KR20080087972A - Antistatic pressure sensitive adhesive composition and polarized plate comprising the same - Google Patents

Abstract

An antistatic pressure-sensitive adhesive composition is provided to ensure durability, re-delamination, and antistatic property at the same time. An antistatic pressure-sensitive adhesive composition includes an acrylate copolymer having cross-linkable functional groups on the side chain, 0.5-2 parts by weight of a cross-linking agent, 0.01-1 parts by weight of a silane coupling agent, and 0.01-10 parts by weight of lithium bis(trifluoromethanesulfonyl)imide based on 100 parts by weight of the acrylate copolymer solid, wherein the acrylate copolymer having cross-linkable functional groups on the side chain has an acid value of 1.5-2.5.

Description

Antistatic pressure-sensitive adhesive composition and polarizing plate comprising the same {Antistatic pressure sensitive adhesive composition and polarized plate comprising the same}

The present invention relates to an antistatic adhesive composition and a polarizing plate including the same, and more particularly, to an adhesive composition, a polarizing plate and a liquid crystal display device using the same, which ensures durability, re-peelability, and antistatic property at the same time.

In general, in order to manufacture a liquid crystal display device, a liquid crystal cell and a polarizing plate containing a liquid crystal are basically required, and an appropriate adhesive layer or adhesive layer for bonding them should be used. In order to protect both sides of PVA (Poly vinyl alcohol), which is a polarizing film (or polarizer) which is stretched in a certain direction and dyed with an iodine compound or a dichroic polarizing material, triacetyl cellulose (TAC) is used on one side. ) Protective film is laminated, an antistatic layer, a reflective ring layer, a hard coating layer, etc. are laminated thereon, on the opposite side a protective film composed of a triacetyl cellulose film or a polymer of a cyclic olefin is laminated, and an adhesive layer thereon It consists of a multilayer structure laminated with a release film.

In manufacturing a liquid crystal display, when the release film is peeled from the pressure-sensitive adhesive layer in the process of attaching the polarizing plate to the liquid crystal cell, static electricity is generated. The generated static electricity affects the alignment of the liquid crystal inside the liquid crystal display, thereby preventing defects. It causes the contamination by foreign matter between the liquid crystal cell and the adhesive by the electrostatic attraction.

In order to solve the problem caused by the static electricity, generally in forming an adhesive layer on the protective film, a method using a conductive adhesive with a conductive material added to the adhesive, an antistatic layer by applying a conductive material between the polarizing plate and the adhesive layer The method of forming a resin and the method of using an ionic acrylate copolymer as a polymer added to an adhesive composition are used.

Hereinafter, a method of imparting antistatic property to the flat plate will be described in detail.

First, a method of imparting antistatic property by adding a conductive material to the pressure-sensitive adhesive layer includes a method of adding a material having a conductive component such as conductive polymer, metal oxide particles, or carbon particles, and ionicity such as metal salt or surfactant. The method of adding a substance to an adhesive is performed (Korea Patent Publication No. 10-1998-0081608, Korean Patent Publication No. 10-1989-00133673, Korean Patent Publication No. 10-2001-0111715, Korean Patent Korean Patent Publication No. 10-2004-0032058, Korean Patent Publication No. 10-2006-0018495, Korean Patent Publication No. 10-2004-0030919, Korean Patent Publication No. 10-2001-0010433, Korean Patent Publication 10-2005-0072576, Japanese Patent Laid-Open No. 2006-111856, Japanese Patent Laid-Open No. 2006-111846, and Japanese Patent Laid-Open No. 2006-104434).

However, when the conductive polymer, the metal oxide or the carbon particles are added, a large amount must be added in order to impart antistatic properties, thereby reducing transparency. In addition, when the surfactant is added, it is easy to be affected by humidity, and exhibits a disadvantage of lowering the adhesive physical property due to migration to the adhesive surface. As another method, there have been attempts to add ethylene oxide-modified dioctyl phthalate plasticizer to the inside of the pressure-sensitive adhesive to provide flexibility and to suppress static electricity generation. However, the addition of such a plasticizer alone is not only difficult to suppress the generation of static electricity generated initially, it is also difficult to dissipate the static electricity remaining after peeling off the release film.

Second, a method of forming an antistatic layer by applying a conductive material between the polarizing plate and the pressure-sensitive adhesive layer is a method of depositing an electrically conductive metal powder or metal oxide, coating a conductive polymer or the like. However, such a method requires an additional step of stacking an antistatic layer in imparting antistatic performance to a polarizing plate having a multilayer structure, and thus, there is a problem that the process becomes complicated and causes an increase in unit cost (Korean Patent Publication No. 10). -1997-7002906, Korean Patent Publication No. 10-2005-0036310, Japanese Patent Publication No. 2006-095875, Japanese Patent Publication No. 2006-095874, Japanese Patent Publication No. 2006-076251, Japanese Patent Publication Japanese Patent Laid-Open No. 2005-271573, Japanese Patent Laid-Open No. 2005-238651, Japanese Patent Laid-Open No. 2005-200607, Japanese Patent Laid-Open No. 11-091038, Japanese Patent Laid-Open No. 04-304921, Japanese Patent Laid-Open 10-114886).

