KR20200054887A - Adhesive composition, and adhesive film, surface-protective film using the same - Google Patents

Abstract

Disclosed are an adhesive composition to have adhesive power balanced in slow peeling speed and high peeling speed and to plan compatibility of an antistatic performance and a pollution resistance performance, and an adhesive film and a surface-protective film using the same. The adhesive composition comprises an acrylic polymer. The acrylic polymer is formed by a copolymer having a weight average molecular weight of 300,000 to 1,000,000 and having acid value of 0.1-1.0 obtained by copolymerizing (A) a sum 100 parts by weight of at least two of alkyl (meth) acrylate having carbon number C1-C10 of an alkyl group; (B) a copolymerizable monomer 1.0-6.0 parts by weight containing a hydroxyl group; (C) acopolymerizable monomer 0.1-0.6 parts by weight containing a carboxyl group. The acrylic polymer comprises 2-ethylhexyl acrylate and at least one monofunctional methacrylate polymer in the range of 2-ethylhexyl acrylate 50 parts by weight or greater; and a sum 5-40 parts by weight of at least one monofunctional methacrylate polymer having Tg of 0°C or higher of homo polymer.

Description

Adhesive composition, adhesive film using the same, surface protection film {ADHESIVE COMPOSITION, AND ADHESIVE FILM, SURFACE-PROTECTIVE FILM USING THE SAME}

The present invention relates to a pressure-sensitive adhesive composition that can be preferably used for a surface protection film such as a surface protection film for a polarizing plate, an adhesive film using the same, and a surface protection film. More specifically, the present invention relates to a pressure-sensitive adhesive composition capable of achieving a balance between antistatic performance and fouling resistance, and a pressure-sensitive adhesive film using the same, and a surface protection film, which have balanced adhesion in a low-speed peeling speed and a high-speed peeling speed. .

Conventionally, in the manufacturing process of an optical member such as a polarizing plate which is a member constituting a liquid crystal display, a surface protection film is pasted for temporary protection of the surface of the optical member. Such a surface protection film is used only in the process of manufacturing the optical member, and is removed by peeling from the optical member at the time of including the optical member as a liquid crystal display. Since the surface protective film for protecting the surface of the optical member is used only in the manufacturing process of the optical member, it is also commonly referred to as a process film.

The surface protection film used in the process of manufacturing an optical member as described above has a configuration in which an adhesive layer is formed on one surface of an optically transparent polyethylene terephthalate (PET) resin film. In addition, a release film subjected to a release treatment to protect the pressure-sensitive adhesive layer is pasted on the surface of the pressure-sensitive adhesive layer of the surface protection film until it is pasted to the optical member.

Then, an optical member such as a polarizing plate is subjected to a product inspection involving optical evaluation such as display ability, color, contrast, foreign matter mixing, etc. of the liquid crystal display panel in a state where the surface protection film is pasted. For this reason, as the required performance for the surface protective film, bubbles or foreign substances are not mixed in the pressure-sensitive adhesive layer, and it is possible to reduce the adhesion of the low-molecular-weight component of the pressure-sensitive adhesive composition to the surface of the adherend, that is, contamination resistance It is required to have.

In addition, when peeling the surface protective film from an optical member such as a polarizing plate, there is concern that peeling charge generated with static electricity generated when the pressure-sensitive adhesive layer peels off the adherend may cause a failure of the electric control circuit of the liquid crystal display. For this reason, the adhesive layer of the surface protection film is required to have excellent antistatic performance.

In addition, in recent years, as a polarizer protective layer (also called a protective film) of a polarizing plate, in addition to conventionally used triacetyl cellulose (TAC), acrylic resins such as polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), etc. When peeling off the surface protection film of polarizing plates, such as polyester resin, cyclic olefin polymer, and polycarbonate, the adoption of the material which is easy to generate peeling charge is expanding. For this reason, it is required that the antistatic performance required for the pressure-sensitive adhesive layer for the surface protective film of the polarizing plate is superior to the conventional one.

Moreover, when peeling a surface protection film from an optical member, such as a polarizing plate, finally, it is necessary to be able to peel quickly. It is required that there is little change in the adhesive force even if the peeling speed fluctuates so that peeling can be performed quickly even by so-called high-speed peeling.

As such, in recent years, the pressure-sensitive adhesive layer constituting the surface protection film has (1) a balance of adhesion at low-speed peeling speed and a high-speed peeling speed, (2) one having anti-pollution performance, (3) excellent charging What has a preventive performance etc. is calculated | required from the point of the ease of use in using a surface protection film.

However, (1) to (3) required for the pressure-sensitive adhesive layer of the surface protection film, although each of these (1) to (3) can satisfy each required performance with respect to the performance required for the pressure-sensitive adhesive layer constituting the surface protection film. It was a very difficult task to satisfy all the required performances of (3) at the same time.

In order to solve such a problem, for example, (1) having a balance of adhesive force at low-speed peeling speed and high-speed peeling speed, (2) having fouling resistance, and (3) having excellent antistatic performance For each, the following proposals are known.

(1) With respect to the balance of adhesive strength at low-speed peeling speed and high-speed peeling speed, 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 is a main component, and this is used as a crosslinking agent. It is known to apply an acrylic pressure-sensitive adhesive layer formed by cross-linking treatment. However, in such an adhesive layer, when adhered for a long time, adhesion of the pressure sensitive adhesive to the adherend side occurs, and there is a problem that the synergism of the adhesive force with respect to the adherend is large. To avoid this, a copolymer of a (meth) acrylic acid alkyl ester having an alkyl group having 8 to 10 carbon atoms and a copolymerizable compound having an alcoholic hydroxyl group is used, and the gel layer crosslinked with a crosslinking agent has a pressure-sensitive adhesive layer of 60% or more, and A surface protection member having an adhesive layer is known (Patent Document 1).

However, in the pressure-sensitive adhesive layer described in Patent Document 1, there is a problem that it is not possible to completely solve that the adhesion to the adherend rises with time.

It is also known that a copolymer of a (meth) acrylic acid alkyl ester and a carboxyl group-containing copolymerizable compound is blended in the same copolymer as described above, and a pressure-sensitive adhesive layer crosslinked with a crosslinking agent is formed. However, these pressure-sensitive adhesive layers have low surface tension, and when used to protect the surface of a smooth plastic plate or the like, problems such as exfoliation due to heating during processing or preservation, or high-speed peeling speed in a manual area There was also a problem in that the re-peelability was poor due to the large adhesive force in.

In order to solve these problems, a) 100 parts by weight of (meth) acrylic acid alkyl ester mainly composed of (meth) acrylic acid alkyl ester having an alkyl group having 8 to 10 carbon atoms, b) 1 to 15 weight of carboxyl group-containing copolymerizable compound A pressure-sensitive adhesive composition in which a copolymer of a monomer mixture comprising parts and c) 3 to 100 parts by weight of a vinyl ester of an aliphatic carboxylic acid having 1 to 5 carbon atoms is added to the carboxyl group of the component b) is added in an amount equivalent to a crosslinking agent. It has been proposed (Patent Document 2).

In the pressure-sensitive adhesive layer in which the pressure-sensitive adhesive composition described in Patent Literature 2 is crosslinked, peeling phenomena such as exfoliation do not occur during processing or storage, and also, the synergism of the adhesive strength is small over time, and thus excellent in removability, and long-term storage, especially at high temperature It is said that even if it is stored for a long time in an atmosphere, it can be peeled off with a small force, and no residue is generated on the adherend at that time, and it is also possible to peel it off with a small force even when high-speed peeling is performed.

However, in the pressure-sensitive adhesive layer in which the pressure-sensitive adhesive composition described in Patent Document 2 is crosslinked, the gel fractions of the pressure-sensitive adhesive layers in Examples 1 to 3 are all 90%, and the adhesive force at low-speed peeling rates tends to be excessive, and the pressure-sensitive adhesive layer is not easily removed. Polymerized monomers or oligomers tend to elute. In addition, Patent Document 2 does not describe the antistatic performance and the anti-pollution performance, and it is difficult to improve the pressure-sensitive adhesive layer with excellent anti-static and anti-pollution performance when a material that is prone to peeling electrification is used as an adherend. There was a problem.

In addition, (2) with respect to the anti-pollution performance, 0 parts by mass or more and less than 0.5 parts by mass of carboxyl group-containing monomers, 0.6 to 9 parts by mass of hydroxy group-containing (meth) acrylic monomers and 99.4 to 90.5 parts by mass of (meth) acrylic acid ester monomers 100 parts by weight of a (meth) acrylic copolymer having a weight average molecular weight of 100,000 or more and less than 1 million; And an adhesive composition comprising 0.1 to 5 parts by mass of a carbodiimide-based crosslinking agent (Patent Document 3).

