JP6876544B2 - Adhesive polarizing plate and image display device - Google Patents

Description

The present invention relates to a polarizing plate and a pressure-sensitive polarizing plate having a pressure-sensitive adhesive layer provided on the polarizing plate. Furthermore, the present invention relates to an image display device such as a liquid crystal display device, an organic EL display device, and a PDP using the adhesive polarizing plate.

In a liquid crystal display device or the like, it is indispensable to arrange polarizing elements on both sides of a liquid crystal cell due to the image forming method, and generally, a polarizing plate is attached. When the polarizing plate is attached to the liquid crystal cell, an adhesive is usually used. Further, in order to reduce the loss of light, the polarizing plate and the liquid crystal cell are usually adhered to each other by using an adhesive. In such a case, since it has an advantage that a drying step is not required to fix the polarizing plate, the pressure-sensitive adhesive is a pressure-sensitive polarizing plate provided in advance as a pressure-sensitive adhesive layer on one side of the polarizing plate. Commonly used. A release film is usually attached to the pressure-sensitive adhesive layer of the pressure-sensitive polarizing plate.

At the time of manufacturing a liquid crystal display device, when the adhesive polarizing plate is attached to a liquid crystal cell, the release film is peeled from the adhesive layer of the adhesive polarizing plate, but static electricity is generated by the peeling of the release film. .. The static electricity generated in this way affects the orientation of the liquid crystal inside the liquid crystal display device and causes defects. In addition, display unevenness may occur due to static electricity when using the liquid crystal display device. The generation of static electricity can be suppressed, for example, by forming an antistatic layer on the outer surface of the polarizing plate, but the effect is small and there is a problem that the generation of static electricity cannot be fundamentally prevented. Therefore, in order to suppress the generation of static electricity at the fundamental position, it is required to impart an antistatic function to the adhesive layer. As a means for imparting an antistatic function to the pressure-sensitive adhesive layer, for example, it has been proposed to add an ionic compound to the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer (Patent Documents 1 to 4). Patent Document 1 is a lithium salt, Patent Document 2 is at least one of an alkali metal salt and an alkaline earth metal salt, Patent Document 3 is an ionic compound having an organic cation and being solid at room temperature, and Patent Document 4 is an imidazolium cation. It is described that an ionic solid containing an inorganic anion is blended with an acrylic pressure-sensitive adhesive used for a polarizing plate. Further, a method of providing an antistatic layer between a polarizing plate and an adhesive layer by using a binder of a conductive polymer such as polythiophene has been proposed (Patent Document 5). Further, the adhesive polarizing plate is required to have durability in an adhesive state.

JP-A-2010-189489 Japanese Unexamined Patent Publication No. 2010-065217 Japanese Unexamined Patent Publication No. 2010-066756 Japanese Unexamined Patent Publication No. 2009-251281 Japanese Unexamined Patent Publication No. 2003-246874

In Patent Documents 1 to 4, an antistatic function is imparted by applying a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition containing an ionic compound to a polarizing plate. As the polarizing plates applied in Patent Documents 1 to 4, those having a protective base material such as a transparent protective film on both sides of the polarizer are used.

On the other hand, as the adhesive polarizing plate, an adhesive polarizing plate provided with an adhesive layer may be used without providing a transparent protective film on only one side of the polarizer and without providing a transparent protective film on the other side. Since such a pressure-sensitive polarizing plate has a transparent protective film on only one side, the cost for one layer of the transparent protective film can be reduced as compared with the case where the transparent protective film is provided on both sides, but the pressure-sensitive adhesive layer is an ionic compound. When the antistatic function is imparted by containing the above, the effect of the ionic compound in the pressure-sensitive adhesive layer on the polarizer is large. For example, when an ionic liquid or an ionic solid is used as the ionic compound. Has a problem that the polarizer is deteriorated and the optical characteristics are significantly deteriorated after the humidification test.

Further, when a layer containing a conductive polymer such as polythiophene is provided on the polarizing plate and the pressure-sensitive adhesive layer as in Patent Document 5, the polarizer is deteriorated and the optical characteristics are deteriorated.

An object of the present invention is to provide an adhesive polarizing plate having an antistatic function, an adhesive layer satisfying durability, and little deterioration of optical characteristics.

Another object of the present invention is to provide an image display device using the adhesive polarizing plate.

As a result of diligent studies to solve the above problems, the present inventors have found the following adhesive polarizing plate and have completed the present invention.

That is, the present invention is a pressure-sensitive polarizing plate having a polarizing plate and a pressure-sensitive adhesive layer provided on the polarizing plate.
The polarizing plate has a transparent protective film on only one side of the polarizing element, the pressure-sensitive adhesive layer is provided on the polarizing element on the side that does not have the transparent protective film, and the pressure-sensitive adhesive layer is (meth. ) A pressure-sensitive polarizing plate, characterized in that it is formed from a pressure-sensitive adhesive composition containing an acrylic polymer (A) and an alkali metal salt (B).

In the adhesive polarizing plate, the alkali metal salt (B) is preferably a lithium salt.

The adhesive polarizing plate preferably contains 0.0001 to 5 parts by weight of the alkali metal salt (B) with respect to 100 parts by weight of the (meth) acrylic polymer (A).

In the above-mentioned adhesive polarizing plate, a polarizing element having a thickness of 10 μm or less can be used. The polarizer having a thickness of 10 μm or less is a continuous web polarizing film made of a polyvinyl alcohol-based resin in which a dichroic substance is oriented, and includes a polyvinyl alcohol-based resin layer formed on a thermoplastic resin base material. It is possible to use a laminate obtained by stretching the laminate in a two-step stretching step consisting of auxiliary stretching in the air and stretching in water with boric acid.

In the adhesive polarizing plate, the (meth) acrylic polymer (A) preferably contains an alkyl (meth) acrylate and a hydroxyl group-containing monomer as a monomer unit.

In the adhesive polarizing plate, as the (meth) acrylic polymer (A), those containing an alkyl (meth) acrylate and a carboxyl group-containing monomer can be preferably used as the monomer unit.

In the pressure-sensitive polarizing plate, the pressure-sensitive adhesive composition can further contain a cross-linking agent. In the pressure-sensitive adhesive composition, the cross-linking agent (C) is preferably contained in an amount of 0.01 to 20 parts by weight with respect to 100 parts by weight of the (meth) acrylic polymer (A). The cross-linking agent (C) is preferably at least one selected from isocyanate compounds and peroxides.

The adhesive polarizing plate may further contain 0.001 to 5 parts by weight of the silane coupling agent (D) with respect to 100 parts by weight of the (meth) acrylic polymer (A).

The adhesive polarizing plate may further contain 0.001 to 10 parts by weight of the polyether-modified silicone compound with respect to 100 parts by weight of the (meth) acrylic polymer (A).

In the adhesive polarizing plate, the weight average molecular weight of the (meth) acrylic polymer (A) is preferably 500,000 to 3,000,000.

The pressure-sensitive polarizing plate may have an easy-adhesion layer between the polarizing plate and the pressure-sensitive adhesive layer.

The present invention also relates to an image display device characterized in that at least one of the adhesive polarizing plates is used.

In a pressure-sensitive adhesive using an acrylic polymer as a base polymer, an antistatic function can be imparted by blending the pressure-sensitive adhesive with an ionic compound. In this case, it is considered that the antistatic function is efficiently exhibited by bleeding out the ionic compound on the surface of the pressure-sensitive adhesive layer. On the other hand, when the ionic compound comes into contact with the polarizer, optical characteristics such as the degree of polarization may deteriorate.

The pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer of the pressure-sensitive polarizing plate of the present invention is an alkali metal salt capable of imparting an antistatic function in addition to the (meth) acrylic polymer (A) which is the base polymer. The pressure-sensitive adhesive layer containing (B) and formed by the pressure-sensitive adhesive composition has an excellent antistatic function. Further, in the present invention, it has been found that the use of the alkali metal salt (B) can impart an antistatic function without causing deterioration of the polarizer.

The pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer of the pressure-sensitive polarizing plate of the present invention contains a (meth) acrylic polymer (A) as a base polymer. The (meth) acrylic polymer (A) usually contains an alkyl (meth) acrylate as a main component as a monomer unit. In addition, (meth) acrylate means acrylate and / or methacrylate, and has the same meaning as (meth) of the present invention.

Examples of the alkyl (meth) acrylate constituting the main skeleton of the (meth) acrylic polymer (A) include linear or branched alkyl groups having 1 to 18 carbon atoms. For example, the alkyl group includes a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, an amyl group, a hexyl group, a cyclohexyl group, a heptyl group, a 2-ethylhexyl group, an isooctyl group, a nonyl group and a decyl group. Examples thereof include a group, an isodecyl group, a dodecyl group, an isomyristyl group, a lauryl group, a tridecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, and the like. These can be used alone or in combination. The average carbon number of these alkyl groups is preferably 3-9.

