KR102125203B1 - Adhesive composition and surface protection film - Google Patents

Abstract

The present invention provides a pressure-sensitive adhesive composition and a surface protection film having antistatic performance and having excellent balance of adhesion, long pot life, and excellent durability and reworkability at low-speed peeling speed and high-speed peeling speed. (A) (meth)acrylic acid ester monomers having C4 to C18 carbon atoms in the alkyl group, (B) copolymerizable monomer containing a hydroxyl group, (C) copolymerizable monomer containing a carboxyl group, (D) polyalkylene glycol mono (metha) )Acrylic acid ester monomer, (E) an acrylic polymer of a copolymer containing a hydroxyl-containing nitrogen-containing vinyl monomer or an alkoxy group-containing alkyl (meth)acrylate monomer, and (F) a bifunctional or higher isocyanate compound, ( G) It contains a crosslinking accelerator of a metal chelate compound, (H) a ketoenol tautomeric compound, (I) an antistatic agent, and (J) a polyether-modified siloxane compound.

Description

Adhesive composition and surface protection film {ADHESIVE COMPOSITION AND SURFACE PROTECTION FILM}

The present invention relates to an adhesive composition and a surface protection film. More specifically, the pressure-sensitive adhesive composition and surface for a surface protective film of a polarizing plate having antistatic performance, excellent low-speed peeling rate and high-speed peeling rate, excellent adhesion balance, long pot life, and excellent durability and reworkability. It relates to providing a protective film.

As a pressure-sensitive adhesive for optical use, an acrylic pressure-sensitive adhesive composed of a copolymer obtained by copolymerizing an acrylic monomer having an alkyl (meth)acrylate as a main component and having a hydroxyl group or a carboxyl group as a functional group is preferably used. Moreover, it is necessary that various physical properties, such as adhesive force of an adhesive, are adjusted suitably. In particular, the pressure-sensitive adhesive for the surface protection film, etc., is suitable for a low-speed peeling speed and a high-speed peeling speed suitable for bonding the surface-protecting film with an automatic bonding device so as to be suitable for a manufacturing process of factory production. . In addition, in addition to the balance of the adhesive force, there is a need for an adhesive having a long pot life and excellent durability, rework property, and antistatic property.

Various physical properties of these adhesives are crosslinked using isocyanate-based crosslinking agents, epoxy-based crosslinking agents, etc., which react with functional groups such as hydroxyl groups and carboxyl groups contained in the acrylic adhesives made of copolymers to adjust adhesive strength or cohesive strength, etc. Things are being done.

Conventionally, as a crosslinking agent of an acrylic adhesive, an isocyanate crosslinking agent is used universally. In addition, in the crosslinking reaction using an isocyanate-based crosslinking agent, a metal chelate is frequently used as a catalyst for promoting the crosslinking reaction.

Generally, dibutyl tin dilaurate, an organic tin compound, has been used as a catalyst for the crosslinking reaction in that the reaction rate of the crosslinking reaction is excellent, but it is avoided to use the dibutyl tin compound because it exhibits harmful toxicity. have.

For this reason, a crosslinking catalyst that is inexpensive and excellent in the reaction rate of the crosslinking reaction, which is a substitute for the dibutyl tin compound used in combination with an isocyanate crosslinking agent, has been demanded, but it is difficult to find.

Among them, Patent Literature 1 discloses that iron chelate is preferred among metal chelates as a crosslinking catalyst used in combination with an isocyanate-based crosslinking agent, and tris(acetylacetonate) iron is particularly preferred because of its excellent catalytic activity.

However, the acrylic pressure-sensitive adhesive composition containing a cross-linking catalyst gradually progresses the cross-linking reaction even while left at room temperature. For this reason, in the industrial production of the pressure-sensitive adhesive, after the raw materials of the pressure-sensitive adhesive composition are blended, a crosslinking catalyst and a reaction retardant are used in combination to generally stop the crosslinking reaction until the time for starting the crosslinking reaction.

Regarding the use of this crosslinking catalyst and the reaction retarder, Patent Document 2 is a method for producing polyurethane, which is a mixture of at least one metal acetylacetonate and acetylacetone, and the metal acetylacetonate and the acetylacetone. It is disclosed to use a reaction urethane mixture comprising a catalyst system with a weight ratio of 2:1.

Japanese Patent Application Publication No. 2011-001440 Japanese Patent Application Publication No. 2008-285681

In the pressure-sensitive adhesive composition described in Patent Literature 1, the amount of a metal compound (crosslinking catalyst) added to a copolymer containing (meth)acrylate as a constituent monomer unit and containing a hydroxyl group and a carboxyl group is disclosed. There is no description. In addition, in Patent Document 1, a method of using a reaction retarder, a method of adding a viscosity-inhibiting solvent, a cross-linking agent blocking functional groups such as blocked isocyanate as a method of suppressing the rate of increase in viscosity after the crosslinking agent is blended in the pressure-sensitive adhesive composition is used Methods and the like are illustrated, but there is no specific explanation.

Further, in Patent Document 2, even if a metal acetylacetonate catalyst such as iron or copper, which is highly active at low temperature, is used, metal acetylacetonate and acetylacetone having excellent stability and good catalytic activity, which do not cause premature curing, are not used. A method of manufacturing polyurethane using an included catalyst system is disclosed.

However, in the method described in Patent Document 2, the weight ratio of the metal acetylacetonate and acetylacetone is 2:1, but even if this blending ratio is applied to the manufacturing process of the acrylic pressure-sensitive adhesive, it was not possible to temporarily stop the crosslinking reaction.

The present invention has been made in view of the above circumstances, and does not use an organotin compound, has antistatic performance, is excellent in balance of adhesion in low-speed peeling speed and high-speed peeling speed, and also has a long pot life and durability. And it is an object to provide a pressure-sensitive adhesive composition for a surface protective film and a surface protective film of a polarizing plate excellent in rework property.

In order to solve the said subject, this invention is (A) At least 1 sort(s) of the (meth)acrylic acid ester monomer of C4~C18 alkyl group, and (B) a copolymerizable monomer containing a hydroxyl group as a copolymerizable monomer group, (C) a copolymerizable monomer containing a carboxyl group, (D) a polyalkylene glycol mono(meth)acrylic acid ester monomer, and (E) a nitrogen-containing vinyl monomer containing no hydroxyl group or an alkyl (meth)acrylate containing an alkoxy group. It consists of an acrylic polymer of the copolymer containing at least 1 sort(s) selected from the copolymerizable monomer group consisting of a monomer, (F) a bifunctional or higher isocyanate compound, (G) a crosslinking accelerator of a metal chelate compound, and (H) ketoene. An adhesive composition further comprising an all tautomeric compound, (I) an ionic compound having an melting point of 25 to 50°C as an antistatic agent, and/or an acryloyl group-containing ionic compound, and (J) a polyether-modified siloxane compound to provide.

In addition, with respect to the total 100 parts by weight of the acrylic polymer of the copolymer,

The acrylic polymer

50 to 95 parts by weight of the (meth)acrylic acid ester monomer having C4 to C18 carbon atoms in the alkyl group (A),

0.1 to 10 parts by weight of the copolymerizable monomer containing the hydroxyl group (B),

0 to 1.0 parts by weight of the copolymerizable monomer (C) containing a carboxyl group,

0 to 50 parts by weight of the (D) polyalkylene glycol mono (meth) acrylic acid ester monomer,

The (E) contains 0 to 20 parts by weight of a nitrogen-containing vinyl monomer or an alkoxy group-containing alkyl (meth) acrylate monomer containing no hydroxyl group,

The pressure-sensitive adhesive composition

(F) 0.1 to 10 parts by weight of the bifunctional or higher isocyanate compound,

0.001 to 0.5 parts by weight of the crosslinking accelerator of the (G) metal chelate compound,

It contains 0.1 to 200 parts by weight of the (H) ketoenol tautomeric compound,

As the antistatic agent (I), 0.05 to 5.0 parts by weight of the total of the antistatic agent contained in the pressure-sensitive adhesive composition and the antistatic agent copolymerized in the copolymer,

It is preferable to contain 0.01 to 1.0 part by weight of the polyether-modified siloxane compound (J).

