TWI465539B - Adhesive Composition And Surface-Protective Adhesive Film - Google Patents

Description

Adhesive composition and surface protective film

The present invention relates to a surface protective film used in the manufacturing process of a liquid crystal display. More specifically, the present invention relates to a surface protective film for protecting a surface of an optical member such as a polarizing plate or a phase difference plate by being adhered to a surface of an optical member such as a polarizing plate or a phase difference plate constituting a liquid crystal display. A composition of the composition, and a surface protective film using the same.

In the manufacturing process of an optical member such as a polarizing plate or a phase difference plate which is a member constituting a liquid crystal display, the surface protective film is adhered to temporarily protect the surface of the optical member. Such a surface protective film is used only in the process of manufacturing an optical component, and when the optical component is inserted into the liquid crystal display, it is peeled off from the optical component and removed. Since such a surface protective film for protecting the surface of an optical member is used only in a manufacturing process, it is also generally referred to as a "process film".

For such a surface protective film used in the process of manufacturing an optical component, an adhesive layer is formed on one surface of an optically transparent polyethylene terephthalate (PET) resin film, but it is sticky. A release film that has been subjected to a release treatment is attached to the coating layer to protect the adhesive layer until it is bonded to the optical member.

In addition, in an optical member such as a polarizing plate or a phase difference plate, the display capability, color tone, and contrast accompanying the liquid crystal display panel are performed in a state in which the surface protective film is bonded. The product inspection of optical evaluation such as the incorporation of impurities is required. As a performance requirement for the surface protective film, it is required that the adhesive layer does not contain bubbles or impurities.

In addition, when a surface protective film is bonded to an optical member such as a polarizing plate or a phase difference plate, there is a case where the surface protective film is temporarily peeled off after temporarily peeling off the surface protective film for various reasons, and at this time, it is required to be easily adhered. Peeling (reworkability) on the optical component of the body.

Further, when the surface protective film is peeled off from an optical member such as a final polarizing plate or a phase difference plate, it is required to be able to be quickly peeled off. That is, it is required that the adhesion force is small due to the change in the peeling speed, so that it can be peeled off quickly even in the case of high-speed peeling.

As described above, in recent years, from the viewpoint of easy handling when using a surface protective film, it is required that the adhesive layer constituting the surface protective film has the following properties: (1) A balance of adhesion is obtained at a low peeling speed and a high peeling speed. (2) prevention of the occurrence of adhesive residue; and (3) rework performance.

However, even if the performance requirements for the adhesive layer constituting the surface protective film can be satisfied, that is, even if the individual performance requirements in the above (1) to (3) can be respectively satisfied, the adhesion of the surface protective film is required to be satisfied at the same time. The agent layer has all the performance requirements of (1) to (3), which is a very difficult problem.

For example, regarding (1) the balance of the adhesive force at the low peeling speed and the high peeling speed, and (2) the prevention of the occurrence of the adhesive residue, the following suggestions are known.

a copolymer of a (meth)acrylic acid alkyl ester having an alkyl group having 7 or less carbon atoms and a carboxyl group-containing copolymerizable compound as a main component, and which is crosslinked by a crosslinking agent. In the acrylic adhesive layer, when it is adhered for a long period of time, the adhesive moves to the side of the adherend and adheres to the adherend, and the adhesion to the adherend is increased with time. The problem. In order to avoid this question A method of providing an adhesive layer using an alkyl (meth)acrylate having an alkyl group having 8 to 10 carbon atoms and having an alcoholic hydroxyl group is known. An adhesive layer obtained by crosslinking a copolymer of a copolymerizable compound and crosslinking it with a crosslinking agent (Patent Document 1).

Further, a proposal has been made in which an adhesive layer is provided by mixing a small amount of an alkyl (meth) acrylate and a carboxyl group in the same copolymer as described above. A copolymer of a copolymerizable compound and an adhesive layer obtained by crosslinking it with a crosslinking agent. However, when it is used for the surface protection of a plastic plate or the like having a low surface tension and a smooth surface, there is a problem of peeling phenomenon such as separation due to heating during processing or storage, and high-speed peeling in the field of manual operation. The problem of poor removability.

In order to solve these problems, an adhesive composition is proposed which is characterized in that a) an alkyl (meth)acrylate having an alkyl group having 8 to 10 carbon atoms as a main component To 100 parts by weight of the alkyl (meth) acrylate, b) 1 to 15 parts by weight of a carboxyl group-containing copolymerizable compound, and c) 3 to 100 parts by weight of an aliphatic carboxylic acid having 1 to 5 carbon atoms An adhesive composition obtained by mixing a copolymer of a monomer mixture with a vinyl ester and blending a crosslinking agent having a carboxyl group equivalent or more of the above b) component into the copolymer (Patent Document 2).

In the adhesive composition described in Patent Document 2, peeling phenomenon such as separation does not occur during processing or storage, and the adhesion strength is small with time, and the removability is excellent, and even for long-term storage, In particular, when it is stored for a long period of time in a high-temperature environment, it can be re-peeled with a small force. At this time, no adhesive remains on the adherend, and re-peeling can be performed with a small force even when high-speed peeling is performed. .

Further, regarding (3) reworkability, for example, an adhesive composition is proposed, The pressure-sensitive adhesive composition is obtained by blending 0.0001 to 10 parts by weight of a curing agent of an isocyanate compound and a specific phthalate oligomer with respect to 100 parts by weight of the acrylic resin (Patent Document 3).

Patent Document 3 describes that an alkyl acrylate having an alkyl group having a carbon number of from 2 to 12 or an alkyl methacrylate having an alkyl group having a carbon number of from 4 to 12 is used as a main single. The body component may contain, for example, a monomer component containing another functional group such as a carboxyl group-containing monomer. In general, it is preferable to contain 50% by weight or more of the above-mentioned main monomer, and it is desirable that the content of the monomer component containing a functional group is 0.001 to 50% by weight, preferably 0.001 to 25% by weight, and more preferably 0.01 to 25% by weight. The adhesive composition described in Patent Document 3 has a small change in the cohesive force and the adhesive force over a high temperature or a high temperature and high humidity, and exhibits an excellent effect on the adhesion of the curved surface. Reworkability.

In general, when the pressure-sensitive adhesive layer is soft, the adhesive tends to remain and the reworkability is easily lowered. That is, it is difficult to peel off after the wrong bonding, and it is difficult to re-stick. From this point of view, in order to impart reworkability, it is necessary to crosslink a monomer having a functional group such as a carboxyl group to the main component so that the adhesive layer has a certain hardness.

Prior art literature Patent literature

Patent Document 1: Japanese Patent Laid-Open Publication No. SHO 63-225677

Patent Document 2: Japanese Patent Laid-Open No. Hei 11-256111

Patent Document 3: Japanese Patent Publication No. 8-199130

In the prior art, as a performance requirement for an adhesive layer constituting a surface protective film, It has been demanded to have a balance of adhesion at low peeling speed and high peeling speed, and reworkability and the like. However, even if the performance requirements can be individually satisfied, it is impossible to satisfy all the performance requirements required for the adhesive layer as the surface protective film.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an adhesive composition and a surface which are excellent in balance of adhesion at a low peeling speed and a high peeling speed, and which are excellent in durability and reworkability. Protective film.

