode 22 and used for display.

Next, a suitable in-cell type liquid crystal display device (the present liquid crystal display device 24) using the polarizer 1 will be described with reference to FIG.
In the present liquid crystal display device 24, the antireflection film 11, the substrate 14a, the polarizer 12a, the retardation layer 13a, the color filter 15 and the black matrix 20, the transparent electrode 16, the liquid crystal layer 17, the pixel electrode 22, the interlayer insulating film 18, and the thin film transistor. 21, the retardation layer 13b, the polarizer b, the substrate 14b, and the backlight unit 19 are laminated 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 base material 2, the alignment layer 3, the polarizing layer 4, and the protective layer 7 from the antireflection film 11 side.
In the present liquid crystal display device 24 provided with the present polarizer in such a configuration, a function of making incident light linearly polarized light is given. Similar to the liquid crystal display device 10, the retardation layers 13 a and 13 b may not be arranged depending on the type of liquid crystal compound included in the liquid crystal layer 17.

  Next, the EL display device using the polarizer will be described with reference to FIGS.

  In the EL display device 30, an organic functional layer 36 that is a light source and a cathode electrode 37 are laminated on a substrate 33 on which a pixel electrode 35 is formed. A retardation plate 32 and a polarizing plate 31 are disposed on the opposite side of the organic functional layer 36 with the substrate 33 interposed therebetween, and the polarizer 1 is used as the polarizing plate 31. By applying a positive voltage to the pixel electrode 35 and a negative voltage to the cathode electrode 37 and applying a direct current between the pixel electrode 35 and the cathode electrode 37, the organic functional layer 36 emits light. The organic functional layer 36 that is a light emitting source includes an electron transport layer, a light emitting layer, a hole transport layer, and the like. The light emitted from the organic functional layer 36 passes through the pixel electrode 35, the interlayer insulating film 34, the substrate 33, the retardation plate 32, and the polarizer 31 (the present polarizer 1). Although the organic EL display device having the organic functional layer 36 will be described, the present invention may be applied to an inorganic EL display device having an inorganic functional layer.

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

  Next, the polarizer 31 (the present polarizer 1) is provided on the surface of the substrate 33 opposite to the surface 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, and the retardation layer 32 is more preferably formed of a quarter wavelength plate. In order to provide the retardation layer 32, a laminate 45 in which the polarizer 31 (the present polarizer 1) and the retardation layer 32 are laminated in advance is prepared, and the laminate 45 is bonded to the substrate 33. Good. The outline of the manufacturing method using this laminated body 45 is shown in FIG.

  When the present polarizer 1 is used for the polarizer 31, the stacking order 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.

FIG. 6 is an enlarged cross-sectional view schematically showing a portion C in FIG. 6C1 shows that when the present polarizer 1 is used as the polarizer 31, the transparent base material 2, the alignment layer 3, the polarizing layer 4 and the protective layer 7 are arranged in this order from the retardation layer 32 side. This shows that the present polarizer 1 is provided.
Further, (C2) in FIG. 6 is provided with the present polarizer 1 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. Indicates that

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

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

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

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

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

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

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

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

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

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

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

  A desiccant 38 is disposed in the space between the cathode electrode 37 and the sealing lid 39. This is because the organic functional layer 36 is vulnerable to humidity. The desiccant 38 absorbs moisture and prevents the organic functional layer 36 from being deteriorated.

FIG. 8 is a schematic diagram illustrating a cross-sectional configuration of another aspect of the EL display device 30. This EL display device 30 has a sealing structure using a thin film sealing film 41, and can obtain emitted light from the opposite surface of the array substrate.
As the thin film sealing film 41, it is preferable to use a DLC film obtained by evaporating DLC (diamond-like carbon) on an electrolytic capacitor film. The DLC film has a characteristic that moisture permeability is extremely poor, and has high moisture-proof performance. Further, a DLC film or the like may be directly deposited on the surface of the cathode electrode 37. Further, the thin film sealing film 41 may be formed by laminating a resin thin film and a metal thin film in multiple layers.