Third, in addition to the above two methods, no additional coating process is required, and as a method for preventing the conductive material from bleeding out from the pressure-sensitive adhesive, a method of immobilizing an ionic material in a polymer as the pressure-sensitive adhesive composition has been proposed. Specifically, Korean Patent Publication No. 10-2001-0111715 prepares a polymer containing an epoxy group, adds a tertiary amine to an epoxy group to introduce a quaternary ammonium salt, and a polymer containing a tertiary amine. And a method of introducing quaternary ammonium salts by reacting dimethylsulfate with tertiary amines. However, when an excessive amount of epoxy groups or tertiary amines are introduced into the polymer in order to exhibit sufficient antistatic properties, there is a possibility that the physical properties inherent to the pressure-sensitive adhesive may be damaged.

The method of adding a conductive material to the pressure-sensitive adhesive composition of the above-mentioned methods of imparting antistatic properties to the polarizing plate will be described in more detail. 1) Conductive polymers (polythiophene, polypyrrole, polyamyline) When used, in addition to the problem that the added conductive polymer is expensive, there is a problem that opaque when using a large amount to improve the antistatic properties, 2) when using a metal oxide it is difficult to control the size of the dispersed particles, there is a fear of birefringence, 3) In the case of using organic salts, organic salts such as anion and quaternary ammonium salts, phosphonium salts, and sulfonium salts, which are weakly coordinated in consideration of their solubility, are used. There is a problem of being expensive, and the problem of leaking to the surface is serious. Finally, 4) a method of using alkali metal salts has been reported, and the most widely used method considering the cost and the leakage to the surface.

The present invention relates to an antistatic pressure-sensitive adhesive using an alkali metal salt antistatic agent in classification, and will be described in detail with respect to a technique using an alkali metal salt as an antistatic agent.

In order to improve the compatibility of alkali metal salts, antistatic pressure-sensitive adhesives containing alkali metal salts have been reported to use polyether plasticizers or to use polymers containing ether groups (Korean Patent Publication No. 10-2006). -0018495, Korean Patent Publication No. 10-2005-0072567, Japanese Patent Publication No. 2006-111856, Japanese Patent Publication No. 2006-111846, Japanese Patent Publication No. 2005-206776, Japanese Patent Publication No. 11-061085A, Korea Patent Publication No. 10-2006-0049137).

In addition, a technique of an antistatic adhesive comprising an alkali metal salt in a polymer having an acid value of the adhesive of 1.0 or less (Japanese Patent Laid-Open Publication No. 2005-314476, Japanese Patent Laid-Open Publication No. 2005-298569) has been reported. When removing, it is understood as a method for suppressing the generation of static electricity and ensuring re-peelability. However, there is a concern about durability due to lack of adhesion due to low acid value.

An object of the present invention is to solve the above problems of the prior art to develop an antistatic pressure-sensitive adhesive composition that satisfies durability, re-peelability, antistatic properties at the same time.

The present invention includes an acrylate copolymer having a crosslinkable functional group in the side chain, a crosslinking agent, a silane coupling agent, and lithium bis (trifluoromethanesulfonyl) imide, and an acrylate copolymer having a crosslinkable functional group in the side chain. An acid value of 1.5 to 2.5 relates to an antistatic adhesive composition and a polarizing plate including the same.

Acid value in the present invention is defined as the number of mg of potassium hydroxide used to neutralize 1 g of the solid content of the polymer.

As an acrylate copolymer which has a crosslinkable functional group in the side chain used by this invention, a C4-C12 alkyl (meth) acrylate monomer, the polymerizable monomer which has a crosslinkable functional group in a side chain, and another monomer as needed The alkyl (meth) acrylate type copolymer containing these is mentioned.

In the present invention, "(meth) acryl" refers to methacryl or acryl.

As said C4-C12 alkyl (meth) acrylate monomer, (meth) acrylate derived from a C4-C12 aliphatic alcohol, ie, n-butyl (meth) acrylate and 2-butyl (meth) acryl Late, t-butyl (meth) acrylate, pentyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, Usyl (meth) acrylate etc. or these 2 or more types of mixtures are mentioned. Of these, n-butyl acrylate, 2-ethylhexyl acrylate or a mixture thereof is preferred.

