KR20090120703A - Anti-static adhesive composition for polarizing plate, polarizing plate and surface protective film using the composition - Google Patents

Abstract

PURPOSE: An anti-static adhesive composition for a polarizing plate, and a polarizing plate and a surface protective film using the composition are provided to suppress static electricity and to improve antistatic property while not degrading adhesive property and endurance reliability. CONSTITUTION: An anti-static adhesive composition for a polarizing plate comprises an adhesive resin, a cross-linking agent, and an antistatic agent. The anti-static agent is a conductive polymer polymerized in the presence of an organic solvent dispersible dopant. The conductive polymer is at least one selected from the group consisting of polythiophene, polyacetylene, polyaniline, polypyrrole, polyphenylene and their derivative.

Description

Antistatic pressure-sensitive adhesive composition for polarizing plate, polarizing plate and surface protective film using the same {ANTI-STATIC ADHESIVE COMPOSITION FOR POLARIZING PLATE, POLARIZING PLATE AND SURFACE PROTECTIVE FILM USING THE COMPOSITION}

The present invention is a pressure-sensitive adhesive composition for a polarizing plate that can impart improved antistatic properties without any problem of compatibility between the conductive polymer and the pressure-sensitive adhesive resin without lowering the physical properties of the pressure-sensitive adhesive itself, such as adhesiveness and durability, polarizing plate using the same And a surface protective film.

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

In addition, the polarizing plate is stretched in a predetermined direction, the polyvinyl alcohol (PVA) polarizer (or 'polarizing film') and the iodine-based compound or dichroic polarizing material adsorbed and oriented to protect both sides of the polarizer And a polarizer protective film laminated for the purpose. Specifically, one side of the polarizer is provided with a polarizer protective film such as triacetyl cellulose (TAC), an adhesive layer and a release film to be affixed to the liquid crystal cell on the protective film, the other side of the polarizer The protective film and the base film is composed of a multilayer having a surface protection film laminated with an adhesive layer.

In the process of attaching the polarizing plate having such a structure to the liquid crystal cell, the release film is peeled off from the pressure-sensitive adhesive layer. Since the release film and the surface protective film are made of a plastic material, they have high electrical insulation properties and generate static electricity during peeling.

The static electricity generated in this way may cause foreign matter to be adsorbed on the optical member to contaminate the surface, staining due to distortion of the liquid crystal alignment, and may cause breakage of thin film transistor (TFT) lines. In particular, in recent years, as the size of the liquid crystal display panel increases, the size of the polarizing plate used in the manufacture of the liquid crystal display is also increased, and as the speed of the process increases, the amount of static electricity is further increased, thereby solving the problem.

In order to solve the static electricity generation problem as described above, a method for imparting antistatic property to the pressure-sensitive adhesive has been proposed. Specifically, a method of adding a substance having a conductive component such as conductive metal powder or carbon particles to the 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, an excessive amount of conductive metal powder or carbon particles must be used, which leads to a problem in that the transparency is lowered. The surfactant is susceptible to humidity and degrades adhesive properties due to migration to the surface of the adhesive. There is a problem.

Japanese Laid-Open Patent Publication No. 199-140519 (published on June 6, 1993) discloses a method of adding an ethylene oxide-modified dioctyl-based plasticizer to the inside of an adhesive to provide flexibility, thereby suppressing the generation of static electricity. However, the method has a problem that the transfer to the surface of the polarizing plate occurs, it is difficult to suppress the static electricity generated in the early stage.

Korean Patent Laid-Open Publication No. 2004-0030919 (published on Apr. 9, 2009) discloses a method for preparing a pressure-sensitive adhesive by adding an organic salt and using the same to prepare a pressure-sensitive adhesive layer having a surface specific resistance of 10 ¹³ Ω / □ or less. . However, this method has a problem of using an excessive amount of expensive organic salt.

Japanese Laid-Open Patent Publication No. 1994-128539 (published on April 10,199) discloses a method of imparting antistatic properties by blending a polyether polyol and at least one alkali metal salt, but this method has a crosslinking degree when the crosslinking agent is an isocyanate. In addition to affecting the hydrophilicity of the ethylene oxide, there was a problem in that the surface transition to reduce the adhesiveness.

On the other hand, a method of using a conductive polymer that can be controlled from the insulator to the conductor showing electrical conductivity through the doping process has been proposed as an antistatic agent.

Korean Patent No. 0728329 (2007.06.07.registration) discloses an adhesive film for surface protection having an antistatic adhesive layer formed by applying a coating liquid composed of a conductive polymer and an adhesive resin. However, the specific dispersion method for preparing the conductive polymer and the pressure-sensitive adhesive resin with poor compatibility is not described at all, and due to such compatibility problems, there are many difficulties in direct implementation.

