KR20120072162A - Adhesive composition and optical member using the same - Google Patents

Abstract

PURPOSE: An adhesive is provided to have excellent antistatic performance, maintaining existing excellent light leaking, and to have physical property balance of adhesion, antistatic property, durability, transparence, and light leaking property. CONSTITUTION: An adhesive has the surface resistance of 10^8 - 10^12 angstrom/sq, and difference in brightness(ΔL) between an edge part and a center part by formula of ΔL = [(a+b+d+e)/4]-c is higher than 0, or less than 1. In formula, a, b, d, and e is average luminance on site corresponding the 1/16 of total surface from an end part of each side of an optical element, and c is average luminance of 1/32 of the surface of a center part in the optical element.

Description

Adhesive and Optical Member Using The Same {Adhesive Composition and Optical Member Using the Same}

The present invention relates to an adhesive and an optical member using the same. More specifically, the present invention relates to an improved adhesive and an optical member using the same, while maintaining excellent productivity and light leakage, which are existing advantages of the hard type adhesive, while maintaining transparency, durability, and antistatic function.

Optical films include polarizing plates, color filters, retardation films, elliptical polarizing films, reflective films, antireflection films, compensation films, brightness enhancement films, alignment films, light diffusion films, glass scattering prevention films, surface protection films, and plastic LCD substrates. These are used for various optical members, including a liquid crystal display device.

When laminating | stacking optical members, such as a polarizing plate and retardation plate, on a liquid crystal cell and manufacturing a liquid crystal display, the method of bonding through an adhesive layer is used preferably. Since a peeling film or an optical member is comprised by the plastic material with high electrical insulation in many cases, static electricity generate | occur | produces when it joins or peels off. In particular, the static electricity generated by the peeling is called a peeling electrification voltage and has been a serious problem. It is because the adhesive sheet charged by the static electricity which generate | occur | produced generate | occur | produced a defect by foreign material adhering to the surrounding. Moreover, when the adhesive sheet is affixed on a liquid crystal cell in the state which the static electricity which generate | occur | produced at this time remains, the problem that the orientation of a liquid crystal molecule arises is also pointed out. In solving such a problem, it is desired to provide antistatic property to the pressure-sensitive adhesive layer as a countermeasure against static electricity.

KR 2010-0093470 discloses an adhesive comprising a lithium salt type antistatic agent as an antistatic agent. In addition, KR 2010-0067171 discloses an antistatic adhesive comprising a pyridinium salt type antistatic agent, and KR 2010-0093470 refers to a technique for increasing the effect of a lithium salt antistatic agent by applying an ester copolymer. KR 2009-0075360 also discloses a technique for introducing an antistatic coating layer between an adhesive and a release film surface.

However, the conventional antistatic agent has a problem that the transparency is lowered or light leakage occurs even if the antistatic performance can be imparted, or the durability is lowered, thereby deteriorating the performance of the adhesive.

In the case of a pressure-sensitive adhesive for a polarizing plate, durability is required in which various processes such as manufacturing of liquid crystal displays, transportation at the time of sale, long-term use, and the like do not cause exfoliation, and in addition to dimensional changes such as shrinkage and expansion of a film. There is a need for a pressure sensitive adhesive sheet having a pressure sensitive adhesive layer that is resistant to light leakage (light leakage) generated by the accompanying stress change.

As a typical representative method for resolving light leakage, KR 1998-0079266 discloses a method for securing stress relaxation by designing a pressure-sensitive adhesive to a soft type that has a large creep to external stress and is easily deformed. However, in the case of the soft type pressure-sensitive adhesive, the pressing property or the squeezing phenomenon occurs in the manufacturing process of the polarizing plate, the productivity and yield are greatly reduced.

Another method for preventing light leakage is to reversely design the adhesive hard. When the adhesive is designed to have hard properties, the polarizing plate can be minimized under high temperature or high humidity conditions to minimize the occurrence of stress, and to concentrate on the outermost surface to achieve fair optical properties while achieving relatively excellent optical properties. Can be. However, according to the storage modulus (G ') of the polarizing plate hard type adhesive, there is a disadvantage that the initial adhesive strength is lowered, thereby the durability is greatly reduced, especially when the shrinkage of the polarizing film is large, this phenomenon is intensified.