The polymerizable monomer which has a crosslinkable functional group in said side chain is a polymerizable monomer which has a carboxylic acid group, for example, monovalent acid, such as (meth) acrylic acid and crotonic acid, divalent acid, such as maleic acid, itaconic acid, and fumaric acid, Monoalkyl ester of such a diacid, 3- (meth) acryloyl propionic acid, a zucchini anhydride ring-opening adduct to 2-hydroxyalkyl (C2-3) (meth) acrylate, polyoxyalkylene (C2-C2) 4) Succinic anhydride ring-opening adduct to glycol mono (meth) acrylate, the compound which ring-opened and added amber acid anhydride to the caprolactone adduct to 2-hydroxyalkyl (C2-3) (meth) acrylate, etc .; Polymerizable monomer which has a hydroxy group, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, polyoxyalkylene (carbon number) 2-4) glycol mono (meth) acrylate, etc .; Or a polymerizable monomer having an amide group such as (meth) acrylamide or the like; The polymerizable monomer which has a tertiary amine group, for example, N, N- dimethylamine ethyl (meth) acrylate, etc. are mentioned.

Among them, a polymerizable monomer having a carboxylic acid group, a polymerizable monomer having a hydroxy group, or a polymerizable monomer having an amide group is preferable, and acrylic acid, 2-hydroxyethyl (meth) acrylate or (meth) acrylamide is particularly preferred. desirable.

In addition, with said other monomer, For example, a C1-C3 alkyl (meth) acrylate monomer, ie, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, etc. Or; Alkyl (meth) acrylate monomers having 13 to 18 carbon atoms, for example, tridecyl (meth) acrylate, stearyl (meth) acrylate, and the like; (Meth) acrylic acid ester monomers derived from cyclic alcohols such as cyclohexyl (meth) acrylate and the like; (Meth) acrylate monomers derived from aromatic alcohols such as benzyl (meth) acrylate and the like; Aromatic monomers such as styrene, vinyltoluene and the like; Allyl compound monomers such as allyl acetate and the like; Monomers having a nitrile group such as (meth) acrylonitrile, α-chloro (meth) acrylonitrile and the like; Halogen-containing monomers such as vinyl chloride, vinylidene chloride and the like; Vinyl ester monomers such as vinyl acetate, vinyl propionate and vinyl butyrate; Vinyl ether monomers such as vinyl ethyl ether, vinyl propyl ether, vinyl isobutyl ether, and the like, and these may include one kind or two or more kinds.

In these, methyl (meth) acrylate is preferable.

The weight ratio of the above-mentioned alkyl (meth) acrylate having 4 to 12 carbon atoms, a polymerizable monomer having a crosslinkable functional group in the side chain, or other monomers is usually (93 to 99.5) :( 0.5 to 2) :( 0 to 5) Is preferred.

"0" in the above composition ratio indicates that the component is not included.

When the ratio of the alkyl (meth) acrylate having 4 to 12 carbon atoms is less than 93, the adhesive force is insufficient, and when it exceeds 99.5, the cohesive force is lowered. If the proportion of the polymerizable monomer having a crosslinkable functional group in the side chain is less than 0.5, the durability will be lowered, and if it exceeds 2, the re-peelability will be lowered. In other words, when the acid value of the acrylate copolymer of the present invention is less than 1.5, it is difficult to secure durability by reducing the stress of the pressure-sensitive adhesive, and when the acid value exceeds 2.5, it is difficult to secure re-peelability due to an increase in adhesive force. . Moreover, when the ratio of another monomer exceeds 5, adhesive force falls.

Specifically, the above-mentioned contents related to re-peelability have been recently described, and the size of the adhesive force, which was not a problem in the past due to the enlargement of the liquid crystal panel, has recently been a problem. It is known to be a problem in terms of workability).

A well-known crosslinking agent can be added to the adhesive composition of this invention in order to strengthen cohesion force. As this crosslinking agent, a melamine derivative, for example, hexametholol melamine, hexamethoxymethyl melamine, hexabutoxymethyl melamine, etc .; Polyisocyanate compounds such as tolylene diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, diisocyanate compounds such as 2,4- or 4,4-diphenylmethane diisocyanate, and trimethyrolpropane of diisocyanate Adducts to polyhydric alcohol compounds, such as these; Or polyepoxy compounds such as bisphenol A and epichlorohydrin condensed epoxy compounds, polyglycidyl ethers of polyoxyalkylene polyols, glycerin di- or triglycidyl ethers, tetraglycidyl xylenediamines, and the like. Although it is preferable, it is preferable to use polyisocyanate or a polyepoxy compound. Said crosslinking agent can use together 1 type (s) or 2 or more types.

