KR101612350B1 - Anti-static adhesive composition, polarizing plate and surface protective film using the composition - Google Patents

Abstract

The present invention relates to an antistatic pressure-sensitive adhesive composition, a polarizing plate using the same, and a surface protective film, and more particularly, to an antistatic property improving agent containing a polyhydroxyalkanoic acid represented by the following formula An antistatic pressure-sensitive adhesive composition capable of sufficiently suppressing the generation of static electricity and giving an improved antistatic property due to the synergistic action of the antistatic agent and the antistatic property improving agent without deteriorating the physical properties of the pressure-sensitive adhesive itself, and a polarizing plate and surface protective film Lt; / RTI >

Wherein m is an integer of 1 or more, R ₁ and R ₂ are each independently hydrogen or an alkyl group having 1 to 12 carbon atoms, and R ₃ is hydrogen or an alkyl group having 1 to 4 carbon atoms.

Antistatic, pressure-sensitive adhesive, polarizer, surface protective film, polyhydroxyalkanoic acid

Description

TECHNICAL FIELD [0001] The present invention relates to an antistatic pressure-sensitive adhesive composition, and a polarizing plate and a surface protective film using the same. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to an antistatic pressure-sensitive adhesive composition capable of imparting improved antistatic properties without deteriorating the physical properties of the pressure-sensitive adhesive itself, and a polarizing plate and a surface protective film using the same.

In general, a liquid crystal display device (LCD) requires a liquid crystal cell containing 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 should 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 aligned, and a polarizer And a polarizer protective film laminated thereon. Specifically, a polarizer protective film such as triacetyl cellulose (TAC), a pressure sensitive adhesive layer to be bonded to the liquid crystal cell on the protective film, and a release film are sequentially provided on one side of the polarizer, A multilayer laminate in which a polarizer protective film and a surface protective film are laminated in order.

In the process of adhering the polarizing plate having such a structure to the liquid crystal cell, the releasing film is first peeled off from the pressure-sensitive adhesive layer, and after peeling off the surface protecting film in the post-process after being attached to the liquid crystal cell. Since the release film and the surface protection film are composed of a plastic material, the electrical insulation is high and static electricity is generated at the time of peeling.

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, the size of a polarizing plate used in the manufacture of a liquid crystal display device has been enlarged due to the enlargement of a liquid crystal display panel. In addition, as the process speed is increased to improve productivity, the amount of static electricity is further increased, And there is a desperate need for a method for rapidly removing the generated static electricity.

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 that transparency is lowered because an excessive amount of conductive metal powder or carbon particles must be used. The surfactant is easily affected by humidity and the adhesive property is deteriorated due to the property of migration to the surface of the pressure- .

On the other hand, Japanese Patent 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 interior of the pressure sensitive adhesive. 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 Apr. 9, 2004) discloses a method of preparing a pressure-sensitive adhesive by adding an organic salt and using the pressure-sensitive adhesive to prepare a pressure-sensitive adhesive layer having a surface resistivity of 10 ¹³ Ω / , There is a problem that the organic salt is expensive and an excessive amount of the organic salt is used.

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 has a problem in that when the crosslinking agent is isocyanate, And the hydrophilic property of ethylene oxide may cause surface migration to deteriorate the adhesive property.

It is an object of the present invention to provide a polarizing plate capable of exhibiting a high antistatic property required for a polarizing plate without causing a problem of lowering the durability of reliability which is caused by adding a large amount of an antistatic agent, An antistatic pressure-sensitive adhesive composition which is capable of sufficiently solving the problem of static electricity even when it is not present.

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 still another object of the present invention to provide a surface protecting film 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 polarizing plate.

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, an antistatic agent, and a polyhydroxyalkanoic acid represented by the following formula:

[Chemical Formula 1]

Wherein m is an integer of 1 or more, R ₁ and R ₂ are each independently hydrogen or an alkyl group having 1 to 12 carbon atoms, and R ₃ is hydrogen or an alkyl group having 1 to 4 carbon atoms.

