JP2013210512A - Polarizing element, optical film, and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarizing element with a liquid crystal layer, in which the liquid crystal layer where alignment of a liquid crystalline compound is fixed is laminated on at least one surface of a polarizer via an adhesive layer and adhesion between the liquid crystal layer and the polarizer is good.SOLUTION: In the polarizing element, a liquid crystal layer where alignment of a liquid crystalline compound is fixed is laminated on at least one surface of a polarizer via an adhesive layer and a hydrophilic layer in this order from the side of the polarizer.

Description

  The present invention relates to a polarizing element having a liquid crystal layer on at least one surface of a polarizer. The polarizing element can form an image display device such as a liquid crystal display device (LCD), an organic EL display device, a CRT, or a PDP alone or as an optical film in which the polarizing element is laminated.

  An optical film having birefringence is used as a member for realizing an improvement in contrast and an increase in viewing angle in an image display device such as a liquid crystal display device. As an example of such an optical film, a liquid crystal layer in which the orientation of a liquid crystal compound is fixed is formed on a substrate. Since the liquid crystalline compound has orientation, for example, when applied to the surface of a substrate such as a stretched film or an oriented film, the molecules are oriented according to the orientation regulating force, and the coated film exhibits birefringence characteristics (patent Reference 1).

  The liquid crystal layer in which the orientation of the liquid crystal compound is fixed has a large birefringence, and an equivalent retardation can be obtained with a small thickness compared to a stretched film of a polymer film. It has been attracting attention with the trend of climatization. Moreover, the liquid crystalline compound can form a liquid crystal layer having a different alignment state for each minute region by fixing the alignment of the liquid crystalline compound using a mask pattern or the like. The polarizing element having such a liquid crystal layer can be applied to, for example, a space-division type three-dimensional display that displays a right-eye image and a left-eye image for each pixel.

  Such a liquid crystal layer is generally formed on a substrate such as a transparent protective film, and then bonded or transferred onto an optical member such as a polarizing plate, so that a liquid crystal display device as a polarizing element with a liquid crystal layer is used. Etc. Such a polarizing element with a liquid crystal layer has, for example, a laminated structure as shown in FIG. In the polarizing element with a liquid crystal layer in FIG. 3, the liquid crystal is applied on one transparent protective film T of the polarizing plate in which the transparent protective films T and T ′ are bonded to both surfaces of the polarizer P via adhesive layers A and A ′, respectively. Layer C is formed. As a polarizing element with a liquid crystal layer, there is an element having a laminated structure other than the form shown in FIG. 3, but generally, as shown in FIG. 3, a transparent protective film is attached to the polarizer via an adhesive layer. A liquid crystal layer is formed thereon.

  On the other hand, for a polarizing element having a birefringent layer other than the liquid crystal layer, from the viewpoint of thinning the polarizing element, the polarizer and the amorphous polymer layer as the birefringent layer are bonded without using a transparent protective film. Has been proposed (Patent Document 2).

Japanese Patent No. 2631015 JP 2003-344657 A

  Similarly to Patent Document 2, in the polarizing element with a liquid crystal layer, as shown in FIG. 4, if the polarizer P and the liquid crystal layer C are bonded via the adhesive layer A without using the transparent protective film, This can contribute to reduction in thickness and cost of the polarizing element. However, the adhesion at the interface between the liquid crystal layer and the adhesive layer is not sufficient and the polarizing element with the liquid crystal layer in which the liquid crystal layer and the polarizer are directly bonded via the adhesive layer, and used under high temperature and high humidity. In some cases, peeling may occur between the liquid crystal layer and the polarizer. Moreover, in the polarizing element with a liquid crystal layer shown in FIG. 4, when the polarizing element containing a defect is peeled from the glass substrate of the liquid crystal cell, peeling tends to occur between the liquid crystal layer and the polarizer, and reworkability tends to be poor. is there.

  The present invention is a polarizing element with a liquid crystal layer in which a liquid crystal layer in which the orientation of a liquid crystalline compound is fixed via an adhesive layer is provided on at least one surface of a polarizer, the liquid crystal layer, the polarizer, An object of the present invention is to provide a polarizing element with a liquid crystal layer having good adhesion between the two.

  Another object of the present invention is to provide an optical film having the polarizing element with a liquid crystal layer, and further to provide an image display device using the polarizing element with a liquid crystal layer or the optical film.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found the following polarizing elements and completed the present invention.

  That is, in the present invention, a liquid crystal layer in which the orientation of the liquid crystal compound is fixed is provided on at least one surface of the polarizer through the adhesive layer and the hydrophilic layer in this order from the polarizer side. The polarizing element characterized by this.

  In the polarizing element, it is preferable that the hydrophilic layer is formed from an organic silicon compound or a urethane resin.

  In the polarizing element, the organosilicon compound preferably has a double bond. Moreover, as a double bond which the said organosilicon compound has, a (meth) acryloyl group is preferable.

  In the polarizing element, it is preferable that the adhesive layer is formed of a cured product layer obtained by irradiating an active energy ray-curable adhesive with active energy. The active energy ray-curable adhesive preferably contains a radical polymerizable compound. The radical polymerizable compound preferably contains an N-substituted amide monomer.

  In the polarizing element, the liquid crystal layer preferably has a front phase difference of 90 to 190 nm.

  In the polarizing element, the liquid crystal layer may have a front phase difference, and a plurality of regions each having a slow axis in a different direction may be used in a predetermined pattern.

  In the polarizing element, the liquid crystal layer may have a transparent protective film on the side opposite to the side where the hydrophilic layer is provided.

  The present invention also relates to an optical film in which at least one polarizing element is laminated.

  The present invention also relates to an image display device using the polarizing element or the optical film.

  In the polarizing element of the present invention, the polarizer is provided with a liquid crystal layer in which the orientation of the liquid crystalline compound is fixed via an adhesive layer. The adhesive layer and the liquid crystal layer are interposed via a hydrophilic layer. Is provided. The presence of the hydrophilic layer improves the adhesion between the liquid crystal layer and the polarizer. As a result, the polarizing element of the present invention can suppress peeling between the liquid crystal layer and the polarizer even when the polarizing element is provided under a high temperature and high humidity condition. Reworkability is also good.

It is sectional drawing which shows an example of the polarizing element of this invention. It is sectional drawing which shows an example of the polarizing element of this invention. It is sectional drawing of the conventional polarizing element. It is sectional drawing of the polarizing element shown for reference.

  The polarizing element of the present invention will be described below with reference to the drawings. In FIG. 1, a first adhesive layer A, a hydrophilic layer B, and a liquid crystal layer C are provided in this order on one surface of the polarizer P from the polarizer P side, and a transparent protective film T is further provided. It is the case. In FIG. 1, the transparent protective film T is directly provided on the liquid crystal layer C. However, in order to improve the adhesion between the liquid crystal layer C and the transparent protective film T, the liquid crystal layer C and the transparent protective film T are provided. A modified layer can be provided between the two. The modified layer can be formed of the same material as the hydrophilic layer B. FIG. 2 shows a case where the transparent protective film T is not provided in FIG. The other surface of the polarizer 1 is not particularly limited, and no layer may be provided on the polarizer 1. 1 and 2 exemplify a case where a transparent protective film T ′ is bonded to the other surface of the polarizer 1 via a second adhesive layer A ′. On the other surface of P, the liquid crystal layer C can also be provided with or without the hydrophilic layer B interposed therebetween.

<Polarizer>
The polarizer is not particularly limited, and various types can be used. Examples of polarizers include dichroic iodine and dichroic dyes on hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films. Examples thereof include polyene-based oriented films such as those obtained by adsorbing substances and uniaxially stretched, polyvinyl alcohol dehydrated products and polyvinyl chloride dehydrochlorinated products. Among these, a polarizer composed of a polyvinyl alcohol film and a dichroic material such as iodine is preferable. The thickness of these polarizers is not particularly limited, but is generally about 1 to 80 μm.

  A polarizer obtained by dyeing a polyvinyl alcohol film with iodine and uniaxially stretching it can be prepared, for example, by immersing polyvinyl alcohol in an aqueous solution of iodine and stretching it 3 to 7 times the original length. If necessary, it can be immersed in an aqueous solution such as potassium iodide which may contain boric acid, zinc sulfate, zinc chloride or the like. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing. In addition to washing the polyvinyl alcohol film surface with dirt and anti-blocking agents by washing the polyvinyl alcohol film with water, it also has the effect of preventing unevenness such as uneven coloring by swelling the polyvinyl alcohol film. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching. The film can be stretched even in an aqueous solution such as boric acid or potassium iodide or in a water bath.