Korean Patent Publication No. 2007-0111005 (Nov. 21, 2007) discloses an PDP pressure-sensitive adhesive composition comprising an antistatic agent solution, a crosslinking agent, and an adhesive resin solution composed of a conductive polymer and an organic solvent. However, in order to prepare the composition, the conductive polymer should be dispersed in a pressure-sensitive adhesive resin solution. For this purpose, a time for processing the conductive polymer in an organic solvent is required for 20 to 30 hours, so that the processability is low and the dispersibility of a suitable degree can be directly performed. There is a problem that is difficult to obtain (compatibility).

As described above, the conductive polymer should have a property of dissolving in the organic solvent for mixing with other components used in the pressure-sensitive adhesive composition for commercial use, but due to the strong interaction by the unlocalized double bonds in the organic solvent Its solubility is very low. Conventionally, a method of using a dopant substituted with phosphoric acid, carboxylic acid, or sulfonic acid functional group has been mainly used to increase the solubility of the conductive polymer. There was a problem in that the dopant is de-doped in the conductive polymer backbone under high temperature conditions when used for a long time.

In the present invention, even when a small amount of the antistatic agent is added without causing a problem of durability deterioration caused by adding a large amount of the antistatic agent to exhibit the high antistatic property required for the polarizing plate when applied to the liquid crystal display device It is an object of the present invention to provide an antistatic adhesive composition for a polarizing plate capable of sufficiently solving an electrostatic problem without any problem on compatibility between an antistatic agent and an adhesive resin without any problem in durability.

In addition, another object of the present invention is to provide a polarizing plate in which a pressure-sensitive adhesive layer made of the antistatic pressure-sensitive adhesive composition is laminated.

In another aspect, the present invention is to provide a surface protective film laminated pressure-sensitive adhesive layer made of the antistatic pressure-sensitive adhesive composition.

In order to achieve the above object, the present invention is an adhesive composition comprising an adhesive resin, a crosslinking agent and an antistatic agent, wherein the antistatic agent is an antistatic property for a polarizing plate, characterized in that the conductive polymer polymerized in the presence of an organic solvent dispersible dopant. It provides an adhesive composition.

In another aspect, the present invention provides a polarizing plate laminated with an antistatic adhesive layer made of the antistatic adhesive composition.

In another aspect, the present invention provides an antistatic surface protective film made of the antistatic adhesive composition.

According to the present invention, there is no problem of compatibility between the conductive polymer, which is an antistatic agent, and the adhesive resin, without lowering the physical properties of the adhesive itself, such as adhesiveness, durability, reliability, and the like. Can be improved.

The present invention is a pressure-sensitive adhesive composition, polarizing plate and surface using the same without impairing the physical properties of the pressure-sensitive adhesive itself, such as adhesiveness, durability and reliability at the same time there is no problem of compatibility between the conductive polymer and the adhesive resin It relates to a protective film.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The antistatic adhesive composition for polarizing plates of the present invention is an adhesive composition comprising an adhesive resin, a crosslinking agent, and an antistatic agent, wherein the antistatic agent is a conductive polymer polymerized in the presence of an organic solvent dispersible dopant.

The adhesive resin is acrylic copolymer, natural rubber, styrene-isoprene-styrene (SIS) block copolymer, styrene-butadiene-styrene (SBS) block copolymer, styrene-ethylenebutylene-styrene (SEBS) block copolymer, styrene- Ordinary polymers, such as butadiene rubber, polybutadiene, polyisoprene, polyisobutylene, butyl rubber, chloroprene rubber and silicone rubber, can be used, and preferably acrylic copolymers can be used.

As an acryl-type copolymer, the copolymer of the monomer which has a crosslinkable functional group with the (meth) acrylate monomer of C1-C14 of an alkyl group can be used. In this case, (meth) acrylate means both acrylate and methacrylate.

Specific examples of the (meth) acrylate monomer having 1 to 14 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, s-butyl (meth) acrylate, t -Butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth ) Acrylate, n- tetradecyl (meth) acrylate, n- tetradecyl (meth) acrylate, etc. are mentioned. Among these, when used for a surface protection film, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) Acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, n -The use of (meth) acrylate monomers having 6 to 14 carbon atoms in alkyl groups such as tetradecyl (meth) acrylate and n-tetradecyl (meth) acrylate is used to control the adhesion to the adherend to reduce re-peelability. It is preferable at the point which is excellent.

The (meth) acrylate monomer having 1 to 14 carbon atoms is preferably included in 50 to 99% by weight relative to the total monomer content (100% by weight) of the acrylic copolymer.

The monomer having a crosslinking functional group reacts with the crosslinking agent to impart cohesive force or adhesive strength by chemical bonding so that cohesive force of the adhesive is not destroyed under high temperature or high humidity conditions. For example, a sulfonic acid group-containing monomer, a phosphate group-containing monomer, Cyano group-containing monomers, vinyl esters, aromatic vinyl compounds, carboxyl group-containing monomers, acid anhydride group-containing monomers, hydroxy group-containing monomers, amide group-containing monomers, amino group-containing monomers, imide group-containing monomers, epoxy group-containing monomers, ether group-containing monomers, and the like. Can be used, and these can be used individually or in combination of 2 or more types.