In addition, (B) the copolymerizable monomer containing a hydroxyl group is 8-hydroxyoctyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxy At least one selected from the group of compounds consisting of hydroxyethyl (meth)acrylate, N-hydroxy (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, and N-hydroxyethyl (meth)acrylamide. desirable.

In addition, (C) the copolymerizable monomer containing a carboxyl group is (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, 2 -(Meth)acryloyloxypropylhexahydrophthalic acid, 2-(meth)acryloyloxyethylphthalic acid, 2-(meth)acryloyloxyethylsuccinic acid, 2-(meth)acryloyloxyethylmaleic acid, It is preferable that it is at least 1 sort(s) or more selected from the compound group which consists of carboxypolycaprolactone mono(meth)acrylate and 2-(meth)acryloyloxyethyl tetrahydrophthalic acid.

In addition, the (D) polyalkylene glycol mono (meth) acrylic acid ester monomers are polyalkylene glycol mono (meth) acrylate, methoxy polyalkylene glycol (meth) acrylate, ethoxy polyalkylene glycol (meth) It is preferable that it is at least one or more selected from acrylates.

Further, it is preferable that the (E) nitrogen-containing vinyl monomer or alkoxy group-containing alkyl (meth)acrylate monomer containing the hydroxyl group contains at least one or more of the monomers in which the acrylic polymer is the copolymerizable monomer group.

Moreover, it is preferable that it is a compound produced|generated by reacting a diisocyanate compound and a diol compound with a bicyclic aliphatic isocyanate compound as said (F) bifunctional or more isocyanate compound as a bifunctional isocyanate compound. The diisocyanate compound is an aliphatic diisocyanate, and is preferably one selected from the group of compounds consisting of tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate. Further, as the diol compound, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-ethyl Compound consisting of -2-butyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol monohydroxypivalate, polyethylene glycol, and polypropylene glycol It is preferably made of one selected from the group.

In addition, as the above-mentioned (F) bifunctional or higher isocyanate compound, trifunctional isocyanate compounds include isocyanurate bodies of hexamethylene diisocyanate compounds, isocyanurate bodies of isophorone diisocyanate compounds, and hexamethylene diisocyanate compounds. Duct body, adduct of isophorone diisocyanate compound, burette body of hexamethylene diisocyanate compound, burette body of isophorone diisocyanate compound, isocyanurate body of tolylene diisocyanate compound, isocylate of xylylene diisocyanate compound Among the compound group consisting of an anurate body, an isocyanurate body of a hydrogenated xylylene diisocyanate compound, an adduct body of a tolylene diisocyanate compound, an adduct body of a xylylene diisocyanate compound, and an adduct body of a hydrogenated xylylene diisocyanate compound It is preferable that it is at least one selected.

In addition, the (I) antistatic agent is an ionic compound having a melting point of 25 to 50°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, and/or 0.1 to 5.0% by weight in the copolymer. It is preferably a copolymerized acryloyl group-containing ionic compound.

Moreover, it is preferable that the HLB value of the said (J) polyether modified siloxane compound is 7-15.

Further, the pressure-sensitive adhesive layer formed by crosslinking the pressure-sensitive adhesive composition has a low-speed peeling rate of 0.3 m/min to 0.05 to 0.1 N/25 mm, and a high-speed peeling speed of 30 m/min to have an adhesive strength of 1.0 N/25 mm or less. Do.

Moreover, it is preferable that the surface resistivity of the pressure-sensitive adhesive layer formed by crosslinking the pressure-sensitive adhesive composition is 9.0×10 ⁺¹⁰ Ω/□ or less, and the peeling voltage is ±0 to 0.5 MPa.

In addition, the present invention provides a pressure-sensitive adhesive film characterized in that the pressure-sensitive adhesive layer formed by crosslinking the pressure-sensitive adhesive composition is formed on one side or both sides of the resin film.

In addition, the present invention is a surface protective film formed by forming an adhesive layer formed by crosslinking the adhesive composition on one side of a resin film, after the adhesive layer is overlaid on the surface protective film with a ballpoint pen, the adherend is transferred to the adherend. It provides a surface protection film characterized in that there is no.

Moreover, the surface protection film of this invention can be used as a use of the surface protection film of a polarizing plate.

In addition, it is preferable that the surface protection film of the present invention is provided with an antistatic and antifouling treatment on a surface opposite to the side on which the pressure-sensitive adhesive layer is formed on the resin film.

According to the present invention, all the performance required for the pressure-sensitive adhesive layer of the surface protection film, which could not be solved in the prior art, can be satisfied without using an organotin compound, and also excellent antistatic performance is obtained, and the adhesive residue It became possible to prevent occurrence. Specifically, while maintaining excellent antistatic performance, it is possible to reduce the amount of the antistatic agent added, and further improve the performance of preventing the generation of adhesive residues.

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

The pressure-sensitive adhesive composition of the present invention has at least one of (A) an alkyl group having (C4 to C18) C4-C18 (meth)acrylic acid ester monomer, a copolymerizable monomer group (B) a copolymerizable monomer containing a hydroxyl group, and (C ) A copolymerizable monomer containing a carboxyl group, (D) a polyalkylene glycol mono(meth)acrylic acid ester monomer, and (E) a nitrogen-containing vinyl monomer containing no hydroxyl group or an alkyl (meth)acrylate monomer containing an alkoxy group. Made of an acrylic polymer of a copolymer containing at least one selected from the group of copolymerizable monomers, (F) a bifunctional or higher isocyanate compound, (G) a crosslinking accelerator of a metal chelate compound, and (H) ketoenol tautomerization. It is characterized by further containing an isomer compound, (I) an ionic compound having an melting point of 25 to 50°C as an antistatic agent, and/or an acryloyl group-containing ionic compound, and (J) a polyether-modified siloxane compound.

Further, with respect to 100 parts by weight of the total of the acrylic polymer of the copolymer, the acrylic polymer contains (A) 50 to 95 parts by weight of the (meth)acrylic acid ester monomer having C4 to C18 alkyl groups, and (B) a hydroxyl group. 0.1 to 10 parts by weight of the copolymerizable monomer, (C) 0 to 1.0 part by weight of the copolymerizable monomer containing a carboxyl group, and (D) 0 to 50 parts by weight of the polyalkylene glycol mono(meth)acrylic acid ester monomer. , (E) It is preferable to contain 0 to 20 parts by weight of a nitrogen-containing vinyl monomer containing no hydroxyl group or an alkoxy group-containing alkyl (meth)acrylate monomer.

Moreover, with respect to the total 100 parts by weight of the acrylic polymer of the copolymer, the pressure-sensitive adhesive composition may contain 0.1 to 10 parts by weight of the (F) bifunctional or higher isocyanate compound, and (G) 0.001 to 0.5 parts by weight of the crosslinking accelerator of the metal chelate compound. , (H) 0.1 to 200 parts by weight of the ketoenol tautomeric compound, and (I) 0.05 to the total of the antistatic agent contained in the pressure-sensitive adhesive composition as the antistatic agent and the antistatic agent copolymerized in the copolymer. It is preferable to contain 5.0 parts by weight and 0.01 to 1.0 parts by weight of the polyether-modified siloxane compound (J).

(A) Examples of the (meth)acrylic acid ester monomers having C4 to C18 carbon atoms in the alkyl group include butyl (meth)acrylate, isobutyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, and heptyl (Meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth) Acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate , Hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, myristyl (meth)acrylate, isomiristyl (meth)acrylate, cetyl (meth)acrylate, iso Cetyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, and the like.

When the total amount of the acrylic polymer of the copolymer is 100 parts by weight, it is preferable that the (meth)acrylic acid ester monomer having C4 to C18 carbon atoms in the alkyl group is contained in a proportion of 50 to 95 parts by weight.

