JP5924324B2 - Adhesive composition and use thereof - Google Patents

Description

  The present invention is a pressure-sensitive adhesive composition capable of suppressing the lifting and peeling of a pressure-sensitive adhesive sheet due to a high temperature and high humidity load while maintaining followability to a level difference, and having excellent adhesion to an olefinic adherend. And an adhesive product using the same.

The pressure-sensitive adhesive (also referred to as a pressure-sensitive adhesive) is processed into a form such as a tape or a label, and is used in a wide range of applications. Further, the adherend is also applied to various substances such as plastic, paper, metal, glass and ceramics.
On the other hand, due to the dramatic advancement of electronics technology in recent years, various flat panel displays (FPD) such as liquid crystal displays (LCD) and plasma display panels (PDP) have come to be used as display devices in various fields. It was.
These display devices generally have a laminated structure in which a transparent plastic material such as glass or polycarbonate is bonded with an adhesive. In such applications, the pressure-sensitive adhesive has transparency that does not impair the visibility of transparent plastic substrates, optical films, etc., and after severe durability tests under high temperature or high temperature and high humidity conditions. However, it is required that peeling and floating from the substrate interface do not occur. In particular, when a plastic plate such as a polycarbonate resin plate or an acrylic resin plate is used as the substrate, outgas which is considered to be caused by absorbed moisture or residual volatile substances is generated. For this reason, a plastic substrate and an optical film made of a base film having a barrier property such as a polyethylene terephthalate (PET) film were bonded together with an adhesive to obtain a laminate, which was then exposed to high temperature and high humidity. In this case, bubbles (foaming) generated from a plastic substrate or the like may cause floating or peeling at the adhesive interface with the pressure-sensitive adhesive layer, which not only causes a problem in appearance but also significantly impairs visibility. .

Various pressure-sensitive adhesive compositions have been proposed for the above problems.
Patent Document 1 discloses a method for suppressing floating and peeling by sticking a pressure-sensitive adhesive layer having high adhesive strength and excellent shape stability to a substrate by using a pressure-sensitive adhesive having a high storage elastic modulus. Yes. In Patent Documents 2 and 3, a low molecular weight polymer, in particular, a low molecular weight acrylic polymer that is excellent in compatibility and transparency with an acrylic adhesive polymer is added to the pressure-sensitive adhesive, so that it is flexible against deformation of the substrate. A method for suppressing lifting and peeling by using an adhesive layer excellent in stress relaxation that can cope with the above is disclosed.
Patent Document 4 discloses a pressure-sensitive adhesive comprising a specific (meth) acrylic copolymer, a specific acrylic copolymer oligomer having an SP value difference of 1.0 or less from the copolymer, and a crosslinking agent. It is described that the composition has a good balance of performance such as durability, adhesiveness, step following property, corrosiveness, and transparency.

JP 2006-235568 A JP 2012-41453 A JP 2011-232470 A JP 2011-162593 A

  The pressure-sensitive adhesive composition described in Patent Document 1 has improved performance for preventing floating and peeling after a high temperature and high humidity load. However, the elasticity of the adhesive is necessary when a layer configuration in which a pressure-sensitive adhesive layer is provided with a printed layer interposed therebetween, such as a touch panel application, and in a case where a configuration in which a pressure-sensitive adhesive layer is provided on a reflective surface having a complicated uneven shape is required. Since the rate is high, there is a problem in that the followability to the level difference is insufficient, and voids are generated in the concavo-convex portion and the end face of the printed layer.

In addition, the pressure-sensitive adhesive compositions described in Patent Documents 2 and 3 are effective in preventing floating and peeling due to differences in thermal shrinkage from the base material, but from a plastic substrate under high temperature and high humidity conditions. The floating and peeling due to the outgassing of the water cannot be sufficiently suppressed.
Although the pressure-sensitive adhesive composition described in Patent Document 4 also has improved performance such as transparency and level-following property, it is a satisfactory level particularly when the pressure-sensitive adhesive sheet is bonded to a plastic substrate. It was not a thing.

  Furthermore, in recent years, in applications such as liquid crystal televisions, touch panels, and mobile phones, cycloolefin polymers (COP) are increasingly used as display device materials because of their excellent optical properties and moisture absorption / moisture resistance. . Since olefin-based materials such as COP are generally difficult-to-adhere adherends, pressure-sensitive adhesives are required to exhibit good adhesion to these materials.

  The object of the present invention is to exhibit sufficient transparency and maintain followability to steps, and even when using various adherends, especially plastic substrates, floating or peeling after high temperature and high humidity load It is providing the adhesive composition which is excellent also in the durability which can prevent that, and is excellent also in the adhesiveness to an olefin type adherend, and also the adhesive product using this.

  As a result of intensive studies in view of the above problems, the present invention is an acrylic pressure-sensitive adhesive composition containing a specific vinyl polymer, and the specific pressure-sensitive adhesive sheet comprising the pressure-sensitive adhesive composition has a specific strength. By this, it is possible to provide the prevention of lifting and peeling after high temperature and high humidity load while maintaining the followability to the step, and also exhibits excellent adhesion to olefinic adherends. That is, the present invention has been completed.

The present invention is as follows.
[1] Glass transition temperature (Tg) of 30 to 150 ° C., a vinyl polymer a number average molecular weight of 500 to 10,000 (A), A acrylic-based adhesive polymer (B) and an adhesive containing a crosslinking agent A composition comprising:
The vinyl polymer (A) includes, as monomers constituting the vinyl polymer (A), isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, cyclohexyl (meth) acrylate, (meta ) Containing one or more vinyl monomers selected from adamantyl acrylate and methyl (meth) acrylate in a range of 10 to 100% by mass;
The acrylic pressure-sensitive adhesive polymer (B) contains an alkoxyalkyl (meth) acrylate in the range of 30 to 99% by mass in all constituent monomers.
The proportion of the acrylic adhesive polymer (B) the vinyl polymer to 100 parts by weight (A) is 0.5 to 60 parts by weight,
The ratio of the crosslinking agent to 100 parts by mass of the acrylic adhesive polymer (B) is 0.01 to 10 parts by mass,
Tg of the adhesive composition is the -80 to -10 ° C.,
The adhesive strength of a pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer having a film thickness of 50 μm made of the pressure-sensitive adhesive composition on a 100 μm-thick polyethylene terephthalate film substrate at 60 ° C. and a peeling rate of 30 mm / min. 3.0N / 25mm or more der is,
The vinyl polymer (A) is partially segregated on the surface layer in the pressure-sensitive adhesive layer obtained by applying the pressure-sensitive adhesive composition to the separator, then drying and crosslinking reaction, so that X-rays of the pressure-sensitive adhesive layer can be obtained. A pressure-sensitive adhesive composition, wherein Tg calculated from the composition of the surface layer portion obtained by photoelectron spectroscopic analysis is 30 ° C. or more higher than Tg of the pressure-sensitive adhesive composition.
[2] The pressure-sensitive adhesive composition according to [1], wherein the monomer constituting the vinyl polymer (A) contains an aromatic vinyl compound.
[3] The pressure-sensitive adhesive composition according to [1] or [2], wherein the acrylic pressure-sensitive adhesive polymer (B) has a weight average molecular weight of 100,000 or more and 2,000,000 or less.
[4] the adhesive sheet comprising the above [1] applied to the separator a pressure-sensitive adhesive composition according to any one of to [3], Ru one surface bonded to a substrate and dried to obtained adhesive layer step Manufacturing method .
[5] A glass plate and / or a transparent plastic plate is provided on one or both sides of the pressure-sensitive adhesive layer obtained by applying the pressure-sensitive adhesive composition according to any one of [1] to [3] to a separator and drying it. method for producing a pressure-sensitive adhesive workpiece comprising cemented Ru process.

  According to the pressure-sensitive adhesive composition of the present invention, even when a transparent plastic substrate is used while maintaining sufficient transparency and followability to a level difference, the pressure-sensitive adhesive sheet adhesion interface after high temperature and high humidity load is used. It is possible to prevent floating and peeling.

The present invention is a pressure-sensitive adhesive composition containing a specific vinyl polymer, wherein a specific pressure-sensitive adhesive sheet comprising the pressure-sensitive adhesive composition exhibits a specific pressure-sensitive adhesive strength, and the pressure-sensitive adhesive composition. The present invention relates to a pressure sensitive adhesive product.
In addition, in the pressure-sensitive adhesive composition of the present invention, Tg calculated from the composition of the surface layer portion obtained by X-ray photoelectron spectroscopy of the pressure-sensitive adhesive layer obtained from the pressure-sensitive adhesive composition is the total pressure-sensitive adhesive composition. A pressure-sensitive adhesive composition that is 30 ° C. or higher than Tg is included.
The present invention will be described in detail below. In the present specification, “(meth) acryl” means acryl and / or methacryl.

  The pressure-sensitive adhesive composition according to the present invention contains a vinyl polymer (A) and an acrylic pressure-sensitive polymer (B). Details of the vinyl polymer (A), the acrylic pressure-sensitive adhesive polymer (B), and the pressure-sensitive adhesive composition containing these will be sequentially described below.

[Vinyl polymer (A)]
The vinyl polymer (A) of the present invention is a polymer having a glass transition temperature (Tg) of 30 to 150 ° C, more preferably Tg in the range of 40 to 150 ° C, and Tg in the range of 70 to 150 ° C. Further preferred. In the present invention, a value measured by differential scanning calorimetry (DSC) at a heating rate of 10 ° C./min is adopted as Tg. If Tg is less than 30 ° C., the adhesion strength to various adherends may not be sufficient and the durability may be inferior. Moreover, generally 150 degreeC is not exceeded from the restrictions of a raw material monomer, etc.