It is preferable to use 0.5-2 weight part with respect to 100 weight part of acrylate copolymer solids which have a crosslinkable functional group in a side chain, and the crosslinking agent contained in the adhesive composition of this invention is used more preferably 0.8-1.5 weight part. If it exceeds 2 parts by weight, it is difficult to secure durability due to the small adhesive strength, and if it is less than 0.5 parts by weight, the internal stress is small and the adhesive strength increases, making it difficult to secure durability and re-peelability and cutability.

A well-known silane coupling agent can be added to the adhesive composition of this invention. As this silane coupling agent, the silane coupling agent containing an epoxy group is preferable, For example, gamma glycidoxy propyl trimethoxysilane can be used. Epoxy groups in these molecules are bonded to the reactive functional groups of the polymer, and the alkoxysilane moiety is strongly bonded to the glass substrate of the liquid crystal cell, thereby connecting the pressure-sensitive adhesive and the liquid crystal cell, thereby improving adhesion stability and further improving heat and moisture resistance characteristics. Especially when it is left for a long time under high temperature and high humidity, it helps to improve adhesion reliability. In addition, preferably, oligomer-type silane coupling agents may be used, which suppresses the change of adhesion with the glass substrate over time and has the advantage of easy durability.

The content of the silane coupling agent is preferably used in an amount of 0.01 to 1 part by weight based on 100 parts by weight of an acrylate copolymer solid content having a crosslinkable functional group in the side chain. If the content of the silane coupling agent is less than 0.01 part by weight, the adhesive strength with the cell is weak. When 1 weight part is exceeded, there exists a problem that rework property is bad.

In the pressure-sensitive adhesive composition of the present invention, lithium bis (trifluoromethanesulfonyl) imide is used as an antistatic substance and is added in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of an acrylate copolymer solid having a crosslinkable functional group in the side chain. Preferably, it may be added more preferably 0.1 to 1 parts by weight. When lithium bis (trifluoromethanesulfonyl) imide is added in excess of 10 parts by weight, it is difficult to secure the original properties of the pressure-sensitive adhesive such as durability of the pressure-sensitive adhesive, and when added in less than 0.01 parts by weight, the original properties of the pressure-sensitive adhesive are reproduced. Although easy to do, it is difficult to secure sufficient antistatic performance.

In this invention, the manufacturing method of the alkyl (meth) acrylate type copolymer which has a crosslinkable functional group in a side chain is well-known superposition | polymerization by well-known superposition | polymerization method (block polymerization, solution polymerization, emulsion polymerization, suspension polymerization, etc.). Initiators (azo-based polymerization initiators such as azobisisobutyronitrile and azobisisovaleronitrile; peroxide-based polymerization initiators such as benzoyl peroxide, di-t-butyl peroxide, and lauryl peroxide), and the like Although it can be prepared using a chain transfer agent (mercapto group-containing chain transfer agent) and the like, preferably prepared by solution polymerization method, the molecular weight of the copolymer is weight average molecular weight (polystyrene) by gel gel permeation chromatography (GPC) method In terms of conversion), it is usually 50,000 to 2,000,000, preferably 100,000 to 1,800,000, more preferably 500,000 to 1,500,000.

The adhesive composition of this invention can mix | blend well-known various additives in the range which does not reduce the function aimed at by this invention, such as antistatic property, durability, re-peelability, and adhesive characteristics.

 Examples of the additives include tackifying resins [such as rosin, rosin derivatives or hydrogenated compounds thereof, polyterpene resins, terpene phenol resins, xylene resins, styrene resins, coumarone-indene resins, C5 petroleum resins, C9 petroleum resins, Etc.], plasticizers [carboxylic acid esters represented by phthalic acid esters, chlorinated paraffins, etc.], ultraviolet light inhibitors [benzophenone ultraviolet light inhibitors, etc.], mildew agents [copper oxide, phenolic compounds and the like], antifoaming agents [alcohols, silicone compounds, etc.] Etc.] etc. are mentioned.

The adhesive composition of this invention can be apply | coated directly to a base material or by a transfer method using a normal coating apparatus. In the case of direct coating, a polymer of triacetyl cellulose or a cyclic olefin used as a protective film of a polarizing plate can be used as a base material, and a base material which can be used when applying by a transfer method is polyethylene, polypropylene, polyethylene terephthalate, soft Silicone or fluorinated release film can be used for films of various plastics such as polyvinyl chloride, resin plates and the like, but it is preferable to use a silicon release-treated substrate on polyethylene terephthalate.

After coating and drying, if necessary curing (approximately 14 days), the curing is completely cured by the crosslinking reaction between the crosslinking agent and the polymer, thereby exhibiting sufficient adhesion characteristics. Curing conditions, for example, usually proceed for 10 to 20 days at room temperature and 3 to 6 days at 40 to 50 ° C, and can be cured under more severe temperature conditions to shorten the curing time.