Examples of the sulfonic acid group-containing monomer include styrenesulfonic acid, allylsulfonic acid, 2- (meth) acrylamido-2-methylpropanesulfonic acid, (meth) acrylamidopropanesulfonic acid, sulfopropyl (meth) acrylate, (meth) ) Acryloyloxy naphthalene sulfonic acid, sodium vinyl sulfonate, etc. are mentioned.

2-hydroxyethyl acryloyl phosphate is mentioned as said phosphoric acid group containing monomer.

(Meth) acrylonitrile is mentioned as said cyano group containing monomer.

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

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

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

As said acid anhydride containing monomer, maleic anhydride, itaconic anhydride, these acid anhydrides, etc. are mentioned.

As the hydroxy group-containing monomer, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methylacrylate, N-methyl All (meth) acrylamide, vinyl alcohol, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, etc. are mentioned.

Examples of the amide group-containing monomer include (meth) acrylamide, diethylacrylamide, N-vinylpyrrolidone, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N'-methylenebisacrylamide, N, N- dimethylaminopropyl (meth) acrylamide, diacetone acrylamide, etc. are mentioned.

Examples of the amino group-containing monomers include aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, and (meth) acryloyl morpholine. Can be mentioned.

Cyclohexyl maleimide, isopropyl maleimide, N-cyclohexyl maleimide, itaciconimide etc. are mentioned as said imide group containing monomer.

Examples of the epoxy group-containing monomers include glycidyl (meth) acrylate, methylglycidyl (meth) acrylate, allyl glycidyl ether, and the like.

The ether group-containing monomers include 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, and acryloyl. Morpholine, and the like.

The monomer having a crosslinking functional group is preferably contained in 1 to 50% by weight relative to the total monomer content (100% by weight) of the copolymer.

The acrylic copolymer composed of the above components can be prepared by conventional methods such as solution polymerization, photopolymerization, bulk polymerization, suspension polymerization and emulsion polymerization, and preferably by solution polymerization.

The acrylic copolymer has a weight average molecular weight (polystyrene equivalent) measured by gel permeation chromatography (GPC) method is 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 is used to reinforce the cohesive force of the pressure-sensitive adhesive by appropriately crosslinking the acrylic copolymer, and an isocyanate compound, an epoxy compound, a melamine resin, an aziridine compound, or the like can be used, and preferably an isocyanate compound or an epoxy compound can be used. have. These can be used individually or in combination of 2 or more types.

As said isocyanate compound, tolylene diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, 2, 4- diphenyl methane diisocyanate, 4, 4- diphenyl methane diisocyanate, isophorone diisocyanate, tetramethyl xylene diisocyanate And naphthalene diisocyanate.

Examples of the epoxy compound include ethylene glycol diglycidyl ether, triglycidyl ether, trimethylolpropane triglycidyl ether, N, N, N ', N'-tetraglycidyl diamine, glycerin diglycidyl ether, and 1 , 3-bis (N, N- diglycidylaminomethyl) cyclohexane, etc. are mentioned.

Hexamethylol melamine is mentioned as said melamine type resin.

Examples of the aziridine-based compound include N, N'-toluene-2,4-bis (1-aziridinecarboxide) and N, N'-diphenylmethane-4,4'-bis (1-aziridinecarboxa) Id), triethylene melamine, bisisoprotaloyl-1- (2-methylaziridine), tri-1-aziridinylphosphine oxide, etc. are mentioned.

The crosslinking agent is preferably included in 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 parts by weight, the adhesive force or cohesive force of the pressure-sensitive adhesive is not good, and if it exceeds 15 parts by weight, the compatibility is reduced, the surface migration may occur and the crosslinking reaction is too advanced to reduce the adhesive strength.

In addition, as said crosslinking agent, an ultraviolet curable polyfunctional (meth) acrylate type monomer can also be used. As a specific example, 1, 4- butanediol di (meth) acrylate, 1, 6- hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethyleneglycol di (meth) acrylate, dicyclo Fentanyldi (meth) acrylate, caprolactone modified dicyclopentenyldi (meth) acrylate, ethylene oxide modified phosphoric acid di (meth) acrylate, di (acryloxyethyl) isocyanurate, allylated cyclohexyldi (meth) Bifunctional such as) acrylate, dimethylol dicyclopentanediacrylate, ethylene oxide modified hexahydrophthalic acid diacrylate, tricyclodecane dimethanol acrylate, neopentyl glycol modified trimethylolpropanediacrylate and adamantane diacrylate Acidic monomers; Trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane 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 6 functional monomers, such as caprolactone modified dipentaerythritol hexa (meth) acrylate, etc. are mentioned. These can be used individually or in combination of 2 or more types.

The ultraviolet curable polyfunctional (meth) acrylate-based monomer is preferably included in 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-based monomer may be used together with a photopolymerization initiator that generates radicals or cations by irradiation with ultraviolet rays.