(B) As a copolymerizable monomer containing a hydroxyl group, 8-hydroxyoctyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxy Hydroxyalkyl (meth)acrylates such as ethyl (meth)acrylate, N-hydroxy (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, N-hydroxyethyl (meth)acrylamide, etc. And hydroxyl group-containing (meth)acrylamides.

8-hydroxyoctyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, N-hydroxy (meth) ) It is preferable that it is at least one or more selected from the compound group consisting of acrylamide, N-hydroxymethyl (meth)acrylamide, and N-hydroxyethyl (meth)acrylamide.

When the total amount of the acrylic polymer of the copolymer is 100 parts by weight, it is preferable to contain the copolymerizable monomer containing the hydroxyl group (B) in a proportion of 0.1 to 10 parts by weight.

(C) Copolymerizable monomers containing carboxyl groups include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, 2-(meth)acryloyloxyethylhexahydrophthalic acid, 2-(meth )Acryloyloxypropylhexahydrophthalic acid, 2-(meth)acryloyloxyethylphthalic acid, 2-(meth)acryloyloxyethylsuccinic acid, 2-(meth)acryloyloxyethylmaleic acid, carboxypolycapro It is preferable that it is at least 1 sort(s) or more selected from the compound group which consists of lactone mono(meth)acrylate and 2-(meth)acryloyloxyethyl tetrahydrophthalic acid.

When the total amount of the acrylic polymer of the copolymer is 100 parts by weight, it is preferable to contain the copolymerizable monomer containing the carboxyl group (C) in a proportion of 0 to 1.0 parts by weight. In the pressure-sensitive adhesive layer according to the present invention, it is not necessary to contain the copolymerizable monomer containing (C) a carboxyl group in the pressure-sensitive adhesive composition.

(D) As the polyalkylene glycol mono(meth)acrylic acid ester monomer, a compound in which one hydroxyl group is esterified as a (meth)acrylic acid ester among a plurality of hydroxyl groups of the polyalkylene glycol may be sufficient. Since the (meth)acrylic acid ester group becomes a polymerizable group, it can be copolymerized with the main polymer. The other hydroxyl group may be 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, but are not limited to, ethylene group, propylene group, butylene group, and the like. The polyalkylene glycol may be a copolymer of two or more 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, polyethylene glycol-polypropylene glycol-polybutylene glycol, and the like. The copolymer may be a block copolymer or a random copolymer.

(D) It is preferable that the average repetition number of the alkylene oxide which the polyalkylene glycol mono(meth)acrylic acid ester monomer comprises a polyalkylene glycol chain is 3-14. The "average number of repeats of alkylene oxide" means that the alkylene oxide unit is repeated in the part of the "polyalkylene glycol chain" contained in the molecular structure of (D) the polyalkylene glycol mono(meth)acrylic acid ester monomer. It is the average number.

(D) Polyalkylene glycol mono(meth)acrylic acid ester monomers include polyalkylene glycol mono(meth)acrylate, methoxypolyalkylene glycol (meth)acrylate, and ethoxypolyalkylene glycol (meth)acrylic. It is preferable that it is at least 1 sort(s) or more selected from a rate.

More specifically, polyethylene glycol-mono(meth)acrylate, polypropylene glycol-mono(meth)acrylate, polybutylene glycol-mono(meth)acrylate, polyethylene glycol-polypropylene glycol-mono(meth)acrylic Rate, polyethylene glycol-polybutylene glycol-mono(meth)acrylate, polypropylene glycol-polybutylene glycol-mono(meth)acrylate, polyethylene glycol-polypropylene glycol-polybutylene glycol-mono(meth)acrylic Rate; Methoxypolyethylene glycol-(meth)acrylate, methoxypolypropylene glycol-(meth)acrylate, methoxypolybutylene glycol-(meth)acrylate, methoxy-polyethylene glycol-polypropylene glycol-(meth)acrylic Rate, methoxy-polyethylene glycol-polybutylene glycol-(meth)acrylate, methoxy-polypropylene glycol-polybutylene glycol-(meth)acrylate, methoxy-polyethylene glycol-polypropylene glycol-polybutylene Glycol-(meth)acrylate; Ethoxypolyethylene glycol-(meth)acrylate, ethoxypolypropylene glycol-(meth)acrylate, ethoxypolybutylene glycol-(meth)acrylate, ethoxy-polyethylene glycol-polypropylene glycol-(meth)acrylic Rate, ethoxy-polyethylene glycol-polybutylene glycol-(meth)acrylate, ethoxy-polypropylene glycol-polybutylene glycol-(meth)acrylate, ethoxy-polyethylene glycol-polypropylene glycol-polybutylene Glycol-(meth)acrylate and the like.

When the total amount of the acrylic polymer of the copolymer is 100 parts by weight, it is preferable to contain the polyalkylene glycol mono(meth)acrylic acid ester monomer (D) in a proportion of 0 to 50 parts by weight. In the pressure-sensitive adhesive layer according to the present invention, it is not necessary to contain the (D) polyalkylene glycol mono(meth)acrylic acid ester monomer in the pressure-sensitive adhesive composition.

Among (E), examples of the vinyl monomer containing (E-1) include a vinyl monomer containing an amide bond, a vinyl monomer containing an amino group, and a vinyl monomer having a nitrogen-containing heterocyclic structure. More specifically, N-vinyl-2-pyrrolidone, N-vinylpyrrolidone, methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine , N-vinyl pyrazine, N-vinyl pyrrole, N-vinyl imidazole, N-vinyl oxazole, N-vinyl morpholine, N-vinyl caprolactam, N-vinyl lauryl lactam, etc. Cyclic nitrogen vinyl compounds having a cyclic structure; N-(meth)acryloylmorpholine, N-(meth)acryloylpiperazine, N-(meth)acryloylaziridine, N-(meth)acryloylazetidine, N-(meth)acrylic Complexity of N-(meth)acryloyl substitution such as roylpyrrolidine, N-(meth)acryloylpiperidine, N-(meth)acryloyl azepane, and N-(meth)acryloyl azocan Cyclic nitrogen vinyl compounds having a cyclic structure; Cyclic nitrogen vinyl compounds having a heterocyclic structure having a nitrogen atom such as N-cyclohexylmaleimide and N-phenylmaleimide and an ethylenically unsaturated bond in the ring; Unsubstituted or monoalkyl substituted (meth)acrylamides such as (meth)acrylamide, N-methyl(meth)acrylamide, N-isopropyl(meth)acrylamide, and N-t-butyl(meth)acrylamide; N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-dipropylacrylamide, N,N-diisopropyl(meth)acrylamide, N,N-di Dialkyls such as butyl (meth)acrylamide, N-ethyl-N-methyl (meth)acrylamide, N-methyl-N-propyl (meth)acrylamide, and N-methyl-N-isopropyl (meth)acrylamide Substituted (meth)acrylamide; N,N-dimethylaminomethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, N,N-dimethylaminoisopropyl (meth) Acrylate, N,N-dimethylaminobutyl (meth)acrylate, N,N-diethylaminomethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N-ethyl-N- Methylaminoethyl (meth)acrylate, N-methyl-N-propylaminoethyl (meth)acrylate, N-methyl-N-isopropylaminoethyl (meth)acrylate, N,N-dibutylaminoethyl (meth ) Acrylates, dialkylamino (meth)acrylates such as t-butylaminoethyl (meth)acrylate; N,N-dimethylaminopropyl (meth)acrylamide, N,N-diethylaminopropyl (meth)acrylamide, N,N-dipropylaminopropyl (meth)acrylamide, N,N-diisopropylaminopropyl (Meth)acrylamide, N-ethyl-N-methylaminopropyl (meth)acrylamide, N-methyl-N-propylaminopropyl (meth)acrylamide, N-methyl-N-isopropylaminopropyl (meth)acrylic N,N-dialkyl substituted aminopropyl (meth)acrylamide such as amide; N-vinyl carboxylic acid amides such as N-vinyl formamide, N-vinyl acetamide and N-vinyl-N-methyl acetamide; N-methoxymethyl (meth)acrylamide, N-ethoxyethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide, diacetone acrylamide, N,N-methylenebis (meth)acrylamide, etc. (Meth)acrylamides; Unsaturated carboxylic acid nitriles such as (meth)acrylonitrile; And the like.