The adhesive composition of this invention is not only an adhesive for polarizing plates, but a tape for electrical and electronic component processing, such as a carrier tape; Surface protection tapes such as stainless steel sheet and plastic sheet; Or adhesives such as sheets, mats, adhesive labels, stickers, tapes, and the like.

The present invention also provides a polarizing plate including an adhesive layer formed of the pressure-sensitive adhesive composition and a liquid crystal display device including the polarizing plate.

The polarizing plate has a structure in which a protective film is laminated on one or both sides of a polarizer (polarizing film). The protective film and polarizer (polarizing film) which comprise a polarizing plate are not specifically limited.

As an example of the said polarizer, the film etc. which were obtained by extending | stretching and containing polarizing components, such as iodine or a dichroic dye, in the film which consists of polyvinyl alcohol-type resins are mentioned. The thickness of these polarizers is not particularly limited and can form a conventional thickness. As the polyvinyl alcohol-based resin, polyvinyl alcohol, polyvinyl formal, polyvinyl acetal and ethylene, saponified vinyl acetate copolymer, and the like may be used.

Cellulose-based films such as triacetyl cellulose on one or both surfaces of the polarizer; Polyester films such as polycarbonate films and polyethylene terephthalates; Polyether sulfone-based film; Polyethylene, polypropylene, polyolefin-based films having a cyclo or norbornene structure; A protective film such as a polyolefin-based film such as ethylene-propylene copolymer may be laminated to form a multilayer film. At this time, the thickness of these protective films is also not particularly limited, and may form a conventional thickness.

The method for forming the pressure-sensitive adhesive layer on the polarizing plate in the present invention is not particularly limited, and the method of applying and drying the pressure-sensitive adhesive using a bar coater or the like directly on the surface of the polarizing plate, or applying the pressure-sensitive adhesive to the surface of the peelable substrate once and drying The method of transferring the adhesive layer formed on the surface of this peelable base material to the surface of a polarizing plate, and then aging can be applied.

In addition, the polarizing plate of the present invention may be laminated with one or more layers that provide additional functions such as a protective layer, a reflective layer, an antiglare layer, a retardation plate, a wide viewing angle compensation film, and a brightness enhancement film.

The polarizing plate to which the pressure-sensitive adhesive of the present invention is applied can be applied to all conventional liquid crystal display devices, and the kind of the liquid crystal panel is not particularly limited. Preferably, the present invention may comprise a liquid crystal display device including a liquid crystal panel obtained by bonding the pressure-sensitive adhesive polarizing plate to one side or both sides of a liquid crystal cell.

Hereinafter, the present invention will be described in more detail by production examples, examples and the like. However, the present invention is not limited to the examples and the like. Hereinafter, "part" shows a weight part and "%" shows the weight%.

Production Example  One: On the side chain Crosslinkable A functional group  Having Alkyl (meth) acrylate type  Preparation of Copolymer

A 4-neck jacketed reactor (1L) was equipped with a stirrer, a thermometer, a reflux condenser, a dropping lot, and a nitrogen gas inlet tube, 164 parts by weight of ethyl acetate, 136 parts by weight of n-butyl acrylate, and 0.6 weight of acrylic acid. 0.7 parts by weight of # 2-hydroxyethylacrylic acid was added to increase the external temperature of the reactor to 50 ° C. To 10 parts by weight of ethyl acetate was added dropwise a solution in which 0.14 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) was completely dissolved. After the reaction was continued for 5 hours while maintaining the jacket outside temperature at 50 ° C, 90 parts by weight of ethyl acetate was slowly added dropwise using the dropping lot for 1 hour. Furthermore, after 6 hours of additional stirring at the same temperature, 304 parts by weight of ethyl acetate was added, followed by stirring for another 2 hours, 20% by weight of solid content, a weight average molecular weight (in terms of polystyrene) of GPC method of 1,350,000, and an acid value of alkyl of 1.96. A (meth) acrylate copolymer was obtained.

Production Example  2: On the side chain Crosslinkable A functional group  Having Alkyl (meth) acrylate type  Preparation of Copolymer

Proceed in the same manner as in Preparation Example 1, except that the content of acrylic acid and 2-hydroxyethyl acrylic acid was changed to 0.4 parts by weight of acrylic acid and 0.6 parts by weight of # 2-hydroxyethyl acrylic acid, and the solid content concentration was 20% by weight in the GPC method. The weight average molecular weight (polystyrene @ conversion) by 1.3 million and the alkyl (meth) acrylate type copolymer of acid value 1.52 were obtained.

Production Example  3: On the side chain Crosslinkable A functional group  Having Alkyl (meth) acrylate type  Preparation of Copolymer

Proceed in the same manner as in Preparation Example 1, except that the content of acrylic acid and 2-hydroxyethyl acrylic acid was changed to 0.2 parts by weight of acrylic acid and 1.5 parts by weight of # 2-hydroxyethyl acrylic acid, and the solid content concentration was 20% by weight in the GPC method. The weight average molecular weight (polystyrene @ conversion) by 1,350,000 and the acid value 2.35 alkyl (meth) acrylate type copolymer were obtained.