In order to solve the above problems, the present invention provides an adhesive composition comprising an acrylic polymer comprising a copolymer having an acrylic polymer containing (A) an alkyl group having a carbon number of C4 to C10. (meth) acrylate monomer, (B) hydroxyl group-containing copolymerizable monomer, (C) carboxyl group-containing copolymerizable monomer, (D) polyalkylene glycol mono (meth) acrylate single And (E) at least one of a hydroxyl group-free nitrogen-containing vinyl monomer or an alkoxy group-containing alkyl (meth) acrylate monomer, and further containing (F) a trifunctional or higher isocyanate compound And (G) a crosslinking retarder, (H) a crosslinking catalyst, and (I) a polyether modified siloxane compound, wherein the acrylic polymer has an acid value of 0.01 to 8.0, and the (F) trifunctional or higher The isocyanate compound includes at least one selected from the group consisting of (F-1) a first aliphatic isocyanate compound group and at least one selected from the group consisting of (F-2) a second aromatic isocyanate compound.

Among the above-mentioned (F) trifunctional or higher isocyanate compounds, the (F-1) first aliphatic isocyanate compound group is preferably an isocyanurate or an isophorone diisocyanate compound of a hexamethylene diisocyanate compound. Addition of isocyanurate, hexamethylene diisocyanate compound, adduct of isophorone diisocyanate compound, biuret of hexamethylene diisocyanate compound, isophorone diisocyanate The biuret composition of the compound; preferably the (F-2) second aromatic isocyanate compound group isocyanurate of toluene diisocyanate compound, isocyanurate of benzodimethyl diisocyanate compound, hydrogenated benzene An isocyanurate of an dimethyl diisocyanate compound, an adduct of a tolylene diisocyanate compound, an adduct of a benzene dimethylene diisocyanate compound, and an adduct of a hydrogenated dimethyl diisocyanate compound.

Further, the above (B) hydroxyl group-containing copolymerizable monomer is selected from the group consisting of 8-hydroxyoctyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Ester, 2-hydroxyethyl (meth)acrylate, N-hydroxy(meth)acrylamide, N-hydroxymethyl(meth)acrylamide, N-hydroxyethyl(meth)acrylamide At least one or more of the compound groups of the composition; and the (A) (C) (C)-C10-C10 (meth) acrylate monomer having 0.1 to 5.0 parts by weight of the above (B) a hydroxyl group-containing copolymerizable monomer; and, in the above (B) hydroxyl group-containing copolymerizable monomer, 8-hydroxyoctyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and ( The total amount of 4-hydroxybutyl methacrylate is 0 to 0.9 parts by weight.

Further, the (C) carboxyl group-containing copolymerizable monomer is selected from the group consisting of (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, and 2-(methyl)acrylic acid.醯oxyethylhexahydrophthalic acid, 2-(methyl)propenyloxypropylhexahydrophthalic acid, 2-(meth)acryloxyethyl phthalate, 2- (Meth) propylene methoxyethyl succinic acid, 2-(meth) propylene oxiranyl ethyl maleic acid, carboxy polycaprolactone mono (meth) acrylate, 2-(methyl) propylene oxime At least one or more of the compound group consisting of oxyethyltetrahydrophthalic acid; a (meth) acrylate monomer having a C4 to C10 carbon number relative to 100 parts by weight of the alkyl group (A) Preferably, it contains 0.35 to 1.0 part by weight of the aforementioned (C) content a copolymerizable monomer of a carboxyl group.

Further, the (D) polyalkylene glycol mono(meth)acrylate monomer is selected from the group consisting of polyalkylene glycol mono(meth)acrylate and methoxypolyalkylene glycol (methyl). At least one of acrylate and ethoxypolyalkylene glycol (meth) acrylate; (C) having a carbon number of C4 to C10 relative to 100 parts by weight of the alkyl group (A) The acrylate monomer preferably contains 1 to 20 parts by weight of the above (D) polyalkylene glycol mono(meth)acrylate monomer.

Further, the (E) vinyl monomer having no hydroxyl group and containing nitrogen is preferably contained in 100 parts by weight of the (meth) acrylate monomer having a C4 to C10 carbon number in the (A) alkyl group. The content of the alkyl (meth) acrylate monomer of the alkoxy group is 1 to 20 parts by weight.

Further, the above-mentioned (F) trifunctional or higher isocyanate compound includes at least one selected from the group consisting of the above (F-1) first aliphatic isocyanate compound group and a second aromatic isocyanate compound selected from the above (F-2). At least one or more of the above, and the total content of the above-mentioned (F) trifunctional or higher isocyanate compound is preferably 0.5 to 5.0 parts by weight based on 100 parts by weight of the copolymer.

Further, it is preferable that the (I) polyether modified siloxane compound is a polyether modified siloxane compound having an HLB value (hydrophilic-lipophilic balance) of 7 to 12, and is contained with respect to 100 parts by weight of the copolymer. 0.01 to 0.5 part by weight of the above (I) polyether modified oxirane compound.

Further, the (G) crosslinking retarder is a ketoenol tautomer compound, and preferably contains 1.0 to 5.0 parts by weight of the (G) crosslinking retarder per 100 parts by weight of the copolymer.

Further, the (H) crosslinking catalyst is an organotin compound, and preferably contains 0.01 to 0.5 part by weight of the above (H) crosslinking catalyst with respect to 100 parts by weight of the above copolymer. Agent.

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

Further, the present invention provides an adhesive film comprising an adhesive layer formed on one surface or both surfaces of a resin film, wherein the adhesive layer is formed by crosslinking the pressure-sensitive adhesive composition.

Further, the present invention provides a surface protective film obtained by forming an adhesive layer on one surface of a resin film, wherein the adhesive layer is formed by crosslinking the adhesive composition, and is characterized in that After the pen is drawn on the surface protective film via the adhesive layer, the contamination is not transferred to the adherend.

Further, the surface protective film of the present invention can be used as a surface protective film of a polarizing plate.

Further, in the surface protective film of the present invention, it is preferred to carry out an antistatic and antifouling treatment on the surface of the resin film opposite to the side on which the adhesive layer is formed.

According to the present invention, it is possible to satisfy all the properties required for the adhesive layer of the surface protective film which cannot be solved in the prior art, and it is possible to prevent the occurrence of the adhesive residue. Specifically, the performance of preventing the sticking agent from sticking can also be improved.

In addition, by using one or more selected from the group consisting of (F-1) the first aliphatic isocyanate compound and one or more selected from the group consisting of the (F-2) second aromatic isocyanate compound, the low-speed peeling region and the low-speed peeling region can be improved. The balance of adhesion in the high speed peeling zone.