As the monomer constituting the vinyl polymer (A), various vinyl unsaturated compounds having radical polymerizability can be used, for example, (meth) acrylic compounds, aromatic vinyl compounds, unsaturated compounds. Carboxylic acid, unsaturated acid anhydride, hydroxyl group-containing unsaturated compound, amino group-containing unsaturated compound, amide group-containing unsaturated compound, alkoxyl group-containing unsaturated compound, cyano group-containing unsaturated compound, nitrile group-containing unsaturated compound And maleimide compounds. These compounds may be used alone or in combination of two or more.
Among these, it is preferable that the main component is a (meth) acrylic compound from the viewpoint of good compatibility with the acrylic adhesive polymer. The specific use amount of the (meth) acrylic compound is preferably in the range of 10 to 100% by mass, more preferably in the range of 30 to 95% by mass, and still more preferably in the range of 50 to 90% by mass.

(Meth) acrylic compounds include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, (meth ) Isobutyl acrylate, tert-butyl (meth) acrylate, amyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth ) (Meth) acrylic acid alkyl esters such as n-dodecyl acrylate and n-octadecyl (meth) acrylate; cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate , Cyclododecyl (meth) acrylate, isobornyl (meth) acrylate, Aliphatic cyclic vinyl monomers such as (meth) acrylic acid adamantyl; phenyl (meth) acrylate, benzyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, etc. It is done. These compounds may be used alone or in combination of two or more.
Among these, isobornyl (meth) acrylate is capable of setting a relatively high Tg, has a high effect of suppressing lifting and peeling of the pressure-sensitive adhesive sheet, and has good adhesion to an olefin-based adherend. , Dicyclopentanyl (meth) acrylate, cyclohexyl (meth) acrylate and adamantyl (meth) acrylate are preferred.

  Examples of the aromatic vinyl compound include styrene, α-methyl styrene, o-methyl styrene, p-methyl styrene, vinyl toluene, β-methyl styrene, ethyl styrene, p-tert-butyl styrene, vinyl xylene, vinyl naphthalene, and the like. Can be mentioned. These compounds may be used alone or in combination of two or more.

  Examples of the unsaturated carboxylic acid include (meth) acrylic acid, ethacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, cinnamic acid, and monoalkyl esters of unsaturated dicarboxylic acid (maleic acid, Fumaric acid, itaconic acid, citraconic acid, maleic anhydride, itaconic anhydride, monoalkyl esters such as citraconic anhydride) and the like. These compounds may be used alone or in combination of two or more.

  Examples of the unsaturated acid anhydride include maleic anhydride, itaconic anhydride, citraconic anhydride, and the like. These compounds may be used alone or in combination of two or more.

  Examples of the hydroxyl group-containing unsaturated compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, ( Mono (meth) acrylic acid esters of polyalkylene glycols such as 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene glycol, polypropylene glycol, p-hydroxystyrene, m-hydroxystyrene, o -Hydroxystyrene, p-isopropenylphenol, m-isopropenylphenol, o-isopropenylphenol and the like. These compounds may be used alone or in combination of two or more.

  Examples of the amino group-containing unsaturated compound include dimethylaminomethyl (meth) acrylate, diethylaminomethyl (meth) acrylate, 2-dimethylaminoethyl (meth) acrylate, 2-diethylaminoethyl (meth) acrylate, (meth) 2- (di-n-propylamino) ethyl acrylate, 2-dimethylaminopropyl (meth) acrylate, 2-diethylaminopropyl (meth) acrylate, 2- (di-n-propylamino) (meth) acrylate Propyl, 3-dimethylaminopropyl (meth) acrylate, 3-diethylaminopropyl (meth) acrylate, 3- (di-n-propylamino) propyl (meth) acrylate, and the like. These compounds may be used alone or in combination of two or more.

  Examples of the amide group-containing unsaturated compound include (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N-methylol (meth) acrylamide and the like. These compounds may be used alone or in combination of two or more.

  Examples of the alkoxyl group-containing unsaturated compound include 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2- (n-propoxy) ethyl (meth) acrylate, 2- (meth) acrylic acid 2- (N-butoxy) ethyl, 3-methoxypropyl (meth) acrylate, 3-ethoxypropyl (meth) acrylate, 2- (n-propoxy) propyl (meth) acrylate, 2- (n) (meth) acrylate -Butoxy) propyl and the like. These compounds may be used alone or in combination of two or more.

  As the cyano group-containing unsaturated compound, cyanomethyl (meth) acrylate, 1-cyanoethyl (meth) acrylate, 2-cyanoethyl (meth) acrylate, 1-cyanopropyl (meth) acrylate, (meth) acrylic acid 2 -Cyanopropyl, 3-cyanopropyl (meth) acrylate, 4-cyanobutyl (meth) acrylate, 6-cyanohexyl (meth) acrylate, 2-ethyl-6-cyanohexyl (meth) acrylate, (meth) Examples include 8-cyanooctyl acrylate. These compounds may be used alone or in combination of two or more.

  Examples of the nitrile group-containing unsaturated compound include (meth) acrylonitrile, ethacrylonitrile, α-ethylacrylonitrile, α-isopropylacrylonitrile, α-chloroacrylonitrile, α-fluoroacrylonitrile and the like. These compounds may be used alone or in combination of two or more.

  Examples of the maleimide compound include maleimide, N-methylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-dodecylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N- (2-methylphenyl) maleimide, N -(4-Methylphenyl) maleimide, N- (2,6-dimethylphenyl) maleimide, N- (2,6-diethylphenyl) maleimide, N-benzylmaleimide, N-naphthylmaleimide and the like. These compounds may be used alone or in combination of two or more.

In addition to the above compounds, dialkyl esters of unsaturated dicarboxylic acids, vinyl ester compounds, vinyl ether compounds and the like can also be used.
Examples of the dialkyl ester of unsaturated dicarboxylic acid include dialkyl esters such as maleic acid, fumaric acid, itaconic acid, citraconic acid, maleic anhydride, itaconic anhydride, and citraconic anhydride.
Examples of the vinyl ester compound include methylene aliphatic monocarboxylic acid ester, vinyl acetate, vinyl propionate, vinyl pivalate, vinyl butyrate, vinyl benzoate, vinyl formate, and vinyl cinnamate.
Examples of the vinyl ether compound include vinyl methyl ether, vinyl ethyl ether, vinyl n-butyl ether, vinyl isobutyl ether, vinyl phenyl ether, vinyl cyclohexyl ether and the like.

The number average molecular weight (Mn) of the vinyl polymer (A) is 500 to 10,000, preferably 500 to 7,000, and more preferably 1,000 to 5,000. When Mn exceeds 10,000, the compatibility with the acrylic adhesive polymer (B) is deteriorated. On the other hand, in order to produce a polymer having an Mn of less than 500, there are problems such as using a large amount of a polymerization initiator and a chain transfer agent and causing a decrease in productivity.
Further, the ratio (Mw / Mn) between the weight average molecular weight (Mw) and the above (Mn) is preferably 3.0 or less, more preferably 2.2 or less, from the viewpoint that good adhesive strength is easily obtained. 1.8 or less is more preferable.
Here, the number average molecular weight Mn is a standard polystyrene conversion value obtained using gel permeation chromatography (GPC).

The vinyl polymer (A) of the present invention is not particularly limited with respect to its production method, but can be easily obtained by polymerizing the above monomers by employing a known radical polymerization method such as a solution polymerization method, for example. be able to.
In the case of the solution polymerization method, an organic solvent and a vinyl monomer raw material are charged into a reactor, a thermal polymerization initiator such as an organic peroxide or an azo compound is added, and the mixture is heated to 50 to 300 ° C. for copolymerization. As a result, the intended vinyl polymer can be obtained. The vinyl polymer may be used as a solution dissolved in an organic solvent, or may be used by distilling off the solvent by heating and decompression treatment or the like.
The charging method of each raw material including the monomer may be batch initial batch charging in which all raw materials are charged at once, or semi-continuous charging in which at least one raw material is continuously fed into the reactor. A continuous polymerization method in which the raw materials are continuously supplied and the product resin is continuously withdrawn from the reactor may be used.

  As the organic solvent used in the solution polymerization method, organic hydrocarbon compounds are suitable, cyclic ethers such as tetrahydrofuran and dioxane, aromatic hydrocarbon compounds such as benzene, toluene and xylene, ethyl acetate and butyl acetate and the like. Examples include esters, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, and alcohols such as methyl orthoformate, methyl orthoacetate, methanol, ethanol, and isopropanol. One or more of these can be used. Among these polymerization solvents, ethyl acetate, butyl acetate, acetone, and methyl ethyl ketone, which have a relatively low boiling point so as to dissolve the vinyl polymer well and facilitate purification, are preferable.

  The initiator used in the present invention may be an azo compound, an organic peroxide, an inorganic peroxide, or the like, but is not particularly limited. You may use the redox type polymerization initiator which consists of a well-known oxidizing agent and a reducing agent. Similarly, known chain transfer agents can be used in combination.

  Examples of the azo compound include 2,2′-azobis (isobutyronitrile), 1,1-azobis (cyclohexane-1-carbonitrile), azocumene, and 2,2′-azobis (2-methylbutyronitrile). 2,2′-azobisdimethylvaleronitrile, 4,4′-azobis (4-cyanovaleric acid), 2- (tert-butylazo) -2-cyanopropane, 2,2′-azobis (2,4,4) 4-trimethylpentane), 2,2′-azobis (2-methylpropane), dimethyl 2,2′-azobis (2-methylpropionate) and the like.

  Examples of the organic peroxide include cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (tert-butylperoxy) cyclohexane, n-butyl-4,4-bis (tert-butylperoxy) valerate, cumene hydroperoxide, 2,5-dimethylhexane-2,5-dihydro Peroxide, 1,3-bis (tert-butylperoxy) -m-isopropyl) benzene, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, diisopropylbenzene peroxide, tert-butyl Cumyl peroxide, deca Ile peroxide, lauroyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, bis (tert-butylcyclohexyl) peroxydicarbonate, tert-butylperoxybenzoate, 2,5-dimethyl-2,5- Examples include di (benzoylperoxy) hexane.

Examples of the inorganic peroxide include potassium persulfate, sodium persulfate, and ammonium persulfate.
Redox polymerization initiators include sodium sulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, ascorbic acid, ferrous sulfate, etc. as reducing agents, potassium peroxodisulfate, hydrogen peroxide, tert-butyl hydroper What used an oxide etc. as an oxidizing agent can be used.