(E-1) As the nitrogen-containing vinyl monomer, it is preferable not to contain a hydroxyl group, and it is more preferable not to contain a hydroxyl group and a carboxyl group. Examples of such monomers include the above-mentioned monomers, for example, acrylic monomers containing N,N-dialkyl substituted amino groups or N,N-dialkyl substituted amide groups; N-vinyl substituted lactams such as N-vinyl-2-pyrrolidone, N-vinyl caprolactam, and N-vinyl-2-piperidone; N-(meth)acryloyl substituted cyclic amines such as N-(meth)acryloylmorpholine and N-(meth)acryloylpyrrolidine are preferred.

In (E), (E-2) As an alkoxy group-containing alkyl (meth)acrylate monomer, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-propoxyethyl (Meth)acrylate, 2-isopropoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-methoxypropyl (meth)acrylate, 2-ethoxypropyl (meth)acrylate , 2-propoxypropyl (meth)acrylate, 2-isopropoxypropyl (meth)acrylate, 2-butoxypropyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-ethoxy Propyl (meth)acrylate, 3-propoxypropyl (meth)acrylate, 3-isopropoxypropyl (meth)acrylate, 3-butoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylic Rate, 4-ethoxybutyl (meth)acrylate, 4-propoxybutyl (meth)acrylate, 4-isopropoxybutyl (meth)acrylate, 4-butoxybutyl (meth)acrylate, and the like. have.

These alkoxy group-containing alkyl (meth)acrylate monomers have a structure in which the atoms of the alkyl group in the alkyl (meth)acrylate are substituted with alkoxy groups.

When the total amount of the acrylic polymer of the copolymer is 100 parts by weight, (E-1) a nitrogen-containing vinyl monomer not containing a hydroxyl group or (E-2) an alkoxy group-containing alkyl (meth)acrylate monomer is 0 to 20 parts by weight It is preferable to contain in proportion. (E-1) The nitrogen-containing vinyl monomer not containing a hydroxyl group and the (E-2) alkoxy group-containing alkyl (meth)acrylate monomer may be used alone or in combination of two or more. In the pressure-sensitive adhesive layer according to the present invention, the pressure-sensitive adhesive composition does not need to contain (E) a nitrogen-containing vinyl monomer containing no hydroxyl group or an alkoxy group-containing alkyl (meth)acrylate monomer.

(F) The bifunctional or higher isocyanate compound may be at least one or two or more selected from polyisocyanate compounds having at least two or more isocyanate (NCO) groups in one molecule. The polyisocyanate compound is classified into aliphatic isocyanate, aromatic isocyanate, acyclic isocyanate, alicyclic isocyanate, and the like, but any of them may be used. Specific examples of the polyisocyanate compound include aliphatic isocyanate compounds such as hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and trimethylhexamethylene diisocyanate (TMDI), diphenylmethane diisocyanate (MDI), And aromatic isocyanate compounds such as xylylene diisocyanate (XDI), hydrogenated xylylene diisocyanate (H6XDI), dimethyldiphenylenediisocyanate (TOID), and tolylene diisocyanate (TDI).

As a trifunctional or higher isocyanate compound, a trivalent or higher polyol (1), such as a biuret-modified isocyanate compound (a compound having two NCO groups in one molecule) or an isocyanurate-modified product, trimethylolpropane (TMP) or glycerin And adducts (polyol-modified products) with a compound having at least three or more OH groups in the molecule.

It is also possible to use only the (F-1) trifunctional isocyanate compound or (F-2) bifunctional isocyanate compound as the (F) bifunctional or higher isocyanate compound. Moreover, it is also possible to use together (F-1) trifunctional isocyanate compound and (F-2) bifunctional isocyanate compound.

In addition, examples of the (F-1) trifunctional isocyanate compound used in the present invention include isocyanurate forms of hexamethylene diisocyanate compounds, isocyanurate forms of isophorone diisocyanate compounds, and hexamethylene diisocyanate compounds. At least 1 selected from the group of (F-1-1) first aliphatic isocyanate compounds, consisting of a duct body, an adduct of an isophorone diisocyanate compound, a burette body of a hexamethylene diisocyanate compound, and a burette body of an isophorone diisocyanate compound. More than a species, the isocyanurate body of a tolylene diisocyanate compound, the isocyanurate body of a xylylene diisocyanate compound, the isocyanurate body of a hydrogenated xylylene diisocyanate compound, the adduct body of a tolylene diisocyanate compound, xyl It is preferable to contain at least 1 sort(s) selected from (F-1-2) 2nd aromatic type isocyanate compound group which consists of the adduct body of a relay diisocyanate compound and the adduct body of a hydrogenated xylylene diisocyanate compound. It is preferable to use (F-1-1) 1st aliphatic type isocyanate compound group and (F-1-2) 2nd aromatic type isocyanate compound group together. In the present invention, as the (F-1) trifunctional isocyanate compound (F-1-1) at least one or more selected from the first aliphatic isocyanate compound group, and (F-1-2) from the second aromatic isocyanate compound group By using at least one or more selected combinations, the balance of the adhesive force between the low-speed peeling region and the high-speed peeling region can be further improved.

In addition, the (F-1) trifunctional isocyanate compound is at least one or more selected from the (F-1-1) first aliphatic isocyanate compound group, and the (F-1-2) second aromatic isocyanate compound group. It includes at least one selected from among, and is preferably included in a total of 0.5 to 5.0 parts by weight with respect to 100 parts by weight of the copolymer. In addition, the mixing ratio of (F-1-1) at least one or more selected from the first aliphatic isocyanate compound group and (F-1-2) second aromatic or isocyanate compound group selected from (F- It is preferable that 1-1):(F-1-2) is in a range of 10%:90% to 90%:10% by weight.

Moreover, as a (F-2) bifunctional isocyanate compound used for this invention, it is a non-cyclic aliphatic isocyanate compound, and it is preferable that it is a compound produced|generated by reacting a diisocyanate compound and a diol compound.

For example, the diisocyanate compound is represented by the formula "O=C=NXN=C=O" (where X is a divalent group) and the diol compound is represented by the formula "HO-Y-OH" (where Y is a divalent group). At this time, examples of the compound produced by reacting the diisocyanate compound with the diol compound include a compound represented by the following formula (Z).

[Formula Z]

O=C=NX-(NH-CO-OYO-CO-NH-X) _n -N=C=O

Here, n is an integer of 0 or more. When n is 0, the formula Z represents "O=C=N-X-N=C=O". As the bifunctional acyclic aliphatic isocyanate compound, a compound in which n is 0 in the formula (Z) (a diisocyanate compound unreacted to the diol compound) may be included, but it is preferable to include a compound in which n is an integer of 1 or more as an essential component. The bifunctional acyclic aliphatic isocyanate compound may be a mixture composed of a plurality of compounds in which n in formula (Z) is different.

The diisocyanate compound represented by the formula "O=C=N-X-N=C=O" is an aliphatic diisocyanate. X is acyclic, and it is preferable that it is an aliphatic divalent group. The aliphatic diisocyanate is preferably one or two or more selected from the group consisting of tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate.

The diol compound represented by the formula "HO-Y-OH" is an aliphatic diol. Y is acyclic, and it is preferable that it is an aliphatic divalent group. As the diol compound, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-ethyl-2 -Among the group of compounds consisting of butyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol monohydroxypivalate, polyethylene glycol, and polypropylene glycol It is preferable to consist of 1 or 2 selected types.

It is preferable that the weight ratio (F-1/F-2) of the said (F-1) trifunctional isocyanate compound and (F-2) bifunctional isocyanate compound is 1-90. It is preferable that the (F) bifunctional or higher isocyanate compound is 0.1 to 10 parts by weight based on 100 parts by weight of the acrylic polymer.

