KR20180125368A - Adhesive composition and surface-protective film - Google Patents

Abstract

The present invention is to provide an adhesive composition and a surface protective film, which has improved balance of adhesive strength between a high peeling speed and a low peeling speed, has excellent adhesion performance having fouling resistance, does not deteriorated with time, and has excellent antistatic performance. The adhesive composition comprises: (A) a (meth)acrylate ester monomer having C1-C18 carbon atoms of an alkyl group; (B) a copolymerizable monomer containing a hydroxyl group; and (C) a polymer of an acryl group of a copolymer with the acid number of 0.1-1.0, that copolymerizes a copolymerizable monomer containing a carboxyl group. In addition, the adhesive composition includes 70 parts by weight or more of 2-ethylhexylacrylate for 100 parts by weight of (A) the (meth)acrylate ester monomer having C1-C18 carbon atoms of an alkyl group. Furthermore, the adhesive composition includes a cross-linking agent which is (D) an isocyanate compound with three or more functional groups, and includes an antistatic agent which is an ionic compound having an anion with F7 or more of the number of fluorine atoms and having a melting point of 25-50°C.

Description

ADHESIVE COMPOSITION AND SURFACE-PROTECTIVE FILM < RTI ID = 0.0 >

The present invention relates to a pressure-sensitive adhesive composition and a surface protective film containing an antistatic agent. More specifically, the present invention relates to a pressure-sensitive adhesive composition having excellent adhesion performance for a surface protective film used for protecting the surface of a polarizing plate by being adhered to a polarizing plate constituting a liquid crystal display, Film.

BACKGROUND ART Conventionally, in the process of manufacturing an optical member such as a polarizing plate, which is a member constituting a liquid crystal display, a surface protective film for temporarily protecting the surface of an optical member is adhered. Such a surface protective film is used only for the process of manufacturing the optical member, and is peeled off from the optical member at the time of mounting the optical member on the liquid crystal display. Since the surface protective film for protecting the surface of such an optical member is used only in the manufacturing process, it is sometimes called a process film in general.

As described above, the surface protective film used in the step of producing the optical member has a pressure-sensitive adhesive layer formed on one side of a polyethylene terephthalate (PET) resin film having optical transparency. A releasable release film for protecting the pressure-sensitive adhesive layer is bonded onto the pressure-sensitive adhesive layer until the pressure-sensitive adhesive layer is bonded to the optical member.

The optical member such as a polarizing plate is subjected to product inspection accompanied by optical evaluation such as display ability, color, contrast, foreign substance incorporation, etc. of the liquid crystal display panel in a state where the surface protective film is stuck. For this reason, the performance required for the surface protective film is required to have no adhesion of bubbles or foreign matter and a low molecular weight component of the pressure-sensitive adhesive composition to the pressure-sensitive adhesive layer, that is, to have stain resistance.

Further, when peeling the surface protective film from an optical member such as a polarizing plate, peeling electrification caused by static electricity generated when the pressure sensitive adhesive layer is peeled off from the adherend may affect the failure of the electric control circuit of the liquid crystal display . For this reason, it is required that the pressure-sensitive adhesive layer has excellent antistatic performance.

In recent years, an acrylic resin such as polymethylmethacrylate (PMMA) or the like such as polyethylene terephthalate (PET) or the like can be used as the polarizer protective layer (also referred to as a protective film) of the polarizing plate in addition to the conventional triacetylcellulose The use of a material which tends to cause peeling electrification when peeling a surface protective film of a polarizing plate such as a polyester resin, a cyclic olefin polymer or a polycarbonate has been expanded. For this reason, it is required that the antistatic property required of the pressure-sensitive adhesive layer for a surface protective film of a polarizing plate is superior to the conventional one.

In addition, when the surface protective film is finally peeled off from an optical member such as a polarizing plate, it is required to be able to peel quickly. It is required that the adhesive force is small even by the peeling speed so that it can be quickly peeled even by the so-called high-speed peeling.

As described above, in recent years, the required performance of the pressure-sensitive adhesive layer constituting the surface protective film is as follows: (1) a balance of adhesive force at a low speed separation speed and a high speed separation speed; (2) Excellent antistatic properties and the like are required in terms of ease of use in using the surface protective film.

However, each of the requirements (1) to (3) required for the pressure-sensitive adhesive layer constituting the surface-protective film can satisfy the respective required performance. However, (3) at the same time.

In order to solve these problems, for example, (1) a balance of adhesive force at a low speed peeling speed and a high speed peeling speed, (2) stain resistance, and (3) Are known.

(1) Balancing the adhesive force at a low rate of peeling and a high rate of peeling is performed by using a copolymer of a (meth) acrylic acid alkyl ester having an alkyl group having 7 or less carbon atoms and a carboxyl group-containing copolymerizable compound as a main component, , There is a problem in that the pressure-sensitive adhesive is adhered to the adherend when the pressure-sensitive adhesive is adhered for a long period of time, and the adhesiveness to the adherend increases with time. In order to avoid this, it has been known to use a copolymer of a (meth) acrylic acid alkyl ester having an alkyl group having 8 to 10 carbon atoms and a copolymerizable compound having an alcoholic hydroxyl group, and to form a pressure-sensitive adhesive layer crosslinked with a crosslinking agent Patent Document 1).

It has also been proposed that a small amount of a copolymer of a (meth) acrylic acid alkyl ester and a carboxyl group-containing copolymerizable compound is added to the same copolymer as described above, and a pressure-sensitive adhesive layer is formed by crosslinking the copolymer with a crosslinking agent. However, when they are used for surface protection of a plastic plate or the like having a low surface tension due to a low surface tension, there arises a problem of peeling phenomenon such as lifting due to heating during processing or storage, There was also a problem of poor sex.

In order to solve these problems, it is preferable that (a) 100 parts by weight of (a) a (meth) acrylic acid alkyl ester having a (meth) acrylic acid alkyl ester having an alkyl group having 8 to 10 carbon atoms as a main component, And c) 3 to 100 parts by weight of a vinyl ester of an aliphatic carboxylic acid having 1 to 5 carbon atoms is added to a copolymer of a monomer mixture containing a crosslinking agent in an equivalent amount or more with respect to the carboxyl group of the component b) (Patent Document 2).

In the pressure-sensitive adhesive composition described in Patent Document 2, peeling phenomenon such as peeling is not generated during processing or storage, and the peeling property of the adhesive force is small with time, It can be re-peeled off with a small force even when it is stored. At this time, no adhesive residue is generated on the adherend, and even when high-speed peeling is performed, re-peeling can be performed with a small force.

(2) those having stain resistance are those having a carboxyl group-containing monomer having a hydroxyl group content of less than 0.5 part by mass, a hydroxy group-containing (meth) acrylic monomer having a carboxyl group content of 0.6 to 9 parts, and a (meth) acrylic acid ester monomer having a mass ratio of 99.4 to 90.5 100 parts by mass of a (meth) acrylic copolymer having a weight average molecular weight of 100,000 or more and less than 1,000,000; And 0.1 to 5 parts by mass of a carbodiimide-based crosslinking agent (Patent Document 3).