  The vinyl polymer (A) of the present invention can also be obtained by continuous polymerization in a temperature range of 180 to 350 ° C. using a stirred tank reactor. In this polymerization method, since a relatively low molecular weight vinyl polymer can be obtained without substantially using a polymerization initiator or a chain transfer agent, a polymer having a high purity is obtained. However, it is preferable because it is advantageous. When the polymerization temperature is lower than 180 ° C., a polymerization initiator and a large amount of chain transfer agent are required for the polymerization reaction, and the obtained copolymer is easily colored and generates an unpleasant odor. On the other hand, when the polymerization temperature exceeds 350 ° C., a decomposition reaction is likely to occur during the polymerization reaction, and the resulting copolymer is colored, so that the transparency of the pressure-sensitive adhesive layer obtained from the pressure-sensitive adhesive composition containing this is lowered. Is concerned. Furthermore, according to such a polymerization method, a vinyl polymer having a small molecular weight distribution range can be obtained. The polymerization initiator may be optionally used, but it is preferably used at about 1% by weight or less based on the total monomers.

[Acrylic adhesive polymer (B)]
The acrylic adhesive polymer (B) is a polymer containing (meth) acrylic acid esters as main structural units. The glass transition temperature (Tg) is preferably a polymer having an adhesive property in the range of −80 to −30 ° C., and more preferably in the range of −80 to −40 ° C. When Tg is less than −80 ° C., the cohesive force of the obtained pressure-sensitive adhesive tends to be insufficient and curved surface adhesion tends to deteriorate. When it exceeds −30 ° C., the step following property and the adhesive strength at low temperature Etc. may not be sufficient.

Further, the acrylic tacky polymer (B) preferably has a weight average molecular weight (Mw) of 100,000 or more and 250,000 or more from the viewpoint of exhibiting sufficient cohesive force and good adhesiveness. More preferably, it is more preferably 400,000 or more.
On the other hand, if the weight average molecular weight is too high, the step following property tends to be lowered, and the handling in production becomes difficult. Therefore, the upper limit is preferably 2,000,000 or less, more preferably 1,500,000 or less, and even more preferably 1,000,000 or less.

  The monomer constituting the acrylic adhesive polymer (B) is a (meth) acrylic acid having an alkyl group having 4 to 12 carbon atoms in that an acrylic copolymer having a low Tg and having an adhesive property is obtained. Examples include alkyl esters and alkoxyalkyl (meth) acrylates such as methoxymethyl (meth) acrylate, ethoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, and ethoxyethyl (meth) acrylate. Of these, one or more of them can be used.

  Examples of the (meth) acrylic acid alkyl ester having an alkyl group having 4 to 12 carbon atoms include n-butyl (meth) acrylate, isobutyl (meth) acrylate, n-hexyl (meth) acrylate, and (meth) acrylic. N-octyl acid, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, (meth) acrylic Examples of preferred monomers include n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, and (meth). Examples include n-nonyl acrylate and isononyl (meth) acrylate.

  The amount of the (meth) acrylic acid alkyl ester having an alkyl group having 4 to 12 carbon atoms and / or the alkoxyalkyl (meth) acrylate is 30 to 30 based on the total constituent monomers of the acrylic copolymer. 100 mass% is preferable and 50-99 mass% is still more preferable. When the amount is less than 30% by mass, the resulting adhesive composition has insufficient adhesive strength, tackiness, low-temperature adhesiveness, and the like.

  The acrylic adhesive polymer (B) contains other monomers copolymerizable with the above (meth) acrylic acid alkyl ester and / or (meth) acrylic acid alkoxyalkyl as long as the adhesive performance is not impaired. Can be used. Examples of the copolymerizable monomer include α, β-ethylenically unsaturated carboxylic acid monomers such as (meth) acrylic acid, itaconic acid, maleic acid and fumaric acid; methyl (meth) acrylate, (meth ) (Meth) acrylic acid alkyl ester having an alkyl group having 1 to 3 carbon atoms such as ethyl acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, etc .; styrene, α-methylstyrene, vinyltoluene, etc. Vinyl aromatic monomers such as cyclohexyl (meth) acrylate, methyl cyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, isobornyl (meth) acrylate, etc. Aliphatic cyclic vinyl monomer; unsaturated dicarbonate such as itaconic acid monoethyl ester, fumaric acid monobutyl ester Monoalkyl ester of boric acid; 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate And hydroxyl group-containing monomers such as polyethylene-polypropylene glycol mono (meth) acrylate; ethylenically unsaturated carboxylic acid amides such as acrylamide, N-methylolacrylamide, N-methoxymethylacrylamide, N-methoxybutylacrylamide, and N-substituted compounds Unsaturated alcohols such as allyl alcohol; (meth) acrylonitrile, vinyl acetate, glycidyl (meth) acrylate, diacetone acrylamide, etc., and one of these It is possible to use more than seeds.

  The acrylic adhesive polymer (B) can also be obtained by a known radical polymerization method such as a solution polymerization method, a suspension polymerization method, or an emulsion polymerization method.

[Adhesive composition]
The pressure-sensitive adhesive composition of the present invention contains 0.5 to 60 parts by mass of the vinyl polymer (A) in terms of solid content and 100 parts by mass of the acrylic adhesive polymer (B), and is preferably contained. The amount is 1 to 40 parts by mass, more preferably 3 to 30 parts by mass. When the amount of the vinyl polymer (A) used is 0.5 parts by mass or more, the effect of suppressing floating or peeling after heat and heat tends to be sufficiently expressed. And good adhesiveness including initial adhesive strength (tack) can be obtained.

  If the adhesive composition of this invention contains the said vinyl polymer (A) and the said acrylic adhesive polymer (B) in a defined amount, there will be no special restriction | limiting in the mixing method. For example, a method of mixing the vinyl polymer (A) and the acrylic adhesive polymer (B) may be used, or the acrylic adhesive polymer (B) is polymerized in the presence of the vinyl polymer (A). It may be obtained by.

  The glass transition temperature (Tg) of the pressure-sensitive adhesive composition is in the range of −80 to 0 ° C., preferably in the range of −80 to −10 ° C., and more preferably in the range of −70 to −20 ° C. When Tg is less than −80 ° C., the cohesive strength of the resulting pressure-sensitive adhesive tends to be insufficient, and the curved surface adhesion and the like tend to deteriorate. When it exceeds 0 ° C., the step following property and the adhesive strength under low temperature conditions Etc. may not be sufficient.

The pressure-sensitive adhesive composition of the present invention comprises polycarbonate and polymethyl at 60 ° C. and a peeling rate of 30 mm / min of a pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition and a thickness of 50 μm on a 100 μ-thick polyethylene terephthalate film substrate. The adhesive strength to the methacrylate plate is 3.0 N / 25 mm or more.
By setting the adhesive strength under a high temperature condition of 60 ° C. to 3.0 N / 25 mm or more, even when a transparent plastic substrate such as polycarbonate and polymethyl methacrylate is used, Since the adhesive force is sufficiently high, the pressure-sensitive adhesive sheet can be prevented from floating or peeling off. Moreover, it is more preferable that the adhesive strength with respect to the polycarbonate and the polymethylmethacrylate plate at a peeling rate of 30 mm / min at 85 ° C. is 3.0 N / 25 mm or more.

Here, in preparing the pressure-sensitive adhesive sheet, the pressure-sensitive adhesive composition is directly applied to a polyester film substrate and dried to obtain a pressure-sensitive adhesive sheet, or once coated on a release paper or the like, then polyester Any method of transferring to a film substrate may be adopted.
Although drying may be performed at room temperature, from the viewpoint of productivity and the like, the drying is usually performed for several seconds to several tens of minutes under a heating condition of 40 to 150 ° C. using a dryer. The method is common.

  In addition, the measurement of the adhesive strength is performed according to JIS Z 0237 “Testing method for adhesive tape / adhesive sheet”, and the adhesive strength to polycarbonate and polymethylmethacrylate plate according to the conditions described in the Examples section described later. Measure.

The pressure-sensitive adhesive composition of the present invention is a composition of the surface layer portion obtained by X-ray photoelectron spectroscopy analysis of the pressure-sensitive adhesive layer when the pressure-sensitive adhesive composition is applied to a separator and dried to obtain a pressure-sensitive adhesive layer. It is preferable that Tg calculated from is higher by 30 ° C. or more than Tg of the whole pressure-sensitive adhesive composition. When the Tg of the surface layer portion is 30 ° C. or higher than the Tg of the entire pressure-sensitive adhesive composition, a laminate obtained by bonding a transparent plastic substrate such as polycarbonate and polymethyl methacrylate and an optical film with a pressure-sensitive adhesive is used. Even when exposed to moisture, floating and peeling at the adhesive interface with the pressure-sensitive adhesive layer due to bubbles (foaming) generated from a plastic substrate or the like are suppressed, and good durability is exhibited.
As described above, “Tg calculated from the composition of the surface layer portion” is obtained by calculation from the composition ratio of the vinyl polymer (A) and the acrylic adhesive polymer (B) obtained from X-ray photoelectron spectroscopy (XPS). The Tg of the composition that forms the surface layer from the surface of the pressure-sensitive adhesive layer to the depth of about 5 nm. The details of the measurement method follow the operations described in the examples described later.

The vinyl polymer (A) of the present invention has appropriate compatibility with the acrylic adhesive polymer (B). For this reason, the pressure-sensitive adhesive layer obtained from the pressure-sensitive adhesive composition containing them exhibits good transparency, and part of the vinyl polymer (A) is segregated in the pressure-sensitive adhesive layer, and the vinyl polymer (A ) May be higher than other portions. This behavior can be adjusted by setting the composition (polarity) and molecular weight of the vinyl polymer (A) with respect to the acrylic adhesive polymer.
Thus, when it takes the structure where the density | concentration of the vinyl polymer (A) in the surface layer of an adhesive layer becomes higher than others, even if it is a laminated body which affixed the adhesive sheet to the transparent plastic substrate, the adhesion of the vicinity of an adhesion interface Since the agent layer has a relatively high Tg, the pressure-sensitive adhesive sheet is prevented from being lifted or peeled off by the outgas generated from the substrate. Moreover, it has sufficient softness | flexibility as the whole adhesive layer, and can show favorable level | step difference followability. Furthermore, good adhesion to olefinic adherends is exhibited.