(G) When the crosslinking accelerator of the metal chelate compound is a polyisocyanate compound, a substance that functions as a catalyst for the reaction (crosslinking reaction) between the copolymer and the crosslinking agent may be used, and amine compounds such as tertiary amines , Organometallic compounds such as metal chelate compounds, organotin compounds, organic lead compounds, and organic zinc compounds. In the present invention, a metal chelate compound is used as a crosslinking accelerator.

The metal chelate compound is a compound in which one or more polydentate ligands L are bonded to the central metal atom M. The metal chelate compound may or may not have one or more monodentate ligands X that bind to the metal atom M. For example, when the chemical formula of a metal chelate compound having one metal atom M is represented by M(L) _m (X) _n , m≥1 and n≥0. When m is 2 or more, m L may be the same ligand, or may be different ligands. When n is 2 or more, n Xs may be the same ligand or different ligands.

Examples of the metal atom M include Fe, Ni, Mn, Cr, V, Ti, Ru, Zn, Al, Zr, and Sn.

As the multidentate ligand L, β-ketoesters such as methyl acetoacetate, ethyl acetoacetate, octyl acetoacetate, oleyl acetoacetate, lauryl acetoacetate, and stearyl acetoacetate, and acetylacetone (aka 2,4-pentanedione) , Β-diketones such as 2,4-hexanedione and benzoyl acetone. These are ketoenol tautomeric compounds, and in the polydentate ligand L, enols (eg, acetylacetonate) in which the enol is deprotonated may be used.

As the monodentate ligand X, a halogen atom such as a chlorine atom or a bromine atom, pentanoyl group, hexanoyl group, 2-ethylhexanoyl group, octanoyl group, nonanoyl group, decanoyl group, dodecanoyl group, octadecanoyl group, etc. And alkoxy groups such as a group, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, and a butoxy group.

Specific examples of the metal chelate compound include tris(2,4-pentanedionate) iron(III), iron trisacetylacetonate, titanium trisacetylacetonate, ruthenium trisacetylacetonate, zinc bisacetylacetonate, and aluminum tris Acetylacetonate, zirconium tetrakisacetylacetonate, tris(2,4-hexanedionate) iron(III), bis(2,4-hexanedionate) zinc, tris(2,4-hexanedionate) titanium, And tris(2,4-hexanedionate)aluminum, tetrakis(2,4-hexanedionate)zirconium, and the like.

Examples of the organic tin compound include dialkyl tin oxide, a fatty acid salt of dialkyl tin, and a fatty acid salt of stannous tin. Conventionally, dibutyltin compounds have been used a lot, but recently, the toxicity problem of organotin compounds has been pointed out, and tributyltin (TBT) contained in dibutyltin compounds is also concerned as an endocrine disruptor. From the viewpoint of safety, long-chain alkyl tin compounds such as dioctyl tin compounds are preferred. As a specific organotin compound, dioctyl tin oxide, dioctyl tin dilaurate, etc. are mentioned. Sn compounds can also be used temporarily, but in the future, considering the tendency to use materials with higher safety, it is better to use metal chelate compounds such as Al, Ti, and Fe, which are more stable than Sn. desirable.

The metal chelate compound in the pressure-sensitive adhesive composition according to the present invention includes at least one selected from the group consisting of aluminum chelate compounds, titanium chelate compounds, iron chelate compounds, and tin chelate compounds (but not containing TBT). It is desirable to be.

(G) It is preferable that the crosslinking accelerator of the metal chelate compound is contained in an amount of 0.001 to 0.5 parts by weight based on 100 parts by weight of the copolymer.

(H) Ketoenol tautomeric compounds include β-ketoesters such as methyl acetoacetate, ethyl acetoacetate, octyl acetoacetate, oleyl acetoacetate, lauryl acetoacetate, and stearyl acetoacetate, acetylacetone, 2 And β-diketones such as ,4-hexanedione and benzoyl acetone. In the pressure-sensitive adhesive composition containing a polyisocyanate compound as a cross-linking agent, by blocking the isocyanate group possessed by the cross-linking agent, excessive viscosity increase and gelation of the pressure-sensitive adhesive composition after mixing of the cross-linking agent can be suppressed, and the pot life of the pressure-sensitive adhesive composition can be extended. .

(H) The ketoenol tautomeric compound is preferably included in an amount of 0.1 to 200 parts by weight based on 100 parts by weight of the copolymer.

(H) ketoenol tautomeric compounds (G) in terms of having an effect of inhibiting crosslinking as opposed to the crosslinking accelerator of the metal chelate compound, (G) (H) ketoenol tautomerizing to the crosslinking accelerator of the metal chelate compound It is preferable to set the ratio of isomer compounds appropriately. In order to increase the pot life of the pressure-sensitive adhesive composition and improve storage stability, the weight ratio of (G):(H) is preferably in the range of 1:1 to 1:300, more preferably 1:30 to 1:300. And most preferably 1:80 to 1:300.

(I) As an antistatic agent, the antistatic agent contained in an adhesive composition and the antistatic agent copolymerized in the said copolymer are mentioned. It is preferable that the antistatic agent (I) is contained in an amount of 0.05 to 5.0 parts by weight based on 100 parts by weight of the copolymer.

It is preferable that the antistatic agent (I) is an ionic compound having a melting point of (I-1) 25 to 50°C and/or an ionic compound containing (I-2) acryloyl group.

In the present invention, (I) as an antistatic agent, (I-1) an ionic compound having a melting point of 25 to 50°C is added to the copolymer, and/or (I-2) acryloyl group-containing ionic compound is copolymerized in the copolymer. do. Since the antistatic agent (I) has a low melting point and further has a long chain alkyl group, it is presumed that the affinity with the acrylic copolymer is high.

(I-1) As an ionic compound having a melting point of 25 to 50°C, it is an ionic compound having cations and anions, the cations being pyridinium cation, imidazolium cation, pyrimidinium cation, pyrazolium cation -one, pyrrolidin-pyridinium cation, an ammonium cation also including on a nitrogen onium cation or a phosphonium cation, sulfonium cation or the like on the anion is hexafluorophosphate phosphate (PF ₆ ^-), thiocyanate (SCN ^-), alkyl benzene sulfonate ^{_{(RC 6 H 4 SO 3 -}} ), perchlorate (ClO ₄ ^{-) -} can be an inorganic anion or an organic phosphorus compound, such as, borate tetrafluoride (BF _4). It is preferable that it is a solid at room temperature (for example, 25°C), and a melting point of 25 to 50°C can be obtained by selecting the chain length of the alkyl group, the position and number of substituents, and the like. The cation is preferably a quaternary nitrogen onium cation, a quaternary pyridinium cation such as 1-alkylpyridinium (the carbon atom in the 2-6 position may have a substituent or may be unsubstituted) or 1 Quaternary ammonium cations such as quaternary imidazolium cations and tetraalkylammonium, such as ,3-dialkylimidazolium (carbon atoms at positions 2, 4, and 5 may have substituents or may be unsubstituted). And the like.

(I-1) The ionic compound having a melting point of 25 to 50°C is preferably included in an amount of 0.1 to 5.0 parts by weight based on 100 parts by weight of the copolymer.

(I-2) An acryloyl group-containing ionic compound is an ionic compound having cations and anions, and the cation is (meth)acryloyloxyalkyltrialkylammonium [R ₃ N ⁺ -C _n H _2n -OCOCQ = CH _2, stage, Q = H or CH _3, R = alkyl] such as (meth) and group-containing cation with acrylic, anion is hexafluorophosphate phosphate (PF ₆ ^-), thiocyanate (SCN ^-), an organic sulfonic acid salts (RSO ₃ ^-), perchlorate (ClO ₄ ^-) may be an inorganic anion or an organic phosphorus compound, such as, borate tetrafluoride (BF ₄ ^{- -),} F-containing already deuyeom (R ^F ₂ N). 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 (ethanesulfonyl pentafluorophenyl) already deuyeom _{[(C 2 F 5 SO 2)} 2 N - ] there are bis sulfonyl imide salts such as be mentioned.