Production Example  4: On the side chain Crosslinkable A functional group  Having Alkyl (meth) acrylate type  Preparation of Copolymer

The procedure was the same as in Production Example 1, except that the content of acrylic acid and 2-hydroxyethyl acrylic acid was changed to 3 parts by weight of acrylic acid and 2 parts by weight of 2-hydroxyethyl acrylic acid. The weight average molecular weight (polystyrene @ conversion) by 1,120,000 and the alkyl (meth) acrylate type copolymer of acid value 7.7 were obtained.

Production Example  5: On the side chain Crosslinkable A functional group  Having Alkyl (meth) acrylate type  Preparation of Copolymer

Proceed in the same manner as in Preparation Example 1, except that the content of acrylic acid and 2-hydroxyethyl acrylic acid was changed to 0.1 part by weight of acrylic acid and 0.4 part by weight of 2-hydroxyethyl acrylic acid, and the solid content concentration was 20% by weight in the GPC method. The weight average molecular weight (polystyrene @ conversion) by 1.4 million and the alkyl (meth) acrylate type copolymer of the acid value 0.84 were obtained.

Production Example  6: On the side chain Crosslinkable A functional group  Having Alkyl (meth) acrylate type  Preparation of Copolymer

The procedure of Production Example 1 was repeated except that the contents of acrylic acid and 2-hydroxyethyl acrylic acid were changed to 0.33 parts by weight of acrylic acid and 0.53 parts by weight of 2-hydroxyethyl acrylic acid. The weight average molecular weight (polystyrene @ conversion) by 1.3 million and the acid value 1.32 alkyl (meth) acrylate type copolymer were obtained.

Production Example  7: On the side chain Crosslinkable A functional group  Having Alkyl (meth) acrylate type  Preparation of Copolymer

The procedure was the same as in Production Example 1, except that the contents of acrylic acid and 2-hydroxyethyl acrylic acid were changed to 0.23 parts by weight of acrylic acid and 1.7 parts by weight of 2-hydroxyethyl acrylic acid, and the solid content concentration was 20% by weight in the GPC method. The weight average molecular weight (polystyrene @ conversion) by 1.3 million and the acid value 2.66 alkyl (meth) acrylate type copolymer were obtained.

Example  1: Preparation of Antistatic Adhesive Composition

To 100 parts by weight of the copolymer prepared in Production Example 1 (solid content ratio), 0.1 part by weight of N, N, N'N'-tetraglycidyl xylenediamine [TETRAD-X, Mitsubishi Chemical Company] as a crosslinking agent 1 part by weight of Nate-L [manufactured by Japan Polyurethane Industry Co., Ltd.], 0.1 part by weight of gamma glycidoxypropyl trimethoxysilane (KBM-403, manufactured by Shin-Etsu Co., Ltd.) as a silane coupling agent, and lithium bis (trifluoro) as a conductive material. 5 parts by weight of methanesulfonyl) imide (3M, HQ-115) was added thereto, followed by stirring for 10 minutes to prepare a uniform mixed solution. This was dried on two PET films (25cm X 20cm) coated with a release agent using an applicator and then coated to have a thickness of 25 microns, respectively, and 100 ° C. The oven was dried in a forced hot air dryer for 3 minutes. One sample was obtained by laminating another release film on the pressure-sensitive adhesive layer to obtain a pressure-sensitive adhesive layer in the form of a non-carrier film (NCF) and stored in a thermo-hygrostat (60%, 25 ° C.) for gel fraction analysis. The other sheet was adhered to the polarizing plate as in the following <plywood process> to evaluate the durability.

Example  2: Preparation of Antistatic Adhesive Composition

It proceeded similarly to Example 1 except having used 2 weight part of lithium bis (trifluoromethanesulfonyl) imide (3M company, HQ-115).

Example  3: Preparation of Antistatic Adhesive Composition

The procedure was the same as in Example 1 except that 1 part by weight of lithium bis (trifluoromethanesulfonyl) imide (3M, HQ-115) was used.

Example  4: Preparation of Antistatic Adhesive Composition

The procedure was the same as in Example 1 except that 0.5 parts by weight of lithium bis (trifluoromethanesulfonyl) imide (3M, HQ-115) was used.

Example  5: Preparation of Antistatic Adhesive Composition

The procedure was the same as in Example 1 except that 0.2 parts by weight of lithium bis (trifluoromethanesulfonyl) imide (3M, HQ-115) was used.