One object of the present invention is to provide an adhesive having excellent chargeability while maintaining the existing excellent light leakage.

Another object of the present invention is to provide an adhesive having balance between adhesion, antistatic property, durability, transparency, and light leakage.

Still another object of the present invention is to provide an adhesive having excellent creep properties.

Another object of the present invention is to provide a pressure sensitive adhesive which is particularly suitable for hard type pressure sensitive adhesives.

Still another object of the present invention is to provide an optical member having excellent balance of physical properties such as creep property, peel strength, durability, rework and cutting property by using the pressure-sensitive adhesive.

One aspect of the present invention relates to an adhesive. In one embodiment, the pressure-sensitive adhesive is characterized in that the surface resistance is 10 ⁸ to 10 ¹² Ω / sq, and the luminance difference ΔL between the edge portion and the center portion by the following formula is greater than 0 and less than 1:

ΔL = [(a + b + d + e) / 4] -c

(A, b, d, e in the above is the average of the luminance of the position corresponding to the area of 1/16 of the total area from the edge of each side of the optical member, c is the average luminance of the area 1/32 of the center of the optical member) .

In another embodiment, the pressure-sensitive adhesive may include an alkylammonium compound represented by Formula 1 below:

[Formula 1]

(Wherein n is an integer from 0 to 15).

The pressure-sensitive adhesive may be an initial adhesive strength of 100 to 250 gf measured by a tensile tester (Texture Analyzer) after adhesion for 2 seconds to the adhesive surface.

In an embodiment, the pressure-sensitive adhesive may be attached to a glass plate and left for 3 days, and a creep distance measured by a tensile analyzer may be 1 to 50 μm.

In some embodiments, the pressure-sensitive adhesive may have a haze of 0 to 0.1%.

In an embodiment, the pressure-sensitive adhesive may include a (meth) acrylate copolymer, a crosslinking agent, and the alkylammonium compound.

In an embodiment, the pressure-sensitive adhesive may include 100 parts by weight of the (meth) acrylate copolymer, 0.01 to 10 parts by weight of the crosslinking agent, and 0.01 to 10 parts by weight of the alkylammonium compound.

In an embodiment, the (meth) acrylate copolymer may have a carboxyl group and a hydroxyl group.

In embodiments, the (meth) acrylate-based copolymer may be a copolymer of an alkyl (meth) acrylate of C1-16 and a monomer having a carboxyl group and a monomer having a hydroxy group.

In embodiments, the (meth) acrylate copolymer may have a weight average molecular weight of 1,000,000 to 1,500,000 g / mol.

In embodiments, the crosslinking agent may be a combination of an isocyanate-based and carbodiimide-based.

The pressure-sensitive adhesive may further comprise 0.01 to 3 parts by weight of a silane coupling agent.

Another aspect of the invention relates to an optical member. In an embodiment the optical member is characterized in that it comprises the pressure-sensitive adhesive layer of one side or both sides of the optical film. In an embodiment, the optical member may be a polarizing film or a retardation film.

The present invention has excellent chargeability while maintaining the existing excellent light leakage, adhesion, antistatic properties, durability, transparency and balance of light leakage properties, excellent creep (CREEP) properties, adhesives particularly suitable for hard type adhesives Has the effect of providing. In addition, the present invention has the effect of providing an optical member having excellent balance of physical properties such as creep property, peel strength, durability, rework and cutting properties using the pressure-sensitive adhesive.

The pressure-sensitive adhesive of the present invention includes an alkylammonium compound represented by Formula 1 below:

[Formula 1]

(Wherein n is an integer from 0 to 15).

In the case of applying the alkylammonium compound having the above structure, the adhesive is charged with an antistatic property and not only has an antistatic function, but also has good compatibility with the acrylic adhesive, so that the adhesive is uniformly dispersed between the polymer networks after the adhesive is cured. Transparency can be maintained. In addition, since it does not contain functional groups, it does not chemically react with the adhesive network, so that the existing structure of the acrylic adhesive remains the same, but acts like a low molecular polymer between the polymer networks, thereby increasing the initial adhesive strength of the adhesive and providing flexibility, which is advantageous in durability. It can work.