The pressure-sensitive adhesive composition described in Patent Document 3 is characterized in that a carbodiimide-based crosslinking agent is used as a crosslinking agent of a (meth) acrylic copolymer having a specific composition. This makes it possible to provide the pressure-sensitive adhesive layer with a crosslinked structure capable of following pressure and temperature shrinkage during the autoclave treatment. Therefore, the pressure-sensitive adhesive layer formed using the pressure-sensitive adhesive composition can inhibit / prevent foaming even under high-temperature and high-pressure conditions (during the autoclave treatment), excellent in stain resistance to endophilic complexes, and excellent in transparency.

As for the excellent antistatic performance, (3) a method of incorporating an antistatic agent into a base film as a method for imparting antistatic property to the surface protective film is disclosed. Examples of the antistatic agent include (a) various cationic antistatic agents having cationic groups such as quaternary ammonium salts, pyridinium salts and primary to tertiary amino groups, (b) sulfonic acid bases, sulfuric acid ester bases, phosphoric acid An anionic antistatic agent having an anionic group such as an ester base or a phosphonic acid base, (c) an amphoteric antistatic agent such as an amino acid or an amino sulfate ester, (d) an antioxidant such as an aminoalcohol, glycerin or polyethylene glycol (E) a high molecular weight antistatic agent obtained by polymerizing an antistatic agent as described above (Patent Document 4).

Further, in recent years, it has been proposed to incorporate such an antistatic agent directly in the pressure-sensitive adhesive layer, either in the base film or not in the surface of the base film.

The antistatic pressure-sensitive adhesive composition in which a salt having an anion having a fluoro group and a sulfonyl group is dispersed is characterized in that the salt having an anion having a fluoro group and a sulfonyl group is a polyether ester containing a polyether group in the main chain And is dispersed in a state dissolved in a plasticizer (Patent Document 5).

In the pressure-sensitive adhesive composition described in Patent Document 5, an ester formed from a mono- or dicarboxylic acid having a saturated or unsaturated acyclic hydrocarbon group as a plasticizer and an alcohol having a non-cyclic hydrocarbon group having 1 to 20 carbon atoms, or an unsaturated non- A plasticizer comprising an ester in which an unsaturated group in a hydrocarbon group is epoxidized is used. The mono- or dicarboxylic acid having a saturated or unsaturated acyclic hydrocarbon group has a carbon number close to the number of carbon atoms of the acrylic monomer constituting the acrylic copolymer used in the pressure-sensitive adhesive layer, so that compatibility with the antistatic pressure- It is said that the bleed-out is suppressed because it is preferably kept in the plasticizer-acrylic antistatic pressure-sensitive adhesive composition.

Japanese Patent Application Laid-Open No. 63-225677 Japanese Laid-Open Patent Publication No. 11-256111 Japanese Laid-Open Patent Publication No. 2011-122054 Japanese Laid-Open Patent Publication No. 11-070629 Japanese Laid-Open Patent Publication No. 2014-118469

As described above, in the prior art, it is required that the pressure-sensitive adhesive layer constituting the surface protective film should have a balance of adhesive force at a low speed release speed and a high speed release speed, that it has stain resistance, Has come. However, although it is possible to satisfy the respective required performance, all of the required performance required for the pressure-sensitive adhesive layer of the surface protective film can not be satisfied at the same time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and has an object to provide a pressure-sensitive adhesive composition and a pressure-sensitive adhesive composition which are excellent in balance of adhesive force at a low speed peeling speed and a high speed peeling speed, A surface protective film is provided.

In the pressure-sensitive adhesive composition having an antistatic property and the surface protective film using the same, the relationship between the antistatic property and the stain resistance against the adherend has a trade-off relationship, and it is extremely difficult to improve the stain resistance while maintaining the antistatic property It was difficult.

However, the inventors of the present invention have found that a copolymer obtained by copolymerizing a copolymerizable monomer containing a carboxyl group, a polyether-containing silicone compound and an anion having a fluorine atom number of not less than F7 (for example, a nonafluorobutanesulfonate anion) A pressure-sensitive adhesive composition containing an antistatic agent comprising an ionic compound having a melting point of 25 占 폚 or more can solve this problem.

The present invention provides a pressure-sensitive adhesive composition containing an antistatic agent and a crosslinking agent, wherein the pressure-sensitive adhesive composition comprises (A) a (meth) acrylic acid ester monomer having an alkyl group of C1- And (C) a copolymerizable monomer containing a carboxyl group, wherein the acrylic polymer is a copolymer wherein the number of carbon atoms of the alkyl group (A) is from C1 to C18 Ethylhexyl acrylate is contained in an amount of 70 parts by weight or more in 100 parts by weight of a (meth) acrylic acid ester monomer, and the glass transition temperature of the acrylic polymer is 0 DEG C or lower and the cross-linking agent is (D) 3 The antistatic agent is an isocyanate compound having at least a functional group, and the antistatic agent is composed of a cation having an anion having a number of fluorine atoms of F7 or more and an anion Wherein the pressure-sensitive adhesive composition further comprises (E) a crosslinking retarder and (F) a crosslinking catalyst other than a tin compound as a crosslinking catalyst. do.

The pressure-sensitive adhesive composition of the present invention is a pressure-sensitive adhesive composition for a surface protective film bonded to a polarizer protective layer of a polarizer, wherein the polarizer protective layer of the polarizer is one selected from the group consisting of a TAC film, a PMMA film, It is preferable that the surface treatment performed on the surface of the polarizer protective layer of the polarizing plate is one selected from the group consisting of untreated, AG treated, LR treated, AR treated, AG-LR treated and AG-AR treated.

Wherein the anions of ionic compounds _{C 6 F 5 (CF 2)} n COO -, C 6 F 5 (CF 2) n SO 3 -, C 6 F 5 (CF 2) n O -, C 6 F 5 O ( ^{_{CF 2) n SO 3 -,}} (C 6 F 5 CO) 2 n -, (C 6 F 5 CO) 3 C -, (C 6 F 5 SO 2) 2 n -, (C 6 F 5 SO 2) ^{_{3 C -, (C 6 F}} 5 OSO 2) 2 N -, (C 6 F 5 OSO 2) 3 C -, (C 6 F 5) 4 B -, CF 3 (CF 2) 3 SO 3 - consisting of As an anion, and it is preferable that the ionic compound is contained in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the acrylic polymer as an essential component.

Wherein the cation of the ionic compound is selected from the group consisting of pyridinium, imidazolium, phosphonium, sulfonium, pyrrolidinium, guanidinium, ammonium, isooronium, thiouronium, piperidinium, pyrazolium, And morpholinium. It is preferable that the ionic compound is contained in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the acryl-based polymer as an essential component.

