KR101524612B1 - Antistatic pressure-sensitive adhesive composition and polarizer using the same - Google Patents

Abstract

The present invention relates to an antistatic pressure-sensitive adhesive composition and a polarizing plate using the same, and more particularly to a pressure-sensitive adhesive composition comprising a pressure-sensitive adhesive resin, a crosslinking agent and an antistatic agent, A pressure-sensitive adhesive composition capable of preventing antistatic agent from migrating to the surface and preventing precipitation, thereby preventing static electricity from being sufficiently suppressed while preventing deterioration of the physical properties of the pressure-sensitive adhesive itself such as tackiness and durability reliability and improving antistatic property; .

Antistatic property, pressure-sensitive adhesive, ionic solid, alkali metal salt

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antistatic pressure-sensitive adhesive composition and an antistatic pressure-

The present invention relates to a pressure-sensitive adhesive composition which can improve antistatic properties without deteriorating the physical properties of the pressure-sensitive adhesive itself such as tackiness and durability, and a polarizing plate using the pressure-sensitive adhesive composition.

In general, a liquid crystal display device (LCD) requires a liquid crystal cell including a liquid crystal and a polarizing plate, and an appropriate adhesive layer or adhesive layer for bonding the liquid crystal cell and the polarizing plate must be used.

The polarizing plate may further include a polyvinyl alcohol (PVA) polarizer (or a polarizing film) that is stretched in a predetermined direction and in which an iodine compound or a dichroic polarizing material is adsorbed and oriented, and a polarizer And a polarizer protective film laminated thereon. Specifically, a polarizer protective film such as triacetyl cellulose (TAC) is provided on one side of the polarizer, a pressure sensitive adhesive layer and a release film which are formed on the protective film so as to be in contact with the liquid crystal cell, The polarizer protective film and the base film are composed of a multilayer film having a surface protective film on which a pressure-sensitive adhesive layer is laminated.

In the process of adhering the polarizing plate having such a structure to the liquid crystal cell, the release film is peeled off from the pressure-sensitive adhesive layer, and when the surface protective film plays a role in the post-process, it is also peeled off. Since the release film and the surface protection film are made of a plastic material having high electrical insulation, static electricity is generated when the release film and the surface protection film are peeled off.

The static electricity generated in this way causes a problem of contamination of the surface due to adsorption of foreign matter on the optical member, a problem of staining due to distortion of the alignment of the liquid crystal, and the like, and there is a fear of damaging the thin film transistor (TFT) line. Particularly, in recent years, as the size of a liquid crystal display panel has been enlarged, the size of a polarizing plate has also been enlarged in accordance with the enlargement of the size of the liquid crystal display panel, and as the speed of the process is increased, the amount of static electricity is further increased. Therefore, a strong countermeasure for solving the static electricity problem is urgently required.

In order to solve the problem of generation of static electricity as described above, a method of imparting antistatic property to a pressure-sensitive adhesive has been proposed. Specifically, there are a method of adding a substance having a conductive component such as a conductive metal powder or carbon particles to a pressure-sensitive adhesive, a method of adding an ionic or nonionic substance in the form of a surfactant, and the like. However, in order to impart antistatic properties, there is a problem in that transparency is lowered due to the use of an excessive amount of conductive metal powder or carbon particles. Surfactants are susceptible to humidity and the adhesive property is deteriorated due to the property of being transferred to the surface of the pressure- .

Japanese Patent Application Laid-Open No. 1993-140519 (published on Jun. 6, 1993) discloses a method of suppressing the generation of static electricity by adding ethylene oxide modified phthalic acid dioctyl plasticizer to the inside of the pressure sensitive adhesive to give flexibility. However, the above method has a problem of transferring to the surface of the polarizing plate, and it is difficult to suppress the static electricity generated at the initial stage.

Korean Patent Laid-Open Publication No. 2004-0030919 (published on April 9, 2004) discloses a method of preparing a pressure-sensitive adhesive by adding an organic salt and using the pressure-sensitive adhesive to produce a pressure-sensitive adhesive layer having a surface resistivity of 10 ¹³ Ω / . However, this method uses an excessive amount of an organic salt, resulting in problems of adhesion and durability.

Japanese Patent Laid-Open Publication No. 1994-128539 (published on May 5, 1994) discloses a method for imparting antistatic property by blending a polyether polyol and at least one alkali metal salt. However, this method is not suitable for crosslinking even when isocyanate is used And the hydrophilic property of the plasticizer added to the pressure-sensitive adhesive may cause surface migration and deteriorate the adhesive property.

Korean Patent Publication No. 2006-0049137 (published on May 18, 2006) discloses a method for further improving antistatic performance by adding an ester plasticizer having at least one ether bond to an alkali metal salt and a quaternary ammonium salt, The plasticizer bleed-out to the surface of the pressure-sensitive adhesive, resulting in poor durability.

Japanese Unexamined Patent Publication No. 2006-152235 (published on June 15, 2006) discloses a pressure-sensitive adhesive composition comprising an ionic liquid, an alkali metal salt, and a base polymer having a glass transition temperature (Tg) of 0 ° C or lower. However, in order to maintain the physical properties of the pressure-sensitive adhesive, there is a limit to the amount of the antistatic agent that can be added, so that it is difficult to give sufficient antistatic property.