In Formula 1, n is an integer of 0 to 15, preferably an integer of 0 to 7.

The alkylammonium compound may be included in an amount of 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, and more preferably 0.5 to 3.5 parts by weight, based on 100 parts by weight of the (meth) acrylate copolymer. It may have an antistatic, compatibility, transparency and adhesive physical property balance in the above range.

In an embodiment, the pressure-sensitive adhesive may include a (meth) acrylate copolymer and a crosslinking agent together with the alkylammonium compound.

The (meth) acrylate copolymer may be applied to all of the conventional (meth) acrylate copolymer. In an embodiment it is polymerized from a monomer mixture comprising a C 1-20 alkyl (meth) acrylate and a monomer copolymerizable therewith.

Examples of the alkyl (meth) acrylate of C1-20 include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, and hexyl ( Meta) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, and the like. It is not necessarily limited thereto. These can be applied individually or in mixture of 2 or more types. Here (meth) acrylate means both acrylate and methacrylate.

The copolymerizable monomer may be a monomer having a hydroxy group, a monomer having a carboxyl group, a monomer having a positive birefringence, and the like.

For example, the (meth) acrylate copolymer may be a copolymer of an alkyl (meth) acrylate of C1-16, a monomer having a carboxyl group, and a monomer having a hydroxy group. In embodiments, the monomer having a carboxyl group and the monomer having a hydroxy group may be included in an amount of 0.01 to 10% by weight of the total copolymer.

In another embodiment, the (meth) acrylate copolymer may include a C1-20 alkyl (meth) acrylate, a monomer having a hydroxy group, a monomer having a carboxyl group, and a monomer having a positive birefringence. In an embodiment, the (meth) acrylate copolymer may include 60 to 99% by weight of alkyl (meth) acrylate of C1-20, 0.01 to 20% by weight of monomer having a hydroxy group, 0.01 to 10% by weight of monomer having a carboxyl group and an amount thereof. It may include 0 to 10% by weight of a monomer having a birefringence of.

Examples of the monomer having a hydroxy group include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth) acryl Latex, 6-hydroxyhexyl (meth) acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate, chloro-2-hydroxypropyl acrylate, diethylene glycol mono (meth) acrylate, allyl alcohol Etc., but are not necessarily limited thereto. These can be applied individually or in mixture of 2 or more types.

Examples of the monomer having a carboxyl group include (meth) acrylic acid, 2-carboxyethyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, 4-carboxybutyl (meth) acrylate, itaconic acid, crotonic acid, male Acids, fumaric acid and maleic anhydride, and the like, but are not necessarily limited thereto. These can be applied individually or in mixture of 2 or more types.

 Monomers having such birefringence may comprise aromatic (meth) acrylates. Specific examples include cyclohexyl (meth) acrylate, 2-ethylphenoxy (meth) acrylate, 2-ethylthiophenyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, 2-phenyl Ethyl (meth) acrylate, 3-phenylpropyl (meth) acrylate, 4-phenylbutyl (meth) acrylate, 2-2-methylphenylethyl (meth) acrylate, 2-3-methylphenylethyl (meth) acrylate , 2-4-methylphenylethyl (meth) acrylate, 2- (4-propylphenyl) ethyl (meth) acrylate, 2- (4- (1-methylethyl) phenyl) ethyl (meth) acrylate, 2- (4-methoxyphenyl) ethyl (meth) acrylate, 2- (4-cyclohexylphenyl) ethyl (meth) acrylate, 2- (2-chlorophenyl) ethyl (meth) acrylate, 2- (3- To chlorophenyl) ethyl (meth) acrylate, 2- (4-chlorophenyl) ethyl (meth) acrylate, 2- (4-bromophenyl) ethyl (meth) acrylate, 2- (3-phenylphenyl) (Meth) acrylate and the like, and 2- (4-benzylphenyl) ethyl (meth) acrylate, such as methacrylic acid, but are not necessarily limited thereto. These may be used alone or in combination of two or more.