Further, from the viewpoints of adhesive properties, durability, adjustment of phase difference, adjustment of refractive index, etc., alkyl (meth) acrylates containing an aromatic ring such as phenoxyethyl (meth) acrylate and benzyl (meth) acrylate are used. be able to. The alkyl (meth) acrylate containing an aromatic ring can be used by mixing a polymer obtained by polymerizing the same with the above-exemplified (meth) acrylic polymer, but from the viewpoint of transparency, the alkyl (meth) acrylate contains an aromatic ring. The alkyl (meth) acrylate is preferably used by copolymerizing with the alkyl (meth) acrylate.

The ratio of the alkyl (meth) acrylate containing the aromatic ring in the (meth) acrylic polymer (A) is 50 in the weight ratio of the total constituent monomers (100% by weight) of the (meth) acrylic polymer (A). It can be contained in a proportion of% by weight or less. Further, the content of the alkyl (meth) acrylate containing an aromatic ring is preferably 1 to 35% by weight, more preferably 1 to 20% by weight, further preferably 7 to 18% by weight, and further preferably 10 to 16% by weight. % By weight is preferred.

The (meth) acrylic polymer (A) has a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group for the purpose of improving adhesiveness and heat resistance. One or more types of copolymerization monomers can be introduced by copolymerization. Specific examples of such a copolymerization monomer include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 6 (meth) acrylate. Hydroxyl group-containing monomers such as −hydroxyhexyl, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate and (4-hydroxymethylcyclohexyl) -methylacrylate (Meta) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid and other carboxyl group-containing monomers; Maleic anhydride, itaconic anhydride and other acid anhydrides Group-containing monomer; caprolactone adduct of acrylic acid; styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, ( Meta) Examples thereof include sulfonic acid group-containing monomers such as acryloyloxynaphthalene sulfonic acid; and phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate.

Further, (N-substituted) amides such as (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, and N-methylolpropane (meth) acrylamide. Monomer; (meth) alkylaminoalkyl-acrylate monomer such as aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate; (meth) acrylic (Meta) alkoxyalkyl-based monomers such as methoxyethyl acid and ethoxyethyl (meth) acrylate; N- (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxyhexamethylene succinimide, N-( Meta) Succinimide-based monomers such as acryloyl-8-oxyoctamethylene succinimide and N-acryloylmorpholin; maleimide-based monomers such as N-cyclohexyl maleimide, N-isopropyl maleimide, N-lauryl maleimide and N-phenylmaleimide; Italonimide-based monomers such as imide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, and N-laurylitaconimide are also used for modification. As an example of the monomer of.

Further, as modified monomers, vinyl acetate, vinyl propionate, N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazin, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole, vinylmorpholin, N- Vinyl-based monomers such as vinylcarboxylic acid amides, styrene, α-methylstyrene, N-vinylcaprolactam; cyanoacrylate-based monomers such as acrylonitrile and methacrylonitrile; epoxy group-containing acrylic monomers such as glycidyl (meth) acrylate; Glycol-based acrylic ester monomers such as (meth) polyethylene glycol acrylate, (meth) polypropylene glycol acrylate, (meth) methoxyethylene glycol acrylate, (meth) methoxypolypropylene glycol acrylate; (meth) tetrahydrofurfuryl acrylate, Acrylic acid ester-based monomers such as fluorine (meth) acrylate, silicone (meth) acrylate and 2-methoxyethyl acrylate can also be used. Further, isoprene, butadiene, isobutylene, vinyl ether and the like can be mentioned.

Further, as a copolymerizable monomer other than the above, a silane-based monomer containing a silicon atom and the like can be mentioned. Examples of the silane-based monomer include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, and 8-vinyloctyltrimethoxysilane. , 8-Vinyloctyloxydecyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, 10-acryloyloxydecyltriethoxysilane and the like.

Examples of the copolymerization monomer include tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, and neo. Pentyl glycol di (meth) acrylate, trimethyl propantri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate , Caprolactone-modified dipentaerythritol Hexa (meth) Acrylate and other (meth) acrylic acids and polyhydric alcohols such as esterified products such as (meth) acryloyl groups and vinyl groups and other unsaturated double bonds having two or more unsaturated double bonds. Polyester (meth) acrylates and epoxys (meth) acrylates and epoxys in which two or more unsaturated double bonds such as (meth) acryloyl groups and vinyl groups are added as functional groups similar to the monomer components to the skeletons of sex monomers, polyesters, epoxys, urethanes, etc. Meta) acrylate, urethane (meth) acrylate and the like can also be used.

The (meth) acrylic polymer (A) contains an alkyl (meth) acrylate as a main component in the weight ratio of all the constituent monomers, and the ratio of the copolymerized monomer in the (meth) acrylic polymer (A) is particularly limited. However, the proportion of the copolymerized monomer is preferably about 0 to 20%, about 0.1 to 15%, and more preferably about 0.1 to 10% in terms of the weight ratio of all the constituent monomers.

Among these copolymerizable monomers, a hydroxyl group-containing monomer and a carboxyl group-containing monomer are preferably used from the viewpoint of adhesiveness and durability. A hydroxyl group-containing monomer and a carboxyl group-containing monomer can be used in combination. These copolymerizable monomers serve as reaction points with the cross-linking agent when the pressure-sensitive adhesive composition contains the cross-linking agent. Since the hydroxyl group-containing monomer and the carboxyl group-containing monomer are highly reactive with the intermolecular cross-linking agent, they are preferably used for improving the cohesiveness and heat resistance of the obtained pressure-sensitive adhesive layer. The hydroxyl group-containing monomer is preferable in terms of reworkability, and the carboxyl group-containing monomer is preferable in terms of achieving both durability and reworkability.

When a hydroxyl group-containing monomer is contained as the copolymerization monomer, the proportion thereof is preferably 0.01 to 15% by weight, more preferably 0.03 to 10% by weight, and further preferably 0.05 to 7% by weight. .. When a carboxyl group-containing monomer is contained as the copolymerization monomer, the proportion thereof is preferably 0.05 to 10% by weight, more preferably 0.1 to 8% by weight, and further preferably 0.2 to 6% by weight. ..

As the (meth) acrylic polymer (A) of the present invention, a polymer having a weight average molecular weight in the range of 500,000 to 3,000,000 is usually used. Considering durability, particularly heat resistance, it is preferable to use one having a weight average molecular weight of 700,000 to 2.7 million. Further, it is preferably 800,000 to 2.5 million. If the weight average molecular weight is less than 500,000, it is not preferable in terms of heat resistance. Further, when the weight average molecular weight is larger than 3 million, a large amount of diluting solvent is required to adjust the viscosity for coating, which is not preferable because it increases the cost. The weight average molecular weight is a value measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene.

For the production of such a (meth) acrylic polymer (A), known production methods such as solution polymerization, bulk polymerization, emulsion polymerization, and various radical polymerizations can be appropriately selected. Further, the obtained (meth) acrylic polymer (A) may be any of a random copolymer, a block copolymer, a graft copolymer and the like.

In solution polymerization, for example, ethyl acetate, toluene and the like are used as the polymerization solvent. As a specific example of solution polymerization, the reaction is carried out under an inert gas stream such as nitrogen, a polymerization initiator is added, and usually at about 50 to 70 ° C. under reaction conditions of about 5 to 30 hours.

The polymerization initiator, chain transfer agent, emulsifier and the like used for radical polymerization are not particularly limited and can be appropriately selected and used. The weight average molecular weight of the (meth) acrylic polymer (A) can be controlled by the amount of the polymerization initiator and the chain transfer agent used, and the reaction conditions, and the amount used is appropriately adjusted according to these types. To.

Examples of the polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride, and 2,2'-azobis [2- (5-methyl-2). -Imidazoline-2-yl) propane] dihydrochloride, 2,2'-azobis (2-methylpropionamidine) disulfate, 2,2'-azobis (N, N'-dimethyleneisobutyramidine), 2,2 Azo-based initiators such as'-azobis [N- (2-carboxyethyl) -2-methylpropion amidine] hydrate (manufactured by Wako Pure Chemical Industries, Ltd., VA-057), persulfates such as potassium persulfate and ammonium persulfate. , Di (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-sec-butylperoxydicarbonate, t-butylperoxyneodecanoate, t-hexylper Oxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, di (4) Peroxides such as -methylbenzoyl) peroxide, dibenzoyl peroxide, t-butylperoxyisobutyrate, 1,1-di (t-hexylperoxy) cyclohexane, t-butylhydroperoxide, hydrogen peroxide, etc. Examples thereof include an initiator, a combination of persulfate and sodium hydrogen sulfite, and a redox-based initiator that combines a peroxide and a reducing agent such as a combination of peroxide and sodium ascorbate, but the present invention is limited to these. It's not something.

