JP2020126252A - Adhesive polarizing plate and image display device - Google Patents

Abstract

To provide an adhesive polarizing plate which has an adhesive layer having antistatic capability and satisfactory durability, and offers little deterioration in optical properties over time.SOLUTION: An adhesive polarizing plate is provided, comprising a polarizing plate and an adhesive layer provided on the polarizing plate, the polarizing plate having a transparent protective film provided only on one side of a polarizer. The adhesive layer is provided on the polarizer on a side without the transparent protective film, and is made of an adhesive composition containing a (meth)acrylic polymer (A) and an alkali metal salt (B).SELECTED DRAWING: None

Description

The present invention relates to a polarizing plate and an adhesive polarizing plate having an adhesive layer provided on the polarizing plate. Further, 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 dispose polarizing elements on both sides of a liquid crystal cell due to its image forming method, and in general, polarizing plates are attached. When the polarizing plate is attached to the liquid crystal cell, an adhesive is usually used. Further, in order to bond the polarizing plate and the liquid crystal cell with each other, in order to reduce the loss of light, the respective materials are adhered by using an adhesive. In such a case, since there is an advantage such as not requiring a drying step to fix the polarizing plate, the pressure-sensitive adhesive is a pressure-sensitive adhesive type polarizing plate provided in advance as an adhesive layer on one side of the polarizing plate. Commonly used. A release film is usually attached to the adhesive layer of the adhesive polarizing plate.

At the time of attaching the pressure-sensitive adhesive type polarizing plate to a liquid crystal cell during the production of a liquid crystal display device, the release film is peeled from the pressure-sensitive adhesive layer of the pressure-sensitive adhesive type polarizing plate, and static electricity is generated by peeling the release film. .. The static electricity thus generated affects the alignment of the liquid crystal inside the liquid crystal display device and causes a defect. Further, when the liquid crystal display device is used, display unevenness may occur due to static electricity. 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 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 pressure-sensitive adhesive layer. As means for imparting an antistatic function to the pressure-sensitive adhesive layer, for example, it has been proposed to blend an ionic compound into the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer (Patent Documents 1 to 4). In Patent Document 1, a lithium salt, in Patent Document 2, at least one of an alkali metal salt and an alkaline earth metal salt, in Patent Document 3, an ionic compound that has an organic cation and is solid at room temperature, and in Patent Document 4, an imidazolium cation. It is described that an ionic solid containing and an inorganic anion is blended with an acrylic pressure-sensitive adhesive used for a polarizing plate. Further, there has been proposed a method of providing an antistatic layer between a polarizing plate and a pressure-sensitive adhesive layer by using a binder of a conductive polymer such as polythiophene (Patent Document 5). Further, the adhesive polarizing plate is required to have durability in an adhesive state.

JP, 2010-189489, A JP, 2010-065217, A JP, 2010-066756, A JP, 2009-251281, A JP, 2003-246874, A

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 protective base materials such as transparent protective films on both sides of the polarizer are used.

On the other hand, as the pressure-sensitive adhesive type polarizing plate, a pressure-sensitive adhesive type polarizing plate provided with a pressure-sensitive adhesive layer may be used without providing a transparent protective film on only one side of the polarizer and providing a transparent protective film on the other side. Since such a pressure-sensitive adhesive type polarizing plate has a transparent protective film on only one side, it is possible to reduce the cost for one layer of the transparent protective film as compared with the case where the transparent protective film is provided on both sides, but the pressure-sensitive adhesive layer has an ionic compound. In the case of adding an antistatic function by containing, the influence of the ionic compound in the pressure-sensitive adhesive layer on the polarizer is large, for example, when an ionic liquid and an ionic solid are used as the ionic compound. However, there is a problem that the polarizer is deteriorated and the optical characteristics are largely deteriorated after the humidification test.

Also, when a layer containing a conductive polymer such as polythiophene is provided in 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 a pressure-sensitive adhesive type polarizing plate having an antistatic function and having a pressure-sensitive adhesive layer satisfying durability, and having little deterioration in optical characteristics.

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

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

That is, the present invention is a pressure-sensitive adhesive 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 only on one side of the polarizer, the pressure-sensitive adhesive layer is provided on the polarizer not having the transparent protective film, and the pressure-sensitive adhesive layer, (meta ) A pressure-sensitive adhesive type polarizing plate characterized by being formed from a pressure-sensitive adhesive composition containing an acrylic polymer (A) and an alkali metal salt (B).

In the pressure-sensitive adhesive type 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 pressure-sensitive adhesive type polarizing plate, a polarizer 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 resin in which a dichroic material is oriented, and includes a polyvinyl alcohol resin layer formed on a thermoplastic resin substrate. It is possible to use the one obtained by stretching the laminate in a two-stage stretching process consisting of auxiliary stretching in air and stretching in boric acid in water.

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

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

In the pressure-sensitive adhesive type polarizing plate, the pressure-sensitive adhesive composition may further contain a crosslinking agent. In the pressure-sensitive adhesive composition, the crosslinking agent (C) is preferably contained in an amount of 0.01 to 20 parts by weight based on 100 parts by weight of the (meth)acrylic polymer (A). The crosslinking 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 above-mentioned pressure-sensitive adhesive type polarizing plate may further contain 0.001 to 10 parts by weight of the polyether-modified silicone compound based on 100 parts by weight of the (meth)acrylic polymer (A).

In the pressure-sensitive adhesive type polarizing plate, the (meth)acrylic polymer (A) preferably has a weight average molecular weight of 500,000 to 3,000,000.

The pressure-sensitive adhesive type 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 by using at least one of the adhesive polarizing plates.

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

The pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer of the pressure-sensitive adhesive type 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 a 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 was found that by using the alkali metal salt (B), the antistatic function can be imparted without causing deterioration of the polarizer.

The pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer of the pressure-sensitive adhesive type 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 refers to 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. Examples of the alkyl group include 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 and an octadecyl group. These can be used alone or in combination. The average carbon number of these alkyl groups is preferably 3-9.

In addition, an alkyl (meth)acrylate containing an aromatic ring such as phenoxyethyl (meth)acrylate or benzyl (meth)acrylate is used in terms of adhesive properties, durability, adjustment of retardation, adjustment of refractive index, etc. be able to. The alkyl (meth)acrylate containing an aromatic ring can be used by mixing the polymer obtained by polymerizing the alkyl (meth)acrylate with the above-exemplified (meth)acrylic polymer, but contains an aromatic ring from the viewpoint of transparency. The alkyl(meth)acrylate is preferably used by copolymerizing with the alkyl(meth)acrylate.

The ratio of the alkyl (meth)acrylate containing an aromatic ring in the (meth)acrylic polymer (A) is 50 in the weight ratio of all the constituent monomers (100% by weight) of the (meth)acrylic polymer (A). It can be contained in a proportion of not more than wt %. Furthermore, 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 10 to 16% by weight. Weight percent 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 copolymerizable monomers can be introduced by copolymerization. Specific examples of such a copolymerization monomer include, for example, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and (meth)acrylic acid 6 -Hydroxyhexyl, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate and (4-hydroxymethylcyclohexyl)-methyl acrylate-containing monomer Carboxylic acid group-containing monomers such as (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid and crotonic acid; acid anhydrides such as maleic anhydride and itaconic anhydride Physical group-containing monomer; caprolactone adduct of acrylic acid; styrenesulfonic acid or allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl(meth)acrylate, ( Examples thereof include sulfonic acid group-containing monomers such as (meth)acryloyloxynaphthalene sulfonic acid; and phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate.

In addition, (N-substituted) amides such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylolpropane(meth)acrylamide, etc. Monomers: alkylaminoalkyl (meth)acrylate monomers such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate; (meth)acrylic (Meth)acrylic acid alkoxyalkyl monomers such as methoxyethyl acrylate and ethoxyethyl (meth)acrylate; N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, N-( Succinimide-based monomers such as (meth)acryloyl-8-oxyoctamethylenesuccinimide and N-acryloylmorpholine; maleimide-based monomers such as N-cyclohexylmaleimide and N-isopropylmaleimide, N-laurylmaleimide and N-phenylmaleimide; N-methylitacon Itaimide monomers such as imide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, and N-laurylitaconimide are also intended to be modified. Examples of the monomer of

Further as the modifying monomer, vinyl acetate, vinyl propionate, N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole, vinylmorpholine, N- Vinyl carboxylic acid amides, vinyl-based monomers such as 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 polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, and methoxypolypropylene glycol (meth)acrylate; tetrahydrofurfuryl (meth)acrylate, Acrylic 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.

Furthermore, examples of copolymerizable monomers other than the above include silane-based monomers containing a silicon atom. Examples of the silane-based monomer include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, 8-vinyloctyltrimethoxysilane. , 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, 10-acryloyloxydecyltriethoxysilane and the like.

Further, as the copolymerization monomer, tripropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, bisphenol A diglycidyl ether di(meth)acrylate, neo Pentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate , Polyfunctional having two or more unsaturated double bonds such as (meth)acryloyl groups and vinyl groups such as esterification products of (meth)acrylic acid such as caprolactone-modified dipentaerythritol hexa(meth)acrylate and polyhydric alcohols (Meth)acrylates and epoxies (two or more unsaturated double bonds such as (meth)acryloyl groups and vinyl groups) that have the same functional groups as the monomer components are added to the skeletons of organic monomers and polyesters, epoxies, urethanes, etc. It is also possible to use (meth)acrylate, urethane (meth)acrylate and the like.

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

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

When a hydroxyl group-containing monomer is contained as a 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 the 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, one having a weight average molecular weight of 500,000 to 3,000,000 is usually used. In consideration of 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 2,500,000. When the weight average molecular weight is less than 500,000, it is not preferable in terms of heat resistance. If the weight average molecular weight is more than 3,000,000, a large amount of diluting solvent is required to adjust the viscosity for coating, which is not preferable because the cost is increased. 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 polymerization 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 the solution polymerization, ethyl acetate, toluene, etc. are used as the polymerization solvent. As a specific example of solution polymerization, the reaction is carried out under a flow of an inert gas such as nitrogen, a polymerization initiator is added, and the reaction is usually performed at about 50 to 70° C. for 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 polymerization initiator, the amount of chain transfer agent used, and the reaction conditions. It

Examples of the polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis(2-amidinopropane)dihydrochloride, 2,2′-azobis[2-(5-methyl-2) -Imidazolin-2-yl)propane]dihydrochloride, 2,2'-azobis(2-methylpropionamidine)disulfate, 2,2'-azobis(N,N'-dimethyleneisobutylamidine),2,2 '-Azobis[N-(2-carboxyethyl)-2-methylpropionamidine]hydrate (VA-057 manufactured by Wako Pure Chemical Industries, Ltd.) and other azo initiators, potassium persulfate, ammonium persulfate and other persulfates , Di(2-ethylhexyl)peroxydicarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, di-sec-butylperoxydicarbonate, t-butylperoxy neodecanoate, t-hexylper Oxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, di(4 -Methylbenzoyl)peroxide, dibenzoylperoxide, t-butylperoxyisobutyrate, 1,1-di(t-hexylperoxy)cyclohexane, t-butylhydroperoxide, peroxides such as hydrogen peroxide Examples of the initiator include, but are not limited to, a redox initiator in which a peroxide and a reducing agent are combined, such as a combination of an initiator, a persulfate salt and sodium bisulfite, and a combination of a peroxide and sodium ascorbate. 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. The amount is preferably about 0.02 to 0.5 part by weight, and more preferably about 0.02 to 0.5 part by weight.