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

The present invention also provides a surface protective film laminated with an antistatic pressure-sensitive adhesive layer comprising the antistatic pressure-sensitive adhesive composition.

The present invention also provides a liquid crystal display provided with a polarizing plate in which the antistatic pressure-sensitive adhesive layer is laminated.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to sufficiently suppress the generation of static electricity and to greatly improve the antistatic property without deteriorating the physical properties of the pressure-sensitive adhesive itself such as adhesiveness and endurance reliability.

The present invention relates to an antistatic pressure-sensitive adhesive composition capable of imparting improved antistatic properties without deteriorating the physical properties of the pressure-sensitive adhesive itself, and a polarizing plate and a surface protective film using the same.

Hereinafter, the present invention will be described in detail.

The antistatic pressure-sensitive adhesive composition of the present invention is characterized by comprising a pressure-sensitive adhesive resin, a crosslinking agent, an antistatic agent, and a polyhydroxyalkanoic acid represented by the following general formula (1).

[Chemical Formula 1]

Wherein m is an integer of 1 or more, R ₁ and R ₂ are each independently hydrogen or an alkyl group having 1 to 12 carbon atoms, and R ₃ is hydrogen or an alkyl group having 1 to 4 carbon atoms.

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- Butadiene rubber, polybutadiene, polyisoprene, polyisobutylene, butyl rubber, chloroprene rubber, silicone rubber and the like can be used, and an acrylic copolymer can be preferably used.

As the 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 monomer having 1 to 14 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, Octyl (meth) acrylate, isooctyl (meth) acrylate, n-hexyl (meth) acrylate, (Meth) acrylate, n-decyl (meth) acrylate, n-decyl (meth) acrylate, Acrylate, n-tetradecyl (meth) acrylate, and the like. (Meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, (Meth) acrylate, n-decyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (Meta) acrylate monomer having an alkyl group of 6 to 14 carbon atoms such as tetradecyl (meth) acrylate is preferable in that the adhesive force to the adherend is controlled to be low and the re-peelability 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) of the 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- Containing monomer, an epoxy group-containing monomer, an ether group-containing monomer, an amino group-containing monomer, an epoxy group-containing monomer, an ether group-containing monomer, Monomers and the like, which 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) Cyclohexanenaphthalenesulfonic acid, and sodium vinylsulfonate.

As the phosphoric acid group-containing monomer, 2-hydroxyethyl acryloyl phosphate can be exemplified.

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, '-Methylene bisacrylamide, 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-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 Phosphorus, and the like.

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) of the 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 .

The crosslinking agent is an isocyanate compound, an epoxy compound, a melamine resin, an aziridine compound or the like which is used for reinforcing the cohesive force of the pressure-sensitive adhesive by appropriately crosslinking the acrylic copolymer, and preferably an isocyanate compound or an epoxy compound can be used have. 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-aziridine carboxamide), N, N'-diphenylmethane-4,4'-bis (1-aziridine carboxamide ), 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). When the content is less than 0.01 part by weight, the adhesive force or cohesive force of the pressure-sensitive adhesive is not good. When the content exceeds 15 parts by weight, compatibility with other components is decreased and surface migration may occur. do.

As the crosslinking agent, an ultraviolet curable polyfunctional (meth) acrylate monomer may also 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, di (acryloxyethyl) isocyanurate, allyl cyclohexyldi (meth) acrylate, di (methoxy) acrylate, (Meth) acrylates such as trimethylolpropane diacrylate, trimethylolpropane diacrylate, trimethylolpropane diacrylate, trimethylolpropane diacrylate, trimethylolpropane diacrylate, trimethylolpropane diacrylate, trimethylolpropane diacrylate, Functional monomers; (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.

The ultraviolet curable multi-functional (meth) acrylate monomer is preferably included in an amount of 0.1 to 30 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive resin.

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, 2,2 2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenyl 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 ester 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide may be made of pins and the like, which may be used either 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.