(I-2) It is preferable that the acryloyl group-containing ionic compound is copolymerized in an amount of 0.1 to 5.0% by weight in the copolymer.

(I) Although it is not particularly limited as a specific example of the antistatic agent, (I-1) As a specific example of the ionic compound having a melting point of 25 to 50°C, 1-octylpyridinium hexafluorophosphate, 1-nonyl Pyridinium hexafluorophosphate, 2-methyl-1-dodecylpyridinium hexafluorophosphate, 1-octylpyridinium dodecylbenzenesulfonate, 1-dodecylpyridinium thiocyanate, 1-dodecylpyridinium dodecylbenzene Sulfonate, 4-methyl-1-octylpyridinium hexafluorophosphate, and the like. Moreover, as a specific example of the (I-2) acryloyl group-containing ionic compound, dimethylaminomethyl (meth)acrylate hexafluorophosphate methyl salt [(CH ₃ ) ₃ N ⁺ CH ₂ OCOCQ=CH ₂ ·PF ₆ ^- , Provided that Q=H or CH ₃ ], dimethylaminoethyl (meth)acrylate bis(trifluoromethanesulfonyl)imidemethyl salt [(CH ₃ ) ₃ N ⁺ (CH ₂ ) ₂ OCOCQ=CH _{2 · (CF 3 SO 2) 2} N -, stage, Q = H or CH _3], dimethylaminoethyl methacrylate-bis (sulfonyl fluorophenyl) salt imide methyl [(CH _{3) 3} N ⁺ CH ₂ OCOCQ = _{CH 2 · (FSO 2) 2} N -, however, and the like can be Q = H or CH _3].

The pressure-sensitive adhesive composition may optionally contain (J) a polyether-modified siloxane compound. (J) The polyether-modified siloxane compound is a siloxane compound having a polyether group, and in addition to the conventional siloxane unit [-SiR ¹ ₂ -O-], a siloxane unit having a polyether group [-SiR ¹ (R ² O(R ³ O ) _n R ⁴ )-O-]. Here, R ¹ is one or two or more alkyl groups or aryl groups, R ² and R ³ are one or two or more alkylene groups, R ⁴ is one or two or more alkyl groups or acyl groups (terminal groups). Shows. Examples of the polyether group include polyoxyalkylene groups such as polyoxyethylene groups [(C ₂ H ₄ O) _n ] and polyoxypropylene groups [(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 15. Moreover, it is preferable that (J) polyether modified siloxane compound is contained in 0.01-1.0 weight part with respect to 100 weight part of copolymer. More preferably, it is 0.1 to 0.5 parts by weight.

The HLB is, for example, a hydrophilic lipophilic balance (hydrophilic lipophilic ratio) specified in JIS K3211 (a surfactant term).

(J) 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 silicon hydride group by a hydrosilylation reaction. Specifically, dimethylsiloxane methyl (polyoxyethylene) siloxane copolymer, dimethylsiloxane methyl (polyoxyethylene) siloxane methyl (polyoxypropylene) siloxane copolymer, dimethylsiloxane methyl (polyoxypropylene) siloxane polymer, etc. Can be heard.

(J) By blending the polyether-modified siloxane compound with the pressure-sensitive adhesive composition, the pressure-sensitive adhesive and rework performance of the pressure-sensitive adhesive can be improved. When the pressure-sensitive adhesive composition does not contain a polyether-modified siloxane compound, it becomes more expensive.

In addition, copolymerizable (meth)acrylic monomers containing alkylene oxides as other components, (meth)acrylamide monomers, dialkyl substituted acrylamide monomers, surfactants, curing accelerators, plasticizers, fillers, curing retarders, processing aids Known additives, such as anti-aging agents and antioxidants, can be appropriately blended. These are used alone or in combination of two or more.

The copolymer of the subject used for the pressure-sensitive adhesive composition of the present invention is (A) at least one of (meth)acrylic acid ester monomers having C4 to C18 alkyl groups, and (B) a copolymerizable group containing a hydroxyl group as a copolymerizable monomer group. A monomer, (C) a copolymerizable monomer containing a carboxyl group, (D) a polyalkylene glycol mono(meth)acrylic acid ester monomer, and (E) a nitrogen-containing vinyl monomer containing no hydroxyl group or an alkyl containing an alkoxy group (meth) ) Can be synthesized by copolymerizing at least one selected from the group of copolymerizable monomers composed of acrylate monomers. The polymerization method of the copolymer is not particularly limited, and suitable polymerization methods such as solution polymerization and emulsion polymerization can be used.

(I) When an ionic compound containing (I-2) acryloyl group is used as an antistatic agent, the main copolymer used in the pressure-sensitive adhesive composition of the present invention is (A) (meth) having an alkyl group having C4 to C18 carbon atoms. At least 1 type of acrylic acid ester monomer, as a copolymerizable monomer group, (B) a copolymerizable monomer containing a hydroxyl group, (C) a copolymerizable monomer containing a carboxyl group, and (D) polyalkylene glycol mono(meth)acrylic acid At least one member selected from the group of copolymerizable monomers consisting of an ester monomer and (E) a nitrogen-containing vinyl monomer not containing a hydroxyl group or an alkoxy group-containing alkyl (meth)acrylate monomer, and (I-2) acryloyl group-containing ion It can be synthesized by copolymerizing the sex compound.

The pressure-sensitive adhesive composition of the present invention comprises (F) a bifunctional or higher isocyanate compound, (G) a crosslinking accelerator of a metal chelate compound, (H) a ketoenol tautomer compound, (I) an antistatic agent, (J) poly It can be produced by compounding an ether-modified siloxane compound, and optionally any additives as appropriate. In addition, when the (I-2) acryloyl group-containing ionic compound is polymerized in the main copolymer, (I) an antistatic agent may or may not be added to the copolymer.

It is preferable that the said copolymer is an acrylic polymer, and it is preferable to contain 50-100 weight% of acrylic monomers, such as (meth)acrylic acid ester monomer, (meth)acrylic acid, and (meth)acrylamide.

Moreover, it is preferable that the acid value of acrylic polymer is 0.01-8.0. Thereby, it is possible to improve the contamination and to prevent the generation of adhesive residues.

Here, the "acid value" is one of the indicators showing the content of the acid, and is represented by the number of mg of potassium hydroxide required to neutralize 1 g of a polymer containing a carboxyl group.

The pressure-sensitive adhesive layer formed by crosslinking the pressure-sensitive adhesive composition has a low-speed peeling rate of 0.3 m/min to 0.05 to 0.1 N/25 mm, and a high-speed peeling speed of 30 m/min to preferably have an adhesive strength of 1.0 N/25 mm or less. . Thereby, the performance in which the adhesive force changes little even by the peeling speed can be obtained, and it is possible to peel quickly even by high-speed peeling. Moreover, in order to re-attach, even when peeling a surface protection film once, excessive force is not required and it is easy to peel from an adherend.

It is preferable that the surface resistivity of the pressure-sensitive adhesive layer formed by crosslinking the pressure-sensitive adhesive composition is 9.0×10 ⁺¹⁰ Ω/□ or less, and the peeling voltage is ±0 to 0.5 MPa. In addition, in the present invention, "±0 to 0.5 Pa" means 0 to -0.5 Pa and 0 to +0.5 Pa, that is, -0.5 to +0.5 Pa. When the surface resistivity is large, the ability to escape static electricity generated by charging at the time of peeling decreases, so by sufficiently reducing the surface resistivity, the peeling voltage generated by the static electricity generated when the adherend peels off the pressure-sensitive adhesive layer is reduced. As a result, it is possible to suppress the influence on the electrical control circuit and the like of the adherend.

