WO2016199787A1 - Adhesive composition and method for producing same, and adhesive product - Google Patents

Abstract

This adhesive composition is characterized by containing a vinyl polymer(A) having a Tg of 40-200°C and a number average molecular weight of 500-10,000, and an acrylic adhesive polymer (B), wherein the acrylic adhesive polymer (B) contains a structural unit derived from (meth)acrylic acid alkoxyalkyl ester by 85 mass% or more with respect to all structural units, the ratio of the vinyl polymer(A) with respect to 100 parts by mass of the acrylic adhesive polymer (B) is 0.5-30 parts by mass, and, when an adhesive layer is obtained by coating the adhesive composition on a separator and drying the adhesive composition, the Tg calculated from a chemical composition which is of the outer layer portion of the adhesive layer and which is obtained through X-ray photoelectron spectroscopic analysis of the adhesive layer is at least 30°C higher than the Tg of the adhesive composition.

Description

Adhesive composition and method for producing the same, and adhesive product

The present invention relates to an adhesive composition and a method for producing the same. More specifically, the present invention relates to a pressure-sensitive adhesive composition excellent in transparency and adhesion performance to various adherends, a method for producing the same, and a pressure-sensitive adhesive product using the same.

(Cross-reference of related applications)
This application claims priority based on Japanese Patent Application No. 2015-118857, filed on June 12, 2015, the entire contents of which are incorporated herein by reference. And

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. .

For the above-mentioned problems, by using a pressure-sensitive adhesive having a high storage elastic modulus, a method of sticking a pressure-sensitive adhesive layer having high adhesive strength and excellent shape stability to a substrate and suppressing floating and peeling. Have been disclosed. However, when such a pressure-sensitive adhesive is used for bonding a surface having a stepped shape or a concavo-convex shape, it cannot sufficiently follow the concavo-convex shape or the like of the adhesive surface, and a void is generated on the end surface of the concavo-convex portion or the like. There was a case. For this reason, various adhesive compositions based on an adhesive polymer having excellent flexibility have been proposed.
Patent Document 1 discloses a pressure-sensitive adhesive composition containing a high molecular weight (meth) acrylic acid ester polymer and a low molecular weight (meth) acrylic acid ester polymer, which can form a pseudo cross-linked structure. Yes. Patent Document 2 describes a pressure-sensitive adhesive composition for a polarizing plate comprising specific (meth) acrylic copolymers having different molecular weights, a tolylene diisocyanate isocyanate compound and a silane coupling agent.
Patent Document 3 includes 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 pressure-sensitive adhesive composition has a good performance balance such as durability, adhesiveness, step following property, corrosiveness, and transparency. Patent Document 4 discloses a pressure-sensitive adhesive polymer mainly composed of (meth) acrylic acid alkoxyalkyl ester, a specific low molecular weight polymer containing an amino group-containing monomer or an amide group-containing monomer as a constituent monomer, a crosslinking agent, Is disclosed, and is shown to be effective in suppressing foaming under a high-temperature and high-humidity atmosphere and restoring whitening due to moisture intrusion into the pressure-sensitive adhesive layer.
Furthermore, Patent Document 5 discloses a pressure-sensitive adhesive composition containing a specific low molecular weight vinyl polymer and an acrylic pressure-sensitive adhesive polymer and having excellent adhesive strength to polycarbonate and polymethylmethacrylate plates.

JP 2012-41453 A JP 2011-232470 A JP 2011-162593 A JP 2002-327160 A JP 2014-88549 A

The pressure-sensitive adhesive compositions described in Patent Documents 1 to 3 are effective in preventing floating and peeling due to differences in thermal shrinkage from the base material, but outgassing from a plastic substrate under high temperature and high humidity conditions. The floating and peeling due to the occurrence cannot be sufficiently suppressed. The pressure-sensitive adhesive compositions described in Patent Documents 4 and 5 have improved performance for suppressing foaming caused by outgas when a plastic substrate is used. However, depending on the combination of the adhesive polymer and the low molecular weight polymer, further improvement in durability and the like is desired.
In recent years, development of products with excellent design has progressed, and terminals having various shapes are distributed in the market. Under such circumstances, there is an increasing demand for adhesives to improve the adhesion to curved surfaces, but the above-mentioned patent documents do not show specific effects on curved surface adhesion.

This specification shows sufficient transparency and good adhesion to various adherends, has durability to suppress foaming caused by outgas in use under high temperature and high humidity conditions, and also has curved surface adhesion. An excellent pressure-sensitive adhesive composition and a method for producing the same, and a pressure-sensitive adhesive product using the pressure-sensitive adhesive composition are provided.