Specific examples of the photoinitiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2, 2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenylketone , 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propane-1-one, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl Ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-amino Anthraquinone, 2-methyl thioxanthone, 2-ethyl thioxanthone, 2-chlorothioxanthone, 2,4-dimethyl thioxanthone, 2,4-diethyl thioxanthone, benzyl dimethyl ketal, acetophenone dimethyl Ketal, p-dimethylaminobenzoic acid 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 included 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).

Antistatic agents are conductive polymers, in particular conductive polymers polymerized in the presence of organic solvent dispersible dopants. Here, the 'organic solvent dispersible dopant' refers to a dopant which is an anionic surfactant used in the polymerization of the conductive polymer, and the conductive polymer polymerized using the organic polymer disperses in the organic solvent.

More specifically, the conductive polymer polymerized in the presence of the organic solvent dispersible dopant of the present invention polymerizes the monomer for polymerizing the conductive polymer in the presence of an anionic surfactant, which is a dopant, and the dopant is doped with an ionic bond to the conductive polymer. The charge is balanced to stabilize the polaron of the conductive polymer backbone, so that the dispersibility of the organic solvent is excellent and there is no de-doping phenomenon.

The conductive polymer may use at least one selected from the group consisting of polythiophene, polyacetylene, polyaniline, polypyrrole, polyphenylene, and derivatives thereof polymerized in the presence of an organic solvent dispersible dopant, and ease of manufacture and conductivity This excellent poly (3,4-ethylenedioxythiophene) (EDOT) is more preferred.

As the organic solvent dispersible dopant, one or more compounds selected from the group consisting of the compounds of Formulas 1 to 6 may be used.

In Chemical Formulas 1 to 6, the substituent R is a hydrocarbon group having 4 to 18 carbon atoms, for example, an alkyl group having 4 to 18 carbon atoms, an isoalkyl group, an alkoxy group, an alkoxyalkyl group, an alkylsulfonyl group, an alkoxysulfonyl group, or an alkylsilane. Group or alkoxysilane group. The substituents X may be the same or different, and each may be one substituent selected from the group consisting of a sulfonate group, a carboxylate group, a phosphate group, a cyanate group and a silicate group, preferably a sulfonate group. In addition, M may be one metal or ammonium selected from the group consisting of Li, Na and K, and n is an integer of 1 to 20.

The organic solvent dispersable dopant as described above may be added to water, which is a solvent, and stirred, followed by addition and polymerization of a conductive polymer polymerization monomer, an initiator, and an oxidizing agent, thereby preparing a conductive polymer.

The dopant may be used in an amount of 1 to 600 parts by weight based on 100 parts by weight of the monomer used for the polymerization of the conductive polymer.

In addition, the dopant is preferably pH of 5.0 to 6.5 in order to ensure effective doping of the organic solvent dispersible dopant to the conductive polymer and the ideal mechanical strength of the polymerized conductive polymer.

The oxidizing agent may be used paratoluene iron sulfate (III), metatoluene iron sulfate (III), trifluororosulfate iron (III) or iron sulfate (III), etc., the total reactants used for the polymerization of the conductive polymer It can be used in less than 40 parts by weight.

As described above, the conductive polymer polymerized in the presence of the organic solvent dispersible dopant has excellent compatibility with the acrylic copolymer, which is a pressure-sensitive adhesive resin, so that there is no problem such as surface migration and impart antistatic property with durability of the pressure-sensitive adhesive. In addition, it can exhibit excellent antistatic properties unique to the conductive polymer. On the other hand, when the organic solvent dispersible dopant is added after the conductive polymer is prepared without adding the polymer during the polymerization of the conductive polymer, the doping by the ionic bond between the dopant and the conductive polymer is not performed well, even if doped. Not only this is small but also the doping phenomenon is prone to occur when used for a long time at high temperature can be transferred to the surface when applied to the pressure-sensitive adhesive layer.

An example of the structure of poly (3,4-ethylenedioxythiophene) (EDOT) polymerized in the presence of the organic solvent dispersible dopant may be represented by the following Chemical Formula 7, but is not limited thereto. In general, for the structural analysis, the separation of the compound should be possible. However, when the polymer is prepared by polymerization, it is difficult to identify the exact structure formed. Also, as in the present invention, the portion of the organic polymer dispersable dopant doped during the polymerization of the conductive polymer is a conductive polymer. It is difficult to specify the structure of the final conductive polymer because it depends on the part where the unlocalized double bonds are located.

Wherein AS ⁻ is an organic solvent dispersible dopant.

The content of the antistatic agent is not particularly limited, and it is preferably included in 0.001 to 5 parts by weight, more preferably 0.02 to 1 part by weight, most preferably 0.05 based on 100 parts by weight of the pressure-sensitive adhesive resin (based on the solid content). To 0.5 parts by weight. If the content is less than 0.001 parts by weight, the effect of imparting antistatic properties may be insignificant, and if the content exceeds 5 parts by weight, the transmittance of the pressure-sensitive adhesive may be poor due to the color peculiar to the conductive polymer, thereby deteriorating optical properties.