  The pressure-sensitive adhesive composition of the present invention is a cross-linking agent (curing agent), a tackifier, a plasticizer, an antioxidant, an ultraviolet absorber, aging as necessary in addition to the tackifier and the acrylic tacky polymer. It can also be set as the composition containing additives, such as an inhibitor, a flame retardant, an antifungal agent, a silane coupling agent, a filler, and a coloring agent.

  Examples of the crosslinking agent (curing agent) include a glycidyl compound having two or more glycidyl groups, an isocyanate compound having two or more isocyanate groups, an aziridine compound having two or more aziridinyl groups, an oxazoline compound having an oxazoline group, and a metal chelate compound. And butylated melamine compounds. Of these, aziridine compounds, glycidyl compounds and isocyanate compounds are preferred.

  Examples of the aziridine compound include 1,6-bis (1-aziridinylcarbonylamino) hexane, 1,1 ′-(methylene-di-p-phenylene) bis-3,3-aziridylurea, 1,1′-. (Hexamethylene) bis-3,3-aziridylurea, ethylenebis- (2-aziridinylpropionate), tris (1-aziridinyl) phosphine oxide, 2,4,6-triaziridinyl-1,3,5- And triazine, trimethylolpropane-tris- (2-aziridinylpropionate), and the like.

  Examples of the glycidyl compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerin diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexanediol diglycidyl. Ether, tetraglycidylxylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, trimethylolpropane polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether A functional glycidyl compound is mentioned.

As the isocyanate compound, a compound having two or more isocyanate groups is preferably used.
As the isocyanate compound, aromatic, aliphatic and alicyclic isocyanate compounds, and modified products (such as prepolymers) of these isocyanate compounds can be used.

As aromatic isocyanate, diphenylmethane diisocyanate (MDI), crude diphenylmethane diisocyanate, tolylene diisocyanate, naphthalene diisocyanate (NDI), p-phenylene diisocyanate (PPDI), xylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), tolidine A diisocyanate (TODI) etc. are mentioned.
Examples of the aliphatic isocyanate include hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI), and lysine triisocyanate (LTI).
Examples of the alicyclic isocyanate include isophorone diisocyanate (IPDI), cyclohexyl diisocyanate (CHDI), hydrogenated XDI (H6XDI), and hydrogenated MDI (H12MDI).
The modified isocyanate includes urethane modified products, dimers, trimers, carbodiimide modified products, allophanate modified products, burette modified products, urea modified products, isocyanurate modified products, oxazolidone modified products, isocyanates. Examples thereof include base end prepolymers.

  When the pressure-sensitive adhesive composition of the present invention contains a crosslinking agent (curing agent), the content thereof is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer. Preferably it is 0.03-5 mass parts, More preferably, it is 0.05-2 mass parts.

  Examples of the tackifier include rosin derivatives such as rosin ester, gum rosin, tall oil rosin, hydrogenated rosin ester, maleated rosin, and disproportionated rosin ester; terpene phenol resin, α-pinene, β-pinene, limonene, etc. (Hydrogenated) petroleum resin; coumarone-indene resin; hydrogenated aromatic copolymer; styrene resin; phenol resin; xylene resin; (meth) acrylic polymer, etc. .

  Examples of the plasticizer include phthalic acid esters such as di-n-butyl phthalate, di-n-octyl phthalate, bis (2-ethylhexyl) phthalate, di-n-decyl phthalate, diisodecyl phthalate; bis (2-ethylhexyl) adipate, di Adipic acid esters such as n-octyl adipate; Sebacic acid esters such as bis (2-ethylhexyl) sebacate, di-n-butyl sebacate; Azelaic acid esters such as bis (2-ethylhexyl) azelate; Paraffin such as chlorinated paraffin Glycols such as polypropylene glycol; epoxy-modified vegetable oils such as epoxidized soybean oil and epoxidized linseed oil; phosphate esters such as trioctyl phosphate and triphenyl phosphate; phosphorous acid s such as triphenyl phosphite Ester compounds such as esterified products of adipic acid and 1,3-butylene glycol; low molecular weight polymers such as low molecular weight polybutene, low molecular weight polyisobutylene, and low molecular weight polyisoprene; process oils, naphthenic oils, etc. Examples thereof include oils.

  Examples of the antioxidant include 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-tert-butyl-4-ethylphenol, stearyl-β- (3,5- Di-tert-butyl-4-hydroxyphenyl) propionate, 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), 4 , 4′-thiobis (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), 3,9-bis [1,1-dimethyl-2- [ β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl] 2,4,8,10-te Traoxaspiro [5.5] undecane, 1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3 , 5-di-tert-butyl-4-hydroxybenzyl) benzene, tetrakis- [methylene-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate] methane, bis [3, 3′-bis- (4′-hydroxy-3′-tert-butylphenyl) butyric acid] glycol ester, 1,3,5-tris (3 ′, 5′-di-tert-butyl-4′-hydroxy Benzyl) -S-triazine-2,4,6- (1H, 3H, 5H) trione, tocopherols and other phenolic antioxidants; dilauryl 3,3′-thiodi Sulfur antioxidants such as lopionate, dimyristyl 3,3′-thiodipropionate, stearyl 3,3′-thiodipropionate; triphenyl phosphite, diphenylisodecyl phosphite, 4,4′-butylidene-bis (3-methyl-6-tert-butylphenylditridecyl) phosphite, cyclic neopentanetetraylbis (octadecyl phosphite), tris (nonylphenyl) phosphite, tris (monononylphenyl) phosphite, tris (di Nonylphenyl) phosphite, diisodecylpentaerythritol diphosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10- (3,5-di-tert-butyl-4-hydroxybenzyl -9, 1 -Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene, tris (2,4-di-tert-butylphenyl) Phosphite, cyclic neopentanetetrayl bis (2,4-di-tert-butylphenyl) phosphite, cyclic neopentanetetrayl bis (2,6-di-tert-butyl-4-methylphenyl) phosphite And phosphorus antioxidants such as 2,2-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite.

  Examples of the UV absorber include salicylic acid UV absorbers such as phenyl salicylate, p-tert-butylphenyl salicylate, and p-octylphenyl salicylate; 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy -4-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4- Benzophenone ultraviolet absorbers such as methoxy-5-sulfobenzophenone and bis (2-methoxy-4-hydroxy-5-benzoylphenyl) methane; 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- 2'-hydroxy-5'-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3' -Tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2 '-Hydroxy-3', 5'-di-tert-amylphenyl) benzotriazole, 2- (2'-hydroxy-4'-octoxyphenyl) benzotriazole, 2- [2'-hydroxy-3 '-( 3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) -5'-methylphenyl] benzotriazole, 2,2-methylenebis 4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2- (2′-hydroxy-5′-methacryloxyphenyl) -2H-benzo Benzotriazole ultraviolet absorbers such as triazole and 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol]; Cyanoacrylate ultraviolet absorbers such as ethylhexyl-2-cyano-3,3′-diphenylacrylate, ethyl-2-cyano-3,3′-diphenylacrylate; nickel bis (octylphenyl) sulfide, [2,2′- Thiobis (4-tert-octylphenolate)]-n-butylamine nickel, nickel complex-3,5-di Examples thereof include nickel-based UV stabilizers such as -tert-butyl-4-hydroxybenzyl-phosphate monoethylate and nickel-dibutyldithiocarbamate.

  Examples of the anti-aging agent include poly (2,2,4-trimethyl-1,2-dihydroquinoline), 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, and 1- (N-phenyl). Amino) -naphthalene, styrenated diphenylamine, dialkyldiphenylamine, N, N′-diphenyl-p-phenylenediamine, N-phenyl-N′-isopropyl-p-phenylenediamine, N, N′-di-2-naphthyl-p -Phenylenediamine, 2,6-di-tert-butyl-4-methylphenol, mono (α-methylbenzyl) phenol, di (α-methylbenzyl) phenol, tri (α-methylbenzyl) phenol, 2,2 ′ -Methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl- -Tert-butylphenol), 4,4'-butylidenebis (6-tert-butyl-3-methylphenol), 4,4'-thiobis (6-tert-butyl-3-methylphenol), 1,1-bis ( 4-hydroxyphenyl) cyclohexane, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, 2-mercaptobenzimidazole, zinc salt of 2-mercaptobenzimidazole, 2-mercaptomethylbenzimidazole , Nickel dibutyldithiocarbamate, tris (nonylphenyl) phosphite, dilauryl thiodipropionate, distearyl thiodipropionate, and the like.

  Examples of the flame retardant include tetrabromobisphenol A, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, hexabromobenzene, tris (2,3-dibromopropyl) isocyanurate, 2,2- Halogen flame retardants such as bis (4-hydroxyethoxy-3,5-dibromophenyl) propane, decabromodiphenyl oxide, halogen-containing polyphosphate; ammonium phosphate, tricresyl phosphate, triethyl phosphate, tris (β-chloroethyl) ) Phosphorus flame retardants such as phosphate, trischloroethyl phosphate, trisdichloropropyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, acidic phosphate ester, nitrogen-containing phosphorus compounds; red phosphorus, tin oxide, trioxide Inorganic flame retardants such as Ntimmon, zirconium hydroxide, barium metaborate, aluminum hydroxide, magnesium hydroxide; poly (dimethoxysiloxane), poly (diethoxysiloxane), poly (diphenoxysiloxane), poly (methoxyphenoxysiloxane) Siloxane flame retardants such as methyl silicate, ethyl silicate, and phenyl silicate.

  Examples of the antifungal agent include benzimidazole, benzothiazole, trihaloallyl, triazole, and organic nitrogen sulfur compounds.

  Examples of the silane coupling agent include vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycid. Xylpropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-chloropropylmethoxysilane, vinyltrichlorosilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N- β (aminoethyl) -γ-aminopropyltrimethoxysilane and the like can be mentioned.