The present invention relates to an antistatic pressure-sensitive adhesive which does not cause a problem in endurance reliability, and which can sufficiently solve the problem of static electricity, even though a small amount of an antistatic agent is added in order to exhibit a high antistatic property required for a polarizing plate when applied to a liquid crystal display And to provide a composition.

Another object of the present invention is to provide a polarizing plate in which a pressure-sensitive adhesive layer composed of the antistatic pressure-sensitive adhesive composition is laminated.

It is another object of the present invention to provide a liquid crystal display device provided with the polarizer.

In order to achieve the above object, the present invention provides an antistatic pressure-sensitive adhesive composition comprising a pressure-sensitive adhesive resin, a crosslinking agent and an antistatic agent, wherein the antistatic agent is an ionic solid and an alkali metal salt which are solid at 25 ° C.

The present invention also provides a polarizing plate in which a pressure-sensitive adhesive layer composed of the antistatic pressure-sensitive adhesive composition is laminated.

The present invention also provides a liquid crystal display provided with the polarizer.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a pressure-sensitive adhesive composition which prevents migration of an antistatic agent to the surface and prevents precipitation of the antistatic agent, thereby preventing the occurrence of static electricity, , A polarizing plate using the same, and a liquid crystal display device.

The present invention relates to a pressure-sensitive adhesive composition which can improve antistatic properties without deteriorating the physical properties of the pressure-sensitive adhesive itself such as tackiness and durability, and a polarizing plate using the pressure-sensitive adhesive composition.

Hereinafter, the present invention will be described in detail.

The antistatic pressure-sensitive adhesive composition of the present invention is characterized by containing an ionic solid, which is a solid state salt at 25 ° C, and an alkali metal salt together as a pressure-sensitive adhesive resin, a crosslinking agent and an antistatic agent.

The pressure-sensitive adhesive resin may be an acrylic copolymer, a natural rubber, a styrene-isoprene-styrene (SIS) block copolymer, a styrene-butadiene-styrene (SBS) block copolymer, a styrene-ethylene butylene- It is possible to use ordinary polymers such as butadiene rubber, polybutadiene, polyisoprene, polyisobutylene, butyl rubber, chloroprene rubber and silicone rubber, and a (meth) acrylic copolymer can be preferably used.

As the (meth) acrylic copolymer, a copolymer of a (meth) acrylate monomer having an alkyl group of 1 to 14 carbon atoms and a monomer having a crosslinkable functional group can be used. Here, (meth) acrylate means both acrylate and methacrylate.

Specific examples of the (meth) acrylate monomers having 1 to 14 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, s- (Meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) acrylate, n-decyl (meth) acrylate, n-decyl (meth) acrylate, isononyl ) Acrylate, and n-tetradecyl (meth) acrylate. (Meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, (Meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (Meth) acrylate monomer in which the alkyl group of the alkyl group has 6 to 14 carbon atoms is preferably used because the adhesion to the adherend is controlled to be low and the re-peeling property is excellent.

The (meth) acrylate monomer having 1 to 14 carbon atoms is preferably contained in an amount of 50 to 99% by weight based on the total monomer content (100% by weight) used in the production of the (meth) acrylic copolymer.

The monomer having a crosslinkable functional group reacts with a crosslinking agent to give a cohesive force or a cohesive strength by chemical bonding so that the cohesive force of the pressure sensitive adhesive does not break under high temperature or high humidity conditions. For example, the monomer having a sulfonic acid group- , An amino group-containing monomer, an imide group-containing monomer, an epoxy group-containing monomer, an ether group-containing monomer, a carboxyl group-containing monomer, a carboxyl group-containing monomer, a cyano group-containing monomer, a vinyl ester, an aromatic vinyl compound, These may be used alone or in combination of two or more.

Examples of the sulfonic acid group-containing monomer include styrene sulfonic acid, allylsulfonic acid, 2- (meth) acrylamido-2-methylpropanesulfonic acid, (meth) acrylamidopropanesulfonic acid, sulfopropyl (meth) Acryloyloxynaphthalenesulfonic acid, sodium vinylsulfonate, and the like.

As the phosphate group-containing monomer, 2-hydroxyethyl acryloyl phosphate can be mentioned.

Examples of the cyano group-containing monomer include (meth) acrylonitrile.

Examples of the vinyl esters include vinyl acetate, vinyl propionate, and vinyl laurate.

Examples of the aromatic vinyl compound include styrene, chlorostyrene, chloromethylstyrene,? -Methylstyrene, and other substituted styrenes.

Examples of the carboxy group-containing monomer include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid and isocrotonic acid.

Examples of the acid anhydride-containing monomer include maleic anhydride, itaconic anhydride, and acid anhydrides thereof.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (Meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) (Meth) acrylamide, vinyl alcohol, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether and the like.

Examples of the amide group-containing monomer include (meth) acrylamide, diethylacrylamide, N-vinylpyrrolidone, N, N-dimethyl (meth) acrylamide, N, N'-methylenebisacrylamide, N, N-dimethylaminopropyl (meth) acrylamide, diacetone acrylamide and the like.