In the pressure-sensitive adhesive composition described in Patent Document 3, a carbodiimide-based crosslinking agent is used as a crosslinking agent for a (meth) acrylic copolymer having a specific composition. Thereby, it is possible to provide the pressure-sensitive adhesive layer having a crosslinked structure capable of following shrinkage due to pressure and temperature during the autoclave treatment. For this reason, the pressure-sensitive adhesive layer formed using the pressure-sensitive adhesive composition described in Patent Literature 3 can suppress and prevent foaming even under high temperature and high pressure conditions (at the time of autoclave treatment), has excellent stain resistance, and is also excellent in transparency. .

However, in the pressure-sensitive adhesive layer in which the pressure-sensitive adhesive composition described in Patent Document 3 is crosslinked, the stain resistance performance is improved, but by having a balance of adhesion between low-speed peeling speed and high-speed peeling speed, excellent adhesion performance and antistatic performance are both achieved. This cannot be realized and remains a further challenge.

Moreover, as for the method (3) having excellent antistatic performance, a method of kneading an antistatic agent in a base film is known as a method for imparting antistatic property to a surface protection film. As the antistatic agent, for example, (a) various cationic antistatic agents having cationic groups such as quaternary ammonium salts, pyridinium salts, and primary to tertiary amino groups, (b) sulfonate groups, sulfate ester bases, phosphate esters Anionic antistatic agents having anionic groups such as bases and phosphonate groups, (c) positive antistatic agents such as amino acid-based and aminosulfate ester-based, (d) nonionic charging such as amino alcohol-based, glycerin-based, and polyethylene glycol-based An antistatic agent, (e) a polymer antistatic agent having a high molecular weight of the antistatic agent as described above, and the like are disclosed (Patent Document 4).

However, in the surface protective film described in Patent Document 4, although there is a description regarding the provision of antistatic performance related to adhesion of dust to an adherend, a solution means for achieving both excellent adhesion performance and contamination resistance is not described. It remains as a further problem to be solved.

In addition, in recent years, it has been proposed to include an antistatic agent in the base film or directly in the pressure-sensitive adhesive layer without applying it to the surface of the base film. For example, an antistatic pressure-sensitive adhesive composition is disclosed, wherein a salt having an anion having a fluoro group and a sulfonyl group is dispersed in a polyether ester-based plasticizer containing a polyether group in the main chain. (Patent Document 5).

In the pressure-sensitive adhesive composition described in Patent Document 5, an ester formed of a mono or dicarboxylic acid having a saturated or unsaturated acyclic hydrocarbon group and an alcohol having an acyclic hydrocarbon group having 1 to 20 carbon atoms as a plasticizer, or the unsaturated acyclic hydrocarbon It has been disclosed to use plasticizers consisting of an epoxidized ester of unsaturated groups in the group. The mono or dicarboxylic acid having such a saturated or unsaturated acyclic hydrocarbon group has a carbon number close to the carbon number of the acrylic monomer constituting the acrylic copolymer used in the pressure-sensitive adhesive layer, thereby improving compatibility with the antistatic adhesive composition, Bleed-out is suppressed because it is preferably retained in the plasticizer acrylic antistatic adhesive composition.

However, in the pressure-sensitive adhesive layer in which the antistatic pressure-sensitive adhesive composition described in Patent Document 5 is crosslinked, antistatic performance and bleed-out improvement techniques are disclosed, but excellent adhesion performance is achieved by having a balance of adhesion in low-speed peeling speed and high-speed peeling speed. There is no description of what is obtained, and a problem remains that an adhesive layer having excellent adhesive performance is obtained.

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

As described above, as the required performance for the pressure-sensitive adhesive layer constituting the surface protection film, (1) having a balance of adhesive strength at low-speed peeling speed and high-speed peeling speed, (2) having stain resistance, (3) No prior art has been identified which solves the problem of simultaneously achieving what has excellent antistatic performance.

In addition, the relationship between the antistatic performance of the pressure-sensitive adhesive layer formed using the pressure-sensitive adhesive composition having antistatic performance and the surface protection film using the same and the anti-pollution performance of the adherend is a trade-off relationship, and maintains antistatic performance. It was difficult to improve the anti-pollution performance with one.

In addition, in recent years, since the type of adherend material to which the surface protection film is bonded increases, and the surface treatment state of the adherend is also varied, the pressure-sensitive adhesive layer constituting the surface protection film is particularly suitable for all adherends. It is becoming increasingly difficult to have a balance of adhesion between (1) low-speed peeling speed and high-speed peeling speed, and (2) having fouling resistance.

This invention was made | formed in view of the said situation, and it has the adhesive force balanced in the low-speed peeling speed and the high-speed peeling speed, and the adhesive composition which can achieve the antistatic performance and the pollution-resistant performance, and the adhesive film using the same , It is an object to provide a surface protection film.

The inventors of the present invention reviewed the types of compounds copolymerized with the acrylic polymer of the pressure-sensitive adhesive composition containing an acrylic polymer, an antistatic agent, and a crosslinking agent as the pressure-sensitive adhesive composition used in the surface protective film for polarizing plates. In the peeling speed and the high-speed peeling speed, an improvement was made on the subject of achieving the balance between having a balance of adhesion and (2) having a fouling resistance.

As a result, (A) Among the alkyl (meth) acrylates having C1 to C10 carbon atoms in the alkyl group, 2-ethylhexylacrylate and a monofunctional methacrylate monomer having a glass transition point temperature (Tg) of a homopolymer of 0 ° C or higher. It has been found that the problems of the above (1) and (2) can be solved at the same time by defining the content ratio of to a specific range, and the present invention has been completed by further comprising an adhesive composition containing an antistatic agent.

In order to solve the above problems, the present invention is a pressure-sensitive adhesive composition comprising a first acrylic polymer, a crosslinking agent, and an ionic compound, wherein the first acrylic polymer is (A) an alkyl group having C1 to C10 alkyl (meta A) 100 parts by weight of the total of at least two or more acrylates, (B) a total of at least one or more of the copolymerizable monomer containing a hydroxyl group, and (C) a copolymerizable monomer containing a carboxyl group. It is an acrylic polymer composed of a copolymer having an acid value of 0.1 to 1.0 and a weight average molecular weight of more than 300,000 to 1,000,000, in which 0.01 to 0.6 parts by weight of at least one total is copolymerized, and the carbon number of the (A) alkyl group is C1 to C10. Of 100 parts by weight of at least two or more types of alkyl (meth) acrylates, 2-ethylhexyl acrylate is 50 parts by weight or more, and the homopolymer is a monofunctional methacrylate having a Tg of 0 ° C or more. The pressure-sensitive adhesive composition, which contains a total of one or more acrylate monomers in a proportion of 5 to 40 parts by weight, contains a trifunctional or higher isocyanate compound as the crosslinking agent, a crosslinking retarder, and a crosslinking catalyst other than a tin compound as a crosslinking catalyst. It provides an adhesive composition, characterized in that made.

When the surface protection film formed by laminating the pressure-sensitive adhesive layer cross-linking the pressure-sensitive adhesive composition to a thickness of 15 μm on one side of a polyester film having a thickness of 38 μm is adhered to the surface of the polarizing plate, when the surface protection film is peeled from the polarizing plate, It is preferable that the adhesive force at a low-speed peeling speed of 0.3 m / min is 0.01 to 0.1 N / 25 mm, and the adhesive strength at a high-speed peeling speed of 30 m / min is 1.0 N / 25 mm or less.

The monofunctional methacrylate monomer having a Tg of 0 ° C or higher of the homopolymer is n-butyl methacrylate, isobutyl methacrylate, s-butyl methacrylate, t-butyl methacrylate, n-propyl methacrylate, It is preferable that it is one or more selected from the compound group consisting of isopropyl methacrylate, ethyl methacrylate, and methyl methacrylate.

The pressure-sensitive adhesive composition further comprises a second acrylic polymer, wherein the second acrylic polymer is (a) at least one or more of (meth) acrylic acid ester monomers having C1 to C18 carbon atoms in the alkyl group, and (b) It is a copolymer obtained by copolymerizing at least one or more of a copolymerizable monomer containing a hydroxyl group, and at least one or more of (c) a polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer, and the pressure-sensitive adhesive composition is (A). It is preferable that the second acrylic polymer is contained in a proportion of 0.1 to 5.0 parts by weight based on 100 parts by weight of at least two or more types of alkyl (meth) acrylates having C1 to C10 carbon atoms in the alkyl group.

The pressure-sensitive adhesive composition is an pressure-sensitive adhesive composition for forming an pressure-sensitive adhesive layer used in the surface protection film for a polarizing plate, the polarizer protective layer of the polarizing plate is one type selected from the group consisting of TAC-based film, PMMA-based film, PET-based film, , It is preferable that the surface treatment performed on the surface of the polarizer protective layer of the polarizing plate is one selected from the group consisting of untreated, AG treated, LR treated, AR treated, AG-LR treated, and AG-AR treated.