Sensitive adhesive layer to a low refractive index layer formed by using a composition for forming a low refractive index layer containing a fluorine compound and having a surface resistivity of the pressure-sensitive adhesive layer crosslinked with the pressure sensitive adhesive composition of 1.0 x 10 ^{+ 12} ? /? Or less, A pressure of 0.04 to 0.2 N / 25 mm at a low speed peeling rate of 0.3 m / min and a high speed of 0.04 to 0.2 N / 25 mm for a polarizing plate of a pressure-sensitive adhesive layer formed by crosslinking the pressure- And the adhesive force at a peeling speed of 30 m / min is preferably 2.0 N / 25 mm or less.

(Meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate and 2-hydroxyethyl (Meth) acrylate, N-hydroxy (meth) acrylamide, N-hydroxymethyl (meth) acrylamide and N-hydroxyethyl

(B) a copolymerizable monomer containing a hydroxyl group in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the (meth) acrylic ester monomer having (A) the C1-C18 alkyl group,

(Meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, 2- (meth) acryloyloxyethylhexahydrophthalic acid, 2- (Meth) acryloyloxyethylmaleic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) acryloyloxyethylsuccinic acid, 2- Caprolactone mono (meth) acrylate, 2- (meth) acryloyloxyethyltetrahydrophthalic acid, and the like.

(C) a carboxyl group-containing copolymerizable monomer in an amount of 0.01 to 0.5 parts by weight based on 100 parts by weight of the (meth) acrylic acid ester monomer having (A) the C1-C18 alkyl group .

Wherein the crosslinking retarder (E) is a keto-enol tautomer compound and contains 0.1 to 300 parts by weight of the crosslinking retarder (E) per 100 parts by weight of the acrylic polymer, Wherein the catalyst is at least one metal chelate compound selected from the group consisting of an aluminum chelate compound, a titanium chelate compound and an iron chelate compound, and 0.001 to 0.5 parts by weight of the crosslinking catalyst (F) relative to 100 parts by weight of the acrylic polymer , And the weight ratio of (E) / (F) is preferably 80 to 1,000.

It is preferable that the pressure-sensitive adhesive composition contains a polyether-modified siloxane compound having an HLB value of 6 to 12 and a weight average molecular weight of 10000 or less in a proportion of 0.01 to 0.5 parts by weight based on 100 parts by weight of the acrylic polymer.

(Meth) acrylic acid ester monomer having an alkyl group of C1 to 18 carbon atoms and a polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer with respect to 100 parts by weight of the acryl-based polymer, And more preferably 0.1 to 5.0 parts by weight, based on 100 parts by weight of the copolymer.

Wherein the polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer has an average number of repeating alkylene oxides constituting the polyalkylene glycol chain of 3 to 14, and the polyalkylene glycol chain-containing mono (meth) (Meth) acrylate, methoxypolyalkylene glycol (meth) acrylate and ethoxypoly (meth) acrylate as the polyalkylene glycol chain containing mono (meth) acrylic acid ester monomers, Alkylene glycol (meth) acrylate in an amount of 1 to 50 parts by weight, based on 100 parts by weight of the copolymer having a weight average molecular weight of 100,000 or more and 300,000 or less desirable.

The present invention also provides an adhesive film comprising a resin film laminated on one side thereof with a pressure-sensitive adhesive layer formed by crosslinking the pressure-sensitive adhesive composition.

The present invention also provides a surface protective film using the adhesive film.

Further, the present invention provides a surface protective film for a polarizing plate using the above-mentioned pressure-sensitive adhesive film.

The present invention also provides an optical film provided with a pressure-sensitive adhesive layer in which a pressure-sensitive adhesive layer composed of the pressure-sensitive adhesive composition is laminated on at least one surface of an optical film.

Further, the present invention provides the pressure-sensitive adhesive film in which antistatic treatment and antifouling treatment are performed on one surface of the resin film opposite to the surface on which the pressure-sensitive adhesive layer is formed.

The pressure-sensitive adhesive composition according to the present invention has excellent adhesive performance and does not deteriorate with time, and has excellent peeling electrification prevention performance as compared with the conventional pressure-sensitive adhesive composition for a surface protective film.

Particularly, the surface protective film according to the present invention is a surface protective film comprising an antireflection layer containing a fluorine compound in which an adherend is laminated on the surface of an optical film, or a low refractive index layer formed by using a composition for forming a low refractive index layer containing a fluorine compound It has excellent adhesion performance and does not deteriorate with time as compared with the surface protective film according to the prior art, and has excellent peeling electrification preventing performance. That is, the surface protective film according to the present invention has a remarkable effect in achieving both antistatic performance and stain resistance.

That is, the pressure-sensitive adhesive composition according to the present invention and the surface-protective film using the pressure-sensitive adhesive composition of the present invention have excellent adhesive performance and does not deteriorate with time, and has excellent peeling electrification preventing performance.

Hereinafter, the present invention will be described based on preferred embodiments.

The pressure-sensitive adhesive composition of the present embodiment is a pressure-sensitive adhesive composition containing an antistatic agent and a crosslinking agent, wherein the pressure-sensitive adhesive composition comprises (A) a (meth) acrylic acid ester monomer having an alkyl group of C1- (A) a (meth) acrylic polymer having an acid value of 0.1 to 1.0 in which an alkyl group having a carbon number of C1 to C18 is copolymerized with a copolymerizable monomer containing a carboxyl group and (C) Ethylhexyl acrylate in a proportion of not less than 70 parts by weight, and wherein the acrylic polymer has a glass transition temperature of 0 占 폚 or less and the crosslinking agent is (D) an isocyanate having three or more functional groups Wherein the antistatic agent is a compound having an anion having a number of fluorine atoms of F7 or higher and a melting point Wherein the pressure-sensitive adhesive composition further comprises (E) a crosslinking retarder and (F) a crosslinking catalyst other than a tin compound as a crosslinking catalyst.

The acrylic polymer used in the pressure-sensitive adhesive composition of the present embodiment is a subject polymer of the pressure-sensitive adhesive composition and has a glass transition temperature of 0 占 폚 or less. The acrylic polymer is preferably a copolymer having (A) a (meth) acrylic acid ester monomer having an alkyl group having from 1 to 18 carbon atoms as a main component.

Examples of the (meth) acrylate monomer having an alkyl group of C1-C18 in the alkyl group include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) (Meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (Meth) acrylate, decyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (Meth) acrylate, octadecyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, ) Acrylate It can be given. The alkyl group of the alkyl (meth) acrylate monomer may be any of linear, branched and cyclic.

The acrylic polymer used in the pressure-sensitive adhesive composition of the present embodiment contains (A) 2-ethylhexyl acrylate in a proportion of 70 parts by weight or more in 100 parts by weight of (meth) acrylic acid ester monomer having C1- .

The acrylic polymer used in the pressure-sensitive adhesive composition of this embodiment contains (B) a copolymerizable monomer containing a hydroxyl group. Examples of the copolymerizable monomer containing a hydroxyl group (B) include a copolymerizable monomer having a hydroxyl group such as 8-hydroxyoctyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 4-hydroxybutyl (meth) At least one compound selected from the group consisting of ethyl (meth) acrylate, N-hydroxy (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N-hydroxyethyl desirable.