The antistatic agent is not particularly limited as long as it is mainly used in the art. For example, a fluorinated sulfonylimide compound, a pyridinium ionic liquid or an alkali metal salt may be used, and these may be used alone or in combination of two or more.

The fluorinated sulfonylimide compound is a compound represented by the following general formula (2), which has a high degree of electronegativity of fluorine atoms of anions and thus has a low coordination bond with respect to alkali metal cations and high hydrophobicity and is excellent in compatibility with an acrylic copolymer And is free from surface migration, and is preferable in terms of endurance reliability as well as physical properties of antistatic property. In addition, since the radius of the anion is smaller than that of the perfluorinated alkylsulfonylimide, migration in the pressure sensitive adhesive is easy, and therefore, it exhibits superior antistatic properties.

(2)

_{^{M + [(SO 2 R)}} 2 N] -

Wherein M is an alkali metal and R is a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms.

The alkali metal (M) may be lithium, sodium, potassium or cesium, preferably lithium, sodium or potassium. Specifically, a lithium salt such as bis (fluorosulfonyl) imide potassium (KN (FSO ₂ ) ₂ ), bis (fluorosulfonyl) imide sodium (NaN (FSO ₂ ) ₂ ) (LiN (FSO ₂ ) ₂ ), and the like.

The pyridinium-based ionic liquid is made by combining ions of pyridinium cations and anions, which means that it is in a liquid state at room temperature (25 ° C).

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.

The anion is OTf ^- (trifluoromethyl sulfonate), OTs ^- (toluene-4-sulfonate), OMs ^{- (sulfonate), 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 ^- , among which BF ₄ ^- or PF ₆ ^- is preferable.

As the alkali metal salt, a lithium salt, a sodium salt or a potassium salt can be used. 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 ) and tris (trifluoromethanesulfonyl) methide lithium (LiC (CF ₃ SO ₂ ) ₃ ), which may be used alone or in combination of two or more. Of these, the cation is preferably a lithium salt and the anion is preferably a hexafluorophosphate salt, more preferably lithium iodide or lithium perchlorate.

The antistatic agent is preferably included in an amount of 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, and most preferably 0.3 to 3 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 0.01 part by weight, the effect of imparting antistatic properties may be insignificant. When the content is more than 10 parts by weight, the cohesiveness of the pressure-sensitive adhesive may be poor and durability may be deteriorated.

The present invention is characterized in that it comprises a polyhydroxyalkanoic acid represented by the following formula (1) serving as an antistatic-improving agent together with the above-mentioned components. The polyhydroxyalkanoic acid contains a large number of hydroxy groups and double bonds in the compound itself, and when used together with the antistatic agent, the polyhydroxyalkanoic acid is in a state of coordination bonding with the elements of the double bond, Respectively. That is, since the hydroxy group and the double bond of the polyhydroxyalkanoic acid can be electronically exchanged with the antistatic agent, the electrolyte can serve as an electrolyte, thereby improving the antistatic property. In addition, in the case of using polyhydroxyalkanoic acid, it is possible to maintain the durability reliability while maintaining the durability reliability even though the same content is used, without the problem of lowering the durability reliability, which is caused when the content of the antistatic agent is increased, It is possible to improve the property.

[Chemical Formula 1

Wherein m is an integer of 1 or more, R ₁ and R ₂ are each independently hydrogen or an alkyl group having 1 to 12 carbon atoms, and R ₃ is hydrogen or an alkyl group having 1 to 4 carbon atoms.

The polyhydroxyalkanoic acid is preferably polylactic acid.

The polyhydroxyalkanoic acid may have a weight average molecular weight of 1,000 or more, preferably 1,000 to 500,000, more preferably 10,000 to 500,000, and most preferably 100,000 to 150,000. If the weight-average molecular weight exceeds 500,000, the physical properties of the pressure-sensitive adhesive become hard and the durability of the pressure-sensitive adhesive may be deteriorated. In the formula (1), m may be a maximum value according to the weight average molecular weight of the polyhydroxyalkanoic acid.

