KR20220114492A - Polarizing plate - Google Patents

Abstract

The present invention is to acquire a polarizing plate with improved durability of a polarizer and phase difference layer. The polarizing plate includes a polarizer containing dichroic azo pigments, a first cured product layer, a second cured product layer, and a phase difference layer including a cured product of a polymerizable liquid crystal compound, which come in contact and are stacked in order. The first cured product layer is a cured product layer of a polyvinyl alcohol-based resin composition and the second cured product layer is a cured product layer of a cationic polymerizable composition.

Description

Polarizing plate {POLARIZING PLATE}

The present invention relates to a polarizing plate, and also to an image display device including the polarizing plate.

Conventionally, in an image display apparatus, the method of suppressing the fall of visibility by reflection of extraneous light by arrange|positioning the optical laminated body which has antireflection performance on the visual recognition side of an image display panel is employ|adopted. As an optical laminate having antireflection performance, a circularly polarizing plate including a polarizer and a retardation layer is known.

When an image display apparatus is used under a harsh environment, for example, under an environment like immersion in warm water, there exists a problem that the optical characteristic of a polarizer is easy to fall. It is described by Unexamined-Japanese-Patent No. 2013-105036 that the polarizer excellent in durability is obtained by making the boric acid content in a polarizer high.

Patent Document 1: Japanese Patent Laid-Open No. 2013-105036

Moreover, the optical characteristic of a retardation layer also falls easily in a harsh environment. An object of the present invention is to provide a polarizing plate with improved durability of a polarizer and a retardation layer, and an image display device including the same.

This invention provides the polarizing plate and image display apparatus illustrated below.

[1] A polarizer containing a dichroic azo dye, a first cured material layer, a second cured material layer, and a retardation layer containing a cured product of a polymerizable liquid crystal compound are laminated in contact with each other in this order,

The first cured material layer is a cured material layer of the polyvinyl alcohol-based resin composition,

The second cured material layer is a polarizing plate that is a cured material layer of the cationically polymerizable composition.

[2] The polarizing plate according to [1], wherein the polyvinyl alcohol-based resin composition contains acetoacetyl group-modified polyvinyl alcohol.

[3] The polarizing plate according to [1] or [2], wherein the degree of saponification of the polyvinyl alcohol-based resin contained in the polyvinyl alcohol-based resin composition is 85 mol% or more and 100 mol% or less.

[4] The polarizing plate according to any one of [1] to [3], wherein the degree of polymerization of the polyvinyl alcohol-based resin contained in the polyvinyl alcohol-based resin composition is 1000 or more and 5000 or less.

[5] In any one of [1] to [4], wherein the polyvinyl alcohol-based resin composition does not contain an aldehyde compound or contains 8.0 parts by mass or less of an aldehyde compound with respect to 100 parts by mass of the polyvinyl alcohol-based resin. described polarizer.

[6] The polarizing plate according to any one of [1] to [5], wherein the cationically polymerizable composition contains an oxetane compound.

[7] The polarizing plate according to [6], wherein the cationically polymerizable composition further contains an epoxy compound.

[8] The polarizing plate according to [7], wherein the cationically polymerizable composition contains 10 parts by mass or more and 2000 parts by mass or less of the oxetane compound with respect to 100 parts by mass of the epoxy compound.

[9] The polarizing plate according to any one of [1] to [8], wherein the cationically polymerizable composition further contains a photosensitizer.

[10] The polarizing plate according to any one of [1] to [9], wherein the retardation layer includes a quarter wave plate layer.

[11] An image display device comprising the polarizing plate according to any one of [1] to [10].

ADVANTAGE OF THE INVENTION According to this invention, the polarizing plate which both durability of a polarizer and retardation layer improved, and the image display apparatus provided with this can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing which shows typically an example of the polarizing plate of this invention.

EMBODIMENT OF THE INVENTION Hereinafter, although embodiment of this invention is described, referring drawings, this invention is not limited to the following embodiment. In all the drawings below, the scales are appropriately adjusted to facilitate understanding of each component, and the scale of each component shown in the drawings and the scale of the actual component do not necessarily coincide.

<Polarizer>

The polarizing plate which concerns on this invention is demonstrated, referring FIG. The polarizing plate 100 according to the present invention includes a polarizer 10 containing a dichroic azo dye, a first cured material layer 20, a second cured material layer 30, and a cured product of a polymerizable liquid crystal compound The retardation layer 40 containing The polarizing plate 100 is, for example, a circularly polarizing plate including a linear polarizer and a retardation layer. In the present specification, the circularly polarizing plate includes an elliptically polarizing plate. The circularly polarizing plate may have an antireflection function in an image display device.

Since the dichroic azo dye contained in the polarizer has high linearity, it is suitable for production of a polarizer having excellent polarization performance, but even if a very small amount of the dye is diffused out of the polarizer, the optical properties of the polarizer may be reduced. In particular, in a high-temperature environment, this diffusion was remarkable, and there existed a problem that a polarizer deteriorated easily. A configuration in which a polarizer containing a dichroic azo dye, a first cured material layer that is a cured material layer of the polyvinyl alcohol-based resin composition, and a second cured material layer that is a cured material layer of the cationically polymerizable composition are in contact in this order The polarizing plate which has can suppress the diffusion (especially thermal diffusion) of a dichroic azo dye, and can improve durability of a polarizer. In the polarizing plate according to the present invention, the amount of change in the degree of polarization of the polarizing plate is less than 1.0, for example, even when placed in a high-temperature environment with a temperature of 85°C.

On the other hand, the retardation layer containing the hardened|cured material of a polymeric liquid crystal compound had the problem that a monomer was easy to diffuse in environments, such as high temperature and high humidity, and the retardation layer deteriorated easily. When the retardation layer containing the cured product of the polymerizable liquid crystal compound and the second cured material layer are laminated in contact with each other, diffusion of the monomer can be suppressed and the durability of the retardation layer can be improved. In the polarizing plate according to the present invention, the amount of change in the phase difference at a wavelength of 550 nm of the quarter-wave plate is less than 2.5 nm, even when placed in a high-temperature, high-humidity environment with a temperature of 65°C and a relative humidity of 90%, for example.

The optical laminate may be, for example, a rectangle in plan view, preferably a rectangle having a long side and a short side, and more preferably a rectangle. As for each layer which comprises an optical laminated body, an edge part may be R-processed, an edge part may be cut-processed, or a perforation process may be carried out.

The optical laminate can be used, for example, in an image display device or the like. The image display device is not particularly limited, and examples thereof include an organic electroluminescent (organic EL) display device, an inorganic electroluminescent (inorganic EL) display device, a liquid crystal display device, and an electroluminescent display device.

[Polarizer]

The polarizer may be a stretched film to which a dichroic azo dye is adsorbed, or a cured product of a composition containing a polymerizable liquid crystal compound and a dichroic azo dye.

As a stretched film to which a dichroic azo dye is adsorbed, for example, a polyvinyl alcohol (hereinafter, sometimes abbreviated as "PVA")-based resin film is dyed with a dichroic dye containing a dichroic azo dye, and uniaxially stretched. The obtained polarizer can be used.

Polyvinyl alcohol-type resin is obtained by saponifying polyvinyl acetate-type resin. As polyvinyl acetate-type resin, other than polyvinyl acetate which is a homopolymer of vinyl acetate, the copolymer of vinyl acetate and the other monomer copolymerizable to it is used. Examples of the other monomer copolymerizable with vinyl acetate include an unsaturated carboxylic acid-based compound, an olefin-based compound, a vinyl ether-based compound, an unsaturated sulfone-based compound, and a (meth)acrylamide-based compound having an ammonium group.

The saponification degree of polyvinyl alcohol-type resin is about 85 mol% or more and 100 mol% or less normally, Preferably it is 98 mol% or more. The polyvinyl alcohol-type resin may be modified|denatured, and polyvinyl formal, polyvinyl acetal, etc. which were modified|denatured with aldehydes can also be used. The average degree of polymerization of polyvinyl alcohol-type resin is 1000 or more and 10000 or less normally, Preferably they are 1500 or more and 5000 or less. The average degree of polymerization of polyvinyl alcohol-type resin can be calculated|required based on JISK6726 (1994). If the average degree of polymerization is less than 1000, it is difficult to obtain desirable polarization performance, and if it exceeds 10000, the film workability may be poor.

As another method of manufacturing a linear polarizing plate containing a polyvinyl alcohol-based resin film, a base film is first prepared, a solution of a resin such as a polyvinyl alcohol-based resin is applied on the base film, and the solvent is removed, such as drying. The method including the process of performing and forming a resin layer on a base film is mentioned. A primer layer can be previously formed on the surface on which the resin layer of the base film is formed. As a material of a primer layer, resin etc. which bridge|crosslinked the hydrophilic resin used for a linear polarizer are mentioned.

As a base film, For example, a cyclopolyolefin type resin film; Cellulose acetate-type resin film containing resin, such as a triacetyl cellulose and a diacetyl cellulose; Polyester-type resin film containing resin, such as a polyethylene terephthalate, a polyethylene naphthalate, and a polybutylene terephthalate; polycarbonate-based resin film; (meth)acrylic resin film; A thermoplastic resin film well-known in this field|area, such as a polypropylene resin film, is mentioned. The thickness of the base film is usually 100 µm or less, preferably 80 µm or less, more preferably 60 µm or less, still more preferably 40 µm or less, and still more preferably 30 µm or less from the viewpoint of reducing the thickness of the base film. , and is usually 5 µm or more, preferably 10 µm or more.

The hard-coat layer may be formed on the thermoplastic resin film. The hard-coat layer may be formed in one side of a thermoplastic resin film, and may be formed in both surfaces. By providing a hard-coat layer, it can be set as the thermoplastic resin film which improved hardness and scratch resistance.