The ionic compound is an ionic compound having a melting point of 25 to 80 ° C, the cation of the ionic compound is pyridinium, and the pressure-sensitive adhesive composition contains 0.01 to 0.01 parts of the ionic compound relative to 100 parts by weight of the first acrylic polymer. It is preferable to contain it as an essential component in a proportion of 10 parts by weight.

The surface resistivity of the pressure-sensitive adhesive layer crosslinked with the pressure-sensitive adhesive composition is 1.0 × 10 ⁺¹² Ω / □ or less,

The peeling voltage of the pressure-sensitive adhesive layer to the low-refractive-index layer formed using the composition for forming a low-refractive-index layer containing a fluorine compound is in the range of +0.3 to −0.3 kV,

The surface substrate is one selected from the group consisting of a TAC-based film, a PMMA-based film, and a PET-based film, and the surface treatment applied to the surface of the surface substrate is untreated, AG treated, LR treated, AR treated, AG- After being attached to a polarizing plate, which is one type selected from the group consisting of LR treatment and AG-AR treatment, it is left for 2 days under an atmosphere of 60 ° C and 90% RH of humidity, and then taken out after 1 day, there is no contamination when peeled desirable.

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

(C) The copolymerizable monomer containing a carboxyl group is (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 It is preferable that at least one or more compounds selected from the group consisting of caprolactone mono (meth) acrylate and 2- (meth) acryloyloxyethyltetrahydrophthalic acid.

The crosslinking retarder is a ketoenol tautomer compound, and the crosslinking retarder is contained in an amount of 0.1 to 300 parts by weight based on 100 parts by weight of the first acrylic polymer, and the crosslinking catalyst is an aluminum chelate compound, titanium At least one metal chelating compound selected from the group consisting of chelating compounds and iron chelating compounds, wherein the crosslinking catalyst is contained in a proportion of 0.001 to 0.5 parts by weight based on 100 parts by weight of the first acrylic polymer, and the crosslinking is delayed. It is preferable that the weight ratio of the agent / crosslinking catalyst is 80 to 1000.

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

The second acrylic polymer is (a) at least one or more of (b) a copolymerizable monomer containing a hydroxyl group, relative to 100 parts by weight of at least one or more of (meth) acrylic acid ester monomers having C1 to C18 alkyl groups. A copolymer having a total weight of 2.0 to 12.0 parts by weight and (c) a polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer in a total weight of 1 to 30 parts by weight of 1 to 30 parts by weight. A value (B-1) of at least one or more total weight parts of the copolymerizable monomer containing the hydroxyl group (B) contained in the first acrylic polymer with respect to 100 parts by weight of the total amount of the first acrylic polymer; At least one or more copolymerizable monomers containing the hydroxyl group (b) contained in the second acrylic polymer relative to 100 parts by weight of the total of the second acrylic polymer. Ratio (b-1) / (B-1) of the total parts by weight of a value (b-1) is preferably in the range of 1.0 to 2.0.

The polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer has an average number of repetitions of alkylene oxides constituting the polyalkylene glycol chain of 3 to 14, and the polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer The diester content is 0.2% or less, and the polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomers include polyalkylene glycol mono (meth) acrylate, methoxypolyalkylene glycol (meth) acrylate, and ethoxypolyalkyl It is preferable that at least one selected from the group consisting of renglycol (meth) acrylate is contained in a proportion of 1 to 50 parts by weight out of 100 parts by weight of the second acrylic polymer.

In addition, the present invention provides a pressure-sensitive adhesive film, characterized in that a pressure-sensitive adhesive layer cross-linking the pressure-sensitive adhesive composition is laminated on one side of the resin film.

In addition, the present invention provides a surface protection film using the adhesive film.

In addition, the present invention provides a surface protection film for a polarizing plate using the adhesive film.

In addition, the present invention provides an optical film having a pressure-sensitive adhesive layer in which the pressure-sensitive adhesive layer cross-linking the pressure-sensitive adhesive composition is laminated on at least one side of the optical film.

In addition, the present invention provides an anti-static treatment and an anti-fouling treatment on an opposite surface to the side on which the pressure-sensitive adhesive layer is formed on one side of the resin film.

In the pressure-sensitive adhesive composition according to the present invention, the first acrylic polymer is 50 parts by weight of 2-ethylhexyl acrylate in 100 parts by weight of at least two or more of alkyl (meth) acrylates having (C) C10 to C10 alkyl groups. The sum of at least one part and one or more of the monofunctional methacrylate monomer having a Tg of the homopolymer of 0 ° C or higher is contained in a proportion of 5 to 40 parts by weight. Thereby, especially in the surface protection film for polarizing plates based on PMMA, it is compatible with (1) having the balance of adhesive force at low-speed peeling speed and high-speed peeling speed, and (2) having anti-pollution performance. .

On the other hand, in the pressure-sensitive adhesive composition according to the present invention, the Tg of the homopolymer containing one or more of a monofunctional methacrylate monomer having a temperature of 0 ° C or higher is (1) balance of adhesion in low-speed peeling speed and high-speed peeling speed. It is not clear why it contributes to having what it has and (2) having what has anti-pollution performance. For conceivable reasons, these methacrylate monomers have a polar functional group such as a carboxyl group or an amide group, or a long chain alkyl group exceeding C10, and thus a polymer having a high Tg is obtained, so that adhesion performance in a crosslinked state is greatly improved. It can be estimated that the improvement is possible, and the affinity of methyl methacrylate, which is the main component of the PMMA-based film, is improved.

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

The pressure-sensitive adhesive composition of the present embodiment is an pressure-sensitive adhesive composition comprising an acrylic polymer, a crosslinking agent, and an ionic compound, wherein the acrylic polymer

(A) 100 parts by weight of the total of at least two or more types of alkyl (meth) acrylates having C1 to C10 carbon atoms in the alkyl group,

(B) 1.0 to 6.0 parts by weight of the sum of at least one or more types of copolymerizable monomers containing hydroxyl groups,

(C) 0.01 to 0.6 parts by weight of the sum of at least one or more types of copolymerizable monomers containing a carboxyl group

Is an acrylic polymer composed of a copolymer having an acid value of 0.1 to 1.0 and a weight average molecular weight of more than 300,000 to 1,000,000,

Of 100 parts by weight of at least two or more of the alkyl (meth) acrylates having C1 to C10 carbon atoms in the alkyl group (A), 50 parts by weight or more of 2-ethylhexyl acrylate and Tg of the homopolymer being 0 ° C or more It comprises a total of one or more monofunctional methacrylate monomers in a proportion of 5 to 40 parts by weight,

It is characterized in that the pressure-sensitive adhesive composition contains a trifunctional or higher isocyanate compound as the crosslinking agent, a crosslinking retarder, and a crosslinking catalyst other than a tin compound as a crosslinking catalyst.

The acrylic polymer used in the pressure-sensitive adhesive composition of the present embodiment is the main polymer of the pressure-sensitive adhesive composition, and may be referred to as a first acrylic polymer when distinguished from the second acrylic polymer described later. The first acrylic polymer is an acrylic polymer having a glass transition point temperature (Tg) of 0 ° C or less. Further, the first acrylic polymer is preferably a copolymer containing (A) an alkyl (meth) acrylate having a C1 to C10 alkyl group as a main component.

(A) As the alkyl (meth) acrylate having C1 to C10 carbon atoms in the alkyl group, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (Meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) Acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, and the like. The alkyl group of these alkyl (meth) acrylates may be any of acyclic (straight, branched) and cyclic (monocyclic, polycyclic).

The first acrylic polymer is a total of 100 parts by weight of (A), 2-ethylhexyl acrylate of 50 parts by weight or more, and the homopolymer Tg is 0 ° C or more of a monofunctional methacrylate monomer total of one or more. It is preferable to contain it in a proportion of 5 to 40 parts by weight.

In addition, 2-ethylhexyl acrylate is preferably contained in a proportion of 50 parts by weight or more, more preferably in a proportion of 60 parts by weight or more, and more than 70 parts by weight of 100 parts by weight of the total (A). It is particularly preferable to contain.

In addition, among the alkyl (meth) acrylates having C1 to C10 carbon atoms in the alkyl group (A), n-butyl methacrylate, isobutyl methacrylate, and s-butyl are monofunctional methacrylate monomers having a Tg of 0 ° C or higher. Methacrylate, t-butylmethacrylate, n-propylmethacrylate, isopropylmethacrylate, ethylmethacrylate, methylmethacrylate, n-pentylmethacrylate, isopentylmethacrylate, n-hexyl And one or more selected from the compound group consisting of methacrylate, isohexyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, and dicyclopentamethacrylate. Among these monofunctional methacrylate monomers having a Tg of 0 ° C or higher, methacrylate monomers having C1 to C6 carbon atoms of the alkyl group are preferable, methacrylate monomers having C1 to C4 carbon atoms of the alkyl group are more preferable, and n-butyl From the group consisting of methacrylate, isobutyl methacrylate, s-butyl methacrylate, t-butyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, ethyl methacrylate, methyl methacrylate Particularly preferred is one or more selected.

