KR101511079B1 - Adhesive composition and surface-protective adhesive film - Google Patents

Abstract

The present invention provides a pressure-sensitive adhesive composition having excellent antistatic performance, excellent balance of adhesive force at peeling at a low speed and peeling at a high speed, and excellent durability and rework performance.
The pressure-sensitive adhesive composition of the present invention comprises (A) a (meth) acrylic acid ester monomer having an alkyl group of C4 to C10, (B) a copolymerizable monomer containing a hydroxyl group, (C) a copolymerizable monomer containing a carboxyl group (Meth) acrylic acid ester monomer having a hydroxyl group and (D) a polyalkylene glycol mono (meth) acrylic acid ester monomer, and (E) a nitrogen-containing vinyl monomer containing no hydroxyl group or an alkyl (G) a crosslinking retarder, (H) a crosslinking catalyst, (I) an antistatic agent, and (J) a polyether-modified siloxane compound, wherein the acid value of the acrylic polymer 0.01 to 8.0.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a pressure-sensitive adhesive composition,

The present invention relates to a surface protective film used in a liquid crystal display manufacturing process. More specifically, the present invention relates to a pressure-sensitive adhesive composition for a surface-protective film which adheres (adheres) to the surface of an optical member such as a polarizing plate or a retardation plate constituting a liquid crystal display to protect the surface of an optical member such as a polarizing plate or a retarder, And a surface protective film.

BACKGROUND ART Conventionally, in a step of manufacturing optical members such as a polarizing plate and a retarder, which constitute a liquid crystal display, a surface protective film is temporarily adhered to the surface of an optical member. At the time when the optical member is mounted on the liquid crystal display, the surface protective film is peeled off from the optical member. Since the surface protective film for protecting the surface of the optical member is used only in the manufacturing process, it is sometimes called a process film.

In the surface protective film used in the process of manufacturing the optical member, a pressure-sensitive adhesive layer is formed on one side of a polyethylene terephthalate (PET) resin film having optical transparency. Further, a peeled 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.

In the optical member such as a polarizing plate and a phase difference plate, a product inspection accompanied by optical evaluation such as display ability, color, contrast, foreign substance incorporation, etc. of the liquid crystal display plate is performed in a state in which the surface protective film is bonded. For this reason, the performance required for the surface protective film is that no bubbles or foreign matter adhere to the pressure-sensitive adhesive layer.

In recent years, excellent antistatic performance is required to prevent generation of static electricity when the surface protective film is peeled off from optical members such as a polarizing plate and a retarder. This is because there is a possibility that the electric control circuit of the liquid crystal display may fail when the adherend layer is peeled off due to the static electricity generated during stripping.

Further, when the surface protective film is applied to an optical member such as a polarizing plate or a retardation plate, the surface protective film may be peeled once and then the surface protective film may be attached again for various reasons. At this time, there is a demand for a surface protective film which is easily peeled off from the optical member of the adherend (having a reworkability).

In addition, when the surface protective film is peeled off from optical members such as a polarizing plate and a retarder, it is required that the surface protective film can be quickly peeled off. It is required that the influence by the peeling speed of the adhesive force is small so that it can be quickly peeled off even by the so-called peeling at the high speed.

Thus, in recent years, the following performance (1) to (4) have been required as required performance for the pressure-sensitive adhesive layer constituting the surface protective film.

(1) Balance the adhesive force in peeling at low speed and peeling at high speed.

(2) One capable of preventing the occurrence of adhesive residue.

(3) Having excellent antistatic performance.

(4) having rework performance.

However, it is very difficult to simultaneously satisfy all of the requirements (1) to (4) required for the pressure-sensitive adhesive layer of the surface protective film at the same time, although each of the above requirements (1) to (4) Do.

For example, the following proposal is known as to (1) balance the adhesive force in peeling at a low speed and peeling at a high speed, and (2) preventing the occurrence of adhesive residue.

In the acrylic pressure-sensitive adhesive comprising a copolymer of a (meth) acrylic acid alkyl ester having an alkyl group having a carbon number of 7 or less and a carboxyl group-containing copolymerizable compound as a main component and crosslinking the same with a crosslinking agent, There is a problem that the adhesive force is adhered to the side surface of the complex and the adhesive strength to the adherend increases with time. In order to prevent this problem, a pressure-sensitive adhesive (pressure-sensitive adhesive) in which a copolymer of a (meth) acrylic acid alkyl ester having an alkyl group of 8 to 10 carbon atoms and a copolymerizable compound having an alcoholic hydroxyl group is used and crosslinked with a crosslinking agent is known (Patent Document 1).

Further, there has been proposed a pressure-sensitive adhesive in which a small amount of a copolymer of a (meth) acrylic acid alkyl ester and a carboxyl group-containing copolymerizable compound is mixed with the same copolymer as described above and crosslinked with a crosslinking agent. However, when they are used for protecting the surface of a plastic plate or the like having a low surface tension due to low surface tension, there arises a problem of peeling phenomenon such as lifting due to heating at the time of processing or storage, There is a problem that re-peelability is deteriorated.

(A) 100 parts by weight of a (meth) acrylic acid alkyl ester having a (meth) acrylic acid alkyl ester having an alkyl group of 8 to 10 carbon atoms as a main component, (b) 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 relative 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 peeling phenomenon such as peeling does not occur, and the peeling property is small, It can be re-peeled off with a small force even if it is stored for a long period of time. At this time, it is possible to re-peel off with a small force even in peeling at high speed without generating adhesive residue on the adherend.

Also, (3) those having excellent antistatic properties include a method of kneading an antistatic agent on a base film as a method for imparting antistatic properties to the surface protective film, and the like. 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) a positive antistatic agent such as amino acid or amino sulfate ester, (d) a nonionic antioxidant such as amino alcohol, glycerin or polyethylene glycol (E) a polymer-type antistatic agent obtained by polymerizing an antistatic agent as described above (Patent Document 3).

Further, in recent years, it has been proposed to incorporate such an antistatic agent into a substrate film, or directly to the pressure-sensitive adhesive layer without applying the antistatic agent to the surface of the substrate film.

(4) A pressure-sensitive adhesive composition in which a curing agent of an isocyanate compound and a specific silicate oligomer are blended in an acrylic resin in an amount of 0.0001 to 10 parts by weight based on 100 parts by weight of an acrylic resin is proposed (Patent Document 4).

Patent Document 4 discloses a method for producing a polyester resin composition which comprises an acrylic acid alkyl ester having an alkyl group of about 2 to 12 carbon atoms or a methacrylic acid alkyl ester having an alkyl group of about 4 to 12 as a main monomer component, Containing functional monomer component and a functional group-containing monomer component. In general, the main monomer is preferably contained in an amount of 50% by weight or more, and the content of the functional group-containing monomer component is 0.001 to 50% by weight, preferably 0.001 to 25% by weight, more preferably 0.01 to 25% % Is preferable. The pressure-sensitive adhesive composition described in Patent Document 4 is said to have reworkability because it exhibits a small change in cohesive force and adhesive force over time under high temperature or high temperature and high humidity, and exhibits an excellent adhesive force against curved surfaces.