<Adhesive layer>
The adhesive for forming the adhesive layer is not particularly limited as long as it is optically transparent, and water-based, solvent-based, hot melt-based, and active energy ray-curable types are used. The thickness of the adhesive layer is designed according to the type of the adhesive, but it is usually preferable to adjust in the range of 0.05 to 10 μm. In the present invention, an active energy ray curable adhesive is suitable from the viewpoint of productivity. Hereinafter, the active energy ray-curable adhesive will be described.

<Active energy ray-curable adhesive>
The active energy ray curable adhesive is an adhesive that cures by an active energy ray such as an electron beam or ultraviolet ray, and can be used in an electron beam curable type or an ultraviolet ray curable type, for example. In the present invention, an ultraviolet curable adhesive is preferable from the viewpoint of durability.

  The active energy ray-curable adhesive used in the present invention can be either a photocationic polymerization type or a photoradical polymerization type, but the active energy ray-curable adhesive of the present invention is a photoradical polymerization type. An adhesive is preferable in terms of durability.

  When the photo radical polymerization type active energy ray curable adhesive is used as the ultraviolet curable type, the adhesive contains (A) a radical polymerizable compound and (B) a photo radical generator.

≪ (A) Radical polymerizable compound≫
The (A) radical polymerizable compound can be used without particular limitation as long as it is a compound having a vinyl group containing at least one carbon-carbon double bond, a (meth) acryloyl group, and the like. (A) The radically polymerizable compound may be monofunctional or bifunctional or higher. Moreover, (A) radically polymerizable compound can select 1 type, or can be used in combination of 2 or more type. As these (A) radically polymerizable compounds, compounds having a (meth) acryloyl group are suitable. As the compound having a (meth) acryloyl group, an N-substituted amide monomer is preferably used. These monomers are preferable in terms of adhesiveness. The (meth) acryloyl group means an acryloyl group and / or a methacryloyl group. In the present invention, (meta) has the same meaning as described above.

(A) As a radically polymerizable compound, an N-substituted amide monomer is preferable. The N-substituted amide monomer has the general formula (1): CH ₂ = C (R ¹ ) —CONR ² (R ³ ) (R ¹ represents a hydrogen atom or a methyl group, R ² represents a hydrogen atom or a hydroxyl group, mercapto Represents a linear or branched alkyl group having 1 to 4 carbon atoms which may have a group, an amino group or a quaternary ammonium group, and R ³ represents a hydrogen atom or a linear or branched chain having 1 to 4 carbon atoms Wherein R ² and R ³ are simultaneously a hydrogen atom, or R ² and R ³ are bonded to form a 5-membered ring or a 6-membered ring that may contain an oxygen atom. It is expressed by Examples of the linear or branched alkyl group having 1 to 4 carbon atoms for R ² or R ³ in the general formula (1) include a methyl group, an ethyl group, an isopropyl group, and a t-butyl group. Examples of the alkyl group having a hydroxyl group include a hydroxymethyl group and a hydroxyethyl group, and examples of the alkyl group having an amino group include an aminomethyl group and an aminoethyl group. Moreover, when R < ² >, R < ³ > couple | bonds together and forms the 5-membered ring or 6-membered ring which may contain an oxygen atom, it has a heterocyclic ring which has nitrogen. Examples of the heterocyclic ring include morpholine ring, piperidine ring, pyrrolidine ring, piperazine ring and the like.

  Specific examples of the N-substituted amide monomer include, for example, N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropylacrylamide, N- Butyl (meth) acrylamide, N-hexyl (meth) acrylamide, N-methylol (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N-methylol-N-propane (meth) acrylamide, aminomethyl (meth) acrylamide, Examples include aminoethyl (meth) acrylamide, mercaptomethyl (meth) acrylamide, and mercaptoethyl (meth) acrylamide. Examples of the heterocycle-containing monomer having a heterocycle include N-acryloylmorpholine, N-acryloylpiperidine, N-methacryloylpiperidine, N-acryloylpyrrolidine and the like.

  As the N-substituted amide monomer represented by the general formula (1), commercially available products can also be suitably used. Specifically, for example, N-hydroxyethyl acrylamide (trade name “HEAA”, manufactured by Kojin Co., Ltd.), N-methoxymethyl acrylamide (trade name “NMMA”, manufactured by MRC Unitech Co., Ltd.), N-butoxymethyl acrylamide (trade name) “NBMA” (manufactured by MRC Unitech), N-methoxymethylmethacrylamide (trade name “Wassmer 2MA”, manufactured by Kasano Kosan Co., Ltd.), and the like.

  As the N-substituted amide monomer represented by the general formula (1), a hydroxyl group-containing N-substituted amide monomer is suitable, and examples thereof include N-hydroxyethyl (meth) acrylamide. The N-substituted amide-based monomer exhibits good adhesion to a transparent protective film using a low moisture content polarizer or a material with low moisture permeability. Among the monomers exemplified above, N- Hydroxyethyl acrylamide exhibits particularly good adhesion.

  The active energy ray-curable adhesive (A) is a monofunctional compound having an N-substituted amide monomer other than that represented by the general formula (1), various aromatic rings and a hydroxy group as a radical polymerizable compound. You may contain the compound etc. which have (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate, various (meth) acryloyl groups. However, when the adhesiveness and water resistance of the adhesive layer are taken into consideration, the ratio of the N-substituted amide monomer represented by the general formula (1) to the total amount of the (A) radical polymerizable compound is 50 to 99. It is preferable that it is weight%, and it is more preferable that it is 60 to 90 weight%.

  As the monofunctional (meth) acrylate having an aromatic ring and a hydroxy group, various monofunctional (meth) acrylates having an aromatic ring and a hydroxy group can be used. The hydroxy group may exist as a substituent of the aromatic ring, but in the present invention, it exists as an organic group (bonded to a hydrocarbon group, particularly an alkylene group) that bonds the aromatic ring and the (meth) acrylate. Those that do are preferred.

  Examples of the monofunctional (meth) acrylate having an aromatic ring and a hydroxy group include a reaction product of a monofunctional epoxy compound having an aromatic ring and (meth) acrylic acid. Examples of the monofunctional epoxy compound having an aromatic ring include phenyl glycidyl ether, t-butylphenyl glycidyl ether, and phenyl polyethylene glycol glycidyl ether. Specific examples of the monofunctional (meth) acrylate having an aromatic ring and a hydroxy group include, for example, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2-hydroxy-3-t-butylphenoxypropyl (meth) Acrylate, 2-hydroxy-3-phenyl polyethylene glycol propyl (meth) acrylate, etc. are mentioned.

  Moreover, as said urethane (meth) acrylate, the hydroxyl group of the one end of diol compounds, such as (meth) acrylate which has an isocyanate group, and polyalkylene glycols, such as polyurethane diol, polyester diol, polyether diol, polyethylene glycol, polypropylene glycol, etc. And a reaction product thereof.

  As a compound having a (meth) acryloyl group, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate C 1-12 alkyl (meth) acrylates such as lauryl (meth) acrylate; (meth) acrylic acid alkoxyalkyl monomers such as (meth) acrylic acid methoxyethyl and (meth) acrylic acid ethoxyethyl; ) 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, (meta Acrylic acid Hydroxyl group-containing monomers such as 0-hydroxydecyl, 12-hydroxylauryl (meth) acrylate and (4-hydroxymethylcyclohexyl) -methyl acrylate; Acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; acrylic acid Caprolactone adducts: styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid And sulfonic acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate and the like. (Meth) acrylamide; maleimide, N-cyclohexylmaleimide, N-phenylmaleimide, etc .; aminoethyl (meth) acrylate, aminopropyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate , (Meth) acrylic acid alkylaminoalkyl monomers such as (meth) acrylic acid t-butylaminoethyl, 3- (3-pyridinyl) propyl (meth) acrylate; N- (meth) acryloyloxymethylene succinimide and N- ( And nitrogen-containing monomers such as succinimide monomers such as (meth) acryloyl-6-oxyhexamethylene succinimide and N- (meth) acryloyl-8-oxyoctamethylene succinimide.