The total of one or more monofunctional methacrylate monomers having a Tg of 0 ° C or higher is preferably contained in a proportion of 5 to 40 parts by weight, out of 100 parts by weight of (A) above, and in a proportion of 8 to 40 parts by weight. It is more preferable to contain it, and it is especially preferable to contain it in a ratio of 10 to 35 parts by weight. On the other hand, in the following description, when the monomer is simply referred to as Tg, the Tg of the homopolymer may be indicated.

The copolymerizable monomer containing a hydroxyl group (B) used in the first acrylic polymer is 8-hydroxyoctyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and 4-hydroxybutyl (meth) A group of compounds consisting of acrylate, 2-hydroxyethyl (meth) acrylate, N-hydroxy (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, etc. It is preferable that it is at least one or more selected from.

It is preferable that the first acrylic polymer contains a total of at least one or more types of copolymerizable monomers containing (B) hydroxyl groups in a proportion of 1.0 to 6.0 parts by weight based on 100 parts by weight of (A), and 2.0 It is more preferable to contain it at a ratio of -6.0 parts by weight, and it is particularly preferable to contain it at a rate of 2.5 to 5.5 parts by weight.

The copolymerizable monomer containing a (C) carboxyl group used in the first acrylic polymer is (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, 2- (meth) acryloyloxy Ethyl hexahydrophthalic acid, 2- (meth) acryloyloxypropyl hexahydrophthalic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) acryloyloxyethylsuccinic acid, 2- (meth) acrylo It is preferable that it is at least 1 sort (s) or more selected from the compound group which consists of monooxyethyl maleic acid, carboxy polycaprolactone mono (meth) acrylate, 2- (meth) acryloyloxyethyl tetrahydrophthalic acid, etc.

It is preferable that the first acrylic polymer contains (C) a total of at least one of copolymerizable monomers containing a carboxyl group in a proportion of 0.01 to 0.6 parts by weight, based on 100 parts by weight of (A), and 0.01. It is more preferable to contain it at a ratio of -0.5 parts by weight, and it is particularly preferable to contain it at a rate of 0.01 to 0.4 parts by weight.

The manufacturing method of the said 1st acrylic polymer is not specifically limited, A well-known polymerization method, such as solution polymerization method and emulsion polymerization method, can be used suitably. It is preferable that the first acrylic polymer has a weight average molecular weight of more than 300,000 and less than 1 million. Moreover, it is preferable that the acid value of the said 1st acrylic polymer is 0.1-1.0. Thereby, the fouling resistance performance can be improved. 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 composition according to the present embodiment contains (G) an antistatic agent. It is preferable that the antistatic agent (G) of the present embodiment is an ionic compound having a melting point of 25 to 80 ° C. It is preferable that the ionic compound is a solid at room temperature. The normal temperature is, for example, a temperature of less than 25 ° C, and specifically, it is preferably a solid ionic compound at 23 ° C. It is preferable that the pressure-sensitive adhesive composition according to the present embodiment contains the ionic compound as an essential component in a proportion of 0.01 to 10 parts by weight based on 100 parts by weight of the first acrylic polymer.

The ionic compound the anion include hexafluorophosphate phosphate (PF ₆ ^-), thiocyanate (SCN ^-), perchlorate (ClO ₄ ^-), ₄ fluoride borate (BF ₄ ^-) inorganic anion, a carboxylic acid salt, such as ( RCOO ^-), sulfonate (RSO ₃ ^-), the alkoxide or phenoxide salt (RO ^-), organic already deuyeom (R ₂ N ^-), methide salts (R ₃ C ^-), an organic borate salt (R ₄ B ^And organic anions such as-). R contained in each chemical formula of an organic anion is an organic group which may have fluorine substitution. Examples of the organic group include at least one of alkyl groups, alkoxy groups, aromatic groups (aryl groups, aralkyl groups, etc.), aliphatic or aromatic carbonyl groups, and aliphatic or aromatic sulfonyl groups. The organic group contained in the anion may be partially or completely substituted with one or more halogen atoms such as fluorine atoms.

As the cation of the ionic compound, pyridinium, imidazolium, phosphonium, sulfonium, pyrrolidinium, guanidinium, ammonium, isouronium, thiuronium, piperidinium, pyrazolium, methylium, mor And one selected from the group consisting of polynium. It is preferable that the cation of the ionic compound is pyridinium. The organic group contained in the cation may be partially or entirely substituted with one or more halogen atoms such as fluorine atoms.

When the anion and / or cation of the ionic compound contains an organic group such as an alkyl group, an ionic compound having a melting point of 25 to 80 ° C can be obtained by selecting the chain length of the alkyl group, the position and number of substituents, and the like.

As specific examples of the ionic compound, for example, 1-octylpyridinium hexafluorophosphate, 1-nonylpyridinium hexafluorophosphate, 2-methyl-1-dodecylpyridinium hexafluorophosphate, 3-methyl-1 -Dodecylpyridinium hexafluorophosphate, 1-octylpyridinium dodecylbenzenesulfonate, 1-dodecylpyridinium thiocyanate, 1-dodecylpyridinium dodecylbenzenesulfonate, 4-methyl-1-octylpyri Dinium hexafluorophosphate, 1-nonylpyridinium 2-iodinebenzenesulfonate, 4,5-diiodine-1-butyl-3-methylimidazolium hexafluorophosphate, 2-methyl-1-dodecylpyridinium 2- Iodinebenzenesulfonate, 4,5-diiodine-1-butyl-3-methylimidazolium 3-iodinebenzenesulfonate, 1-octyl-2-methylpyridinium trifluoromethanesulfonate salt, 1,2, 3-trimethylimidazolium pentafluoroethanesulfonate salt, 1-butyl-2,3-dimethylimidazolium trifluoromethanesulfonate salt, 1-hexyl-4-methylpyridinium pentafluoroethanesulfone Salt, 1-octyl-3-methylpyridinium trifluoromethanesulfonate salt, n-octylpyridinium trifluoromethanesulfonate salt, 1-propyl-3-methylpyridinium nonafluorobutanesulfonate salt, 3 -Methyl-1-octylpyridinium nonafluorobutanesulfonate salt, methyltrioctylammonium tris (pentafluorobenzenesulfonyl) methide salt, 1-ethyl-3-methylimidazolium tetrakispentafluorophenyl borate Salt, 1-butyl-1-methylpiperidinium bis (pentafluorobenzenesulfonyl) imide salt, and the like.

The pressure-sensitive adhesive composition according to the present embodiment further contains a trifunctional or higher isocyanate compound (D) as a crosslinking agent. Examples of the trifunctional or higher isocyanate compound include, for example, a burette-modified product of diisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, and xylylene diisocyanate, or isocyanurate modified product. And adducts with trivalent or higher polyols such as trimethylolpropane and glycerin. (D) The proportion of the trifunctional or higher isocyanate compound that is a crosslinking agent is preferably contained in a proportion of 0.1 to 10 parts by weight, for example, based on 100 parts by weight of the first acrylic polymer, and contained in a proportion of 0.1 to 6 parts by weight It is more preferable to do.

The pressure-sensitive adhesive composition according to the present embodiment may contain (E) a crosslinking retarder. (E) As a crosslinking retarder, β-ketoesters such as methyl acetoacetate, ethyl acetoacetate, octyl acetoacetate, oleyl acetoacetate, lauryl acetoacetate, and stearyl acetoacetate, acetylacetone, 2,4-hexanedione , Β-diketones such as benzoyl acetone. These are ketoenol tautomeric compounds, and in the pressure-sensitive adhesive composition comprising a polyisocyanate compound as a crosslinking agent, (D) blocking the isocyanate group possessed by the crosslinking agent suppresses excessive viscosity rise and gelation of the pressure-sensitive adhesive composition after the crosslinking agent is blended. The pot life of the composition can be extended. (E) It is preferable that the crosslinking retarder is at least one or more selected from the group consisting of acetylacetone and ethyl acetoacetate. It is preferable to contain (E) the crosslinking retarder in a ratio of 0.1 to 300 parts by weight with respect to 100 parts by weight of the first acrylic polymer.

The pressure-sensitive adhesive composition according to the present embodiment may contain a crosslinking catalyst other than the tin compound as the crosslinking catalyst (F). (F) The crosslinking catalyst may be a substance that functions as a catalyst for the reaction (crosslinking reaction) between the acrylic polymer and the crosslinking agent when the polyisocyanate compound is used as a crosslinking agent. (F) As a crosslinking catalyst, a metal chelate compound is preferable. 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. 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.