The amount of the polyhydroxyalkanoic acid is preferably 0.5 to 11 parts by weight, more preferably 1 to 10 parts by weight, and most preferably 1.5 to 4.5 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive resin (based on the solid content) good. When the content is less than 0.5 parts by weight, the antistatic property is insignificantly improved. When the content is more than 11 parts by weight, the antistatic property improving effect is small, which is uneconomical and the adhesive property can be lowered.

The antistatic pressure-sensitive adhesive composition containing the above-mentioned components may further include a silane coupling agent if necessary in order to improve adhesion when bonded to the liquid crystal cell or the substrate.

Specific examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, -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 solids 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, Or an additive such as a light stabilizer.

The antistatic pressure-sensitive adhesive composition may be used as a pressure-sensitive adhesive for a polarizing plate or a surface protective film. In addition, it can be used not only as a protective film, a reflective sheet, a structural adhesive sheet, a photographic adhesive sheet, a lane marking adhesive sheet, an optical adhesive product, an electronic component adhesive, but also a general commercial adhesive sheet product or a medical patch.

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), and a polarizer protective film for protecting the polarizer, a pressure-sensitive adhesive layer for bonding the liquid crystal cell, and a release film are sequentially laminated on one surface 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 dichromatic 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, and other monomer copolymerizable with vinyl acetate, or 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 polyolefins such as 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 releasing treatment by a silicone system, a fluorine system, a silica powder, or the like.

The method for 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 fluid casting method and an air knife, a gravure, a reverse roll, a kiss roll, a spray, or a blade ) Method or the like, and then dried and laminated. Alternatively, a pressure-sensitive adhesive layer may be formed on the silicone-coated release film by the same application method as described above, and then the pressure-sensitive adhesive sheet may be laminated on the polarizer protective film by using a roll pressing apparatus. When the ultraviolet curable multi-functional (meth) acrylate monomer is included in the pressure-sensitive adhesive composition as a crosslinking agent, it is preferable to apply ultraviolet rays after coating the pressure-sensitive adhesive composition or by laminating it on a polarizer protective film by using a roll- .

The thickness of the antistatic pressure-sensitive adhesive layer can be adjusted in accordance with the adhesive force, and is preferably 3 to 100 占 퐉, more preferably 10 to 100 占 퐉.

Such a polarizing plate can be applied to all ordinary liquid crystal display devices. Specifically, a liquid crystal display device including a liquid crystal panel in which a polarizing plate in which an antistatic pressure-sensitive adhesive layer is laminated is bonded to at least one surface of a liquid crystal cell can be constituted.

The surface protective film of the present invention is characterized in that an antistatic pressure-sensitive adhesive layer composed of the antistatic pressure-sensitive adhesive composition and a release film are sequentially laminated on a substrate film as a film for protecting an outermost layer of an optical film, particularly a polarizing plate .

The base film is used as a base material for laminating the pressure-sensitive adhesive layer, and includes a polycarbonate film; Polyester films such as polyethylene terephthalate; Polyethersulfone-based films; Or polyolefin-based films such as polyethylene, polypropylene, cyclo-based or norbornene-based structures, and ethylene-propylene copolymers. At this time, one surface or both surfaces of the base film may be subjected to a surface treatment or a primer treatment in order to improve adhesion with a pressure-sensitive adhesive.

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

As a method for laminating the antistatic pressure-sensitive adhesive layer on the base film, the same method as that for laminating the pressure-sensitive adhesive layer on the polarizing plate can be used.

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

Such a surface protective film can be applied to both optical members such as polarizing plates and the like and to ordinary liquid crystal display devices.

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. It is natural that these modifications and modifications are included in the appended claims.