The polymerization initiator may be used alone or in combination of two or more, but the total content is 0.005 to 1 part by weight with respect to 100 parts by weight of the monomer. It is preferably about 0.02 to 0.5 parts by weight, and more preferably about 0.02 to 0.5 parts by weight.

In addition, in order to produce the (meth) acrylic polymer (A) having the weight average molecular weight by using, for example, 2,2'-azobisisobutyronitrile as the polymerization initiator, the amount of the polymerization initiator used. Is preferably about 0.06 to 0.2 parts by weight, more preferably about 0.08 to 0.175 parts by weight, based on 100 parts by weight of the total amount of the monomer components.

Examples of the chain transfer agent include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglucolate, 2,3-dimercapto-1-propanol and the like. The chain transfer agent may be used alone or in combination of two or more, but the total content is 0.1 part by weight with respect to 100 parts by weight of the total amount of the monomer components. It is below the degree.

Examples of the emulsifier used in the case of emulsifying polymerization include anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzene sulfonate, ammonium polyoxyethylene alkyl ether sulfate, and sodium polyoxyethylene alkyl phenyl ether sulfate, and polyoxy. Examples thereof include nonionic emulsifiers such as ethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, and polyoxyethylene-polyoxypropylene block polymer. These emulsifiers may be used alone or in combination of two or more.

Further, as an emulsifier into which a radically polymerizable functional group such as a propenyl group or an allyl ether group has been introduced as a reactive emulsifier, specifically, for example, Aqualon HS-10, HS-20, KH-10, BC-05. , BC-10, BC-20 (all manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), Adecaria Soap SE10N (manufactured by Asahi Denko Co., Ltd.) and the like. Since the reactive emulsifier is incorporated into the polymer chain after polymerization, it has good water resistance and is preferable. The amount of the emulsifier used is more preferably 0.3 to 5 parts by weight and 0.5 to 1 part by weight from the viewpoint of polymerization stability and mechanical stability with respect to 100 parts by weight of the total amount of the monomer components.

The pressure-sensitive adhesive composition of the present invention contains an alkali metal salt (B) in addition to the (meth) acrylic polymer (A). The alkali metal salt (B) may be used alone or in combination of two or more. As the alkali metal salt (B), organic salts and inorganic salts of alkali metals can be used.

Examples of the alkali metal ion constituting the cation portion of the alkali metal salt (B) include lithium, sodium, and potassium ions. Among these alkali metal ions, lithium ions are preferable.

The anion portion of the alkali metal salt (B) may be composed of an organic substance or an inorganic substance. Examples of the anion portion constituting the organic salt include CH ₃ COO ⁻ , CF ₃ COO ⁻ , CH ₃ SO ₃ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , and (CF ₃ SO ₂ ). ₃ C ⁻ , C ₄ F ₉ SO ₃ ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , C ₃ F ₇ COO ⁻ , (CF ₃ SO ₂ ) (CF ₃ CO) N ⁻ , ⁻ O ₃ S ( ^{_{CF 2) 3 SO 3 -,}} PF 6 -, CO 3 2-, and the like. In particular, the anion portion containing a fluorine atom is preferably used because an ionic compound having good ionic dissociation property can be obtained. The anion portions constituting the inorganic salt include Cl ⁻ , Br ⁻ , I ⁻ , AlCl ₄ ⁻ , Al ₂ Cl ₇ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , NO ₃ ⁻ , AsF ₆ ⁻ , and SbF. ₆ ⁻ , NbF ₆ ⁻ , TaF ₆ −, (CN) ₂ N ⁻ , etc. are used. As the anion portion, (perfluoroalkylsulfonyl) imides such _{as (CF 3} SO ₂ ) ₂ N ⁻ and (C ₂ F ₅ SO ₂ ) ₂ N ⁻ are preferable, and are particularly represented by _{(CF 3} SO ₂ ) ₂ N ^−. (Trifluoromethanesulfonyl) imide is preferred.

Specific examples of the organic salt of the alkali metal include sodium acetate, sodium alginate, sodium lignin sulfonate, sodium toluene sulfonate, LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, and Li (CF ₃ SO _2). ) ₂ N, Li (C ₂ F ₅ SO ₂ ) ₂ N, Li (C ₄ F ₉ SO ₂ ) ₂ N, Li (CF ₃ SO ₂ ) ₃ C, KO ₃ S (CF ₂ ) ₃ SO ₃ K, _{LiO 3 S (CF 2) 3} SO 3 K , and the like, among these _{LiCF 3 SO 3, Li (CF} 3 SO 2) 2 N, Li (C 2 F 5 SO 2) 2 N, Li (C 4 F ₉ SO ₂ ) ₂ N, Li (CF ₃ SO ₂ ) ₃ C and the like are preferable, and Li (CF ₃ SO ₂ ) ₂ N, Li (C ₂ F ₅ SO ₂ ) ₂ N, Li (C ₄ F ₉ SO) ₂₎ fluorine-containing lithium imide salt is more preferred, such as 2 _N, in particular (perfluoroalkyl sulfonyl) imide lithium salts are preferred.

Examples of the inorganic salt of the alkali metal include lithium perchlorate and lithium iodide.

The ratio of the alkali metal salt (B) in the pressure-sensitive adhesive composition of the present invention is preferably 0.001 to 5 parts by weight with respect to 100 parts by weight of the (meth) acrylic polymer (A). If the alkali metal salt (B) is less than 0.001 part by weight, the effect of improving the antistatic performance may not be sufficient. The alkali metal salt (B) is preferably 0.01 part by weight or more, and more preferably 0.1 part by weight or more. On the other hand, if the amount of the alkali metal salt (B) is more than 5 parts by weight, the durability may not be sufficient. The alkali metal salt (B) is preferably 3 parts by weight or less, more preferably 1 part by weight or less. The ratio of the alkali metal salt (B) can be set in a preferable range by adopting the upper limit value or the lower limit value.

Further, the pressure-sensitive adhesive composition of the present invention may contain a cross-linking agent (C). As the cross-linking agent (C), an organic cross-linking agent or a polyfunctional metal chelate can be used. Examples of the organic cross-linking agent include isocyanate-based cross-linking agents, peroxide-based cross-linking agents, epoxy-based cross-linking agents, and imine-based cross-linking agents. A polyfunctional metal chelate is one in which a polyvalent metal is covalently or coordinated to an organic compound. Examples of the polyvalent metal atom include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti and the like. Can be mentioned. Examples of the atom in the organic compound having a covalent bond or a coordination bond include an oxygen atom, and examples of the organic compound include an alkyl ester, an alcohol compound, a carboxylic acid compound, an ether compound, and a ketone compound.

As the cross-linking agent (C), an isocyanate-based cross-linking agent and / or a peroxide-type cross-linking agent is preferable. Examples of the compound related to the isocyanate-based cross-linking agent include isocyanate monomers such as tolylene diisocyanate, chlorphenylene diisocyanate, tetramethylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, and hydrogenated diphenylmethane diisocyanate, and these isocyanate monomers. Examples include isocyanate compounds added with trimetylolpropane and the like, isocyanurates, bullet-type compounds, and urethane prepolymer-type isocyanates which have been subjected to an addition reaction such as polyether polyols, polyester polyols, acrylic polyols, polybutadiene polyols, and polyisoprene polyols. be able to. Particularly preferred is a polyisocyanate compound, which is one selected from the group consisting of hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, and isophorone diisocyanate, or a polyisocyanate compound derived thereto. Here, one selected from the group consisting of hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, and isophorone diisocyanate or a polyisocyanate compound derived thereto includes hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and polyol modification. Hexamethylene diisocyanate, polyol-modified hydrogenated xylylene diisocyanate, trimmer-type hydrogenated xylylene diisocyanate, polyol-modified isophorone diisocyanate and the like are included. The exemplified polyisocyanate compound is particularly preferable because the reaction with the hydroxyl group proceeds rapidly by using the acid and the base contained in the polymer as a catalyst, which contributes to the speed of cross-linking.

As the peroxide, any peroxide that generates radically active species by heating or light irradiation to promote cross-linking of the base polymer of the pressure-sensitive adhesive composition can be appropriately used, but in consideration of workability and stability. It is preferable to use a peroxide having a half-life temperature of 80 ° C. to 160 ° C. for 1 minute, and more preferably to use a peroxide having a half-life temperature of 90 ° C. to 140 ° C.