(F) The crosslinking catalyst is preferably an aluminum chelate compound, a titanium chelate compound, or at least one metal chelate compound selected from the group consisting of iron chelate compounds. It is preferable to contain (F) the crosslinking catalyst in a proportion of 0.001 to 0.5 parts by weight based on 100 parts by weight of the first acrylic polymer.

(E) Since the crosslinking retarder has an effect of inhibiting crosslinking as opposed to the (F) crosslinking catalyst, it is preferable to appropriately set the ratio of the (E) crosslinking retarder and (F) crosslinking catalyst. In order to lengthen the pot life of the pressure-sensitive adhesive composition and improve storage stability, the ratio by weight of (E) / (F) is preferably 80 to 1000, more preferably 80 to 700, and 80 to 300 Especially preferred. Here, the ratio of parts by weight of (E) / (F) is the value of the quotient obtained by dividing the part by weight of (E) by the part by weight of (F).

The pressure-sensitive adhesive composition according to the present embodiment may contain (H) a polyether-modified siloxane compound as an optional component. (H) The polyether-modified siloxane compound is a siloxane compound having a polyether group, and in addition to the usual 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 ]. In the siloxane unit having a polyether group, the terminal of the polyether group may be an OH group (R ⁴ = H in the above formula).

(H) It is preferable that the polyether-modified siloxane compound is a polyether-modified siloxane compound having an HLB value of 6 to 12. Further, with respect to 100 parts by weight of the first acrylic polymer, (H) the polyether-modified siloxane compound is preferably contained in a proportion of 0.01 to 0.5 parts by weight, more preferably 0.02 to 0.35 parts by weight, It is particularly preferable to contain it in a proportion of 0.02 to 0.25 parts by weight. The HLB value is, for example, a hydrophilic lipophilic balance (hydrophilic lipophilic ratio) specified in JIS K3211 (a surfactant term).

The polyether-modified siloxane compound can be obtained, for example, by grafting an organic compound having an unsaturated bond and a polyoxyalkylene group to a polyorganosiloxane main chain having a 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.

(H) By mixing the polyether-modified siloxane compound with the pressure-sensitive adhesive composition, the pressure-sensitive adhesive layer and the rework performance of the pressure-sensitive adhesive layer can be improved. (H) The weight average molecular weight of the polyether-modified siloxane compound is preferably 10000 or less. From the viewpoint of compatibility with the acrylic polymer, the HLB value is low and the molecular weight is lower, the compatibility is good. However, if the polyether-modified siloxane compound has a low molecular weight, the HLB value is relatively high, and the antistatic property is excellent even if the compatibility with the polymer is slightly low. This is obtained.

The pressure-sensitive adhesive composition according to the present embodiment may contain a second acrylic polymer as an optional component. The pressure-sensitive adhesive composition further contains a second acrylic polymer copolymerized with a polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer, thereby improving the compatibility between the ionic compound and the acrylic polymer, antistatic performance and fouling resistance performance. Can be further improved. Examples of the second acrylic polymer include (a) at least one or more of (meth) acrylic acid ester monomers having C1 to C18 alkyl groups, (b) at least one or more copolymerizable monomers containing hydroxyl groups, and (c) And copolymers obtained by copolymerizing at least one or more of polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomers.

Examples of the (meth) acrylic acid ester monomer having a carbon number of C1 to C18 of the alkyl group (a) used in the second acrylic polymer are methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, Isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, Hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) ) Acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate , Hexadecyl (meth) acrylate , And the like heptadecyl (meth) acrylate, octadecyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate. The alkyl group of (a) may be either acyclic (straight chain, branched) or cyclic (monocyclic, polycyclic).

The (a) alkyl (C) to C18 (meth) acrylic acid ester monomer used in the second acrylic polymer is (A) an alkyl (C) to C10 alkyl (meth) acrylic having an alkyl group used in the first acrylic polymer. It is also possible to select the same compound or ratio as the rate.

Alternatively, (a) may contain a compound different from (A). Moreover, the ratio in (a) may differ from the ratio in (A) also as a compound with the same monomer. For example, the second acrylic polymer may be a copolymer in which an alkyl methacrylate is not copolymerized. Further, the second acrylic polymer may be a copolymer in which the alkyl group has a C11 to C18 (meth) acrylic acid ester monomer copolymerized, or the second acrylic polymer has a C11 to C18 (meth) acrylic acid alkyl group. You may contain an ester monomer.

The (b) copolymerizable monomer containing a hydroxyl group used in the second acrylic polymer is 8-hydroxyoctyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 4-hydroxybutyl (meth) A group of compounds consisting of acrylate, 2-hydroxyethyl (meth) acrylate, N-hydroxy (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, etc. It is preferable that it is at least one or more selected from.

The second acrylic polymer is (a) at least one type of a copolymerizable monomer containing a hydroxyl group, with respect to 100 parts by weight of at least one or more of the (meth) acrylic acid ester monomers having C1 to C18 carbon atoms in the alkyl group. It is preferable to contain the above total in a ratio of 2.0 to 12.0 parts by weight, more preferably 3.0 to 12.0 parts by weight, and particularly preferably 4.0 to 12.0 parts by weight.

It is also possible to select the same compound or proportion as the (b) copolymerizable monomer containing a hydroxyl group used in the second acrylic polymer, and the (B) copolymerizable monomer containing a hydroxyl group used in the first acrylic polymer. Alternatively, (b) may contain a compound different from (B). Moreover, even if the monomer is the same compound, the ratio in (b) may be different from the ratio in (B).

The second acrylic polymer used in the pressure-sensitive adhesive composition of the present embodiment contains (c) a polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer. In the pressure-sensitive adhesive composition of the present embodiment, the (c) second acrylic polymer containing a polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer functions as an antistatic auxiliary agent.

Meanwhile, the first acrylic polymer may be a copolymer without copolymerizing a polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer, or the same polyalkylene glycol chain-containing mono (meth) acrylic acid ester as the second acrylic polymer. It is also possible to copolymerize the monomers.

The second acrylic polymer is contained in a proportion of 0.1 to 5.0 parts by weight based on 100 parts by weight of a total of at least two or more types of alkyl (meth) acrylates having C1 to C10 alkyl groups (A) used in the first acrylic polymer. It is preferable, and it is more preferably contained in a proportion of 0.1 to 3.5 parts by weight, particularly preferably 0.1 to 2.5 parts by weight.

(c) As a mono (meth) acrylic acid ester monomer containing a polyalkylene glycol chain, a compound in which one hydroxyl group among a plurality of hydroxyl groups of the polyalkylene glycol is esterified as a (meth) acrylic acid ester may be sufficient. Since the (meth) acrylic acid ester group becomes a polymerizable group, it can be copolymerized with the second acrylic polymer. Another hydroxyl group may be a polyalkylene glycol mono (meth) acrylate with OH intact, or an alkoxy polyalkylene glycol mono (meth) acrylate in which another hydroxyl group has been converted to an alkyl ether. On the other hand, since polyalkylene glycol mono (meth) acrylate corresponds to (c), even if it contains a hydroxyl group, it is not classified as (B) or (b).

The polyalkylene glycol constituting the polyalkylene glycol chain may be a glycol compound having one or two or more alkylene groups, for example, polyethylene glycol, polypropylene glycol, polybutylene glycol, polyethylene glycol-polypropylene And glycols, polyethylene glycol-polybutylene glycol, polypropylene glycol-polybutylene glycol, polyethylene glycol-polypropylene glycol-polybutylene glycol, and the like.

(c) The polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer preferably has an average repetition number of 3 to 14 alkylene oxides constituting the polyalkylene glycol chain. The "average number of repeats of alkylene oxide" means that the alkylene oxide unit repeats in the "polyalkylene glycol chain" portion included in the molecular structure of (c) the polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer. It is the average number.

Moreover, it is preferable that the diester content in the (c) polyalkylene glycol chain containing mono (meth) acrylic acid ester monomer is 0.2% or less. The "diester content in a monomer" is the content rate (weight%) of the polyalkylene glycol di (meth) acrylic acid ester contained in (c) the polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer.

(c) Polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomers include polyalkylene glycol mono (meth) acrylate, methoxy polyalkylene glycol (meth) acrylate, and ethoxy polyalkylene glycol (meth) It is preferable that it is at least 1 sort (s) or more selected from the group which consists of acrylates.

The second acrylic polymer is (a) a total of 100 parts by weight of at least one or more of (meth) acrylic acid ester monomers having a C1 to C18 carbon number of the alkyl group, (c) mono (meth) acrylic acid containing a polyalkylene glycol chain It is preferred to contain the ester monomer in a proportion of 1 to 30 parts by weight, more preferably 2 to 30 parts by weight, and particularly preferably 5 to 25 parts by weight.