As a result of intensive studies in view of the above problems, the present inventor has focused on a specific pressure-sensitive adhesive composition containing an acrylic pressure-sensitive adhesive polymer and a low molecular weight vinyl polymer. That is, when forming a pressure-sensitive adhesive layer with a pressure-sensitive adhesive composition containing a predetermined acrylic pressure-sensitive adhesive polymer and a vinyl polymer having a predetermined molecular weight range, the low molecular weight vinyl polymer is formed on the surface of the pressure-sensitive adhesive layer. I have learned that segregation is possible. In addition, it is known that this pressure-sensitive adhesive composition is effective in suppressing foaming derived from the outgas under high temperature and high humidity, and exhibits excellent curved surface adhesiveness, and provides the following means.

Means provided by the present specification are as follows.
[1] An adhesive composition containing a vinyl polymer (A) having a glass transition temperature (Tg) of 40 ° C. or higher and 200 ° C. or lower and a number average molecular weight of 500 to 10,000, and an acrylic adhesive polymer (B) A thing,
The acrylic adhesive polymer (B) contains 85% by mass or more of a structural unit derived from an alkoxyalkyl ester of (meth) acrylic acid with respect to the entire structural unit,
The ratio of the vinyl polymer (A) to 100 parts by mass of the acrylic adhesive polymer (B) is 0.5 parts by mass or more and 30 parts by mass or less.
When the pressure-sensitive adhesive composition is applied to a separator and dried to obtain a pressure-sensitive adhesive layer, Tg calculated from the composition of the surface layer portion obtained by X-ray photoelectron spectroscopy of the pressure-sensitive adhesive layer is the pressure-sensitive adhesive. A pressure-sensitive adhesive composition characterized by being 30 ° C. or more higher than the Tg of the entire layer.
[2] The above-mentioned [1], wherein the vinyl polymer (A) has a structural unit derived from at least one monomer selected from the group consisting of an aliphatic cyclic vinyl compound and an aromatic vinyl compound. Adhesive composition.
[3] The adhesive strength of a pressure-sensitive adhesive sheet provided with a 100 μm-thick polyethylene terephthalate film base material with a pressure-sensitive adhesive layer made of the above-mentioned pressure-sensitive adhesive composition on a polycarbonate terephthalate film substrate at 85 ° C. is 15 N / 25 mm or more. ] Or the pressure-sensitive adhesive composition according to [2].
[4] The adhesive strength of a pressure-sensitive adhesive sheet provided with a 100 μm-thick polyethylene terephthalate film base material with a 50 μm-thick pressure-sensitive adhesive layer comprising the above-mentioned pressure-sensitive adhesive composition is 5.0 N / 25 mm or more at 85 ° C. The pressure-sensitive adhesive composition according to [1] or [2].
[5] A method for producing a pressure-sensitive adhesive composition,
The glass transition temperature (Tg) is 40 ° C. or higher and 200 ° C. or lower and the number average molecular weight with respect to 100 parts by mass of the acrylic adhesive polymer (B) containing 85% by mass or more of the structural unit derived from (meth) acrylic acid alkoxyester. When blending 0.5 parts by weight or more and 30 parts by weight or less of the vinyl polymer (A) having a molecular weight of 500 to 10,000,
Tg calculated from the composition of the surface layer portion obtained by X-ray photoelectron spectroscopy analysis of the pressure-sensitive adhesive layer obtained by applying the pressure-sensitive adhesive composition to the separator and drying is 30 ° C. than the Tg of the whole pressure-sensitive adhesive layer. The method for producing a pressure-sensitive adhesive composition, wherein the vinyl polymer (A) and the acrylic pressure-sensitive adhesive polymer (B) are selected and blended so as to be higher.
[6] A pressure-sensitive adhesive sheet or pressure-sensitive adhesive tape in which a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to any one of [1] to [4] is provided on one side or both sides of a substrate.
[7] An adhesive product obtained by bonding a glass plate and / or a transparent plastic plate to one or both sides of an adhesive layer formed from the adhesive composition according to any one of [1] to [4].
[8] An adhesive product comprising an adhesive layer,
The pressure-sensitive adhesive layer contains a vinyl polymer (A) having a glass transition temperature (Tg) of 40 ° C. or higher and 200 ° C. or lower and a number average molecular weight of 500 to 10,000 and an acrylic pressure-sensitive adhesive polymer (B),
The acrylic adhesive polymer (B) contains 85% by mass or more of a structural unit derived from an alkoxyalkyl ester of (meth) acrylic acid with respect to the entire structural unit,
The ratio of the vinyl polymer (A) to 100 parts by mass of the acrylic adhesive polymer (B) is 0.5 parts by mass or more and 30 parts by mass or less.
The pressure-sensitive adhesive product containing the vinyl polymer (A) at a higher concentration on at least one surface layer side facing in the thickness direction in the pressure-sensitive adhesive layer.
[9] The pressure-sensitive adhesive product according to [8], wherein Tg calculated from the composition of the surface layer portion obtained by X-ray photoelectron spectroscopy of the pressure-sensitive adhesive layer is 30 ° C. or more higher than Tg of the whole pressure-sensitive adhesive layer. .