Generally, if the pressure-sensitive adhesive layer has a soft property, the pressure-sensitive adhesive residue tends to be generated, and the workability tends to decrease. In other words, it is difficult to peel off when it is mistakenly bonded, and it is apt to be difficult to attach again. Therefore, it is necessary to cross-link a monomer having a functional group such as a carboxyl group to a main agent so as to make the pressure-sensitive adhesive layer have a constant hardness, in order to have a workability.

Japanese Patent Application Laid-Open No. 63-225677 Japanese Laid-Open Patent Publication No. 11-256111 Japanese Laid-Open Patent Publication No. 11-070629 Japanese Unexamined Patent Publication No. 8-199130

In the prior art, there is a demand for a balance between adhesive force at peeling at a low speed and peeling at a high speed, excellent antistatic performance, rework performance, and the like as required performance for a pressure-sensitive adhesive layer constituting a surface protective film. Each of the required performance can be satisfied, but the required performance of the pressure sensitive adhesive layer of the surface protective film can not be satisfied.

The present invention has been made in view of the above circumstances. An object of the present invention is to provide a pressure-sensitive adhesive composition and a surface protective film which have excellent antistatic properties and are excellent in balance of adhesive force at peeling at a low speed and peeling at a high speed, will be.

(B) a copolymerizable monomer containing a hydroxyl group; (C) a copolymerizable monomer containing a carboxyl group; and (C) a copolymerizable monomer containing a carboxyl group, wherein the alkyl group has a carbon number of from C4 to C10, (Meth) acrylic acid ester monomer having a hydroxyl group and (E) a nitrogen-containing vinyl monomer or an alkoxy group-containing alkyl (meth) acrylate monomer having no hydroxyl group, and (D) a polyalkylene glycol mono (G) a crosslinking retarder, (H) a crosslinking catalyst, (I) an antistatic agent, and (J) a polyether-modified siloxane compound, which are composed of an acrylic polymer as a copolymer And the acid value of the acryl-based polymer is 0.01 to 8.0.

(Meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, At least one compound selected from the group consisting of ethyl (meth) acrylate, N-hydroxy (meth) acrylamide, N-hydroxymethyl (meth) acrylamide and N-hydroxyethyl Wherein 0.1 to 5.0 parts by weight of the copolymerizable monomer containing the hydroxyl group (B) is contained in 100 parts by weight of the (meth) acrylic ester monomer having (A) the alkyl group of C4 to C10, (Meth) acrylate, 4-hydroxybutyl (meth) acrylate and 8-hydroxyoctyl (meth) acrylate in the copolymerizable monomer containing hydroxyl group is 0 to 0.9 weight It is desirable to be wife.

Wherein the copolymerizable monomer containing a carboxyl group is at least one selected from the group consisting of (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- (Meth) acryloyloxyethyltetrahydrophthalic acid, wherein the (A) the (meth) acryloyloxyethyltetrahydrophthalic acid is at least one selected from the group consisting of (meth) acrylic acid, (C) a copolymerizable monomer containing a carboxyl group is contained in an amount of 0.35 to 1.0 part by weight based on 100 parts by weight of the acrylic ester monomer.

Wherein the polyalkylene glycol mono (meth) acrylate monomer (D) is at least one monomer selected from the group consisting of polyalkylene glycol mono (meth) acrylate, methoxypolyalkylene glycol (meth) acrylate, ethoxypolyalkylene glycol (Meth) acrylate monomer having a carbon number of C4 to C10 in the alkyl group (A) is preferably 1 to 20 parts by weight, based on 100 parts by weight of the (meth) acrylic acid ester monomer.

Wherein the nitrogen-containing vinyl monomer or alkoxy group-containing alkyl (meth) acrylate monomer (E) containing no hydroxyl group is used in an amount of 100 parts by weight or more based on 100 parts by weight of the (meth) acrylic acid ester monomer having an alkyl group of C4- Preferably 1 to 20 parts by weight.

Wherein the isocyanurate compound of the hexamethylene diisocyanate compound (F), the isocyanurate compound of the isophorone diisocyanate compound, the adduct of the hexamethylene diisocyanate compound, the isophorone diisocyanate compound of the hexamethylene diisocyanate compound (F) at least one selected from the group consisting of an adduct of hexamethylene diisocyanate compound, a burette of hexamethylene diisocyanate compound and a burette of isophorone diisocyanate compound, It is preferable that the isocyanate compound is contained in an amount of 0.4 to 5.0 parts by weight.

Wherein the antistatic agent (I) is an ionic compound having a melting point of 30 to 80 DEG C, which is contained in an amount of 0.1 to 5.0 parts by weight based on 100 parts by weight of the copolymer, or 0.1 to 5.0% A quaternary ammonium salt type ionic compound containing an acryloyl group is preferable.

Wherein the polyether-modified siloxane compound (J) is a polyether-modified siloxane compound having an HLB value of 7 to 12, and the polyether-modified siloxane compound (J) is contained in an amount of 0.01 to 0.5 parts by weight per 100 parts by weight of the copolymer .

It is preferable that the (G) crosslinking retarder is a keto-enol ternotropic compound and 1.0 to 5.0 parts by weight of the crosslinking retarder (G) is added to 100 parts by weight of the copolymer.

It is preferable that the (H) crosslinking catalyst is an organotin compound, and the crosslinking catalyst (H) is contained in an amount of 0.01 to 0.5 parts by weight based on 100 parts by weight of the copolymer.

It is preferable that the pressure-sensitive adhesive layer to be crosslinked with the pressure-sensitive adhesive composition has an adhesive force of 0.05 to 0.1 N / 25 mm at a low speed peeling speed of 0.3 m / min and an adhesive force of 1.0 N / 25 mm or less at a high speed peeling speed of 30 m / .

It is preferable that the pressure-sensitive adhesive layer to be crosslinked with the pressure-sensitive adhesive composition has a surface resistivity of 5.0 x 10 ⁺ 10? /? Or less and a peeling electrification voltage of 占 0 to 0.3 kV.

The present invention also provides an adhesive film in which a pressure-sensitive adhesive layer crosslinked with the pressure-sensitive adhesive composition is formed on one side or both sides of a resin film.

The present invention also provides a surface protective film comprising a pressure sensitive adhesive layer crosslinked with the pressure sensitive adhesive composition formed on one side of a resin film, wherein the surface protective film is overlaid with the pressure sensitive adhesive layer with a ballpoint pen, And the surface protective film is characterized by being free of the surface protective film.

The surface protective film can be used as a surface protective film of a polarizing plate.

It is preferable that antistatic and antifouling treatment is performed on the side of the resin film opposite to the side where the pressure-sensitive adhesive layer is formed.