  The active energy ray-curable adhesive further comprises (A) a radical polymerizable compound, (C) a monomer having two or more carbon-carbon double bonds, particularly preferably a polyfunctional (meth) acrylate monomer. When it contains, since the water resistance of an adhesive bond layer improves, it is preferable. In consideration of the water resistance of the adhesive layer, the monomer having two or more carbon-carbon double bonds is more preferably hydrophobic. Monomers having two or more hydrophobic carbon-carbon double bonds, particularly hydrophobic polyfunctional (meth) acrylate monomers include, for example, tricyclodecane dimethanol diacrylate, divinylbenzene, N, N′-methylene. Bisacrylamide, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) Acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol glycol di (meth) acrylate, glycerin di (meth) acrylate, EO modified glycerin tri (meth) acrylate, EO modified diglycerin tetra ( (Meth) acrylate, (meth) acrylic acid 2- (2-vinyloxyethoxy) ethyl, bisphenol A-EO adduct di (meth) acrylate, trimethylolpropane tri (meth) acrylate, hydroxypivalate neopentyl glycol (meth) Acrylic acid adduct, EO-modified trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, iso Anuric acid EO-modified di (meth) acrylate, isocyanuric acid EO-modified tri (meth) acrylate, ε-caprolactone-modified tris ((meth) acryloxyethyl) isocyanurate, 1,1-bis ((meth) acryloyloxymethyl) ethyl Examples include isocyanate, a polymer of 2-hydroxyethyl (meth) acrylate and 1,6-diisocyanate hexane, 9,9-bis [4- (2- (meth) acryloyloxyethoxy) phenyl] fluorene, and the like.

  (A) The ratio of the monomer having two or more carbon-carbon double bonds to the total amount of the radical polymerizable compound is preferably 5 to 50% by weight, and more preferably 9 to 40% by weight. . When this ratio is less than 5% by weight, sufficient water resistance may not be obtained. On the other hand, when it exceeds 50% by weight, sufficient adhesion may not be obtained.

<< (B) Photoradical generator >>
(B) The photo radical generator generates radicals by irradiating active energy rays. (B) Examples of the photo radical generator include a hydrogen abstraction type photo radical generator and a cleavage type photo radical generator.

  Examples of the hydrogen abstraction type photo radical generator include 1-methylnaphthalene, 2-methylnaphthalene, 1-fluoronaphthalene, 1-chloronaphthalene, 2-chloronaphthalene, 1-bromonaphthalene, 2-bromonaphthalene, 1-iodonaphthalene. , 2-iodonaphthalene, 1-naphthol, 2-naphthol, 1-methoxynaphthalene, 2-methoxynaphthalene, naphthalene derivatives such as 1,4-dicyanonaphthalene, anthracene, 1,2-benzanthracene, 9,10-dichloroanthracene , 9,10-dibromoanthracene, 9,10-diphenylanthracene, 9-cyanoanthracene, 9,10-dicyanoanthracene, 2,6,9,10-tetracyanoanthracene, anthracene derivatives, pyrene derivatives, carbazole 9-methylcarbazole, 9-phenylcarbazole, 9-prop-2-ynyl-9H-carbazole, 9-propyl-9H-carbazole, 9-vinylcarbazole, 9H-carbazole-9-ethanol, 9-methyl-3-nitro -9H-carbazole, 9-methyl-3,6-dinitro-9H-carbazole, 9-octanoylcarbazole, 9-carbazolemethanol, 9-carbazolepropionic acid, 9-carbazolepropionitrile, 9-ethyl-3,6 -Dinitro-9H-carbazole, 9-ethyl-3-nitrocarbazole, 9-ethylcarbazole, 9-isopropylcarbazole, 9- (ethoxycarbonylmethyl) carbazole, 9- (morpholinomethyl) carbazole, 9-acetylcarbazole, 9- Allyl Rubazole, 9-benzyl-9H-carbazole, 9-carbazoleacetic acid, 9- (2-nitrophenyl) carbazole, 9- (4-methoxyphenyl) carbazole, 9- (1-ethoxy-2-methyl-propyl) -9H -Carbazole, 3-nitrocarbazole, 4-hydroxycarbazole, 3,6-dinitro-9H-carbazole, 3,6-diphenyl-9H-carbazole, 2-hydroxycarbazole, 3,6-diacetyl-9-ethylcarbazole, etc. Carbazole derivatives, benzophenone, 4-phenylbenzophenone, 4,4'-bis (dimethoxy) benzophenone, 4,4'-bis (dimethylamino) benzophenone, 4,4'-bis (diethylamino) benzophenone, methyl 2-benzoylbenzoate Ester, 2- Benzophenone derivatives such as methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 3,3′-dimethyl-4-methoxybenzophenone, 2,4,6-trimethylbenzophenone, aromatic carbonyl compounds, [4- (4-methyl Phenylthio) phenyl] -phenylmethanone, xanthone, thioxanthone, 2-chlorothioxanthone, 4-chlorothioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 1- Examples include thioxanthone derivatives such as chloro-4-propoxythioxanthone and coumarin derivatives.

  The cleavage type photo radical generator is a type of photo radical generator that generates radicals by cleavage of the compound upon irradiation with active energy rays. Specific examples thereof include arylalkyls such as benzoin ether derivatives and acetophenone derivatives. Examples include, but are not limited to, ketones, oxime ketones, acylphosphine oxides, S-phenyl thiobenzoates, titanocenes, and derivatives obtained by increasing the molecular weight thereof. Commercially available cleavage type photo radical generators include 1- (4-dodecylbenzoyl) -1-hydroxy-1-methylethane, 1- (4-isopropylbenzoyl) -1-hydroxy-1-methylethane, 1-benzoyl. -1-hydroxy-1-methylethane, 1- [4- (2-hydroxyethoxy) -benzoyl] -1-hydroxy-1-methylethane, 1- [4- (acryloyloxyethoxy) -benzoyl] -1-hydroxy- 1-methylethane, diphenyl ketone, phenyl-1-hydroxy-cyclohexyl ketone, benzyldimethyl ketal, bis (cyclopentadienyl) -bis (2,6-difluoro-3-pyryl-phenyl) titanium, (η6-isopropylbenzene) -(Η5-cyclopentadienyl) -iron (II) hexaf Fluorophosphate, trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxy-benzoyl)-(2,4,4-trimethyl-pentyl) -phosphine oxide, bis (2,4,6-trimethylbenzoyl) -2, 4-dipentoxyphenylphosphine oxide or bis (2,4,6-trimethylbenzoyl) phenyl-phosphine oxide, (4-morpholinobenzoyl) -1-benzyl-1-dimethylaminopropane, 4- (methylthiobenzoyl) -1 -Methyl-1-morpholinoethane may be mentioned, but is not limited thereto.

  (B) The photoradical generator, that is, the hydrogen abstraction type or cleavage type photoradical generator can be used alone or in combination, but the stability of the photoradical generator alone is also possible. In addition, the combination of one or more cleavage type photoradical generators is more preferable in terms of curability of the composition in the present invention. Among the cleavage type photo radical generators, acylphosphine oxides are preferable. More specifically, trimethylbenzoyldiphenylphosphine oxide (trade name “DAROCURE TPO”; manufactured by Ciba Japan), bis (2,6-dimethoxy-benzoyl) )-(2,4,4-trimethyl-pentyl) -phosphine oxide (trade name “CGI 403”; manufactured by Ciba Japan) or bis (2,4,6-trimethylbenzoyl) -2,4-dipen Toxiphenylphosphine oxide (trade name “IRGACURE819”; manufactured by Ciba Japan Co., Ltd.) is preferable.

  (B) The content of the photo radical generator is preferably 0.01 to 10 parts by weight, and preferably 0.05 to 5 parts by weight with respect to the total amount of the active energy ray-curable adhesive. More preferred is 0.1 to 3 parts by weight.

  In addition, when the active energy ray-curable adhesive according to the present invention is used in an electron beam curing type, the above-mentioned (B) photoradical generator can be arbitrarily used as the adhesive. Moreover, you may add the sensitizer which raises the cure rate and sensitivity by an electron beam represented by the carbonyl compound.

  Examples of the sensitizer include anthracene, phenothiazene, perylene, thioxanthone, and benzophenone thioxanthone. Further, sensitizing dyes include thiopyrylium salt dyes, merocyanine dyes, quinoline dyes, styrylquinoline dyes, ketocoumarin dyes, thioxanthene dyes, xanthene dyes, oxonol dyes, cyanine dyes, rhodamine dyes. And pyrylium salt pigments.

  As specific anthracene compounds, dibutoxyanthracene, dipropoxyanthraquinone (Anthracure UVS-1331, 1221 manufactured by Kawasaki Kasei Co., Ltd.) and the like are effective.

  When adding a sensitizer, the content is preferably 0.01 to 20 parts by weight, more preferably 0.01 to 10 parts by weight, based on the total amount of the active energy ray-curable adhesive. The amount is preferably 0.1 to 3 parts by weight.