Examples of the peroxide that can be used include di (2-ethylhexyl) peroxydicarbonate (1 minute half-life temperature: 90.6 ° C.) and di (4-t-butylcyclohexyl) peroxydicarbonate (1). Minute half-life temperature: 92.1 ° C., di-sec-butylperoxydicarbonate (1 minute half-life temperature: 92.4 ° C.), t-butylperoxyneodecanoate (1 minute half-life temperature: 103) .5 ° C.), t-hexyl peroxypivalate (1 minute half-life temperature: 109.1 ° C.), t-butyl peroxypivalate (1 minute half-life temperature: 110.3 ° C.), dilauroyl peroxide (1 minute half-life temperature: 110.3 ° C.) 1 minute half temperature: 116.4 ° C), di-n-octanoyl peroxide (1 minute half temperature: 117.4 ° C), 1,1,3,3-tetramethylbutylperoxy-2-ethyl Hexanoate (1 minute half-life temperature: 124.3 ° C.), di (4-methylbenzoyl) peroxide (1 minute half-life temperature: 128.2 ° C.), dibenzoyl peroxide (1 minute half-life temperature: 130. 0 ° C.), t-Butylperoxyisobutyrate (1 minute half-life temperature: 136.1 ° C.), 1,1-di (t-hexylperoxy) cyclohexane (1 minute half-life temperature: 149.2 ° C.) And so on. Among them, di (4-t-butylcyclohexyl) peroxydicarbonate (1 minute half-life temperature: 92.1 ° C.) and dilauroyl peroxide (1 minute half-life temperature: 116.) Since the cross-linking reaction efficiency is particularly excellent. 4 ° C.), dibenzoylperoxide (1 minute half-life temperature: 130.0 ° C.) and the like are preferably used.

The half-life of peroxide is an index showing the decomposition rate of peroxide, and means the time until the residual amount of peroxide is halved. The decomposition temperature for obtaining a half-life at an arbitrary time and the half-life time at an arbitrary temperature are described in the manufacturer's catalog, etc. For example, "Organic peroxide catalog 9th edition" of Nippon Oil & Fats Co., Ltd. (May 2003) ”and so on.

The amount of the cross-linking agent (C) used is preferably 0.01 to 20 parts by weight, more preferably 0.03 to 10 parts by weight, based on 100 parts by weight of the (meth) acrylic polymer (A). If the amount of the cross-linking agent (C) is less than 0.01 parts by weight, the cohesive force of the adhesive tends to be insufficient and foaming may occur during heating. On the other hand, if it is more than 20 parts by weight, the moisture resistance is sufficient. Rather, peeling is likely to occur in reliability tests and the like.

The isocyanate-based cross-linking agent may be used alone or in combination of two or more, but the content as a whole is the (meth) acrylic polymer (A) 100. The polyisocyanate compound cross-linking agent is preferably contained in an amount of 0.01 to 2 parts by weight, more preferably 0.02 to 2 parts by weight, and 0.05 to 1.5 parts by weight. It is more preferably contained in parts by weight. It can be appropriately contained in consideration of cohesive force, prevention of peeling in durability test, and the like.

One type of the peroxide may be used alone, or two or more types may be mixed and used, but the content as a whole is 100 weight by weight of the (meth) acrylic polymer (A). The amount of the peroxide is 0.01 to 2 parts by weight, preferably 0.04 to 1.5 parts by weight, and more preferably 0.05 to 1 part by weight. .. It is appropriately selected within this range in order to adjust workability, reworkability, crosslink stability, peelability and the like.

As a method for measuring the amount of peroxide decomposition remaining after the reaction treatment, for example, HPLC (high performance liquid chromatography) can be used.

More specifically, for example, about 0.2 g of the pressure-sensitive adhesive composition after the reaction treatment is taken out, immersed in 10 ml of ethyl acetate, extracted by shaking at 120 rpm for 3 hours at 25 ° C. with a shaker, and then at room temperature. Let stand for 3 days. Next, 10 ml of acetonitrile was added, and the mixture was shaken at 120 rpm at 25 ° C. for 30 minutes, and about 10 μl of the extract obtained by filtering with a membrane filter (0.45 μm) was injected into HPLC for analysis. It can be the amount of peroxide.

Further, the pressure-sensitive adhesive composition of the present invention may contain a silane coupling agent (D). Durability can be improved by using the silane coupling agent (D). Specific examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2- (3,). 4-Epoxycyclohexyl) Epoxy group-containing silane coupling agent such as ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl- Amino group-containing silane coupling agents such as N- (1,3-dimethylbutylidene) propylamine and N-phenyl-γ-aminopropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltri. Examples thereof include a (meth) acrylic group-containing silane coupling agent such as ethoxysilane, and an isocyanate group-containing silane coupling agent such as 3-isocyanatepropyltriethoxysilane.

The silane coupling agent (D) may be used alone or in combination of two or more, but the content as a whole is the (meth) acrylic polymer (A) 100. The silane coupling agent is preferably 0.001 to 5 parts by weight, more preferably 0.01 to 1 part by weight, still more preferably 0.02 to 1 part by weight, and further 0.05 by weight, based on parts by weight. ~ 0.6 parts by weight is preferable. This is an amount that improves durability and appropriately retains the adhesive force to optical members such as liquid crystal cells.

Further, the pressure-sensitive adhesive composition of the present invention may contain a polyether-modified silicone compound. As the polyether-modified silicone compound, for example, those disclosed in JP-A-2010-275522 can be used.

The polyether-modified silicone compound has a polyether skeleton and has at least one terminal at the following general formula (1): -SiR _a M _3-a.
(In the formula, R is a monovalent organic group having 1 to 20 carbon atoms which may have a substituent, M is a hydroxyl group or a hydrolyzable group, and a is an integer of 1 to 3. However, when there are a plurality of Rs, the plurality of Rs may be the same or different from each other, and when there are a plurality of Ms, the plurality of Ms may be the same or different from each other.) It has a reactive silyl group represented.

The polyether-modified silicone compound includes
General formula (2): R _a M _3-a Si-XY- (AO) _n- Z
(In the formula, R is a monovalent organic group having 1 to 20 carbon atoms which may have a substituent, M is a hydroxyl group or a hydrolyzable group, and a is an integer of 1 to 3. However, when there are a plurality of Rs, the plurality of Rs may be the same or different from each other, and when there are a plurality of Ms, the plurality of Ms may be the same or different from each other. , A linear or branched oxyalkylene group having 1 to 10 carbon atoms, n being 1 to 1700, indicating the average number of moles of the oxyalkylene group added. X is a linear or branched chain having 1 to 20 carbon atoms. The alkylene group of the branched chain is shown. Y represents an ether bond, an ester bond, a urethane bond, or a carbonate bond.
Z is a hydrogen atom, a hydrocarbon group having 1 to 10 monovalent carbon atoms,
General formula (2A): -Y _1- X-SiR _a M _3-a
(In the equation, R, M, X are the same as above. Y ¹ indicates a single bond, -CO- bond, -CONH- bond, or -COO- bond.) Or.
General formula (2B): -Q {-(OA) _n- Y-X-SiR _a M _3-a } _m
(In the formula, R, M, X, Y are the same as above. OA is the same as AO, n is the same as above. Q is a hydrocarbon group having 2 or more valences and having 1 to 10 carbon atoms. , M is the same as the valence of the hydrocarbon group). ) Is mentioned.

Specific examples of the polyether-modified silicone compound include MS polymers S203, S303, S810 manufactured by Kaneka Corporation; SILYL EST250, EST280; SAT10, SAT200, SAT220, SAT350, SAT400, EXCESTARS2410, S2420 or S3430 manufactured by Asahi Glass Co., Ltd. Can be mentioned.

Further, the pressure-sensitive adhesive composition of the present invention may contain other known additives, for example, a polyether compound of a polyalkylene glycol such as polypropylene glycol, a colorant, a powder such as a pigment, a dye, and the like. Surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, antioxidants, light stabilizers, UV absorbers, polymerization inhibitors, inorganic or organic fillers, metals It can be appropriately added depending on the intended use of powder, particulate, foil or the like. Further, a redox system to which a reducing agent is added may be adopted within a controllable range.

A pressure-sensitive adhesive layer is formed by the pressure-sensitive adhesive composition. In forming the pressure-sensitive adhesive layer, it is necessary to adjust the amount of the entire cross-linking agent added and to fully consider the effects of the cross-linking treatment temperature and the cross-linking treatment time. preferable.

The cross-linking treatment temperature and the cross-linking treatment time can be adjusted depending on the cross-linking agent used. The crosslinking treatment temperature is preferably 170 ° C. or lower.

Further, the cross-linking treatment may be performed at the temperature at the time of the drying step of the pressure-sensitive adhesive layer, or a separate cross-linking treatment step may be provided after the drying step.

The cross-linking treatment time can be set in consideration of productivity and workability, but is usually about 0.2 to 20 minutes, preferably about 0.5 to 10 minutes.

In the pressure-sensitive polarizing plate of the present invention, a transparent protective film is provided only on one side of the polarizing element, and a pressure-sensitive adhesive layer is formed on the polarizing element by the pressure-sensitive adhesive composition without providing a transparent protective film on the other side. It is a thing.