It is preferable that the gel fraction of the pressure-sensitive adhesive layer (cross-linked pressure-sensitive adhesive) formed by crosslinking the pressure-sensitive adhesive composition of the present invention is 95 to 100%. As a result of the high gel fraction, the adhesive strength is not excessive at a low-speed peeling rate, and the elution of unpolymerized monomers or oligomers from the copolymer is reduced, improving reworkability and durability at high temperatures and high humidity, thereby avoiding Contamination of the complex can be suppressed.

The adhesive film of the present invention is formed by forming an adhesive layer formed by crosslinking the adhesive composition of the present invention on one side or both sides of a resin film. Moreover, the surface protection film of this invention is a surface protection film formed by forming the adhesive layer formed by crosslinking the adhesive composition of this invention on one side of a resin film. The pressure-sensitive adhesive composition of the present invention has excellent anti-static performance because each component of (A) to (J) is balanced, excellent adhesion at low-speed peeling speed and high-speed peeling speed, and also , Durability performance and rework performance (after the adhesive layer is overlaid on the surface protective film with a ballpoint pen, there is no contamination transfer to the adherend) is also excellent. For this reason, it can use suitably as a use of the surface protection film of a polarizing plate.

As a base film of an adhesive layer or a peeling film (separator) which protects an adhesive surface, resin films, such as a polyester film, etc. can be used.

The base film may be subjected to an antistatic treatment by antifouling treatment with a silicone-based or fluorine-based release agent or coating agent, silica fine particles, or an antistatic agent, or the like, on a surface opposite to the side on which the pressure-sensitive adhesive layer of the resin film is formed.

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

Example

Hereinafter, the present invention will be described in detail by examples.

<Preparation of acrylic copolymer>

[Example 1]

Nitrogen gas was introduced into the reactor equipped with a stirrer, a thermometer, a reflux cooler, and a nitrogen introduction tube to replace air in the reaction device with nitrogen gas. Thereafter, 100 parts by weight of 2-ethylhexyl acrylate, 3.0 parts by weight of 8-hydroxyoctyl acrylate, and polypropylene glycol monoacrylate (average repetition number of alkylene oxides constituting the polyalkylene glycol chain n) = 12) 60 parts by weight of a solvent (ethyl acetate) was added together with 10 parts by weight. Thereafter, 0.1 part by weight of azobisisobutyronitrile was added dropwise over 2 hours as a polymerization initiator, and reacted at 65°C for 6 hours to obtain an acrylic copolymer solution (1) used in Example 1 with a weight average molecular weight of 500,000. Got. A part of the acrylic copolymer was collected and used as a measurement sample of the acid value described later.

[Examples 2 to 6, Reference Examples 1 to 3 and Comparative Examples 1 to 4]

The composition of the monomer was the same as that of the acrylic copolymer solution (1) used in Example 1, except that the compositions described in Tables 1 (A) to (E) and (I-2) were used, respectively. 6, the acrylic copolymer solutions used for Reference Examples 1 to 3 and Comparative Examples 1 to 4 were obtained.

<Production of adhesive composition and surface protection film>

[Example 1]

With respect to the acrylic copolymer solution (1) of Example 1 prepared as described above, 1-octylpyridinium hexafluorophosphate 1.5 parts by weight, polyether-modified siloxane compound (HLB=7) 0.05 parts by weight, acetylacetone 8.5 parts by weight After addition and stirring, 2.0 parts by weight of coronate HX (isocyanurate of hexamethylene diisocyanate compound) and 0.1 parts by weight of titanium trisacetylacetonate were added and stirred and mixed to obtain the pressure-sensitive adhesive composition of Example 1. After applying this pressure-sensitive adhesive composition on a release film made of a silicone resin-coated polyethylene terephthalate (PET) film, the solvent was removed by drying at 90° C. to obtain a pressure-sensitive adhesive sheet having a thickness of the pressure-sensitive adhesive layer of 25 μm.

After that, the adhesive sheet was transferred to the surface opposite to the antistatic and antifouling treated surface of the polyethylene terephthalate (PET) film, which was treated with antistatic and antifouling treatment on one side. The surface protection film of Example 1 which has a laminated structure of an adhesive layer/peel film (silicone resin coated PET film) was obtained.

[Examples 2 to 6, Reference Examples 1 to 3 and Comparative Examples 1 to 4]

Examples 2 to 6, Reference Examples 1 to 3, and Comparative Example 1 were used in the same manner as in the surface protection film of Example 1, except that the composition of the additives was as described in Tables (F) to (J) in Table 2, respectively. A surface protective film of -4 was obtained.

In Table 1 and Table 2, the whole table showing the mixing ratio of each component was divided into two, and the numerical value of the weight part obtained by calculating the total of 100 parts by weight of the entire group (A) is shown in parentheses. In addition, the compound name of the abbreviation of each component used in Table 1 and Table 2 is shown in Table 3 and Table 4. Coronate (registered trademark) HX, HL and L are trade names of Nihon Polyurethane Industry Co., Ltd., and Takenate (registered trademark) D-140N, D-127N, D-110N, and D-120N are trade names of Mitsui Chemicals Co., Ltd. And Death Module (registered trademark) N3400 is a trade name of Sumika Bayer Urethane.

In Table 1, of the (I) antistatic agent, the (I-2) acryloyl group-containing ionic compound copolymerized in the copolymer was described in a separate column from the (I) antistatic agent added after polymerization.

<Synthesis of a bifunctional isocyanate compound>

The difunctional isocyanate compounds of Synthesis Examples 1-3 were synthesized by the following method. As shown in Tables 5 and 6, the diisocyanate and the diol compound were mixed at a molar ratio: NCO/OH=16, reacted at 120° C. for 3 hours, and then unreacted under reduced pressure using a thin film evaporator. The diisocyanate of was removed, and the desired difunctional isocyanate compound was obtained.

<Test method and evaluation>

The peeling film (silicone resin coated PET film) after aging the surface protection films in Examples 1 to 6, Reference Examples 1 to 3 and Comparative Examples 1 to 4 under an atmosphere of 23° C. and 50% RH for 7 days. Was peeled off and the pressure-sensitive adhesive layer was expressed as a measurement sample of surface resistivity.

In addition, the surface protection film expressing this pressure-sensitive adhesive layer was pasted to the surface of the polarizing plate attached to the liquid crystal cell via the pressure-sensitive adhesive layer, left to stand for 1 day, and autoclaved at 50°C, 5 atmospheres and 20 minutes, and again at room temperature. What was left for 12 hours was used as a measurement sample for adhesion, peeling voltage, reworkability and durability.

<adhesive power>

The measurement sample obtained above (a 25 mm-wide surface protective film is affixed to the surface of the polarizing plate) using a tensile tester in the direction of 180°, a low-speed peeling speed (0.3 m/min) and a high-speed peeling speed (30 m/min) The peel strength measured by peeling in was used as the adhesive force.

<Surface resistivity>

After aging, before sticking to the polarizing plate, the release film (silicone resin coated PET film) is peeled off to expose the pressure-sensitive adhesive layer, and the resistive layer is measured using a resistivity meter High-Resta UP-HT450 (manufactured by Mitsubishi Chemical Analytics) Surface resistivity was measured.

<Peeling off voltage>

When the measurement sample obtained above is peeled 180° at a tensile speed of 30 m/min, the voltage (high voltage) generated by charging of the polarizing plate is measured using high-accuracy electrostatic sensors SK-035 and SK-200 (manufactured by Keyence Co., Ltd.). Then, the maximum value of the measured value was taken as the peeling large voltage.

<rework property>

After overwriting the surface protective film of the measurement sample obtained above with a ball pen (500 g load, 3 reciprocations), the surface protective film was peeled from the polarizing plate to observe the surface of the polarizing plate, and it was confirmed that there was no contamination migration on the polarizing plate. The evaluation target criterion is ``○'' when there is no contamination transition on the polarizing plate, △ when the pollution transition is confirmed on at least a part along the trajectory overwritten with a ballpoint pen, and contamination transition is confirmed along the trajectory overwritten with a ballpoint pen, and the adhesive surface It was evaluated as "x" when the release of the adhesive was also confirmed from.