The (meth) acrylate copolymer may have a weight average molecular weight of 1,000,000 to 1,500,000 g / mol. Preferably 1,200,000 to 1,450,000 g / mol.

Isocyanate-based, epoxy-based, imide-based, aziridine-based, etc. may be used as the crosslinking agent, but is not limited thereto. These may be used alone or in combination of two or more.

Examples of the isocyanate-based crosslinking agent include toluene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isoform diisocyanate, tetramethyl xylene diisocyanate, naphthalene diisocyanate, and polyols such as trimethylolpropane. Etc., but are not necessarily limited thereto. These can be applied individually or in mixture of 2 or more types.

As said epoxy crosslinking agent, ethylene glycol diglycidyl ether, triglycidyl ether, trimethylol propane triglycidyl ether, N, N, N'N'- tetraglycidyl ethylenediamine, glycerin diglycidyl ether, etc. This is not necessarily the case. These can be applied individually or in mixture of 2 or more types.

Carbodiimide or the like may be used as the imide-based crosslinking agent.

In one embodiment, an isocyanate crosslinking agent and an epoxy crosslinking agent may be applied together. The ratio of the isocyanate crosslinking agent and the epoxy crosslinking agent is 1500: 1 to 1: 1, preferably 100: 1 to 10: 1. It is possible to obtain a better light leakage inhibitory effect in the above range.

In another embodiment, an isocyanate crosslinking agent and a carbodiimide crosslinking agent may be applied together. The ratio of the isocyanate crosslinking agent and the carbodiimide crosslinking agent is from 3500: 1 to 500: 1, preferably from 2500: 1 to 1000: 1. It is possible to obtain a better light leakage inhibitory effect in the above range.

In the present invention, the content of the crosslinking agent is applied in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the (meth) acrylate copolymer. Preferably it is 0.05-8.5 weight part. Light leakage improvement effect can be obtained in the said range.

In the present invention, in order to further improve adhesion stability and adhesion reliability, a conventional silane coupling agent may be applied.

Examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, and vinyl Trimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-aminopropyltriethoxysilane, 3-isocyanatepropyltriethoxysilane And γ-acetoacetatepropyltrimethoxysilane, and these can be applied alone or in combination of two or more thereof.

The silane coupling agent is applied in an amount of 0.01 to 3 parts by weight, preferably 0.05 to 0.3 parts by weight, based on 100 parts by weight of the (meth) acrylate copolymer. It may have an adhesive stability and adhesion reliability effects within the above range.

In addition, the pressure-sensitive adhesive of the present invention may optionally further include conventional additives such as ultraviolet stabilizer, antioxidant, colorant, reinforcing agent, antifoaming agent, surfactant, plasticizer.

The production method of the pressure-sensitive adhesive of the present invention can be prepared according to a conventional method. In an embodiment, the (meth) acrylate copolymer may be prepared by uniformly mixing an alkylammonium compound, a crosslinking agent, and an optional additive. At this time, a solvent can be added and diluted as needed. The mixing and dilution method can be easily carried out by those skilled in the art.

The pressure-sensitive adhesive of the present invention has excellent heat resistance, flexibility, peel strength and rework property, can achieve low light leakage, and particularly excellent antireflection performance.

The pressure-sensitive adhesive may be coated on an optical film and then aged to form a pressure-sensitive adhesive layer.

The pressure-sensitive adhesive of the present invention is 100 to 250 gf, preferably 120 to 250 gf, more preferably 150 to 250 gf after the ball probe is adhered to the adhesive surface for 2 seconds by an tensile tester (Texture Analyzer) Can be.

In addition, the pressure-sensitive adhesive has a surface resistance of 10 ⁸ to 10 ¹² dl / sq, preferably 10 ⁸ to 10 ¹¹ dl / sq, measured with Mitsubishi chemical MCP-HT450 for 10 seconds in an area of 100 mm × 100 mm, more preferably 10 ⁸ To 5 × 10 ¹⁰ μs / sq.