  Examples of the filler include inorganic powder fillers such as calcium carbonate, titanium oxide, mica and talc; fibrous fillers such as glass fibers and organic reinforcing fibers.

If the adhesive composition of this invention contains the said vinyl polymer (A) and an acrylic adhesive polymer (B), there will be no special restriction | limiting in the form. For example, it may be used as a form of a solvent-type pressure-sensitive adhesive composition dissolved in an organic solvent such as ethyl acetate, or a form of an emulsion-type pressure-sensitive adhesive composition in which an acrylic pressure-sensitive adhesive polymer and a tackifier are dispersed in an aqueous medium. It may be used as
In the case of the solution-type pressure-sensitive adhesive composition and the emulsion-type pressure-sensitive adhesive composition, the medium such as an organic solvent or water used is usually 20 to 80 parts by mass with respect to 100 parts by mass of the pressure-sensitive adhesive composition.

  When used as an emulsion-type pressure-sensitive adhesive, a stabilizer can be blended. This stabilizer is used for vinyl chloride such as cadmium stearate, zinc stearate, barium stearate, calcium stearate, lead dibutyltin dilaurate, tris (nonylphenyl) phosphite, triphenylphosphite, diphenylisodecylphosphite, etc. Stabilizer; di-n-octyltin bis (isooctylthioglycolate) salt, di-n-octyltin maleate polymer, di-n-octyltin dilaurate, di-n-octyltin maleate Ester salt, di-n-butyltin bismaleic acid ester salt, di-n-butyltin maleate polymer, di-n-butyltin bisoctylthioglycol ester salt, di-n-butyltin β-mercaptopropionate polymer, di -N-Butyl tin dilaure Di-n-methyltin bis (isooctyl mercaptoacetate) salt, poly (thiobis-n-butyltin sulfide), monooctyltin tris (isooctylthioglycolate ester), dibutyltin maleate, di-n-butyltin maleate ester・ Carboxylate and di-n-butyltin malate ester ・ Organic tin stabilizers such as mercaptides; tribasic lead sulfate, dibasic lead phosphite, basic lead sulfite, dibasic lead phthalate, silica Lead stabilizers such as lead acid, dibasic lead stearate, lead stearate; metal soap stabilizers such as cadmium soap, zinc soap, barium soap, lead soap, composite metal soap, calcium stearate Etc.

  In addition, the pressure-sensitive adhesive composition of the present invention includes a monofunctional and / or polyfunctional (meth) acrylic acid monomer, and a photopolymerization initiator in addition to the acrylic pressure-sensitive adhesive polymer and the tackifier. And so on, it may be used as a form of a so-called syrup-type photo-curing pressure-sensitive adhesive composition that is cured by active energy rays such as ultraviolet rays.

  In the case of the photocurable pressure-sensitive adhesive composition, the composition may contain an organic solvent or the like, but is generally used as a solventless type containing no solvents.

  Examples of the monofunctional (meth) acrylic acid monomers include (meth) acrylic acid alkyl esters having an alkyl group having 1 to 12 carbon atoms; (meth) acrylic acid cyclohexyl, (meth) acrylic acid dicyclopentyl, ( (Meth) acrylic esters having a cyclic structure such as isobornyl (meth) acrylate; hydroxy (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate Alkyl esters; (meth) acrylic acid and the like. These compounds may be used alone or in combination of two or more.

  Examples of the polyfunctional (meth) acrylic acid monomer include di (meth) acrylates of alkylene glycol such as butanediol di (meth) acrylate and hexanediol di (meth) acrylate; di (meth) triethylene glycol Di (meth) acrylates of polyalkylene glycols such as acrylates; trimethylolpropane tri (meth) acrylate and its ethylene oxide and / or propylene oxide modified products, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, etc. Is mentioned. In addition, a polymer (macromonomer) having a (meth) acryloyl group such as polyurethane (meth) acrylate and polyisoprene-based (meth) acrylate can also be used. Specific examples of the polyisoprene-based (meth) acrylate include an esterified product of a maleic anhydride adduct of isoprene polymer and 2-hydroxyethyl methacrylate. These compounds may be used alone or in combination of two or more.

Examples of the photopolymerization initiator include benzoin and its alkyl ethers, acetophenones, anthraquinones, thioxanthones, ketals, benzophenones, xanthones, acylphosphine oxides, α-diketones and the like.
Moreover, in order to improve the sensitivity by an active energy ray, a photosensitizer can also be used together.
Examples of the photosensitizer include benzoic acid and amine photosensitizers. These can also be used in combination of two or more.
As for the usage-amount of a photoinitiator and a photosensitizer, 0.01-10 mass parts is preferable with respect to 100 mass parts of monofunctional and / or polyfunctional (meth) acrylic-acid type monomers.

  As the photocurable resin composition of the present invention, in addition to the photocurable pressure-sensitive adhesive composition described above, the vinyl polymer (A), monofunctional and / or polyfunctional (meth) acrylic acid-based monopolymer is used. It can also be used as a photocurable adhesive composition comprising a monomer and a composition containing a photopolymerization initiator. The said acrylic adhesive polymer (B) can be mixed with the said photocurable adhesive composition as needed.

  The pressure-sensitive adhesive composition of the present invention is suitably used for laminating applications when forming laminates such as various optical films in addition to various general pressure-sensitive processed products such as pressure-sensitive adhesive films, pressure-sensitive adhesive sheets, pressure-sensitive adhesive tapes, and labels. be able to.

When applied to the above general pressure-sensitive processed product, after applying the pressure-sensitive adhesive composition of the present invention to one or both surfaces of various substrates, a pressure-sensitive adhesive layer is formed by irradiating active energy rays such as drying or UV, It can be set as an adhesive product such as an adhesive sheet or an adhesive tape. Moreover, the product which has an adhesion layer can also be obtained by making a composition into a molten state, applying to a base material, and cooling.
As the substrate, papers, films, cloths, nonwoven fabrics, metal foils, and the like can be used. The pressure-sensitive adhesive composition may be applied directly to these substrates, or applied to a release paper or the like. After being worked and dried, it may be transferred to a substrate.
The thickness (thickness after drying) of the pressure-sensitive adhesive formed on the pressure-sensitive adhesive sheet is selected depending on the application, but is usually in the range of 1 to 300 μm, preferably in the range of 5 to 250 μm, and further in the range of 10 to 200 μm. preferable.

  Specific examples of the general adhesive processed product include an adhesive sheet, an adhesive film, an adhesive tape, a pressure sensitive tape, a surface protective film, a surface protective tape, a masking tape, an electrical insulating tape, and a laminate.

  The pressure-sensitive adhesive composition of the present invention is excellent in transparency and moisture and heat whitening resistance, and has high tack and adhesive strength to various adherends such as glass. Therefore, a touch panel, a liquid crystal display device, and an organic EL display It is also suitable for bonding displays such as devices and plasma display panels and various optical films used therefor. Moreover, it is useful also for the adhesive use in electronic components, such as a flexible printed circuit board.

Hereinafter, the present invention will be specifically described based on examples. In addition, this invention is not limited to the following Example. In the following description, “part” means part by mass, and “%” means mass%.
In addition, various analyzes of the polymer obtained in this example were performed by the methods described below.

<Solid content>
About 1 g of the measurement sample was weighed (a), then the residue after drying at 155 ° C. for 30 minutes in the ventilation dryer was measured (b) and calculated from the following formula. A weighing bottle was used for the measurement. Other operations were in accordance with JIS K 0067-1992 (chemical product weight loss and residue test method).
Solid content (%) = (b / a) × 100

<Molecular weight measurement>
The molecular weight was measured by GPC under the following conditions.
GPC: Tosoh (HLC-8120)
Column: Tosoh (TSKgel-Super MP-M x 4)
Sample concentration: 0.1%
Flow rate: 0.6 ml / min Eluent: Tetrahydrofuran Column temperature: 40 ° C
Detector: Differential refractometer (RI)
Reference material: Polystyrene

<Glass transition point (Tg)>
Tg of the vinyl polymer (A), the acrylic adhesive polymer (B) and the adhesive composition was measured by DSC under the following conditions.
DSC: manufactured by TA Instrument (Q-100)
Temperature rise: 10 ° C / min Measurement atmosphere: Nitrogen

<Polymer composition>
The polymer composition was calculated from the monomer charge and the monomer consumption by GC measurement.
GC: Made by Agilent Technologies (7820A GC System)
Detector: FID
Column: 100% dimethylsiloxane (CP-Sil 5CB) Length 30m, inner diameter 0.32mm
Calculation method: Internal standard method

1. Synthetic Synthesis Example 1 of Vinyl Polymer (Synthesis of Polymer A-1)
In a four-necked flask with an internal volume of 1 liter, 198 parts by mass of butyl acetate and dimethyl 2,2′-azobis (2-methylpropionate) (trade name “V-601” manufactured by Wako Pure Chemical Industries, Ltd.) 4.4 A liquid mixture consisting of parts by mass was charged, and the liquid mixture was sufficiently degassed by bubbling nitrogen gas, and the internal temperature of the liquid mixture was raised to 90 ° C. Separately, 141 parts by mass of methyl methacrylate (hereinafter referred to as “MMA”), 110 parts by mass of isobornyl methacrylate (hereinafter referred to as “IBXMA”), 84 parts by mass of V-601, and 90 parts by mass of butyl acetate are dropped. Polymerization was carried out by dropping from a funnel into the flask over 5 hours. After completion of the dropping, the polymerization solution was added dropwise to a mixed solution consisting of 4800 parts by mass of methanol and 1200 parts by mass of distilled water, whereby the vinyl polymer in the polymerization solution was isolated to obtain a polymer A-1. The polymer composition of the obtained polymer A-1 was calculated from the charged amount and the monomer consumption by GC measurement. As a result, it was composed of 59% by mass of MMA and 41% by mass of IBXMA, and was Mw2520, Mn1900, Mw / Mn1.33. It was. Tg was 77 ° C.
The composition and analysis results of the polymer A-1 are shown in Table 1.