[Example]

Production Example: Preparation of Acrylic Copolymer

A four neck jacket reactor (1 L) was equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas introducing tube. The reactor was purged with nitrogen gas, and then 164 parts by weight of ethyl acetate, 126 parts by weight of butyl acrylate, 0.5 part by weight of acrylic acid and 1.3 parts by weight 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 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) was completely dissolved in 10 parts by weight of ethyl acetate was added dropwise to the reactor. The reaction was continued for an additional 5 hours while keeping the jacket temperature at 50 캜, and then 90 parts by weight of ethyl acetate was slowly added dropwise for 1 hour using a dropping funnel. After further stirring at the same temperature for 6 hours, 304 parts by weight of ethyl acetate was added, and the mixture was further stirred for 2 hours to obtain an acrylic copolymer.

The prepared acrylic copolymer had a solid content of 20% and a weight average molecular weight (in terms of polystyrene) of about 1,500,000 by GPC.

Example 1

0.8 parts by weight of trimethylolpropane-modified tolylene diisocyanate (Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.) as a crosslinking agent, 0.8 parts by weight of bis (fluorosulfuric acid) as an antistatic agent, 0.02 part by weight of polyvinylidene fluoride (KN (FSO ₂ ) ₂ ) and ₁ part by weight of polylactic acid (weight average molecular weight 1,000,000-1,500,000) as an antistatic agent were added and diluted with ethyl acetate to an appropriate concentration to obtain a pressure- .

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. And another layer of release film was laminated thereon to prepare a pressure-sensitive adhesive sheet.

Example 2

The procedure of Example 1 was repeated, except that 3 parts by weight of polylactic acid was used.

Example 3

The procedure of Example 1 was repeated, except that 5 parts by weight of polylactic acid was used.

Example 4

The procedure of Example 1 was repeated, except that 10 parts by weight of polylactic acid was used.

Example 5

The embodiment, but the same manner as in Example 1, the polylactic acid 3 parts by using parts of, as an antistatic agent HQ-115 [bis (trifluoromethane sulfonyl) imide lithium (LiN (CF ₃ SO _{2) 2)]} 3 parts by weight .

Example 6

3 parts by weight of polylactic acid and 3 parts by weight of IL-P14-2 (4-methyl-1-hexylpyridinium hexafluorophosphate) as an antistatic agent were used in the same manner as in Example 1.

Example 7

Except that 3 parts by weight of polylactic acid was used and 0.15 part by weight of 3-glycidoxypropyltrimethoxysilane (KBM-403, Shinetsu), which is a silane coupling agent, was further used.

Comparative Example 1

The same procedure as in Example 1 was carried out except that polylactic acid was not used.

Comparative Example 2

Except that 3 parts by weight of HQ-115 [bis (trifluoromethanesulfonyl) imide lithium (LiN (CF ₃ SO ₂ ) ₂ )] was used as an antistatic agent without using polylactic acid Respectively.

Comparative Example 3

Except that polylactic acid was not used and 3 parts by weight of IL-P14-2 (4-methyl-1-hexylpyridinium hexafluorophosphate) was used as an antistatic agent.

Comparative Example 4

Except that polylactic acid was not used and 6 parts by weight of antistatic bis (fluorosulfonyl) imide potassium (KN (FSO ₂ ) ₂ ) was used in place of polylactic acid.

Comparative Example 5

Except that 6 parts by weight of HQ-115 [bis (trifluoromethanesulfonyl) imide lithium (LiN (CF ₃ SO ₂ ) ₂ )] was used as an antistatic agent without using polylactic acid Respectively.

Comparative Example 6

6 parts of IL-P14-2 (4-methyl-1-hexylpyridinium hexafluorophosphate) was used as an antistatic agent without using polylactic acid.