  Moreover, various additives can be mix | blended with the said active energy ray hardening-type adhesive agent as another arbitrary component in the range which does not impair the objective and effect of this invention. Such additives include polyamide, polyamideimide, polyurethane, polybutadiene, polychloroprene, polyether, polyester, styrene-butadiene block copolymer, petroleum resin, xylene resin, ketone resin, cellulose resin, fluorine-based oligomer, silicone-based oligomer. Polymers such as polysulfide oligomers or oligomers; Polymerization inhibitors such as phenothiazine and 2,6-di-t-butyl-4-methylphenol; polymerization initiators; leveling agents; wettability improvers; UV absorbers; silane coupling agents; inorganic fillers; pigments; dyes and the like. However, in the active energy ray-curable adhesive, the content of the above-described additive is preferably 0.005 to 20 parts by weight with respect to the total amount of the active energy ray-curable adhesive, and 0.01 to 10 weights. More preferably, it is 0.1 to 5 parts by weight.

  In addition, as a photocationic polymerization type active energy ray-curable adhesive, for example, a composition containing a compound having an epoxy group and a photoacid generator can be used.

  The coating method of the active energy ray-curable adhesive is appropriately selected depending on the viscosity of the composition and the target thickness. Examples of coating methods include reverse coaters, gravure coaters (direct, reverse and offset), bar reverse coaters, roll coaters, die coaters, bar coaters, rod coaters and the like. In addition, for coating, a method such as a dapping method can be appropriately used.

  The application of the active energy ray-curable adhesive is preferably controlled so that the thickness of the finally formed adhesive layer is 0.05 to 10 μm, and more preferably 0.1 to 5 μm. It is preferable that the thickness is 0.2 to 3 μm.

<Transparent protective film>
As the material constituting the transparent protective film, a material excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like is preferable. For example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetyl cellulose and triacetyl cellulose, acrylic polymers such as polymethyl methacrylate, styrene such as polystyrene and acrylonitrile / styrene copolymer (AS resin) And polymers based on polycarbonate and polycarbonate. In addition, polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure, polyolefin polymers such as ethylene / propylene copolymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, sulfone polymers , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, epoxy polymer, or the above Examples of the polymer that forms the transparent protective film include polymer blends. One or more kinds of arbitrary appropriate additives may be contained in the transparent protective film. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a mold release agent, an anti-coloring agent, a flame retardant, a nucleating agent, an antistatic agent, a pigment, and a coloring agent. The content of the thermoplastic resin in the transparent protective film is preferably 50 to 100% by weight, more preferably 50 to 99% by weight, still more preferably 60 to 98% by weight, and particularly preferably 70 to 97% by weight. . When content of the said thermoplastic resin in a transparent protective film is 50 weight% or less, there exists a possibility that the high transparency etc. which a thermoplastic resin originally has cannot fully be expressed.

  The thickness of the transparent protective film can be appropriately determined, but is generally about 1 to 500 μm from the viewpoints of workability such as strength and handleability, and thin layer properties. 1-300 micrometers is especially preferable, and 5-200 micrometers is more preferable.

<Liquid crystal layer>
The liquid crystal layer is one in which the orientation of the liquid crystal compound is fixed. For example, after applying a liquid crystal compound composition solution containing one or more polymerizable liquid crystal compounds and a solvent to form a coating layer, the coating layer Can be formed by drying.

  The polymerizable liquid crystal compound used in the liquid crystal composition solution is a monomer or an oligomer, and may be used alone or in combination of two or more. The polymerizable liquid crystal compound is preferably a polymerizable nematic liquid crystal compound having one or more polymerizable functional groups per molecule, and particularly preferably an acrylic polymerizable liquid crystal compound. As the acrylic polymerizable liquid crystal compound, a bifunctional acrylic monomer is preferable, and among them, a compound that becomes a main chain type liquid crystal polymer after polymerization is preferable.

  Among such acrylic liquid crystal compounds, a polymerizable acrylic monomer represented by the following general formula (I) or (II) can be particularly preferably used.

In the general formulas (I) and (II), at least one of Y _{1 and} Y ₂ is an acrylate group (CH ₂ ═CHCO—) or a methacrylate group (CH ₂ ═C (CH ₃ ) CO—). Y _1, one of _{Y 2} are, if neither of the acrylate group, methacrylate group, _{Y 1} or _{Y 2} is vinyl group, isopropenyl group, 4-vinylphenyl group, 1-chloroethenyl group, an epoxy group, It may be a polymerizable functional group such as a cyanate group or an isocyanate group, and may be hydrogen, halogen, an alkyl group, an alkoxy group, a cyano group, a nitro group, or the like. Among these, from the viewpoint of the orientation of the liquid crystal compound, both Y ₁ and Y ₂ are preferably polymerizable functional groups, and more preferably both are acrylate groups or methacrylate groups.

X ₁ and X ₂ are each independently a covalent bond, a linear or branched alkylene group, an ether group, a carbonyl group, an ester group, a carbonate group, or a divalent group containing one or more thereof.

  A, B, and C represent substituents, and a, b, and c represent the corresponding numbers of substitutions of A, B, and C (integers from 0 to 3), respectively. A, B, and C are each independently monovalent such as halogen, a linear or branched alkyl group having 1 to 20 carbon atoms, an alkoxy group, an alkoxycarbonyl group, a cyano group, a nitro group, or a hydroxy group. It is the basis of. In addition, the compound represented by the general formula (I) or (II) may have a plurality of the same substituents on the same benzene ring, or may have different substituents. .

In particular, from the viewpoint that the liquid crystal molecules have high birefringence and the liquid crystal coating layer can be thinned, the polymerizable liquid crystal compound preferably contains the compound of the general formula (II). In the compound (II), both Y ₁ and Y ₂ are preferably an acrylate group and a methacrylate group. From the wide temperature range showing a liquid crystal phase, both Y ₁ and Y ₂ are acrylate groups. More preferably. X ₁ and X ₂ are preferably those in which an alkylene group and an ether group, a carbonyl group, an ester group, or a carbonate group are linked, and more preferably, the alkylene has 1 to 12 carbon atoms, More preferably, it is 4-10. When the number of carbon atoms of alkylene is small, liquid crystallinity tends to be low (that is, crystallinity is high). On the other hand, if the alkylene group has too many carbon atoms, the isotropic phase transition temperature of the liquid crystal will be lowered. Therefore, as will be described later, when forming the liquid crystal solidified layer by heating and drying, the orientation of the liquid crystal molecules should be kept uniform. There is a tendency that the temperature range that can be reduced.

  From the above viewpoint, in the method for producing a retardation film of the present invention, it is preferable to use a compound represented by the following general formula (III) among liquid crystalline compounds.

In the above general formula (III), Z is hydrogen, halogen, an alkyl group having 1 to 4 carbon atoms, an alkoxy group, a cyano group, or a nitro group, and is preferably a chlorine or methyl group. R ₁ and R ₂ are each independently hydrogen or a methyl group, but it is preferable that both R ₁ and R ₂ are hydrogen. X ₃ and X ₄ are each independently an ether group, a carbonyl group, an ester group, or a carbonate group.

  As the solvent used in the liquid crystal composition solution, the composition containing the polymerizable liquid crystal monomer and the polymerization initiator is excellent in solubility, and when the composition is applied to a substrate, the wettability and composition of the substrate There is no particular limitation as long as it does not cause a decrease in the orientation of the product.

  Specifically, as the solvent, for example, aromatic hydrocarbons such as benzene, toluene, xylene, methoxybenzene, 1,2-dimethoxybenzene, chloroform, dichloromethane, carbon tetrachloride, dichloroethane, tetrachloroethane, trichloroethylene, tetrachloroethylene Halogenated hydrocarbons such as chlorobenzene and orthodichlorobenzene, phenols such as phenol and parachlorophenol, ethers such as diethyl ether, dibutyl ether, tetrahydrofuran, anisole, dioxane, tetrahydrofuran, acetone, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone Cyclopentanone, 2-pentanone, 3-pentanone, 2-hexanone, 3-hexanone, 2-heptanone, 3-heptanone, Ketones such as heptanone, 2,6-dimethyl-4-heptanone, 2-pyrrolidone, N-methyl-2-pyrrolidone, n-butanol, 2-butanol, cyclohexanol, isopropyl alcohol, t-butyl alcohol, glycerin, Ethylene glycol, triethylene glycol, ethylene glycol monomethyl ether, diethylene glycol dimethyl ether, propylene glycol, dipropylene glycol, alcohols such as 2-methyl-2,4-pentanediol, amides such as dimethylformamide, dimethylacetamide, acetonitrile, butyronitrile Nitriles such as, cellosolves such as methyl cellosolve and methyl cellosolve, and esters such as ethyl acetate, butyl acetate and methyl lactate can be used. In addition, methylene chloride, carbon disulfide, ethyl cellosolve, butyl cellosolve, and the like can be given as examples of the solvent, but are not limited thereto.