(B) a copolymerizable monomer containing a hydroxyl group in an amount of 0.1 to 10 parts by weight, based on 100 parts by weight of the (meth) acrylic ester monomer having (C) To 8.5 parts by weight, and particularly preferably 2.1 to 7.5 parts by weight.

The acrylic polymer used in the pressure-sensitive adhesive composition of the present embodiment contains (C) a copolymerizable monomer containing a carboxyl group. Examples of the copolymerizable monomer containing a carboxyl group include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, 2- (meth) acryloyloxyethylhexahydrophthalic acid, 2- (Meth) acryloyloxyethylmaleic acid, 2- (meth) acryloyloxyethylmaleic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- At least one member selected from the group consisting of polycaprolactone mono (meth) acrylate, 2- (meth) acryloyloxyethyltetrahydrophthalic acid, and the like.

(C) a carboxyl group-containing copolymerizable monomer in an amount of 0.01 to 0.5 parts by weight, and preferably 0.01 to 0.5 parts by weight, relative to 100 parts by weight of the (meth) acrylic acid ester monomer in which the alkyl group (C) To 0.45 parts by weight, and particularly preferably 0.01 to 0.4 parts by weight.

The method for producing the acrylic polymer to be contained in the pressure-sensitive adhesive composition according to the present embodiment is not particularly limited, and a well-known polymerization method such as a solution polymerization method or an emulsion polymerization method can be used. The weight average molecular weight of the copolymer of the acrylic polymer may be, for example, only 50 to 300. The acid value of the acrylic polymer is preferably 0.1 to 1.0. As a result, the stain resistance can be improved. Here, "acid value" is one of the indicators indicating the content of acid, and is represented by the number of mg of potassium hydroxide required for neutralizing 1 g of a carboxyl group-containing polymer.

The pressure-sensitive adhesive composition according to the present embodiment contains (G) an antistatic agent. The antistatic agent (G) of the present embodiment is an ionic compound comprising a cation and an anion having an anion having the number of fluorine atoms of F7 or more. The ionic compound preferably has a melting point of 25 to 50 캜 and is a solid at normal temperature (for example, 25 캜). It is preferable that the ionic compound is contained in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the acryl-based polymer as an essential component.

When it is necessary to increase the antistatic performance of the pressure-sensitive adhesive layer to reduce the lower limit value of the surface resistivity to 1.0 x 10 ⁺ 10? /? Or less, the ionic compound is added in an amount of 0.01 to 15 By weight based on the total weight of the composition.

As the anion of the ionic _{compound, C 6 F 5 (CF 2} ) n COO -, C 6 F 5 (CF 2) n SO 3 -, C 6 F 5 (CF 2) n O -, C 6 F 5 _{O (CF 2) n SO 3} -, (C 6 F 5 CO) 2 N -, (C 6 F 5 CO) 3 C -, (C 6 F 5 SO 2) 2 N -, (C 6 F 5 SO ^{_{2) 3 C -, (C}} 6 F 5 OSO 2) 2 N -, (C 6 F 5 OSO 2) 3 C -, (C 6 F 5) 4 B -, CF 3 (CF 2) 3 SO 3 - At least one kind selected from the group consisting of Here, n is an integer of 1 or more.

Examples of the cation of the ionic compound include pyridinium, imidazolium, phosphonium, sulfonium, pyrrolidinium, guanidinium, ammonium, isooronium, thiouronium, piperidinium, pyrazolium, Lithium, and morpholinium. [0033] The term " a "

Specific examples of the antistatic agent (G) include, for example, methyltrioctylammonium tris (pentafluorobenzenesulfonyl) methide salt, 3-methyl-1-octylpyridinium nonafluorobutanesulfonate salt, -Ethyl-3-methylimidazolium tetrakis (pentafluorophenyl) borate salt, and 1-butyl-1-methylpiperidinium bis (pentafluorobenzenesulfonyl) imide salt.

The pressure-sensitive adhesive composition according to this embodiment further contains (D) an isocyanate compound having three or more functional groups as a crosslinking agent. Examples of the isocyanate compound having three or more functional groups (D) include biuret-modified products of diisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate and xylylene diisocyanate, And adducts with a tri- or higher-valent polyol such as trimethylolpropane or glycerin, and the like. The proportion of the (D) trifunctional or higher isocyanate compound may be, for example, from 0.01 to 5 parts by weight based on 100 parts by weight of the acrylic polymer.

The pressure-sensitive adhesive composition according to the present embodiment may contain (E) a crosslinking retarder. Examples of the crosslinking retarder (E) include a β-keto ester such as methyl acetoate, ethyl acetoate, octyl acetoate, oleyl acetoacetate, lauryl acetoacetate and stearyl acetoate, Dione, and benzoyl acetone. These are ketone-enol triorganosiloxane compounds. In the pressure-sensitive adhesive composition containing a polyisocyanate compound as a crosslinking agent, blocking of the isocyanate group of the crosslinking agent prevents excessive viscosity increase or gelation of the pressure-sensitive adhesive composition after blending of the crosslinking agent, Port life can be extended. The crosslinking retarder (E) is preferably a ketone-enol tautomer compound, and is preferably at least one selected from the group consisting of acetylacetone and ethyl acetoacetate. (E) a crosslinking retarder in an amount of 0.1 to 300 parts by weight based on 100 parts by weight of the acryl-based polymer.

The pressure-sensitive adhesive composition according to the present embodiment may contain a crosslinking catalyst other than a tin compound as the (F) crosslinking catalyst. (F) The crosslinking catalyst may be a substance that functions as a catalyst for the reaction (crosslinking reaction) between the copolymer and the crosslinking agent when the polyisocyanate compound is used as the crosslinking agent. As the crosslinking catalyst other than the tin compound, an amine compound such as a tertiary amine, an organic metal compound such as a metal chelate compound, an organic lead compound, an organic zinc compound and the like can be given.

(F) As the metal chelate compound of the crosslinking catalyst, there is a compound in which at least one Brillouin ligand L is bonded to the central metal atom M. The metal chelate compound may or may not have at least one monocyclic ligand X bonded to the metal atom M. Specific examples of the metal chelate compound include tris (2,4-pentanedionate) iron (III), iron trisacetylacetonate, titanium trisacetylacetonate, ruthenium trisacetylacetonate, zinc bisacetylacetonate, aluminum tris (2,4-hexanedionate) iron (III), bis (2,4-hexanedionate) zinc, tris (2,4-hexanedionate) titanium, Tris (2,4-hexanedionate) aluminum, tetrakis (2,4-hexanedionate) zirconium, and the like.

(F) The crosslinking catalyst is preferably at least one metal chelate compound selected from the group consisting of an aluminum chelate compound, a titanium chelate compound and an iron chelate compound. (F) a crosslinking catalyst in an amount of 0.001 to 0.5 parts by weight based on 100 parts by weight of the acryl-based polymer.