According to the pressure-sensitive adhesive composition disclosed herein (hereinafter also referred to as the pressure-sensitive adhesive composition), a pressure-sensitive adhesive product that exhibits sufficient transparency and good adhesion to various adherends can be obtained. it can. In addition, the adhesive product can suppress foaming from outgas even when used under high-temperature and high-humidity conditions, eliminating problems such as reduced visibility due to swelling and peeling of the adhesive product. In addition, it has excellent curved surface adhesion.

The present specification is a specific pressure-sensitive adhesive composition containing a predetermined vinyl polymer and an acrylic pressure-sensitive adhesive polymer, respectively, which is obtained by X-ray photoelectron spectroscopy analysis of a pressure-sensitive adhesive layer formed from the composition. The Tg calculated from the composition of the surface layer part is 30 ° C. or more higher than the Tg of the entire pressure-sensitive adhesive layer, a method for producing the same, and a pressure-sensitive adhesive product using the pressure-sensitive adhesive composition .

This pressure-sensitive adhesive composition comprises a vinyl polymer (A) having a certain glass transition temperature and a number average molecular weight, and an acrylic pressure-sensitive adhesive polymer having a structural unit derived from an alkoxyalkyl ester (meth) acrylate of 85% by mass or more ( By combining B) with a certain ratio, the vinyl polymer (A) can be segregated on the surface layer of the pressure-sensitive adhesive layer when forming the pressure-sensitive adhesive layer. The segregation behavior of the vinyl polymer (A) is based on the fact that the specific vinyl polymer (A) and the acrylic adhesive polymer (B) are not completely compatible but not completely phase separated. . The segregation behavior is based on the fact that the vinyl polymer (A) has at least a lower polarity than the acrylic adhesive polymer (B).

As described above, a vinyl polymer (A) that is not completely compatible with the acrylic adhesive polymer (B) is used for the present adhesive composition. At this time, the degree of segregation can be adjusted by appropriately adjusting the amount of the vinyl polymer (A) used in the pressure-sensitive adhesive composition. If the amount of the vinyl polymer (A) used is too small, segregation on the surface of the pressure-sensitive adhesive layer becomes insufficient, and a sufficient effect may not be obtained. On the other hand, when there is too much usage-amount of a vinyl polymer (A), as a result of phase-separating with an acrylic adhesive polymer (B), there exists a tendency for transparency and adhesive performance of an adhesive layer to fall. In addition, the glass transition temperature of the surface portion of the pressure-sensitive adhesive layer can be adjusted by appropriately adjusting the glass transition temperature of the vinyl polymer (A).

The segregation of the vinyl polymer (A) occurs at the time of forming the pressure-sensitive adhesive layer, and the vinyl polymer (A) is segregated on the interface side having a low surface energy. Therefore, for example, when two surface layers opposed in the thickness direction in the sheet-like or film-like pressure-sensitive adhesive layer of the present pressure-sensitive adhesive composition are in contact with a substance having a low surface energy such as a gas or a certain solid, such a substance. Pressure-sensitive adhesive layer containing vinyl polymer (A) at a higher concentration on the low surface energy interface side in contact with the pressure-sensitive adhesive layer while containing vinyl polymer (A) at a lower concentration on the central side in the thickness direction of the pressure-sensitive adhesive layer Can be obtained. That is, a pressure-sensitive adhesive layer having a gradient composition having a higher concentration of the vinyl polymer (A) on the surface layer side of the pressure-sensitive adhesive can be obtained. From the viewpoint of the acrylic pressure-sensitive adhesive polymer (B), a pressure-sensitive adhesive layer having a gradient composition having the acrylic pressure-sensitive adhesive polymer (B) at a lower concentration on the surface layer side of the pressure-sensitive adhesive layer can be obtained.

For example, when only one surface of the two surface layers opposed in the thickness direction in the sheet-like or film-like pressure-sensitive adhesive layer of the present pressure-sensitive adhesive composition is the low surface energy interface side, A pressure-sensitive adhesive layer containing the coalescence (A) at a higher concentration can be obtained.