Examples of the amino group-containing monomer include aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, (meth) acryloylmorpholine, .

Examples of the imide group-containing monomer include cyclohexylmaleimide, isopropylmaleimide, N-cyclohexylmaleimide and itaconimide.

Examples of the epoxy group-containing monomer include glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, and allyl glycidyl ether.

Examples of the ether group-containing monomer include 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, phenoxyethyl And morpholine.

The monomer having a crosslinkable functional group is preferably contained in an amount of 1 to 50% by weight based on the total monomer content (100% by weight) used in the production of the (meth) acrylic copolymer.

The acrylic copolymer having the above components may be prepared by a conventional method such as a solution polymerization method, a photopolymerization method, a bulk polymerization method, a suspension polymerization method and an emulsion polymerization method, and is preferably prepared by a solution polymerization method.

The acrylic copolymer generally has a weight average molecular weight (in terms of polystyrene) measured by Gel Permeation Chromatography (GPC) of usually 50,000 to 2,000,000, preferably 100,000 to 1,800,000, more preferably 500,000 to 1,500,000 to be.

The crosslinking agent may be an isocyanate compound, an epoxy compound, a melamine resin, an aziridine compound, or the like, and preferably an isocyanate compound or an epoxy compound may be used. . These may be used alone or in combination of two or more.

Examples of the isocyanate compound include tolylene diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, 2,4-diphenylmethane diisocyanate, 4,4-diphenylmethane diisocyanate, isophorone diisocyanate, tetramethyl xylene diisocyanate , Naphthalene diisocyanate, and the like.

Examples of the epoxy compound include ethylene glycol diglycidyl ether, triglycidyl ether, trimethylolpropane triglycidyl ether, N, N, N ', N'-tetraglycidyldiamine, glycerin diglycidyl ether, , 3-bis (N, N-diglycidylaminomethyl) cyclohexane, and the like.

Examples of the melamine resin include hexamethylol melamine.

Examples of the aziridine compound include N, N'-toluene-2,4-bis (1-aziridinecarboxamide), N, N'-diphenylmethane-4,4'- Id), triethylene melamine, bisisopropanoyl-1- (2-methyl aziridine), and tri-1-aziridinyl phosphine oxide.

The crosslinking agent is preferably contained in an amount of 0.01 to 15 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive resin (based on the solid content). If the content is less than 0.01 part by weight, the adhesive force or the cohesive force of the pressure-sensitive adhesive is not good. If the content exceeds 15 parts by weight, the compatibility may decrease and surface migration may occur.

As the crosslinking agent, an ultraviolet curable polyfunctional (meth) acrylate monomer may be used. Specific examples include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) (Meth) acrylate, diacryloyloxyethyl isocyanurate, di (methoxy) acrylate, di (methoxy) acrylate, ) Diacrylate such as dimethylolcyclohexane diacrylate, dimethyoledicyclopentane diacrylate, ethylene oxide modified hexahydrophthalic acid diacrylate, tricyclodecane dimethanol acrylate, neopentyl glycol modified trimethylolpropane diacrylate and adamantanediacrylate Monomer; (Meth) acrylate such as trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri Trifunctional monomers such as tri (meth) acrylate and tris (acryloxyethyl) isocyanurate; Tetrafunctional monomers such as diglycerin tetra (meth) acrylate and pentaerythritol tetra (meth) acrylate; Pentafunctional monomers such as propionic acid-modified dipentaerythritol penta (meth) acrylate; And hexafunctional monomers such as caprolactone-modified dipentaerythritol hexa (meth) acrylate. These may be used alone or in combination of two or more.

It is preferable that the ultraviolet curable multi-functional (meth) acrylate monomer is contained in an amount of 0.1 to 30 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive resin (based on the solid content).

The ultraviolet curable polyfunctional (meth) acrylate monomer may be used in combination with a photopolymerization initiator that generates radicals or cations by irradiation with ultraviolet light.

Specific examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- hydroxycyclohexyl phenyl ketone , 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan- ) Ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methyl anthraquinone, 2-ethyl anthraquinone, 2- Anthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethylketal, acetophenone dimethyl Ketal, p-dimethylaminobenzoic acid S LE and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and the like, and these may be used alone or in combination of two or more. The photopolymerization initiator may be contained in an amount of usually 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive resin (based on the solid content).

The antistatic agent preferably contains an ionic solid and an alkali metal salt together.

The ionic solid used as a main component of the antistatic agent of the present invention is a salt which is formed by combining ions of an organic cation and an anion, which are cations containing at least one carbon atom in the molecule, and is in a solid state at room temperature (25 캜). In general, salts of an ionic liquid and an ionic solid may be formed by combining ions of an organic cation and an anion. In the present invention, however, only salts which are solid at room temperature are included.