Next, the amount of solvents, such as water|moisture content of a resin layer is adjusted as needed, after that, a base film and a resin layer are uniaxially stretched, Then, the resin layer is dyed with a dichroic dye, and a dichroic dye is adsorbed to a resin layer. orientate If necessary, the resin layer in which the dichroic dye is adsorbed and oriented is treated with an aqueous boric acid solution, and a washing step of washing the aqueous boric acid solution is performed. Thereby, the polarizer which is the resin layer by which the dichroic dye was adsorbed-oriented is manufactured. A well-known method can be employ|adopted for each process.

Uniaxial stretching of a base film and a resin layer may be performed before dyeing, may be performed during dyeing, may be performed during the boric acid process after dyeing|staining, and may uniaxially stretch, respectively in these several steps. A base film and a resin layer may uniaxially stretch in MD direction (film conveyance direction), in this case, uniaxial stretching may be carried out between the rolls from which circumferential speed differs, and may uniaxially stretch using a hot roll. In addition, a base film and a resin layer may uniaxially stretch in TD direction (direction perpendicular|vertical to a film conveyance direction), and in this case, a so-called tenter method can be used. In addition, the extending|stretching of a base film and a resin layer may be dry extending|stretching extending|stretching in air|atmosphere, and wet extending|stretching which extends|stretches in the state which swelled the resin layer with the solvent may be sufficient as it. In order to express the performance of a polarizer, a draw ratio is 4 times or more, It is preferable that it is 5 times or more, and 5.5 times or more are especially preferable. Although there is no upper limit in particular of a draw ratio, 8 times or less is preferable from a viewpoint of suppressing a fracture|rupture etc.

The polarizer produced by the said method may peel a base film, or may use it as a linear polarizer together with a base film. According to the said method, since a base film can be peeled, thickness reduction of a linear polarizer becomes possible.

The thickness of the polarizer containing a polyvinyl alcohol-type resin film is 2 micrometers or more and 40 micrometers or less, for example. The thickness of the polarizer may be 5 µm or more, 20 µm or less, 15 µm or less, and further 10 µm or less.

A polarizer can also be formed by apply|coating the composition containing a polymeric liquid crystal compound and a dichroic azo dye on the alignment film formed on the base film, for example, and polymerizing and hardening a polymerizable liquid crystal compound. On a base film, you may form a polarizer by apply|coating the composition containing a polymeric liquid crystal compound and a dichroic azo dye, forming a coating film, and extending|stretching this coating film with a base film. The material and thickness of the base film may be the same as the material and thickness of the aforementioned thermoplastic resin film. A polarizer may be used as a linear polarizer, without peeling and removing a base film, and it is good also as a linear polarizer by peeling and removing a base film from a polarizer.

A polymerizable liquid crystal compound is a compound which has a polymerizable reactive group and shows liquid crystallinity. A polymerizable reactive group is a group which participates in a polymerization reaction, and it is preferable that it is a photopolymerizable reactive group. The photopolymerization reactive group refers to a group capable of participating in a polymerization reaction by an active radical or an acid generated from a photopolymerization initiator. Examples of the photopolymerizable functional group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxiranyl group, and an oxetanyl group. have. Among these, acryloyloxy group, methacryloyloxy group, vinyloxy group, oxiranyl group and oxetanyl group are preferable, and acryloyloxy group is more preferable. The kind of the polymerizable liquid crystal compound is not particularly limited, and a rod-shaped liquid crystal compound, a disk-shaped liquid crystal compound, and a mixture thereof can be used. The liquid crystallinity of the polymerizable liquid crystal compound may be either a thermotropic liquid crystal or a lyotropic liquid crystal, and may be a nematic liquid crystal or a smectic liquid crystal as a normal-order structure.

A composition comprising a polymerizable liquid crystal compound and a dichroic dye, and a method for manufacturing a polarizer using the composition include Japanese Patent Laid-Open No. 2013-37353, Japanese Patent Application Laid-Open No. 2013-33249, and Japanese Patent Laid-Open No. 2017 -83843 publication etc. can be illustrated. The composition for forming a polarizer may further contain additives, such as a solvent, a polymerization initiator, a crosslinking agent, a leveling agent, antioxidant, a plasticizer, and a sensitizer, in addition to a polymerizable liquid crystal compound and a dichroic dye.

These components may use only 1 type, respectively, and may use them in combination of 2 or more type.

A polymerization initiator is a compound which can start the polymerization reaction of a polymeric liquid crystal compound, From a viewpoint of being able to start a polymerization reaction under more low-temperature conditions, a photoinitiator is preferable. Specifically, a photoinitiator capable of generating an active radical or an acid by the action of light is exemplified, and among these, a photoinitiator capable of generating a radical by the action of light is preferable. To [ content of a polymerization initiator / 100 weight part of total amounts of a polymeric liquid crystal compound ], Preferably they are 1 mass part or more and 10 mass parts or less, More preferably, they are 3 mass parts or more and 8 mass parts or less. If it exists in this range, reaction of a polymeric group will fully advance and it will be easy to stabilize the orientation state of a liquid crystal compound.

The thickness of the polarizer produced by the method mentioned above is 10 micrometers or less normally, Preferably they are 0.5 micrometer or more and 8 micrometers or less, More preferably, they are 1 micrometer or more and 5 micrometers or less.

As for the polarizer, the 1st hardened|cured material layer may be laminated|stacked with an orientation film. As an alignment film, a photo-alignment film is preferable from viewpoints, such as the precision and quality of an alignment angle, and the water resistance and flexibility of a polarizing plate. The thickness of the alignment film is preferably 10 nm or more and 5000 nm, more preferably 1000 nm or less, may be 500 nm or less, or may be 300 nm or less.

(dichroic azo dye)

As a dichroic azo dye, a monoazo dye, a bisazo dye, a trisazo dye, a tetrakis azo dye, a stilbenazo dye, etc. are mentioned, A bisazo dye and a trisazo dye are preferable, For example, Formula (I) and a compound represented by (hereinafter also referred to as "compound (I)").

K ¹ (-N=NK ² ) _p -N=NK ³ (I)

[In formula (I), K ¹ and K ³ each independently represent a phenyl group which may have a substituent, a naphthyl group which may have a substituent, or a monovalent heterocyclic group which may have a substituent. K ² represents a p-phenylene group which may have a substituent, a naphthalene-1,4-diyl group which may have a substituent, or a divalent heterocyclic group which may have a substituent. p represents the integer of 1-4. When p is an integer of ² or more, some K2 may mutually be same or different. -N=N- bonds may be substituted with -C=C-, -COO-, -NHCO-, -N=CH- bonds in the range showing absorption in the visible region.]

Examples of the monovalent heterocyclic group include a group in which one hydrogen atom has been removed from a heterocyclic compound such as quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzoimidazole, oxazole and benzoxazole. . Examples of the divalent heterocyclic group include a group obtained by removing two hydrogen atoms from the heterocyclic compound.

Substituents optionally having a phenyl group, a naphthyl group and a monovalent heterocyclic group in K ¹ and K ³ , and a p-phenylene group, a naphthalene-1,4-diyl group and a divalent heterocyclic group in K ² include, an alkyl group of 4; an alkoxy group having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, and a butoxy group; a C1-C4 fluorinated alkyl group, such as a trifluoromethyl group; cyano group; nitro group; halogen atom; A substituted or unsubstituted amino group such as an amino group, a diethylamino group, or a pyrrolidino group (a substituted amino group is an amino group having one or two C1-C6 alkyl groups, or two substituted alkyl groups having 2 to 8 carbon atoms bonded to each other refers to the amino group forming the alkanediyl group of . The unsubstituted amino group is -NH ₂ ) and the like.

Among the compounds (I), compounds represented by any one of the following formulas (I-1) to (I-8) are preferable.

[In formulas (I-1) to (I-8),

B1 to B30 are, independently of each other, 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 (the definition of a substituted amino group and an unsubstituted amino group is defined above same as), a chlorine atom or a trifluoromethyl group.

n1-n4 represent the integer of 0-3 mutually independently.

When n1 is 2 or more, a plurality of B ² may be the same as or different from each other,

When n2 is 2 or more, a plurality of B ⁶ may be the same as or different from each other,

When n3 is 2 or more, a plurality of B ⁹ may be the same as or different from each other,

When n4 is 2 or more, a plurality of B ¹⁴ may be the same as or different from each other.]

The weight average molecular weights of a dichroic azo dye are 300 or more and 2000 or less normally, Preferably they are 400 or more and 1000 or less. When the weight average molecular weight of a dichroic azo dye is below the said upper limit, a dichroic azo dye is mobile and becomes easy to diffuse out of a polarizer. Even in this case, the polarizing plate having a configuration in which the polarizer containing the dichroic azo dye and the first cured material layer, which is the cured material layer of the polyvinyl alcohol-based resin composition, contact in this order, the diffusion (particularly thermal diffusion) of the dichroic azo dye can be suppressed, and the durability of the polarizer can be improved.

When the polarizer has a polymerizable liquid crystal compound, the content of the dichroic azo dye is, for example, 0.1 parts by mass or more and 50 parts by mass or less, and preferably 0.1 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polymerizable liquid crystal compound. and more preferably 0.1 parts by mass or more and 12 parts by mass or less. When content of a dichroic dye is in this range, it is hard to disturb the orientation of a polymeric liquid crystal compound, and the polarizer which has a high degree of orientation order can be obtained.

[First cured material layer]

A 1st hardened|cured material layer is a hardened|cured material layer of a polyvinyl alcohol-type resin composition. The 1st hardened|cured material layer which is a hardened|cured material layer of a polyvinyl alcohol-type resin composition can prevent the diffusion of a dichroic azo dye from a polarizer. The 1st hardened|cured material layer which is a hardened|cured material layer of a polyvinyl alcohol-type resin composition is excellent also in heat resistance while protecting the surface of a polarizer. A 1st hardened|cured material layer has adhesiveness with respect to a polarizer normally.