According to the present invention, it is possible to satisfy all the performance required for the pressure-sensitive adhesive layer of the surface protective film, which can not be solved by the prior art. In addition, excellent antistatic performance and excellent adhesive residue remanence prevention performance can be obtained. Specifically, the amount of the antistatic agent to be added can be reduced while maintaining an excellent antistatic property, and the performance of preventing the occurrence of adhesive residue can be further improved.

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

The pressure-sensitive adhesive composition of the present invention is a pressure-sensitive adhesive composition in which the main theme is (A) a (meth) acrylic acid ester monomer having an alkyl group of C4 to C10, (B) a copolymerizable monomer containing a hydroxyl group, (Meth) acrylate monomers containing at least one nitrogen-containing vinyl monomer or alkoxy group-containing alkyl (meth) acrylate monomer having no hydroxyl group and (E) a polyalkylene glycol mono (G) a crosslinking retarder, (H) a crosslinking catalyst, (I) an antistatic agent, and (J) a polyether-modified siloxane compound, each of which is composed of a chain acryl- And the acid value of the acryl-based polymer is from 0.01 to 8.0.

(A) Examples of the (meth) acrylic acid ester monomer having an alkyl group having a carbon number of C4 to C10 include butyl (meth) acrylate, isobutyl (meth) acrylate, pentyl (meth) acrylate, hexyl (Meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl Acrylate, and the like.

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) (Meth) acrylate such as ethyl (meth) acrylate, N-hydroxy (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N-hydroxyethyl (Meth) acrylamides containing hydroxyl groups.

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

It is preferable that 0.1 to 5.0 parts by weight of the copolymerizable monomer containing the hydroxyl group (B) is contained relative to 100 parts by weight of the (meth) acrylate monomer having (A) the alkyl group of C4 to C10.

The total amount of 8-hydroxyoctyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate among the copolymerizable monomers containing a hydroxyl group (B) , And less than 1 part by weight (even if not contained) is preferable, and 0 to 0.9 parts by weight is preferable.

(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) from 0.35 to 1.0 part by weight, more preferably from 0.35 to 0.6 part by weight, of a copolymerizable monomer containing a carboxyl group (C) relative to 100 parts by weight of the (meth) acrylic acid ester monomer having (A) .

As the (D) polyalkylene glycol mono (meth) acrylic acid ester monomer, 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 subject polymer. The other hydroxyl group may be the same as OH, or may be an alkyl ether such as methyl ether or ethyl ether, or a saturated carboxylic acid ester such as acetic acid ester.

Examples of the alkylene group of the polyalkylene glycol include an ethylene group, a propylene group, and a butylene group, but are not limited thereto. The polyalkylene glycol may be a copolymer of two or more kinds of polyalkylene glycols such as polyethylene glycol, polypropylene glycol and polybutylene glycol. Examples of the copolymer of polyalkylene glycol include polyethylene glycol-polypropylene glycol, polyethylene glycol-polybutylene glycol, polypropylene glycol-polybutylene glycol, and polyethylene glycol-polypropylene glycol-polybutylene glycol. The copolymer may be a block copolymer or a random copolymer.

Examples of the polyalkylene glycol mono (meth) acrylate monomer (D) include polyalkylene glycol mono (meth) acrylate, methoxypolyalkylene glycol (meth) acrylate, ethoxypolyalkylene glycol (meth) And at least one selected from the group consisting of:

More specifically, there may be mentioned polyolefin such as polyethylene glycol-mono (meth) acrylate, polypropylene glycol-mono (meth) acrylate, polybutylene glycol- mono (meth) acrylate, polyethylene glycol-polypropylene glycol- Poly (ethylene glycol) -polybutylene glycol-mono (meth) acrylate, polypropylene glycol-polybutylene glycol-mono (meth) acrylate, polyethylene glycol-polypropylene glycol- (Meth) acrylate, methoxypolyethylene glycol- (meth) acrylate, methoxypolypropylene glycol- (meth) acrylate, methoxypolybutylene glycol- (meth) acrylate, methoxypolyethylene glycol-polypropylene glycol- ) Acrylate, methoxy-polyethylene glycol-polybutylene glycol- (meth) acrylate, methoxy-polypropylene glycol-polybutylene (Meth) acrylate, methoxypolyethylene glycol-polypropylene glycol-polybutylene glycol- (meth) acrylate, ethoxypolyethylene glycol- (meth) acrylate, ethoxypolypropylene glycol- (Meth) acrylate, ethoxypolyethylene glycol (meth) acrylate, ethoxypolyethylene glycol-methacrylate, ethoxypolyethylene glycol- (meth) acrylate, ethoxypolyethylene glycol-polypropylene glycol- (Meth) acrylate, ethoxy-polyethylene glycol-polypropylene glycol-polybutylene glycol- (meth) acrylate, and the like.

(Meth) acrylate monomer (D) is preferably contained in an amount of 1 to 20 parts by weight based on 100 parts by weight of the (meth) acrylic ester monomer having (A) the alkyl group having C4 to C10 carbon atoms.

(E), examples of the nitrogen-containing vinyl monomer include an amide bond-containing vinyl monomer, an amino group-containing vinyl monomer, and a nitrogen-containing heterocyclic structure-containing vinyl monomer. More specifically, there may be mentioned N-vinyl-2-pyrrolidone, N-vinylpyrrolidone, methylvinylpyrrolidone, N- vinylpyridine, N-vinylpiperidone, N- vinylpyrimidine, Substituted complexes such as N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N-vinylmorpholine, N-vinylcaprolactam, N- A cyclic nitrogen vinyl compound having a cyclic structure; (Meth) acryloyl morpholine, N- (meth) acryloylpiperazine, N- (meth) acryloyl aziridine, N- (meth) acryloyl azetidine, N- (Meta) acryloyl-substituted complexes such as N- (meth) acryloylpiperidine, N- (meth) acryloyl azelane, N- A cyclic nitrogen vinyl compound having a cyclic structure; A cyclic nitrogen vinyl compound having a heterocyclic structure having a nitrogen atom and an ethylenically unsaturated bond in the ring such as N-cyclohexylmaleimide and N-phenylmaleimide; Unsubstituted or monoalkyl-substituted (meth) acrylamides such as N-methyl (meth) acrylamide, N-methyl (meth) acrylamide, N-isopropyl (meth) acrylamide and Nt-butyl (meth) acrylamide; (Meth) acrylamide, N, N-diethyl (meth) acrylamide, N, (Meth) acrylamide, N-methyl-N-methyl (meth) acrylamide, N-methyl- Substituted (meth) acrylamides; N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, (Meth) acrylate, N, N-dimethylaminobutyl (meth) acrylate, N, N-diethylaminomethyl (Meth) acrylate, N, N-dibutylaminoethyl (meth) acrylate, N, N-dimethylaminoethyl (Meth) acrylate, t-butylaminoethyl (meth) acrylate and the like; N, N-diethylaminopropyl (meth) acrylamide, N, N-dipropylaminopropyl (meth) acrylamide, N, N-diisopropylaminopropyl (Meth) acrylamide, N-methyl-N-isopropylaminopropyl (meth) acrylamide, N-methyl- N, N-dialkyl-substituted aminopropyl (meth) acrylamides such as amides; N-vinylcarboxylic acid amides such as N-vinyl formamide, N-vinylacetamide and N-vinyl-N-methylacetamide; (Meth) acrylamide, N, N-methylenebis (meth) acrylamide, and the like can be used in combination with one or more of N-methoxymethyl (meth) acrylamide, N-ethoxyethyl (Meth) acrylamides; Unsaturated carboxylic acid nitriles such as (meth) acrylonitrile; And the like.