Synthesis Example 2 (Synthesis of Polymer A-2)
A four-necked flask with an internal volume of 1 liter is charged with a mixed liquid consisting of 230 parts by mass of butyl acetate and 2.8 parts by mass of V-601, and the mixed liquid is sufficiently degassed by bubbling with nitrogen gas. The internal temperature was increased to 90 ° C. Separately, a mixed solution consisting of 148 parts by mass of MMA, 108 parts by mass of dicyclopentanyl methacrylate (hereinafter referred to as “DCP”), 52 parts by mass of V-601, and 90 parts by mass of butyl acetate was added to the flask from the dropping funnel over 5 hours. The polymerization was carried out by dropwise addition. After completion of the dropwise addition, the polymerization solution was dropped into a mixed solution consisting of 4800 parts by mass of methanol and 1200 parts by mass of distilled water, whereby the vinyl polymer in the polymerization solution was isolated to obtain a polymer A-2.
The composition and analysis results of the polymer A-2 are shown in Table 1.

Synthesis Example 3 (Synthesis of Polymer A-3)
A four-necked flask with an internal volume of 1 liter is charged with a mixed liquid consisting of 226 parts by mass of butyl acetate and 2.9 parts by mass of V-601, and the mixed liquid is sufficiently degassed by bubbling with nitrogen gas. The internal temperature was increased to 90 ° C. Separately, polymerization was carried out by dropping a mixed liquid consisting of 64 parts by mass of MMA, 197 parts by mass of IBXMA, 56 parts by mass of V-601, and 90 parts by mass of butyl acetate into the flask from a dropping funnel over 5 hours. After completion of the dropping, the polymer solution was dropped into a mixed solution consisting of 4800 parts by mass of methanol and 1200 parts by mass of distilled water, whereby the vinyl polymer in the polymerization solution was isolated to obtain a polymer A-3.
The composition and analysis results of the polymer A-3 are shown in Table 1.

Synthesis Example 4 (Synthesis of Polymer A-4)
A mixed solution consisting of 38 parts by mass of IBXMA, 226 parts by mass of butyl acetate, and 8.7 parts by mass of V-601 was charged into a 4-liter flask having an internal volume of 1 liter, and this mixture was sufficiently degassed by bubbling nitrogen gas. The internal temperature of the mixed solution was raised to 90 ° C. Separately, polymerization was carried out by dropping a mixed liquid consisting of 213 parts by mass of IBXMA, 49 parts by mass of V-601 and 90 parts by mass of butyl acetate into the flask from a dropping funnel over 5 hours. After completion of the dropping, the polymerization solution was added dropwise to 6000 parts by mass of methanol to isolate the vinyl polymer in the polymerization solution, thereby obtaining a polymer A-4.
The composition and analysis results of the polymer A-4 are shown in Table 1.

Synthesis Example 5 (Synthesis of Polymer A-5)
A four-necked flask with an internal volume of 1 liter was charged with a mixed liquid consisting of 19 parts by mass of MMA, 11 parts by mass of styrene (hereinafter referred to as “St”), 224 parts by mass of butyl acetate, and 8.7 parts by mass of V-601. The liquid mixture was sufficiently degassed by bubbling nitrogen gas, and the internal temperature of the liquid mixture was raised to 90 ° C. Separately, polymerization was carried out by dropping a mixed solution consisting of 108 parts by mass of MMA, 93 parts by mass of St, 78 parts by mass of V-601, and 90 parts by mass of butyl acetate into the flask from a dropping funnel over 5 hours. After completion of the dropping, the polymerization solution was dropped into a mixed solution consisting of 4200 parts by mass of methanol and 1800 parts by mass of distilled water, whereby the vinyl polymer in the polymerization solution was isolated to obtain a polymer A-5.
The composition and analysis results of the polymer A-5 are shown in Table 1.

Synthesis Example 6 (Synthesis of Polymer A-6)
A four-necked flask with an internal volume of 1 liter is charged with a mixed solution consisting of 223 parts by mass of butyl acetate and 3.1 parts by mass of V-601, and this mixture is sufficiently degassed by bubbling with nitrogen gas. The internal temperature was raised to 90 ° C. Separately, polymerization was carried out by dropping a mixture of MMA 226 parts by mass, IBXMA 28 parts by mass, V-601 58 parts by mass, and butyl acetate 90 parts by mass from a dropping funnel into the flask over 5 hours. After completion of the dropwise addition, the polymerization solution was dropped into 6000 parts by mass of hexane to isolate the vinyl polymer in the polymerization solution, thereby obtaining a polymer A-6.
Table 1 shows the composition and analysis results of the polymer A-6.

Synthesis Example 7 (Synthesis of Polymer A-7)
A liquid mixture consisting of 263 parts by mass of butyl acetate and 1.1 parts by mass of V-601 was charged into a 4-liter flask having an internal volume of 1 liter, and this mixture was sufficiently degassed by bubbling with nitrogen gas. The internal temperature was raised to 90 ° C. Separately, polymerization was carried out by dropping a mixed liquid consisting of MMA 226 parts by mass, IBXMA 26 parts by mass, V-601 21 parts by mass, and butyl acetate 90 parts by mass from the dropping funnel into the flask over 5 hours. After completion of the dropping, the polymerization solution was added dropwise to 6000 parts by mass of hexane to isolate the vinyl polymer in the polymerization solution, thereby obtaining a polymer A-7.
Table 1 shows the composition and analysis results of the polymer A-7.

Synthesis Example 8 (Synthesis of Polymer A-8)
A four-necked flask with an internal volume of 1 liter was charged with a mixed solution consisting of 203 parts by mass of butyl acetate and 4.1 parts by mass of V-601, and this mixture was sufficiently degassed by bubbling with nitrogen gas. The internal temperature was raised to 90 ° C. Separately, polymerization was carried out by dropping a mixture of MMA 168 parts by mass, IBXMA 83 parts by mass, V-601 78 parts by mass, and butyl acetate 90 parts by mass from the dropping funnel into the flask over 5 hours. After completion of the dropwise addition, the polymer solution was dropped into a mixed solution consisting of 4800 parts by mass of methanol and 1200 parts by mass of distilled water, whereby the vinyl polymer in the polymerization solution was isolated to obtain a polymer A-8.
Table 1 shows the composition and analysis results of the polymer A-8.

Synthesis Example 9 (Synthesis of Polymer A-9)
A four-necked flask with an internal volume of 1 liter was charged with a mixed liquid consisting of 204 parts by mass of butyl acetate and 4.1 parts by mass of V-601, and the mixed liquid was sufficiently degassed by bubbling with nitrogen gas. The internal temperature was raised to 90 ° C. Separately, polymerization was carried out by dropping a mixed liquid consisting of 114 parts by mass of MMA, 141 parts by mass of IBXMA, 78 parts by mass of V-601, and 90 parts by mass of butyl acetate into the flask from a dropping funnel over 5 hours. After completion of the dropping, the polymerization solution was added dropwise to a mixed solution consisting of 4800 parts by mass of methanol and 1200 parts by mass of distilled water, whereby the vinyl polymer in the polymerization solution was isolated to obtain a polymer A-9.
Table 1 shows the composition and analysis results of the polymer A-9.

Synthesis Example 10 (Synthesis of Polymer A-10)
A mixed solution consisting of 280 parts by mass of butyl acetate and 0.3 part by mass of V-601 was charged into a 4-liter flask having an internal volume of 1 liter, and this mixture was sufficiently degassed by bubbling with nitrogen gas. The internal temperature was raised to 90 ° C. Separately, polymerization was performed by dropping a mixed liquid consisting of MMA 233 parts by mass, IBXMA 26 parts by mass, V-601 5.1 parts by mass, and butyl acetate 90 parts by mass from the dropping funnel into the flask over 5 hours. After completion of the dropping, the polymerization solution was added dropwise to 6000 parts by mass of hexane, whereby the vinyl polymer in the polymerization solution was isolated to obtain a polymer A-10.
Table 1 shows the composition and analysis results of the polymer A-10.

Synthesis Example 11 (Synthesis of Polymer A-11)
A four-necked flask with an internal volume of 1 liter was charged with a mixed liquid consisting of 35 parts by mass of MMA, 5.1 parts by mass of St, 218 parts by mass of butyl acetate and 7.5 parts by mass of V-601, and this mixture was bubbled with nitrogen gas. Was sufficiently degassed, and the internal temperature of the mixed solution was raised to 90 ° C. Separately, polymerization was performed by dropping a mixed liquid consisting of MMA 158 parts by mass, St 47 parts by mass, V-601 68 parts by mass, and butyl acetate 90 parts by mass into the flask from a dropping funnel over 5 hours. After completion of the dropping, the polymerization solution was dropped into 6000 parts by mass of hexane to isolate the vinyl polymer in the polymerization solution, thereby obtaining a polymer A-11.
Table 1 shows the composition and analysis results of the polymer A-11.

Synthesis Example 12 (Synthesis of Polymer A-12)
A four-necked flask with an internal volume of 1 liter is charged with a mixed liquid consisting of 50 parts by mass of MMA, 227 parts by mass of butyl acetate, and 12 parts by mass of V-601. The mixed liquid is sufficiently deaerated by bubbling with nitrogen gas and mixed. The internal temperature of the liquid was raised to 90 ° C. Separately, polymerization was carried out by dropping a mixed liquid consisting of 200 parts by mass of MMA, 46 parts by mass of V-601 and 90 parts by mass of butyl acetate into the flask from a dropping funnel over 5 hours. After completion of the dropping, the polymerization solution was added dropwise to 6000 parts by mass of hexane, whereby the vinyl polymer in the polymerization solution was isolated to obtain a polymer A-12.
The composition and analysis results of polymer A-12 are shown in Table 1.