Examples of the organic cation of the ionic solid include a pyridinium cation, a piperidinium cation, a pyrrolidinium cation, a cation having a pyrrolene skeleton, a cation having a pyrrole skeleton, an imidazolium cation, a tetrahydropyrimidinium cation, Pyrazolinium cations, pyrazolinium cations, tetraalkylammonium cations, trialkylsulfonium cations, tetraalkylphosphonium cations, and cations in which some of these alkyl groups are substituted with an alkenyl group, alkoxyl group or epoxy group, etc. . Of these, pyridinium, pyrrolidinium or tetraalkylammonium cations are preferred.

Specific examples of the pyridinium cations include 1-ethylpyridinium, 1-butylpyridinium, 1-hexylpyridinium, 1-butyl-3-methylpyridinium, Hexyl-3-methylpyridinium, 1-butyl-3,4-dimethylpyridinium, and 1-octyl-4-methylpyridinium cation.

Specific examples of the pyrrolidinium cation include 1,1-dimethylpyrrolidinium, 1-ethyl-1-methylpyrrolidinium and 1-methyl-1-propylpyrrolidinium cation.

Specific examples of the cation having the pyrroline skeleton include 2-methyl-1-pyrroline cation, and specific examples of the cation having the pyrrole skeleton include 1-ethyl-2-phenylindole, 1,2-dimethylindole , 1-ethylcarbazole cation, and the like.

Specific examples of the imidazolium cations include 1,3-dimethylimidazolium, 1,3-diethylimidazolium, 1-ethyl-3-methylimidazolium, 1-butyl- 3-methylimidazolium, 1-undecyl-3-methylimidazolium, 1-tetradecyl Methylimidazolium, 1, 2-dimethyl-3-propylimidazolium, 1-ethyl-2,3-dimethylimidazolium, 1-butyl- -2,3-dimethylimidazolium cation, and the like.

Specific examples of the tetrahydropyrimidinium cations include 1,3-dimethyl-1,4,5,6-tetrahydropyrimidinium, 1,2,3-trimethyl-1,4,5,6-tetrahydro Pyrimidinium, 1,2,3,4-tetramethyl-1,4,5,6-tetrahydropyrimidinium, 1,2,3,5-tetramethyl-1,4,5,6-tetrahydro Pyrimidinium cation and the like.

Specific examples of the dihydropyrimidinium cation include 1,3-dimethyl-1,4-dihydropyrimidinium, 1,3-dimethyl-1,6-dihydropyrimidinium, 1,2,3- 1,4-dihydropyrimidinium, 1,2,3-trimethyl-1,6-dihydropyrimidinium, 1,2,3,4-tetramethyl-1,4-dihydropyrimidinium , 1,2,3,4-tetramethyl-1,6-dihydropyrimidinium cation, and the like.

Specific examples of the pyrazolium cations include 1-methylpyrazolium and 3-methylpyrazolium cations. Specific examples of the pyrazolinium cations include 1-ethyl-2-methylpyrazolinium cations .

Specific examples of the tetraalkylammonium cations include tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, tetrapentylammonium, tetrahexylammonium, tetraheptylammonium, triethylmethylammonium, tributylethylammonium, trimethyldecyl For example, ammonium, trioctylmethylammonium, tripentylbutylammonium, trihexylmethylammonium, trihexylpentylammonium, triheptylmethylammonium, tripentylbutylammonium, triheptylhexylammonium, dimethyldihexylammonium, dipropyldihexylammonium, heptyldimethyl N, N-dimethyl-N-ethyl-N-propylammonium, N, N-diethyl-N-methyl- N- (2-methoxyethyl) ammonium, glycidyltrimethylammonium, Dimethyl-N-ethyl-N-butylammonium, N, N-dimethyl-N-ethyl-N-pentylammonium, N, N-heptylammonium, N, N-dimethyl-N-ethyl-N-nonylammonium, N, Propyl-N-butylammonium, N, N-dimethyl-N-propyl-N-pentylammonium, N, N, N-dimethyl-N-butyl-N-hexylammonium, N, N-dimethyl- N, N-diethyl-N-methyl-N-heptylammonium, N, N-diethyl- , N-diethyl-N-propyl-N-pentylammonium, triethylmethylammonium, triethylpropylammonium, triethylpentylammonium, triethylheptylammonium, N, N, N-dipropyl-N-methyl-N-pentylammonium, N, N-dipropyl- N-dibutyl-N-methyl-N-hexylammonium, trioctylmethylammonium, N-methyl-N-ethyl-N-propyl-N-pentylammonium cation and the like.

Specific examples of the trialkylsulfonium cation include trimethylsulfonium, triethylsulfonium, tributylsulfonium, trihexylsulfonium, diethylmethylsulfonium, dibutylethylsulfonium, dimethyldysulfonylium cations and the like. .

Specific examples of the tetraalkylphosphonium cations include tetramethylphosphonium, tetraethylphosphonium, tetrabutylphosphonium, tetrapentylphosphonium, tetrahexylphosphonium, tetraheptylphosphonium, tetraoctylphosphonium, triethylmethylphosphonium, Phosphonium, tributylethylphosphonium, trimethyldecylphosphonium cation, and the like.