As the nitrogen-containing vinyl monomer (E-1), those containing no hydroxyl group are preferable, and those containing no hydroxyl group and carboxyl group are more preferable. Examples of such monomers include the above-exemplified monomers such as acrylic monomers containing an N, N-dialkyl substituted amino group or an N, N-dialkyl substituted amide group; Vinyl-substituted lactams such as N-vinyl-2-pyrrolidone, N-vinylcaprolactam and N-vinyl-2-piperidone; N- (meth) acryloyl-substituted cyclic amines such as N- (meth) acryloylmorpholine and N- (meth) acryloylpyrrolidine are preferred.

(Meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-propoxyethyl (meth) acrylate and the like can be given as examples of the alkyl (meth) (Meth) acrylate, 2-ethoxypropyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 2- (Meth) acrylate, 2-propoxypropyl (meth) acrylate, 2-isopropoxypropyl (meth) acrylate, 2-butoxypropyl Propyl (meth) acrylate, 3-butoxypropyl (meth) acrylate, 4-methoxybutyl (meth) acrylate, Acrylate, 4-ethoxybutyl (meth) acrylate, 4-propoxybutyl (meth) acrylate, 4-isopropoxybutyl And the like methacrylate, 4-butoxy-butyl (meth) acrylate.

These alkoxy group-containing alkyl (meth) acrylate monomers have a structure in which the atom of the alkyl group in the alkyl (meth) acrylate is substituted with an alkoxy group.

(Meth) acrylate monomers having (A) a (meth) acrylate monomer having an alkyl group having a carbon number of C4 to C10, (E) a nitrogen-containing vinyl monomer containing no hydroxyl group Is preferably contained in an amount of 1 to 20 parts by weight based on 100 parts by weight. (E-1) a nitrogen-containing vinyl monomer containing no hydroxyl group and an alkyl (meth) acrylate monomer containing (E-2) an alkoxy group may be used alone or in combination of two or more.

(F) The isocyanate compound having three or more functional groups may be a polyisocyanate compound having at least three isocyanate (NCO) groups in one molecule, and examples thereof include hexamethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, A biuret-modified or isocyanurate-modified product of a diisocyanate (e.g., a compound having two NCO groups in one molecule) such as xylylene diisocyanate, a tri- or higher-valent polyol such as trimethylolpropane or glycerin (A compound having an OH group) and the like (polyol modified product).

(F) a trifunctional or higher isocyanate compound is a polyisocyanate compound having at least three isocyanate (NCO) groups in one molecule, in particular, an isocyanurate compound of a hexamethylene diisocyanate compound, an isocyanurate compound of an isophorone diisocyanate compound At least one member selected from the group consisting of an adduct of a hexamethylene diisocyanate compound, an adduct of an isophorone diisocyanate compound, a burette of a hexamethylene diisocyanate compound, and a burette of an isophorone diisocyanate compound Do. (F) The isocyanate compound having three or more functionalities is preferably contained in an amount of 0.4 to 5.0 parts by weight based on 100 parts by weight of the copolymer.

(G) As the crosslinking retarder, β-keto esters such as methyl acetoacetate, ethyl acetoacetate, octyl acetoate, oleyl acetoacetate, lauryl acetoacetate and stearyl acetoate, acetyl acetone, 2,4- Dione, and benzoyl acetone. These are keto-enol tautomeric compounds and block the isocyanate groups of the crosslinking agent in a pressure-sensitive adhesive composition containing a polyisocyanate compound as a crosslinking agent, thereby suppressing excessive viscosity increase or gelation of the pressure-sensitive adhesive composition after blending of the crosslinking agent, Can extend the life of the port.

(G) The crosslinking retarder is preferably a keto-enol tautomer compound, and is preferably at least one selected from the group consisting of acetylacetone and ethyl acetoate.

(G) The crosslinking retarder is preferably contained in an amount of 1.0 to 5.0 parts by weight based on 100 parts by weight of the copolymer.

(H) crosslinking catalyst may be any substance that functions as a catalyst for the reaction (crosslinking reaction) between the copolymer and the crosslinking agent in the case where the polyisocyanate compound is used as the crosslinking agent, and may be an amine compound such as a tertiary amine, , An organic lead compound, an organic zinc compound, and the like.

Examples of tertiary amines include trialkylamines, N, N, N ', N'-tetraalkyldiamines, N, N-dialkylaminoalcohols, triethylenediamine, morpholine derivatives and piperazine derivatives .

Examples of the organotin compounds include dialkyltin oxide, dialkyltin fatty acid salts, and stannous primary fatty acid salts.

(H) The crosslinking catalyst is preferably an organotin compound, and more preferably at least one member selected from the group consisting of dioctyltin oxide and dioctyltin dilaurate.

(H) crosslinking catalyst is preferably contained in an amount of 0.01 to 0.5 parts by weight based on 100 parts by weight of the copolymer.

The antistatic agent (I) is preferably an ionic compound having (I-1) a melting point of 30 to 80 캜 or a quaternary ammonium salt type ionic compound containing an acryloyl group (I-2).

(I-1) an ionic compound having a melting point of 30 to 80 ° C is added to the copolymer, or (I-2) a quaternary ammonium salt type ionic compound containing an acryloyl group Are copolymerized in the copolymer. Since the antistatic agent (I) has a low melting point and also has a long-chain alkyl group, it is presumed that the affinity with the acrylic copolymer is high.

(I-1) As the ionic compound having a melting point of 30 to 80 캜, an ionic compound having a cation and an anion, wherein the cation is a pyridinium cation, an imidazolium cation, a pyrimidinium cation, (PF ₆ ^- ), thiocyanate salt (SCN ^- ), and the like can be used as the anionic cationic cation, cationic cationic cation, and the like. , Alkylbenzenesulfonate (RC ₆ H ₄ SO ₃ ^- ), perchlorate (ClO ₄ ^- ), tetrafluoroborate (BF ₄ ^- ) and the like. It is preferable to be solid at room temperature (for example, 30 ° C), and a melting point of 30 to 80 ° C can be obtained depending on the choice of the chain length of the alkyl group, the position and the number of substituent groups. The cation is preferably a quaternary ammonium onium cation, a quaternary pyridinium cation or a quaternary pyridinium cation such as 1-alkyl pyridinium (the carbon atom at 2-6 may have a substituent or may be unsubstituted) Quaternary imidazolium cation such as 3-dialkyl imidazolium (the carbon atom at the 2, 4 and 5 positions may have a substituent or may be unsubstituted), quaternary ammonium cation such as tetraalkylammonium, etc. .