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

The adhesive composition of the present invention is characterized in that the main component is a (meth) acrylate monomer having (C) an alkyl group having a C4 to C10 carbon number and (B) a hydroxyl group-containing copolymerizable group. Monomer, (C) carboxyl group-containing copolymerizable monomer, (D) polyalkylene glycol mono(meth)acrylate monomer, and (E) hydroxyl-free and nitrogen-containing vinyl monomer Or an acrylic polymer containing a copolymer of at least one of alkoxyalkyl (meth)acrylate alkyl ester monomers, further containing (F) a trifunctional or higher isocyanate compound, and (G) a crosslinking retarder. And (H) a crosslinking catalyst and (I) a polyether modified siloxane compound, wherein the acrylic polymer has an acid value of 0.01 to 8.0.

Examples of the (meth) acrylate monomer having a CA to C10 carbon atom as the (A) alkyl group include butyl (meth)acrylate, isobutyl (meth)acrylate, and (methyl). Amyl acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ( Ethyl methacrylate, isodecyl (meth)acrylate, decyl (meth)acrylate, and the like.

Examples of the (B) hydroxyl group-containing copolymerizable monomer include 8-hydroxyoctyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. (hydroxy) (meth) acrylate such as 2-hydroxyethyl (meth)acrylate; N-hydroxy(meth) acrylamide, N-methylol (meth) acrylamide, N-hydroxyl A (meth) acrylamide containing a hydroxyl group such as ethyl (meth) acrylamide.

Preferably, the (B) hydroxyl group-containing copolymerizable monomer is selected from the group consisting of 8-hydroxyoctyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Ester, 2-hydroxyethyl (meth)acrylate, N-hydroxy(meth)acrylamide, N-hydroxymethyl(meth)acrylamide, N-hydroxyethyl(meth)acrylamide At least one or more of the compound groups of the composition.

The (meth) acrylate monomer having a C4 to C10 carbon number in the (A) alkyl group is preferably contained in an amount of 0.1 to 5.0 parts by weight based on the above (B) hydroxyl group-containing copolymerizable monomer.

Further, in (B) a hydroxyl group-containing copolymerizable monomer, a total of 8-hydroxyoctyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate The amount is preferably less than 1 part by weight (may not be contained), and more preferably 0 to 0.9 parts by weight.

Preferably, the (C) carboxyl group-containing copolymerizable monomer is selected from the group consisting of (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, and 2-(methyl)acrylonitrile. Ethyl hexahydrophthalic acid, 2-(methyl) propylene methoxypropyl hexahydrophthalic acid, 2-(methyl) propylene methoxyethyl phthalate, 2-(A Acryloxyethyl succinic acid, 2-(methyl) propylene oxiranyl ethyl maleic acid, carboxy polycaprolactone mono (meth) acrylate, 2-(methyl) propylene decyloxy At least one or more of the compound groups consisting of ethyltetrahydrophthalic acid.

The content of the (C) carboxyl group-containing copolymerizable monomer is preferably 0.35 to 1.0 part by weight based on 100 parts by weight of the (A) alkyl group having a C4 to C10 (meth) acrylate monomer. More preferably, it is 0.35-0.6 weight part.

As the (D) polyalkylene glycol mono(meth)acrylate monomer, as long as one of the plurality of hydroxyl groups of the polyalkylene glycol is esterified to (meth)acrylate The compound can be. Since the (meth) acrylate group is a polymerizable group, It is possible to copolymerize with the main polymer. The other hydroxyl group may be in the state of OH, or may be an alkyl ether such as methyl ether or diethyl ether or a saturated carboxylic acid ester such as acetate.

The alkylene group which the polyalkylene glycol has may be a vinyl group, a propenyl group or a butenyl group, but is 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 polytetramethylene glycol. As the copolymer of polyalkylene glycol, polyethylene glycol-polypropylene glycol, polyethylene glycol-polybutylene glycol, polypropylene glycol-polybutylene glycol, polyethylene glycol-polypropylene glycol-poly Butanediol or the like, the copolymer may be a block copolymer or a random copolymer.

As the (D) polyalkylene glycol mono (meth) acrylate monomer, preferably selected from polyalkylene glycol mono (meth) acrylate, methoxy polyalkylene glycol (A At least one of acrylate and ethoxypolyalkylene glycol (meth) acrylate.

More specifically, polyethylene glycol mono- (meth) acrylate, polypropylene glycol mono (meth) acrylate, polybutylene glycol mono (meth) acrylate, polyethylene glycol - polypropylene glycol mono- (meth) acrylate, polyethylene glycol - polybutylene glycol - mono (meth) acrylate, polypropylene glycol - polybutylene glycol - mono (meth) acrylate, polyethylene glycol - polypropylene glycol - polybutylene glycol - mono (meth) acrylate; methoxy polyethylene glycol - (meth) acrylate, methoxy polypropylene glycol - (meth) acrylate, methoxy poly butyl Glycol-(meth) acrylate, methoxy-polyethylene glycol-polypropylene glycol-(meth) acrylate, 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, ethoxylated polybutylene glycol-(meth)acrylate, ethoxy-polyethylene glycol-poly Propylene glycol-(meth) acrylate, ethoxy-polyethylene glycol-polybutylene glycol-(meth) acrylate, ethoxy-polypropylene glycol-polybutylene glycol-(meth) acrylate, B Oxy-polyethylene glycol-polypropylene glycol-polybutylene glycol-(meth)acrylate and the like.

It is preferable to contain 1 to 20 parts by weight of (D) polyalkylene glycol mono(methyl) with respect to 100 parts by weight of the (A) alkyl group having a C4 to C10 (meth) acrylate monomer. ) acrylate monomer.