In addition, in order to produce the (meth)acrylic polymer (A) having the above-mentioned weight average molecular weight by using, for example, 2,2′-azobisisobutyronitrile as a polymerization initiator, the amount of the polymerization initiator used is Is preferably about 0.06 to 0.2 parts by weight, and 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 thioglycolate, and 2,3-dimercapto-1-propanol. The chain transfer agent may be used alone or in combination of two or more, but the total content is 0.1 parts by weight based on 100 parts by weight of the total amount of the monomer components. It is below the level.

Further, as the emulsifier used in the case of emulsion polymerization, for example, sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, ammonium polyoxyethylene alkyl ether sulfate, anionic emulsifiers such as sodium polyoxyethylene alkylphenyl ether sulfate, polyoxy Examples thereof include nonionic emulsifiers such as ethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, and polyoxyethylene-polyoxypropylene block polymer. These emulsifiers may be used alone or in combination of two or more kinds.

Furthermore, as a reactive emulsifier, as an emulsifier having a radically polymerizable functional group such as a propenyl group or an allyl ether group introduced therein, specifically, for example, Aqualon HS-10, HS-20, KH-10, BC-05. , BC-10, BC-20 (all of which are manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) and ADEKA REASOAP SE10N (manufactured by Asahi Denka Co., Ltd.). Since the reactive emulsifier is incorporated into the polymer chain after the polymerization, the water resistance is improved, which is preferable. The emulsifier is preferably used in an amount of 0.3 to 5 parts by weight, more preferably 0.5 to 1 part by weight, based on 100 parts by weight of the total amount of the monomer components, in view of polymerization stability and mechanical stability.

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

The anion part of the alkali metal salt (B) may be composed of an organic material or an inorganic material. Examples of the anion moiety 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 ⁻ , (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 are used. In particular, the anion moiety containing a fluorine atom is preferably used because an ionic compound having a good ion dissociation property can be obtained. As the anion part constituting the inorganic salt, Cl ⁻ , Br ⁻ , I ⁻ , AlCl ₄ ⁻ , Al ₂ Cl ₇ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , NO ₃ ⁻ , AsF ₆ ⁻ , SbF. ₆ ⁻ , NbF ₆ ⁻ , TaF ₆ ⁻ , (CN) ₂ N ⁻ , and the like are used. Examples of the anionic ^{_{portion, (CF 3 SO 2) 2}} N -, (C 2 F 5 SO 2) 2 N - etc. (perfluoroalkyl sulfonyl) imide are preferable, and _{(CF 3 SO 2) 2 N} -, in formula (Trifluoromethanesulfonyl)imide is preferred.

The alkali metal organic salt, specifically, sodium acetate, sodium alginate, sodium lignin sulfonate, sodium toluene _{sulfonate, LiCF 3 SO 3, Li (} CF 3 SO 2) 2 N, 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, Li (CF 3 SO 2)} 2 N, Li (C 2 F 5 SO 2) 2 N, Li (C 4 F 9 SO ₂ ) A fluorine-containing lithium imide salt such as ₂ N is more preferable, and a (perfluoroalkylsulfonyl)imide lithium salt is particularly preferable.

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

The proportion 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 amount of the alkali metal salt (B) is less than 0.001 part by weight, the antistatic performance may not be sufficiently improved. 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 be insufficient. The amount of the alkali metal salt (B) is preferably 3 parts by weight or less, and more preferably 1 part by weight or less. The ratio of the alkali metal salt (B) can be set to 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 crosslinking agent (C). As the crosslinking agent (C), an organic crosslinking agent or a polyfunctional metal chelate can be used. Examples of the organic crosslinking agent include isocyanate crosslinking agents, peroxide crosslinking agents, epoxy crosslinking agents, imine crosslinking agents and the like. The polyfunctional metal chelate is a polyvalent metal having a covalent bond or a coordinate bond with an organic compound. Examples of polyvalent metal atoms include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn and Ti. Can be mentioned. Examples of the atom in the organic compound that forms a covalent bond or a coordinate 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 crosslinking agent (C), an isocyanate crosslinking agent and/or a peroxide type crosslinking agent are preferable. Examples of the compound related to the isocyanate-based crosslinking agent include tolylene diisocyanate, chlorphenylene diisocyanate, tetramethylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, and isocyanate monomers such as hydrogenated diphenylmethane diisocyanate and these isocyanate monomers. Isocyanate compounds and isocyanurates added with trimethylolpropane, burette type compounds, and further urethane polyols such as polyether polyols, polyester polyols, acrylic polyols, polybutadiene polyols, polyisoprene polyols, and the like, urethane prepolymer type isocyanates 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 therefrom. Here, hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, and a polyisocyanate compound derived from one selected from the group consisting of isophorone diisocyanate, hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, polyol modified Hexamethylene diisocyanate, polyol modified hydrogenated xylylene diisocyanate, trimer type hydrogenated xylylene diisocyanate, polyol modified isophorone diisocyanate and the like are included. The exemplified polyisocyanate compounds are preferable because they contribute rapidly to the cross-linking speed because the reaction with the hydroxyl group proceeds rapidly, especially by using the acid or base contained in the polymer as a catalyst.

The peroxide can be appropriately used as long as it generates a radical active species by heating or light irradiation to promote crosslinking of the base polymer of the pressure-sensitive adhesive composition, but in consideration of workability and stability. It is preferable to use a peroxide having a one-minute half-life temperature of 80°C to 160°C, more preferably 90°C to 140°C.