The polyvinyl alcohol-based resin contained in the polyvinyl alcohol-based resin composition includes, in addition to partially saponified polyvinyl alcohol and fully saponified polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, methylol group-modified polyvinyl alcohol, You may also contain modified polyvinyl alcohol-type resin, such as amino group modified polyvinyl alcohol. It is preferable that polyvinyl alcohol-type resin contained in a polyvinyl alcohol-type resin composition contains acetoacetyl group-modified polyvinyl alcohol from a viewpoint of suppressing deterioration of a polarizer. A commercially available polyvinyl alcohol-type resin may be used for the polyvinyl alcohol-type resin contained in a polyvinyl alcohol-type resin composition. Commercially available products include, for example, "PVA-403", which is a partially saponified polyvinyl alcohol sold by Kuraray Co., Ltd., "KL-506" and "KL-318", which are carboxyl group-modified partially saponified polyvinyl alcohol, sold by Mitsubishi Chemical Co., Ltd. acetoacetyl group-modified partially saponified polyvinyl alcohol "Z-100", "Z-200", "Z-300", etc. are mentioned.

The degree of saponification of the polyvinyl alcohol-based resin contained in the polyvinyl alcohol-based resin composition is usually 85 mol% or more and 100 mol% or less, preferably 90 mol% or more, 95 mol% or more, and 98 mol% It may be more than

The average polymerization degree of the polyvinyl alcohol-type resin contained in the polyvinyl alcohol-type resin composition is 1000 or more and 5000 or less normally, Preferably they are 1500 or more and 3000 or less, 2000 or less may be sufficient, and 1500 or less may be sufficient as it. When an average degree of polymerization exists in this range, deterioration of a polarizer can be suppressed favorably.

Content of the polyvinyl alcohol-type resin contained in the polyvinyl alcohol-type resin composition with respect to the mass of the solid content of a polyvinyl alcohol-type resin composition, Preferably it is 85 mass % or more, More preferably, it is 90 mass % or more, More preferably preferably 95% by mass or more. All the solid content of the polyvinyl alcohol-type resin composition may be polyvinyl alcohol-type resin (that is, 100 mass %). The solid content of the polyvinyl alcohol-based resin composition means the total amount of components excluding the solvent from the polyvinyl alcohol-based resin composition when the solvent is contained in the polyvinyl alcohol-based resin composition.

Since the applicability|paintability and handleability at the time of producing the hardened|cured material of a polyvinyl alcohol-type resin composition become favorable, it is preferable that a polyvinyl alcohol-type resin composition contains a solvent. Examples of the solvent in the polyvinyl alcohol-based resin composition include water or a mixed solvent of water and a hydrophilic organic solvent (eg, alcohol solvent, ether solvent, ester solvent, etc.). When a polyvinyl alcohol-type resin composition contains a solvent, the solid content becomes like this. Preferably they are 1 mass % or more and 30 mass % or less, More preferably, they are 2 mass % or more and 10 mass % or less.

The polyvinyl alcohol-based resin composition may contain additives such as a stabilizer, an antioxidant, an antistatic agent, a ultraviolet absorber, a surface conditioner, and a crosslinking agent, if necessary. An additive can be used individually or in combination of 2 or more types. To [ content of an additive / mass of solid content of a polyvinyl alcohol-type resin composition ], Preferably it is about 0.1 mass % or more and 10 mass % or less.

Examples of the crosslinking agent include an amine compound, an aldehyde compound, a methylol compound, a water-soluble epoxy resin, an isocyanate compound, and a polyvalent metal salt. When a polyvinyl alcohol-type resin is used as an adhesive component, an aldehyde compound including glyoxal, a methylol compound including methylolmelamine, a water-soluble epoxy resin, etc. can be used as a crosslinking agent. The water-soluble epoxy resin is, for example, a polyamide epoxy obtained by reacting epichlorohydrin with a polyamide polyamine that is a reaction product of a polyalkylene polyamine such as diethylenetriamine and triethylenetetramine and a dicarboxylic acid such as adipic acid. It may be resin. As an example of the commercial item of a water-soluble epoxy resin, there exists "Sumirezu Resin (trademark) 650(30)" sold by Daoka Chemical Industry Co., Ltd.

The polyvinyl alcohol-based resin composition may not contain a crosslinking agent. In the polyvinyl alcohol-based resin composition, from the viewpoint of suppressing deterioration of the polarizer, the content of the aldehyde compound is preferably 8.0 parts by mass or less, and more preferably 5.0 parts by mass or less with respect to 100 parts by mass of the polyvinyl alcohol-based resin. , may not contain an aldehyde compound.

A polyvinyl alcohol-type resin composition can be prepared by melt|dissolving a polyvinyl alcohol-type resin and an additive etc. in a solvent as needed. The 1st hardened|cured material layer which is a hardened|cured material layer of a polyvinyl alcohol-type resin composition can be obtained by apply|coating a polyvinyl alcohol-type resin composition on one surface of a polarizer, and drying off a solvent.

The thickness of the 1st hardened|cured material layer becomes like this. Preferably they are 0.1 micrometer or more and 10 micrometers or less, More preferably, they are 0.3 micrometer or more and 2 micrometers or less. While the diffusion of the dichroic dye from a polarizer is effectively suppressed as the thickness of a 1st hardened|cured material layer is in the said range, thickness reduction of a polarizing plate becomes possible.

[phase difference layer]

The number of retardation layers may be one, and two or more layers may be sufficient as them. The retardation layer may have the base film which supports the retardation layer, the adhesive layer which bonds several retardation layers, etc. The retardation layer may further include an alignment film. The retardation layer preferably includes a quarter wave plate layer, and may further include at least one of a half wave plate layer and a positive C layer. When the retardation layer includes the 1/2 wave plate layer, the 1/2 wave plate layer and the 1/4 wave plate layer are sequentially stacked from the linear polarizer side. When the retardation layer includes the positive C layer, the quarter wave plate layer and the positive C layer may be laminated in this order from the linear polarizer side, or the positive C layer and the quarter wave plate layer may be laminated in this order from the linear polarizer side . The thickness of the retardation layer is, for example, 0.1 µm or more and 10 µm or less, preferably 0.5 µm or more and 8 µm or less, and more preferably 1 µm or more and 6 µm or less.

The retardation layer contains a cured product of a polymerizable liquid crystal compound. A retardation layer can be formed by apply|coating and hardening the composition containing a polymeric liquid crystal compound to a base film. You may form an orientation film between a base film and an application layer. The material and thickness of the base film may be the same as the material and thickness of the thermoplastic resin film. The retardation layer may be inserted into a polarizing plate in the form which has an orientation film and a base film. It is preferable that the surface which opposes a polarizer among retardation layers is a layer containing the hardened|cured material of a polymeric liquid crystal compound. The surface of the layer in which retardation is expressed may be sufficient as the surface which opposes the polarizer of a phase difference layer, and an alignment film may be sufficient as it.

The retardation layer may also contain the layer formed from the resin film other than the layer containing the hardened|cured material of a polymeric liquid crystal compound. As a resin film, the above-mentioned thermoplastic resin film may be sufficient.

The liquid crystal layer which expresses a phase difference can be formed using a well-known liquid crystal compound. The kind of liquid crystal compound contained in the composition containing the polymerizable liquid crystal compound is not particularly limited, and a rod-shaped liquid crystal compound, a disk-shaped liquid crystal compound, and a mixture thereof may be used. The composition containing the polymerizable liquid crystal compound may also contain a polymer liquid crystal compound. As a liquid crystal compound, for example, Japanese Patent Application Laid-Open No. 11-513019, Japanese Patent Application Laid-Open No. 2005-289980, Japanese Patent Application Laid-Open No. 2007-108732, Japanese Patent Application Laid-Open No. 2010-244038, Japanese Patent Laid-Open No. 2010-31223 Publication, Japanese Patent Laid-Open No. 2010-270108, Japanese Patent Laid-Open No. 2011-6360, Japanese Patent Laid-Open No. 2011-207765, Japanese Patent Laid-Open No. 2016-81035, International Publication No. 2017 /043438 and the liquid crystal compound of Unexamined-Japanese-Patent No. 2011-207765 are mentioned.

The composition containing a polymerizable liquid crystal compound may contain a polymerization initiator, a polymerizable monomer, surfactant, a solvent, a close_contact|adherence improving agent, a plasticizer, an aligning agent, etc. other than a liquid crystal compound. As a coating method of the composition containing a polymeric liquid crystal compound, well-known methods, such as a die-coating method, are mentioned. As a hardening method of the composition containing a polymeric liquid crystal compound, well-known methods, such as irradiating an active energy ray (for example, ultraviolet-ray), are mentioned.

The polarizing plate in which the polarizer and the retardation layer are arranged so that the absorption axis of the polarizer and the slow axis of the retardation layer are at a predetermined angle, that is, can function as a circular polarizing plate having an antireflection function. When the retardation layer includes a quarter wave plate layer, an angle between the absorption axis of the polarizer and the slow axis of the quarter wave plate layer may be 45°±10°. The retardation layer may have forward wavelength dispersion and may have reverse wavelength dispersion. The quarter wave plate layer preferably has reverse wavelength dispersion.

The alignment film has an alignment regulating force that aligns the polymerizable liquid crystal compound contained in the liquid crystal layer expressing the retardation formed on the alignment film in a desired direction. Examples of the alignment film include an alignment polymer film formed of an alignment polymer, a photo alignment polymer film formed of a photo alignment polymer, and a groove alignment film having a concave-convex pattern or a plurality of grooves on the surface of the film. The thickness of the alignment film is usually 0.01 µm or more and 10 µm or less, and preferably 0.01 µm or more and 5 µm or less.

An orientation polymer film can apply|coat the composition which melt|dissolved the orientation polymer in the solvent to a base film, remove a solvent, and can perform a rubbing process as needed, and can form it. The orientation regulating force can be arbitrarily adjusted according to the surface state of the orientation polymer or the rubbing conditions.