In (E), as the (E-1) nitrogen-containing vinyl monomer, a vinyl monomer containing a guanamine bond, a vinyl monomer containing an amino group, and a heterocyclic structure having a nitrogen-containing structure may be mentioned. Vinyl monomer and the like. More specifically, N-vinyl-2-pyrrolidone, N-vinylpyrrolidone, methylvinylpyrrolidone, N-vinylpyridine, N-vinylacridone, N-vinylpyrimidine, N-vinylpyridazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N-vinylmorpholine, N-vinylcaprolactam, N a cyclic nitrogen vinyl compound having an N-vinyl substituted heterocyclic ring structure such as vinyl dodecanoin; N-(meth)acryl hydrazinomorpholine, N-(methyl) acrylonitrile fluorene Pyrazine, N-(methyl) acrylonitrile aziridine, N-(methyl) propylene decylpyridinium, N-(methyl) propylene decyl pyrrolidine, N-(methyl) propylene fluorenyl a heterocyclic structure having an N-(meth)acrylinyl group-substituted heterocyclic ring such as acridine, N-(methyl)acrylonitrile-azetidene or N-(methyl)propenylazepane a cyclic nitrogen-vinyl compound; a cyclic nitrogen-oxyethylene having a heterocyclic structure containing a nitrogen atom and a vinyl-based unsaturated bond in the ring, such as N-cyclohexylmaleimide or N-phenylmaleimide. Base compound; (meth) acrylamide, N-methyl (meth) propylene oxime An unsubstituted or monoalkyl-substituted (meth) acrylamide such as N-isopropyl (meth) acrylamide or N-tert-butyl (meth) acrylamide; N,N-dimethyl (Meth) acrylamide, N,N-diethyl(meth) acrylamide, N,N-dipropyl acrylamide, N,N-diisopropyl(meth) acrylamide, N,N-dibutyl (methyl) Acrylamide, N-ethyl-N-methyl(meth)acrylamide, N-methyl-N-propyl(meth)acrylamide, N-methyl-N-isopropyl (A Dialkyl substituted (meth) acrylamide such as acrylamide; N,N-dimethylaminomethyl (meth) acrylate, N,N-dimethylaminoethyl (meth) acrylate Ester, N,N-dimethylaminopropyl (meth) acrylate, N,N-dimethylaminoisopropyl (meth) acrylate, N,N-dimethylaminobutyl (methyl) 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- Dialkylamino (meth) acrylate such as dibutylaminoethyl (meth) acrylate or t-butylaminoethyl (meth) acrylate; N, N-dimethylaminopropyl (methyl) Acrylamide, N,N-diethylaminopropyl(meth)acrylamide, N,N-dipropylaminopropyl(meth)acrylamide, N,N-diisopropylamino Propyl (meth) acrylamide, N -ethyl-N-methylaminopropyl (meth) acrylamide, N-methyl-N-propylaminopropyl (meth) acrylamide, N-methyl-N-isopropylamino N,N-dialkyl substituted aminopropyl (meth) acrylamide such as propyl (meth) acrylamide; N-vinyl carbamide, N-vinyl acetamide, N-vinyl N-vinyl carboxylic acid amide such as N-methylacetamide; N-methoxymethyl (meth) acrylamide, N-ethoxyethyl (meth) acrylamide, N - (Meth) propylene amide, diacetone acrylamide, N, N-methylene bis (meth) acrylamide, etc. (meth) acrylamide; (meth) propylene An unsaturated carboxylic acid nitrile such as a nitrile;

As the (E-1) nitrogen-containing vinyl monomer, it preferably does not contain a hydroxyl group, and more preferably does not contain a hydroxyl group and a carboxyl group. As such a monomer, preferred are the monomers exemplified above, for example, an acrylic monomer containing an N,N-dialkyl substituted amino group or an N,N-dialkyl substituted guanamine group; N-vinyl substituted indoleamine such as N-vinyl-2-pyrrolidone, N-vinyl caprolactam, N-vinyl-2-acridone, N-(Shenyl) acryloylmorpholine, An N-(methyl) acrylonitrile-substituted cyclic amine such as N-(methyl)propenylpyrrolidine.

In (E), as the (E-2) alkoxy group-containing (meth)acrylic acid alkyl ester monomer, 2-methoxyethyl (meth)acrylate and (methyl) may be mentioned. 2-ethoxyethyl acrylate, 2-propoxyethyl (meth)acrylate, 2-isopropoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, ( 2-Methoxypropyl methacrylate, 2-ethoxypropyl (meth) acrylate, 2-propoxypropyl (meth) acrylate, 2-isopropoxy propyl (meth) acrylate Ester, 2-butoxypropyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-ethoxypropyl (meth)acrylate, 3-propoxy (meth)acrylate Propyl propyl ester, 3-isopropoxypropyl (meth) acrylate, 3-butoxypropyl (meth) acrylate, 4-methoxybutyl (meth) acrylate, (meth) acrylate 4 Ethoxybutyl ester, 4-propoxybutyl (meth)acrylate, 4-isopropoxybutyl (meth)acrylate, 4-butoxybutyl (meth)acrylate, and the like.

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

With respect to 100 parts by weight of the (A) alkyl group having a C4 to C10 carbon atom, it is preferred that (E-1) a hydroxyl group-free vinyl monomer or (E- 2) The content of the alkyl (meth) acrylate monomer containing an alkoxy group is 1 to 20 parts by weight. For (E-1) a hydroxyl group-free vinyl monomer and (E-2) an alkoxy group-containing alkyl (meth)acrylate monomer, one type may be used alone or two types may be used together. More than one species.

The (F) trifunctional or higher isocyanate compound may be any polyisocyanate compound having at least three or more isocyanate (NCO) groups in one molecule. . The polyisocyanate compound includes a classification of an aliphatic isocyanate, an aromatic isocyanate, an acyclic isocyanate, an alicyclic isocyanate, and the like, and the present invention may be any of them. Specific examples of the polyisocyanate compound include aliphatic isocyanates such as hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and trimethylhexamethylene diisocyanate (TMDI). a compound; diphenylmethane diisocyanate (MDI), benzodimethyl diisocyanate (XDI), hydrogenated dimethyl diisocyanate (H6XDI), dimethyl diphenylene diisocyanate (TOID), toluene diisocyanate ( An aromatic isocyanate compound such as TDI).

Examples of the trifunctional or higher isocyanate compound include a biuret modified or an isocyanurate modified body of a diisocyanate (a compound having two NCO groups in one molecule), and a trihydroxyl group. An adduct (polyol modified body) of a trivalent or higher polyvalent alcohol (a compound having at least three or more OH groups in one molecule) such as a propane (TMP) or glycerin.

Further, the (F) trifunctional or higher isocyanate compound used in the present invention preferably includes at least one selected from the group consisting of (F-1) first aliphatic isocyanate compounds and selected from (F-2) At least one or more of the group of diaromatic isocyanate compounds, wherein the (F-1) first aliphatic isocyanate compound group is an isocyanurate or isophorone derived from a hexamethylene diisocyanate compound Isocyanurate of an isocyanate compound, an adduct of a hexamethylene diisocyanate compound, an adduct of an isophorone diisocyanate compound, a biuret of a hexamethylene diisocyanate compound, isophorone a biuret of a diisocyanate compound; the (F-2) second aromatic isocyanate compound group is an isocyanurate of a toluene diisocyanate compound, an isocyanuric acid of a benzene dimethylene diisocyanate compound Isocyanurate, toluene diester of ester, hydrogenated dimethyl dimethyl diisocyanate compound An adduct of a cyanate ester compound, an adduct of a benzodimethyl diisocyanate compound, and an adduct of a hydrogenated dimethyl diisocyanate compound. Preferably, (F-1) a first aliphatic isocyanate compound group and (F-2) a second aromatic isocyanate compound group are used in combination. In the present invention, the (F) trifunctional or higher isocyanate compound is used in combination with at least one selected from the group consisting of (F-1) a first aliphatic isocyanate compound and a second aromatic selected from (F-2). At least one or more of the group of isocyanate compounds can further improve the balance of the adhesion in the low-speed peeling region and the high-speed peeling region.