The components and composition 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 Public
coalescence Cross-linking agent Silane coupling agent Polylactic acid Antistatic agent COR-L KBM-403 KN (FSO ₂ ) ₂ HQ-115 IL-P14-2 Example 1 100 0.8 - One 3 - - Example 2 100 0.8 - 3 3 - - Example 3 100 0.8 - 5 3 - - Example 4 100 0.8 - 10 3 - - Example 5 100 0.8 - 3 - 3 - Example 6 100 0.8 - 3 - - 3 Example 7 100 0.8 0.15 3 3 - - Comparative Example 1 100 0.8 - - 3 - - Comparative Example 2 100 0.8 - - - 3 - Comparative Example 3 100 0.8 - - - - 3 Comparative Example 4 100 0.8 - - 6 - - Comparative Example 5 100 0.8 - - - 6 - Comparative Example 6 100 0.8 - - - - 6

Test Example

The properties of the pressure-sensitive adhesive sheets prepared in the above 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 release film of the pressure-sensitive adhesive sheet was peeled off, and the three points of the surface were measured 10 times each, and the average value thereof was evaluated.

?: Surface resistivity? 10 ⁸ (improvement)

?: 10 ⁸ <surface resistivity? 10 ¹⁰ (normal)

X: 10 ¹⁰ < Surface resistivity (not improved)

* Endurance reliability

The prepared pressure-sensitive adhesive sheet was cut to a width of 30 cm and a length of 22 cm, and then bonded to Corning # 1737 glass to prepare specimens. 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 occurrence of air bubbles (defective)

division Example Comparative Example One 2 3 4 5 6 7 One 2 3 4 5 6 Daejeon
Preventiveness △ ○ ○ ○ ○ ○ ○ × × × △ △ △ surface
Resistivity
(Ω / □) 9.26
E09 5.36
E08 4.33
E08 9.88
E08 8.93
E08 5.82
E08 6.48
E08 1.80
E10 1.35
E10 1.43
E10 5.33
E09 4.32
E09 7.33
E09 Durability
responsibility ○ ○ △ △ ○ ○ ○ ○ ○ ○ × × ×

As shown in Table 2 above, the pressure-sensitive adhesive compositions of Examples 1 to 7 containing polylactic acid as an antistatic agent as an antistatic agent together with the antistatic agent of the present invention exhibited improved durability in adhesion as well as improved antistatic properties . In addition, through Examples 1 to 4 and Comparative Examples 4 to 6, it was confirmed that when the antistatic agent is added in an excess amount to improve the antistatic property as compared with the case where the content of polylactic acid is increased, the endurance reliability is greatly lowered there was.

As described above, the present invention is expected to have an effect when applied to a polarizing plate, a surface protective film, and a liquid crystal display device which require improved antistatic properties while maintaining endurance reliability.

Claims (8)

An antistatic pressure-sensitive adhesive composition comprising a pressure-sensitive adhesive resin, a crosslinking agent, an antistatic agent, and a polyhydroxyalkanoic acid represented by the following formula (1): [Chemical Formula 1]

Wherein m is an integer of 1 or more, R ₁ and R ₂ are each independently hydrogen or an alkyl group having 1 to 12 carbon atoms, and R ₃ is hydrogen or an alkyl group having 1 to 4 carbon atoms. The method according to claim 1, Wherein the polyhydroxyalkanoic acid has a weight average molecular weight of 1,000 to 500,000. The method according to claim 1, Wherein the polyhydroxyalkanoic acid is polylactic acid. The method according to claim 1, Wherein the polyhydroxyalkanoic acid is contained in an amount of 0.5 to 11 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive resin. The method according to claim 1, Wherein the antistatic agent is at least one selected from the group consisting of a fluorinated sulfonylimide compound represented by the following formula (2), a pyridinium ionic liquid and an alkali metal salt: (2) _{^{M + [(SO 2 R)}} 2 N] - Wherein M is one alkali metal selected from the group consisting of lithium, sodium, potassium and cesium and R is a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms. A polarizing plate laminated with a pressure-sensitive adhesive layer comprising an antistatic pressure-sensitive adhesive composition according to any one of claims 1 to 5. A surface protective film laminated with a pressure-sensitive adhesive layer comprising an antistatic pressure-sensitive adhesive composition according to any one of claims 1 to 5. And a polarizing plate according to claim 6 is provided on at least one surface of the liquid crystal cell.