  In addition, from the viewpoint of sufficiently dissolving the above composition without substantially eroding the substrate, cyclopentanone, cyclohexanone, methyl isobutyl ketone, methyl ethyl ketone, tetrahydrofuran, toluene, or ethyl acetate is used as the solvent. Is preferred.

  These solvents may be used alone or in admixture of two or more. The total solid concentration of the mixed solution varies depending on the solubility, coating viscosity, wettability on the substrate, thickness after coating, etc., but in order to obtain a highly smooth retardation film, the solid concentration is It is preferably 2 to 50% by weight, preferably 5 to 45% by weight, and more preferably 10 to 40% by weight.

  Moreover, it is preferable to use a photoinitiator from the viewpoint of increasing the polymerization rate and reaction rate of the polymerizable liquid crystal compound. There is no restriction | limiting in particular as a photoinitiator, The photoinitiator which consists of a single compound may be sufficient, and what mixed two or more types of different photoinitiators may be sufficient. Examples of the photopolymerization initiator include acetophenone compounds, benzoin compounds, benzophenone compounds, thioxanthone compounds, and the like. Further, for example, trade names “Irgacure 651”, “Irgacure 184”, “Darocur 1173”, “Irgacure 500”, “Irgacure 2959”, “Irgacure 907”, “Irgacure 369”, “Irgacure 369”, manufactured by Ciba Specialty Chemicals Photopolymerization initiators such as “Irgacure 819” and “Irgacure 784” may be used. Further, Merck's trade names “Darocur 953” and “Darocur 1116”, and Nippon Kayaku's trade names “Kaya Cure MBP”, “Kaya Cure CTX”, “Kaya Cure DITX”, “Kaya Cure CTX”, “Kaya Cure DETX” It is also possible to use “Kayacure RTX” or the like.

  In addition, an auxiliary agent may be added to the photopolymerization initiator in order to accelerate the polymerization reaction. Examples of the auxiliary agent include triethanolamine, methyldiethanolamine, triisopropanolamine, n-butylamine, N-methyldiethanolamine, diethylaminoethyl methacrylate, Michler's ketone, 4,4′-diethylaminophenone, ethyl 4-dimethylaminobenzoate, Examples thereof include amine compounds such as 4-dimethylaminobenzoic acid (nbutoxy) ethyl and 4-dimethylaminobenzoic acid isoamyl.

  Although there is no restriction | limiting in particular in the addition amount of the said photoinitiator, It is preferable that it is 0.5-20 weight part with respect to 100 weight part of said polymeric liquid crystal compounds, and it is 2-15 weight part. Is more preferable. Moreover, it is preferable that the addition amount of an adjuvant shall be about 0.5 to 2 times amount with respect to a photoinitiator.

  Moreover, additives, such as a leveling agent and a polymerization inhibitor, can also be added to the liquid crystal composition solution. The addition amount of additives such as a leveling agent and a polymerization inhibitor is preferably 0.001 to 3 parts by weight, more preferably 0.01 to 2 parts by weight with respect to 100 parts by weight of the polymerizable liquid crystal compound. .

  In the liquid crystal layer of the present invention, the liquid crystal composition solution is applied onto a substrate to form a coating layer. The base material is used to uniformly develop the polymerizable liquid crystal compound and other compositions in the solution, and then obtain a uniform alignment state.

  Examples of the material for forming the base material include the same materials as the transparent protective film. Other metal substrates such as aluminum, iron and copper, glass substrates such as blue plate glass, alkali glass, alkali-free glass, borosilicate glass, flint glass and quartz glass, various substrates such as ceramic substrates, silicon wafers, etc. Various semiconductor base materials and the like can also be mentioned. Finally, when the liquid crystal layer is transferred from the base material, the surface of the base material can be subjected to a peeling treatment.

  The substrate may have birefringence or may not have birefringence. When there is no birefringence, the phase difference is expressed only by the birefringence of the obtained liquid crystal layer, so that the control of the optical characteristics becomes easy. On the contrary, by using a substrate having birefringence, a phase difference caused by both the birefringence of the substrate and the birefringence of the liquid crystal layer can be obtained.

  An application layer is formed by applying the polymerizable liquid crystal compound onto a substrate. From the viewpoint of increasing the uniformity of orientation on the substrate, the substrate is preferably subjected to orientation treatment. Examples of the alignment treatment method include rubbing treatment, oblique vapor deposition treatment, microgroove method, stretched polymer film method and the like. From the viewpoint of the ease of the manufacturing process and the high uniformity of alignment, it is preferable to use a rubbing process as the alignment process method.

  The alignment film used for the rubbing treatment is not particularly limited, but is preferably one that is excellent in the wettability of the liquid crystal composition solution and can align the polymerizable liquid crystal compound in a specific direction. As such an alignment film, specifically, for example, polyamide, polyimide, lecithin, silica, polyvinyl alcohol, ester-modified polyvinyl alcohol, a polymer in which the degree of saponification of polyvinyl acetate is adjusted, a silane coupling agent, or the like is applied. An alignment film formed as described above can be given. The surface of the substrate may be rubbed as it is.

The method for applying the liquid crystal composition solution to the substrate is not particularly limited, and a conventionally known method can be used. For example, the solution may be developed into a thin layer by spin coating, roll coating, flow coating, printing, dip coating, casting film formation, bar coating, gravure printing, or the like. The coating thickness after drying is usually 0.1 to 30 μm, more preferably 0.2 to 20 μm, and particularly preferably 0.3 to 10 μm.
it changed.

  Control of the retardation of the liquid crystal layer is not particularly limited. For example, the front retardation can be designed to be 90 to 190 nm. If it is in the range of the front phase difference, it can function as a λ / 4 plate. The phase difference value can be measured by the following method.

  The liquid crystal layer has a front phase difference and can be controlled to have a plurality of regions each having a slow axis in a different direction in a predetermined pattern. For example, by fixing the alignment of the liquid crystalline compound using a mask pattern or the like, a liquid crystal layer having a different alignment state for each micro region can be formed. The polarizing element having such a liquid crystal layer can be applied to, for example, a space-division type three-dimensional display in which a right-eye image and a left-eye image are displayed for each pixel.

(Phase difference value)
The phase difference value is measured using a phase difference meter based on the parallel Nicol rotation method (product name “KOBRA-CCD” manufactured by Oji Scientific Instruments Co., Ltd.) with respect to a wavelength of 590 nm. The phase difference was measured.

  The liquid crystal layer is provided with a hydrophilic layer, but an easy adhesion treatment can be performed before the hydrophilic layer is provided. Examples of the easy adhesion treatment include dry treatment such as plasma treatment and corona treatment, chemical treatment such as alkali treatment, and coating treatment for forming an easy adhesive layer.

<Hydrophilic layer>
The hydrophilic layer is provided between the adhesive layer and the liquid crystal layer to improve the adhesion of these layers. As a material for forming the hydrophilic layer, for example, various resins such as ester, ether, carbonate, urethane, and organosilicon compounds can be used. The hydrophilic layer may be either water-based or solvent-based. Of these, urethane resins and organosilicon compounds are preferred.

  As the organosilicon compound, those having an unsaturated double bond such as a (meth) acryloyl group and a vinyl group are preferable, and a compound having a (meth) acryloyl group is particularly preferable. Examples of such organosilicon compounds include silane coupling agent-based unsaturated monomers having at least one unsaturated double bond such as a (meth) acryloyl group and a vinyl group and an alkoxysilyl group. . The silane coupling agent-based unsaturated monomer includes a silane coupling agent-based (meth) acrylate monomer, a silane coupling agent-based vinyl monomer, and the like.