A photo-alignment polymer film can be formed by apply|coating the composition containing the polymer or monomer which has a photoreactive group, and a solvent to a base film, and irradiating polarized light. In this case, the orientation regulating force can be arbitrarily adjusted according to the polarized light irradiation conditions with respect to a photo-alignment polymer, etc.

The groove alignment film is, for example, a method of forming a concave-convex pattern by performing exposure and development through an exposure mask having a pattern-shaped slit on the surface of the photosensitive polyimide film; A method of forming an uncured film, transferring the film to a base film and curing it, forming an uncured layer of an active energy ray-curable resin on the base film, and pressing a roll-shaped disk having irregularities on this layer, etc. It can be formed by a method of hardening by forming irregularities.

[Second Cured Material Layer]

The second cured material layer is a cured material layer of the cationically polymerizable composition. A 2nd hardened|cured material layer has adhesiveness with a 1st hardened|cured material layer, and adhesiveness with retardation layer normally. The second cured material layer 30 may bond the adjacent first cured material layer 20 and the retardation layer 40 . The 2nd hardened|cured material layer which is a hardened|cured material layer of a cationically polymerizable composition can prevent the diffusion of the unpolymerized monomer from the retardation layer.

The 2nd hardened|cured material layer which is a hardened|cured material layer of a cationically polymerizable composition is excellent also in water resistance while protecting the surface of retardation layer. When a retardation layer is bonded to a polarizer or a 1st hardened|cured material layer by an adhesive layer or a radically polymerizable 2nd hardened|cured material layer, it is difficult to suppress the diffusion of the monomer from a retardation layer. Since the polyvinyl alcohol-based resin excellent in barrier properties of the dichroic dye and unpolymerized monomers can be protected by the hydrophobic cationically polymerizable resin, the first cured material layer, which is the cured material layer of the polyvinyl alcohol-based resin composition, When the 2nd hardened|cured material layer which is a hardened|cured material layer of a cationically polymerizable composition contacts and laminates|stacks, durability of a polarizer can be improved more and the thinned polarizing plate can be obtained.

The cationically polymerizable compound contained in the cationically polymerizable composition refers to a compound or oligomer that is cured by a cationic polymerization reaction proceeding by irradiation or heating of active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays, and epoxy compounds, oxetane A compound, a vinyl compound, etc. can be illustrated. These polymeric compounds may be used independently and may be used in combination of 2 or more type. The cationically polymerizable composition may contain the radically polymerizable compound in addition to the cationically polymerizable compound as a polymerizable compound. A radically polymerizable compound is a compound which can initiate a polymerization reaction with the radical species which generate|occur|produced from the photoradical polymerization initiator by irradiation of light, for example.

To [ content of the cationically polymerizable compound contained in a cationically polymerizable composition / 100 mass parts of total mass of a cationically polymerizable composition ], Preferably 80 mass parts or more and 100 mass parts or less, More preferably, 90 mass parts or more and 99.5 mass It is part or less, More preferably, it is 95 mass parts or more and 99 mass parts or less. When content of a cationically polymerizable compound exists in this range, it is excellent in water resistance, and the 2nd hardened|cured material layer excellent also in the diffusion prevention effect to the outside of a polarizer of a dichroic dye can be obtained.

The cationically polymerizable composition preferably contains a polymerizable compound having a cyclic ether structure as the polymerizable compound. Examples of the cyclic ether structure include an oxirane ring, an oxetane ring, a tetrahydrofuran ring, and a tetrahydropyran ring. Especially, it is preferable to contain the polymeric compound which has a C2-C4 cyclic ether structure from a viewpoint of the diffusion suppression and water resistance of the monomer from retardation layer, and it is more preferable to contain an oxetane compound.

An oxetane compound is a compound which has one or more oxetanyl groups (oxetane ring) in a molecule|numerator, and any of an aliphatic compound, an alicyclic compound, or an aromatic compound may be sufficient as it. Examples of the oxetane compound having one oxetanyl group include 3-ethyl-3-hydroxymethyloxetane, 2-ethylhexyloxetane, 3-ethyl-3-(phenoxymethyl)oxetane, 3-(cyclo Hexyloxy)methyl-3-ethyloxetane etc. are mentioned. Further, examples of the oxetane compound having two or more oxetanyl groups include 1,4-bis[{(3-ethyloxetan-3-yl)methoxy}methyl]benzene (“xylylenebisoxetane”). ), bis(3-ethyl-3-oxetanylmethyl)ether, and the like. These oxetane compounds may be used independently and may be used in combination of 2 or more type. An oxetane compound may be used as a main component of a cationically polymerizable compound, and may be used together with an epoxy compound.

It is preferable that an oxetane compound contains the oxetane compound which has two or more oxetanyl groups in a molecule|numerator. By including such an oxetane compound, a high-density cured product having a high crosslinking density can be obtained, effectively suppressing diffusion of the dichroic dye from the polarizer in combination with the first cured material layer, and improving optical performance over time. A polarizing plate in which a change hardly occurs can be obtained.

The content of the oxetane compound may be, for example, 10 parts by mass or more, preferably 30 parts by mass or more, more preferably 40 parts by mass or more with respect to 100 parts by mass of the total amount of all polymerizable compounds contained in the cationically polymerizable composition. , More preferably, it is 45 mass parts or more, Especially preferably, it is 50 mass parts or more. When the content of the oxetane compound is equal to or greater than the lower limit, the second cured material layer has more excellent heat resistance and heat-and-moisture resistance, so that in combination with the first cured material layer, the water resistance, heat resistance, and heat-and-moisture resistance of the polarizing plate can be effectively improved. have. Thereby, it is possible to obtain a polarizing plate in which a change in optical performance with time does not easily occur. To [ content of an oxetane compound / 100 mass parts of total amounts of all the polymeric compounds contained in a cationically polymerizable composition ], Preferably it is 90 mass parts or less, More preferably, it is 85 mass parts or less, More preferably, it is 80 mass parts. is below. In addition, the content of the oxetane compound may be a combination of the above-mentioned lower limit and upper limit, with respect to 100 parts by mass of the total amount of all polymerizable compounds contained in the cationically polymerizable composition, preferably 30 parts by mass or more and 90 parts by mass or less, More preferably, they are 40 mass parts or more and 85 mass parts or less. The content of the oxetane compound is, for example, 25 parts by mass or more, preferably 35 parts by mass or more, more preferably 40 parts by mass or more, for example, 100 parts by mass or less with respect to 100 parts by mass of the total amount of the cationically polymerizable composition. and preferably 90 parts by mass or less, more preferably 85 parts by mass or less.

It is preferable that a cationically polymerizable composition further contains an epoxy compound in addition to an oxetane compound as a polymeric compound. An epoxy compound is one or more in a molecule|numerator, Preferably it is a compound which has two or more epoxy groups. The cationically polymerizable composition preferably contains 10 parts by mass or more and 2000 parts by mass or less of the oxetane compound with respect to 100 parts by mass of the epoxy compound, more preferably 30 parts by mass or more and 1000 parts by mass or less, further preferably 30 mass parts or more and 500 mass parts are included.

An epoxy compound may be used individually by 1 type, and may use 2 or more types together. As an epoxy compound, an alicyclic epoxy compound, an aromatic epoxy compound, a hydrogenated epoxy compound, an aliphatic epoxy compound, etc. are mentioned. Especially, from a viewpoint of weather resistance, a cure rate, and adhesiveness, it is preferable that an epoxy compound contains an alicyclic epoxy compound or an aliphatic epoxy compound, and it is more preferable that an alicyclic epoxy compound is included.

An alicyclic epoxy compound is a compound which has one or more epoxy groups couple|bonded with the alicyclic ring in a molecule|numerator, Preferably it has two or more epoxy groups couple|bonded with the alicyclic ring in a molecule|numerator. "The epoxy group couple|bonded with the alicyclic ring" means the oxygen atom -O- of bridge|crosslinking in the structure represented by following formula (II). In following formula (I), m is an integer of 2-5.

The compound in which the group of the form in which one or several hydrogen atoms were removed in (CH2) _m in the said Formula ( _II ) is couple|bonded with another chemical structure may become an alicyclic epoxy compound. (CH ₂ ) One or more hydrogen atoms in _m may be suitably substituted with a straight-chain alkyl group such as a methyl group or an ethyl group.

From the viewpoint of increasing the glass transition temperature of the cured product, having an epoxycyclopentane structure [where m = 3 in the above formula (II)] or an epoxycyclohexane structure [where m = 4 in the above formula (II)] An alicyclic epoxy compound is preferable, and the alicyclic diepoxy compound represented by a following formula (IIA) is more preferable. The glass transition temperature of the 2nd hardened|cured material layer which is a hardened|cured material layer of the cationically polymerizable composition containing the alicyclic diepoxy compound represented by following formula (IIA) becomes high, and can suppress the diffusion of the pigment|dye at high temperature.

In formula (IIA), R ¹ and R ² each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and when the alkyl group has 3 or more carbon atoms, it may have an alicyclic structure. The alkyl group having 1 to 6 carbon atoms may be a straight-chain or branched alkyl group, and examples of the alkyl group having an alicyclic structure include a cyclopropyl group, a cyclobutyl group, and a cyclopentyl group.

In the formula (IIA), X represents an oxygen atom, an alkanediyl group having 1 to 6 carbon atoms, or a group represented by any one of the following formulas (IIa) to (IId). Examples of the alkanediyl group having 1 to 6 carbon atoms include a methylene group, an ethylene group, and a propane-1,2-diyl group.

When X in formula (IIA) is a group represented by any one of formulas (IIa) to (IId), Y ¹ to Y ⁴ in each formula are each independently an alkanediyl group having 1 to 20 carbon atoms, and the alkanediyl group When carbon number is 3 or more, you may have an alicyclic structure. a and b each independently represent the integer of 0-20.

As an alicyclic epoxy compound, the compound of the following A-M is mentioned, for example. In addition, formulas A to M shown in the following paragraphs correspond to compounds A to M, respectively.