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

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

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

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

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

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

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

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

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

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

  Electronic paper includes those displayed by molecules such as optical anisotropy and dye molecule orientation, those displayed by particles such as electrophoresis, particle movement, particle rotation, and phase change, and one end of the film moves. And the like, those displayed by molecular color development / phase change, those displayed by light absorption of molecules, and those displayed by self-emission by combining electrons and holes. More specifically, microcapsule type electrophoresis, horizontal movement type electrophoresis, vertical movement type electrophoresis, spherical twist ball, magnetic twist ball, cylindrical twist ball method, charged toner, electronic powder fluid, magnetophoretic type, magnetic thermosensitive Formula, electrowetting, light scattering (transparency / transparency change), cholesteric liquid crystal / photoconductive layer, cholesteric liquid crystal, bistable nematic liquid crystal, ferroelectric liquid crystal, dichroic dye / liquid crystal dispersion type, movable film, leuco dye And color erasing, photochromic, electrochromic, electrodeposition, flexible organic EL, and the like. The electronic paper may be used not only for personal use of text and images but also for advertisement display (signage) or the like. According to 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 alternately like a micropole method has been proposed (Japanese Patent Laid-Open No. 2002-185983), but when the optical film of the present invention is used as a polarizing film, Since patterning is easy by printing, inkjet, photolithography, etc., the manufacturing process of the display device can be shortened, and a retardation film is not required.

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

In this example, the following polymerizable liquid crystal compound was used.
Compound (1-6) (compound represented by the following formula (1-6))
Compound (1-6) was prepared according to Lub et al. Trav. Chim. It was synthesized by the method described in Pays-Bas, 115, 321-328 (1996).

(Measurement of phase transition temperature)
The phase transition temperature of the compound (1-6) was confirmed by determining the phase transition temperature of the film made of the compound (1-6). The operation is as follows.
A film made of the compound (1-6) was formed on the glass substrate on which the alignment film was formed, and the phase transition temperature was confirmed by texture observation with a polarizing microscope (BX-51, manufactured by Olympus) while heating. The film made of the compound (1-6) is heated to 120 ° C., and when the temperature is lowered, the film transitions to the nematic phase at 112 ° C., the phase transition to the smectic A phase at 110 ° C., and the smectic B phase at 94 ° C. It was confirmed that the phase transition occurred.

Compound (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 compound (1-7) was confirmed in the same manner as in the measurement of the phase transition temperature of compound (1-6). Compound (1-7) was heated to 140 ° C., and at the time of cooling, the phase transition to the nematic phase at 133 ° C., the phase transition to the smectic A phase at 118 ° C., and the phase transition to the smectic B phase at 78 ° C. It was confirmed.

Example 1
(Preparation of composition for forming polarizing layer)
The following components were mixed and stirred at 80 ° C. for 1 hour to obtain a polarizing layer forming composition.
Polymerizable liquid crystal compound; compound (1-6) 50 parts
Compound (1-7) 50 parts Dichroic dye; Azo dye (NKX2029; manufactured by Hayashibara Biochemical Laboratories) 2.5 parts Polymerization initiator;
2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one (Irgacure 369; manufactured by Ciba Specialty Chemicals) 6 parts Leveling agent;
Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie)
1.2 parts solvent; 250 parts cyclopentanone

(Measurement of phase transition temperature)
Similarly to the case of compound (1-6) and compound (1-7), the phase transition temperature of the polymerizable liquid crystal composition contained in the composition for forming a polarizing layer prepared as described above was determined. This polymerizable liquid crystal composition had a temperature transition to 120 ° C., a phase transition to a nematic phase at 112 ° C., a phase transition to a smectic A phase at 104 ° C., and a phase transition to a smectic B phase at 78 ° C. It was confirmed.

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

2. Formation of Polarizing Layer The polarizing layer-forming composition is applied onto the alignment layer of the laminate 1 by spin coating, dried by heating on a 120 ° C. hot plate for 3 minutes, and then rapidly heated to 70 ° C. The first dry film was formed on the alignment layer by cooling to a temperature showing a phase) or lower. In the first dry film, the liquid crystal state of the polymerizable liquid crystal compound contained was a smectic B phase. Next, by using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by USHIO INC.), The first dry film is irradiated with ultraviolet rays at an exposure amount of 2400 mJ / cm ² (365 nm standard). The polymerizable liquid crystal compound contained in was polymerized while maintaining the liquid crystal state of the polymerizable liquid crystal composition, and a polarizing layer was formed from the first dry film, whereby a laminate 2 was obtained. When the thickness of the polarizing layer at this time was measured with a laser microscope (OLS3000 manufactured by Olympus Corporation), it was 1.8 μm.