The manufacturing method of the said 2nd acrylic polymer is not specifically limited, A well-known polymerization method, such as solution polymerization method and emulsion polymerization method, can be used suitably. The second acrylic polymer is preferably a copolymer having a weight average molecular weight of more than 300,000 to 800,000 or less. The weight average molecular weight of the second acrylic polymer may be about the same as the weight average molecular weight of the first acrylic polymer, or may be larger or smaller than the weight average molecular weight of the first acrylic polymer.

The second acrylic polymer may have a functional group capable of reacting with the crosslinking agent (D). The second acrylic polymer may be a copolymer that does not copolymerize a copolymerizable monomer containing a carboxyl group, or it may also copolymerize a copolymerizable monomer containing the same carboxyl group as the first acrylic polymer. (D) The crosslinking agent may be involved in the crosslinking of the first acrylic polymer and the second acrylic polymer.

The value (B-1) of the at least one total weight part of the copolymerizable monomer containing a hydroxyl group contained in the first acrylic polymer relative to 100 parts by weight of the first acrylic polymer (B-1), and the second acrylic polymer Ratio (b-1) / (B-1) of the value (b-1) of at least one total weight part of the copolymerizable monomer containing a hydroxyl group (b) contained in the second acrylic polymer with respect to 100 parts by weight of the total ) Is preferably in the range of 1.0 to 2.0.

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

The pressure-sensitive adhesive composition of the present embodiment is preferred as the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer used in the surface protective film for polarizing plates. The pressure-sensitive adhesive layer of the surface protection film may be bonded to the polarizer protective layer of the polarizing plate. Here, at least one or more selected from the group consisting of a TAC-based film, a PMMA-based film, and a PET-based film may be mentioned. Here, TAC is an abbreviation of triacetyl cellulose, PMMA is polymethyl methacrylate, and PET is polyethylene terephthalate.

Moreover, at least 1 sort (s) or more selected from the group which consists of the unprocessed, AG process, LR process, AR process, AG-LR process, and AG-AR process may be sufficient as the surface treatment performed on the surface of the polarizer protective layer of a polarizing plate. Here, AG is anti-glare, LR is low reflection, and AR is anti-reflection.

In the pressure-sensitive adhesive layer in which the pressure-sensitive adhesive composition of the present embodiment is crosslinked, the surface resistivity of the pressure-sensitive adhesive layer is preferably 1.0 × 10 ⁺¹² Ω / □ or less, more preferably 5.0 × 10 ⁺¹¹ Ω / □ or less, and 1.0 × 10 ⁺¹¹ Ω / □ It is particularly preferable that the following. When the surface resistivity is large, the performance of discharging static electricity generated when the pressure-sensitive adhesive layer is peeled from the adherend becomes poor. For this reason, by sufficiently reducing the surface resistivity, the peeling voltage generated by the static electricity generated when the pressure-sensitive adhesive layer is peeled from the adherend is reduced, so that the influence on the adherend can be suppressed.

In the pressure-sensitive adhesive layer in which the pressure-sensitive adhesive composition of the present embodiment is crosslinked, the peeling voltage of the pressure-sensitive adhesive layer to the low-refractive-index layer formed using the composition for forming a low-refractive-index layer containing a fluorine compound is within the range of +0.3 to -0.3 kV. desirable. Fluorine compounds used in the composition for forming a low-refractive-index layer include fluorine-containing copolymers such as fluorinated olefins, fluorinated vinyl ethers, fluorinated alkyl (meth) acrylates, or fluorinated alkyl group-containing silane compounds. And condensates. In the fluorine-containing copolymer, in addition to the fluorinated monomers, non-fluorinated monomers such as olefins, vinyl ethers, and (meth) acrylates may be copolymerized. The low-refractive-index layer may be combined with a high-refractive-index layer or the like to form an antireflection layer.

When measuring the peeling voltage against the low-refractive-index layer, a substrate for forming the low-refractive-index layer on the surface includes a PMMA substrate and a TAC substrate. Moreover, it is preferable that the peeling voltage of the pressure-sensitive adhesive layer which crosslinked the pressure-sensitive adhesive composition of the present embodiment with respect to the surface of the PMMA substrate and the TAC substrate is +0.3 to -0.3 kV for the plane layer where nothing is treated.

After the pressure-sensitive adhesive layer is adhered to an adherend such as a polarizing plate, it is left for 2 days (48hr) in an atmosphere of 60 ° C temperature and 90% RH humidity, and after taking it out from the atmosphere, there is no contamination when peeled after 1 day. It is preferred. As an adherend, a polarizing plate in which a protective layer is laminated on a polarizer, and the surface of the protective layer is treated with a low-reflection surface with a composition containing a fluorine compound. The composition containing the fluorine compound used for the low-reflection surface treatment may be the same as or different from the resin composition for forming a low-refractive-index layer containing the fluorine compound described above. Examples of the protective layer and the surface treatment include the polarizer protective layer and the surface treatment applied to the surface.

After the surface protection film formed by laminating the pressure-sensitive adhesive layer obtained by crosslinking the pressure-sensitive adhesive composition of the present embodiment to a thickness of 15 μm on one side of a polyester film having a thickness of 38 μm, is adhered to the surface of the polarizing plate, the surface protection film is removed from the polarizing plate. When peeling, the adhesive strength at a low-speed peeling speed of 0.3 m / min is 0.01 to 0.1 N / 25 mm, and the adhesive strength at a high-speed peeling speed of 30 m / min is preferably 1.0 N / 25 mm or less, and the high-speed peeling speed of 30 m / min It is more preferable that the adhesive strength at is 0.2 to 1.0 N / 25 mm. Thereby, the performance with which the adhesive force has little change even by the peeling speed is obtained, and it is possible to peel quickly even by high-speed peeling. Moreover, in order to re-attach, once, when peeling a surface protection film, it is easy to peel from an adherend without requiring excessive force.

The gel fraction of the pressure-sensitive adhesive layer formed by crosslinking the pressure-sensitive adhesive composition of the present embodiment is preferably 95 to 100%, and more preferably 97 to 100%. The high gel fraction of the pressure-sensitive adhesive layer prevents excessive adhesion at low-speed peeling rates, and elution of unpolymerized monomers or oligomers from the copolymer is reduced, improving reworkability and durability at high temperature and high humidity. It can suppress the contamination of the adherend.

The adhesive film of this embodiment is formed by forming the adhesive layer formed by crosslinking the adhesive composition of this embodiment on one side or both sides of the resin film. In addition, the surface protection film of this embodiment is a surface protection film formed by forming the pressure-sensitive adhesive layer formed by crosslinking the pressure-sensitive adhesive composition of the present embodiment on one side of the resin film. The pressure-sensitive adhesive composition of the present embodiment has excellent antistatic performance, excellent balance of adhesion in low-speed peeling speed and high-speed peeling speed, and also has fouling resistance performance. 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 release film (separator) which protects an adhesive surface, resin films, such as a polyester film, etc. can be used.

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

Moreover, the optical film with an adhesive layer can be obtained by laminating | stacking the adhesive layer which bridge | crosslinked the adhesive composition of this embodiment on at least one side of an optical film. Examples of the optical film include a polarizing film, a retardation film, an antireflection film, an anti-glare (anti-glare) film, an ultraviolet absorbing film, an infrared absorbing film, an optical compensation film, and a brightness enhancing film. Examples of the device to which the optical member is applied include liquid crystal panels, organic EL panels, and touch panels.

In the case of an optical surface protective film and an adhesive film, such as a surface protective film for a polarizing plate, it is preferable that a base film and an adhesive layer have sufficient transparency.

Example

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

<Production of the first acrylic polymer>

[Example 1]

Nitrogen gas was introduced into a reaction device 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, a solvent (ethyl acetate) was added to the reaction apparatus together with 70 parts by weight of 2-ethylhexyl acrylate, 30 parts by weight of n-butyl methacrylate, 5.5 parts by weight of 8-hydroxyoctyl acrylate, and 0.2 parts by weight of acrylic acid. did. Thereafter, 0.1 part by weight of azobisisobutyronitrile as a polymerization initiator was added dropwise over 2 hours, and reacted at 65 ° C for 6 hours to obtain a first acrylic polymer used in Example 1.

[Examples 2 to 6 and Comparative Examples 1 to 4]

Examples 2 to 6 and comparison were made in the same manner as in the first acrylic polymer solution used in Example 1, except that the composition of the monomers was as described in (A), (B), and (C) in Table 1, respectively. The first acrylic polymer solutions used in Examples 1 to 4 were obtained.

On the other hand, the first acrylic polymers used in Examples 1 to 6 and Comparative Examples 1 to 4 were copolymers having a weight average molecular weight of more than 300,000 and less than 1 million.