(I-1) The ionic compound having a melting point of 30 to 80 캜 is preferably contained in an amount of 0.1 to 5.0 parts by weight based on 100 parts by weight of the copolymer.

(I-2) The quaternary ammonium salt type ionic compound containing an acryloyl group is an ionic compound having a cation and an anion, wherein the cation is a (meth) acryloyloxyalkyltrialkylammonium [R ₃ N ⁺ -C (PF ₆ ^- ), an anion of quaternary ammonium containing a (meth) acryloyl group such as _n H _2n -OCOCQ = CH ₂ , where Q = H or CH ₃ , (SCN ^-), organic acid salts (RSO ₃ ^-), perchlorate (ClO ₄ ^-), ₄ fluoride borate (BF ₄ ^-), F-containing already deuyeom (R ^F ₂ N ^-) inorganic or organic anion compounds such as . F-containing already deuyeom (R ^F ₂ N ^-) roneun of R ^F, can be given as a trifluoromethanesulfonyl group, a pentafluorophenyl perfluoroalkyl ethane sulfonyl group, such as an alkane sulfonyl group or a fluoroalkyl sulfonyl group. F contained in an already deuyeom include bis (sulfonyl fluorophenyl) already deuyeom [(FSO _{2) 2} N ^-], bis (trifluoromethane sulfonyl) already deuyeom _{[(CF 3 SO 2) 2 N} - ], bis (Pentafluoroethanesulfonyl) imide salt [(C ₂ F ₅ SO ₂ ) ₂ N ^- ], and the like.

The quaternary ammonium salt type ionic compound containing the (I-2) acryloyl group is preferably copolymerized in the copolymer in an amount of from 0.1 to 5.0% by weight.

Specific examples of the (I) antistatic agent include, but are not particularly limited to, (I-1) Specific examples of the ionic compound having a melting point of 30 to 80 캜 include 1-octylpyridinium hexafluorophosphate, Dodecylpyridinium dodecylbenzenesulfonate, 1-octylpyridinium dodecylbenzenesulfonate, 1-dodecylpyridinium thiocyanate, 1-dodecylpyridinium dodecylbenzene Sulfonic acid salts, 4-methyl-1-octylpyridinium hexafluorophosphate, and the like. Specific examples of the quaternary ammonium salt type ionic compound containing an acryloyl group (I-2) include dimethylaminomethyl (meth) acrylate hexafluorophosphate methyl salt [(CH ₃ ) ₃ N ⁺ CH ₂ OCOCQ = CH ₂ PF ₆ ^- , where Q = H or CH ₃ , dimethylaminoethyl (meth) acrylate bis (trifluoromethanesulfonyl) imide methyl salt [(CH ₃ ) ₃ N ⁺ (CH ₂ ) ₂ OCOCQ = CH ₂ (CF ₃ SO ₂ ) ₂ N ^- , where Q = H or CH ₃ , dimethylaminomethyl methacrylate bis (fluorosulfonyl) imide methyl salt [(CH ₃ ) ₃ N ⁺ CH ₂ OCOCQ = CH _2. (FSO ₂ ) ₂ N ^- , with Q = H or CH ₃ ].

(J) a polyether modified siloxane compound, 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 ].

(J) The polyether-modified siloxane compound is preferably a polyether-modified siloxane compound having an HLB value of 7 to 12. It is also preferable that the polyether-modified siloxane compound (J) is contained in an amount of 0.01 to 0.5 parts by weight based on 100 parts by weight of the copolymer. More preferably, it is 0.1 to 0.5 parts by weight.

HLB 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) .

(J) The blend of the polyether-modified siloxane compound and the pressure-sensitive adhesive composition can improve the adhesive force and the workability of the pressure-sensitive adhesive.

(Meth) acrylate monomer, a (meth) acrylamide monomer, a dialkyl substituted acrylamide monomer, a surfactant, a curing accelerator, a plasticizer, a filler, a curing retarder, a processing aid , An antioxidant, and an antioxidant may be appropriately added. They may be used alone or in combination of two or more.

(A) a (meth) acrylic acid ester monomer having an alkyl group of C4 to C10, (B) a copolymerizable monomer containing a hydroxyl group, (C) a carboxyl group (E) at least one of a nitrogen-containing vinyl monomer containing no hydroxyl group or an alkyl (meth) acrylate monomer containing an alkoxy group, Can be synthesized by polymerization. The polymerization method of the copolymer is not particularly limited, and suitable polymerization methods such as solution polymerization, emulsion polymerization and the like can be used.

When the quaternary ammonium salt type ionic compound (I-2) containing an acryloyl group is used as the antistatic agent (I), the copolymer of the subject used in the pressure-sensitive adhesive composition of the present invention preferably has (A) (B) a copolymerizable monomer containing a hydroxyl group, (C) a copolymerizable monomer containing a carboxyl group, (D) a polyalkylene glycol mono (meth) acrylate monomer, and , (E) polymerizing at least one of a nitrogen-containing vinyl monomer containing no hydroxyl group or an alkyl (meth) acrylate monomer containing an alkoxy group and a quaternary ammonium salt type ionic compound containing an acryloyl group Can be synthesized.

The pressure-sensitive adhesive composition of the present invention comprises the above-mentioned pressure-sensitive adhesive composition, wherein (F) a trifunctional or higher isocyanate compound, (G) a crosslinking retarder, (H) a crosslinking catalyst, (I) an antistatic agent, (J) a polyether- And can be prepared by blending appropriate optional additives. When the quaternary ammonium salt type ionic compound (I-2) containing an acryloyl group is polymerized in the copolymer of the subject, an antistatic agent (I) may be further added to the copolymer or not added.

The copolymer is preferably an acrylic polymer, and it is preferable that the copolymer contains 50 to 100% by weight of an acrylic monomer such as (meth) acrylic acid ester monomer, (meth) acrylic acid or (meth) acrylamide.

The acid value of the acrylic polymer is preferably 0.01 to 8.0. This makes it possible to improve stain resistance and improve the ability to prevent the occurrence of adhesive residue.

Here, " acid value " is one of indices showing the content of acid, and is expressed in mg of potassium hydroxide necessary for neutralizing 1 g of a carboxyl group-containing polymer.

It is preferable that the pressure-sensitive adhesive layer to be crosslinked with the pressure-sensitive adhesive composition has an adhesive force of 0.05 to 0.1 N / 25 mm at a low speed peeling speed of 0.3 m / min and an adhesive force of 1.0 N / 25 mm or less at a high speed peeling speed of 30 m / . As a result, it is possible to obtain a performance in which the adhesive force does not change even by the peeling speed, and it is possible to peel quickly even by high-speed peeling. Further, even when the surface protective film is once peeled off for reattaching, an excessive force is not required and it is easy to peel off from the adherend.