Further, it is preferable that the (F) trifunctional or higher isocyanate compound includes at least one selected from the group consisting of the above (F-1) first aliphatic isocyanate compound group and a second aromatic isocyanate compound selected from the above (F-2). At least one or more of the group, and the total content of the (F) trifunctional or higher isocyanate compound is from 0.5 to 5.0 parts by weight based on 100 parts by weight of the copolymer. Further, as a mixing ratio of at least one or more selected from the group consisting of (F-1) a first aliphatic isocyanate compound group and at least one selected from the group consisting of (F-2) a second aromatic isocyanate compound, The weight ratio calculation is preferably (F-1): (F-2) in the range of 10%: 90% to 90%: 10%.

As the (G) cross-linking retarder, there may be mentioned ethyl acetonitrile acetate, ethyl acetate, octyl acetate, ethyl acetoacetate, lauryl acetate, and ethyl acetate. a β-ketoester such as an oxime ester; a β-diketone such as acetamidineacetone, 2,4-hexanedione or benzamidineacetone. These are ketoenol tautomer compounds, and in the adhesive composition using a polyisocyanate compound as a crosslinking agent, by blocking the isocyanate group which the crosslinking agent has, it can suppress adhesion after a crosslinking agent. The phenomenon that the viscosity of the agent composition is excessively increased or gelled can prolong the shelf life of the adhesive composition.

Preferably, the (G) crosslinking blocker is a ketoenol tautomer compound, and particularly preferably selected At least one or more of the compound groups consisting of free ethyl acetonide and ethyl acetate.

The content of the (G) crosslinking blocker is preferably 1.0 to 5.0 parts by weight based on 100 parts by weight of the copolymer.

When the polyisocyanate compound is used as the crosslinking agent, the (H) crosslinking catalyst may be one which functions as a catalyst for the reaction (crosslinking reaction) between the copolymer and the crosslinking agent, and may be mentioned. An amine compound such as a tertiary amine, an organotin compound such as an organotin compound, an organic lead compound or an organozinc compound.

Examples of the tertiary amine include trialkylamine, N,N,N',N'-tetraalkyldiamine, N,N-dialkylamino alcohol, triethylenediamine, and morpholine derivatives. Pyridazine derivatives and the like.

Examples of the organotin compound include a dialkyl tin oxide, a fatty acid salt of a dialkyl tin, a fatty acid salt of stannous, and the like.

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

The content of the (H) crosslinking catalyst is preferably 0.01 to 0.5 parts by weight based on 100 parts by weight of the copolymer.

(I) The polyether modified siloxane compound is a siloxane compound having a polyether group, and has a polyether group-containing oxime in addition to the usual siloxane unit (-SiR ¹ ₂ -O-) Alkane unit (-SiR ¹ (R ² O(R ³ O) _n R ⁴ )-O-). Here, R ¹ represents one or two or more alkyl groups or aryl groups; R ² and R ³ represent one or two or more alkylene groups; and R ⁴ represents one or two or more alkyl groups, fluorenyl groups and the like ( End base). The polyether group may, for example, be a polyoxyalkylene group such as a polyoxyethylene group ((C ₂ H ₄ O) _n ) or a polyoxypropylene group ((C ₃ H ₆ O) _n ).

Preferably, the (I) polyether modified oxirane compound is a polyether modified oxirane compound having an HLB value of 7-12. Further, the content of the (I) polyether modified siloxane compound is preferably 0.01 to 0.5 part by weight, more preferably 0.1 to 0.5 part by weight, per 100 parts by weight of the copolymer.

HLB is a predetermined hydrophilic-lipophilic balance (ratio of hydrophilicity to lipophilicity) such as JIS K3211 (surfactant term).

The polyether modified oxoxane compound can be obtained, for example, by grafting an organic compound having an unsaturated bond and a polyoxyalkylene group to a polyorganosiloxane having a decyl group by a hydrogenation oximation reaction. Obtained from the main chain. Specifically, a dimethyl methoxy oxane-methyl (polyoxyethylene) decane copolymer, dimethyl methoxy oxane-methyl (polyoxyethylene) decane-methyl (poly) A propylene oxide) siloxane copolymer, a dimethyl methoxy oxane-methyl (polyoxypropylene) siloxane copolymer, or the like. By blending the (I) polyether modified siloxane compound with the adhesive composition, the adhesion and reworkability of the adhesive can be improved.

Further, as other components, a copolymerizable (meth)acrylic monomer, a (meth)acrylamide monomer, a dialkyl-substituted acrylamide monomer containing an alkylene oxide may be appropriately blended. A known additive such as a surfactant, a hardening accelerator, a plasticizer, a filler, a hardening retarder, a processing aid, an anti-aging agent, an antioxidant, and an antistatic agent. These may be used alone or in combination of two or more.

As the antistatic agent, an ionic compound can be mentioned. Further, by copolymerizing an ionic acrylic monomer on a copolymer as a main component, it is possible to impart antistatic properties.

The main agent copolymer used in the adhesive composition of the present invention can be obtained by copolymerizing a (meth) acrylate monomer having (C) an alkyl group having a C4 to C10 carbon number, and (B) a hydroxyl group-containing copolymer. Monomer, (C) carboxyl group-containing copolymerizable monomer, and (D) poly Asian The alkyl diol mono(meth) acrylate monomer is synthesized by polymerization. The polymerization method of the copolymer is not particularly limited, and an appropriate polymerization method such as solution polymerization or emulsion polymerization can be used.

The adhesive composition of the present invention may be prepared by blending (F) a trifunctional or higher isocyanate compound, (G) a crosslinking retarder, (H) a crosslinking catalyst, and (I) a polyether in the above copolymer. The oxirane compound, along with any suitable additives, is formulated.

The copolymer is preferably an acrylic polymer, and preferably contains 50 to 100% by weight of a (meth) acrylate monomer or an acrylic monomer such as (meth)acrylic acid or (meth)acrylamide.

Further, it is preferred that the acrylic polymer has an acid value of 0.01 to 8.0. Thereby, it is possible to improve the staining property and improve the performance of preventing the occurrence of the adhesive residue.

Here, the "acid value" is one of the indexes indicating the acid content, and is expressed by the number of mg of potassium hydroxide required to neutralize 1 g of the carboxyl group-containing polymer.

Preferably, the adhesive layer obtained by crosslinking the above-mentioned adhesive composition has an adhesive force of 0.05 to 0.1 N/25 mm at a low peeling speed of 0.3 m/min, and an adhesive force of 1.0 at a high peeling speed of 30 m/min. N/25mm or less. Thereby, it is possible to obtain a performance in which the change in the adhesive force with the peeling speed is small, and it is possible to quickly peel off even in the case of high-speed peeling. Further, even if the surface protective film is temporarily peeled off for re-adhesion, it does not require excessive force and is easily peeled off from the adherend.

The adhesive layer (adhesive after crosslinking) obtained by crosslinking the pressure-sensitive adhesive composition of the present invention preferably has a gel fraction of 95 to 100%. Since the gel fraction is so high, the adhesion does not become excessive at a low peeling speed, and the phenomenon of eluting unpolymerized monomers or oligomers from the copolymer is lowered, so that reworkability and high temperature can be improved. Durability under high humidity and suppression of contamination by adherends.