As a method of forming the pressure-sensitive adhesive layer, for example, a method of applying the pressure-sensitive adhesive composition to a separator or the like which has been peeled off, drying and removing a polymerization solvent or the like to form a pressure-sensitive adhesive layer, and then transferring the pressure-sensitive adhesive layer to a polarizing plate, or a method of transferring to a polarizing plate. It is produced by a method of applying the pressure-sensitive adhesive composition to a polarizing plate and drying and removing a polymerization solvent or the like to form a pressure-sensitive adhesive layer on the polarizing plate. When applying the pressure-sensitive adhesive, one or more solvents other than the polymerization solvent may be newly added as appropriate.

A silicone release liner is preferably used as the release-treated separator. In the step of applying the adhesive composition of the present invention on such a liner and drying it to form an adhesive layer, as a method of drying the adhesive, an appropriate method is appropriately adopted depending on the purpose. obtain. Preferably, a method of overheating and drying the coating film is used. The heating and drying temperature is preferably 40 ° C. to 200 ° C., more preferably 50 ° C. to 180 ° C., and particularly preferably 70 ° C. to 170 ° C. By setting the heating temperature in the above range, a pressure-sensitive adhesive having excellent adhesive properties can be obtained.

As the drying time, an appropriate time can be adopted as appropriate. The drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 10 minutes, and particularly preferably 10 seconds to 5 minutes.

Further, an anchor layer can be formed on the surface of the polarizing plate, or an adhesive layer can be formed after various easy-adhesion treatments such as corona treatment and plasma treatment are performed. Further, the surface of the pressure-sensitive adhesive layer may be subjected to an easy-adhesion treatment.

Various methods are used as a method for forming the pressure-sensitive adhesive layer. Specifically, for example, roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, die coater, etc. Examples include a method such as an extrusion coating method.

The thickness of the pressure-sensitive adhesive layer is not particularly limited, and is, for example, about 1 to 100 μm. It is preferably 2 to 50 μm, more preferably 2 to 40 μm, and even more preferably 5 to 35 μm.

When the pressure-sensitive adhesive layer is exposed, the pressure-sensitive adhesive layer may be protected by a sheet (separator) that has been peeled off until it is put into practical use.

Examples of the constituent material of the separator include plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester film, porous materials such as paper, cloth, and non-woven fabric, nets, foam sheets, metal foils, and laminates thereof. A thin leaf body or the like can be mentioned, but a plastic film is preferably used because of its excellent surface smoothness.

The plastic film is not particularly limited as long as it can protect the pressure-sensitive adhesive layer, and for example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, and vinyl chloride are all used. Examples thereof include a polymer film, a polyethylene terephthalate film, a polybutylene terephthalate film, a polyurethane film, and an ethylene-vinyl acetate copolymer film.

The thickness of the separator is usually about 5 to 200 μm, preferably about 5 to 100 μm. If necessary, the separator may be used for mold release and antifouling treatment with a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based mold release agent, silica powder, etc., as well as a coating type, a kneading type, and a vapor deposition type. It is also possible to perform antistatic treatment such as. In particular, the peelability from the pressure-sensitive adhesive layer can be further enhanced by appropriately performing a peeling treatment such as a silicone treatment, a long-chain alkyl treatment, or a fluorine treatment on the surface of the separator.

The peeled sheet used for producing the above-mentioned adhesive polarizing plate can be used as it is as a separator for the adhesive polarizing plate, and the process can be simplified.

As the polarizing plate, a polarizing plate having a transparent protective film on only one side of the polarizer is used.

The polarizer is not particularly limited, and various polarizers can be used. Examples of the polarizer include a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, and an ethylene-vinyl acetate copolymerization system partially saponified film, and a bicolor property of iodine or a bicolor dye. Examples thereof include a uniaxially stretched film obtained by adsorbing a substance, a polyene-based oriented film such as a dehydrated product of polyvinyl alcohol and a dehydrogenated product of polyvinyl chloride. Among these, a polarizer made of a polyvinyl alcohol-based film and a dichroic substance such as iodine is preferable. The thickness of these polarizers is not particularly limited, but is generally about 80 μm or less.

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

Further, as the polarizer, a thin polarizer having a thickness of 10 μm or less can be used. From the viewpoint of thinning, the thickness is preferably 1 to 7 μm. It is preferable that such a thin polarizing element has less uneven thickness, excellent visibility, excellent durability because there is little dimensional change, and the thickness of the polarizing plate can be reduced.

Typical examples of the thin polarizing element include JP-A-51-069644, JP-A-2000-338329, WO2010 / 100917 pamphlet, PCT / JP2010 / 00146, or Japanese Patent Application No. 2010-. Examples thereof include the thin polarizing film described in the specification of No. 269002 and the specification of Japanese Patent Application No. 2010-263692. These thin polarizing films can be obtained by a manufacturing method including a step of stretching a polyvinyl alcohol-based resin (hereinafter, also referred to as PVA-based resin) layer and a resin base material for stretching in a laminated state and a step of dyeing. With this manufacturing method, even if the PVA-based resin layer is thin, it can be stretched without problems such as breakage due to stretching because it is supported by the stretching resin base material.

Among the manufacturing methods including a step of stretching in a laminated state and a step of dyeing, the thin polarizing film can be stretched at a high magnification and the polarization performance can be improved. It is preferably obtained by a production method including a step of stretching in an aqueous boric acid solution as described in JP2010 / 00460, or in Japanese Patent Application No. 2010-269002 and Japanese Patent Application No. 2010-263692, particularly preferably. It is preferably obtained by a production method including a step of auxiliary stretching in the air before stretching in an aqueous boric acid solution described in Japanese Patent Application No. 2010-269002 and Japanese Patent Application No. 2010-263692.

The thin and high-performance polarizing film described in the above description of PCT / JP2010 / 00160 is a thin thin film having a thickness of 7 μm or less made of a PVA-based resin in which a dichroic substance is oriented, which is integrally formed on a resin substrate. It is a high-performance polarizing film and has optical characteristics such as a single transmittance of 42.0% or more and a degree of polarization of 99.95% or more.

In the thin high-performance polarizing film, a PVA-based resin layer is formed by applying and drying a PVA-based resin on a resin base material having a thickness of at least 20 μm, and the generated PVA-based resin layer is used as a dyeing solution for a bicolor substance. The PVA-based resin layer on which the bicolorous substance is adsorbed is adsorbed on the PVA-based resin layer by immersing the PVA-based resin layer in the boric acid aqueous solution, and the total draw ratio is increased integrally with the resin base material. It can be produced by stretching it so as to be 5 times or more of.

Further, it is a method for producing a laminated film containing a thin and highly functional polarizing film in which a bicolor substance is oriented, and contains a resin base material having a thickness of at least 20 μm and a PVA-based resin on one side of the resin base material. The laminate containing a step of producing a laminate film containing a PVA-based resin layer formed by applying and drying an aqueous solution, and a PVA-based resin layer formed on one side of the resin base material and the resin base material. A step of adsorbing a bicolor substance on a PVA-based resin layer contained in a laminated film by immersing the film in a dyeing solution containing a bicolor substance, and a PVA-based resin adsorbing the bicolor substance. The step of stretching the laminated film containing the layer so that the total draw ratio is 5 times or more of the original length in the boric acid aqueous solution, and the PVA-based resin layer on which the bicolor substance is adsorbed are the resin base material. The thickness is 7 μm or less, the single permeability is 42.0% or more, and the degree of polarization is 99, which is composed of a PVA-based resin layer in which a bicolor substance is oriented on one side of the resin base material. The thin and highly functional polarizing film can be produced by including the step of producing a laminated film obtained by forming a thin and highly functional polarizing film having an optical characteristic of .95% or more.

In the present invention, as described above, the pressure-sensitive polarizing plate is a continuous web polarizing film made of a PVA-based resin in which a dichroic substance is oriented as a polarizer having a thickness of 10 μm or less, and is a thermoplastic resin. A laminate obtained by stretching a laminate containing a polyvinyl alcohol-based resin layer formed on a substrate in a two-step stretching step consisting of auxiliary stretching in the air and stretching in water with boric acid can be used. As the thermoplastic resin base material, an amorphous ester-based thermoplastic resin base material or a crystalline ester-based thermoplastic resin base material is preferable.

The thin polarizing film of Japanese Patent Application No. 2010-269002 and Japanese Patent Application No. 2010-263692 is a continuous web polarizing film made of a PVA-based resin in which a dichroic substance is oriented, and is amorphous. The laminate containing the PVA-based resin layer formed on the ester-based thermoplastic resin base material was stretched in a two-step stretching step consisting of aerial auxiliary stretching and boric acid water stretching to obtain a thickness of 10 μm or less. It is a thing. In such a thin polarizing film, when the simple substance transmittance is T and the degree of polarization is P, P> − (10 ^{0.929 T-42.4-1} ) × 100 (where T <42.3), and P ≧ It is preferable that the material has optical characteristics that satisfy the condition of 99.9 (however, T ≧ 42.3).