In the present invention, the antistatic agent may be a solution further comprising an organic solvent. The organic solvent is used to improve the dispersibility in applying the conductive polymer polymerized in the presence of the organic solvent dispersible dopant to the pressure-sensitive adhesive resin. That is, by dissolving (dispersing) the polymerized conductive polymer in an organic solvent and then applying it to the adhesive resin, there is no problem in compatibility between the polymerized conductive polymer and the adhesive resin, thereby improving antistatic properties.

Examples of the organic solvent include alcohols, acetates, ethers, ketones, aromatic hydrocarbons, halogenated hydrocarbons and cyclic esters, and these may be used alone or in combination of two or more thereof as a mixed solvent.

Specific examples include n-butanol, butyl acetate, carbon tetrachloride, chloroform, 1,2-dichloroethane, dichloromethane, ethyl acetate, diethyl ether, methyl-t-butyl ether, methyl ethyl ketone, acetone, diisopropyl Ether, toluene, trichloroethylene and the like. More preferably, ethyl acetate, methyl ethyl ketone and acetone are considered in consideration of compatibility with a solvent used for producing the pressure-sensitive adhesive resin.

The content of the organic solvent is not particularly limited and may be included in a content capable of sufficiently dissolving the conductive polymer polymerized in the presence of the organic solvent dispersible dopant. As a specific example, it is preferable that it is 50-3000 weight part with respect to 100 weight part (solid content basis) polymerized in the presence of an organic solvent dispersible dopant, More preferably, it is 100-1000 weight part.

The antistatic pressure-sensitive adhesive composition comprising the above components may further include a silane coupling agent, if necessary, in order to better adhere the adhesiveness to the liquid crystal cell or the substrate.

Specific examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropyltriethoxysilane , 3-mercaptopropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, etc. are mentioned, These can be used individually or in combination of 2 or more types. The silane coupling agent may be included 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).

In addition, the pressure-sensitive adhesive composition is a tackifying resin, antioxidant, corrosion inhibitor, leveling agent, surface lubricant, dye, pigment, antifoaming agent, filler in order to adjust the adhesion, cohesion, viscosity, elastic modulus, glass transition temperature, etc. It may further include additives such as light stabilizers.

The antistatic adhesive composition may be used as both a polarizing plate or a surface protective film adhesive. Also, it can be used as protective film, reflective sheet, structural adhesive sheet, photo adhesive sheet, lane marking adhesive sheet, optical adhesive product, adhesive for electronic parts, as well as general commercial adhesive sheet product and medical patch.

The polarizing plate of the present invention is characterized in that the antistatic adhesive layer made of the antistatic adhesive composition is laminated.

The polarizing plate includes a polarizer (or “polarizing film”), and on one side of the polarizer, a polarizer protective film for protecting the polarizer, a pressure-sensitive adhesive layer and a release film, which are combined with a liquid crystal cell, are sequentially stacked, and the polarizer On the other side of the polarizer protective film is provided with a multilayer structure.

As said polarizer, the thing in which the dichroic dye was adsorption-oriented to the film which consists of polyvinyl alcohol-type resin can be used. As a polyvinyl alcohol-type resin which comprises the said polarizer, the copolymer etc. of polyvinyl acetate which is a homopolymer of vinyl acetate, a vinyl acetate, and the other monomer copolymerizable with this can be used. In this case, examples of the other monomer copolymerizable with vinyl acetate 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 may be manufactured to a conventional thickness.

The polarizer protective film is preferably excellent in transparency, mechanical strength, thermal stability, moisture shielding, isotropy, etc., for example, polyester-based films such as polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate; Cellulose films such as diacetyl cellulose and triacetyl cellulose; Polycarbonate film; Acrylic films such as polymethyl (meth) acrylate and polyethyl (meth) acrylate; Styrene films such as polystyrene and acrylonitrile-styrene copolymers; Polyolefin-based films such as polyethylene, polypropylene, cyclo- or polyolefin-based films having a norbornene structure, and ethylene propylene copolymers; Polyimide film; Polyether sulfone-based film; A sulfone film etc. can be used, The thickness of these is also not specifically limited.

The release film is a film for protecting the antistatic pressure-sensitive adhesive layer, the type is not particularly limited as long as it is a film commonly used in the art. Specific examples include polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate Polyolefin films such as copolymers and ethylene-vinyl alcohol copolymers; Polyester-based films such as polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate; Polyamide films such as polyacrylate, polystyrene, nylon 6 and partially aromatic polyamide; Polyvinyl chloride film; Polyvinylidene chloride film; Or polycarbonate films. These can also be used by appropriately releasing a silicone, fluorine, silica powder or the like.