Example  6: Preparation of antistatic adhesive composition

It proceeded similarly to Example 1 except having used 0.1 weight part of lithium bis (trifluoromethanesulfonyl) imide (3M company, HQ-115).

Example  7: Preparation of antistatic adhesive composition

The procedure was the same as in Example 1 except that 1 part by weight of lithium bis (trifluoromethanesulfonyl) imide (3M, HQ-115) was used and the polymer prepared in Preparation Example 2 was used.

Example  8: Preparation of Antistatic Adhesive Composition

The procedure was the same as in Example 1 except that 1 part by weight of lithium bis (trifluoromethanesulfonyl) imide (3M, HQ-115) was used and the polymer prepared in Preparation Example 3 was used.

Comparative example  1: Preparation of Antistatic Adhesive Composition

The procedure was the same as in Example 1 except that 1 part by weight of lithium bis (trifluoromethanesulfonyl) imide (3M, HQ-115) was used and the polymer prepared in Preparation Example 4 was used.

Comparative example  2: Preparation of Antistatic Adhesive Composition

The procedure was the same as in Example 1 except that 1 part by weight of lithium bis (trifluoromethanesulfonyl) imide (3M, HQ-115) was used and the polymer prepared in Preparation Example 5 was used.

Comparative example  3: Preparation of Antistatic Adhesive Composition

The procedure was the same as in Example 1 except that 1 part by weight of lithium bis (trifluoromethanesulfonyl) imide (3M, HQ-115) was used and the polymer prepared in Preparation Example 6 was used.

Comparative example  4: Preparation of Antistatic Adhesive Composition

The procedure was the same as in Example 1 except that 1 part by weight of lithium bis (trifluoromethanesulfonyl) imide (3M, HQ-115) was used and the polymer prepared in Preparation Example 7 was used.

Test Example

< Polymer  Acid value measurement>

A mixed solvent [toluene / IPA / DI = 50 / 49.5 / 0.5 (weight ratio) using a Metrohm 736GP titrino instrument and a nonaqueous solvorodde (Ag. Ag / AgCl) electrode )], The polymer was dissolved, titrated using a 0.1 N KOH titration solution in ethanol, and calculated using the following formula, and is shown in Table 1 below.

formula:

Acid value = {(titration of sample-titration of blank) * factor * 5.611} / weight of sample

< NCF Gel% Analysis of Mold Adhesive>

The NCF prepared above was stored at room temperature for 14 days, and then cut to an appropriate size to measure the weight, immersed in ethyl acetate solvent, stored at room temperature for 48 hours, dried at 60 ° C. in a vacuum oven for 2 hours, and then the difference in weight was measured. The gel fraction was measured from the difference and shown in Table 2 below.

<Plywood process>

The pressure-sensitive adhesive layer prepared above was adhered to an iodine polarizer having a thickness of 185 microns, and stored in a thermo-hygrostat (60%, 25 ^° C.). The obtained polarizing plate was cut | disconnected to the appropriate magnitude | size, and was used for evaluation.

< Durability Reliability  Evaluation>

The pressure-sensitive adhesive coated polarizing plate (250mm> 200mm) prepared above was cut into a size of a glass substrate (200mm>200mm> 0.7mm) and attached to both sides of the glass substrate in a state where the optical absorption axis of the polarizing plate was crossed. At this time, the pressure applied was about 5kg / cm ² and the clean room operation was performed so that no bubbles or foreign substances were generated.

(One) Moisture and Heat Resistance

In order to determine the heat and humidity characteristics of the specimens, the mixture was left at 60 ° C. and 90% relative humidity for 500 hours, and then observed whether bubbles or peeling occurred.

(2) heat resistance

The heat resistance characteristics are shown in Table 2 below after observing the bubble or peeling after leaving at 80 ℃, 500 hours. Immediately after evaluating the state of the specimen was performed at room temperature for 24 hours. The evaluation criteria for reliability are as follows.

О: No bubbles or peeling

△: bubble or peeling phenomenon

X: Many bubbles or peeling phenomenon

<Surface resistance measurement>

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

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

-Measuring method: Measure the three places of the surface 10 times and take the average value.

Surface resistance values measured by the above method are shown in Table 2 below.

<Measurement of adhesion force>

Using a super cutter, cut to size (25mm wide, 250mm long), and use Corning Glass (size: 200mm x 120mm, thickness: 0.7mm) to make a sample number n = 3, and then apply 50% x 490pa The autoclave treatment was carried out on the conditions of x 20 minutes, and after standing at 23 ° C. for one day, the adhesive force was measured using an autograph equipment. The measured values are shown in Table 2 below.