It is preferable to appropriately set the ratio of the crosslinking retarder (E) to the crosslinking catalyst (E) in that the crosslinking retarder (E) has an effect of inhibiting crosslinking in contrast to the (F) crosslinking catalyst. In order to prolong the pot life of the pressure-sensitive adhesive composition and improve the storage stability, it is preferable that the weight ratio of (E) / (F) is 80 to 1000. Here, the weight ratio of (E) / (F) is a value obtained by dividing the weight of (E) by the weight of (F).

The pressure-sensitive adhesive composition according to the present embodiment may contain (H) a polyether-modified siloxane compound as an optional component. (H) a polyether-modified siloxane compound is a siloxane compound having a polyether, a typical siloxane unit [-SiR ¹ ₂ -O-] In addition, the siloxane units having polyether ^{[-SiR 1 (R 2 O (R} 3 O ) _n R ⁴⁾ has a -O-]. (Wherein R ¹ represents one or two or more kinds of alkyl groups or aryl groups, R ² and R ³ represent one or two or more kinds of alkylene groups, and R ⁴ represents one or two or more kinds of alkyl groups or acyl groups . Examples of the polyether group include polyoxyalkylene groups such as a polyoxyethylene group [(C ₂ H ₄ O) _n ] and a polyoxypropylene group [(C ₃ H ₆ O) _n ]. In the siloxane unit having a polyether group, the terminal of the polyether group may be an OH group (R ⁴ = H in the above formula).

(H) The polyether-modified siloxane compound is preferably a polyether-modified siloxane compound having an HLB value of 6 to 12. The amount of the polyether-modified siloxane compound (H) is preferably 0.01 to 0.5 parts by weight, more preferably 0.02 to 0.35 parts by weight, and most preferably 0.02 to 0.25 parts by weight per 100 parts by weight of the acrylic polymer Is particularly preferable. The HLB value is a hydrophilic lipophilic balance (hydrophilic lipophilic ratio) defined by, for example, JIS K3211 (surfactant term).

The polyether-modified siloxane compound can be obtained, for example, by grafting an organic compound having an unsaturated bond and a polyoxyalkylene group to a polyorganosiloxane main chain having a hydrogenated silicon group by a hydrosilylation reaction. Specific examples thereof include dimethylsiloxane · methyl (polyoxyethylene) siloxane copolymer, dimethylsiloxane · methyl (polyoxyethylene) siloxane · methyl (polyoxypropylene) siloxane copolymer, dimethylsiloxane · methyl (polyoxypropylene) .

(H) The polyether-modified siloxane compound is compounded in the pressure-sensitive adhesive composition, whereby the pressure-sensitive adhesive layer and the pressure-sensitive adhesive layer can be improved. The weight average molecular weight of the (H) polyether-modified siloxane compound is preferably 10,000 or less. From the viewpoint of compatibility with the acryl-based polymer, the HLB value is low and the molecular weight is low. The polyether-modified siloxane compound having a low molecular weight is relatively high in HLB value and slightly miscible with the polymer, .

The pressure-sensitive adhesive composition according to the present embodiment may contain, as optional components, a (meth) acrylic acid ester monomer having an alkyl group of C1 to 18 carbon atoms and a mono (meth) acrylic acid ester monomer containing a polyalkylene glycol chain (Hereinafter referred to as " copolymer B ") may be contained as an antistatic auxiliary agent. The copolymer B is contained preferably in a proportion of 0.1 to 5.0 parts by weight, more preferably 0.1 to 3.5 parts by weight, and more preferably 0.1 to 2.5 parts by weight, based on 100 parts by weight of the acrylic polymer Is particularly preferable.

As the polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer (I), any of the plurality of hydroxyl groups of the polyalkylene glycol may be a compound in which one hydroxyl group is esterified as a (meth) acrylic acid ester. (Meth) acrylic acid ester group becomes a polymerizable group, it can be copolymerized with the acrylic polymer. A polyalkylene glycol mono (meth) acrylate in which the other hydroxyl group is OH, or an alkoxypolyalkylene glycol mono (meth) acrylate in which another hydroxyl group is converted into an alkyl ether.

The polyalkylene glycol constituting the polyalkylene glycol chain may be any glycol compound having one or more alkylene groups, and examples thereof include polyethylene glycol, polypropylene glycol, polybutylene glycol, polyethylene glycol-poly Polyethylene glycol-polybutylene glycol, polypropylene glycol-polybutylene glycol, polyethylene glycol-polypropylene glycol-polybutylene glycol, and the like.

It is preferable that the average number of repeats of the alkylene oxide constituting the polyalkylene glycol chain of the (I) polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer is 3 to 14. The "average number of repeating alkylene oxides" refers to the number of repeating units in the "polyalkylene glycol chain" included in the molecular structure of (I) the polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer It is the number of repeated averages. It is also preferable that the diester content in the mono (meth) acrylic acid ester monomer (I) containing polyalkylene glycol chain is 0.2% or less. Means a content (% by weight) of the polyalkylene glycol di (meth) acrylic acid ester contained in the (I) mono (meth) acrylic acid ester monomer containing a polyalkylene glycol chain.

Examples of the polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer (I) include polyalkylene glycol mono (meth) acrylate, methoxypolyalkylene glycol (meth) acrylate, ethoxypolyalkylene glycol ) Acrylate is preferable. The proportion of (I) the polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer in the copolymer B is preferably from 1 to 50 parts by weight, more preferably from 2 to 35 parts by weight By weight, more preferably 2 to 25 parts by weight.

Examples of the monomers other than the polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer copolymerized with the copolymer B include (meth) acrylic acid ester monomers having an alkyl group of C1 to 18 carbon atoms and copolymerizable monomers containing a hydroxyl group And the like. Specific examples of these monomers include (meth) acrylic monomers exemplified in (A) and (B), respectively. The monomer copolymerized with the copolymer B may be different from the monomer copolymerized with the acrylic polymer. Copolymer B may not be copolymerized with a copolymerizable monomer containing a carboxyl group.

The pressure-sensitive adhesive composition of the present embodiment is not limited to the above-mentioned additives but may be suitably blended with known additives such as surfactants, curing accelerators, plasticizers, fillers, curing retarders, processing aids, antioxidants and antioxidants. These may be used alone or in combination of two or more.

The pressure-sensitive adhesive composition of the present embodiment is preferable as a pressure-sensitive adhesive composition for a surface protective film to be bonded to a polarizer protective layer of a polarizing plate. Here, the polarizer protective layer of the polarizing plate may be one selected from the group consisting of a TAC-based film, a PMMA-based film, and a PET-based film. Here, TAC is triacetyl cellulose, PMMA is polymethyl methacrylate, and PET is an abbreviation of polyethylene terephthalate.

The surface treatment performed on the surface of the polarizer protective layer of the polarizing plate may be one selected from the group consisting of untreated, AG treated, LR treated, AR treated, AG-LR treated and AG-AR treated. Here, AG is Anti Glare, LR is Low Reflection, and AR is Anti Reflection.