<port life>

The viscosity η ₀ (initial viscosity) of the pressure-sensitive adhesive composition immediately after blending the additives (F) to (J) is measured, and the viscosity of the pressure-sensitive adhesive composition after leaving the pressure-sensitive adhesive composition in a closed state at 23° C. for 8 hours again η ₁ ( The viscosity after 8 hours) was measured. As an index of pot life, a value of η ₁ when η ₀ was 1.0, that is, a ratio of η ₁ /η ₀ was obtained. The evaluation target criterion is evaluated as "○" when the viscosity after 8 hours is less than 1.25 times the initial viscosity, "△" when it is 1.25 times or more and less than 1.50 times, or "X" when it is gelled by leaving it at least 1.50 times or 8 hours. Did.

<durability>

The measurement sample obtained above was left at room temperature in an atmosphere of 60° C. and 90% RH for 250 hours, then taken out to room temperature, and then left again for 12 hours, and the adhesive force was measured to confirm that there was no obvious increase compared to the initial adhesive force. The evaluation target criteria evaluated "○" when the adhesive strength after the test was 1.5 times or less of the initial adhesive strength, and "X" when it exceeded 1.5 times.

Table 7 shows the evaluation results. Incidentally, the surface resistivity was expressed by a method in which “m×10 ^{+ n} ”is “mE+n” (where m is an arbitrary real value and n is a positive integer).

The surface protective films of Examples 1 to 6 and Reference Examples 1 to 3 had an adhesive strength at a low-speed peeling rate of 0.3 m/min of 0.05 to 0.1 N/25 mm, and an adhesive strength at a high-speed peeling speed of 30 m/min of 1.0 N/25. ㎜ or less, the surface resistivity is 9.0 × 10 ^{+ 10} Ω / □ or less, the peeling voltage is ±0 ~ 0.5 ,, after the adhesive layer is overlaid on the surface protective film with a ballpoint pen, there is no contamination migration to the adherend , The pot life was long, and the durability when left for 250 hours in an atmosphere of 60°C and 90%RH was also excellent.

That is, it has antistatic performance, and at a low-speed peeling speed and a high-speed peeling speed, the balance of adhesive strength is excellent, the pot life is long, and durability and reworkability are also excellent.

Further, according to the surface protection films of Examples 1 to 6, since the organotin compound is not included in the pressure-sensitive adhesive composition, safety is high.

The surface protective film of Comparative Example 1 is because it does not contain an isocyanate compound having a bifunctional or higher function as a crosslinking agent (F), the adhesive strength at a low-speed peeling rate of 0.3 m/min and a high-speed peeling speed of 30 m/min is too large, and the surface resistivity And the peeling high voltage was high, and the rework property and durability were poor.

In the surface protection film of Comparative Example 2, (G) the ratio of the (H) ketoenol tautomer to the crosslinking accelerator of the metal chelate compound is small, and (J) the HLB value of the polyether-modified siloxane compound is excessive. The perceived, peeling high voltage was high, the pot life was slightly short, and the durability was poor.

Since the surface protection film of Comparative Example 3 uses a crosslinking accelerator of an organotin compound instead of a crosslinking accelerator of (G) a metal chelate compound, the ratio of (H) ketoenol tautomeric compound to this crosslinking accelerator is smaller. , Pot life was too short and crosslinking proceeded before application, so coating could not be performed.

The surface protection film of Comparative Example 4 is because (G) the crosslinking accelerator of the metal chelate compound and (H) the ketoenol tautomeric compound are not all included, and (J) the polyether-modified siloxane compound is not included. , The adhesive strength at a high-speed peeling speed of 30 m/min was too large, the pot life was short, and the durability was poor.

As described above, the surface protective films of Comparative Examples 1 to 4 have antistatic performance, and have excellent balance of adhesion in low-speed peeling speed and high-speed peeling speed, and also have a long pot life, excellent durability and reworkability. It could not satisfy all the required performances at the same time.

Claims (4)

As the surface protection film which the adhesive layer which bridge|crosslinked the adhesive composition containing an acrylic polymer, (I) antistatic agent, and (F) bifunctional or more isocyanate compound as a crosslinking agent is formed on one surface of a resin film,
As said acrylic polymer, (A) At least 1 sort(s) of (meth)acrylic acid ester monomer which C4-C18 of an alkyl group has carbon number, (B) At least 1 sorts of copolymerizable monomer containing a hydroxyl group, and a copolymerizable monomer group ( C) a copolymerizable monomer containing a carboxyl group, (D) a polyalkylene glycol mono(meth)acrylic acid ester monomer, and (E) a nitrogen-containing vinyl monomer containing no hydroxyl group or an alkyl containing an alkoxy group containing no hydroxyl group ( It consists of an acrylic polymer of the copolymer which copolymerized at least 1 sort(s) selected from the copolymerizable monomer group which consists of meth)acrylate monomers,
The (D) polyalkylene glycol mono (meth) acrylic acid ester monomer is polyalkylene glycol mono (meth) acrylate, methoxy polyalkylene glycol (meth) acrylate, ethoxy polyalkylene glycol (meth) acrylate At least one selected from
The pressure-sensitive adhesive composition further contains (G) a crosslinking accelerator for the metal chelate compound, (H) a ketoenol tautomer compound, and (J) a polyether-modified siloxane compound having an HLB value of 7 to 15,
With respect to 100 parts by weight of the total amount of the acrylic polymer, 0.001 to 0.5 parts by weight of the crosslinking accelerator of the (G) metal chelate compound and 7.5 to 200 parts by weight of the (H) ketoenol tautomeric compound are included. G): The surface protective film characterized in that the weight ratio of (H) is 1:80 to 1:300. According to claim 1,
With respect to 100 parts by weight of the total of the acrylic polymer,
The acrylic polymer
50 to 95 parts by weight of the (meth)acrylic acid ester monomer having C4 to C18 carbon atoms in the alkyl group (A),
0.1 to 10 parts by weight of the copolymerizable monomer (B) containing a hydroxyl group,
0 to 1.0 parts by weight of the copolymerizable monomer (C) containing a carboxyl group,
0 to 50 parts by weight of the (D) polyalkylene glycol mono (meth) acrylic acid ester monomer,
The (E) contains 0 to 20 parts by weight of a nitrogen-containing vinyl monomer containing no hydroxyl group or an alkoxy group-containing alkyl (meth)acrylate monomer containing no hydroxyl group,
The pressure-sensitive adhesive composition
As the cross-linking agent (F), 0.1 to 10 parts by weight of a bifunctional or higher isocyanate compound,
The (I) an ionic compound having an melting point of 25 to 50°C included in 0.1 to 5.0 parts by weight in the pressure-sensitive adhesive composition as an antistatic agent, and/or an ionic compound containing an acryloyl group copolymerized in an amount of 0.1 to 5.0 parts by weight in the copolymer. 0.1 to 5.0 parts by weight in total,
(J) The surface protective film, characterized in that it contains 0.01 to 1.0 parts by weight of the polyether-modified siloxane compound having an HLB value of 7 to 15. The method of claim 1 or 2,
The (B) copolymerizable monomer containing a hydroxyl group, 8-hydroxyoctyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxy At least one selected from the group of compounds consisting of ethyl (meth)acrylate, N-hydroxy (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, and N-hydroxyethyl (meth)acrylamide,
(C) The copolymerizable monomer containing a carboxyl group includes (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, 2-(meth)acryloyloxyethylhexahydrophthalic acid, 2-( Meta)acryloyloxypropylhexahydrophthalic acid, 2-(meth)acryloyloxyethylphthalic acid, 2-(meth)acryloyloxyethylsuccinic acid, 2-(meth)acryloyloxyethylmaleic acid, carboxypoly A surface protection film, characterized in that at least one selected from the group consisting of caprolactone mono(meth)acrylate and 2-(meth)acryloyloxyethyltetrahydrophthalic acid. The method of claim 1 or 2,
A surface protection film used as a use for a surface protection film of a polarizing plate.