Examples of peroxides that can be used include di(2-ethylhexyl)peroxydicarbonate (1 minute half-life temperature: 90.6° C.), di(4-t-butylcyclohexyl)peroxydicarbonate (1 Minute half-life temperature: 92.1° C.), di-sec-butyl peroxydicarbonate (1 minute half-life temperature: 92.4° C.), t-butyl peroxy neodecanoate (1 minute half-life temperature: 103 0.5° 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: 116.4°C), di-n-octanoyl peroxide (1-minute half-life 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, since the crosslinking reaction efficiency is particularly excellent, di(4-t-butylcyclohexyl)peroxydicarbonate (1 minute half-life temperature: 92.1° C.), dilauroyl peroxide (1 minute half-life temperature: 116. 4° C.), dibenzoyl peroxide (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 catalogs, and for example, “Fluids and Oil Co., Ltd. “Organic peroxide catalog 9th edition”. (May 2003)” and the like.

The amount of the crosslinking 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). When the amount of the cross-linking agent (C) is less than 0.01 parts by weight, the cohesive force of the pressure-sensitive adhesive tends to be insufficient, and foaming may occur during heating. On the other hand, when it is more than 20 parts by weight, sufficient moisture resistance is obtained. Instead, peeling is likely to occur in a reliability test or the like.

The above isocyanate-based cross-linking agents may be used alone or in combination of two or more, but the total content is the (meth)acrylic polymer (A)100. The polyisocyanate compound crosslinking 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 even more preferably 0.05 to 1.5 parts by weight. More preferably, it is contained in parts by weight. It may be appropriately contained in consideration of cohesive force, prevention of peeling in a durability test, and the like.

The above-mentioned peroxides may be used alone or in combination of two or more, but the total content is 100 parts 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. .. In order to adjust workability, reworkability, cross-linking stability, releasability, etc., it is appropriately selected within this range.

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 for measurement.

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

Further, the pressure-sensitive adhesive composition of the present invention can contain a silane coupling agent (D). The 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, and 2-(3. Epoxy group-containing silane coupling agent such as 4-epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl- Amino group-containing silane coupling agents such as N-(1,3-dimethylbutylidene)propylamine, N-phenyl-γ-aminopropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltri Examples thereof include (meth)acrylic group-containing silane coupling agents such as ethoxysilane, and isocyanate group-containing silane coupling agents such as 3-isocyanatopropyltriethoxysilane.

The silane coupling agent (D) may be used alone, or two or more kinds may be mixed and used, but the total content 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 still more preferably 0.05 to 1 part by weight. ˜0.6 parts by weight is preferred. It is an amount that improves durability and maintains an appropriate adhesive force to an optical member such as a liquid crystal cell.

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 2010-275522A can be used.

The polyether-modified silico compound has a polyether skeleton, and has at least one terminal represented by 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 as 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.

As the polyether-modified silicone compound,
Formula _{(2): R a M 3} -a Si-X-Y- (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 as 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. Represents a linear or branched oxyalkylene group having 1 to 10 carbon atoms, n is 1 to 1700, and represents the average number of moles of the added oxyalkylene group, and X represents a linear chain having 1 to 20 carbon atoms or It represents a branched alkylene group, and Y represents an ether bond, an ester bond, a urethane bond, or a carbonate bond.
Z is a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms,
Formula _{(2A): - Y 1 -X} -SiR a M 3-a
(In the formula, R, M, and X are the same as the above. Y ¹ represents a single bond, a -CO- bond, a -CONH- bond, or a -COO- bond.), or
Formula _{(2B): - Q {-} (OA) n -Y-X-SiR a M 3-a} m
(In the formula, R, M, X and Y are the same as the above. OA is the same as the above AO and n is the same as the above. Q is a divalent or higher valent hydrocarbon group having 1 to 10 carbon atoms. , M are the same as the valence of the hydrocarbon group.). ).

Specific examples of the polyether-modified silico compound include MS polymers S203, S303, S810; SILYL EST250, EST280; SAT10, SAT200, SAT220, SAT350, SAT400, EXCESTAR S2410, S2420 or S3430 manufactured by Asahi Glass Co., Ltd. Etc.

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

The pressure-sensitive adhesive composition is used to form a pressure-sensitive adhesive layer. In forming the pressure-sensitive adhesive layer, it is necessary to carefully consider the effects of the crosslinking treatment temperature and the crosslinking treatment time while adjusting the addition amount of the entire crosslinking agent. preferable.

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

In addition, the crosslinking treatment may be performed at the temperature during the drying step of the pressure-sensitive adhesive layer, or may be performed by separately providing a crosslinking treatment step after the drying step.

The crosslinking 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.

The pressure-sensitive adhesive type polarizing plate of the present invention is provided with a transparent protective film only on one side of the polarizer and a transparent protective film is not provided on the other side of the polarizer, and the pressure-sensitive adhesive layer is formed on the polarizer by the pressure-sensitive adhesive composition. It is a thing.

As a method for forming a pressure-sensitive adhesive layer, for example, a method in which the pressure-sensitive adhesive composition is applied to a release-treated separator or the like, and a polymerization solvent or the like is dried to form a pressure-sensitive adhesive layer, and then transferred to a polarizing plate, or The adhesive composition is applied to a polarizing plate, and the polymerization solvent and the like are dried and removed to form an 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 forming the pressure-sensitive adhesive layer by applying the adhesive composition of the present invention on such a liner, and drying the pressure-sensitive adhesive layer, as a method for drying the pressure-sensitive adhesive, an appropriate method is adopted depending on the purpose. obtain. Preferably, a method of heating the above coating film by heating 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 pressure-sensitive adhesive properties can be obtained.

As the drying time, an appropriate time can be appropriately adopted. 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, the pressure-sensitive adhesive layer can be formed on the surface of the polarizing plate after forming an anchor layer or after performing various types of easy adhesion treatment such as corona treatment and plasma treatment. Further, the surface of the pressure-sensitive adhesive layer may be subjected to easy adhesion treatment.

Various methods are used 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 of the method include 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. The thickness is preferably 2 to 50 μm, more preferably 2 to 40 μm, and further preferably 5 to 35 μm.

When the pressure-sensitive adhesive layer is exposed, the pressure-sensitive adhesive layer may be protected by a release-treated sheet (separator) until practical use.