The pressure-sensitive adhesive film of the present invention is obtained by forming an adhesive layer on one or both sides of a resin film which is obtained by crosslinking the pressure-sensitive adhesive composition of the present invention. Further, the surface protective film of the present invention is obtained by forming an adhesive layer on one surface of a resin film which is obtained by crosslinking the pressure-sensitive adhesive composition of the present invention. In the adhesive composition of the present invention, since the respective components (A) to (I) are blended in a good balance, the balance of the adhesive force at a low peeling speed and a high peeling speed is excellent. Moreover, it is excellent also in durability and reworkability (after being drawn on the surface protective film with the pen atom through the adhesive layer, it is not contaminated by the adherend). Therefore, it can be preferably used as a surface protective film of a polarizing plate.

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

The base film can be formed on the surface of the resin film opposite to the side on which the pressure-sensitive adhesive layer layer is formed by an anthrone or a fluorine-based release agent, a coating agent, cerium oxide particles or the like. The antifouling treatment can be carried out by an antistatic treatment by application or mixing of an antistatic agent.

In the release film, a release treatment by an anthrone or a fluorine release agent is performed on the surface on the side where the adhesive surface of the pressure-sensitive adhesive layer is bonded.

Example

Hereinafter, the present invention will be specifically described based on examples.

<Manufacture of Acrylic Copolymer> [Example 1]

Nitrogen gas was introduced into a reaction apparatus equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen introduction tube, and the air in the reaction apparatus was replaced with nitrogen. Then, 100 parts by weight of 2-ethylhexyl acrylate, 0.9 parts by weight of 8-hydroxyoctyl acrylate, 0.5 parts by weight of acrylic acid, and 3 parts by weight of polyethylene glycol monoacrylate were added to the reaction apparatus. 5 parts by weight of N-vinylpyrrolidone, and 60 parts by weight of a solvent (ethyl acetate) were simultaneously added. Then, 0.1 part by weight of azobisisobutyronitrile as a polymerization initiator was added dropwise over 2 hours, and the mixture was reacted at 65 ° C for 6 hours to obtain a weight average molecular weight of 500,000, which was used in the examples. 1 acrylic copolymer solution 1. A part of the acrylic copolymer was used as an acid value measurement sample to be described later.

[Examples 2 to 9 and Comparative Examples 1 to 4]

The operation was carried out in the same manner as in the above-described acrylic copolymer solution 1 of Example 1 except that the composition of each monomer was adjusted as described in (A) to (E) in Table 1, and the examples were obtained. The acrylic copolymer solution of 2 to 9 and Comparative Examples 1 to 4.

<Manufacture of Adhesive Composition and Surface Protective Film> [Example 1]

To the acrylic copolymer solution 1 of Example 1 produced as described above, 0.2 parts by weight of KF-351A (polyether modified oxirane compound of HLB=12) and 2.5 parts by weight of acetylacetone were added and stirred, and then added. 1.0 part by weight of Coronate HX ( HX, isocyanurate of hexamethylene diisocyanate compound, 0.2 parts by weight of Coronate L ( L, an adduct of a toluene diisocyanate compound and trimethylolpropane), and 0.02 part by weight of dioctyltin dilaurate were stirred and mixed to obtain an adhesive composition of Example 1. The adhesive composition was applied onto a release film composed of a polyethylene terephthalate (PET) film coated with an fluorenone resin, and then dried at 90 ° C to remove the solvent to obtain adhesion. The adhesive layer had a thickness of 25 μm.

Then, a polyethylene terephthalate (PET) film having an antistatic treatment and an antifouling treatment on one surface is prepared, and the adhesive sheet is transferred to the polyethylene terephthalate (PET) film. On the opposite side of the surface on which the antistatic treatment and the antifouling treatment were carried out, a PET film/adhesive layer/release film (PET film coated with an anthrone resin) having antistatic treatment and antifouling treatment was obtained. The surface protective film of Example 1 which is laminated.

[Examples 2 to 9 and Comparative Examples 1 to 4]

Except that the composition of each additive was adjusted as described in (F) to (I) of Table 2, the same operation as the surface protective film of Example 1 was carried out, and Examples 2 to 9 and Comparative 1 to 4 were obtained. Surface protection film.

Table 2

Table 1 and Table 2 are tables in which the entire table showing the mixing ratio of each component is divided into two parts, and the numerical values in the parentheses indicate the weights of the respective components obtained by setting the total weight of the group (A) to 100 parts by weight. Value. Further, the names of the compounds corresponding to the abbreviations of the respective components used in Tables 1 and 2 are shown in Tables 3 and 4. In addition, Coronate ( , registered trademark) HX, Coronate HL and Coronate L are the trade names of Nippon Polyurethane Industry Co., Ltd., Takenate ( , registered trademark) D-140N, D-127N, D-110N, D-120N are trade names of Mitsui Chemicals Co., Ltd., KF-35lA, KF-352A, KF-353, KF-640 and X-22-6191 It is the trade name of Shin-Etsu Chemical Co., Ltd.

table 3

Table 4

<Test method and evaluation>

The surface protective films of Examples 1 to 9 and Comparative Examples 1 to 4 were aged for 7 days in an environment of 23 ° C and 50% RH, and then the release film (PET film coated with an anthrone resin) was peeled off to make it sticky. The agent layer was exposed and used as a sample for determining the gel fraction.

Further, the surface protective film exposed to the adhesive layer was bonded to the surface of the polarizing plate adhered to the liquid crystal cell through an adhesive layer, and left for 1 day, and then subjected to autoclave treatment at 50 ° C and 5 atm for 20 minutes. Further, it was allowed to stand at room temperature for 12 hours, and the surface protective film thus obtained was used as a sample for measuring adhesion and durability.

<acid value>

Acid value of acrylic polymer: The sample is dissolved in a solvent (a solvent in which diethyl ether and ethanol are mixed at a volume ratio of 2:1), and an electric potential difference automatic titrator (AT-610, manufactured by Kyoto Electronics Industry Co., Ltd.) is used. ), potentiometric titration was carried out with a potassium hydroxide ethanol solution having a concentration of about 0.1 mol/L, and the amount required for neutralizing the sample was measured. The amount of potassium hydroxide in ethanol solution. Then, the acid value was determined according to the following formula.

Acid value = (B × f × 5.611) / S

B = amount of 0.1 mol/L potassium hydroxide ethanol solution used in the titration (mL)

f=0.1mol/L coefficient of potassium hydroxide ethanol solution

S = quality of the solid component of the sample (g)

<gel fraction>

The quality of the measurement sample after the aging was completed and before the polarizing plate was bonded was accurately measured, and after immersing in toluene for 24 hours, it was filtered through a 200 mesh mesh. Then, after drying the filtrate at 100 ° C for 1 hour, the quality of the residue was accurately measured, and the gel fraction of the adhesive layer (adhesive after crosslinking) was calculated according to the following formula.