The ionic anions of the solid is OTf ^- (methanesulfonate trifluoroacetate), OTs ^- (toluene-4-sulfonate), OMs ^{- (methanesulfonate), Cl -, Br -,} I -, AlCl 4 - ^{_{, Al 2 Cl 7 -, BF}} 4 -, PF 6 -, ClO 4 -, NO 3 -, 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 -, AsF 6 -, SbF 6 -, NbF 6 -, TaF 6 -, F (HF) n -, (CN) 2 n -, C 4 F 9 SO ₃ ^- , (C ₂ F ₅ SO ₂ ) ₂ N ^- , C ₃ F ₇ COO ^- or (CF ₃ SO ₂ ) (CF ₃ CO) N ^- . Of these, BF ₄ ^- or PF ₆ ^- is preferable in terms of antistatic performance and ease of production into an ionic solid.

Preferable examples of the ionic solid include 1-butyl-4-methylpyridinium hexafluorophosphate represented by the following Chemical Formulas 1 to 5, hexylpyridinium hexafluorophosphate, 1-octyl-4-methylpyridinium At least one selected from the group consisting of hexafluorophosphate, 1-methyl-1-butylpyrrolidinium hexafluorophosphate and methyl-trioctylammonium hexafluorophosphate.

When the above-mentioned ionic solid is included in a composition having poor compatibility with the pressure-sensitive adhesive resin, the ionic solid tends to be precipitated when added over a certain amount. Therefore, in order to obtain a high antistatic property, it is preferable to use it in combination with an alkali metal salt.

The alkali metal salt is used in combination with an ionic solid which is a main component of an antistatic agent to prevent the ionic solid from precipitating and to improve the antistatic property.

The alkali metal salt may be a lithium salt, a sodium salt or a potassium salt as a salt by combining ion of cation and anion. Specific examples include, lithium iodide (LiI), lithium perchlorate (LiClO _4), sodium perchlorate (NaClO _4), potassium perchlorate (KClO _4), lithium hexafluoro roal Senate (LiAsF _6), lithium tetrafluoroborate (LiBF ₄ ), Lithium hexafluorophosphate (LiPF ₆ ), sodium hexafluorophosphate (NaPF ₆ ), lithium trifluoromethanesulfonate (LiCF ₃ SO ₃ ), bis (trifluoromethanesulfonyl) imide lithium (LiN CF ₃ SO _{2) 2),} tris (trifluoromethane sulfonyl) methide lithium _{(LiC (CF 3 SO 2)} 3), bis (sulfonyl fluorophenyl) imide potassium _{(KaN (FSO 2) 2)} , Lithium bis (fluorosulfonyl) imide sodium (NaN (FSO ₂ ) ₂ ), bis (fluorosulfonyl) imide lithium (LiN (FSO ₂ ) ₂ ) and the like. And the anion is preferably a bis (fluorosulfonyl) imide salt or a hexafluorophosphate salt. More preferably, lithium iodide (LiI), lithium perchlorate (LiClO ₄ ), or bis (fluorosulfonyl) imide potassium (KaN (FSO ₂ ) ₂ ) may be used alone or in combination of two or more. .

When the ionic solid and the alkali metal salt are used together, the total amount of the antistatic agent can be reduced, and more excellent antistatic property can be imparted while maintaining the physical properties of the pressure-sensitive adhesive itself. The ionic solid is preferably contained in an amount of 0.1 to 10 parts by weight, more preferably 0.5 to 8 parts by weight, and most preferably 1 to 5 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive resin (based on the solid content). When the content is less than 0.1 part by weight, the surface conductivity may be weakened, and when it is more than 10 parts by weight, the surface conductivity may be improved but the adhesive property may be deteriorated.

The amount of the alkali metal salt is preferably 0.01 to 3 parts by weight, more preferably 0.05 to 1 part by weight, and most preferably 0.1 to 0.5 part by weight based on 100 parts by weight of the pressure-sensitive adhesive resin (based on the solid content). The alkali metal salt is a material which exhibits ionic dissociation by ion dissociation. If the content of the alkali metal salt is too small, the antistatic property is poor. If the amount of the alkali metal salt is excessive, the increase of antistatic property becomes dull and the durability of the pressure- And may cause deterioration. Therefore, it is preferable that the content is within the above range.

The antistatic pressure-sensitive adhesive composition containing the above-mentioned components may further contain a silane coupling agent as needed in order to improve adhesion with the liquid crystal cell or substrate.

Specific examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane , 3-mercaptopropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, and 3-chloropropyltrimethoxysilane. These may be used alone or in combination of two or more. The silane coupling agent may be contained in an amount of 0.005 to 5 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive resin (based on the solid content).

The pressure-sensitive adhesive composition may further contain additives such as a tackifier resin, an antioxidant, a corrosion inhibitor, a leveling agent, a surface lubricant, a dye, a pigment, an antifoaming agent, a filler, and the like to control the adhesion, cohesion, viscosity, , A plasticizer, or a light stabilizer.

The antistatic pressure-sensitive adhesive composition may be used as a pressure-sensitive adhesive for a polarizing plate. It can be used not only as a surface protective film, a protective film, a reflective sheet, a structural adhesive sheet, a photographic adhesive sheet, a lane marking adhesive sheet, an optical adhesive product, .