Synthesis Example 13 (Synthesis of Polymer A-13)
A four-necked flask with an internal volume of 1 liter is charged with a mixed liquid consisting of 221 parts by mass of butyl acetate and 3.2 parts by mass of V-601, and the mixed liquid is sufficiently degassed by bubbling with nitrogen gas. The internal temperature was raised to 90 ° C. Separately, a mixed liquid consisting of 34 parts by mass of MMA, 215 parts by mass of butyl methacrylate (hereinafter referred to as “BMA”), 60 parts by mass of V-601 and 90 parts by mass of butyl acetate is dropped into the flask from the dropping funnel over 5 hours. Polymerization was carried out. After completion of the dropwise addition, the polymerization solution was dropped into a mixed solution consisting of 4200 parts by mass of methanol and 1800 parts by mass of distilled water, whereby the vinyl polymer in the polymerization solution was isolated to obtain a polymer A-13.
Table 1 shows the composition and analysis results of the polymer A-13.

Synthesis Example 14 (Synthesis of Polymer A-14)
A four-necked flask with an internal volume of 1 liter is charged with a mixed liquid consisting of 232 parts by mass of butyl acetate and 2.5 parts by mass of V-601, and the mixed liquid is sufficiently degassed by bubbling with nitrogen gas. The internal temperature was increased to 90 ° C. Separately, 194 parts by mass of t-butyl methacrylate (hereinafter referred to as “tBMA”), 43 parts by mass of ethyl acrylate (hereinafter referred to as “EA”), 11 mass of 2-hydroxyethyl methacrylate (hereinafter referred to as “2HEMA”) Polymerization was carried out by dropping a mixed liquid consisting of 47 parts by mass, V-601 and 90 parts by mass of butyl acetate into the flask from a dropping funnel over 5 hours. After completion of the dropping, the polymerization solution was dropped into a mixed solution consisting of 4200 parts by mass of methanol and 1800 parts by mass of distilled water, whereby the vinyl polymer in the polymerization solution was isolated to obtain a polymer A-14.
The composition and analysis results of the polymer A-14 are shown in Table 1.

Synthesis Example 15 (Synthesis of Polymer A-15)
In a four-necked flask with an internal volume of 1 liter, a mixed liquid consisting of 33 parts by mass of MMA, 15 parts by mass of cyclohexyl methacrylate (hereinafter referred to as “CHMA”), 230 parts by mass of butyl acetate and 4.0 parts by mass of V-601 is added. The mixture was sufficiently deaerated by bubbling nitrogen gas, and the internal temperature of the mixture was increased to 90 ° C. Separately, polymerization was performed by dropping a mixed liquid consisting of 132 parts by mass of MMA, 62 parts by mass of CHMA, 30 parts by mass of V-601, and 90 parts by mass of butyl acetate into the flask from a dropping funnel over 5 hours. After completion of the dropping, the polymerization solution was dropped into a mixed solution consisting of 4800 parts by mass of methanol and 1200 parts by mass of distilled water, thereby isolating the vinyl polymer in the polymerization solution to obtain a polymer A-15.
Table 1 shows the composition and analysis results of the polymer A-15.

Synthesis Example 16 (Synthesis of Polymer A-16)
A four-necked flask with an internal volume of 1 liter is charged with a mixed liquid consisting of 135 parts by mass of butyl acetate and 2.2 parts by mass of V-601, and the mixed liquid is sufficiently degassed by bubbling with nitrogen gas. The internal temperature was increased to 90 ° C. Separately, polymerization was carried out by dropping a mixed liquid consisting of 100 parts by mass of MMA, 79 parts by mass of DCP, 41 parts by mass of V-601, and 90 parts by mass of butyl acetate into the flask from a dropping funnel over 5 hours. After completion of the dropping, the polymerization solution was dropped into a mixed solution consisting of 4800 parts by mass of methanol and 1200 parts by mass of distilled water, whereby the vinyl polymer in the polymerization solution was isolated to obtain a polymer A-16.
Table 1 shows the composition and analysis results of the polymer A-16.

Synthesis Example 17 (Synthesis of Polymer A-17)
A four-necked flask with an internal volume of 1 liter is charged with a mixed liquid consisting of 90 parts by mass of butyl acetate and 1.7 parts by mass of V-601, and the mixed liquid is sufficiently degassed by bubbling with nitrogen gas. The internal temperature was increased to 90 ° C. Separately, a mixed solution consisting of 80 parts by mass of MMA, 63 parts by mass of methacrylic acid-1-adamantyl (hereinafter referred to as “ADMA”), 33 parts by mass of V-601, and 90 parts by mass of butyl acetate was added from the dropping funnel into the flask for 5 hours. The polymerization was carried out by dropwise addition. After completion of the dropping, the polymerization solution was dropped into a mixed solution consisting of 4800 parts by mass of methanol and 1200 parts by mass of distilled water, whereby the vinyl polymer in the polymerization solution was isolated to obtain a polymer A-17.
Table 1 shows the composition and analysis results of the polymer A-17.

2. Synthesis Synthesis Example 18 of Acrylic Adhesive Polymer (Synthesis of Polymer B-1)
Into a four-necked flask with an internal volume of 1 liter, 230 parts by mass of ethyl acetate was charged, this mixed solution was sufficiently deaerated by bubbling with nitrogen gas, and the internal temperature of the mixed solution was raised to 70 ° C. Separately, 80 parts by mass of methoxyethyl acrylate (hereinafter referred to as “MEA”), 15 parts by mass of butyl acrylate (hereinafter referred to as “BA”), 5 parts by mass of 2-hydroxyethyl acrylate (hereinafter referred to as “HEA”) Polymerization was carried out by dropping a mixed solution consisting of 1 part by mass of azobisisobutyronitrile (hereinafter referred to as “AIBN”) from the dropping funnel into the flask over 4 hours. After completion of the dropwise addition, 0.3 part of AIBN was further added and aged at 70 ° C. for 3 hours, and the solid content concentration was adjusted to 30% by mass with ethyl acetate to obtain a polymer B-1 solution. Obtained polymer B-1 consisted of MEA 80 mass%, BA 15 mass%, HEA 5 mass%, and was Mw 500,000, Mn 50,000, and Mw / Mn 10.0.

Synthesis Example 19 (Synthesis of polymer B-2)
Into a four-necked flask with an internal volume of 1 liter, 230 parts by mass of ethyl acetate was charged, this mixed solution was sufficiently deaerated by bubbling with nitrogen gas, and the internal temperature of the mixed solution was raised to 70 ° C. Separately, polymerization was performed by dropping a mixed liquid consisting of 50 parts by mass of MEA, 45 parts by mass of BA, 5 parts by mass of HEA, and 1 part by mass of AIBN into the flask from a dropping funnel over 4 hours. After completion of the dropwise addition, 0.3 part of AIBN was further added and aged at 70 ° C. for 3 hours, and the solid content concentration was adjusted to 30% by mass with ethyl acetate to obtain a polymer B-2 solution. The obtained polymer B-2 was composed of 50% by mass of MEA, 45% by mass of BA, and 5% by mass of HEA, and was Mw 500,000, Mn 50,000, and Mw / Mn 10.0.

Synthesis Example 20 (Synthesis of polymer B-3)
Into a four-necked flask with an internal volume of 1 liter, 230 parts by mass of ethyl acetate was charged, this mixed solution was sufficiently deaerated by bubbling with nitrogen gas, and the internal temperature of the mixed solution was raised to 70 ° C. Separately, polymerization was carried out by dropping a mixed liquid consisting of 97 parts by mass of BA, 3 parts by mass of HEA, and 1 part by mass of AIBN from the dropping funnel into the flask over 4 hours. After completion of the dropwise addition, 0.3 part of AIBN was further added and aged at 70 ° C. for 3 hours, and the solid content concentration was adjusted to 30% by mass with ethyl acetate to obtain a polymer B-2 solution. The obtained polymer B-3 was composed of 97% by mass of BA and 3% by mass of HEA, and had Mw of 500,000, Mn of 50,000, and Mw / Mn of 10.0.

3. Production and evaluation of pressure-sensitive adhesive composition Example 1
The polymer (A-1) obtained in Synthesis Example 1 was dissolved in ethyl acetate to prepare a polymer (A-1) solution having a solid content concentration of 30% by mass. 10 parts by mass of the polymer (A-1) solution, 100 parts by mass of the polymer B-1 solution, and 0.27 parts by mass of Coronate L45 (manufactured by Nippon Polyurethane Industry Co., Ltd.) as a crosslinking agent are mixed to obtain a pressure-sensitive adhesive composition. It was.

  This pressure-sensitive adhesive composition was applied on a 38 μm thick polyethylene terephthalate (hereinafter “PET”) separator so that the thickness after drying was 50 μm. By drying the pressure-sensitive adhesive composition at 80 ° C. for 4 minutes, ethyl acetate was removed and a crosslinking reaction was performed, and a PET separator having a thickness of 38 μm different from that of the separator was bonded, and 5 ° C. at 5 ° C. It left still for one day and obtained the adhesive film sample with a double-sided separator.

  The obtained adhesive film sample was subjected to various measurements and evaluations by the following methods. The obtained results are shown in Table 2.

<Gel fraction>
0.2 g of adhesive was collected from the adhesive film sample, and the initial weight of the adhesive was weighed. The adhesive is immersed in 50 g of ethyl acetate and allowed to stand at room temperature for 16 hours. Thereafter, the mixture was filtered through a 200 mesh wire mesh, and the residue remaining on the mesh was dried at 80 ° C. for 3 hours and weighed. The gel fraction was calculated from the initial weight and the remaining weight.

<Adhesive strength to polycarbonate (PC) and polymethyl methacrylate (PMMA)>
The pressure-sensitive adhesive film sample was transferred to a PET film (100 μm) subjected to easy adhesion treatment to obtain a pressure-sensitive adhesive sheet for evaluation. The adherend is a polycarbonate plate (Mitsubishi Gas Chemical Co., Ltd., Iupilon NF-2000) or a polymethylmethacrylate plate (Mitsubishi Rayon Co., Ltd., Acrylite L001), and tabletop pressure deaerator TBR-200 (Chiyoda Electric Co., Ltd.). ) For 20 minutes under conditions of 0.5 MPa and 50 ° C., and then, using a tensile tester with a thermostatic bath, Strograph R type (manufactured by Toyo Seiki Co., Ltd.) under the conditions of 60 ° C. and 85 ° C. According to Z-0237 “Testing method of adhesive tape / adhesive sheet”, the 180-degree peel strength of the adhesive sheet was measured and used as the adhesive strength.