A pressure-sensitive adhesive layer crosslinked pressure-sensitive adhesive composition of the present embodiment more preferably is preferable that the surface resistivity of the pressure-sensitive adhesive layer 1.0 × 10 ^{+ 12} Ω / □ or less, ^{and, 5.0 × 10 + 11 Ω /} □ or less, 1.0 × 10 ^{+ 11} Ω / □ or less. If the surface resistivity is high, the ability to escape the static electricity generated when the pressure-sensitive adhesive layer is peeled off from the adherend is deteriorated. Therefore, by sufficiently reducing the surface resistivity, the peeling electrification voltage caused by the static electricity generated when the pressure-sensitive adhesive layer is peeled off from the adherend can be reduced, and the influence on the adherend can be suppressed.

The pressure-sensitive adhesive layer to which the pressure-sensitive adhesive composition of the present embodiment is crosslinked is a pressure-sensitive adhesive layer in which the pressure-sensitive adhesive layer has a peeling electrification voltage in the range of -0.3 to +0.0 kV It is preferable that it is mine. Examples of the fluorine compound used in the composition for forming the low refractive index layer include a fluorine-containing copolymer which is one or more polymers such as fluorinated olefins, fluorinated vinyl ethers and fluorinated alkyl (meth) acrylates, fluorinated alkyl group- Compounds and the like. The fluorine-containing copolymer may be copolymerized with fluorinated monomers as well as with non-fluorinated monomers such as olefins, vinyl ethers, and (meth) acrylates. The low refractive index layer may be combined with the high refractive index layer to constitute the antireflection layer.

The adhesive force to the polarizing plate of the pressure-sensitive adhesive layer formed by crosslinking the pressure-sensitive adhesive composition of the present embodiment was 0.04 to 0.2 N / 25 mm at a low speed peeling rate of 0.3 m / min and 2.0 N / More preferably 25 mm or less, and more preferably 0.2 to 1.6 N / 25 mm at a high speed peeling speed of 30 m / min. As a result, it is possible to obtain a performance in which the adhesive force is little changed even by the peeling speed, and it is possible to peel quickly even by high-speed peeling. Further, even when peeling the surface protective film once for re-adhesion, it is easy to peel off the adherend without requiring an excessive force.

The gel fraction of the pressure-sensitive adhesive layer formed by crosslinking the pressure-sensitive adhesive composition of the present embodiment is preferably 95 to 100%, more preferably 97 to 100%. As described above, the high gel fraction makes it possible to reduce the elongation of the uncoated monomer or oligomer from the copolymer without excessive adhesive force at a low rate of peeling and to improve the durability in reworkability and high temperature and high humidity, Can be suppressed.

The pressure-sensitive adhesive film of the present embodiment is formed by forming a pressure-sensitive adhesive layer formed by crosslinking the pressure-sensitive adhesive composition of the present embodiment on one side or both sides of a resin film. The surface protective film of the present embodiment is a surface protective film comprising a pressure sensitive adhesive layer formed by crosslinking the pressure sensitive adhesive composition of the present embodiment on one side of a resin film. The pressure-sensitive adhesive composition of the present embodiment has an excellent antistatic property and is excellent in balance of adhesive force at a low speed peeling speed and a high speed peeling speed, and also has stain resistance. Therefore, it can be preferably used as a surface protective film of a polarizing plate.

As the base film of the pressure-sensitive adhesive layer and the release film (separator) for protecting the pressure-sensitive adhesive surface, a resin film such as a polyester film or the like can be used.

The antistatic treatment and the antifouling treatment may be performed on the surface of one side of the resin film opposite to the side where the pressure-sensitive adhesive layer is formed. Examples of the antistatic treatment include application or incorporation of an antistatic agent. Examples of the antifouling treatment include treatment with silicone, fluorine-containing mold release agents, coats, and silica fine particles. The releasing film may be subjected to releasing treatment by a silicone-based, fluorine-based, long-chain alkyl-based releasing agent or the like on the side of the side of the pressure-

An optical film on which a pressure-sensitive adhesive layer is formed can be obtained by laminating a pressure-sensitive adhesive layer obtained by crosslinking the pressure-sensitive adhesive composition of the present embodiment on at least one surface of the optical film. Examples of the optical film include a polarizing film, a retardation film, an antireflection film, an anti-glare film, an ultraviolet absorbing film, an infrared absorbing film, an optical compensation film, and a luminance improving film. Examples of the device to which the optical member is applied include a liquid crystal panel, an organic EL panel, and a touch panel.

In the case of optical surface protective films such as surface protective films for polarizing plates and adhesive films, it is preferable that the base film and the pressure-sensitive adhesive layer have sufficient transparency.

Example

Hereinafter, the present invention will be described in detail with reference to Examples.

≪ Preparation of acrylic polymer solution >

[Example 1]

Nitrogen gas was introduced into a reactor equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen introduction tube to replace the air in the apparatus with nitrogen gas. Then, a solvent (ethyl acetate) was added to the reaction apparatus together with 90 parts by weight of 2-ethylhexyl acrylate, 10 parts by weight of methyl acrylate, 5.5 parts by weight of 8-hydroxyoctyl acrylate, and 0.2 parts by weight of acrylic acid. Thereafter, 0.1 part by weight of azobisisobutyronitrile as a polymerization initiator was added dropwise over 2 hours, and the mixture was reacted at 65 DEG C for 6 hours to obtain an acrylic polymer solution used in Example 1. [

[Examples 2 to 6 and Comparative Examples 1 to 3]

Used in Examples 2 to 6 and Comparative Examples 1 to 3 in the same manner as in the acrylic polymer solution used in Example 1 except that the composition of the monomers was the same as that in Table 1 (A) to (C) To obtain an acrylic polymer solution.

≪ Preparation of pressure-sensitive adhesive composition and surface protective film &

[Example 1]

2.0 parts by weight of a crosslinking agent (Coronate HX), 9 parts by weight of a crosslinking retarder (acetylacetone), 0.1 part by weight of a crosslinking catalyst (titanium trisacetylacetonate) , 0.9 part by weight of a polyether-modified siloxane compound (HLB = 7), and 0.2 part by weight of a copolymer B-1 (molecular weight: 150,000) as an antioxidant (methyltrioctylammonium tris (pentafluorobenzenesulfonyl) methide salt) And the mixture was stirred and mixed to obtain the pressure-sensitive adhesive composition of Example 1. This pressure-sensitive adhesive composition was coated on a release film (PET film coated with a silicone resin) and dried at 90 占 폚 to remove the solvent to obtain a pressure-sensitive adhesive layer having a thickness of 20 占 퐉. Thereafter, a pressure-sensitive adhesive layer, on which a release film was formed on the surface opposite to the antistatic and antifouling treated surface of the substrate film (PET film having antistatic and antifouling treatment on one side), was transferred to form a base film / pressure- / Release film " of Example 1 was obtained.

[Examples 2 to 6 and Comparative Examples 1 to 3]

The surfaces of Examples 2 to 6 and Comparative Examples 1 to 3 were prepared in the same manner as in the surface protective film of Example 1 except that the additives were the same as the base materials of Copolymer B and (D) to (H) A protective film was obtained.