  Examples of the silane coupling agent (meth) acrylate monomer include (meth) acryloyloxymethyl-trimethoxysilane, (meth) acryloyloxymethyl-triethoxysilane, 2- (meth) acryloyloxyethyl-trimethoxysilane, 2- (meth) acryloyloxyethyl-triethoxysilane, 3- (meth) acryloyloxypropyl-trimethoxysilane, 3- (meth) acryloyloxypropyl-triethoxysilane, 3- (meth) acryloyloxypropyl-tripropoxy (Meth) acryloyloxyalkyl-trialkoxysilane, such as silane, 3- (meth) acryloyloxypropyl-triisopropoxysilane, 3- (meth) acryloyloxypropyl-tributoxysilane; , (Meth) acryloyloxymethyl-methyldimethoxysilane, (meth) acryloyloxymethyl-methyldiethoxysilane, 2- (meth) acryloyloxyethyl-methyldimethoxysilane, 2- (meth) acryloyloxyethyl-methyldiethoxysilane 3- (meth) acryloyloxypropyl-methyldimethoxysilane, 3- (meth) acryloyloxypropyl-methyldiethoxysilane, 3- (meth) acryloyloxypropyl-methyldipropoxysilane, 3- (meth) acryloyloxypropyl -Methyldiisopropoxysilane, 3- (meth) acryloyloxypropyl-methyldibutoxysilane, 3- (meth) acryloyloxypropyl-ethyldimethoxysilane, 3- (meth) acryloyloxy Propyl-ethyldiethoxysilane, 3- (meth) acryloyloxypropyl-ethyldipropoxysilane, 3- (meth) acryloyloxypropyl-ethyldiisopropoxysilane, 3- (meth) acryloyloxypropyl-ethyldibutoxysilane, (Meth) acryloyloxyalkyl-alkyldialkoxysilanes such as 3- (meth) acryloyloxypropyl-propyldimethoxysilane and 3- (meth) acryloyloxypropyl-propyldiethoxysilane, and (meth) acryloyloxy corresponding thereto Alkyl-dialkyl (mono) alkoxysilane and the like can be mentioned.

  Examples of the silane coupling agent vinyl monomer include vinyltrialkoxysilanes such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, and vinyltributoxysilane. Corresponding vinylalkyl dialkoxysilanes and vinyldialkylalkoxysilanes such as vinylmethyltrimethoxysilane, vinylmethyltriethoxysilane, β-vinylethyltrimethoxysilane, β-vinylethyltriethoxysilane, γ-vinylpropyltrimethoxy Vinyl, such as silane, γ-vinylpropyltriethoxysilane, γ-vinylpropyltripropoxysilane, γ-vinylpropyltriisopropoxysilane, γ-vinylpropyltributoxysilane Other alkyltrialkoxysilane, these correspond and (vinyl) alkyl dialkoxy silanes, and the like (vinyl alkyl) dialkyl (mono) alkoxysilanes.

  A polyurethane resin or a urethane prepolymer is used as the urethane resin. The polyurethane resin is a polyurethane or a modified product obtained by reacting a chain extender and a chain terminator as necessary, with a polyol component and a polyisocyanate component as main components. The urethane prepolymer generally comprises a polyol component and a polyisocyanate component as main components and has an isocyanate group or a blocked isocyanate group at the terminal.

  Examples of the polyol component include polyether polyols such as polyethylene glycol, polypropylene glycol and polyoxytetramethylene ether glycol obtained by ring-opening polymerization of ethylene oxide, propylene oxide, tetrahydrofuran and the like; ethylene glycol, diethylene glycol, triethylene glycol, 1, 2 -Propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, Saturated or unsaturated various known low molecular glycols such as octanediol, 1,4-butynediol, dipropylene glycol, bisphenol A, hydrogenated bisphenol A; Molecular glycols and dibasic acids such as adipic acid, maleic acid, fumaric acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, azelaic acid, sebacic acid, suberic acid Polyester polyols obtained by dehydration condensation of acids or acid anhydrides corresponding thereto; polyester polyols obtained by ring-opening polymerization of lactones such as ε-caprolactone and β-methyl-δ-valerolactone; Various known polymer polyols generally used for the production of polyurethane such as polycarbonate polyols and polybutadiene glycols are exemplified. In addition, a part of the low molecular glycol component is various polyols such as glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1,2,4-butanetriol, pentaerythritol, sorbitol and the like. You can also.

  As the polyisocyanate compound, various known aromatic, aliphatic or alicyclic diisocyanates can be used. For example, 1,5-naphthylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-diphenyldimethylmethane diisocyanate, 4,4′-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3- Phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4- Trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate Isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, 1,3-bis (isocyanatemethyl) cyclohexane, methylcyclohexane diisocyanate, m-tetramethylxylylene diisocyanate, and the carboxyl group of dimer acid were converted to isocyanate groups. A typical example is dimer isocyanate.

  Examples of isocyanate group blocking agents include bisulfites and sulfonic acid group-containing phenols, alcohols, lactam oximes, and active methylene compounds.

  Examples of the chain extender include various known low molecular glycols listed in the description of the polyester diol; ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4. Examples include amines such as' -diamine and water. In addition, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, etc. Representative examples include diamines having a hydroxyl group; dimer diamine obtained by converting a carboxyl group of dimer acid into an amino group, and the like.

  Examples of the chain terminator include monoamines such as monobutylamine and dibutylamine; monoamines having a hydroxyl group such as monoethanolamine and diethanolamine; monoamines having a primary alcoholic hydroxyl group such as ethanol and n-butanol. Examples include alcohols.

  The polyurethane resin can be appropriately used as a solution. As the polyurethane resin, a resin that is dissolved in an organic solvent inert to an isocyanate group or the like and dispersed or dissolved in water can be used. The water-based dispersibility or solubility is, for example, by introducing a hydrophilic group such as a carboxylate, a sulfonate group or a sulfate half ester base into a polyurethane or urethane prepolymer, or an ethylene oxide adduct. It is performed by using a polyol component having a hydrophilic part such as.

  For introducing a hydrophilic group such as a carboxylate into a polyurethane or urethane prepolymer, for example, a carboxyl group-containing diol is used as a diol component. As the carboxyl group-containing diol, α, α′-dimethylolalkanoic acid (glyceric acid, dimethylolpropionic acid, dimethylolbutanoic acid, 2,2-dimethylolpentanoic acid, etc.), dioxymaleic acid, dioxyfumaric acid, tartaric acid 2,6-dioxybenzoic acid, 4,4-bis (hydroxyphenyl) valeric acid, 4,4-bis (hydroxyphenyl) butyric acid, etc., and ε-caprolactone and γ-butyrolactone using these carboxyl group-containing diols as initiators And those obtained by ring-opening polymerization of lactones such as γ-valerolactone.

  In addition to the above, examples of the hydrophilic group-introducing component include amino group or hydroxyl group-containing carboxylic acid and amino group or hydroxyl group-containing sulfonic acid. Examples of the amino group-containing carboxylic acid include β-aminopropionic acid, γ-aminobutyric acid, p-aminobenzoic acid, and the like. Examples of the hydroxyl group-containing carboxylic acid include 3-hydroxypropionic acid, γ-hydroxybutyric acid, Examples thereof include p- (2-hydroxyethyl) benzoic acid and malic acid. Examples of the compound having an amino group or a hydroxyl group and a sulfonic acid group include aminomethanesulfonic acid, 2-aminoethanesulfonic acid, and 2-amino-5. -Methylbenzene-2-sulfonic acid, sodium β-hydroxyethanesulfonate, propane sultone and butane sultone addition products of aliphatic diprimary amine compounds. Furthermore, examples of the compound containing an amino group or a hydroxyl group and a sulfuric acid half ester group include aminoethanol sulfate, aminobutanol sulfate, hydroxyethanol sulfate, α-hydroxybutanol sulfate and the like.

  Further, for neutralization of the carboxyl group, alkali metals such as potassium hydroxide and sodium hydroxide, ammonia or trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, N-alkyldiethanolamine, N, N ′ -Tertiary amines such as dialkyl monoethanolamine are used.

  Moreover, you may add another additive to the said hydrophilic layer. Specifically, terpene resins, phenol resins, terpene-phenol resins, rosin resins, xylene resins and other tackifiers, UV absorbers, antioxidants, heat stabilizers and other stabilizers may be used.

  The hydrophilic layer is formed by coating and drying a solution diluted to an appropriate concentration in consideration of the thickness after drying, the smoothness of coating, and the like by a known technique. The hydrophilic layer has a thickness after drying of preferably 0.1 to 1000 nm, more preferably 0.2 to 800 nm. Even when a plurality of hydrophilic layers are provided, the total thickness of the hydrophilic layers is preferably within the above range. The hydrophilic layer is usually formed on the liquid crystal layer, and may be formed as a single layer, or a part thereof may penetrate into the liquid crystal layer.

<Manufacture of polarizing element>
In the production of the polarizing element of the present invention, for example, a liquid crystal layer is formed on a base material with or without a modified layer, and a hydrophilic layer is formed on the liquid crystal layer. After forming a modified layer / liquid crystal layer / hydrophilic layer or substrate / liquid crystal layer / hydrophilic layer laminate, the hydrophilic layer and the polarizer of the laminate can be bonded together with an adhesive layer. . The substrate can be used as it is as a transparent protective film, and when the substrate is a release film, the liquid crystal layer / hydrophilic layer can be transferred to the polarizer via an adhesive layer.