<Production of adhesive composition and surface protection film>

[Example 1]

With respect to the first acrylic polymer solution of Example 1 prepared as above, 2.0 parts by weight of a crosslinking agent (coronate HX), 9 parts by weight of acetylacetone, 0.1 parts by weight of a crosslinking catalyst (titanium trisacetylacetonate), antistatic agent (3 -Methyl-1-octylpyridinium nonafluorobutanesulfonate salt) 0.9 parts by weight, polyether-modified siloxane compound (HLB = 7) 0.05 parts by weight, 2-ethylhexyl acrylate and 8-hydroxyoctyl acrylate and me To the pressure-sensitive adhesive composition of Example 1, 0.2 parts by weight of a copolymer having a weight average molecular weight (Mw) of 600,000 copolymerized with methoxy polyethylene glycol acrylate (n = 8) in a weight ratio of 100: 8: 15 was added and stirred and mixed. After applying this pressure-sensitive adhesive composition on a release film (silicone resin-coated PET film), the solvent was removed by drying at 90 ° C. to obtain a pressure-sensitive adhesive layer having a thickness of 20 μm. Thereafter, the pressure-sensitive adhesive layer having a release film formed on a surface opposite to the antistatic and antifouling treated surface of the base film (an antistatic and antifouling treated PET film on one side) was transferred to the substrate, and the substrate film / adhesive layer / release The surface protection film of Example 1 which has a laminated structure of “film” was obtained.

[Examples 2 to 6 and Comparative Examples 1 to 4]

Examples 2 to 6 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 (D) to (H) and (J) in Tables 1 to 2, respectively. A surface protective film of -4 was obtained.

On the other hand, in the surface protection films of Examples 1 to 6 and Comparative Examples 1 to 4, the gel fractions of the pressure-sensitive adhesive layer were all in the range of 95 to 100%.

In Tables 1 to 2, the weight part of each component was determined by setting the total number of alkyl (meth) acrylates having (C) C10 to C10 alkyl groups as 100 parts by weight.

On the other hand, in Tables 1 to 2, in the columns of (B) to (H) and (J), the acrylic polymer was used as 100 parts by weight, and the content ratio (parts by weight) of each component was shown in numerical values in parentheses ().

In addition, Table 3 shows the compound names of the abbreviations of the components (A) to (H) used in Tables 1 to 2. On the other hand, Coronate (registered trademark) HX, Coronate HL and Coronate L are trade names of Tosoh Corporation, and Takenate (registered trademark) D-140N, D-127N, and D-110N are trade names of Mitsui Chemicals.

(G) Among the antistatic agents, G-1 to G-4 are ionic compounds having a melting point of 25 ° C to 80 ° C and being solid at room temperature. G-5 is an ionic compound having a melting point of more than 80 ° C and being solid at room temperature. In addition, the weight average molecular weight of H-1 to H-6 in (H) polyether-modified siloxane compound is 10000 or less.

In addition, Table 4 shows the composition and molecular weight (Mw) of the monomers constituting the second acrylic polymer shown in column (J) of Table 2. In addition, the compound names of the abbreviations of each component used in Table 4 are shown in Table 5. In Table 4, the weight part of each component was calculated | required as the sum of (a) being 100 weight part. In addition, in each column of (b)-(c), the content ratio (weight part) calculated | required by making the total of 2nd acrylic polymer into 100 weight part was shown by the numerical value in parenthesis ().

(c) Among the mono (meth) acrylic acid ester monomers containing a polyalkylene glycol chain, I-1 to I-3 are monomers having a diester content of 0.2 wt% or less, and I-4 is a monomer having a diester content of 0.8 wt%. The value of n represents the average number of repeats of the alkylene oxide.

<Test method and evaluation>

The surface protective films in Examples 1 to 6 and Comparative Examples 1 to 4 were aged for 7 days in an atmosphere of 23 ° C. and 50% RH humidity, respectively, and then evaluated by the following test methods.

<Testing method for adhesive force>

The release film was peeled off and the surface protection film exposing the pressure-sensitive adhesive layer was pasted onto the surface of the polarizing plate via the pressure-sensitive adhesive layer, left for 1 day, and autoclaved at 50 ° C, 5 atmospheres, and 20 minutes, and additionally 12 hours at room temperature. What was left was used as the measurement sample of adhesive force. The obtained measurement sample was peeled off at a low speed (0.3 m / min) or a high speed (30 m / min) using a tensile tester in the direction of 180 ° to determine the peel strength measured as an adhesive force.

Here, the polarizer protective layer of the polarizing plate is polymethyl methacrylate (PMMA) having an AG-LR treatment layer.

<Test method for surface resistivity>

After aging the surface protection film, the release film was peeled off before sticking to the polarizing plate, and the pressure-sensitive adhesive layer was exposed, and the surface resistivity of the pressure-sensitive adhesive layer was measured using a resistivity meter HighResta UP-HT450 (manufactured by Mitsubishi Chemical Analytics). .

<Test method of peeling high voltage>

The release film was peeled off and the surface protective film on which the pressure-sensitive adhesive layer was exposed was adhered to a polarizing plate having a low-refractive-index layer formed using a composition for forming a low-refractive-index layer containing a fluorine compound on the adherend. When the surface protection film was peeled 180 ° at a tensile speed of 30 m / min, the voltage (high voltage) generated by charging of the adherend was 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.

<Test method for contamination resistance>

A polarizing plate on which one surface of the glass plate was subjected to low-reflection (LR) surface treatment was pasted through an adhesive layer (double-sided adhesive tape) using a bonding machine. Then, the surface protection film was stuck on the surface of the said polarizing plate using the bonding machine. After sticking to the adherend, it is left for 2 days (48hr) in an atmosphere at a temperature of 60 ° C and a humidity of 90% RH, and after taking out from the atmosphere, after 1 day, the surface protective film is peeled off and the surface of the polarizing plate is contaminated The condition was observed with the naked eye. As a criterion for determining the stain resistance, the surface of the polarizing plate was evaluated as "○" when there was no contamination, "△" when there was little contamination, and "X" when there was contamination.

Table 6 shows the evaluation results for the surface protective films in Examples 1 to 6 and Comparative Examples 1 to 4. "Surface resistivity" was expressed according to a method in which "m x 10 ^{+ n} " is "mE + n" (where m is an arbitrary real value and n is a positive integer).

The column of "pollution resistance" indicates the material (TAC, PMMA, PET) and surface treatment (untreated, AG treated, LR treated, AR treated, AG-LR treated) of the polarizer protective layer of the polarizing plate used in the test. Plain of "surface treatment" means untreated.

The surface protective films of Examples 1 to 6 had an adhesive strength at a low-speed peeling rate of 0.3 m / min to a polarizing plate as an adherend of 0.01 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 mm. From the following points, the adhesive performance was excellent by having a balance of adhesive force in the low-speed peeling speed and the high-speed peeling speed.

In addition, in the surface protection films of Examples 1 to 6, the surface resistivity of the pressure-sensitive adhesive layer was 1.0 × 10 ⁺¹² Ω / □ or less, and the pressure-sensitive adhesive layer to the low-refractive-index layer formed using the composition for forming a low-refractive-index layer containing a fluorine compound The peeling large voltage of was within the range of +0.3 to -0.3 kV, and the antistatic performance was excellent.

In addition, the surface protective films of Examples 1 to 6 were adhered to the adherend, left for 48 hr under an atmosphere of 60 ° C. at a temperature of 90% RH, and contaminated with various polarizing plates as adherends even after 1 day after taking out from the atmosphere. Without this, the anti-pollution performance was also excellent.

That is, according to the evaluation results shown in Table 6, it was demonstrated that the surface protection films of Examples 1 to 6 can solve the problems of the present invention.

In the surface protective film of Comparative Example 1 (Tg of the monofunctional methacrylate monomer copolymerized with the first acrylic polymer was less than 0 ° C), the fouling resistance was poor for adherends other than TAC.

In addition, in the surface protection film of Comparative Example 2 (the amount of hydroxyl group-containing monomers copolymerized with the first acrylic polymer was excessive), the adhesion at a low peel rate was large, and the PMMA had poor fouling resistance.

In addition, in the surface protection film of Comparative Example 3 (the first acrylic polymer does not contain a methacrylate monomer having a Tg of 0 ° C or higher, the proportion of carboxyl group-containing monomers is excessive, and the melting point of the antistatic agent exceeds 80 ° C), it is high speed. The adhesive strength at the peeling rate was large, the peeling voltage was high, and the fouling resistance was poor.

In addition, the surface protection film of Comparative Example 4 (in Tables 1 and 2, component (B) of Example 3, except that component (A) of Comparative Example 4 does not contain a methacrylate monomer having a Tg of 0 ° C or higher) (Same as (H) and (J)), compared with the surface protection film of Example 3, the adhesive strength at a high-speed peeling speed was large, the peeling voltage was high, and the PMMA had poor fouling resistance performance.