The method for laminating the antistatic 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 flow casted on a polarizer protective film, and an air knife, gravure, reverse roll, kiss roll, spray, or blade ( Using a coating method such as a blade) method can be directly applied in a suitable development method, dried and laminated. In addition, after forming a pressure-sensitive adhesive layer by forming the pressure-sensitive adhesive layer on the silicone-coated release film by the same coating method as described above, it may be laminated on the polarizer protective film using a roll pressing device. At this time, when the ultraviolet-curable polyfunctional (meth) acrylate monomer is included as a crosslinking agent in the pressure-sensitive adhesive composition, it is preferable to irradiate ultraviolet rays after applying the pressure-sensitive adhesive composition or laminating it on the polarizer protective film using a roll pressing device. .

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

The polarizing plate may be applied to all of the conventional liquid crystal display devices, and specifically, the liquid crystal display device may include a liquid crystal panel in which a polarizing plate having an antistatic adhesive layer is laminated on one or both sides of the liquid crystal cell.

Surface protection film of the present invention is a film for protecting the outermost layer of the optical film, in particular the polarizing plate, characterized in that the antistatic pressure-sensitive adhesive layer and the release film made of the antistatic pressure-sensitive adhesive composition on the base film sequentially laminated. .

A base film is used as a base material for laminating an adhesive layer, Polycarbonate film; Polyester-based films such as polyethylene terephthalate; Polyether sulfone-based film; Or polyolefin films such as polyethylene, polypropylene, cyclo or norbornene structures, polyolefin films such as ethylene propylene copolymers, and the like. At this time, in order to improve the adhesiveness with the pressure-sensitive adhesive may be subjected to surface treatment or primer treatment on one or both sides of the base film.

The release film is a film for protecting the antistatic pressure-sensitive adhesive layer, the same as that used in the polarizing plate may be used.

The method of laminating an antistatic adhesive layer on the base film may use the same method as that of laminating an adhesive layer on the polarizing plate.

The thickness of the antistatic pressure-sensitive adhesive layer can be adjusted according to the adhesive force, it is usually 2 to 100㎛, preferably 5 to 50㎛.

The surface protection film is applicable to both optical members such as polarizing plates and ordinary liquid crystal display devices.

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but the following examples are merely for exemplifying the present invention, and it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention. It is natural that such variations and modifications fall within the scope of the appended claims.

In the following Preparation Examples, Examples and Comparative Examples, "%" and "parts" indicating contents are by weight unless otherwise specified.

Preparation Example 1 Preparation of Antistatic Agent A

2.5L of distilled water and 145g of 31% sodium lauryl sulfate (SLS) were added to a 5L reactor equipped with a stirrer and a nitrogen filling device and stirred at room temperature. The reactor was replaced with nitrogen for 30 minutes, followed by dropwise addition of 28.1 g (0.2 mol) of 3,4-ethylenedioxythiophene, 66 g (0.27 mol) of sodium persulfate and 0.5 g (125 mmol) of iron sulfate. Proceeded. The reaction mixture was stirred at 25 ° C. for 24 hours and then passed through an ion exchange resin (300 mL Lewatit ^™ S100MB + 500 mL Lewatit ^™ M600MB) twice to remove residual initiator and oxidant ions. Further, the mixture was stirred at 90 ° C. for 1 hour to polymerize poly (3,4-ethylenedioxythiophene), a conductive polymer, and then to the polymerized poly (3,4-ethylenedioxyti) by adding 250 g of ethyl acetate (EA) thereto. Offen) was extracted. An ethyl acetate (EA) solution in which poly (3,4-ethylenedioxythiophene) was dissolved was used as an antistatic agent A (manufactured by Sooyang Chemtech Co., Ltd.).

Preparation Example 2 Preparation of Antistatic Agent B

Except for using sodium lauryl ether sulfate (SLES) as an organic solvent dispersible dopant, and methyl ethyl ketone (MEK) as the extraction solvent of the conductive polymer was carried out in the same manner as in Preparation Example 1 Suyang Chemtech Co., Ltd. was prepared.

Preparation Example 3 Preparation of Antistatic Agent C

An antistatic agent C (manufactured by Sooyang Chemtech Co., Ltd.) was prepared in the same manner as in Preparation Example 1, except that sodium octyl sulfate (SOS) was used as an organic solvent dispersible dopant, and acetone was used as an extraction solvent for the conductive polymer. It was.