  The adhesive is hydrophilic on the surface of the polarizer forming the adhesive layer and / or the laminate (base material / modified layer / liquid crystal layer / hydrophilic layer or base material / liquid crystal layer / hydrophilic layer). After coating on the layer surface, bonding is performed via the adhesive.

  The adhesive coating method is appropriately selected depending on the viscosity of the adhesive and the target thickness. Examples of the coating method include a reverse coater, a gravure coater (direct, reverse or offset), a bar reverse coater, a roll coater, a die coater, a bar coater, a rod coater, and the like. In addition, for coating, a method such as a dapping method can be appropriately used.

  A polarizer and a transparent protective film are bonded together through the adhesive applied as described above. Bonding of the polarizer and the transparent protective film can be performed with a roll laminator or the like.

  After the bonding with the adhesive, the adhesive is cured to form an adhesive layer according to the type of the adhesive. For example, when an active energy ray curable adhesive is used, an active energy ray is irradiated to form an adhesive layer. Examples of the active energy rays include ultraviolet rays and electron beams.

When the ultraviolet curable adhesive is employed, any appropriate condition can be adopted as the ultraviolet irradiation condition as long as the adhesive can be cured. The dose of ultraviolet rays is preferably from 700~2000mJ / cm ² in accumulated light quantity, and even more preferably 900~1500mJ / cm ^2.

  When the electron beam curable adhesive is employed, any appropriate conditions can be adopted as the irradiation condition of the electron beam as long as the adhesive can be cured. For example, in the electron beam irradiation, the acceleration voltage is preferably 5 kV to 300 kV, and more preferably 10 kV to 250 kV. If the acceleration voltage is less than 5 kV, the electron beam may not reach the adhesive and may be insufficiently cured. If the acceleration voltage exceeds 300 kV, the penetration force through the sample is too strong and the electron beam rebounds, There is a risk of damaging the polarizer. The irradiation dose is 5 to 100 kGy, more preferably 10 to 75 kGy.

  Electron beam irradiation is usually performed in an inert gas, but if necessary, it may be performed in the atmosphere or under a condition in which a small amount of oxygen is introduced. Depending on the material of the transparent protective film, by appropriately introducing oxygen, the transparent protective film surface where the electron beam first hits can be obstructed to prevent oxygen damage and prevent damage to the transparent protective film. An electron beam can be irradiated efficiently.

  The polarizing element of the present invention can be used as an optical film laminated with another optical layer in practical use. The optical layer is not particularly limited. For example, for forming a liquid crystal display device such as a reflection plate, a semi-transmission plate, a retardation plate (including wavelength plates such as 1/2 and 1/4), and a viewing angle compensation film. One or more optical layers that may be used can be used.

  An optical film in which the optical layer is laminated on a polarizing plate can be formed by a method of sequentially laminating separately in the manufacturing process of a liquid crystal display device or the like. There is an advantage that the manufacturing process of a liquid crystal display device or the like can be improved because of excellent stability and assembly work. For the lamination, an appropriate adhesive means such as an adhesive layer can be used. When adhering the polarizing element and other optical films, their optical axes can be set at an appropriate arrangement angle in accordance with the target retardation characteristics.

  An adhesive layer for adhering to other members such as a liquid crystal cell may be provided on the polarizing element described above or an optical film in which at least one polarizing element is laminated. The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is not particularly limited. For example, an acrylic polymer, silicone-based polymer, polyester, polyurethane, polyamide, polyether, fluorine-based or rubber-based polymer is appropriately selected. Can be used. In particular, those having excellent optical transparency such as an acrylic pressure-sensitive adhesive, exhibiting appropriate wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties, and being excellent in weather resistance, heat resistance and the like can be preferably used.

  Attaching the adhesive layer to one side or both sides of the polarizing element or the optical film can be performed by an appropriate method. For example, a pressure-sensitive adhesive solution of about 10 to 40% by weight in which a base polymer or a composition thereof is dissolved or dispersed in a solvent composed of an appropriate solvent alone or a mixture such as toluene and ethyl acetate is prepared. A method in which it is directly attached on a polarizing element or an optical film by an appropriate development method such as a casting method or a coating method, or an adhesive layer is formed on a separator in accordance with the above, and this is applied to a polarizing element or an optical film The method of moving up is mentioned.

  The pressure-sensitive adhesive layer can be provided on one side or both sides of a polarizing element or an optical film as a superimposed layer of different compositions or types. Moreover, when providing in both surfaces, it can also be set as the adhesion layers of a different composition, a kind, thickness, etc. in the front and back of a polarizing element or an optical film. The thickness of the pressure-sensitive adhesive layer can be appropriately determined according to the purpose of use and adhesive force, and is generally 1 to 500 μm, preferably 5 to 200 μm, particularly preferably 10 to 100 μm.

  On the exposed surface of the adhesive layer, a separator is temporarily attached and covered for the purpose of preventing contamination until it is put to practical use. Thereby, it can prevent contacting an adhesion layer in the usual handling state. As the separator, except for the above thickness conditions, for example, a suitable thin leaf body such as a plastic film, rubber sheet, paper, cloth, non-woven fabric, net, foam sheet, metal foil, laminate thereof, and the like, silicone type or Appropriate conventional ones such as those coated with an appropriate release agent such as long-chain alkyl, fluorine-based, or molybdenum sulfide can be used.

  In the present invention, the polarizer, transparent protective film, optical film, and the like that form the polarizing element described above, and each layer such as an adhesive layer include, for example, salicylic acid ester compounds, benzophenol compounds, benzotriazole compounds, and cyanoacrylates. It may be a compound having an ultraviolet absorbing ability by a method such as a method of treating with an ultraviolet absorber such as a compound based on nickel or a nickel complex salt compound.

  The polarizing element or the optical film of the present invention can be preferably used for forming various devices such as a liquid crystal display device. The liquid crystal display device can be formed according to the conventional method. In other words, a liquid crystal display device is generally formed by appropriately assembling components such as a liquid crystal cell, a polarizing element or an optical film, and an illumination system as necessary, and incorporating a drive circuit. There is no limitation in particular except the point which uses the polarizing element or optical film by invention, and it can apply according to the former. As the liquid crystal cell, any type such as a TN type, an STN type, or a π type can be used.

  An appropriate liquid crystal display device such as a liquid crystal display device in which a polarizing element or an optical film is disposed on one side or both sides of a liquid crystal cell, or a backlight or a reflecting plate used in an illumination system can be formed. In that case, the polarizing element or optical film by this invention can be installed in the one side or both sides of a liquid crystal cell. When providing a polarizing element or an optical film on both sides, they may be the same or different. Further, when forming the liquid crystal display device, for example, a single layer or a suitable layer such as a diffusing plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffusing plate, a backlight, etc. Two or more layers can be arranged.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1
(Preparation of liquid crystal composition solution)
A polymerizable liquid crystal compound (manufactured by BASF, trade name “Pariocolor LC242”) was dissolved in cyclopentanone to prepare a solution having a solid content of 30% by weight. To this solution, a surfactant (BIC Chemie, trade name “BYK-360”) and a polymerization initiator (Ciba Specialty Chemicals, trade name “Irgacure 369”) are added to obtain a liquid crystal composition. A solution was prepared. The addition amount of the leveling agent and the polymerization initiator was 0.01 parts by weight and 3 parts by weight, respectively, with respect to 100 parts by weight of the polymerizable liquid crystal compound.

(Formation of liquid crystal layer 1)
≪Oriented substrate≫
A triacetyl cellulose film (manufactured by Fuji Film Co., Ltd., trade name “TD60UL”, thickness 60 μm) was saponified and then rubbed with a rayon rubbing cloth was used as the alignment substrate.

≪Formation of modified layer≫
An aqueous solution in which pure water and acetic anhydride were mixed at a weight ratio of 1.88: 1 was prepared. While stirring this aqueous solution at a stirring speed of 300 rpm, 3-acryloxypropyltrimethoxysilane (“trade name” KBM5103, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to the aqueous solution at a dropping rate of 10 ml / min. The weight ratio of the aqueous solution to 3-acryloxypropyltrimethoxysilane was 2.88: 0.2. Further, after the aqueous solution was stirred for 10 minutes, isopropyl alcohol was added to the aqueous solution so that the organosilicon compound concentration was 1% by weight, and the solution was further stirred for 1 minute to prepare a modified layer forming solution. The modified layer forming solution was applied to the rubbing-treated surface of the alignment substrate using a bar coater (# 3), and then dried in an oven at 120 ° C. for 5 minutes to form a modified layer ( Thickness 10 nm).