It is preferable that the pressure-sensitive adhesive layer to be crosslinked with the pressure-sensitive adhesive composition has a surface resistivity of 5.0 x 10 ⁺ 10? /? Or less and a peeling electrification voltage of 占 0 to 0.3 kV. In the present invention, "± 0 to 0.3 kV" means 0 to -0.3 kV and 0 to +0.3 kV, that is, -0.3 to +0.3 kV. If the surface resistivity is large, the performance for escaping the static electricity generated by the charging at the time of peeling is lowered. Therefore, by sufficiently reducing the surface resistivity, the peeling electrification voltage caused by the static electricity generated when the adherend is peeled off is reduced Thus, it is possible to suppress the influence on the electric control circuit of the adherend or the like.

The gel fraction of the pressure-sensitive adhesive layer (pressure-sensitive adhesive after crosslinking) to be crosslinked with the pressure-sensitive adhesive composition of the present invention is preferably 95 to 100%. As described above, the gel fraction is so high that the adhesive force is not excessively exerted in peeling at a low speed and the elution of the unpolymerized monomer or oligomer from the copolymer is reduced to improve the durability in reworkability and high temperature and high humidity, Can be suppressed.

In the pressure-sensitive adhesive film of the present invention, the pressure-sensitive adhesive layer formed by crosslinking the pressure-sensitive adhesive composition of the present invention is formed on one side or both sides of the resin film. The surface protective film of the present invention is a surface protective film comprising a pressure sensitive adhesive layer formed by crosslinking the pressure sensitive adhesive composition of the present invention on one side of a resin film. The pressure-sensitive adhesive composition of the present invention has excellent antistatic properties because the components (A) to (J) are well-balanced. Therefore, the pressure-sensitive adhesive composition of the present invention has excellent adhesive force in peeling at a low speed and peeling at a high speed , And also excellent in endurance performance and reworkability (that is, there is no migration of contamination to the adherend after the surface protective film is covered with the ballpoint pen through the pressure-sensitive adhesive layer). 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 or 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.

Antistatic treatment with an antifouling treatment with a silicon-based or fluorine-based releasing agent, a coating agent, fine silica particles, antistatic treatment by application or incorporation of an antistatic agent, etc. can be performed on the surface of the base film opposite to the side where the pressure-

The releasing film is subjected to releasing treatment by a silicone-based, fluorine-based releasing agent or the like on the side to be combined with the adhesive surface of the pressure-sensitive adhesive layer.

Example

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

≪ Preparation of acrylic copolymer >

[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 reactor with nitrogen gas. Thereafter, 100 parts by weight of 2-ethylhexyl acrylate, 0.9 part by weight of 8-hydroxyoctyl acrylate, 0.5 part by weight of acrylic acid, 3 parts by weight of polyethylene glycol monoacrylate and 5 parts by weight of N-vinylpyrrolidone And 60 parts by weight of a solvent (ethyl acetate). Thereafter, 0.1 part by weight of azobisisobutyronitrile as a polymerization initiator was added dropwise over 2 hours and reacted at 65 DEG C for 6 hours to obtain an acrylic copolymer solution (1) of Example 1 having a weight average molecular weight of 500,000 . A part of the acrylic copolymer was sampled and used as a sample for measuring the acid value described later.

[Examples 2 to 9 and Comparative Examples 1 to 9]

The acrylic copolymer solution (1) used in Example 1 was obtained in the same manner as in Example 1 except that the monomers were changed as shown in Table 1 (A) to (E) and (I-2) 2 to 9 and Comparative Examples 1 to 9 were obtained.

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

[Example 1]

1.5 parts by weight of 1-octylpyridinium hexafluorophosphate, 0.2 part by weight of KF-351A (polyether-modified siloxane compound having HLB = 12), 0.5 part by weight of acetyl And 2.5 parts by weight of acetone were added and stirred. Then, 1.5 parts by weight of Coronate HX (isocyanurate of hexamethylene diisocyanate compound) and 0.02 part by weight of dioctyltin dilaurate were added and stirred to obtain a pressure-sensitive adhesive A composition was obtained. This pressure-sensitive adhesive composition was coated on a release film made of a polyethylene terephthalate (PET) film coated with a silicone resin and dried at 90 캜 to remove the solvent to obtain a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer thickness of 25 탆.

Thereafter, the pressure-sensitive adhesive sheet was transferred onto the surface opposite to the antistatic and antifouling treated surface of a polyethylene terephthalate (PET) film having antistatic and antifouling treatment on one side, Sensitive adhesive layer / release film (PET film coated with silicone resin) ".

[Examples 2 to 9 and Comparative Examples 1 to 9]

The surface protection films of Examples 2 to 9 and Comparative Examples 1 to 9 were prepared in the same manner as in the surface protective film of Example 1 except that the additives were changed to the compositions of (F) to (J) A film was obtained.

Tables 1 and 2 show the results obtained by dividing all the tables showing the blend ratios of the respective components into two, and the values of the parts by weight obtained by taking the total of the (A) groups as 100 parts by weight are enclosed in parentheses. Tables 3 and 4 show the compound names of the weak symbols of the respective components used in Tables 1 and 2. 351A, KF-352A, KF-353, and KF-351A are trade names of Nippon Polyurethane Industry Co., Ltd. and Takenate (registered trademark) D-140N are trade names of Mitsui Chemicals, -640 and X-22-6191 are trade names of Shin-Etsu Chemical Co.,

In Table 1, the quaternary ammonium salt type ionic compound (I-2) acryloyl group-containing copolymer (I-2) copolymerized in the copolymer (I) in the antistatic agent has a melting point of 30 to 80 ° C The phosphorus ionic compound is described in a different column. The I-1-8 used in Comparative Example 9 had a melting point of less than 30 占 폚 (liquid at room temperature), but for simplicity, it is described in the same column as (I-1).

<Test Method and Evaluation>

After the surface protective films of Examples 1 to 9 and Comparative Examples 1 to 9 were aged for 7 days in an atmosphere of 23 ° C and 50% RH, a release film (PET resin film coated with a silicone resin) was peeled off to form a pressure- The thus-labeled sample was used as a sample for measuring the gel fraction and the surface resistivity.

The surface protective film on which the pressure-sensitive adhesive layer was exposed was adhered to the surface of the polarizing plate attached to the liquid crystal cell via the pressure-sensitive adhesive layer, allowed to stand for one day, autoclaved at 50 DEG C and 5 atm for 20 minutes, The sample was allowed to stand for 12 hours and used as a sample for measuring the adhesive force, peeling electrification voltage and durability.

<Acid value>

The acid value of the acrylic polymer was determined by dissolving the sample in a solvent (a mixture of diethyl ether and ethanol in a volumetric ratio of 2: 1) and using an electric potential difference automatic titrator (AT-610, manufactured by Kyoto Electronics Manufacturing Co., Ltd.) Potentiometric titration was performed with a potassium hydroxide ethanol solution having a concentration of about 0.1 mol / L using an titration apparatus, and the amount of the potassium hydroxide ethanol solution necessary for neutralizing the sample was measured. From the following equation, the acid value was calculated.