A: 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate,

B: 3,4-epoxy-6-methylcyclohexylmethyl 3,4-epoxy-6-methylcyclohexanecarboxylate;

C: ethylenebis (3,4-epoxycyclohexanecarboxylate),

D: bis (3,4-epoxycyclohexylmethyl) adipate,

E: bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate,

F: diethylene glycol bis (3,4-epoxycyclohexyl methyl ether),

G: ethylene glycol bis (3,4-epoxycyclohexyl methyl ether),

H: 2,3,14,15-diepoxy-7,11,18,21-tetraoxatrispiro[5.2.2.5.2.2]henicosan,

I: 3-(3,4-epoxycyclohexyl)-8,9-epoxy-1,5-dioxaspiro[5.5]undecane,

J: 4-vinylcyclohexene dioxide,

K: limonene dioxide,

L: bis (2,3-epoxycyclopentyl) ether,

M: dicyclopentadiene dioxide.

From the viewpoint of easy availability, the alicyclic epoxy compound is preferably 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate. Moreover, the 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol is preferable from the viewpoint of being able to effectively suppress the diffusion of the dye. .

An alicyclic epoxy compound may be used individually by 1 type of alicyclic epoxy compound, and may be used in combination of different multiple types.

To [ content of an alicyclic epoxy compound / 100 mass parts of total amounts of all the polymeric compounds contained in a cationically polymerizable composition ], Preferably it is 1 mass part or more and 80 mass parts or less, More preferably, it is 3 mass parts or more and 70 mass parts. Hereinafter, more preferably, they are 3 mass parts or more and 60 mass parts or less. When the content of the alicyclic epoxy compound is within this range, curing by irradiation of active energy rays such as ultraviolet rays proceeds rapidly, and the cured material layer (second cured material layer) of sufficient hardness is excellent in heat resistance and heat-and-moisture resistance. ) can be formed.

An aliphatic epoxy compound is a compound which has at least 1 epoxy ring couple|bonded with an aliphatic carbon atom in a molecule|numerator, Preferably it has two or more epoxy rings in a molecule|numerator. The aliphatic epoxy compound has, for example, at least one oxirane ring (3-membered cyclic ether) bonded to an aliphatic carbon atom in the molecule, and preferably has two or more. Examples of the aliphatic epoxy compound include monofunctional epoxy compounds such as butyl glycidyl ether and 2-ethylhexyl glycidyl ether; Bifunctional epoxy compounds such as 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, and neopentyl glycol diglycidyl ether; trifunctional or more than trifunctional epoxy compounds such as trimethylolpropane triglycidyl ether and pentaerythritol tetraglycidyl ether; There are epoxy compounds having one epoxy group directly bonded to an alicyclic ring and an oxirane ring bonded to an aliphatic carbon atom, such as 4-vinylcyclohexene dioxide and limonene dioxide.

From the viewpoint of obtaining a cationically polymerizable composition that is low in viscosity and easy to apply, a bifunctional epoxy compound having two oxirane rings bonded to aliphatic carbon atoms in the molecule, represented by the following formula (III) (“aliphatic”) Also referred to as "diepoxy compound") is preferred.

[In formula (III), Z is an alkylene group having 1 to 9 carbon atoms, an alkylidene group having 3 or 4 carbon atoms, a divalent alicyclic hydrocarbon group, or a formula -C _m H _2m -Z ¹ -C _n H _2n - The indicated divalent group is shown. -Z ¹ - represents -O-, -CO-O-, -O-CO-, -SO ₂ -, -SO- or CO-, and m and n each independently represent an integer of 1 or more. However, the sum of m and n is 9 or less.

The divalent alicyclic hydrocarbon group may be, for example, a divalent alicyclic hydrocarbon group having 4 to 8 carbon atoms, and examples thereof include a divalent residue represented by the following formula (IIIA).

Specific examples of the compound represented by formula (III) include diglycidyl ether of alkanediol; diglycidyl ether of oligoalkylene glycol up to about 4 repetitions; Diglycidyl ether of alicyclic diol, etc. are mentioned.

Examples of the diol (glycol) capable of forming the aliphatic diepoxy compound represented by the formula (III) include ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, and 2-butyl- 2-ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl- 1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5- alkanediols such as heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, and 1,9-nonanediol; oligoalkylene glycols such as diethylene glycol, triethylene glycol, tetraethylene glycol, and dipropylene glycol; Alicyclic diols, such as cyclohexanediol and cyclohexane dimethanol, etc. are mentioned.

From the viewpoint of obtaining a cationically polymerizable composition that has a low viscosity and is easy to apply, examples of the aliphatic epoxy compound include 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, and neopentyl glycol diglycol. It is preferable to include cidyl ether. From the viewpoint of maintaining optical performance, 1,6-hexanediol diglycidyl ether and pentaerythritol polyglycidyl ether are preferable. As an aliphatic epoxy compound, 1 type of aliphatic epoxy compound may be used independently and you may use it combining different multiple types.

When the cationically polymerizable composition contains an aliphatic epoxy compound, the content of the aliphatic epoxy compound may be, for example, 1 part by mass or more and 90 parts by mass or less with respect to 100 parts by mass of the total amount of all polymerizable compounds contained in the cationically polymerizable composition, , Preferably 1 mass part or more and 40 mass parts or less, More preferably 3 mass parts or more and 30 mass parts or less, More preferably, 5 mass parts or more and 20 mass parts or less, Especially preferably, 7 mass parts or more and 15 mass parts. is below. When content of an aliphatic epoxy compound exists in this range, a viscosity is low and it can be set as the cationically polymerizable composition which is easy to apply|coat.

An aromatic epoxy compound is a compound which has an aromatic ring and an epoxy group in a molecule|numerator. Specific examples thereof include bisphenol-type epoxy compounds or oligomers thereof, such as diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, and diglycidyl ether of bisphenol S; Novolak-type epoxy resins, such as a phenol novolak epoxy resin, a cresol novolak epoxy resin, and a hydroxybenzaldehyde phenol novolak epoxy resin; Polyfunctional epoxy compounds such as glycidyl ether of 2,2',4,4'-tetrahydroxydiphenylmethane and glycidyl ether of 2,2',4,4'-tetrahydroxybenzophenone ; and polyfunctional epoxy resins such as epoxidized polyvinyl phenol.

From the viewpoint of reducing the viscosity of the cationically polymerizable composition, aromatic epoxy compounds are glycidyl ethers of phenols, glycidyl ethers of aromatic compounds having two or more alcoholic hydroxyl groups, glycidyl ethers of polyhydric phenols, benzoic acids It is preferable to contain at least 1 sort(s) selected from the group of the glycidyl ester of glycidyl ester, the glycidyl ester of polybasic acids, styrene oxide, or the epoxidation product of divinylbenzene. From the viewpoint of improving the curability of the cationically polymerizable composition, the aromatic epoxy compound preferably has an epoxy equivalent of 80 to 500. As an aromatic epoxy compound, 1 type of aromatic epoxy compound may be used independently, and different multiple types may be combined and used for it.

As the aromatic epoxy compound, commercially available products can be used, for example, denacol EX-121, denacol EX-141, denacol EX-142, denacol EX-145, denacol EX-146, denacol EX-147, denacol EX-147, and denacol EX-147. Cole EX-201, Denacol EX-203, Denacol EX-711, Denacol EX-721, On-Coat EX-1020, On-Coat EX-1030, On-Coat EX-1040, On-Coat EX-1050, On-Coat EX -1051, Oncoat EX-1010, Oncoat EX-1011, Oncoat 1012 (above, manufactured by Nagase Chemtex); Ogsol PG-100, Ogsol EG-200, Ogsol EG-210, Ogsol EG-250 (above, manufactured by Osaka Gas Chemicals); HP4032, HP4032D, HP4700 (above, manufactured by DIC); ESN-475V (manufactured by Shin-Nitetsu Sumikin Chemical Co., Ltd.); Epicoat YX8800, jER828EL (manufactured by Mitsubishi Chemical Corporation); Mapproof G-0105SA, Mapproof G-0130SP (manufactured by Nichiyu Corporation); Epiclone N-665, Epiclone HP-7200 (above, manufactured by DIC); EOCN-1020, EOCN-102S, EOCN-103S, EOCN-104S, XD-1000, NC-3000, EPPN-501H, EPPN-501HY, EPPN-502H, NC-7000L (above, manufactured by Nippon Kayaku Co., Ltd.); Adeca Glycirol ED-501, Adeca Glycirol ED-502, Adeca Glycirol ED-509, Adeca Glycirol ED-529, Adeca Resin EP-4000, Adeka Resin EP-4005, Adeka Resin EP-4100, Adeka Resin EP-4901 (above, manufactured by ADEKA); TECHMORE VG-3101L, EPOX-MKR710, EPOX-MKR151 (above, the PRINTEC company make), etc. are mentioned.

When a cationically polymerizable composition contains an aromatic epoxy compound, a cationically polymerizable composition becomes hydrophobic resin, and the hardened|cured material layer (2nd hardened|cured material layer) obtained by this also becomes hydrophobic. For this reason, penetration of the water|moisture content from the outside can be prevented under high temperature, high humidity, and the movement of the dichroic dye contained in a polarizer can be suppressed effectively.

To [ content of an aromatic epoxy compound / 100 mass parts of total amounts of all the polymeric compounds contained in a cationically polymerizable composition ], Preferably they are 1 mass part or more and 70 mass parts or less, More preferably, they are 5 mass parts or more and 60 mass parts. It is below, More preferably, they are 7 mass parts or more and 55 mass parts or less, Especially preferably, they are 10 mass parts or more and 50 mass parts or less. When content of an aromatic epoxy compound exists in this range, the hydrophobicity of a 2nd hardened|cured material layer can be improved, and the diffusion of the dichroic dye out of the polarizer in high-temperature, high-humidity conditions can be suppressed more effectively.