Preparation Example 1 Preparation Example 2 Preparation Example 3 Preparation Example 4 Preparation Example 5 Preparation Example 6 Preparation Example 7 BA weight 136 136 136 136 136 136 136 AA weight 0.6 0.4 0.2 3.0 0.1 0.33 0.23 2-HEA weight 0.7 0.6 1.5 2.0 0.4 0.53 1.70 Molecular Weight 1.35 million 1.3 million 1.35 million 127 million 1.4 million 1.3 million 1.3 million Acid 1.96 1.52 2.35 7.7 0.84 1.32 2.66

* AA: acrylic acid, BA: n-butyl acrylate, 2-HEA: 2-hydroxyethyl acrylic acid

Copolymer Copolymer acid number HQ-115 (part by weight) Gel fraction (%) Adhesion (N / inch) Surface resistivity (Ω / □) Heat Resistance / Moisture Heat Resistance Example 1 Preparation Example 1 1.96 5 55 7.31 3.4X10 ^ 9 О / О Example 2 Preparation Example 1 1.96 2 63 6.5 4.21X10 ^ 10 О / О Example 3 Preparation Example 1 1.96 One 70 4.5 1.1X10 ^ 11 О / О Example 4 Preparation Example 1 1.96 0.5 73 4.0 2.1X10 ^ 11 О / О Example 5 Preparation Example 1 1.96 0.2 75 3.5 3.7X10 ^ 11 О / О Example 6 Preparation Example 1 1.96 0.1 75 3.5 8.2X10 ^ 11 О / О Example 7 Preparation Example 2 1.52 One 55 3.0 1.3X10 ^ 11 О / О Example 8 Preparation Example 3 2.35 One 82 7.0 2.1X10 ^ 11 О / О Comparative Example 1 Preparation Example 4 7.7 One 85 25 1.7X10 ^ 11 О / О Comparative Example 2 Preparation Example 5 0.84 One 65 1.5 1.5X10 ^ 11 X / X Comparative Example 3 Preparation Example 6 1.32 One 51 2.7 1.7X10 ^ 11 Δ / Δ Comparative Example 4 Preparation Example 7 2.66 One 84 10.1 1.7X10 ^ 11 О / О

As shown in Table 1 and Table 2, in the case of an antistatic pressure-sensitive adhesive composition using an acrylate-based copolymer (Production Examples 4 and 7) having an acid value of more than 2.5, since the adhesive force is 10 N / inch or more, In the case of the antistatic pressure-sensitive adhesive composition using an acrylate copolymer (Preparation Examples 5 and 6) having an acid value of less than 1.5, there is a problem in terms of durability and durability due to problems in heat resistance and moisture resistance. It was.

The present invention can provide an antistatic pressure-sensitive adhesive composition, a polarizing plate and a liquid crystal display using the same, which ensures durability, re-peelability, and antistatic property at the same time.

Claims (6)

An acid value of an acrylate copolymer having a crosslinkable functional group in the side chain, a crosslinking agent, a silane coupling agent, and lithium bis (trifluoromethanesulfonyl) imide, wherein the acid value of the acrylate copolymer having a crosslinkable functional group in the side chain Antistatic adhesive composition of 1.5-2.5.  The method according to claim 1, 0.5 to 2 parts by weight of the crosslinking agent, 0.01 to 1 part by weight of the silane coupling agent, and lithium bis (trifluoromethanesulfonyl) based on 100 parts by weight of the acrylate copolymer solid content having a crosslinkable functional group in the side chain. ) Antistatic pressure-sensitive adhesive composition comprising 0.01 to 10 parts by weight of imide. The acrylic copolymer of claim 1, wherein the acrylic copolymer having a crosslinkable functional group in the side chain Alkyl (meth) acrylate monomers having 4 to 12 carbon atoms; A polymerizable monomer having a crosslinkable functional group in a side chain selected from the group consisting of a polymerizable monomer having a carboxylic acid group, a polymerizable monomer having a hydroxyl group, a polymerizable monomer having an amide group and a polymerizable monomer having a tertiary amine group; And C1-C3 alkyl (meth) acrylate monomers, C3-C18 alkyl (meth) acrylate monomers, (meth) acrylic acid ester monomers derived from cyclic alcohols, (meth) acrylate monomers derived from aromatic alcohols At least one monomer selected from the group consisting of an aromatic monomer, an allyl compound monomer, a monomer having a nitrile group, a halogen-containing monomer, a vinyl ester monomer, and a vinyl ether monomer (93 to 99.5): (0.5 to 2): It is an alkyl (meth) acrylate type copolymer containing in the weight ratio of (0-5), The antistatic adhesive composition characterized by the above-mentioned. The antistatic adhesive composition according to claim 1, wherein the crosslinking agent is at least one member selected from the group consisting of melamine derivatives, polyisocyanate compounds, and polyepoxy compounds. The polarizing plate containing the adhesion layer formed from the antistatic adhesive composition of any one of Claims 1-4. Liquid crystal display comprising the polarizing plate of claim 5.