3. X-ray diffraction measurement The polarizing layer of the obtained laminate 2 was subjected to X-ray diffraction measurement using an X-ray diffractometer X'Pert PRO MPD (Spectris Co., Ltd.). X-rays generated under the conditions of an X-ray tube current of 40 mA and an X-ray tube voltage of 45 kV using Cu as a target are rubbed through a fixed divergence slit 1/2 ° (the rubbing direction of the alignment layer below the polarizing layer in advance) As a result of scanning and measuring in steps of 2θ = 0.01671 ° in a scanning range of 2θ = 4.0 to 40.0 °, the measurement results in the vicinity of 2θ = 20.22 °. A sharp diffraction peak (Bragg peak) having a peak half width (FWHM) of about 0.187 ° was obtained. In addition, the same result was obtained even when incident from the rubbing vertical direction. The order period (d) obtained from the peak position is about 4.39 mm, and it was found that a structure reflecting a high-order smectic phase was formed.

4). Production of the present polarizer by forming a protective layer On the polarizing layer of the laminate 2, 50 parts of dipentaerythritol hexaacrylate (Aronix M-403, polyfunctional acrylate manufactured by Toagosei Co., Ltd.), acrylate resin (Evecryl 4858 Daicel UCB Co., Ltd.) 50 parts of 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one (Irgacure 907; manufactured by Ciba Specialty Chemicals) dissolved in 250 parts of isopropanol (manufactured) The composition for forming a protective layer) is applied by spin coating, heated and dried on a hot plate at 50 ° C. for 1 minute, and then UV-irradiated using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by USHIO INC.). and by irradiating with an exposure dose 400mJ ^/ cm 2 (365nm reference), This polarizer by forming a protective layer over the polarizing layer (hereinafter, referred to as "the polarizer A".) Was prepared. It was 2.8 micrometers when the protective layer in this case was measured with the laser microscope (OLS3000 by Olympus Corporation).

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

Example 2
An experiment similar to that of Example 1 was performed except that the dichroic dye was changed from an azo dye (NKX2029; manufactured by Hayashibara Biochemical Laboratories) to an azo dye (G205; manufactured by Hayashibara Biochemical Research Laboratories). , "This polarizer B"). The phase transition behavior of the polymerizable liquid crystal composition at this time was as follows. After the temperature was raised to 120 ° C., when the temperature was lowered, the phase transitioned to the nematic phase at 112 ° C., the phase transition to the smectic A phase at 105 ° C., and the smectic B at 77 ° C. It was confirmed that the phase transition to the phase.
Table 1 shows the dichroic ratio measurement results of the obtained polarizer.

Example 3
An experiment similar to that of Example 1 was performed except that the solvent contained in the protective layer-forming composition was changed from isopropanol to ethanol to produce the present polarizer (hereinafter referred to as “present polarizer C”). Table 1 shows the dichroic ratio measurement results of the prepared polarizer.

Example 4
An experiment similar to that of Example 1 was performed except that the solvent contained in the protective layer-forming composition was changed from isopropanol to propylene glycol monomethyl ether acetate, and this polarizer (hereinafter referred to as “present polarizer D”) was used. Manufactured. Table 1 shows the dichroic ratio measurement results of the prepared polarizer.

Example 5
An experiment similar to that in Example 1 was conducted except that the solvent contained in the protective layer-forming composition was changed from isopropanol to propylene glycol monomethyl ether to produce the present polarizer (hereinafter referred to as “the present polarizer E”). did. Table 1 shows the dichroic ratio measurement results of the prepared polarizer.

Example 6
On the protective layer of the present polarizer A obtained in Example 1, a TAC (triacetyl cellulose) film was bonded via an adhesive layer formed from a pressure-sensitive adhesive (PSA). Table 1 shows the dichroic ratio measurement results of the structure thus obtained (hereinafter referred to as “the present polarizer A + TAC”).

Example 7
On the protective layer of the present polarizer B obtained in Example 2, a TAC (triacetylcellulose) film was bonded via an adhesive layer formed from a pressure-sensitive adhesive (PSA). Table 1 shows the dichroic ratio measurement results of the structure thus obtained (hereinafter referred to as “the present polarizer B + TAC”).