In Table 1, parts by weight of each component were determined as 100 parts by weight of the total of (A) the (meth) acrylic acid ester monomer having C1-C18 alkyl groups.

In Table 1, in each column of (D), (E), (F), (G), (H) and (copolymer B), 100 parts by weight of an acryl- ) Are expressed in numerical values in parentheses ().

Tables 2 to 3 show the chemical names of the weak symbols of the respective components used in Table 1. Table 2 also includes the compound names of monomers other than mono (meth) acrylic acid ester monomers containing (I) polyalkylene glycol chain among the component monomers of copolymer B shown in Table 3. On the other hand, Coronate (registered trademark) HX, HL and L are trade names of Tohso Co., Ltd., and Takenate (trade mark) D-140N is trade name of Mitsui Chemicals,

In the antistatic agent (G), G-1 to G-4 are all ionic compounds having an anion having the number of fluorine atoms of F7 or more and a solid at a melting point of 25 占 폚 or more. G-5 is an ionic compound having an anion having a fluorine atom number of F5 and a solid at a melting point of 25 DEG C or higher.

Among (H) polyether-modified siloxane compounds, H-1 to H-6 all have a weight average molecular weight of 10,000 or less.

(I) In the polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomers, the diesters in the monomers are represented by I-1 to I-3 in an amount of not more than 0.2%, and the I-4 is in a proportion of 0.8% in the monomers. In the column of group (I) of Table 3, n is a numerical value representing the average number of repeats of the alkylene oxide.

<Test Method and Evaluation>

The surface protective films of Examples 1 to 6 and Comparative Examples 1 to 3 were each aged for 7 days under an atmosphere of 23 ° C and 50% RH, and then evaluated by the following test methods.

<Test Method of Adhesive Force>

The release film was peeled off and a surface protective film on which the pressure-sensitive adhesive layer was exposed was adhered to the surface of the polarizing plate via the pressure-sensitive adhesive layer. The film was allowed to stand for one day, autoclaved at 50 DEG C and 5 atm for 20 minutes, The sample which was allowed to stand for a time was used as a measurement sample of the adhesive force. The obtained measurement sample was peeled off at a low speed (0.3 m / min) or a high speed (30 m / min) using a tensile tester in the direction of 180 °.

Here, the polarizer protective layer of the polarizing plate is one selected from the group consisting of triacetyl cellulose (TAC), polymethyl methacrylate (PMMA), and polyethylene terephthalate (PET).

Further, in the LR polarizer and the AG-LR polarizer, the surface of the polarizer protective layer of the polarizing plate contains a fluorine compound and is subjected to a low-reflection surface treatment.

<Test Method of Surface Resistivity>

After the surface protective film was aged, the release film was peeled off before bonding to the polarizing plate to expose the pressure-sensitive adhesive layer, and the surface resistivity of the pressure-sensitive adhesive layer was measured using a resistivity meter HILESTA UP-HT450 (manufactured by Mitsubishi Chemical Engineering Co., Ltd.) Respectively.

<Test Method of Peeling Voltage>

A releasing film was peeled off to form a pressure-sensitive adhesive layer, and a surface protective film was bonded to a polarizing plate having a low refractive index layer formed by using a composition for forming a low refractive index layer containing a fluorine compound on the adherend surface. When the surface protective film was peeled 180 ° at a tensile speed of 30 m / min, the voltage (voltage) generated by charging the adherend was measured using a high-precision static electricity sensor SK-035, SK-200 (manufactured by KYOSEN CO., LTD.) , And the maximum value of the measured value was set as the peeling electrification voltage.

&Lt; Test method of stain resistance &gt;

The polarizing plate subjected to the low-reflection (LR) surface treatment on one side of the glass plate was bonded with a pressure-sensitive adhesive layer (double-sided pressure-sensitive adhesive tape) using a coater. Thereafter, the surface protective film was applied to the surface of the polarizing plate using a coater. After storage for 3 days and 30 days in an environment of 23 占 폚 and 50% RH, the surface protective film was peeled off and the state of contamination on the surface of the polarizing plate was visually observed. The criterion for stain resistance was evaluated as &quot;? &Quot;, &quot;? &Quot;, &quot;? &Quot;, and &quot; x &quot;, respectively.

Table 4 shows the evaluation results of the surface protective films of Examples 1 to 6 and Comparative Examples 1 to 3. The &quot; surface resistivity &quot; is represented by a method (m is an arbitrary real number value and n is a positive integer) in which "m x 10 ^{+ n} " is "mE + n". The column of &quot; polarizer protective layer of polarizer &quot; shows the material and surface treatment of the polarizer protective layer of the polarizer used in the adhesion test. "Plain" means "untreated".

The surface protective films of Examples 1 to 6 had an adhesive force of 0.04 to 0.2 N / 25 mm at a low speed peeling rate of 0.3 m / min and an adhesive force of 2.0 N / 25 mm Or less, and the adhesive performance was excellent.

Further, the surface protective films of Examples 1 to 6 were prepared in such a manner that the surface resistivity of the pressure-sensitive adhesive layer was 1.0 × 10 ^{+ 12} ? /? Or less, and the low refractive index layer formed by using the composition for forming a low refractive index layer containing a fluorine compound, The peeling electrification voltage of the pressure-sensitive adhesive layer was in the range of -0.3 to +0.0 kV, and the antistatic performance was excellent.

In addition, the surface protective films of Examples 1 to 6 were free from contamination of the polarizing plate as a substrate even after storage over a period of 3 days and 30 days, and also had excellent contamination resistance.

That is, it has been demonstrated that the evaluation results shown in Table 4 for the surface protective films of Examples 1 to 6 have solved the problems of the present invention.

In the surface protective film of Comparative Example 1, in the acrylic polymer contained in the pressure-sensitive adhesive composition, the proportion of 2EHA in the 100 parts by weight of (A) the (meth) acrylic acid ester monomer having C1-18 carbon atoms in the alkyl group was 50 parts by weight , And (C) a copolymerizable monomer containing a carboxyl group is not copolymerized. Further, in the pressure-sensitive adhesive composition according to the surface protective film of Comparative Example 1, the antistatic agent contains an anion of F5 having the number of fluorine atoms of less than F7. For this reason, the surface protective film of Comparative Example 1 had a large adhesive force of the pressure-sensitive adhesive layer, high peeling electrification voltage, and poor resistance to contamination.

In addition, in the surface protective film of Comparative Example 2, the acid value of the acrylic polymer contained in the pressure-sensitive adhesive composition exceeded 1.0, and the stain resistance was poor.

In addition, the antistatic agent contained in the pressure-sensitive adhesive composition of Comparative Example 3 contained an anion of F5 having the number of fluorine atoms of less than F7, and the stain resistance was bad.

As described above, the problems of the present invention were not solved in the surface protective films of Comparative Examples 1 to 3.