The hydrogenated epoxy compound is a glycidyl ether of a polyol having an alicyclic ring, and a nuclear-hydrogenated polyhydroxy compound obtained by selectively hydrogenating an aromatic polyol to an aromatic ring under pressure in the presence of a catalyst is glycidyl It may be etherified. Specific examples of the aromatic polyol include bisphenol-type compounds such as bisphenol A, bisphenol F, and bisphenol S; novolak-type resins such as phenol novolac resin, cresol novolak resin, and hydroxybenzaldehyde phenol novolak resin; and polyfunctional compounds such as tetrahydroxydiphenylmethane, tetrahydroxybenzophenone and polyvinylphenol. It can be set as glycidyl ether by making epichlorohydrin react with the alicyclic polyol obtained by hydrogenating the aromatic ring of an aromatic polyol. As a preferable thing among a hydrogenation epoxy compound, the diglycidyl ether of hydrogenated bisphenol A is mentioned.

The cationically polymerizable composition may further contain other curable compounds other than the above. Specific examples of the other curable compound are cationically polymerizable compounds other than those described above, such as a lactone compound, a cyclic acetal compound, a cyclic thioether compound, and a spiroorthoester compound.

It is preferable that a cationically polymerizable composition contains the polymerization initiator for starting superposition|polymerization. A photoinitiator may be sufficient as a polymerization initiator, and a thermal polymerization initiator may be sufficient as it. For example, when a cationically polymerizable composition contains an oxetane compound, an epoxy compound, etc. as a polymeric compound, it is preferable to use a photocationic polymerization initiator for a polymerization initiator.

A photocationic polymerization initiator generates a cationic species or a Lewis acid by irradiation of active energy rays, such as a visible ray, an ultraviolet-ray, an X-ray, or an electron beam, and initiates the polymerization reaction of a cationically polymerizable compound. Since a photocationic polymerization initiator acts catalytically with light, even if it mixes with a polymeric compound, it is excellent in storage stability and workability|operativity. Examples of the compound that generates cationic species or Lewis acid upon irradiation with active energy ray include onium salts such as aromatic iodonium salts and aromatic sulfonium salts, aromatic diazonium salts, and iron-arene complexes.

The aromatic iodonium salt is a compound having a diaryliodonium cation, and examples of the cation include a diphenyliodonium cation typically.

An aromatic sulfonium salt is a compound having a triarylsulfonium cation, and examples of the cation include a triphenylsulfonium cation and a 4,4'-bis(diphenylsulfonio)diphenylsulfide cation. have. An aromatic diazonium salt is a compound which has a diazonium cation, and a benzenediazonium cation is typically mentioned as the cation. The iron-arene complex is typically a cyclopentadienyl iron(II) arene cation complex salt.

The cation is paired with an anion to constitute a photocationic polymerization initiator. Examples of the anions constituting the photocationic polymerization initiator include special phosphorus anion [(Rf)nPF6-n]-, hexafluorophosphate anion PF6-, hexafluoroantimonate anion SbF6-, pentafluorohydroxyantimonate anion SbF5(OH)-, hexafluoroacetate anion AsF6-, tetrafluoroborate anion BF4-, tetrakis(pentafluorophenyl)borate anion B(C6F5)4-, etc. are mentioned. Among them, it is preferable that the photocationic polymerization initiator is a special phosphorus anion [(Rf)nPF6-n]- or hexafluorophosphate anion PF6- from the viewpoint of the curability of the polymerizable compound and the safety of the obtained second cured product layer. .

A photocationic polymerization initiator may be used individually by 1 type, and may be used in combination of different multiple types. Among them, aromatic sulfonium salts are preferable because they have ultraviolet absorption characteristics even in a wavelength region of around 300 nm, so they are excellent in curability, and a cured product having good mechanical strength and adhesive strength can be obtained.

Content of the polymerization initiator in a cationically polymerizable composition is 0.5 mass part or more and 10 mass parts or less normally with respect to 100 mass parts of polymeric compounds, Preferably it is 6 mass parts or less, More preferably, it is 3 mass parts or less. . When content of a polymerization initiator is in this range, a polymeric compound can fully be hardened and high mechanical strength and adhesive strength can be provided to the hardened|cured material layer comprised from the hardened|cured material obtained.

The cationically polymerizable composition may contain additives generally used in curable compositions as needed. Such additives include, for example, ion trapping agents, antioxidants, chain transfer agents, polymerization accelerators (polyols, etc.), sensitizers, sensitizers, light stabilizers, tackifiers, thermoplastic resins, fillers, flow regulators, plasticizers, defoamers, A leveling agent, a silane coupling agent, a pigment|dye, an antistatic agent, a ultraviolet absorber, etc. are mentioned.

As a sensitizer, a photosensitizer is mentioned, for example. A photosensitizer is a compound which shows maximum absorption in the wavelength longer than the maximum absorption wavelength which a photocationic polymerization initiator shows, and accelerates|stimulates the polymerization initiation reaction by a photocationic polymerization initiator. Moreover, a photosensitizer adjuvant is a compound which accelerates|stimulates the action|action of a photosensitizer further. By mix|blending a photosensitizer and a photosensitizer adjuvant, even when a polarizing plate contains a film with low UV transmittance, the hardened layer which has desired performance can be formed.

It is preferable that a photosensitizer is a compound which shows maximum absorption to the light of wavelength longer than 380 nm, for example. As such a photosensitizer, the anthracene type compound etc. which were described below are mentioned.

9,10-dimethoxyanthracene,

9,10-diethoxyanthracene,

9,10-dipropoxyanthracene,

9,10-diisopropoxyanthracene,

9,10-dibutoxyanthracene,

9,10-dipentyloxyanthracene,

9,10-dihexyloxyanthracene,

9,10-bis(2-methoxyethoxy)anthracene,

9,10-bis(2-ethoxyethoxy)anthracene,

9,10-bis(2-butoxyethoxy)anthracene,

9,10-bis(3-butoxypropoxy)anthracene,

2-methyl- or 2-ethyl-9,10-dimethoxyanthracene,

2-methyl- or 2-ethyl-9,10-diethoxyanthracene,

2-methyl- or 2-ethyl-9,10-dipropoxyanthracene,

2-methyl- or 2-ethyl-9,10-diisopropoxyanthracene,

2-methyl- or 2-ethyl-9,10-dibutoxyanthracene,

2-methyl- or 2-ethyl-9,10-dipentyloxyanthracene,

2-methyl- or 2-ethyl-9,10-dihexyloxyanthracene.

A leveling agent is an additive which adjusts the fluidity|liquidity of a curable composition, and has the function of flattering the coating film obtained by apply|coating the composition, For example, silicone type, such as a silane coupling agent, polyacrylate type, and perfluoroalkyl type|system|group leveling agent. can be heard You may use a commercial item as a leveling agent.

To [ content of a leveling agent / 100 mass parts of polymeric compound ], Preferably they are 0.01 mass part or more and 5 mass parts or less, More preferably, they are 0.05 mass part or more and 3 mass parts or less.

When content of a leveling agent is in this range, there exists a tendency for a 2nd hardened|cured material layer to become smoother.

The thickness of the second cured product layer is preferably 0.1 µm or more and 10 µm or less, and more preferably 0.2 µm or more and 2 µm or less. When the thickness of a 2nd hardened|cured material layer is in this range, while being able to further exhibit the protective function with respect to the retardation layer, and the diffusion prevention function of a dichroic dye from a polarizer, thickness reduction of a polarizing plate becomes possible.

The second cured material layer is formed by coating an uncured composition for forming a second cured material layer on the surface of the first cured material layer 20 or the retardation layer 40 formed in contact with the polarizer 10, or 1 An uncured composition for forming a second cured material layer is dropped between the cured material layer 20 and the retardation layer 40, and the first cured material layer ( 20) formed by overlapping the polarizer 10 and the retardation layer 40, for example, by pressing from the top and bottom using a bonding roll or the like, after bonding, it can be formed by curing the composition for forming the second cured material layer. Hardening can be performed by irradiating an active energy ray and hardening (in the case of an active energy ray-curable composition), or heating and hardening (in the case of a thermosetting composition). An active energy ray may be irradiated from the polarizer 10 side, and may be irradiated from the retardation layer 40 side.

Various coating methods, such as a doctor blade, a wire bar, a die-coater, a comma coater, a gravure coater, can be used for coating of the composition for non-hardened 2nd hardened|cured material layer formation, for example. In addition, a method of casting an adhesive between the layers to be joined may be employed.

Any suitable conditions can be employ|adopted as the irradiation conditions of an active energy ray, as long as it is the conditions which can harden the said active energy ray-curable composition. For example, for electron beam irradiation, the acceleration voltage is preferably 5 kV to 300 kV, more preferably 10 kV to 250 kV. When the accelerating voltage is less than 5 kV, the electron beam does not reach the active energy ray-curable composition and there is a risk of insufficient curing. may cause damage to As an irradiation dose, it is 5-100 kGy, More preferably, it is 10-75 kGy. When the irradiation dose is less than 5 kGy, the active energy ray-curable composition lacks curing, and when it exceeds 100 kGy, the retardation layer is damaged, mechanical strength is lowered or yellowing occurs, and desired optical properties cannot be obtained.

The electron beam irradiation is usually carried out in an inert gas, but if necessary, it may be carried out in the atmosphere or under conditions in which oxygen is introduced slightly.