Specifically, the thin polarizing film is a stretching intermediate composed of a PVA-based resin layer oriented by high-temperature stretching in the air with respect to a PVA-based resin layer formed on a continuous web amorphous ester-based thermoplastic resin base material. Colored intermediate formation consisting of a PVA-based resin layer in which a dichroic substance (preferably iodine or a mixture of iodine and an organic dye) is oriented by a step of producing a product and adsorption of the dichroic substance to the stretching intermediate product. A thin polarizing film including a step of forming a substance and a step of forming a polarizing film having a thickness of 10 μm or less composed of a PVA-based resin layer in which a dichroic substance is oriented by stretching in boric acid with respect to a colored intermediate product. It can be manufactured by the manufacturing method of.

In this production method, the total draw ratio of the PVA-based resin layer formed on the amorphous ester-based thermoplastic resin base material by high-temperature stretching in the air and stretching in water boric acid is set to 5 times or more. desirable. The liquid temperature of the boric acid aqueous solution for stretching in boric acid water can be 60 ° C. or higher. Before stretching the colored intermediate product in the boric acid aqueous solution, it is desirable to insolubilize the colored intermediate product. In that case, the colored intermediate product is added to the boric acid aqueous solution whose liquid temperature does not exceed 40 ° C. It is desirable to do this by immersing. The amorphous ester-based thermoplastic resin base material is an amorphous polyethylene containing copolymerized polyethylene terephthalate copolymerized with isophthalic acid, copolymerized polyethylene terephthalate copolymerized with cyclohexanedimethanol, or other copolymerized polyethylene terephthalate. It can be made of terephthalate, preferably made of a transparent resin, and its thickness can be 7 times or more the thickness of the PVA-based resin layer to be formed. The stretching ratio of the high-temperature stretching in the air is preferably 3.5 times or less, and the stretching temperature of the high-temperature stretching in the air is preferably equal to or higher than the glass transition temperature of the PVA-based resin, specifically in the range of 95 ° C to 150 ° C. When high-temperature stretching in the air is performed by free-end uniaxial stretching, the total stretching ratio of the PVA-based resin layer formed on the amorphous ester-based thermoplastic resin base material is preferably 5 times or more and 7.5 times or less. .. Further, when high-temperature stretching in the air is performed by uniaxial stretching at a fixed end, the total stretching ratio of the PVA-based resin layer formed on the amorphous ester-based thermoplastic resin base material is 5 times or more and 8.5 times or less. Is preferable.
More specifically, a thin polarizing film can be manufactured by the following method.

A continuous web substrate of isophthalic acid copolymerized polyethylene terephthalate (amorphous PET) obtained by copolymerizing 6 mol% of isophthalic acid is prepared. The glass transition temperature of amorphous PET is 75 ° C. A laminate composed of an amorphous PET substrate of a continuous web and a polyvinyl alcohol (PVA) layer is prepared as follows. Incidentally, the glass transition temperature of PVA is 80 ° C.

An amorphous PET substrate having a thickness of 200 μm and a PVA aqueous solution having a degree of polymerization of 1000 or more and a PVA powder having a degree of polymerization of 99% or more dissolved in water and having a concentration of 4 to 5% are prepared. Next, a PVA aqueous solution is applied to a 200 μm-thick amorphous PET base material and dried at a temperature of 50 to 60 ° C. to obtain a laminate in which a 7 μm-thick PVA layer is formed on the amorphous PET base material. ..

A thin, high-performance polarizing film having a thickness of 3 μm is produced from a laminate containing a PVA layer having a thickness of 7 μm through the following steps including a two-step stretching step of auxiliary stretching in the air and stretching in boric acid in water. By the first-stage aerial auxiliary stretching step, the laminated body containing the PVA layer having a thickness of 7 μm is stretched integrally with the amorphous PET substrate to produce a stretched laminated body containing the PVA layer having a thickness of 5 μm. Specifically, this stretched laminate is subjected to a stretching device equipped in an oven set to a stretching temperature environment of 130 ° C. to obtain a stretching ratio of 1.8 times by subjecting the laminated body containing a 7 μm-thick PVA layer to a stretching device. It is stretched uniaxially at the free end. By this stretching treatment, the PVA layer contained in the stretched laminate is changed into a 5 μm-thick PVA layer in which PVA molecules are oriented.

Next, the dyeing step produces a colored laminate in which iodine is adsorbed on a 5 μm-thick PVA layer in which PVA molecules are oriented. Specifically, in this colored laminate, the stretched laminate is mixed with a dyeing solution containing iodine and potassium iodide at a liquid temperature of 30 ° C., and the single transmittance of the PVA layer constituting the high-performance polarizing film finally produced is obtained. Iodine was adsorbed on the PVA layer contained in the stretched laminate by immersing it for an arbitrary time so that the amount of iodine was 40 to 44%. In this step, the dyeing solution uses water as a solvent and has an iodine concentration in the range of 0.12 to 0.30% by weight and a potassium iodide concentration in the range of 0.7 to 2.1% by weight. The ratio of iodine to potassium iodide concentrations is 1: 7. By the way, potassium iodide is required to dissolve iodine in water. More specifically, by immersing the stretched laminate in a dyeing solution having an iodine concentration of 0.30% by weight and a potassium iodide concentration of 2.1% by weight for 60 seconds, iodine was added to a 5 μm-thick PVA layer in which PVA molecules were oriented. To produce a colored laminate in which iodine is adsorbed.

Further, by the second step of stretching in boric acid in water, the colored laminate is further stretched integrally with the amorphous PET substrate to generate an optical film laminate containing a PVA layer constituting a high-performance polarizing film having a thickness of 3 μm. To do. Specifically, this optical film laminate is stretched by subjecting the colored laminate to a stretching device installed in a processing device set in a boric acid aqueous solution having a liquid temperature range of 60 to 85 ° C. containing boric acid and potassium iodide. It is stretched uniaxially at the free end so that the magnification is 3.3 times. More specifically, the liquid temperature of the boric acid aqueous solution is 65 ° C. It also has a boric acid content of 4 parts by weight with respect to 100 parts by weight of water and a potassium iodide content of 5 parts by weight with respect to 100 parts by weight of water. In this step, the colored laminate having an adjusted iodine adsorption amount is first immersed in a boric acid aqueous solution for 5 to 10 seconds. After that, the colored laminate is passed as it is between a plurality of sets of rolls having different peripheral speeds, which is a stretching device deployed in the processing device, and the stretching ratio is freely increased to 3.3 times over 30 to 90 seconds. Stretch uniaxially. By this stretching treatment, the PVA layer contained in the colored laminate is changed into a 3 μm-thick PVA layer in which the adsorbed iodine is highly oriented in one direction as a polyiodine ion complex. This PVA layer constitutes a high-performance polarizing film of an optical film laminate.

Although not an essential step in the production of the optical film laminate, the optical film laminate was taken out from the boric acid aqueous solution by the cleaning step and adhered to the surface of the 3 μm-thick PVA layer formed on the amorphous PET substrate. It is preferable to wash boric acid with an aqueous solution of potassium iodide. After that, the washed optical film laminate is dried by a drying step with warm air at 60 ° C. The cleaning step is a step for eliminating appearance defects such as boric acid precipitation.

Similarly, although it is not an essential step for producing an optical film laminate, an adhesive is applied to the surface of a 3 μm-thick PVA layer formed on an amorphous PET substrate by a bonding and / or transfer step. However, after the 80 μm-thick triacetyl cellulose film is attached, the amorphous PET substrate can be peeled off and the 3 μm-thick PVA layer can be transferred to the 80 μm-thick triacetyl cellulose film.

[Other processes]
The method for producing a thin polarizing film may include other steps in addition to the above steps. Examples of other steps include an insolubilization step, a cross-linking step, a drying (adjustment of water content) step, and the like. Other steps can be performed at any suitable timing.
The insolubilization step is typically performed by immersing a PVA-based resin layer in an aqueous boric acid solution. By applying the insolubilization treatment, water resistance can be imparted to the PVA-based resin layer. The concentration of the boric acid aqueous solution is preferably 1 part by weight to 4 parts by weight with respect to 100 parts by weight of water. The liquid temperature of the insolubilizing bath (boric acid aqueous solution) is preferably 20 ° C. to 50 ° C. Preferably, the insolubilization step is performed after the laminate is prepared and before the dyeing step and the underwater stretching step.
The cross-linking step is typically performed by immersing a PVA-based resin layer in an aqueous boric acid solution. Water resistance can be imparted to the PVA-based resin layer by subjecting it to a cross-linking treatment. The concentration of the boric acid aqueous solution is preferably 1 part by weight to 4 parts by weight with respect to 100 parts by weight of water. Further, when the cross-linking step is performed after the dyeing step, it is preferable to further add iodide. By blending iodide, the elution of iodine adsorbed on the PVA-based resin layer can be suppressed. The blending amount of iodide is preferably 1 part by weight to 5 parts by weight with respect to 100 parts by weight of water. Specific examples of iodide are as described above. The liquid temperature of the crosslinked bath (boric acid aqueous solution) is preferably 20 ° C. to 50 ° C. Preferably, the cross-linking step is performed before the second boric acid water stretching step. In a preferred embodiment, the dyeing step, the cross-linking step, and the second boric acid water stretching step are performed in this order.