Example 8
The surface of the polarizing layer produced in the same manner as in Example 1 was activated by corona treatment, and a 10% by mass aqueous solution of polyvinyl alcohol (polyvinyl alcohol 1000 completely saponified type, manufactured by Wako Pure Chemical Industries, Ltd.) was added. The polarizer (hereinafter referred to as “the present polarizer F”) is formed by forming a protective layer on the polarizing layer by applying the film by a spin coating method and drying by heating on a hot plate at 80 ° C. for 1 minute. Manufactured. Table 1 shows the dichroic ratio measurement results of the prepared polarizer.

Example 9
On the polarizing layer produced in the same manner as in Example 1, the surface was activated by applying corona treatment, and a solution in which an aliphatic urethane acrylate resin was dispersed (UCECOAT 7655, manufactured by Daicel Cytec Co., Ltd.) was applied by spin coating. And this polarizer (henceforth "this polarizer G") was manufactured by heat-drying for 1 minute on a 60 degreeC hotplate, and forming a protective layer on this polarizing layer. Table 1 shows the dichroic ratio measurement results of the prepared polarizer.

Example 10
On the protective layer of the present polarizer A obtained in Example 8, a TAC (triacetyl cellulose) film was bonded via an adhesive layer formed from a pressure-sensitive adhesive (PSA). Table 1 shows the dichroic ratio measurement results of the structure thus obtained (hereinafter referred to as “the present polarizer F + TAC”).

Example 11
On the protective layer of the present polarizer A obtained in Example 9, a TAC (triacetyl cellulose) film was bonded via an adhesive layer formed from a pressure-sensitive adhesive (PSA). Table 1 shows the dichroic ratio measurement results of the structure thus obtained (hereinafter referred to as “the present polarizer G + TAC”).

（※）
ＩＰＡ ：イソプロパノール
ＥＴＡ ：エタノール
ＰＧＭＥＡ：プロピレングリコールモノメチルエーテルアセテート
ＰＧＭＥ ：プロピレングリコールモノメチルエーテル

(*)
IPA: Isopropanol ETA: Ethanol PGMEA: Propylene glycol monomethyl ether acetate PGME: Propylene glycol monomethyl ether

Evaluation Example 1 Durability Test The following aging test was performed as a durability test of the present polarizer.
The present polarizer obtained in Examples 1 and 2 and the structures obtained in Examples 6 to 7 and 10 (present polarizer A + TAC, present polarizer B + TAC or present polarizer F + TAC) were placed in a Hitachi thermostat (trade name). : EC-15HHP, manufactured by Hitachi Air Conditioning System Co., Ltd.) [Condition: Dry bulb temperature 60 ° C humidity 90% RH, or 85 ° C humidity 0%], measure the absorbance after 100 hours, and determine the dichroic ratio Asked. In this way, the dichroic ratio is measured again after the elapse of 100 hours, and the case where the initial dichroic ratio and the dichroic ratio after the lapse are not substantially changed is “g” (good), which is deteriorated. The case was judged at two levels of “b” (bad). The results are shown in Table 2.

2. Solvent Resistance Test When the polarizer is used in a liquid crystal cell, that is, in an in-cell type liquid crystal display device, a PI (polyimide) alignment film needs to be provided on the protective layer of the polarizer. An NMP (N-methyl-2-pyrrolidone) solution is often used for forming the PI alignment film. That is, this polarizer is required to have solvent resistance to NMP. Therefore, NMP was dropped on the surface of these protective layers, held for 5 minutes, and then wiped to evaluate whether the protective layer was dissolved. The evaluation results were determined at two levels, “g” (good) when no dissolution by NMP was observed, and “b” (bad) when dissolution by NMP was observed. The results are shown in Table 3.

  The polarizer of the present invention is useful for producing a liquid crystal display device, an (organic) EL display device, and a projection type liquid crystal display device.