The polarizing plate of the present invention is characterized in that an antistatic pressure-sensitive adhesive layer composed of the above-mentioned antistatic pressure-sensitive adhesive composition is laminated.

The polarizing plate includes a polarizer (or a polarizing film), a polarizer protective film for protecting the polarizer, a pressure-sensitive adhesive layer to be in contact with the liquid crystal cell, and a release film are sequentially laminated on one side of the polarizer, And a polarizer protective film is provided on the other surface of the polarizer.

As the polarizer, a film made of a polyvinyl alcohol resin and having a dichroic dye adsorbed and oriented can be used. As the polyvinyl alcohol resin constituting the polarizer, a copolymer of vinyl acetate, which is a homopolymer of vinyl acetate, vinyl acetate and another monomer copolymerizable therewith, and the like can be used. Examples of other monomers copolymerizable with vinyl acetate at this time include unsaturated carboxylic acids, unsaturated sulfonic acids, olefins, vinyl ethers, and acrylamides having an ammonium group. The thickness of the polarizer is not particularly limited, and can be made in a usual thickness.

The polarizer protective film is preferably excellent in transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, and the like, and examples thereof include polyester films such as polyethylene terephthalate, polyethylene isophthalate and polybutylene terephthalate; Cellulose-based films such as diacetylcellulose and triacetylcellulose; Polycarbonate film; Acrylic films such as polymethyl (meth) acrylate and polyethyl (meth) acrylate; Styrene-based films such as polystyrene and acrylonitrile-styrene copolymer; Polyolefin-based films such as polyethylene, polypropylene, cyclo-based or norbornene-based polyolefin-based films, and ethylene propylene copolymers; Polyimide-based films; Polyethersulfone-based films; A sulfone-based film, and the like, and their thickness is not particularly limited.

The release film is a film for protecting the antistatic pressure-sensitive adhesive layer, and the kind thereof is not particularly limited as long as it is a film ordinarily used in the art. Specific examples thereof include polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene- A polyolefin-based film such as an ethylene-vinyl alcohol copolymer; Polyester films such as polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate; Polyamide-based films such as polyacrylate, polystyrene, nylon 6, and partially aromatic polyamide; Polyvinyl chloride films; Polyvinylidene chloride films; Or a polycarbonate film. These may be appropriately subjected to a release treatment by a silicone system, a fluorine system, a silica powder or the like.

The method of laminating the antistatic pressure-sensitive adhesive layer on the polarizing plate is not particularly limited as long as it is a method commonly used in the art. For example, the pressure-sensitive adhesive composition may be applied on a polarizer protective film by a method such as a fluidized casting method, a bar coater, an air knife, a gravure, a reverse roll, a kiss roll, for example, a spray or a blade method, followed by drying and coating with a polarizing plate. Further, a pressure-sensitive adhesive layer was formed on the silicone-coated release film by the same application method as described above to produce a pressure-sensitive adhesive sheet, which was laminated with silicone-coated release films having different peeling forces using a roll- And then sticking to a polarizing plate. When a UV-curable multi-functional (meth) acrylate monomer is used as the crosslinking agent, the release film may be irradiated with ultraviolet rays after the polarizing plate is laminated, or a silicone-coated release film having a different peeling force using a roll- And then irradiating ultraviolet rays after lamination.

The thickness of the antistatic pressure-sensitive adhesive layer can be adjusted according to the adhesive force, and is preferably 3 to 100 탆, more preferably 10 to 100 탆.

The polarizing plate can be applied to all liquid crystal display devices.

The liquid crystal display of the present invention is characterized in that a polarizing plate in which the antistatic pressure-sensitive adhesive layer is laminated on at least one surface of a liquid crystal cell is provided.

In the present invention, since the liquid crystal display device is well known to those skilled in the art, a detailed description thereof will be omitted.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims.

In the following Production Examples, Examples and Comparative Examples, '%' and 'part' indicating the content are based on weight unless otherwise specified.

Manufacturing example  1. Preparation of Acrylic Copolymer A

A four neck jacket reactor 1L was equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introducing tube. The reactor was charged with nitrogen gas and replaced with 164 parts of ethyl acetate, n- 126 parts of butyl acrylate, 0.5 part of acrylic acid and 1.3 parts of 2-hydroxyethyl acrylate were charged, and the external temperature of the reactor was raised to 50 占 폚. Then, a solution in which 0.14 part of 2,2'-azobisisobutyronitrile (AIBN) was completely dissolved in 10 parts of ethyl acetate was added dropwise to the reactor. The jacket was allowed to react for an additional 5 hours while maintaining the external temperature at 50 DEG C, and then 90 parts of ethyl acetate was slowly added dropwise through the dropping funnel for 1 hour. After further stirring at the same temperature for 6 hours, 304 parts of ethyl acetate was added, and the mixture was further stirred for 2 hours to obtain a final acrylic copolymer A. [ The prepared acrylic copolymer A had a solid content of 20% and a weight average molecular weight (in terms of polystyrene) of about 1,500,000 as determined by GPC.