As a material constituting the transparent protective film, for example, a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture barrier property, isotropic property, etc. is used. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose, polyester resins, polyether sulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) acrylic resins, and cyclic resins. Examples thereof include polyolefin resins (norbornene-based resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. The transparent protective film may contain one or more of any suitable additives. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a mold release agent, an antioxidant, a flame retardant, a nucleating agent, an antistatic agent, a pigment, a coloring agent and the like. 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 the content of the thermoplastic resin in the transparent protective film is 50% by weight or less, the high transparency inherent in the thermoplastic resin may not be sufficiently exhibited.

A transparent protective film is attached to one side of the polarizer by an adhesive layer. An adhesive is used for the bonding process between the polarizer and the transparent protective film. Examples of the adhesive include isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl-based latex-based adhesives, and water-based polyesters. The adhesive is usually used as an adhesive consisting of an aqueous solution, and usually contains 0.5 to 60% by weight of a solid content. In addition to the above, examples of the adhesive between the polarizer and the transparent protective film include an ultraviolet curable adhesive and an electron beam curable adhesive. The adhesive for an electron beam-curable polarizing plate exhibits suitable adhesiveness to the above-mentioned various transparent protective films. Further, the adhesive used in the present invention may contain a metal compound filler.

Further, the polarizing plate can be laminated with another optical film. Other optical films include, for example, for forming liquid crystal display devices such as reflectors, antitransparent plates, retardation plates (including wave plates such as 1/2 and 1/4), visual compensation films, and luminance improving films. Examples include those that are optical layers that may be used. These can be laminated on the polarizing plate in practical use and used as one layer or two or more layers.

An optical film in which the optical layer is laminated on a polarizing plate can also be formed by a method in which the optical film is sequentially and separately laminated in the manufacturing process of a liquid crystal display device or the like. It is excellent in stability and assembly work, and has an advantage that the manufacturing process of a liquid crystal display device or the like can be improved. An appropriate adhesive means such as an adhesive layer can be used for laminating. When the above-mentioned polarizing plate is bonded to another optical layer, their optical axes can be arranged at an appropriate arrangement angle according to a target phase difference characteristic or the like.

The adhesive polarizing plate of the present invention can be preferably used for forming various image display devices such as a liquid crystal display device. The liquid crystal display device can be formed in the same manner as before. That is, the liquid crystal display device is generally formed by appropriately assembling a display panel such as a liquid crystal cell, an adhesive polarizing plate, and if necessary, components such as a lighting system, and incorporating a drive circuit. In the above, there is no particular limitation except that the adhesive polarizing plate according to the present invention is used, and the conventional method can be applied. As the liquid crystal cell, any type such as TN type, STN type, π type, VA type, IPS type and the like can be used.

It is possible to form an appropriate liquid crystal display device such as a liquid crystal display device in which adhesive polarizing plates are arranged on one side or both sides of a display panel such as a liquid crystal cell, or a lighting system using a backlight or a reflector. In that case, the adhesive polarizing plate according to the present invention can be installed on one side or both sides of a display panel such as a liquid crystal cell. When the optical films are provided on both sides, they may be the same or different. Further, when forming the liquid crystal display device, for example, an appropriate component such as a diffuser plate, an anti-glare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffuser plate, and a backlight is placed in one layer or at an appropriate position. Two or more layers can be arranged.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. In addition, each part and% in each example is based on weight. All the conditions left at room temperature, which are not specified below, are 23 ° C. and 65% RH.

<Measurement of weight average molecular weight of (meth) acrylic polymer (A)>
The weight average molecular weight of the (meth) acrylic polymer (A) was measured by GPC (gel permeation chromatography).
-Analyzer: HLC-8120GPC manufactured by Tosoh Corporation
-Column: Made by Tosoh, G7000H _XL + GMH _XL + GMH _XL
-Column size: 7.8 mm φ x 30 cm each 90 cm in total
-Column temperature: 40 ° C
・ Flow rate: 0.8 ml / min
・ Injection amount: 100 μl
・ Eluent: Tetrahydrofuran ・ Detector: Differential refractometer (RI)
・ Standard sample: Polystyrene

<Creation of polarizing plate (1)>
In order to produce a thin polarizing film, first, a laminated body in which a 9 μm-thick PVA layer is formed on an amorphous PET substrate is subjected to aerial auxiliary stretching at a stretching temperature of 130 ° C. to produce a stretched laminated body, and then stretching. A colored laminate is produced by dyeing the laminate, and the colored laminate is further stretched integrally with the amorphous PET substrate by stretching in boric acid at a stretching temperature of 65 ° C so that the total stretching ratio becomes 5.94 times. An optical film laminate containing a PVA layer having a thickness of 4 μm was produced. The PVA molecules in the PVA layer formed on the amorphous PET substrate by such two-step stretching are highly oriented, and the iodine adsorbed by dyeing is highly oriented in one direction as a polyiodine ion complex. It was possible to produce an optical film laminate containing a PVA layer having a thickness of 4 μm, which constitutes a high-performance polarizing film. Further, while applying a polyvinyl alcohol-based adhesive to the surface of the polarizing film of the optical film laminate, a saponified 40 μm-thick triacetyl cellulose film is attached, and then the amorphous PET base material is peeled off. A polarizing plate using a thin polarizing film was produced. Hereinafter, this is referred to as a thin polarizing plate (1).

<Creation of polarizing plate (2)>
A polyvinyl alcohol film having a thickness of 80 μm was dyed between rolls having different speed ratios in an iodine solution at 30 ° C. and a concentration of 0.3% for 1 minute, and stretched up to 3 times. Then, the total stretching ratio was stretched to 6 times while being immersed in an aqueous solution containing boric acid having a concentration of 4% and potassium iodide having a concentration of 10% at 60 ° C. for 0.5 minutes. Then, it was washed by immersing it in an aqueous solution containing potassium iodide having a concentration of 1.5% at 30 ° C. for 10 seconds, and then dried at 50 ° C. for 4 minutes to obtain a polarizer having a thickness of 20 μm. On one surface of the polarizer, a triacetyl cellulose film having a thickness of 40μm was saponified to prepare a polarizing plate bonded by polyvinyl alcohol-based adhesive. Hereinafter, this is referred to as a TAC-based polarizing plate (2).

Manufacturing example 1
<Preparation of acrylic polymer (A1)>
A four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler was charged with a monomer mixture containing 82 parts of butyl acrylate, 15 parts of benzyl acrylate, and 3 parts of 4-hydroxybutyl acrylate. Further, 0.1 part of 2,2'-azobisisobutyronitrile was charged together with ethyl acetate as a polymerization initiator with respect to 100 parts of the monomer mixture (solid content), and nitrogen gas was introduced while gently stirring. After the nitrogen substitution, the liquid temperature in the flask was maintained at around 60 ° C. and the polymerization reaction was carried out for 7 hours. Then, ethyl acetate was added to the obtained reaction solution to prepare a solution of an acrylic polymer (A-1) having a weight average molecular weight of 1 million adjusted to a solid content concentration of 30%.

Manufacturing example 2
<Preparation of acrylic polymer (A-2)>
In Production Example 1, a monomer mixture containing 76.8 parts of butyl acrylate, 10 parts of benzyl acrylate, 10 parts of phenoxyethyl acrylate, 3 parts of 4-hydroxybutyl acrylate and 0.2 part of acrylic acid was used as the monomer mixture. A solution of an acrylic polymer (A2) having a weight average molecular weight of 1 million was prepared in the same manner as in Production Example 1.

Manufacturing example 3
<Preparation of acrylic polymer (A-3)>
Production Example 1 except that a monomer mixture containing 81.9 parts of butyl acrylate, 13 parts of benzyl acrylate, 0.1 part of 2-hydroxyethyl acrylate and 5 parts of acrylic acid was used as the monomer mixture in Production Example 1. In the same manner as above, a solution of an acrylic polymer (A2) having a weight average molecular weight of 1 million was prepared.

Example 1
(Preparation of adhesive composition)
To 100 parts of the solid content of the acrylic polymer (A-1) solution obtained in Production Example 1, 0.002 part of lithium bis (trifluoromethanesulfonyl) imide (manufactured by Nippon Carlit) was added, and further, tri Polymer propanoxylylene diisocyanate (manufactured by Mitsui Chemicals Co., Ltd .: Takenate D110N) 0.1 part, dibenzoyl peroxide 0.3 parts, and γ-glycidoxypropylmethoxysilane (manufactured by Shinetsu Chemical Industry Co., Ltd .: KBM-403) 0 .075 parts were blended to prepare an acrylic pressure-sensitive adhesive solution.