1 Polarizer of the present invention (present polarizer)
2 Transparent substrate 3 Alignment layer 4 Polarizing layer 5 Matrix 6 Dichroic dye 7 Protective layer 10 Liquid crystal display device 11 Antireflection film 12a, 12b Polarizing film 13a, 13b Phase difference layer 14a, 14b Substrate 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 Pixel electrode 23 Spacer 24 Liquid crystal display device 30 EL display device 31 Polarizer 32 Phase difference layer 33 Substrate 34 Interlayer insulating film 35 Pixel electrode 36 Light emitting layer 37 Cathode electrode 38 Desiccant 39 Sealing lid 40 Thin film transistor 41 Rib 42 Thin film sealing film 44 EL display device 111 Light source 112 First lens array 112a Lens 113 Second lens array 114 Polarization conversion element 115 Superimposing lenses 121, 123, 132 Dichroic Over 122 reflecting mirrors 140R, 140G, 140B liquid crystal panel 142, 143 polarizing film 150 cross dichroic prism 170 the projection lens 180 Screen

Claims (12)

On a transparent substrate, an alignment layer, a polarizing layer and a protective layer are provided in this order, a polarizer,
The polarizing layer is
In a layer in which a dichroic dye is dispersed in a matrix in a smectic liquid crystal state obtained by polymerizing a polymerizable liquid crystal compound having an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group or an oxetanyl group as a polymerizable group. Yes,
The protective layer is a polarizer including a water-soluble polymer. The polymerizable liquid crystal compound has the formula (1)
^{U 1 -V 1 -W 1 -X 1} -Y 1 -X 2 -Y 2 -X 3 -W 2 -V 2 -U 2 (1)
[In Formula (1),
X ¹ , X ² and X ³ each independently represent a p-phenylene group which may have a substituent or a cyclohexane-1,4-diyl group which may have a substituent. However, at least one of X ¹ , X ² and X ³ is a p-phenylene group which may have a substituent.
Y ¹ and ^{Y 2,} independently of one _{another, -CH 2 CH 2 -, -} CH 2 O -, - COO -, - OCOO-, a single ^{bond, -N = N -, - CR} a = CR b -, - C≡C— or —CR ^a ═N— is represented. R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
U ¹ represents a hydrogen atom, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group, or an oxetanyl group.
U ² represents an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group or an oxetanyl group.
W ¹ and W ² each independently represent a single bond, —O—, —S—, —COO— or —OCOO—.
V ¹ and V ² each independently represent an optionally substituted alkanediyl group having 1 to 20 carbon atoms, and —CH ₂ — constituting the alkanediyl group is —O—, — S- or -NH- may be substituted. ]
The polarizer according to claim 1, which is a polymerizable liquid crystal compound represented by the formula: The polarizer according to claim 1 or 2, wherein the polarizing layer is a polarizing layer from which a Bragg peak is obtained in X-ray diffraction measurement. The polarizer according to any one of claims 1 to 3, wherein the polarizing layer has a thickness in a range of 0.5 to 3 µm. The polarizer according to claim 1, wherein the dichroic dye is an azo dye. The polarizer according to claim 1, wherein the polymerizable liquid crystal compound contains two or more kinds of polymerizable smectic liquid crystal compounds. The polarizer according to claim 1, wherein the protective layer is formed from a composition for forming a protective layer containing a water-soluble polymer and water. A liquid crystal display device, wherein the polarizer according to claim 1 is disposed inside a liquid crystal cell. The circularly-polarizing plate which provided the quarter wavelength plate on the said protective layer of the polarizer in any one of Claims 1-8. The circularly polarizing plate according to claim 9, wherein the ¼ wavelength plate is a wavelength plate having a characteristic that an in-plane retardation value with respect to visible light becomes smaller as the wavelength becomes shorter. An organic EL display device comprising the circularly polarizing plate according to claim 9 or 10 and an organic EL element. A step (1) of forming a laminate by providing an alignment layer on a transparent substrate;
A composition comprising a polymerizable liquid crystal compound having an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group or an oxetanyl group as a polymerizable group, a dichroic dye and a polymerization initiator on the alignment layer of the laminate. And (2) forming a first coating film on the alignment layer,
The first coating film formed in the step (2) is dried under a condition in which the polymerizable liquid crystal compound contained in the first coating film is not polymerized to form a first dry film, and the first coating film is formed. A step of forming a polarizing layer from the first dry film by polymerizing the polymerizable liquid crystal compound while maintaining the smectic liquid crystal state after the polymerizable liquid crystal compound in the dry film is in a smectic liquid crystal state ( 3) and
On the polarizing layer formed in the step (3), a protective layer composition containing a water-soluble polymer and water is applied to form a second coating film on the polarizing layer, and the second coating is applied. And a step (4) of forming a protective layer from the second coating film by drying a water-soluble polymer contained in the film.

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