As a constituent material of the separator, for example, a plastic film such as polyethylene, polypropylene, polyethylene terephthalate, or a polyester film, a porous material such as paper, cloth, or a non-woven fabric, a net, a foamed sheet, a metal foil, or a laminated body thereof is appropriately used. The thin film may be used, but a plastic film is preferably used because of its excellent surface smoothness.

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

The thickness of the separator is usually 5 to 200 μm, preferably about 5 to 100 μm. In the separator, if necessary, a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based release agent, release and antifouling treatment with silica powder or the like, coating type, kneading type, vapor deposition type It is also possible to perform antistatic treatment such as. Particularly, 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 peelability from the pressure-sensitive adhesive layer can be further enhanced.

The release-treated sheet used in the production of the pressure-sensitive adhesive type polarizing plate can be used as it is as a separator of the pressure-sensitive adhesive type polarizing plate, and the process can be simplified.

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

The polarizer is not particularly limited, and various kinds can be used. Examples of the polarizer include hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene/vinyl acetate copolymer partially saponified films, and dichroic dyes such as iodine and dichroic dyes. Examples thereof include polyene oriented films such as those obtained by adsorbing a substance and uniaxially stretched, polyvinyl alcohol dehydrated products, polyvinyl chloride dehydrochlorinated products, and the like. Among these, a polarizer made of a polyvinyl alcohol 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 obtained by dyeing a polyvinyl alcohol-based film with iodine and uniaxially stretching it can be produced, for example, by dyeing polyvinyl alcohol by immersing it in an aqueous solution of iodine and stretching it to 3 to 7 times its original length. If necessary, it may 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 film may be immersed in water and washed with water before dyeing. By washing the polyvinyl alcohol-based film with water, it is possible to wash the stains and antiblocking agents on the surface of the polyvinyl alcohol-based film, and by swelling the polyvinyl alcohol-based film, the effect of preventing unevenness such as uneven dyeing is also provided. is there. Stretching may be performed after dyeing with iodine, stretching while dyeing, or stretching and then dyeing with iodine. Stretching can be performed in an aqueous solution of boric acid or potassium iodide or in a water bath.

A thin polarizer having a thickness of 10 μm or less can be used as the polarizer. From the viewpoint of thinning, the thickness is preferably 1 to 7 μm. It is preferable that such a thin polarizer has less unevenness in thickness, is excellent in visibility, and is small in dimensional change, is excellent in durability, and can be thinned as a polarizing plate.

As the thin polarizer, typically, JP-A-51-0696644, JP-A-2000-338329, WO 2010/100917, PCT/JP2010/001460, or Japanese Patent Application No. 2010- Examples thereof include thin polarizing films described in Japanese Patent No. 269002 and 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 stretching resin base material in a laminate state and a dyeing step. According to this production method, even if the PVA-based resin layer is thin, it can be stretched without trouble such as breakage due to stretching because it is supported by the stretching resin base material.

As the thin polarizing film, among manufacturing methods including a step of stretching in a laminate state and a step of dyeing, WO2010/100917 pamphlet, PCT/ Those obtained by a production method including a step of stretching in a boric acid aqueous solution as described in JP 2010/001460, or Japanese Patent Application Nos. 2010-269002 and 2010-263692 are preferable, and particularly preferable. Those obtained by a production method including a step of supplementary in-air stretching before stretching in a boric acid aqueous solution described in Japanese Patent Application No. 2010-269002 and Japanese Patent Application No. 2010-263692 are preferable.

The thin high-performance polarizing film described in the specification of PCT/JP2010/001460 is a thin film having a thickness of 7 μm or less, which is made of a PVA-based resin in which a dichroic material is oriented and which is integrally formed on a resin substrate. It is a high-performance polarizing film, and has optical characteristics of a single transmittance of 42.0% or more and a polarization degree of 99.95% or more.

The thin high-performance polarizing film is such that a PVA-based resin layer is formed by coating and drying a PVA-based resin on a resin substrate having a thickness of at least 20 μm, and the generated PVA-based resin layer is dyed with a dichroic material. Dip the PVA-based resin layer to the PVA-based resin layer, and the PVA-based resin layer on which the dichroic substance has been adsorbed is integrated with the resin base material in the aqueous boric acid solution so that the total draw ratio is the original length. It can be manufactured by stretching so as to be 5 times or more.

A method for producing a laminate film including a thin high-performance polarizing film in which a dichroic material is oriented, comprising a resin base material having a thickness of at least 20 μm and a PVA-based resin on one surface of the resin base material. A step of producing a laminate film including a PVA-based resin layer formed by applying and drying an aqueous solution, and the above-described laminate including a resin base material and a PVA-based resin layer formed on one surface of the resin base material A step of adsorbing the dichroic substance to the PVA-based resin layer contained in the laminate film by immersing the film in a dyeing solution containing the dichroic substance, and a PVA-based resin adsorbing the dichroic substance A step of stretching the laminate film containing layers in an aqueous solution of boric acid so that the total stretching ratio is 5 times or more of the original length; and a PVA-based resin layer having a dichroic substance adsorbed thereon is a resin base material. The PVA resin layer in which a dichroic material is oriented is formed on one surface of the resin substrate by being integrally stretched with, and the thickness is 7 μm or less, the single transmittance is 42.0% or more and the polarization degree is 99. The thin high-performance polarizing film can be produced by including a step of producing a laminated film having a thin high-performance polarizing film having an optical property of 0.95% or more.

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

The thin polarizing film of Japanese Patent Application No. 2010-269002 or Japanese Patent Application No. 2010-263692 is a continuous web polarizing film made of a PVA-based resin in which a dichroic material is oriented, and is amorphous. The laminate containing the PVA-based resin layer formed on the ester-based thermoplastic resin substrate was stretched in a two-stage stretching process consisting of auxiliary stretching in air and stretching in boric acid in water to have a thickness of 10 μm or less. It is a thing. Such a thin polarizing film has P>−(10 ^0.929 T ^−42.4 −1)×100 (where T<42.3), and P≧, where T is the single transmittance and P is the polarization degree. It is preferable that the optical characteristics are such that the condition of 99.9 (where T≧42.3) is satisfied.