(Manufacturing of adhesive polarizing plate)
Next, the acrylic pressure-sensitive adhesive solution was uniformly applied to the surface of a polyethylene terephthalate film (separator film) treated with a silicone-based release agent with a fountain coater, and dried in an air circulation type constant temperature oven at 155 ° C. for 2 minutes. Then, a pressure-sensitive adhesive layer having a thickness of 20 μm was formed on the surface of the separator film. Next, the pressure-sensitive adhesive layer formed on the separator film was transferred to the side of the polarizing film of the polarizer of the thin polarizing plate (1) prepared above to prepare a pressure-sensitive polarizing plate.

Examples 2 to 17, Comparative Examples 1 to 4
In Example 1, the amount of each component used was changed as shown in Table 1 when preparing the pressure-sensitive adhesive composition, and the type of polarizing plate was changed as shown in Table 1 when producing the pressure-sensitive polarizing plate. An adhesive polarizing plate was produced in the same manner as in Example 1 except for the above.

The following evaluations were performed on the adhesive polarizing plates obtained in the above Examples and Comparative Examples. The evaluation results are shown in Table 1.

<Surface resistance value: initial>
After peeling off the separator film of the adhesive polarizing plate, the surface resistance value (Ω / □) of the adhesive surface was measured using MCP-HT450 manufactured by Mitsubishi Chemical Analytech.

<Evaluation of static electricity unevenness>
The produced adhesive polarizing plate was cut into a size of 100 mm × 100 mm and attached to a liquid crystal panel. This panel was placed on a backlight having a brightness of 10000 cd, and the orientation of the liquid crystal was disturbed by generating static electricity of 5 kv using an ESD generator (ESD-8012A manufactured by SANKI). The recovery time (seconds) of the display defect due to the misalignment was measured using an instantaneous multi-photometric detector (MCPD-3000 manufactured by Otsuka Electronics Co., Ltd.) and evaluated according to the following criteria.
⊚: The display defect disappeared in less than 1 second.
◯: The display defect disappeared in 1 second or more and less than 10 seconds.
X: The display defect disappeared in 10 seconds or more.

<Durability>
The separator film of the adhesive polarizing plate was peeled off and attached to a 0.7 mm-thick non-alkali glass (1737 manufactured by Corning Inc.) using a laminator. Next, an autoclave treatment was performed at 50 ° C. and 0.5 MPa for 15 minutes to completely adhere the adhesive polarizing plate to the non-acrylic glass. Next, this was put under the conditions of a heating oven (heating) at 80 ° C. and a constant temperature / humidifier (humidifying) at 60 ° C./90% RH, and the presence or absence of peeling of the polarizing plate after 500 hours was described below. Evaluated by criteria.
⊚: No peeling was observed.
◯: Peeling that could not be visually confirmed was observed.
Δ: Small peeling that can be visually confirmed was observed.
X: Clear peeling was observed.

<Measurement of polarized light>
The separator film of the adhesive polarizing plate was peeled off and attached to a 0.7 mm-thick non-alkali glass (1737 manufactured by Corning Inc.) using a laminator. Next, an autoclave treatment was performed at 50 ° C. and 0.5 MPa for 15 minutes to completely adhere the adhesive polarizing plate to the non-acrylic glass. Then, it was put into a constant temperature and humidity chamber at 60 ° C./95% RH for 500 hours. The degree of polarization of the polarizing plate before and after the addition was measured using V7100 manufactured by JASCO Corporation, and the amount of change ΔP = (degree of polarization before addition)-(degree of polarization after addition) was determined. ..

In Table 1, in the alkali metal salt (B), "B-1" is a lithium bis (trifluoromethanesulfonyl) imide manufactured by Carlit Japan Co., Ltd., and "B-2" is a lithium perchloride manufactured by Carlit Japan Co., Ltd., "B-". 3 ”indicates 1-hexyl-4-methylpyridinium hexafluorophosphate manufactured by Kanto Chemical Co., Inc.
In the cross-linking agent (C), "C-1" is an isocyanate cross-linking agent manufactured by Mitsui Takeda Chemical Co., Ltd. (Takenate D110N, trimethylolpropane xylylene diisocyanate), and "C-2" is an isocyanate cross-linking agent manufactured by Nippon Polyurethane Industry Co., Ltd. ( Coronate L, trimethylolpropane tolylene diisocyanate adduct), and "C-3" indicate benzoyl peroxide (Niper BMT) manufactured by Nippon Polyurethane Industry Co., Ltd.
“D-1” in the silane coupling agent (D) indicates KBM403 manufactured by Shin-Etsu Chemical Co., Ltd.
“E-1” in the other compound (E) indicates Cyril SAT10 (number average molecular weight 4000) manufactured by Kaneka Corporation. "E-2" indicates polypropylene glucol (number average molecular weight 5000).

Claims (13)

An adhesive polarizing plate having a polarizing plate and an adhesive layer provided on the polarizing plate.
The polarizing plate has a transparent protective film only on one side of a polarizing element having a thickness of 10 μm or less, and the pressure-sensitive adhesive layer is provided on the polarizing element on the side that does not have the transparent protective film.
And the pressure-sensitive adhesive layer (except when storage elastic modulus (G ') is not less than 1.0 × ¹⁰ 6 Pa at 23 ° C.) is (meth) acrylic polymer (A) and an alkali metal salt (B ) Is formed from the pressure-sensitive adhesive composition containing
The alkali metal salt (B) is a lithium salt.
The lithium salt was contained in an amount of 0.001 to 4 parts by weight based on 100 parts by weight of the (meth) acrylic polymer (A).
The adhesive polarizing plate is obtained from the degree of polarization measured before and after 500 hours of charging into a constant temperature and humidity chamber at 60 ° C./95% RH. Formula: Change amount ΔP (%) = (Polarization degree (%) before charging ))-(Adhesive polarizing plate characterized in that the amount of change ΔP (%) represented by (degree of polarization (%) after injection) satisfies 0.05 or less. The adhesive polarizing plate according to claim 1, wherein the (meth) acrylic polymer (A) contains a hydroxyl group-containing monomer as a monomer unit. The adhesive polarizing plate according to claim 1 or 2, wherein the (meth) acrylic polymer (A) contains a carboxyl group-containing monomer as a monomer unit. The pressure-sensitive polarizing plate according to any one of claims 1 to 3, wherein the pressure-sensitive adhesive composition further contains a cross-linking agent (C). The adhesive polarizing plate according to claim 4, wherein the cross-linking agent (C) is contained in an amount of 0.01 to 20 parts by weight with respect to 100 parts by weight of the (meth) acrylic polymer (A). The adhesive polarizing plate according to claim 4 or 5, wherein the cross-linking agent (C) is at least one selected from an isocyanate compound and a peroxide. The invention according to any one of claims 1 to 6, wherein the silane coupling agent (D) is further contained in an amount of 0.001 to 5 parts by weight based on 100 parts by weight of the (meth) acrylic polymer (A). Adhesive polarizing plate. The adhesion according to any one of claims 1 to 7, further comprising 0.001 to 10 parts by weight of the polyether-modified silicone compound with respect to 100 parts by weight of the (meth) acrylic polymer (A). Type polarizing plate. The adhesive polarizing plate according to any one of claims 1 to 8, wherein the weight average molecular weight of the (meth) acrylic polymer (A) is 500,000 to 3,000,000. The pressure-sensitive polarizing plate according to any one of claims 1 to 9, wherein an easy-adhesion layer is provided between the polarizing plate and the pressure-sensitive adhesive layer. An image display device using at least one adhesive polarizing plate according to any one of claims 1 to 10. The method for producing an adhesive polarizing plate according to any one of claims 1 to 10.
A continuous web polarizing film made of a polyvinyl alcohol-based resin in which a dichroic substance is oriented, and a laminate containing a polyvinyl alcohol-based resin layer formed on a thermoplastic resin base material is subjected to aerial auxiliary stretching and boric acid water. A step of preparing a polarizer having a thickness of 10 μm or less obtained by stretching in a two-step stretching step consisting of stretching.
A step of obtaining the polarizing plate by laminating the transparent protective film only on one side of the polarizer, and
A method for producing an adhesive polarizing plate, which comprises a step of forming the pressure-sensitive adhesive layer on the side of the polarizing plate that does not have the transparent protective film. The step of forming the pressure-sensitive adhesive layer is
A method of transferring the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition to the polarizing plate, or
The method for producing a pressure-sensitive polarizing plate according to claim 12, wherein the pressure-sensitive adhesive composition is applied to the polarizing plate to form a pressure-sensitive adhesive layer.