<Adhesive strength to COP>
The pressure-sensitive adhesive film sample was transferred to a PET film (100 μm) subjected to easy adhesion treatment to obtain a pressure-sensitive adhesive sheet for evaluation. A COP film (Zeonor ZF-14 100 μm, manufactured by Nippon Zeon Co., Ltd.) is attached to a polymethyl methacrylate plate to form an adherend, and JIS Z-0237 “Testing method for adhesive tape / adhesive sheet” under conditions of 23 ° C. and 50% RH. The 180 degree peel strength of the pressure-sensitive adhesive sheet was measured according to the above, and used as the adhesive strength. The peeling speed is 300 mm / min. 30 mm / min. And 3 mm / min. It was set as three levels.

<Storage elastic modulus at 25 ° C.>
A 1 mm thick adhesive film was prepared by laminating 20 adhesive film samples, and viscoelasticity measurement was performed under the following conditions.
Apparatus: Rheological Instrument A. B. VISCOANALYZER VAR100 made by company
Frequency: 1Hz
Distortion: 0.1%
Geometry: 6mmφ parallel plate

<Step following capability>
Create a laminate with an easy-adhesive PET film attached to one side of an adhesive film sample and a polycarbonate plate (Mitsubishi Gas Chemical Co., Ltd., Iupilon NF-2000) printed with a 20 μm thick step on the other side. did. The laminate was subjected to a pressure bonding treatment at 50 ° C., 0.5 MPa, for 20 minutes, and then visually observed for the presence or absence of bubbles around the printed portion, thereby evaluating the step following ability. A sample having no bubbles was marked with ◯, and a sample with bubbles was marked with ×.

<Tg of the surface layer portion of the pressure-sensitive adhesive layer>
From the area ratio of C1s and O1s measured by X-ray photoelectron spectrometer (XPS) of the adhesive film sample, the mass ratio of the vinyl polymer (A) and the acrylic adhesive polymer (B) on the surface from the surface to about 5 nm is calculated. Calculated.
XPS measurement was performed under the following conditions.
Apparatus: PHI5000 VersaProbe manufactured by ULVAC-PHI
X-ray: Al-Kα (1486.6 eV)
X-ray incident angle on sample: 0 ° (angle with respect to normal of sample measurement surface)
Photoelectron detection angle: 45 ° (angle with respect to normal of sample measurement surface)

Next, the surface Tg was calculated from the surface composition obtained in the measurement according to the following FOX equation.
1 / [Tg of surface layer] (K) = W _A / Tg _A + W _B / Tg _B
here,
W _A : Weight fraction of vinyl polymer (A) Tg _A : Tg of vinyl polymer (A)
W _B : Weight fraction of acrylic adhesive polymer (B) Tg _B : Tg of acrylic adhesive polymer (B)

<Durability>
A laminated film in which a PET film subjected to easy adhesion treatment is pasted on one side of an adhesive film sample and a polycarbonate plate or a polymethyl methacrylate plate is pasted on the other side is prepared, and the laminated body is 50 ° C., 0.5 MPa, 20 minutes. The crimping process was performed. After that, the laminated body was subjected to a load for 24 hours with an 85 ° C. blown dryer or a 60 ° C./95% RH, 85 ° C./85% constant temperature and humidity chamber, and the appearance after the load (whether foaming was present) was visually confirmed. And evaluated according to the following criteria.
○: No change in appearance △: Area of the foamed portion is 10% or less with respect to the area of the test piece ×: Area of the foamed portion exceeds 10% with respect to the area of the test piece

<Compatibility of vinyl polymer (A) and acrylic adhesive polymer (B)>
A pressure-sensitive adhesive composition was prepared by mixing 1 part by mass and 10 parts by mass of a vinyl polymer (A) and an acrylic adhesive polymer (B) each having a solid content adjusted to 30% by mass with ethyl acetate. Next, an appropriate amount of the pressure-sensitive adhesive composition was dropped on a release paper, and left at 80 ° C. for 15 hours to remove ethyl acetate, thereby obtaining a dried product of the pressure-sensitive adhesive composition. Separately, two glass plates with a thickness of 1 mm were prepared, and the thickness of the pressure-sensitive adhesive layer was obtained by sandwiching the dried product of the pressure-sensitive adhesive composition with the two glass plates through a spacer made of a 300 μm-thick aluminum film. A laminate having a thickness of 300 μm was obtained. The obtained laminate was allowed to stand at 23 ° C. and 50% RH for 1 day, and then measured for haze value using a Nippon Denshoku haze meter “Haze Meter NDH2000” (model name). The solubility was evaluated.

Examples 2 to 11, Reference Example 1 and Comparative Examples 1 to 12
In Example 1, the types and ratios of the acrylic tacky polymer and tackifier were changed as shown in Tables 2 to 5 to obtain pressure-sensitive adhesive compositions, and the same measurements as in Example 1 were performed. The results are shown in Tables 2-5.

Details of the compounds used in Table 1 are shown below.
IBXMA: isobornyl methacrylate DCP: dicyclopentanyl methacrylate ADMA: 1-adamantyl methacrylate CHMA: cyclohexyl methacrylate MMA: methyl methacrylate St: styrene BMA: butyl methacrylate tBMA: t-butyl methacrylate EA: acrylic acid Ethyl 2HEMA: 2-hydroxyethyl methacrylate

Examples 1 to 11 using the pressure-sensitive adhesive composition of the present invention showed good transparency and step following property and adhesive strength under a condition of 60 ° C. of 3.0 N / 25 mm or more. In addition, the laminates using PC and PMMA obtained by using these pressure-sensitive adhesive compositions as a substrate float the pressure-sensitive adhesive sheet even after being exposed to high temperature and high humidity conditions of 60 ° C. and 95% RH for 24 hours. No peeling was observed and the durability was excellent. Furthermore, the adhesive strength to COP was also high, and it was confirmed that the adhesiveness excellent also with respect to the olefin type adherend was shown.
Among them, Examples 1 to 3 and 5 to 11 show an adhesive strength of 3.0 N / 25 mm or more even under 85 ° C. conditions, and the durability test was performed under extremely severe conditions of 85 ° C. However, it was confirmed that good results were shown.

Comparative Examples 1 to 3 are various acrylic adhesive polymers used alone, and Comparative Examples 4 to 12 are experimental examples of adhesive compositions containing various vinyl polymers. The adhesive strength was less than 3.0 N / 25 mm, resulting in poor durability. Regarding all the comparative examples, the adhesive strength to COP was low particularly at low speed peeling, and did not show sufficient adhesiveness.
Comparative Example 12 is an experimental example corresponding to Example 1 described in Patent Document 4, but the durability when using the plastic substrate, which is the subject of the present invention, was insufficient.

The pressure-sensitive adhesive composition of the present invention can be suitably used for various general pressure-sensitive processed products such as pressure-sensitive adhesive films, pressure-sensitive adhesive sheets, pressure-sensitive adhesive tapes and labels. Specific examples of the adhesive processed product include an adhesive sheet, an adhesive film, an adhesive tape, a pressure sensitive tape, a surface protective film, a surface protective tape, a masking tape, an electrical insulating tape, and a laminate.
In addition to the above, the pressure-sensitive adhesive composition of the present invention has excellent transparency and wet heat whitening resistance, and has high adhesive strength and tack to various adherends such as glass and plastic. It is also suitable for bonding displays such as display devices, organic EL display devices, plasma display panels, and various optical films used in these displays.

Claims (5)

Glass transition temperature (Tg) of 30 to 150 ° C., a vinyl polymer a number average molecular weight of 500 to 10,000 (A), A acrylic-based adhesive polymer (B) and an adhesive composition containing a crosslinking agent There,
The vinyl polymer (A) includes, as monomers constituting the vinyl polymer (A), isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, cyclohexyl (meth) acrylate, (meta ) Containing one or more vinyl monomers selected from adamantyl acrylate and methyl (meth) acrylate in a range of 10 to 100% by mass;
The acrylic pressure-sensitive adhesive polymer (B) contains an alkoxyalkyl (meth) acrylate in the range of 30 to 99% by mass in all constituent monomers.
The proportion of the acrylic adhesive polymer (B) the vinyl polymer to 100 parts by weight (A) is 0.5 to 60 parts by weight,
The ratio of the crosslinking agent to 100 parts by mass of the acrylic adhesive polymer (B) is 0.01 to 10 parts by mass,
Tg of the adhesive composition is the -80 to -10 ° C.,
The adhesive strength of a pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer having a film thickness of 50 μm made of the pressure-sensitive adhesive composition on a 100 μm-thick polyethylene terephthalate film substrate at 60 ° C. and a peeling rate of 30 mm / min. 3.0N / 25mm or more der is,
The vinyl polymer (A) is partially segregated on the surface layer in the pressure-sensitive adhesive layer obtained by applying the pressure-sensitive adhesive composition to the separator, then drying and crosslinking reaction, so that X-rays of the pressure-sensitive adhesive layer can be obtained. A pressure-sensitive adhesive composition, wherein Tg calculated from the composition of the surface layer portion obtained by photoelectron spectroscopic analysis is 30 ° C. or more higher than Tg of the pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition according to claim 1, comprising an aromatic vinyl compound in a monomer constituting the vinyl polymer (A). The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the acrylic adhesive polymer (B) has a weight average molecular weight of 100,000 or more and 2,000,000 or less. Coating a separator for pressure-sensitive adhesive composition according to any one of claims 1 to 3, the manufacturing method of the pressure-sensitive adhesive sheet comprising a dry Ru bonded to the substrate on one surface of the resulting adhesive layer process. Including coating a separator for pressure-sensitive adhesive composition according to any one of claims 1 to 3, Ru bonded to one side or the glass plate and / or transparent plastic plate on both sides of the dried resultant pressure-sensitive adhesive layer step Manufacturing method for adhesive processed products.