In addition, the pressure-sensitive adhesive is not visually strongly observed when measuring the light leakage visually, the luminance difference (ΔL) between the edge portion and the central portion by the following formula is more than 0 less than 1, preferably 0.5 or less, more preferably more than 0 It can be less than 0.2:

ΔL = [(a + b + d + e) / 4] -c

(A, b, d, e in the above is the average of the luminance of the position corresponding to the area of 1/16 of the total area from the edge of each side of the optical member, c is the average luminance of the area 1/32 of the center of the optical member) .

The adhesive may be attached to a glass plate and left for 3 days, and then the creep may be 1 to 50 µm, preferably 20 to 50 µm, and more preferably 40 to 50 µm, measured by a tensile tester (Texture Analyzer). have.

The adhesive may have a haze of 0.1% or less, preferably 0 to 0.08%, measured by a Hazemeter.

Another aspect of the invention relates to an optical member. The optical member may include the pressure-sensitive adhesive as an adhesive layer on one side or both sides of the optical film. In the present invention, a method of forming the pressure-sensitive adhesive layer on the optical film is not particularly limited, and the pressure-sensitive adhesive layer is directly applied to the surface of the optical film and dried, or the pressure-sensitive adhesive layer is formed on the surface of the peelable base material. A method of transferring can be used. The thickness of the pressure-sensitive adhesive layer may be formed from 10 to 100 ㎛, preferably 20 to 70 ㎛.

The optical film may include a polarizing plate, a color filter, a retardation film, an elliptical polarizing film, a reflection film, an antireflection film, a compensation film, a brightness enhancement film, an alignment film, a light diffusion film, a glass scattering prevention film, a surface protection film, a plastic LCD substrate, and the like. Can be mentioned. The manufacturing method of the optical film can be easily manufactured by those skilled in the art to which the present invention pertains.

Hereinafter, the present invention will be described in more detail with reference to examples, but these examples are for illustrative purposes only and should not be construed as limiting the present invention.

Example

(A) (meth) acrylate copolymer: containing 92.5% by weight of n-butyl acrylate, 2.5% by weight of acrylic acid and 5% by weight of hydroxyethyl methacrylate with a weight average molecular weight of 1 million and a solid content of 25 (Meth) acrylate type copolymer which is% was used.

(B) crosslinking agent

Trimetholpropane adducts of (B1) diisocyanate were used.

(B2) (V05: Nissin Bochemical) was used as an imide crosslinking agent.

(C) antistatic agent

(C1) Alkyl ammonium compound: In the formula (1) was used a compound of n is 4.

(C2) Pyridine antistatic agent: ILP14-2 (KOEI)

(C3) Lithium salt type antistatic agent: ILA2-2 (KOEI)

(D) Silane coupling agent: (gamma) -glycithoxy propyl methoxy silane (KBM-403: the product made by Shin-Yetsu Chemical Co., Ltd.) was used.

Examples 1-4

Each component was mixed in the composition shown in Table 1 below, 20 parts by weight of methyl ethyl ketone was added as a diluent, and stirred for 20 minutes to prepare an adhesive coating solution. The prepared pressure-coating solution was coated on a release film, and after drying, the pressure-sensitive adhesive layer was prepared so that the pressure-sensitive adhesive layer was 25 μm, and the properties of the pressure-sensitive adhesive were aged at 35 ° C. and 45%.

Comparative Example 1

The same procedure as in Example 1 was conducted except that no alkyl ammonium compound was added.

Comparative Example 2

The same procedure as in Example 2 was carried out except that a pyridine antistatic agent was added instead of the alkyl ammonium compound.

Comparative Example 3

The same procedure as in Example 2 was carried out except that a lithium salt antistatic agent was added instead of the alkyl ammonium compound.