≪Formation of liquid crystal layer≫
Next, the liquid crystal composition solution was uniformly coated on the modified layer using a wire bar (coating wet thickness: about 4 μm) to form a coating layer. Next, the coating layer was dried for 2 minutes in an air circulating constant temperature oven at 90 ° C. together with the alignment substrate, and the liquid crystalline compound solidified the homogeneous alignment to form a liquid crystal layer 1 having a thickness of 1.4 μm. When the front phase difference of the liquid crystal layer 1 was measured, it was 140 nm.

(Preparation of organosilicon compound solution)
30 parts by weight of 3-acryloxypropyltrimethoxysilane having a double bond (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KBM-5103”) is diluted with 70 parts by weight of isopropyl alcohol to prepare an organosilicon compound solution. Prepared.

(Formation of hydrophilic layer 1)
After the corona treatment of the surface of the liquid crystal layer 1 provided on the triacetyl cellulose film, the organosilicon compound solution is applied using a wire bar and dried in an oven at 100 ° C. for 2 minutes. A hydrophilic layer 1 having a thickness of 30 nm was formed.

(Production of polarizer)
A polyvinyl alcohol film having an average polymerization degree of 2400, a saponification degree of 99.9 mol%, and a thickness of 75 μm was immersed in warm water at 30 ° C. for 60 seconds to swell. Subsequently, the film was stretched to 3.5 times while dyeing in an iodine solution of 0.3 wt% (weight ratio: iodine / potassium iodide = 0.5 / 8) at 30 ° C. for 1 minute. Then, the total draw ratio was drawn up to 6 times while being immersed in a 4% by weight borate aqueous solution at 65 ° C. for 0.5 minutes. After stretching, drying was performed in an oven at 70 ° C. for 3 minutes to obtain a polarizer having a thickness of 26 μm.

(Preparation of adhesive)
As an adhesive, 35 parts by weight of N-hydroxyethylacrylamide (manufactured by Kojin Co., Ltd.), 45 parts by weight of N-acryloylmorpholine (manufactured by Kojin Co., Ltd.), polypropylene glycol diacrylate (manufactured by Toa Gosei Co., Ltd., “trade name” Aronix) 25 parts by weight of M-220), 3 parts by weight of a photopolymerization initiator (Ciba Specialty Chemicals, trade name “Irgacure 184”), and another photopolymerization initiator (Nippon Kayaku Co., Ltd.) 1.5 parts by weight of a product name “KAYACUREDETX-S”) was added.

(Preparation of polarizing element)
The adhesive was applied on the hydrophilic layer 1 of the liquid crystal layer and the hydrophilic layer 1 sequentially provided on the triacetyl cellulose film. Moreover, the said adhesive agent was apply | coated on the 40-micrometer-thick acrylic film used as a transparent protective film. The coating thickness was about 500 nm in all cases. The films after bonding to both surfaces of the polarizer, conveyor type UV irradiation device (fusion Co.), a peak UV irradiance; UV at 1000 mJ / cm ² (wavelength ^{380~440nm); 1600mW / cm 2,} UV accumulated light amount It was cured and further dried at 70 ° C. for 2 minutes to obtain a polarizing element. The structure of the obtained polarizing element corresponds to FIG. 1 (however, it has a modified layer).

Example 2
In Example 1 (formation of the liquid crystal layer 1), in the same manner as in Example 1 except that the liquid crystal layer 2 was formed instead of forming the liquid crystal layer 1 on the modified layer of the alignment substrate, polarization was performed. An element was produced.

(Formation of liquid crystal layer 2)
A triacetyl cellulose film (Fuji Film Co., Ltd., “TD60UL”, thickness 60 μm) was saponified and then rubbed in a 45 ° direction with respect to the longitudinal direction of the film using a rayon rubbing cloth. Thereafter, a masking tape was bonded at intervals of 0.4 mm, and a rubbing treatment in a direction different by 90 ° from the rubbing direction was used as an alignment substrate. The liquid crystal composition solution used in Example 1 was uniformly applied to the rubbing-treated surface of the alignment substrate using a wire bar (application wet thickness: about 4 μm) to form an application layer. Next, the coating layer was dried together with an alignment substrate in a 90 ° C. air circulation type thermostatic oven for 2 minutes to solidify the alignment of the liquid crystal compound to form a liquid crystal layer 2 having a thickness of 1.4 μm. The liquid crystal layer 2 had a slow axis angle shifted by 90 ° at intervals of 0.4 mm, and the front phase difference was 140 nm.

Example 3
In Example 1 (formation of hydrophilic layer 1), instead of forming hydrophilic layer 1, using the following polyester urethane solution, except that hydrophilic layer 2 was formed, the same as in Example 1, A polarizing element was produced.

(Preparation of polyester urethane solution)
Polyester urethane (“trade name”: Superflex 210, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., solid content: 33% by weight) 16.8 parts by weight, cross-linking agent (“trade name”: Epocross WS-700, manufactured by Nippon Shokubai Chemical Co., Ltd., (Oxazoline-containing polymer, solid content: 25% by weight) 4.2 parts by weight, 2.0% by weight of 1% by weight of ammonia water, and 76.6 parts by weight of pure water were mixed to prepare a polyester urethane solution.

(Preparation of hydrophilic layer 2)
After the corona treatment of the surface of the liquid crystal layer 1 provided on the triacetyl cellulose film, the polyester urethane solution is applied using a wire bar, dried in an oven at 150 ° C. for 1 minute, and thick on the surface of the liquid crystal layer 1. A hydrophilic layer 2 having a thickness of 300 nm was formed.

Example 4
In Example 1 (formation of the liquid crystal layer 1), instead of forming the liquid crystal layer 1 on the alignment substrate, the liquid crystal layer 2 described in Example 2 was formed; instead of forming the hydrophilic layer 1, A polarizing element was produced in the same manner as in Example 1 except that the hydrophilic layer 2 was formed using the polyester urethane solution described in Example 3.

[Evaluation]
The following evaluation was performed about the polarizing element obtained by the Example and the comparative example. The results are shown in Table 1.

<Evaluation of adhesiveness>
A cutter was inserted between the liquid crystal layer and the polarizer of the polarizing element obtained in Examples and Comparative Examples, and a peel test was performed. In the peel test, “○” indicates that the alignment substrate was broken (that is, good adhesion between the polarizer and the liquid crystal layer), and x indicates that the both peeled off and peeled at the interface between the polarizer and the liquid crystal layer. The adhesion between the element and the liquid crystal interface was poor.

<Evaluation for 3D>
The polarizing elements obtained in Examples 2 and 4 were bonded to 3D-TV (model number: 32LW4500, manufactured by LGDisplay). About 3D-TV which bonded the polarizing element of Example 2, 4, it visually confirmed using the circularly-polarizing plate, and it confirmed that a three-dimensional image was visible.

P Polarizer T, T ′ Transparent protective film A, A ′ Adhesive layer B Hydrophilic layer C Liquid crystal layer

Claims (12)

  Polarized light characterized in that a liquid crystal layer in which the orientation of the liquid crystal compound is fixed is provided on at least one surface of the polarizer through an adhesive layer and a hydrophilic layer in this order from the polarizer side. element.   The polarizing element according to claim 1, wherein the hydrophilic layer is formed of an organosilicon compound or a urethane resin.   The polarizing element according to claim 2, wherein the organosilicon compound has a double bond.   The polarizing element according to claim 3, wherein the double bond of the organosilicon compound is a (meth) acryloyl group.   The said adhesive bond layer is formed by the hardened | cured material layer obtained by irradiating active energy ray-curable adhesive to active energy, The Claim 1 characterized by the above-mentioned. Polarizing element.   The polarizing element according to claim 1, wherein the active energy ray-curable adhesive contains a radical polymerizable compound.   The polarizing element according to claim 1, wherein the radical polymerizable compound contains an N-substituted amide monomer.   The polarizing element according to claim 1, wherein a front phase difference of the liquid crystal layer is 90 to 190 nm.   The liquid crystal layer has a front phase difference, and has a plurality of regions each having a slow axis in a different direction in a predetermined pattern. Polarizing element.   The polarizing element according to claim 1, wherein the liquid crystal layer has a transparent protective film on the side opposite to the side on which the hydrophilic layer is provided.   An optical film, wherein at least one polarizing element according to claim 1 is laminated.   An image display device comprising the polarizing element according to claim 1 or the optical film according to claim 11.

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