From the performance comparison of the surface protection film of Comparative Example 4 and the surface protection film of Example 3, in the pressure-sensitive adhesive composition according to the present invention, the homopolymer has a Tg of 0 ° C or higher and contains at least one monofunctional methacrylate monomer. It became clear that this contributes to having (1) having a balance of adhesive force at low-speed peeling speed and high-speed peeling speed, and (2) having anti-pollution performance.

In addition, the problems of the present invention could not be solved in the surface protective films of Comparative Examples 1 to 4 as described above.

Claims (17)

A pressure-sensitive adhesive composition comprising a first acrylic polymer, a crosslinking agent, and an ionic compound,
The first acrylic polymer
(A) 100 parts by weight of the total of at least two or more types of alkyl (meth) acrylates having C1 to C10 carbon atoms in the alkyl group,
(B) 1.0 to 6.0 parts by weight of the sum of at least one or more types of copolymerizable monomers containing hydroxyl groups,
(C) 0.01 to 0.6 parts by weight of the sum of at least one or more types of copolymerizable monomers containing a carboxyl group
Is an acrylic polymer composed of a copolymer having an acid value of 0.1 to 1.0 and a weight average molecular weight of more than 300,000 to 1,000,000,
Of 100 parts by weight of at least two or more of the alkyl (meth) acrylates having C1 to C10 carbon atoms in the alkyl group (A), 50 parts by weight or more of 2-ethylhexyl acrylate and Tg of the homopolymer being 0 ° C or more It comprises a total of one or more monofunctional methacrylate monomers in a proportion of 5 to 40 parts by weight,
The pressure-sensitive adhesive composition, wherein the pressure-sensitive adhesive composition comprises a trifunctional or higher isocyanate compound, a crosslinking retarder, and a crosslinking catalyst other than a tin compound as a crosslinking catalyst. According to claim 1,
When the surface protection film formed by laminating the pressure-sensitive adhesive layer crosslinked with the pressure-sensitive adhesive composition to a thickness of 15 μm on one side of a polyester film having a thickness of 38 μm is adhered to the surface of the polarizing plate, and when the surface protection film is peeled from the polarizing plate Pressure-sensitive adhesive composition at a low-speed peeling rate of 0.3 m / min is 0.01 to 0.1 N / 25 mm, and the adhesive strength at a high-speed peeling speed of 30 m / min is 1.0 N / 25 mm or less. The method of claim 1 or 2,
The monofunctional methacrylate monomer having a Tg of 0 ° C or higher of the homopolymer is n-butyl methacrylate, isobutyl methacrylate, s-butyl methacrylate, t-butyl methacrylate, n-propyl methacrylate, The pressure-sensitive adhesive composition, characterized in that at least one member selected from the group consisting of isopropyl methacrylate, ethyl methacrylate, and methyl methacrylate. The method of claim 1 or 2,
The pressure-sensitive adhesive composition is further made by containing a second acrylic polymer,
The second acrylic polymer
(a) at least one or more of (meth) acrylic acid ester monomers having C1 to C18 carbon atoms in the alkyl group,
(b) at least one copolymerizable monomer containing a hydroxyl group, and
(c) a copolymer obtained by copolymerizing at least one of poly (alkylene glycol) -containing mono (meth) acrylic acid ester monomers,
The pressure-sensitive adhesive composition containing the second acrylic polymer in a proportion of 0.1 to 5.0 parts by weight based on 100 parts by weight of at least two or more kinds of alkyl (meth) acrylates having C1 to C10 carbon atoms in the alkyl group (A). Characterized in that the pressure-sensitive adhesive composition. The method of claim 1 or 2,
The pressure-sensitive adhesive composition is an pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer used in the surface protective film for a polarizing plate,
The polarizer protective layer of the polarizing plate is one selected from the group consisting of a TAC-based film, a PMMA-based film, and a PET-based film, and the surface treatment applied to the surface of the polarizer protective layer of the polarizing plate is untreated, AG treated, LR Adhesive composition characterized in that it is one kind selected from the group consisting of treatment, AR treatment, AG-LR treatment, and AG-AR treatment. The method of claim 1 or 2,
The ionic compound is an ionic compound having a melting point of 25 to 80 ° C,
The cation of the ionic compound is pyridinium,
The pressure-sensitive adhesive composition, characterized in that the pressure-sensitive adhesive composition is made to contain the ionic compound in an amount of 0.01 to 10 parts by weight relative to 100 parts by weight of the first acrylic polymer. The method of claim 1 or 2,
The surface resistivity of the pressure-sensitive adhesive layer crosslinked with the pressure-sensitive adhesive composition is 1.0 × 10 ⁺¹² Ω / □ or less,
The peeling voltage of the pressure-sensitive adhesive layer to the low-refractive-index layer formed using the composition for forming a low-refractive-index layer containing a fluorine compound is in the range of +0.3 to -0.3 kV,
The surface substrate is one selected from the group consisting of TAC-based films, PMMA-based films, and PET-based films, and the surface treatment applied to the surface of the surface-based substrate is untreated, AG treated, LR treated, AR treated, AG- After being bonded to a polarizing plate of one type selected from the group consisting of LR treatment and AG-AR treatment, the product was left for 2 days in an atmosphere at a temperature of 60 ° C and a humidity of 90% RH, and then taken out. Characterized in that the pressure-sensitive adhesive composition. The method of claim 1 or 2,
The (B) copolymerizable monomer containing a hydroxyl group is 8-hydroxyoctyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxyethyl At least one member selected from the group consisting of (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 pressure-sensitive adhesive composition, characterized in that at least one member selected from the group consisting of caprolactone mono (meth) acrylate and 2- (meth) acryloyloxyethyltetrahydrophthalic acid. The method of claim 1 or 2,
The crosslinking retarder is a ketoenol tautomer compound,
It is made by containing the crosslinking retarder in a proportion of 0.1 to 300 parts by weight with respect to 100 parts by weight of the first acrylic polymer,
The crosslinking catalyst is at least one metal chelate compound selected from the group consisting of aluminum chelate compounds, titanium chelate compounds, and iron chelate compounds,
It is made by containing the crosslinking catalyst in a proportion of 0.001 to 0.5 parts by weight based on 100 parts by weight of the first acrylic polymer,
The pressure-sensitive adhesive composition, characterized in that the weight ratio of the crosslinking retarder / the crosslinking catalyst is 80 to 1000. The method of claim 1 or 2,
The pressure-sensitive adhesive composition, wherein the pressure-sensitive adhesive composition comprises a polyether-modified siloxane compound having an HLB value of 6 to 12 and a weight-average molecular weight of 10000 or less in a proportion of 0.01 to 0.5 parts by weight based on 100 parts by weight of the first acrylic polymer. . The method of claim 4,
The second acrylic polymer
(a) 100 parts by weight of the total of at least one or more of (meth) acrylic acid ester monomers having C1 to C18 carbon atoms in the alkyl group,
(b) 2.0 to 12.0 parts by weight of the sum of at least one or more types of copolymerizable monomers containing hydroxyl groups,
(c) is a copolymer having a weight average molecular weight of more than 300,000 to 800,000 or less by copolymerizing 1 to 30 parts by weight of a total of at least one of a poly (alkylene glycol) -containing mono (meth) acrylic acid ester monomer,
The value (B-1) of the at least one or more total weight parts of the copolymerizable monomer containing the hydroxyl group (B) contained in the first acrylic polymer relative to 100 parts by weight of the first acrylic polymer, and the second Ratio (b-1) of the value (b-1) of at least one total weight part of the copolymerizable monomer containing the hydroxyl group (b) contained in the second acrylic polymer to 100 parts by weight of the acrylic polymer (b-1) / (B-1) The adhesive composition characterized by being in the range of 1.0 to 2.0. The method of claim 4,
The polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer has an average number of repetitions of alkylene oxides constituting the polyalkylene glycol chain of 3 to 14,
The diester content in the mono (meth) acrylic acid ester monomer containing the polyalkylene glycol chain is 0.2% or less,
The polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomers include polyalkylene glycol mono (meth) acrylate, methoxy polyalkylene glycol (meth) acrylate, and ethoxy polyalkylene glycol (meth) acrylate. An adhesive composition comprising at least one selected from the group consisting of 1 to 50 parts by weight of 100 parts by weight of the second acrylic polymer. An adhesive film comprising a pressure-sensitive adhesive layer obtained by crosslinking the pressure-sensitive adhesive composition of claim 1 or 2 on one side of a resin film. Surface protective film using the adhesive film of claim 13. Surface protective film for polarizing plates using the adhesive film of claim 13. An optical film having a pressure-sensitive adhesive layer formed by laminating a pressure-sensitive adhesive layer obtained by crosslinking the pressure-sensitive adhesive composition of claim 1 or 2 on at least one side of the optical film. The method of claim 13,
An adhesive film having antistatic treatment and antifouling treatment on a side opposite to the side on which the adhesive layer is formed on one side of the resin film.