Specifically, the thin polarizing film is a stretched intermediate layer formed of an oriented PVA-based resin layer by high-temperature in-air stretching of a PVA-based resin layer formed on an amorphous ester-based thermoplastic resin substrate of a continuous web. A colored intermediate product comprising a PVA-based resin layer in which a dichroic material (iodine or a mixture of iodine and an organic dye is preferred) is oriented by a step of forming a product and adsorption of the dichroic material to the stretched intermediate product. Thin polarizing film including a step of producing a product and a step of producing a polarizing film having a thickness of 10 μm or less, which is composed of a PVA-based resin layer in which a dichroic material is oriented, by stretching in water 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 stretching ratio of the PVA-based resin layer formed on the amorphous ester-based thermoplastic resin substrate by high-temperature in-air stretching and in-boric-acid-water stretching is set to 5 times or more. desirable. The liquid temperature of the boric acid aqueous solution for drawing in boric acid in water can be 60° C. or higher. Before stretching the colored intermediate product in the aqueous boric acid solution, it is desirable to subject the colored intermediate product to an insolubilization treatment. In that case, the colored intermediate product is added to the aqueous boric acid solution whose liquid temperature does not exceed 40°C. It is desirable to do so by immersing. The amorphous ester-based thermoplastic resin substrate is an amorphous polyethylene containing a copolymerized polyethylene terephthalate copolymerized with isophthalic acid, a copolymerized polyethylene terephthalate copolymerized with cyclohexanedimethanol or another copolymerized polyethylene terephthalate. It can be terephthalate and is 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. In addition, the draw ratio of the in-air high temperature drawing is preferably 3.5 times or less, and the drawing temperature of the in-air high temperature drawing is preferably the glass transition temperature of the PVA-based resin or higher, specifically in the range of 95°C to 150°C. When the in-air high-temperature stretching 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 substrate is preferably 5 times or more and 7.5 times or less. .. When the in-air high-temperature stretching is performed by fixed-end uniaxial stretching, the total stretching ratio of the PVA-based resin layer formed on the amorphous ester-based thermoplastic resin substrate is 5 times or more and 8.5 times or less. Is preferred.
More specifically, a thin polarizing film can be manufactured by the following method.

A base material for a continuous web of isophthalic acid copolymerized polyethylene terephthalate (amorphous PET) in which 6 mol% of isophthalic acid is copolymerized is prepared. The glass transition temperature of amorphous PET is 75°C. A laminate consisting of a continuous web amorphous PET substrate and a polyvinyl alcohol (PVA) layer is prepared as follows. Incidentally, the glass transition temperature of PVA is 80°C.

An amorphous PET base material having a thickness of 200 μm and a PVA aqueous solution having a concentration of 4 to 5% in which PVA powder having a polymerization degree of 1000 or more and a saponification degree of 99% or more is dissolved in water are prepared. Next, a 200 μm-thick amorphous PET base material is coated with a PVA aqueous solution 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 laminate containing a 7 μm thick PVA layer is subjected to the following steps including a two-stage drawing step of auxiliary drawing in air and drawing in boric acid in water to produce a thin highly functional polarizing film having a thickness of 3 μm. The first stage in-air auxiliary stretching step integrally stretches the laminate including the PVA layer having a thickness of 7 μm with the amorphous PET substrate to produce a stretched laminate including the PVA layer having a thickness of 5 μm. Specifically, this stretched laminate is subjected to a stretch ratio of 1.8 by subjecting the laminate including the PVA layer having a thickness of 7 μm to a stretching device provided in an oven set to a stretching temperature environment of 130° C. The free end is uniaxially stretched. By this stretching treatment, the PVA layer contained in the stretched laminate is changed to a PVA layer having a thickness of 5 μm in which PVA molecules are oriented.

Next, in the dyeing step, a colored laminate is produced in which iodine is adsorbed on a PVA layer having a thickness of 5 μm in which PVA molecules are oriented. Specifically, in this colored laminate, the stretched laminate was immersed in 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 highly functional polarizing film finally produced. Is soaked as to be 40 to 44% for an arbitrary time so that iodine is adsorbed to the PVA layer contained in the stretched laminate. In this step, the dyeing solution has water as a solvent, an iodine concentration of 0.12 to 0.30% by weight, and a potassium iodide concentration of 0.7 to 2.1% by weight. The ratio of the concentrations of iodine and potassium iodide is 1:7. By the way, potassium iodide is needed 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 the 5 μm-thick PVA layer in which PVA molecules were oriented. To produce a colored laminate.

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

Although it is not an essential step for manufacturing the optical film laminate, the optical film laminate was taken out from the aqueous boric acid solution by a washing step and attached 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 potassium iodide solution. Then, the washed optical film laminate is dried by a drying process using warm air at 60°C. The cleaning step is a step for eliminating a poor appearance such as boric acid precipitation.

Similarly, although it is not an essential step in the production of the optical film laminate, an adhesive is applied to the surface of the PVA layer having a thickness of 3 μm formed on the amorphous PET substrate by a laminating and/or transferring step. However, after adhering a triacetyl cellulose film having a thickness of 80 μm, the amorphous PET substrate is peeled off, and the PVA layer having a thickness of 3 μm can be transferred to the triacetyl cellulose film having a thickness of 80 μm.