Gel fraction (%) = insoluble portion quality (g) / adhesive quality (g) × 100

<adhesion>

Using a tensile tester, the above-obtained measurement sample was peeled off at a low peeling speed (0.3 m/min) and a high peeling speed (30 m/min) in a 180° direction (a 25 mm wide surface protective film was attached to the polarized light). The sample formed on the surface of the plate was measured for peel strength, and the peel strength was used as the adhesion.

<Reworkability>

The surface protective film of the measurement sample obtained above was drawn with a ball pen (loading was 500 g, three times back and forth), and the surface protective film was peeled off from the polarizing plate, and the surface of the polarizing plate was observed, and it was confirmed that no contamination was transferred to the polarizing plate. Evaluation target criterion: when the contamination is not transferred to the polarizing plate, it is evaluated as "○"; when it is confirmed that the trajectory drawn along the atomic pen is at least partially transferred to the pollution, it is evaluated as "△"; when it is confirmed that the trajectory drawn along the atomic pen has The contamination was transferred and evaluated as "X" when the adhesion of the adhesive was also confirmed from the surface of the adhesive.

<Durability>

After the measurement sample obtained above was placed in an environment of 60 ° C and 90% RH for 250 hours, it was taken out and left at room temperature for further 12 hours, and then the adhesion was measured, and it was confirmed that there was no significant difference from the initial adhesion. increase. Evaluation target criterion: When the adhesion after the test was 1.5 times or less of the initial adhesion, it was evaluated as "○", and when it was more than 1.5 times, it was evaluated as "X".

The evaluation results are shown in Table 5.

For the surface protective films of Examples 1 to 9, the adhesive strength at a low peeling speed of 0.3 m/min was 0.05 to 0.1 N/25 mm, and the adhesive force at a high peeling speed of 30 m/min was 1.0 N/25 mm or less. In addition, after the surface protective film is drawn through the adhesive layer with the pen holder, the contamination is not transferred to the adherend, and the durability after leaving it for 250 hours in an environment of 60 ° C and 90% RH is excellent. of.

That is, all of the following performance requirements are satisfied: (1) achieving balance of adhesion at a low peeling speed and a high-speed peeling speed; (2) preventing occurrence of adhesive residue; and (3) reworkability.

Further, by using together the (F-1) first aliphatic isocyanate compound group One or more types selected from the group consisting of (F-2) second aromatic isocyanate compounds can improve the balance of the adhesion between the low-speed peeling region and the high-speed peeling region.

The surface protective film of Comparative Example 1 had a gel fraction of 0, an excessive adhesion at a low peeling speed of 0.3 m/min, and a high peeling speed of 30 m/min, and poor reworkability and durability, which may be Since (D) polyalkylene glycol mono(meth)acrylate monomer and (E) nitrogen-containing vinyl monomer or alkoxy-containing alkyl (meth)acrylate monomer are not contained and F) The reason for the isocyanate compound.

The surface protective film of Comparative Example 2 had excessive adhesion at a low peeling speed of 0.3 m/min and a high peeling speed of 30 m/min, excessive reworkability and durability, and low gel fraction. This may be due to (B) too little hydroxyl group-containing monomer, (D) polyalkylene glycol mono(meth)acrylate monomer too small, excluding (E) nitrogen-containing vinyl monomer or containing alkane The HLB value of the (meth)acrylic acid alkyl ester monomer of the oxy group and the (I) polyether modified siloxane compound is too small.

The surface protective film of Comparative Example 3 had a short storage period, and since it was crosslinked before coating, coating could not be performed. This may be because the (F) isocyanate compound was excessive and uncoordinated (G). The reason for cross-linking retarders.

The surface protective film of Comparative Example 4 had a storage period too short even if it did not contain the (H) crosslinking catalyst, and since it was crosslinked before coating, coating could not be performed, which may be due to (F) Excessive isocyanate compound.

As described above, in the surface protective films of Comparative Examples 1 to 4, it is not possible to simultaneously satisfy all of the following performance requirements: (1) achieving balance of adhesion at a low peeling speed and a high peeling speed; (2) preventing adhesion The occurrence of agent residues; and (3) reworkability.

Industrial utilization

The adhesive composition according to the present invention can satisfy all the properties required for the adhesive layer of the surface protective film which cannot be solved in the prior art, and can also prevent the occurrence of adhesive residue. Further, since the surface protective film of the present invention improves the balance of the adhesive force in the low-speed peeling region and the high-speed peeling region, it is industrially valuable.

Claims (20)