Example Comparative example One 2 3 4 One 2 3 (A) 100 100 100 100 100 100 100 (B) (B1) 8.0 8.0 8.0 8.0 8.0 8.0 8.0 (B2) 0.003 0.003 0.003 0.003 0.003 0.003 0.003 (C) (C1) 0.6 0.9 1.2 1.5 - - - (C2) - - - - - 0.9 - (C3) - - - - - - 0.9 (D) 0.06 0.06 0.06 0.06 0.06 0.06 0.06

Property evaluation

(1) Initial adhesive force: After attaching the polarizing plate to the pressure-sensitive adhesive to the tensile analyzer (Texture Analyzer), the force was measured after adhering the ball probe to the adhesive surface for about 2 seconds and falling vertically (unit: gf).

(2) Peeling force (gf / 25 mm): 180 degree peeling strength between adhesive-glass substrate (Glass) was measured based on JIS2107 standard. The samples were cut into 25 mm × 210 mm sizes and laminated on the glass surface, and then each was measured using a tensile tester (Texture Analyzer) to measure the interfacial peel force between the adhesive layer and the glass surface at a speed of 300 mm / min.

(3) Creep: Creep was evaluated after 3 days at room temperature after attaching the polarizing plate to the glass plate with an adhesive area of 1.5 cm x 1.5 cm. Creep was measured using a tensile tester (Texture Analyzer) to pull the specimen with a force of 2kgf to measure the distance (㎛) the pressure-sensitive adhesive was pushed.

(4) Surface resistance (Ω / sq): After cutting the specimen into 100 mm x 100 mm in the polarizing plate, the adhesive surface resistance was measured for 10 seconds with Mitsubishi chemical MCP-HT450.

(5) Light leakage: (i) After attaching a polarizing plate to a liquid crystal display device, 250 hours was input at 70 degreeC, and it left for 1 hour at room temperature, and measured using the visual and luminance measuring device. When light leakage occurs, the luminance of the end portion is increased from the center portion of the liquid crystal display device so that the unevenness of brightness is observed.

○: no light leakage phenomenon.

×: light leakage phenomenon.

(Ii) After driving the liquid crystal display device, the luminance of the entire surface of the display panel was measured at a height of 1 m using a luminance measuring equipment (Lisa). The degree of light leakage was quantified through the difference in luminance between the center and the edge where light leakage appeared. The luminance difference ΔL between the edge portion and the center portion was obtained by the following equation, and the lower the ΔL value, the better the light leakage. When ΔL is less than 1, light leakage phenomenon is not observed in visual observation, but when ΔL is 1 or more, light leakage phenomenon is strongly recognized at a specific position or light leakage phenomenon is expressed in a wide range, thereby deteriorating luminance unifomity of the panel.

ΔL = [(a + b + d + e) / 4] -c

(A, b, d, e in the above is the average of the luminance of the position corresponding to the area of 1/16 of the total area from the edge of each side of the optical member, c is the average luminance of the area 1/32 of the center of the optical member) .

(6) Durability: The polarizing plate is attached to the liquid crystal display or glass at 100mm x 80mm, and then adhered at 50 ° C and 3.5 atmospheres. Thereafter, after 250 hours at 110 ℃ dry heat conditions, 250 hours at 60 ℃ / 90% moisture-resistant conditions and left at room temperature for 1 hour or more to check the presence / absence of pressure-sensitive adhesive lifting and bubble generation at the end of the polarizing plate.

(Circle): There is no edge lift and bubble generation.

(Triangle | delta): End edge lifting is carried out and there is an end bubble.

X: edge lift and bubble generation.

(7) Haze: It was measured by Hazemeter (HR-100).

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Initial cohesion (gf) 110 130 147 156 90 86 103 Peeling force (gf / 25mm) 370 380 370 385 270 285 280 Creep (μm) 43 45 43 45 40 84 44 Surface Resistance (Ω / sq) 6 x 10 ¹¹ 1 x 10 ¹¹ 5 x 10 ¹⁰ 3 x 10 ¹⁰ - 1 x 10 ¹¹ 3 x 10 ¹² Light fountain
(Visual / ΔL) ○ ○ ○ ○ ○ x ○ <0.1 <0.1 <0.1 <0.1 <0.1 1.2 <0.1 durability △ ○ ○ ○ X ○ X Haze (Δ%) <0.1 <0.1 <0.1 <0.1 <0.1 0.7 <0.1

As shown in Table 2, in the case of Examples 1 to 4 using the (C1) alkyl ammonium compound, there is no change in cohesion (creep) because it does not affect the main network of the pressure-sensitive adhesive. Therefore, it can be seen that the existing excellent light leakage is maintained. In addition, it can be seen that the chargeability and the initial adhesive strength were increased according to the addition content of the (C1) alkyl ammonium compound. In addition, as the (C1) alkyl ammonium compound including the soft chain is added, it can be seen that durability is improved.