In the ultraviolet curable type, the light irradiation intensity with respect to the active energy ray curable composition is determined for each composition and is not particularly limited, but is preferably 10 to 1000 mJ/cm 2 . When the light irradiation intensity is less than 10 mJ/cm2, the reaction time becomes too long, and when it exceeds 1000 mJ/cm2, the possibility of yellowing of the constituent materials of the composition occurs due to heat radiated from the light source and heat generated during polymerization of the adhesive. have. Moreover, irradiation intensity becomes like this. Preferably it is intensity|strength in the wavelength range of wavelength 400 nm or less, More preferably, it is intensity|strength in the wavelength range of wavelength 280-320 nm. It is irradiated once or plural times with such light irradiation intensity, and the accumulated light amount is set to be preferably 10 mJ/cm 2 or more, more preferably 100 to 1000 mJ/cm 2 . When the amount of accumulated light with respect to the composition is less than 10 mJ/cm 2 , the generation of active species derived from the polymerization initiator is insufficient, and curing of the composition becomes insufficient. On the other hand, when the amount of accumulated light exceeds 1000 mJ/cm 2 , the irradiation time becomes very long, which is disadvantageous in improving productivity. At this time, the amount of accumulated light required in which wavelength region (UVA (320 to 390 nm) or UVB (280 to 320 nm), etc.) is different depending on the type of film to be used, the combination of the composition, and the like.

The light source used for polymerization and curing of the composition by irradiation with active energy rays in the present invention is not particularly limited, for example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, a xenon lamp, a halogen lamp, a carbon arc lamp, and a tungsten lamp, a gallium lamp, an excimer laser, an LED light source emitting a wavelength of 380 to 440 nm, a chemical lamp, a black light lamp, a microwave excited mercury lamp, and a metal halide lamp. It is preferable that it is an ultraviolet light source which has a light emission distribution at a wavelength of 400 nm or less from a viewpoint of energy stability and apparatus simplicity.

Also when using an active energy ray-curable composition, you may heat-process simultaneously with irradiation of an active energy ray or after irradiation of an active energy ray. Before forming the coating layer of the composition, an easily adhesive treatment such as saponification treatment, corona discharge treatment, plasma treatment, flame treatment, primer treatment or anchor coating treatment may be performed on one or both of the bonding surfaces.

The glass transition temperature of the second cured material layer is, for example, 0°C or higher, and may be 20°C or higher or 50°C or higher. The glass transition temperature of the second cured product layer is, for example, 150°C or less.

The glass transition temperature of the 2nd hardened|cured material layer is computable by the following procedure. A second cured material layer is formed between two stretched films of a cyclic polyolefin-based resin having a thickness of 25 μm. A container into which the sample for measurement is placed is set in a differential scanning calorimeter (DS, manufactured by TA Instruments), the temperature is lowered from 20°C to -60°C while purging nitrogen gas, and after reaching -60°C, hold for 1 minute , The temperature was increased from -60°C to 150°C at a temperature increase rate of 10°C/min, and when it reached 150°C, the temperature was immediately decreased to 20°C. Then, from the DSC curve when the temperature is raised from -60°C to 150°C, the midpoint glass transition temperature specified in JIS K 7121-1987 "Method for measuring transition temperature of plastics" is obtained, and this is the glass transition of the second cured material layer. was made with temperature.

The storage modulus of the second cured product layer at a temperature of 30° C. is preferably 100 MPa or more, more preferably 1000 MPa or more, more preferably 1500 MPa or more, particularly preferably from the viewpoint of improving the durability of the polarizing plate. more than 2000 MPa. On the other hand, when the storage elastic modulus of a 2nd hardened|cured material layer is too large, an adhesive agent hardened layer may become hard too much and the workability of a polarizing plate may fall. For this reason, the storage elastic modulus at the temperature of 30 degreeC of an adhesive agent hardened layer becomes like this. Preferably it is 10000 MPa or less, More preferably, it is 8000 MPa or less, More preferably, it is 5000 MPa or less.

The storage elastic modulus at the temperature of 80 degreeC of 2nd hardened|cured material layer is 10 MPa or more or 20 MPa or more, for example, and it is preferable that it is 100 MPa or more or 1000 MPa or more. It is preferable that it is 5000 MPa or less, as for the storage elastic modulus in the temperature of 80 degreeC of 2nd hardened|cured material layer, it is more preferable that it is 4000 MPa or less, It is still more preferable that it is 3500 MPa or less.

The storage elastic modulus of the second cured material layer can be calculated in the following procedure. A second cured material layer is formed between two 50 μm-thick cyclic polyolefin-based resin films. This is cut into the size of 5 mm x 30 mm, one cyclic polyolefin resin film is peeled, and the 2nd hardened|cured material layer with a resin film is obtained. This second cured material layer with a resin film was gripped at an interval of 2 cm between the handle mechanism using a dynamic viscoelasticity measuring device "DVA-220" manufactured by Haiti Metrology Control Co., Ltd. so that the long side of the second cured material layer was in the tensile direction, The temperature is raised by setting the frequency of contraction to 10 Hz and the temperature increase rate to 10°C/min, and the storage modulus at each temperature is determined.

<Manufacturing method of optical laminated body>

The manufacturing method of an optical laminated body is not specifically limited. In one embodiment, a step of applying and curing a polyvinyl alcohol-based resin composition on the surface of a polarizer to form a first cured material layer, and a first cured material layer and retardation layer formed on the surface of the polarizer are interposed with a cationically polymerizable composition and laminating, curing the cationically polymerizable composition to form a second cured product layer.

<Image display device>

An image display apparatus contains an image display panel and the said polarizing plate. In an image display apparatus, the said polarizing plate can be arrange|positioned and comprised on the front surface (viewing side) of an image display panel, for example. The image display panel is not particularly limited, and examples thereof include a liquid crystal display panel, an organic electroluminescent (organic EL) display panel, an inorganic electroluminescent (inorganic EL) display panel, a plasma display panel, and a field emission type display panel. have. An image display apparatus may be comprised by arrange|positioning a circularly polarizing plate on the visual recognition side of an organic electroluminescent display.

The image display device according to the present invention can be used as mobile devices such as smartphones and tablets, televisions, digital photo frames, electronic signs, measuring instruments and instruments, office equipment, medical equipment, computer equipment, and the like. The image display device according to the present invention is excellent in durability even when used in a harsh environment.

Example

Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited by these examples. In this Example, the polarizing plate was produced using the polarizer shown next, the 1st hardened|cured material layer, the 2nd hardened|cured material layer, and the retardation layer.

<Preparation of the laminate of Example 1>

[Production of polarizer with base film]

A film having a hard coat layer on one side of a 38 µm-thick polyethylene terephthalate (PET) production film was used as the base film. The hard-coat layer side surface of this base film was corona-treated, and the photo-alignment film was formed after that. A composition for forming a polarizer obtained by mixing a polymerizable liquid crystal compound, a dichroic azo dye, a polymerization initiator, a leveling agent and a solvent on the photo-alignment film was applied and dried, followed by UV irradiation to form a polarizer. Moreover, the surface protection film was bonded together on the base film side.

[Formation of the first cured product layer]

Corona-treated on the polarizer side surface of the produced polarizer with a base film. On the surface of the polarizer side after corona treatment, the polyvinyl alcohol-type resin composition was apply|coated by the bar-coating method (rate 30 mm/sec) so that the film thickness after hardening might be set to 1.0 micrometer. Conditions for corona treatment were 800 W output, 10 m/min processing speed, and 1 time. As a polyvinyl alcohol-type resin composition, the composition prepared by acetoacetyl-modified polyvinyl alcohol (trade name "Z-220", Mitsubishi Chemical Corporation) with pure water was used. Table 1 shows the details of Z-220. The coating layer of the polyvinyl alcohol-type resin composition was dried at 100 degreeC for 2 minutes, and the 1st polarizer with a hardened|cured material layer was obtained.

[Preparation of the phase difference layer]

As a retardation layer, the 1st protective film/orientation film/1/4 wave plate layer/adhesive layer/positive C layer/orientation film/an integral product in which the 2nd protective film was laminated|stacked was prepared. Each of the quarter wave plate layer and the positive C layer is a layer in which a composition containing a polymerizable liquid crystal compound is applied on an alignment film, dried, and cured by UV irradiation. The first protective film was a PET film with a thickness of 100 μm, and the second protective film was a PET film with a thickness of 38 μm.

[Joining of polarizer with 1st hardened|cured material layer and retardation layer]

The 1st hardened|cured material layer side surface of the polarizer with a 1st hardened|cured material layer, and the 1st protective film of the retardation layer were peeled, and the exposed surface was corona-treated. Conditions for corona treatment were 800 W output, 10 m/min processing speed, and 1 time. Both laminates were adhered using a laminator while applying an ultraviolet curable cationically polymerizable composition between the corona-treated first cured material layer surface and the retardation layer surface.

The thickness of the second cured product layer was 1.5 μm. Lamination conditions were a speed of 2.5 m/min. Ultraviolet rays were irradiated once with UVB 400 mj/cm 2 using an ultraviolet irradiation device. As the lamp, "H Bulb" manufactured by Fusion UV Systems Co., Ltd. was used. The environment at the time of ultraviolet irradiation was a temperature of 23 degreeC and a relative humidity of 55%RH. As described above, Example 1 in which a polarizer containing a dichroic azo dye, a first cured material layer, a second cured material layer, and a retardation layer containing a cured product of a polymerizable liquid crystal compound were laminated in contact with each other in this order of polarizing plate was obtained.

(Preparation of cationically polymerizable composition)

The cationically polymerizable composition was prepared by mixing each component shown in Table 2 below at a blending ratio (unit: parts by mass) shown in Table 2, followed by defoaming. In addition, the cationic polymerization initiator (B-1) was mix|blended as a 50% propylene carbonate solution, and Table 2 showed the solid content. The glass transition temperature and storage elastic modulus were measured according to the description of the above-mentioned [Second Cured Material Layer].

<Production of laminates of Examples 2-7>

A polarizing plate of Example 2 was produced in the same manner as in Example 1 except that the product name "Z-200" shown in Table 1 was used as the polyvinyl alcohol-based resin composition used for the first cured product layer. Polarizing plates of Examples 3 to 6 were produced in the same manner as in Example 2, except that glyoxal was further added to the polyvinyl alcohol-based resin composition in the amount shown in Table 3. The polarizing plate of Example 7 was produced by the method similar to Example 1 except having used the product name "PVA117" shown in Table 1 as a polyvinyl alcohol-type resin composition used for the 1st hardened|cured material layer.