Example 1

A 4-neck jacket reactor (1L) was equipped with a stirrer, a thermometer, a reflux condenser, a dropping lot, and a nitrogen gas inlet tube. Nitrogen gas was added to the reactor for replacement, and then 164 parts of ethyl acetate, n- 126 parts of butyl acrylate, 0.5 part of acrylic acid, and 1.3 part of # 2-hydroxyethyl acrylate were thrown in, and the reactor external temperature was heated up at 50 degreeC. Then, a solution in which 0.14 parts of 2,2'-azobisisobutyronitrile (AIBN) was completely dissolved in 10 parts of ethyl acetate was added dropwise to the reactor. After the reaction was continued for an additional 5 hours while maintaining the jacket outside temperature at 50 ° C, 90 parts of ethyl acetate was slowly added dropwise using a dropping lot for 1 hour. In addition, after further stirring for 6 hours at the same temperature, 304 parts of ethyl acetate was added, followed by stirring for 2 hours to obtain a final alkyl (meth) acrylate copolymer. The prepared alkyl (meth) acrylate copolymer had a solid content of 20% and a weight average molecular weight (in terms of polystyrene) of GPC method was about 1,500,000.

100 parts of acrylic pressure-sensitive adhesive resin (based on the solid content) prepared above, 0.8 parts of trimethylolpropane-modified tolylene diisocyanate (Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.), an antistatic agent prepared in Preparation Example 1 as an antistatic agent 1.0 part of A (based on solids content) was added thereto, and diluted to an appropriate concentration with ethyl acetate to prepare an adhesive composition.

The prepared pressure-sensitive adhesive composition was applied on a polyethylene terephthalate film (41 cm × 34 cm) coated with a silicone release agent to have a dry film thickness of 25 μm, and dried at 100 ° C. for 1 minute to form a pressure-sensitive adhesive layer. The polarizing plate was laminated on a conventional polarizing plate to prepare a polarizing plate to which an adhesive was applied, and was cured at 25 ° C. and a relative humidity of 50% for 7 days.

Example 2

Except for using the antistatic agent B prepared in Preparation Example 2 was carried out in the same manner as in Example 1.

Example 3

Except for using the antistatic agent C prepared in Preparation Example 3 was carried out in the same manner as in Example 1.

Example 4

Except for using an antistatic agent A (based on the solid content) in 0.5 parts was carried out in the same manner as in Example 1.

Example 5

The same procedure as in Example 1 was carried out except that 0.1 part of the antistatic agent A (based on the solid content) was used.

Example 6

Except for using an antistatic agent A (based on the solid content) of 0.05 parts in the same manner as in Example 1.

Comparative Example 1

The antistatic agent was used in the same manner as in Example 1, except that 1.0 part of the antistatic agent D, Cornisol H4 (Inscon Corporation), a water-dispersible PEDOT product was used.

Comparative Example 2

The antistatic agent was used in the same manner as in Example 1, except that 1.0 part of the antistatic agent E, PED-A60 (solvent: ethyl acetate, polymers, Inc.), which was an organic solvent dispersible PEDOT having a solid content of 2%, was used.

Comparative Example 3

The same procedure as in Example 1 was conducted except that 1.0 part of LiClO ₄ was used as an antistatic agent.

Comparative Example 4

Except for using 1.0 part of IL-P14-2 (4-methyl-1-hexylpyridinium hexafluorophosphate) as an antistatic agent was carried out in the same manner as in Example 1.

Test Example

Physical properties of the pressure-sensitive adhesive layer prepared in Examples and Comparative Examples were measured by the following method, and the results are shown in Table 1 below.

* Surface resistivity (Ω / □)

-Measuring instrument: Surface resistance measuring instrument (MCP-HT450 / MITSUBISHI CHEMICAL)

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

Measurement method: After peeling off the PET film, three points on the surface of the pressure-sensitive adhesive layer were measured 10 times, respectively, and the average values were represented.

* Saturated saturation voltage (kV) and large voltage half-life (sec)

-Measuring instrument: Static electricity research equipment (STATIC HONESTMETER Type H-0110 / SHISHIDO ELECTRONSTATIC)

Measurement method: The prepared polarizing plate was cut into 3 cm x 3 cm to prepare a specimen, and after peeling off the PET film, it was mounted on a holder and measured three times under the following conditions, and the average value was represented.

Applied voltage: 10kV, 30 seconds

Voltage application height: 2cm

* Determination of compatibility

Phenomena such as precipitation or agglomeration after preparing the pressure-sensitive adhesive composition by mixing the pressure-sensitive adhesive resin, the crosslinking agent and the antistatic agent were visually confirmed.

○: No precipitation or agglomeration phenomenon (good)

△: slight precipitation or agglomeration phenomenon (usually)

×: Precipitation or agglomeration phenomenon (defect)

* durability

The prepared pressure-sensitive adhesive sheet was cut to have a diagonal length of 15 inches, and then bonded to Corning's # 1737 glass to prepare a specimen. The prepared specimens were treated in an autoclave for 5 minutes at 50 ° C. for 20 minutes and then left in an oven at 60 ° C. and 90% relative humidity for 300 hours. Peeling phenomenon such as lifting and peeling of the specimen left undisturbed, and whether bubbles were generated were visually confirmed and evaluated based on the following criteria.