Claims (15)

As a pressure-sensitive adhesive composition containing an antistatic agent and a crosslinking agent,
The pressure-
(A) a (meth) acrylic acid ester monomer having an alkyl group having from 1 to 18 carbon atoms,
(B) a copolymerizable monomer containing a hydroxyl group,
(C) an acrylic polymer of a copolymer having an acid value of 0.1 to 1.0 in which a copolymerizable monomer containing a carboxyl group is copolymerized,
Wherein the acrylic polymer comprises 2-ethylhexyl acrylate in a proportion of at least 70 parts by weight, based on 100 parts by weight of the (meth) acrylic acid ester monomer having (A) the C1-C18 alkyl group as the alkyl group,
Wherein the acrylic polymer has a glass transition temperature of 0 占 폚 or lower,
Wherein the crosslinking agent is (D) an isocyanate compound having three or more functional groups,
Wherein the antistatic agent is an ionic compound comprising a cation and an anion having an anion having a fluorine atom number of not less than F7 and a melting point of from 25 to 50 캜,
Wherein the pressure-sensitive adhesive composition further comprises (E) a crosslinking retarder and (F) a crosslinking catalyst other than a tin compound as a crosslinking catalyst. The method according to claim 1,
As a pressure-sensitive adhesive composition for a surface protective film to be bonded to a polarizer protective layer of a polarizing plate,
Wherein the polarizer protective layer of the polarizing plate is one selected from the group consisting of a TAC-based film, a PMMA-based film and a PET-based film and the surface treatment performed on the surface of the polarizer protective layer of the polarizing plate is untreated, Wherein the pressure-sensitive adhesive composition is one selected from the group consisting of AR-treatment, AR-treatment, AG-LR treatment and AG-AR treatment. 3. The method according to claim 1 or 2,
Wherein the anions of ionic compounds _{C 6 F 5 (CF 2)} n COO -, C 6 F 5 (CF 2) n SO 3 -, C 6 F 5 (CF 2) n O -, C 6 F 5 O ( ^{_{CF 2) n SO 3 -,}} (C 6 F 5 CO) 2 N -, (C 6 F 5 CO) 3 C -, (C 6 F 5 SO 2) 2 N -, (C 6 F 5 SO 2) ^{_{3 C -, (C 6 F}} 5 OSO 2) 2 N -, (C 6 F 5 OSO 2) 3 C -, (C 6 F 5) 4 B -, CF 3 (CF 2) 3 SO 3 - consisting of And at least one selected from the group consisting of anions,
Wherein the ionic compound is contained in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the acryl-based polymer as an essential component. 3. The method according to claim 1 or 2,
Wherein the cation of the ionic compound is selected from the group consisting of pyridinium, imidazolium, phosphonium, sulfonium, pyrrolidinium, guanidinium, ammonium, isooronium, thiouronium, piperidinium, pyrazolium, Morpholinium, and the like.
Wherein the ionic compound is contained in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the acryl-based polymer as an essential component. 3. The method according to claim 1 or 2,
Wherein the pressure-sensitive adhesive layer crosslinked with the pressure-sensitive adhesive composition has a surface resistivity of 1.0 10 ^{+ 12} ? /? Or less,
The peeling electrification voltage of the pressure-sensitive adhesive layer for the low-refractive index layer formed by using the composition for forming a low-refractive index layer containing a fluorine compound is within a range of -0.3 to +0.0 kV,
A pressure-sensitive adhesive force of 0.04 to 0.2 N / 25 mm at a low speed peeling speed of 0.3 m / min and a pressure of 2.0 N / 25 mm or less at a high speed peeling speed of 30 m / min &Lt; / RTI &gt; 3. The method according to claim 1 or 2,
(Meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate and 2-hydroxyethyl (Meth) acrylate, N-hydroxy (meth) acrylamide, N-hydroxymethyl (meth) acrylamide and N-hydroxyethyl
(B) a copolymerizable monomer containing a hydroxyl group in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the (meth) acrylic ester monomer having (A) the C1-C18 alkyl group,
(Meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, 2- (meth) acryloyloxyethylhexahydrophthalic acid, 2- (Meth) acryloyloxyethylmaleic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) acryloyloxyethylsuccinic acid, 2- Caprolactone mono (meth) acrylate, 2- (meth) acryloyloxyethyltetrahydrophthalic acid, and the like.
(C) a carboxyl group-containing copolymerizable monomer in an amount of 0.01 to 0.5 parts by weight based on 100 parts by weight of the (meth) acrylic acid ester monomer having (A) the C1-C18 alkyl group Lt; / RTI &gt; 3. The method according to claim 1 or 2,
Wherein said crosslinking retarder (E) is a keto enol tautomer compound,
(E) a crosslinking retarder in an amount of 0.1 to 300 parts by weight based on 100 parts by weight of the acryl-based polymer,
The crosslinking catalyst (F) is at least one metal chelate compound selected from the group consisting of an aluminum chelate compound, a titanium chelate compound and an iron chelate compound,
(F) a crosslinking catalyst in an amount of 0.001 to 0.5 parts by weight based on 100 parts by weight of the acryl-based polymer,
Wherein the weight ratio of (E) / (F) is 80 to 1000. 3. The method according to claim 1 or 2,
Wherein the pressure-sensitive adhesive composition comprises 0.01 to 0.5 parts by weight of a polyether-modified siloxane compound having an HLB value of 6 to 12 and a weight-average molecular weight of 10,000 or less based on 100 parts by weight of the acrylic polymer. 3. The method according to claim 1 or 2,
(Meth) acrylic acid ester monomer having an alkyl group of C1 to 18 carbon atoms and a polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer with respect to 100 parts by weight of the acryl-based polymer, By weight of a copolymer having a molecular weight of more than 10,000 and not more than 300,000 in a proportion of 0.1 to 5.0 parts by weight. 3. The method according to claim 1 or 2,
Wherein the polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer has an average number of repeating alkylene oxides constituting the polyalkylene glycol chain of 3 to 14,
The diester content in the mono (meth) acrylic acid ester monomer containing polyalkylene glycol chain is 0.2% or less,
As the above-mentioned polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer, polyalkylene glycol mono (meth) acrylate, methoxypolyalkylene glycol (meth) acrylate, ethoxypolyalkylene glycol , In an amount of 1 to 50 parts by weight, based on 100 parts by weight of the copolymer having a weight average molecular weight of 100,000 to 300,000. Wherein a pressure-sensitive adhesive layer formed by crosslinking the pressure-sensitive adhesive composition of claim 1 or 2 is laminated on one side of the resin film. A surface protective film using the adhesive film of claim 11. A surface protective film for a polarizing plate, wherein the pressure-sensitive adhesive film of claim 11 is used. An optical film comprising a pressure-sensitive adhesive layer formed by laminating a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition of claim 1 or 2 on at least one surface of an optical film. 12. The method of claim 11,
Wherein an antistatic treatment and an antifouling treatment are carried out on one side of the resin film opposite to the side where the pressure-sensitive adhesive layer is formed.