Manufacturing example  2. Preparation of Acrylic Copolymer B

Except that 126 parts of n-butyl acrylate, 1.1 parts of acrylic acid, 2.7 parts of 2-hydroxyethyl acrylate, 36.6 parts of methyl acrylate, 14.6 parts of 2-phenoxyethyl acrylate and 1.8 parts of methoxyethyl acrylate were used as monomers Was used in the same manner as in Preparation Example 1 to obtain an acrylic copolymer B. [ The prepared acrylic copolymer B had a solid content of 20% and a weight average molecular weight (in terms of polystyrene) of about 1,500,000 as measured by the GPC method.

Example  One

100 parts of the acrylic copolymer A (based on the solid content) prepared in Preparation Example 1, 0.5 part of trimethylolpropane-modified tolylene diisocyanate (Coronate L, manufactured by Nippon Polyurethane Industry) as a crosslinking agent, 0.5 part of 3-glycidoxy 0.5 part of propyltrimethoxysilane (KBM403, Shin-Etsu), 0.8 part of 1-octyl-4-methylpyridinium hexafluorophosphate (IL-P18-2, manufactured by Nippon Kogaku Kagaku) as an antistatic agent and 0.1 part of KN (FSO ₂ ) ₂ , which is an alkali metal salt, was added and diluted with ethyl acetate to an appropriate concentration to prepare a pressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition thus prepared was coated on a polyethylene terephthalate film (41 cm x 34 cm) coated with silicone release agent to a dry film thickness of 25 m and dried at 100 deg. C for 1 minute to form a pressure-sensitive adhesive layer. A conventional polarizing plate was laminated on the prepared pressure-sensitive adhesive layer and cured at room temperature for 7 days to prepare a plurality of polarizing plate adhesive sheets.

Example  2

Except that 0.8 part of methyl-trioctylammonium hexafluorophosphate (IL-A2-2, manufactured by Nihon Koen Chemical Co., Ltd.) as an ionic solid as an antistatic agent and 0.1 part of KN (FSO ₂ ) ₂ as an alkali metal salt were used as the antistatic agent 1. ≪ / RTI >

Example  3

Except that 3.0 parts of methyl-trioctylammonium hexafluorophosphate (IL-A2-2, manufactured by Nippon Kogaku Kagaku) as an ionic solid as an antistatic agent and 0.1 part of KN (FSO ₂ ) ₂ as an alkali metal salt were used. 1. ≪ / RTI >

Example  4 to 13, Comparative Example  1 to 5

The same procedures as in Example 1 were carried out except that the components and the contents as shown in the following Table 1 were used.

The components and content of the antistatic pressure-sensitive adhesive composition prepared in the above Examples and Comparative Examples are shown in Table 1 below. Here, the content of each component represents parts by weight.

division
Acrylic
Copolymer Cross-linking agent Silane
Coupling agent Antistatic agent Ionic solid Alkali metal salt Kinds content COR-L KBM-403 IL-P18-2 IL-A2-2 LiI LiClO ₄ KN (FSO ₂ ) ₂ Example 1 A 100 0.5 0.5 0.8 - - - 0.1 Example 2 A 100 0.5 0.5 - 0.8 - - 0.1 Example 3 A 100 0.5 0.5 - 3 - - 0.1 Example 4 A 100 0.5 0.5 3 - 0.1 - - Example 5 A 100 0.5 0.5 3 - 0.5 - - Example 6 A 100 0.5 0.5 3 - - 0.1 - Example 7 A 100 0.5 0.5 3 - - 0.5 - Example 8 A 100 0.5 0.5 3 - - - 0.1 Example 9 A 100 0.5 0.5 3 - - - 0.5 Example 10 B 100 0.5 0.5 0.8 - - - 0.1 Example 11 B 100 0.5 0.5 3 - - - 0.1 Example 12 B 100 0.5 0.5 5 - - - 0.1 Example 13 B 100 0.5 0.5 7 - - - 0.1 Comparative Example 1 A 100 0.5 0.5 4 - - - - Comparative Example 2 A 100 0.5 0.5 - 4 - - - Comparative Example 3 B 100 0.5 0.5 8 - - - - Comparative Example 4 B 100 0.5 0.5 - 8 - - - Comparative Example 5 B 100 0.5 0.5 10 - - - -

Test Example

The physical properties of the polarizing plate-adhered sheets prepared in the Examples and Comparative Examples were measured by the following methods, and the results are shown in Table 2 below.

* Surface resistivity (Ω / □)

- Meter: Surface Resistance Meter (MCP-HT450 / MITSUBISHI CHEMICAL)

Probe (URS, UR100), Probe Checker (URS, UR 100)

- Measurement method: The PET film was peeled off, and three points on the surface of the pressure-sensitive adhesive layer were measured ten times each, and the average value was measured.

* Endurance reliability

The prepared polarizer-adhered sheet was cut so as to have a size of 300 mm x 220 mm, and then it was bonded to a glass of Corning # 1737 to prepare a specimen. The prepared specimens were treated in an autoclave at 5 atm and 50 ° C for 20 minutes and then placed in an oven at 60 ° C and 90% relative humidity for 300 hours. The peeling phenomenon such as peeling and exfoliation of the specimen left on the surface of the specimen and the occurrence of bubbles were visually confirmed and evaluated based on the following criteria.