○: No peeling phenomenon or bubbles (good)

△: peeling phenomenon and bubbles are somewhat generated

×: peeling phenomenon and bubbles are generated (defect)

division Surface resistivity (Ω / □) Saturation to Voltage (kv) Half-life (seconds) Compatibility durability Example 1 2.12E + 08 0.01 0.02 ○ ○ Example 2 2.94E + 08 0.01 0.03 ○ ○ Example 3 3.22E + 08 0.01 0.02 ○ ○ Example 4 6.50E + 08 0.01 0.06 ○ ○ Example 5 1.81E + 10 0.2 0.07 ○ ○ Example 6 6.70E + 10 0.65 0.19 ○ ○ Comparative Example 1 OVER OVER OVER × × Comparative Example 2 OVER OVER OVER × × Comparative Example 3 4.20E + 11 2.3 6.5 ○ × Comparative Example 4 3.20E + 11 1.8 4.5 ○ ×

As shown in Table 1, the pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition of Examples 1 to 6 including the conductive polymer doped with an anionic surfactant as an antistatic agent according to the present invention is compatible with the antistatic agent and the pressure-sensitive adhesive resin and The durability was good and the antistatic property was excellent. In particular, in the case of Examples 4 to 6, it was found that not only the surface resistivity value was low but also the saturation voltage and the half-life value were low, so that it could exhibit excellent antistatic property when applied to an optical product such as a polarizing plate. In addition, it was confirmed visually that no problem of coloring resulting from the conductive polymers used in the prior art occurred.

On the other hand, Comparative Example 1, which includes a water-dispersible conductive polymer as an antistatic agent, had no compatibility with the pressure-sensitive adhesive resin, and was dispersed in an organic solvent but not polymerized in the presence of an organic solvent dispersible dopant as in the present invention. Comparative Example 2 containing a conventional conductive polymer also had no compatibility with the pressure-sensitive adhesive resin and thus had poor antistatic properties and durability. In addition, Comparative Examples 3 and 4 containing the ionic compound had poor durability.

Claims (13)

As an adhesive composition containing an adhesive resin, a crosslinking agent, and an antistatic agent, The antistatic agent is an antistatic adhesive composition for polarizing plates, characterized in that the conductive polymer polymerized in the presence of an organic solvent dispersible dopant. The polarizing plate of claim 1, wherein the conductive polymer is at least one conductive polymer selected from the group consisting of polythiophene, polyacetylene, polyaniline, polypyrrole, polyphenylene, and derivatives thereof polymerized in the presence of an organic solvent dispersible dopant. Antistatic adhesive composition for use. The antistatic adhesive composition for polarizing plate according to claim 1 or 2, wherein the organic solvent dispersible dopant is one or more selected from the group consisting of Chemical Formulas 1 to 6. [Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

[Wherein R is a hydrocarbon group of 4 to 18 carbon atoms, X may be the same or different and is one substituent selected from the group consisting of sulfonate group, carboxylate group, phosphate group, cyanate group and silicate group , M is one metal or ammonium selected from the group consisting of Li, Na and K, n is an integer from 1 to 20]. The antistatic adhesive composition for polarizing plate according to claim 3, wherein X is a sulfonate group. The antistatic adhesive composition for polarizing plate according to claim 1 or 2, wherein the conductive polymer is a conductive polymer represented by Formula 7. [Formula 7]

(Wherein AS ⁻ is an organic solvent dispersible dopant). The method of claim 1, wherein the antistatic agent is n-butanol, butyl acetate, carbon tetrachloride, chloroform, 1,2-dichloroethane, dichloromethane, ethyl acetate, diethyl ether, methyl-t-butyl ether , Methyl ethyl ketone, acetone, diisopropyl ether, toluene and trichloroethylene, the antistatic pressure-sensitive adhesive composition for polarizing plates which is a solution further comprising at least one organic solvent selected from the group consisting of. The antistatic adhesive composition for polarizing plate according to claim 1 or 2, wherein the antistatic agent is a solution further comprising at least one organic solvent selected from the group consisting of ethyl acetate, methyl ethyl ketone, and acetone. The antistatic adhesive composition for polarizing plate according to claim 1 or 2, wherein the content of the dopant is 1 to 600 parts by weight based on 100 parts by weight of the monomer used for the polymerization of the conductive polymer. The antistatic adhesive composition for polarizing plate according to claim 1 or 2, wherein the antistatic agent is contained in an amount of 0.001 to 5 parts by weight based on 100 parts by weight of the pressure sensitive adhesive resin (solid content). The antistatic adhesive composition for polarizing plates according to claim 1, wherein the antistatic agent is contained in an amount of 0.05 to 0.5 parts by weight based on 100 parts by weight of the adhesive resin (solid content). The polarizing plate of the pressure-sensitive adhesive layer made of the antistatic pressure-sensitive adhesive composition according to claim 1 or 2 is laminated. The surface protective film laminated pressure-sensitive adhesive layer of the antistatic pressure-sensitive adhesive composition according to claim 1 or claim 2. A liquid crystal display device comprising a polarizing plate according to claim 11 on at least one side of a liquid crystal cell.