On the other hand, in the hard type adhesive of Comparative Example 1, since the shrinkage and expansion of the polarizing plate is suppressed, the light leakage is excellent, but the initial adhesive force is low, and the shrinkage force of the film cannot be tolerated, thus showing a disadvantage in durability. It can also be seen that there is no antistatic performance.

When the pyridinium salt antistatic agent of Comparative Example 2 was applied, transparency was reduced due to incompatibility with the pressure-sensitive adhesive when excessively added, and the phenomenon of failing to maintain the existing light leakage was affected by affecting the cohesive properties of the pressure-sensitive adhesive.

The lithium salt antistatic agent of Comparative Example 3 did not affect the cohesive force, but the antistatic performance was lower than that of the examples, and it did not exhibit functionality in terms of initial adhesion improvement and durability.

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (13)

The pressure-sensitive adhesive, characterized in that the surface resistance is 10 ⁸ to 10 ¹² Ω / sq, and the luminance difference ΔL between the edge portion and the center portion by the following formula is more than 0 and less than 1.
ΔL = [(a + b + d + e) / 4] -c
(A, b, d, e in the above is the average of the luminance of the position corresponding to the area of 1/16 of the total area from the edge of each side of the optical member, c is the average luminance of the area 1/32 of the center of the optical member) .

Pressure-sensitive adhesive comprising an alkylammonium compound represented by the formula (1):
[Formula 1]

(Wherein n is an integer from 0 to 15).
The pressure sensitive adhesive of claim 1 or 2, wherein the pressure sensitive adhesive has an initial adhesive strength of 100 to 250 gf measured by a texture analyzer after the ball probe is adhered to the adhesive surface for 2 seconds.
The pressure-sensitive adhesive according to any one of claims 1 to 3, wherein the pressure-sensitive adhesive has a creep distance of 1 to 50 µm measured by a tension analyzer after attachment to a glass plate and left for 3 days. .
The pressure sensitive adhesive according to any one of claims 1 to 3, wherein the pressure sensitive adhesive has a haze of 0 to 0.1%.
The pressure sensitive adhesive according to claim 1 or 2, wherein the pressure sensitive adhesive comprises a (meth) acrylate copolymer, a crosslinking agent, and an alkylammonium compound of Formula 1 below:
[Formula 1]

(Wherein n is an integer from 0 to 15).
The pressure sensitive adhesive according to claim 6, wherein the pressure sensitive adhesive comprises 100 parts by weight of the (meth) acrylate copolymer, 0.01 to 10 parts by weight of a crosslinking agent and 0.01 to 10 parts by weight of an alkylammonium compound.
The pressure-sensitive adhesive according to claim 6, wherein the (meth) acrylate copolymer has a carboxyl group and a hydroxyl group.
The pressure-sensitive adhesive according to claim 8, wherein the (meth) acrylate-based copolymer is a copolymer of an alkyl (meth) acrylate of C1-16, a monomer having a carboxyl group, and a monomer having a hydroxy group.
The pressure-sensitive adhesive of claim 6, wherein the (meth) acrylate copolymer has a weight average molecular weight of 1,000,000 to 1,500,000 g / mol.
The pressure-sensitive adhesive according to claim 6, wherein the crosslinking agent is a combination of an isocyanate type and a carbodiimide type.
The pressure-sensitive adhesive according to claim 7, wherein the pressure-sensitive adhesive further comprises 0.01 to 3 parts by weight of a silane coupling agent.
The optical member according to claim 1 or 2, wherein the pressure sensitive adhesive of any one of the optical films comprises an adhesive layer on one side or both sides of the optical film.