Acid value = (B x f x 5.611) / S

B = amount (ml) of 0.1 mol / l potassium hydroxide ethanol solution used for titration,

f = 0.1 mol / l A factor of the potassium hydroxide ethanol solution

S = mass of solids in the sample (g)

<Gel fraction>

After the completion of the aging, the mass of the sample to be measured before the application to the polarizing plate is precisely measured, and after soaking in toluene for 24 hours, the glass is filtered through a 200-mesh wire net. Thereafter, the filtrate was dried at 100 DEG C for 1 hour, and the mass of the residue was accurately measured. From the following equation, the gel fraction of the pressure-sensitive adhesive layer (pressure-sensitive adhesive after crosslinking) was calculated.

Gel fraction (%) = Insoluble part mass (g) / Adhesive mass (g) × 100

<Adhesion>

The measurement specimen obtained by bonding the surface protective film having a width of 25 mm to the surface of the polarizing plate obtained above was measured with a tensile tester in the direction of 180 ° at a low rate of peeling (0.3 m / min) and a high rate of peeling (30 m / min ), And the peel strength measured as the adhesive strength.

<Surface resistivity>

After the aging, a peeling film (PET resin film coated with silicone resin) was peeled off to form a pressure-sensitive adhesive layer before being adhered to the polarizing plate. Using a resistivity meter HILESTAR UP-HT450 (manufactured by Mitsubishi Chemical Engineering Co., Ltd.) Was measured.

<Peeling Voltage>

The voltage (voltage) generated as a result of charging the polarizing plate was measured with a high-precision electrostatic sensor SK-035, SK-200 (manufactured by KYOSEN CO., LTD.) At 180 ° peeling at a tensile speed of 30 m / , And the maximum value of the measured value was taken as the peeling electrification voltage.

<Workability>

The surface protective film of the measurement specimen obtained above was overlaid with a ballpoint pen (load: 500 g, three round trips), and then the surface protective film was peeled off from the polarizing plate to observe the surface of the polarizing plate. The evaluation target standard was "◯" when no pollution was observed on the polarizer, "Δ" when the pollution was confirmed to be at least partially along the locus padded with the ballpoint pen, the contamination was confirmed along the locus of the ballpoint pen, Quot ;, and the case where the release of the pressure-sensitive adhesive was confirmed also from &quot; X &quot;.

<Durability>

The measurement sample thus obtained was allowed to stand in an atmosphere at 60 DEG C and 90% RH for 250 hours, taken out at room temperature, left for another 12 hours, and then measured for adhesion to confirm that there was no clear increase compared with the initial adhesion. The evaluation target standard was evaluated as &quot;? &Quot; when the adhesion after the test was 1.5 times or less than the initial adhesion, and &quot; X &quot;

Table 5 shows the evaluation results. In addition, the surface resistivity 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 surface protective films of Examples 1 to 9 each had an adhesive force of 0.05 to 0.1 N / 25 mm at a low speed peeling rate of 0.3 m / min, an adhesive force of 1.0 N / 25 mm or less at a high peeling rate of 30 m / After the resistivity was 5.0 × 10 ⁺ 10 Ω / □ or less and the peeling electrification voltage was ± 0 to 0.3 kV and the surface protective film was covered with a ballpoint pen through the pressure-sensitive adhesive layer, there was no stain on the adherend, % RH for 250 hours. In these examples, the peeling electrification voltage was reduced to ± 0 to 0.2 kV.

That is, (1) balance of adhesive force at a low speed peeling speed and a high speed peeling speed, (2) prevention of occurrence of adhesive residue, (3) excellent antistatic performance, and (4) At the same time.

The surface protective film of Comparative Example 1 does not contain the polyalkylene glycol mono (meth) acrylate monomer (D) and the nitrogen-containing vinyl monomer or alkoxy group-containing alkyl (meth) acrylate monomer, The adhesion at a peeling speed of 0.3 m / min was low, the peeling electrification voltage was high, and the reworkability was slightly off.

In the surface protective film of Comparative Example 2, the hydroxyl group-containing monomer (B) is underexpanded, (D) the polyalkylene glycol mono (meth) acrylate monomer is too low, and the (E) nitrogen-containing vinyl monomer or alkoxy group- ) Acrylate monomer, (F) the isocyanate compound was excessive, (J) the polyether-modified siloxane compound had a low HLB value, or the adhesive force at a low speed peeling rate of 0.3 m / min and the high peeling rate of 30 m / min, the peeling electrification voltage was high, the reworkability and durability were poor, and the gel fraction was low.

(D) the polyalkylene glycol mono (meth) acrylate monomer was excessively contained, and (E) the nitrogen-containing (meth) acrylic ester monomer (J) the HLB value of the polyether-modified siloxane compound is excessive, the acid value of the acrylic polymer is high, and the adhesive strength at a low speed peeling rate of 0.3 m / min And high-speed peeling speed of 30 m / min were too large, the surface resistivity was high, the peeling electrification voltage was high, and the reworkability and durability were poor.

In the surface protective film of Comparative Example 4, (C) the acid-containing monomer is low, (D) the polyalkylene glycol mono (meth) acrylic acid ester monomer is not contained, and the nitrogen-containing vinyl monomer or alkoxy group- (Meth) acrylate monomer was low, the adhesion at low speed peeling rate of 0.3 m / min was low, the peeling electrification voltage was high, and the reworkability and durability were poor.

(C) the acid-containing monomer was excessive; (D) the polyalkylene glycol mono (meth) acrylate monomer was inferior; (E) the nitrogen-containing (F) the isocyanate compound was low, or the acrylic polymer had a high acid value, an adhesive strength at a low speed peeling speed of 0.3 m / min and a high peeling speed The adhesive force at 30 m / min was excessively large, the peeling electrification voltage was high, the reworkability and durability were poor, and the gel fraction was low.

The surface protective film of Comparative Example 6 could not be coated because the (G) crosslinking retarder was not blended, the pot life was too short, and the crosslinking proceeded before application.

The surface protective film of Comparative Example 7 is a surface protective film of Comparative Example 7 in which (A) MA having an alkyl group of C1 is contained in the (meth) acrylic acid ester monomer having an alkyl group, (B) the monomer having hydroxyl group is excessive, (D) the polyalkylene glycol mono (Meth) acrylate monomer and (E) a nitrogen-containing vinyl monomer or an alkoxy group-containing alkyl (meth) acrylate monomer, The adhesive force was too high at the high speed peeling speed of 30 m / min, the surface resistivity was high, the peeling electrification voltage was high, and the reworkability and durability were poor.