The compounds in Table 2 are as follows.

(cationically polymerizable compound (A))

A-1: 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (trade name: CEL2021P, manufactured by Daicel Co., Ltd.)

A-2: 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol (trade name: EHPE3150, manufactured by Daicel Corporation)

A-3: 3-ethyl-3 {[(3-ethyloxetan-3-yl) methoxy] methyl} oxetane (trade name: OXT-221, manufactured by Toagosei Co., Ltd.)

(Cation polymerization initiator (B))

B-1: "CPI-100 P", manufactured by San Apro Co., Ltd., 50% by mass solution

(Photosensitizer (C))

C-1: 1,4-diethoxynaphthalene

<Production of the laminate of Comparative Example 1>

As the comparative example 1, the laminated body which did not have a 1st hardened|cured material layer and a 2nd hardened|cured material layer, and the polarizer and retardation layer were bonded through the adhesive layer was prepared in the following procedure.

First, a pressure-sensitive adhesive sheet in which an acrylic pressure-sensitive adhesive layer having a thickness of 5 µm was formed between the light-peelable film and the medium-peelable film as the pressure-sensitive adhesive layer was prepared. The polarizer side of the polarizer with a base film of Example 1, and the exposed surface after peeling the light-peelable film of an adhesive sheet were bonded together. Before bonding, the surface of the polarizer was corona-treated three times at an output of 800 W and a processing rate of 10 m/min once, and the pressure-sensitive adhesive layer surface at an output of 280 W and a processing rate of 10 m/min. The exposed surface after peeling the 1st protective film of the retardation layer of Example 1, and the exposed surface after peeling the heavy peeling sheet of an adhesive sheet were bonded together. Before bonding, the phase difference layer surface was corona-treated once at an output of 800 W and a processing speed of 10 m/min, and the pressure-sensitive adhesive layer surface was corona-treated three times at an output of 280 W and a processing speed of 10 m/min. Thereby, the laminate of Comparative Example 1 was obtained. Methods other than those specifically described were the same as in Example 1.

<Production of the laminate of Comparative Example 2>

As a comparative example 2, the laminated body by which the polarizer with a 1st hardened|cured material layer and retardation layer were bonded through the adhesive layer was prepared without having a 2nd hardened|cured material layer. The laminate of the comparative example 2 was obtained by the method similar to the manufacturing method of the laminated body of the comparative example 1 except having used the polarizer with a 1st hardened|cured material layer of Example 2 as a polarizer. That is, a pressure-sensitive adhesive layer is laminated on the first cured material layer side of the polarizer with a first cured material layer described in Example 1, and 1/4 wavelength of the retardation layer described in Example 1 on the opposite side to the first cured material layer of the pressure-sensitive adhesive layer The plate layer side was further laminated|stacked.

<Production of the laminate of Comparative Example 3>

As a comparative example 3, the laminated body by which the polarizer with a 1st hardened|cured material layer, and retardation layer were bonded together via the 2nd hardened|cured material layer and an adhesive layer was obtained. First, the polarizer with a 1st hardened|cured material layer of Example 2 was prepared.

Corona treatment is performed on the first cured material layer side of the polarizer with the first cured material layer, and the cationically polymerizable composition is applied between the corona treated surface and the cycloolefin film that is not corona treated, and both laminates are adhered using a laminator. did it After curing the composition by irradiation with ultraviolet rays to form a second cured product layer, the cycloolefin film was peeled off. Next, the exposed surface after peeling the 2nd hardened|cured material layer side of a polarizer, and the light-peelable film of the adhesive sheet of the comparative example 1 was bonded together. Moreover, the exposed surface after peeling the 1st protective film of the retardation layer of Example 1, and the exposed surface after peeling the heavy peeling sheet of an adhesive sheet were bonded together. As described above, a laminate of Comparative Example 3 was obtained. Methods other than those described were the same as in Example 1 or Comparative Example 1.

<Evaluation of durability of polarizer and retardation layer>

The 2nd protective film was peeled from the laminated body of an Example and a comparative example, and it bonded with the acrylic adhesive sheet (with a peeling film) 15 micrometers in thickness. This laminate was cut to a size of 30 mm × 30 mm, and an acrylic pressure-sensitive adhesive layer exposed by peeling a release film was applied to an alkali-free glass manufactured by Corning Corporation (trade name: Eagle XG, 40 mm × 40 mm × thickness 0.7 mm). to prepare a sample subjected to autoclave treatment at a temperature of 50°C.

[Measurement of polarization degree]

Each sample was left to stand in the oven set to high temperature (temperature 85 degreeC dry) conditions for 168 hours. The visibility corrected polarization degree (Py1) (%) before putting in the oven and the visibility corrected polarization degree (Py2) (%) left in the oven for 168 hours were measured with a spectrophotometer (V-7100 manufactured by Nippon Bunko), and the amount of change ΔPy was calculated based on the following formula.

ΔPy=|Py2-Py1|

ΔPy was evaluated based on the following criteria.

A: The amount of change ΔPy of the degree of polarization is less than 0.5

B: The amount of change ΔPy of the degree of polarization is 0.5 or more and less than 1.0

C: The amount of change ΔPy of the degree of polarization is 1.0 or more

[Measurement of phase difference]

A test sample was prepared in the same manner as above. Each sample was left to stand for 168 hours in the oven set to high-temperature, high-humidity conditions (temperature 65 degreeC, relative humidity 90%RH). The in-plane retardation value (Re1) (nm) at a wavelength of 550 nm before being put into the oven and the in-plane retardation value (Re2) (nm) at a wavelength of 550 nm after being left in the oven for 168 hours were measured using a phase difference measuring apparatus KOBRA-WPR (Oh (manufactured by Paper Measuring Instruments Co., Ltd.), and ΔRe, which is the amount of change, was calculated based on the following formula.

ΔRe=|Re2-Re1|

ΔRe was evaluated based on the following criteria.

A: The amount of change ΔRe of the phase difference value is less than 0.5

B: The amount of change ΔRe of the phase difference value is 0.5 or more and less than 2.5

C: The amount of change ΔRe of the phase difference value is 2.5 or more

[Hot water immersion test]

A sample in which a polarizing plate was laminated on alkali-free glass was prepared in the same manner as above. The sample was cut into strips in a size of 50 mm x 20 mm with the absorption axis of the polarizer as the long side, and the dimension in the long side direction was accurately measured. One short side of this sample was gripped by a gripping mechanism, and about 80% of the longitudinal direction was immersed in a water bath at 60°C and held for 3 minutes. After that, the sample was taken out of the water bath and the moisture was wiped off. The polarizer of the polarizing plate contracts by immersion in warm water. The distance from the edge of the sample (end of glass) to the edge of the polarizer which contracted|contracted in the center of the sample short side was measured for the shrinkage|contraction degree of this polarizer. The obtained measured values were evaluated on the basis of the following criteria.

A: The distance from the end of the sample to the end of the polarizer is 3 mm or less

B: the distance from the end of the sample to the end of the polarizer is greater than 3 mm

The polarizer, the first cured material layer, the second cured material layer, and the retardation layer are laminated in contact with each other in this order, the first cured material layer is a cured material layer of the polyvinyl alcohol-based resin composition, and the second cured material layer is cationic polymerization As for the polarizing plate which is a hardened|cured material layer of a sexual composition, ΔPy in a temperature of 85 degreeC is small, and it is thought that the pigment|dye diffusion of the polarizer under high temperature was suppressed. Moreover, such a polarizing plate has small ΔRe at a temperature of 65°C and a relative humidity of 90% RH, and it is considered that the diffusion of monomers in the retardation layer under high temperature and high humidity is suppressed. In addition, when the polyvinyl alcohol-based resin composition contains acetoacetyl-modified polyvinyl alcohol, it can be seen that water resistance is also improved.

100: polarizing plate, 10: polarizer, 20: first cured material layer, 30: second cured material layer, 40: retardation layer.

Claims (11)

A polarizer containing a dichroic azo dye, a first cured material layer, a second cured material layer, and a retardation layer including a cured product of a polymerizable liquid crystal compound are laminated in contact with each other in this order,
The first cured material layer is a cured material layer of the polyvinyl alcohol-based resin composition,
The second cured material layer is a polarizing plate that is a cured material layer of the cationically polymerizable composition. The polarizing plate of claim 1, wherein the polyvinyl alcohol-based resin composition comprises acetoacetyl group-modified polyvinyl alcohol. The polarizing plate according to claim 1 or 2, wherein a degree of saponification of the polyvinyl alcohol-based resin included in the polyvinyl alcohol-based resin composition is 85 mol% or more and 100 mol% or less. The polarizing plate according to any one of claims 1 to 3, wherein the degree of polymerization of the polyvinyl alcohol-based resin included in the polyvinyl alcohol-based resin composition is 1000 or more and 5000 or less. The polyvinyl alcohol-based resin composition according to any one of claims 1 to 4, wherein the polyvinyl alcohol-based resin composition does not contain an aldehyde compound or contains 8.0 parts by mass or less of an aldehyde compound based on 100 parts by mass of the polyvinyl alcohol-based resin. polarizer. The polarizing plate according to any one of claims 1 to 5, wherein the cationically polymerizable composition comprises an oxetane compound. The polarizing plate according to claim 6, wherein the cationically polymerizable composition further comprises an epoxy compound. The polarizing plate according to claim 7, wherein the cationically polymerizable composition contains 10 parts by mass or more and 2000 parts by mass or less of the oxetane compound with respect to 100 parts by mass of the epoxy compound. The polarizing plate according to any one of claims 1 to 8, wherein the cationically polymerizable composition further comprises a photosensitizer. The polarizing plate according to any one of claims 1 to 9, wherein the retardation layer comprises a quarter wave plate layer. The image display apparatus containing the polarizing plate in any one of Claims 1-10.

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