An adhesive composition, wherein the adhesive composition is composed of an acrylic polymer comprising a copolymer having an acrylic polymer containing (A) an alkyl group having a carbon number of C4 to C10 ( (meth) acrylate monomer, (B) hydroxyl group-containing copolymerizable monomer, (C) carboxyl group-containing copolymerizable monomer, (D) polyalkylene glycol mono (meth) acrylate monomer And (E) at least one of a hydroxyl group-free nitrogen-containing vinyl monomer or an alkoxy group-containing alkyl (meth)acrylate monomer, and further contains (F) a trifunctional or higher isocyanate compound, (G) a crosslinking retarder, (H) a crosslinking catalyst, and (I) a polyether modified siloxane compound having an acid value of 0.01 to 8.0, said (F) trifunctional The above isocyanate compound includes at least one selected from the group consisting of (F-1) a first aliphatic isocyanate compound group and at least one selected from the group consisting of (F-2) a second aromatic isocyanate compound. The adhesive composition according to claim 1, wherein the (F-1) first aliphatic isocyanate compound group in the (F) trifunctional or higher isocyanate compound is composed of six Isocyanurate of methylene diisocyanate compound, isocyanurate of isophorone diisocyanate compound, adduct of hexamethylene diisocyanate compound, adduct of isophorone diisocyanate compound a biuret composition of a hexamethylene diisocyanate compound and a biuret composition of an isophorone diisocyanate compound, wherein the (F-2) second aromatic isocyanate compound group is different from a toluene diisocyanate compound. Isocyanurate, isocyanurate of benzodimethyl diisocyanate compound, isocyanurate of hydrogenated dimethylated diisocyanate compound, adduct of toluene diisocyanate compound, benzenedimethyl An adduct of a diisocyanate compound and an adduct of a hydrogenated dimethylenedi-isocyanate compound. The adhesive composition according to claim 1 or 2, wherein the (B) hydroxyl group-containing copolymerizable monomer is selected from the group consisting of 8-hydroxyoctyl (meth)acrylate. Ester, 6-hydroxyhexyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, N-hydroxy(meth)acrylamide, N-hydroxyl At least one or more of the compound group consisting of a base (meth) acrylamide and N-hydroxyethyl (meth) acrylamide is a carbon number of 100 parts by weight of the (A) alkyl group. a (meth) acrylate monomer of C4 to C10, containing 0.1 to 5.0 parts by weight of the (B) hydroxyl group-containing copolymerizable monomer, and (B) a hydroxyl group-containing copolymerizable monomer The total amount of 8-hydroxyoctyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate is 0 to 0.9 parts by weight. The adhesive composition according to claim 1 or 2, wherein the (C) carboxyl group-containing copolymerizable monomer is selected from (meth)acrylic acid, (methyl) Carboxyethyl acrylate, carboxypentyl (meth)acrylate, 2-(methyl)propenyloxyethylhexahydrophthalic acid, 2-(methyl)propenyloxypropylhexahydroortylene Dicarboxylic acid, 2-(meth)acryloxyethyl phthalate, 2-(methyl) propylene methoxyethyl succinic acid, 2-(methyl) propylene methoxyethyl maleic acid At least one or more of a compound group consisting of carboxypolycaprolactone mono(meth)acrylate and 2-(meth)acryloxyethyltetrahydrophthalic acid, relative to 100 parts by weight The (A) alkyl group has a C4 to C10 (meth) acrylate monomer, and contains 0.35 to 1.0 part by weight of the (C) carboxyl group-containing copolymerizable monomer. The adhesive composition according to claim 3, wherein the (C) carboxyl group-containing copolymerizable monomer is selected from (meth)acrylic acid, carboxyethyl (meth)acrylate , (meth)acrylic acid carboxypentyl ester, 2-(meth)acryloxyethyl hexahydrophthalic acid, 2-(methyl)acryloxypropyl hexahydrophthalic acid, 2- (methyl) propylene 醯oxyethylphthalic acid, 2-(methyl)propenyloxyethyl succinic acid, 2-(methyl) propylene oxiranyl ethyl maleic acid, carboxypolycaprolactone mono (methyl At least one or more of the compound group consisting of acrylate and 2-(meth)acryloxyethyltetrahydrophthalic acid, and the number of carbon atoms of the (A) alkyl group relative to 100 parts by weight The (meth) acrylate monomer which is C4 to C10 contains 0.35 to 1.0 part by weight of the (C) carboxyl group-containing copolymerizable monomer. The adhesive composition according to claim 1 or 2, wherein the (D) polyalkylene glycol mono(meth)acrylate monomer is selected from the group consisting of polyalkylene groups. At least one of diol mono(meth)acrylate, methoxypolyalkylene glycol (meth) acrylate, ethoxypolyalkylene glycol (meth) acrylate, relative to 100 The (A) alkyl group has a C4 to C10 (meth) acrylate monomer in a weight ratio of 1 to 20 parts by weight of the (D) polyalkylene glycol mono (methyl group). ) acrylate monomer. The adhesive composition according to claim 3, wherein the (D) polyalkylene glycol mono(meth)acrylate monomer is selected from the group consisting of polyalkylene glycols ( At least one or more of methyl acrylate, methoxy polyalkylene glycol (meth) acrylate, and ethoxy polyalkylene glycol (meth) acrylate, relative to 100 parts by weight The (A) alkyl group has a C4 to C10 (meth) acrylate monomer, and contains 1 to 20 parts by weight of the (D) polyalkylene glycol mono(meth) acrylate monomer. body. The adhesive composition according to claim 4, wherein the (D) polyalkylene glycol mono(meth)acrylate monomer is selected from the group consisting of polyalkylene glycols ( At least one or more of methyl acrylate, methoxy polyalkylene glycol (meth) acrylate, and ethoxy polyalkylene glycol (meth) acrylate, relative to 100 parts by weight The (A) alkyl group has a C4 to C10 (meth) acrylate monomer, and contains 1 to 20 parts by weight of the (D) polyalkylene glycol mono(meth) acrylate monomer. body. The adhesive composition according to claim 5, wherein the (D) polyalkylene glycol mono(meth)acrylate monomer is selected from the group consisting of polyalkylene glycols ( At least one or more of methyl acrylate, methoxy polyalkylene glycol (meth) acrylate, and ethoxy polyalkylene glycol (meth) acrylate, relative to 100 parts by weight The (A) alkyl group has a C4 to C10 (meth) acrylate monomer, and contains 1 to 20 parts by weight of the (D) polyalkylene glycol mono(meth) acrylate monomer. body. The adhesive composition according to claim 1 or 2, wherein the (A) alkyl group has a C4 to C10 (methyl) group with respect to 100 parts by weight of the (A) alkyl group. The acrylate monomer contains 1 to 20 parts by weight of the (E) hydroxyl group-free nitrogen-containing vinyl monomer or alkoxy group-containing alkyl (meth)acrylate monomer. The adhesive composition according to claim 3, wherein the (A) alkyl group has a C4 to C10 (meth) acrylate monomer with respect to 100 parts by weight of the (A) alkyl group. And containing 1 to 20 parts by weight of the (E) hydroxyl group-free nitrogen-containing vinyl monomer or alkoxy group-containing alkyl (meth)acrylate monomer. The adhesive composition according to claim 1 or 2, wherein the (F) trifunctional or higher isocyanate compound comprises the (F-1) first aliphatic isocyanate compound. At least one or more of the group and at least one selected from the group consisting of the (F-2) second aromatic isocyanate compound, the (F) trifunctional or higher with respect to 100 parts by weight of the copolymer The total content of the isocyanate compound is from 0.5 to 5.0 parts by weight. The adhesive composition according to claim 1 or 2, wherein the (I) polyether modified siloxane compound is a polyether modified oxirane having an HLB value of 7-12. Compound, The (I) polyether modified siloxane compound is contained in an amount of 0.01 to 0.5 part by weight based on 100 parts by weight of the copolymer. The adhesive composition according to claim 1 or 2, wherein the (G) crosslinking blocker is a ketoenol tautomer compound, and the copolymer is copolymerized with respect to 100 parts by weight. And containing 1.0 to 5.0 parts by weight of the (G) crosslinking blocker. The adhesive composition according to claim 1 or 2, wherein the (H) crosslinking catalyst is an organotin compound, and contains 0.01 to 0.5 with respect to 100 parts by weight of the copolymer. The (H) crosslinking catalyst is part by weight. The adhesive composition according to claim 1 or 2, wherein the adhesive layer obtained by crosslinking the adhesive composition has a viscosity at a low peeling speed of 0.3 m/min. The force is 0.05 to 0.1 N/25 mm, and the adhesion at a high peeling speed of 30 m/min is 1.0 N/25 mm or less. An adhesive film comprising an adhesive layer formed on one side or both sides of a resin film, the adhesive layer being one of items 1 to 16 of the patent application scope The adhesive composition described is crosslinked. A surface protective film which is formed by forming an adhesive layer on one side of a resin film, the adhesive layer being an adhesive combination according to any one of claims 1 to 16. The cross-linking of the article is characterized in that after the surface of the adhesive film is drawn on the surface protective film with a ball pen, no contamination is transferred to the adherend. The surface protective film according to claim 18, which is used as a surface protective film for a polarizing plate. The surface protection film according to claim 18, wherein an antistatic layer is applied to a surface of the resin film opposite to a side on which the adhesive layer is formed. Antifouling treatment.