In the surface protective film of Comparative Example 8, the polyalkylene glycol mono (meth) acrylic acid ester monomer (D) was excessive, and neither the nitrogen-containing vinyl monomer nor the alkoxy group-containing alkyl (meth) acrylate monomer was contained, (J) the polyether-modified siloxane compound was not blended, the adhesive force at a low speed peeling rate of 0.3 m / min and the adhesive force at a high-speed peeling rate of 30 m / min were excessively large, the surface resistivity was high, The workability was slightly off.

In the surface protective film of Comparative Example 9, the polyalkylene glycol mono (meth) acrylate monomer (D) and the nitrogen-containing vinyl monomer or alkoxy group-containing alkyl (meth) (J) the polyether-modified siloxane compound is excessive, the adhesive strength at low speed peeling rate of 0.3 m / min is low, the peeling electrification voltage is high, Slightly declining, durable.

As described above, in the surface protective films of Comparative Examples 1 to 9, (1) balance of adhesive force at a low rate of peeling and high rate of peeling, (2) prevention of occurrence of residual adhesive, (3) , And (4) all the required performance of the rework performance.

Claims (27)

(A) a (meth) acrylic acid ester monomer having an alkyl group of C4 to C10, (B) a copolymerizable monomer containing a hydroxyl group, (C) a copolymerizable monomer containing a carboxyl group, and (D) a polyalkylene glycol (E) a mono (meth) acrylate monomer, and (E) an acrylic polymer which is a copolymer comprising at least one of nitrogen-containing vinyl monomers or alkoxy group-containing alkyl (meth) (G) a crosslinking retarder, (H) a crosslinking catalyst, (I) an antistatic agent, and (J) a polyether-modified siloxane compound, wherein the acrylic polymer has an acid value of 0.01 To 8.0. The method according to claim 1,
(Meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, At least one compound selected from the group consisting of ethyl (meth) acrylate, N-hydroxy (meth) acrylamide, N-hydroxymethyl (meth) acrylamide and N-hydroxyethyl
Wherein 0.1 to 5.0 parts by weight of the copolymerizable monomer containing the hydroxyl group (B) is contained in 100 parts by weight of the (meth) acrylic ester monomer having (A) the alkyl group of C4 to C10, (Meth) acrylate, 4-hydroxybutyl (meth) acrylate and 8-hydroxyoctyl (meth) acrylate in the copolymerizable monomer containing hydroxyl group is 0 to 0.9 weight Negative pressure sensitive adhesive composition. 3. The method according to claim 1 or 2,
Wherein the copolymerizable monomer containing a carboxyl group is at least one selected from the group consisting of (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- (Meth) acrylate mono (meth) acrylate, 2- (meth) acryloyloxyethyltetrahydrophthalic acid,
The pressure-sensitive adhesive composition according to any one of (1) to (3), wherein the (A) alkylene group contains 0.35 to 1.0 part by weight of a copolymerizable monomer containing the carboxyl group (C) relative to 100 parts by weight of the (meth) acrylic acid ester monomer having C4 to C10 carbon atoms. 3. The method according to claim 1 or 2,
Wherein the polyalkylene glycol mono (meth) acrylate monomer (D) is at least one monomer selected from the group consisting of polyalkylene glycol mono (meth) acrylate, methoxypolyalkylene glycol (meth) acrylate, ethoxypolyalkylene glycol (A) 1 to 20 parts by weight based on 100 parts by weight of (meth) acrylic acid ester monomers having an alkyl group of C4 to C10 in the alkyl group. 3. The method according to claim 1 or 2,
Wherein the nitrogen-containing vinyl monomer or alkoxy group-containing alkyl (meth) acrylate monomer (E) containing no hydroxyl group is used in an amount of 100 parts by weight or more based on 100 parts by weight of the (meth) acrylic acid ester monomer having an alkyl group of C4- 1 to 20 parts by weight of a pressure-sensitive adhesive composition. 3. The method according to claim 1 or 2,
Wherein the isocyanurate compound of the hexamethylene diisocyanate compound (F), the isocyanurate compound of the isophorone diisocyanate compound, the adduct of the hexamethylene diisocyanate compound, the isophorone diisocyanate compound of the hexamethylene diisocyanate compound , A bidentate of hexamethylene diisocyanate compound, and a burette of isophorone diisocyanate compound,
And 0.4 to 5.0 parts by weight of the (F) trifunctional or higher isocyanate compound relative to 100 parts by weight of the copolymer. 3. The method according to claim 1 or 2,
Wherein the antistatic agent (I) is an ionic compound having a melting point of 30 to 80 DEG C, which is contained in an amount of 0.1 to 5.0 parts by weight based on 100 parts by weight of the copolymer, or 0.1 to 5.0% Wherein the quaternary ammonium salt type ionic compound is an acryloyl group-containing quaternary ammonium salt type ionic compound. 3. The method according to claim 1 or 2,
The polyether-modified siloxane compound (J) is a polyether-modified siloxane compound having an HLB value of 7 to 12,
0.01 to 0.5 parts by weight of the polyether-modified siloxane compound (J) per 100 parts by weight of the copolymer. 3. The method according to claim 1 or 2,
Wherein the (G) crosslinking retarder is a keto-enol tautomeric compound,
1.0 to 5.0 parts by weight of the crosslinking retarder (G) is added to 100 parts by weight of the copolymer. 3. The method according to claim 1 or 2,
Wherein the (H) crosslinking catalyst is an organotin compound,
Wherein the crosslinking catalyst (H) is contained in an amount of 0.01 to 0.5 parts by weight based on 100 parts by weight of the copolymer. 3. The method according to claim 1 or 2,
Wherein the pressure-sensitive adhesive layer to be crosslinked with the pressure-sensitive adhesive composition has an adhesive force of 0.05 to 0.1 N / 25 mm at a low speed peeling speed of 0.3 m / min and an adhesive force of 1.0 N / 25 mm or less at a high speed peeling speed of 30 m / min. 3. The method according to claim 1 or 2,
Wherein the pressure-sensitive adhesive layer to be crosslinked with the pressure-sensitive adhesive composition has a surface resistivity of 5.0 x 10 ⁺ 10? /? Or less and a peeling electrification voltage of +/- 0 to 0.3 kV. A pressure-sensitive adhesive film comprising a pressure-sensitive adhesive layer formed by crosslinking the pressure-sensitive adhesive composition of claim 1 or 2 on one side or both sides of a resin film. delete delete delete delete delete delete delete delete delete delete A surface protective film comprising a pressure sensitive adhesive layer crosslinked with the pressure sensitive adhesive composition of claim 1 or 2 formed on one side of a resin film, characterized in that after the surface protective film is covered with a ballpoint pen through the pressure sensitive adhesive layer, No surface protection film. 25. The method of claim 24,
A surface protective film used as a surface protective film of a polarizing plate. 25. The method of claim 24,
Wherein a surface of the resin film opposite to the side on which the pressure-sensitive adhesive layer is formed is subjected to antistatic treatment and antifouling treatment. 26. The method of claim 25,
Wherein a surface of the resin film opposite to the side on which the pressure-sensitive adhesive layer is formed is subjected to antistatic treatment and antifouling treatment.