○: No peeling and no bubbles (Good)

△: Peeling phenomenon and generation of bubbles are somewhat (usually)

X: Peeling phenomenon and generation of bubbles are high (poor)

* Whether surface deposition of antistatic agent

After peeling off the PET film (heavy-weight release film) of the polarizing plate adhesive sheet having completed the curing, it was visually observed that the foreign matter was precipitated on the surface of the pressure-sensitive adhesive layer, and the precipitated foreign matter sample was sampled and confirmed with an optical microscope.

division Surface resistivity (Ω / □) Antistatic agent precipitation Endurance reliability Example 1 1.20E + 11 none ○ Example 2 4.42E + 11 none ○ Example 3 6.30E + 10 none △ Example 4 1.21E + 10 none ○ Example 5 5.80E + 09 none ○ Example 6 1.10E + 10 none ○ Example 7 8.42E + 09 none ○ Example 8 1.10E + 10 none ○ Example 9 3.60E + 09 none ○ Example 10 1.18E + 11 none ○ Example 11 1.34E + 10 none ○ Example 12 5.35E + 09 none ○ Example 13 1.10E + 09 none △ Comparative Example 1 2.50E + 10 Precipitation × Comparative Example 2 6.24E + 10 Precipitation × Comparative Example 3 3.10E + 09 Precipitation × Comparative Example 4 5.92E + 09 Precipitation × Comparative Example 5 1.60E + 09 Precipitation ×

As shown in Table 2, the polarizing plate adhesive sheets of Examples 1 to 13, in which an ionic solid and an alkali metal salt were both included as an antistatic agent in accordance with the present invention, did not deposit on the surface of the antistatic agent, And it was confirmed that the property was excellent. Particularly, when 3 to 5 parts by weight of an ionic solid and 0.1 to 0.5 parts by weight of an alkali metal salt are included together (Examples 3-9 and 11-12), a small amount of an antistatic agent is contained, While still having excellent antistatic properties. In Example 13, even when a smaller amount of the antistatic agent was used as compared with Comparative Example 5 containing 10 parts by weight of the ionic solid, the ionic solid and the alkali metal salt were used together, And the reliability of endurance was not significantly degraded.

On the other hand, in Comparative Examples 1 to 5 including the ionic solid alone, it was confirmed that the antistatic property was obtained, but the ionic solid precipitated on the surface and the durability reliability was greatly lowered. Particularly, in the case of using the acrylic copolymer B, in order to obtain an excellent antistatic property, when an acrylic copolymer B having an ionic solid content of 4 parts by weight or more and a relatively high content of a crosslinkable monomer is used, If the ionic solid is contained in an amount of 8 parts by weight or more, the endurance reliability can not be maintained.

Claims (7)

A pressure-sensitive adhesive resin, a crosslinking agent, and an antistatic agent, Wherein the antistatic agent comprises 0.1 to 10 parts by weight of an ionic solid and 0.01 to 1 part by weight of an alkali metal salt with respect to 100 parts by weight of the pressure-sensitive adhesive resin at 25 占 폚. The method of claim 1, wherein the ionic solid is selected from the group consisting of 1-butyl-4-methylpyridinium hexafluorophosphate, hexylpyridinium hexafluorophosphate, 1-octyl- Methyl-1-butylpyrrolidinium hexafluorophosphate, and methyl-trioctylammonium hexafluorophosphate. The antistatic pressure- The lithium secondary battery according to claim 1, wherein the alkali metal salt is at least one selected from the group consisting of lithium iodide (LiI), lithium perchlorate (LiClO ₄ ), sodium perchlorate (NaClO ₄ ), potassium perchlorate (KClO ₄ ), lithium hexafluoroarsenate (LiAsF ₆ ) (LiBF ₄ ), lithium hexafluorophosphate (LiPF ₆ ), sodium hexafluorophosphate (NaPF ₆ ), lithium trifluoromethanesulfonate (LiCF ₃ SO ₃ ), bis (trifluoromethanesulfonyl) imide lithium _{(LiN (CF 3 SO 2)} 2), tris (trifluoromethane sulfonyl) methide lithium _{(LiC (CF 3 SO 2)} 3), bis (sulfonyl fluorophenyl) imide potassium (KaN ( FSO _{2) 2),} bis (sulfonyl fluorophenyl) imide sodium (NaN (FSO _{2) 2)} and bis (sulfonyl fluorophenyl) already one selected from the group consisting of de lithium (LiN (FSO _{2) 2)} By weight based on the total weight of the pressure-sensitive adhesive composition. delete The antistatic pressure-sensitive adhesive composition according to claim 1, wherein the ionic solid is contained in an amount of 1 to 5 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive resin (based on the solid content), and the alkali metal salt is contained in an amount of 0.1 to 0.5 parts by weight. A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer comprising an antistatic pressure-sensitive adhesive composition according to any one of claims 1 to 5. The liquid crystal display device according to claim 6, wherein at least one surface of the liquid crystal cell is provided with the polarizing plate.