[Other processes]
The above thin polarizing film manufacturing method 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 may be performed at any appropriate timing.
The insolubilization step is typically performed by immersing the PVA-based resin layer in an aqueous boric acid solution. By performing the insolubilization treatment, water resistance can be imparted to the PVA-based resin layer. The concentration of the aqueous boric acid solution is preferably 1 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 laminated body is produced and before the dyeing step and the underwater stretching step.
The cross-linking step is typically performed by immersing the PVA-based resin layer in an aqueous boric acid solution. Water resistance can be imparted to the PVA-based resin layer by performing the crosslinking treatment. The concentration of the aqueous boric acid solution is preferably 1 to 4 parts by weight with respect to 100 parts by weight of water. When the crosslinking step is performed after the dyeing step, it is preferable to further add iodide. By blending iodide, elution of iodine adsorbed on the PVA-based resin layer can be suppressed. The iodide content 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 crosslinking bath (boric acid aqueous solution) is preferably 20°C to 50°C. Preferably, the crosslinking step is performed before the second in-boric-acid-water drawing step. In a preferred embodiment, the dyeing step, the cross-linking step, and the second in-boric-acid-water drawing step are performed in this order.

As a material forming 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 a thermoplastic resin 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 include polyolefin resins (norbornene-based resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. One or more kinds of any appropriate additive may be contained in the transparent protective film. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a 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, further 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 and other properties inherent in the thermoplastic resin may not be sufficiently exhibited.

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

Further, the polarizing plate can be laminated with another optical film. As other optical films, for example, for forming liquid crystal display devices such as a reflection plate, an anti-transmission plate, a retardation plate (including a wavelength plate such as 1/2 or 1/4), a visual compensation film, and a brightness enhancement film. Examples thereof include those used as optical layers that may be used. These may be laminated on the polarizing plate for practical use to use one layer or two or more layers.

The optical film in which the optical layer is laminated on the 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. It is excellent in stability and assembling work, and has the advantage that the manufacturing process of liquid crystal display devices can be improved. Appropriate adhesion means such as an adhesive layer may be used for lamination. When the above-mentioned polarizing plate and other optical layers are adhered, their optical axes can be arranged at appropriate angles depending on the intended retardation characteristics and the like.

The adhesive polarizing plate of the present invention can be preferably used for forming various image display devices such as liquid crystal display devices. The liquid crystal display device can be formed in a conventional manner. That is, a 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 an illumination system and incorporating a drive circuit. In the above, there is no particular limitation except that the pressure-sensitive adhesive type polarizing plate according to the present invention is used, and the conventional method can be applied. The liquid crystal cell may be of any type such as TN type, STN type, π type, VA type, IPS type, or any other type.

It is possible to form an appropriate liquid crystal display device such as a liquid crystal display device in which an adhesive polarizing plate is arranged on one side or both sides of a display panel such as a liquid crystal cell, or a backlight system or a reflection plate is used for an illumination system. 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 optical films are provided on both sides, they may be the same or different. Furthermore, when forming a liquid crystal display device, for example, a diffusion plate, an anti-glare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffusion plate, a backlight, and other appropriate components are provided at appropriate positions in a single layer or Two or more layers can be arranged.

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In addition, all parts and% in each example are based on weight. Unless otherwise specified, the room temperature storage condition is 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: Tosoh Corp., HLC-8120GPC
・Column: G7000H _XL + GMH _XL + GMH _XL manufactured by Tosoh Corporation
・Column size: 7.8 mmφ×30 cm each, 90 cm in total
・Column temperature: 40℃
・Flow rate: 0.8 ml/min
・Injection volume: 100 μl
・Eluent: Tetrahydrofuran ・Detector: Differential refractometer (RI)
・Standard sample: polystyrene

<Creation of polarizing plate (1)>
In order to manufacture a thin polarizing film, first, a laminated body in which a PVA layer having a thickness of 9 μm is formed on an amorphous PET substrate is subjected to in-air auxiliary stretching at a stretching temperature of 130° C. to form a stretched laminated body, and then stretched. The laminated body is dyed to form a colored laminated body, and further, the colored laminated body is stretched integrally with the amorphous PET substrate by stretching in a boric acid solution at a stretching temperature of 65° C. so that the total stretching ratio becomes 5.94 times. An optical film laminate including a 4 μm thick PVA layer was produced. The PVA molecules in the PVA layer formed on the amorphous PET substrate by such a 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 including a PVA layer having a thickness of 4 μm, which constitutes a highly functional 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 was attached, and then the amorphous PET substrate was 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 stretched up to 3 times while being dyed in a 0.3% concentration iodine solution at 30° C. for 1 minute between rolls having different speed ratios. Then, while being immersed in an aqueous solution containing 60° C., 4%-concentration boric acid and 10%-concentration potassium iodide for 0.5 minutes, it was stretched to a total stretching ratio of 6 times. Then, the plate 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. A 40 μm-thick saponified triacetyl cellulose film was attached to one surface of the polarizer with a polyvinyl alcohol-based adhesive to form a polarizing plate. Hereinafter, this is referred to as a TAC-based polarizing plate (2).

Production example 1
<Preparation of acrylic polymer (A1)>
A monomer mixture containing 82 parts of butyl acrylate, 15 parts of benzyl acrylate, and 3 parts of 4-hydroxybutyl acrylate was charged into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a condenser. Further, to 100 parts of the monomer mixture (solid content), 0.1 part of 2,2′-azobisisobutyronitrile as a polymerization initiator was charged together with ethyl acetate, and nitrogen gas was introduced while gently stirring. After nitrogen substitution, the liquid temperature in the flask was maintained at around 60° C. to carry out a polymerization reaction 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 1,000,000, which was adjusted to a solid content concentration of 30%.

Production example 2
<Preparation of acrylic polymer (A-2)>
In Production Example 1, as the monomer mixture, 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. A solution of the acrylic polymer (A2) having a weight average molecular weight of 1,000,000 was prepared in the same manner as in Production Example 1 except for the above.

Production 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. Similarly to the above, a solution of an acrylic polymer (A2) having a weight average molecular weight of 1,000,000 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 Japan Carlit Co., Ltd.) was added, and further tri Methylolpropane xylylene diisocyanate (Mitsui Chemicals: Takenate D110N) 0.1 part, dibenzoyl peroxide 0.3 parts, γ-glycidoxypropyl methoxysilane (Shin-Etsu Chemical Co., Ltd.: KBM-403) 0 0.075 parts was blended to prepare an acrylic pressure-sensitive adhesive solution.

(Preparation of adhesive polarizing plate)
Then, the acrylic adhesive solution is uniformly applied to the surface of a polyethylene terephthalate film (separator film) treated with a silicone release agent with a fountain coater, and dried for 2 minutes in an air circulating constant temperature oven at 155°C. Then, an 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 polarizing film side of the polarizer of the thin polarizing plate (1) prepared above to prepare a pressure-sensitive adhesive type polarizing plate.

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

The adhesive polarizing plates obtained in the above Examples and Comparative Examples were evaluated as follows. The evaluation results are shown in Table 1.

<Surface resistance: 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 pressure-sensitive 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 static electricity of 5 kv was generated by using an electrostatic discharge device, ESD (ESD-8012A, manufactured by SANKI Co., Ltd.) to cause liquid crystal alignment disorder. The recovery time (second) of the display defect due to the alignment defect was measured using an instant 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 pressure-sensitive adhesive type polarizing plate was peeled off and attached to a 0.7 mm-thick non-alkali glass (Corning Co., 1737) using a laminator. Then, autoclave treatment was carried out at 50° C. and 0.5 MPa for 15 minutes to completely adhere the pressure-sensitive adhesive type polarizing plate to the acrylic-free glass. Then, this was put under the conditions of a heating oven (heating) at 80° C. and a constant temperature and humidity machine (humidification) at 60° C./90% RH, and the presence or absence of peeling of the polarizing plate after 500 hours was determined as It was evaluated according to the standard.
⊚: No peeling was observed.
◯: Peeling that could not be visually confirmed was observed.
Δ: Small peeling that can be visually confirmed was recognized.
X: Clear peeling was recognized.

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

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

Claims (15)

A pressure-sensitive adhesive type 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 only on one side of a polarizer having a thickness of 10 μm or less, and the pressure-sensitive adhesive layer is provided on the polarizer not having the transparent protective film.
In addition, the pressure-sensitive adhesive layer (excluding the case where the storage elastic modulus (G′) is 1.0×10 ⁶ Pa or more at 23° C.) is composed of the (meth)acrylic polymer (A) and the alkali metal salt (B). ) Is formed from a pressure-sensitive adhesive composition containing,
The pressure-sensitive adhesive polarizing plate is obtained from the degree of polarization measured before and after being placed in a thermo-hygrostat at 60° C./95% RH for 500 hours. Formula: variation ΔP(%)=(degree of polarization before addition (% ))-(Adjustment type polarizing plate characterized by satisfying a change amount ΔP (%) represented by (degree of polarization (%) after charging) of 0.05 or less. The pressure-sensitive adhesive polarizing plate according to claim 1, wherein the alkali metal salt (B) is a lithium salt. The pressure-sensitive adhesive polarizing plate according to claim 1, which contains 0.001 to 5 parts by weight of the alkali metal salt (B) with respect to 100 parts by weight of the (meth)acrylic polymer (A). The pressure-sensitive adhesive polarizing plate according to claim 1, wherein the (meth)acrylic polymer (A) contains a hydroxyl group-containing monomer as a monomer unit. The pressure-sensitive adhesive polarizing plate according to any one of claims 1 to 4, wherein the (meth)acrylic polymer (A) contains a carboxyl group-containing monomer as a monomer unit. The pressure-sensitive adhesive type polarizing plate according to any one of claims 1 to 5, wherein the pressure-sensitive adhesive composition further contains a cross-linking agent (C). The pressure-sensitive adhesive type polarizing plate according to claim 6, wherein the crosslinking agent (C) is contained in an amount of 0.01 to 20 parts by weight based on 100 parts by weight of the (meth)acrylic polymer (A). The pressure-sensitive adhesive type polarizing plate according to claim 6 or 7, wherein the crosslinking agent (C) is at least one selected from an isocyanate compound and a peroxide. The silane coupling agent (D) is further contained in an amount of 0.001 to 5 parts by weight with respect to 100 parts by weight of the (meth)acrylic polymer (A). Adhesive polarizing plate. The pressure-sensitive adhesive according to any one of claims 1 to 9, further comprising 0.001 to 10 parts by weight of a polyether-modified silicone compound with respect to 100 parts by weight of the (meth)acrylic polymer (A). Type polarizing plate. The weight-average molecular weight of the (meth)acrylic polymer (A) is 500,000 to 3,000,000, and the pressure-sensitive adhesive type polarizing plate according to claim 1. The pressure-sensitive adhesive type polarizing plate according to any one of claims 1 to 11, comprising an easy-adhesion layer between the polarizing plate and the pressure-sensitive adhesive layer. An image display device comprising at least one adhesive polarizing plate according to claim 1. It is a manufacturing method of the adhesive type polarizing plate in any one of Claims 1-12, Comprising:
A polarizing film of a continuous web made of a polyvinyl alcohol-based resin in which a dichroic material is oriented, wherein a laminate including a polyvinyl alcohol-based resin layer formed on a thermoplastic resin substrate is aerial auxiliary stretching and boric acid in water. A step of preparing a polarizer having the thickness of 10 μm or less, which is obtained by being stretched in a two-stage stretching step including stretching.
Only on one side of the polarizer, the step of obtaining the polarizing plate by bonding the transparent protective film, and
A method for producing a pressure-sensitive adhesive type polarizing plate, comprising the 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,
A method of transferring a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition to the polarizing plate, or
The method for producing an adhesive polarizing plate according to claim 14, which is a method of forming the adhesive layer by applying the adhesive composition to the polarizing plate.