As for this adhesive composition, Tg calculated from the composition of the surface layer part obtained by the X-ray photoelectron spectroscopy analysis of an adhesive layer as a result of segregation of the vinyl polymer (A) in an adhesive layer is the whole adhesive layer. It can be made 30 ° C. or higher than the Tg. Thereby, the adhesive characteristic of an adhesive layer can be controlled and favorable adhesive strength can be obtained. That is, since a relatively high Tg is provided in the vicinity of the adhesive interface constituted by the surface layer of the pressure-sensitive adhesive, it is possible to exhibit good adhesiveness that has not been achieved in the past. For example, even if there is outgas from the adherend at high temperatures, the pressure-sensitive adhesive layer can be prevented from floating and peeling off, and good durability can be exhibited. Moreover, the whole adhesive layer can have favorable followable | trackability with respect to a to-be-adhered body.

Hereinafter, the disclosure of this specification will be described in detail. In the present specification, “(meth) acryl” means acryl and / or methacryl, and “(meth) acrylate” means acrylate and / or methacrylate. The “(meth) acryloyl group” means an acryloyl group and / or a methacryloyl group.

This pressure-sensitive adhesive composition contains a vinyl polymer (A) and an acrylic pressure-sensitive adhesive 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 40 ° C. or higher and 200 ° C. or lower. The lower limit of Tg can be 50 ° C. or higher and 60 ° C. or higher. Moreover, an upper limit can also be 180 degrees C or less, 150 degrees C or less, and 120 degrees C or less. Furthermore, it can also be set to 100 ° C. or lower. Moreover, the range of Tg can also be 60 to 180 degreeC and 60 to 150 degreeC. 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 the Tg is less than 40 ° C., the adhesive strength to various adherends may not be sufficient and the durability may be poor. Moreover, generally 200 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 acid ester compounds, aliphatic cyclic vinyl compounds. , Aromatic vinyl compound, unsaturated carboxylic acid, unsaturated acid anhydride, hydroxyl group-containing vinyl compound, amino group-containing vinyl compound, amide group-containing vinyl compound, alkoxy group-containing vinyl compound, cyano group-containing vinyl compound, nitrile group-containing Examples include vinyl compounds and maleimide compounds. These compounds may be used alone or in combination of two or more.
Among these, an aliphatic cyclic vinyl compound and an aromatic vinyl compound tend to provide good adhesive performance in the adhesive layer. By using these vinyl compounds, it becomes easy to obtain a vinyl polymer (A) having a relatively low polarity with respect to the adhesive polymer (B), and the vinyl polymer (A) is formed when the pressure-sensitive adhesive layer is formed. This is because it can be easily segregated to the surface layer. Therefore, the vinyl polymer (A) can also have a structural unit derived from at least one monomer selected from the group consisting of an aliphatic cyclic vinyl compound and an aromatic vinyl compound. Although the specific usage-amount of the at least 1 sort (s) of monomer chosen from the group which consists of the said aliphatic cyclic vinyl compound and an aromatic vinyl compound can be set suitably, For example, the minimum is 3 mass% or more. It can also be made 5 mass% or more and 10 mass% or more. Moreover, the upper limit can also be made into 80 mass% or less, 60 mass% or less, 50 mass% or less, for example. Further, for example, the amount used can be 3% by mass to 80% by mass, 5% by mass to 60% by mass, and can be 10% by mass to 50% by mass.

Examples of the (meth) acrylate compound include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, Isobutyl (meth) acrylate, tert-butyl (meth) acrylate, amyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, Examples thereof include linear or branched alkyl group-containing (meth) acrylic acid ester compounds such as (meth) acrylic acid n-dodecyl and (meth) acrylic acid n-octadecyl. These compounds may be used alone or in combination of two or more. For example, methyl (meth) acrylate can also be used.

Examples of the aliphatic cyclic vinyl compound include cyclohexyl (meth) acrylate, methyl cyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, isobornyl (meth) acrylate, Examples thereof include adamantyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, and the like. These compounds may be used alone or in combination of two or more.
Among these, Tg can be set relatively high, and when the pressure-sensitive adhesive layer is formed, the vinyl polymer (A) is easily segregated to the surface layer, and there is a tendency that good pressure-sensitive adhesive performance is obtained. It may also be isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, cyclohexyl (meth) acrylate and adamantyl (meth) acrylate. Especially, it can also be set as isobornyl (meth) acrylate.

Examples of the aromatic vinyl compound include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, vinyltoluene, β-methylstyrene, ethylstyrene, p-tert-butylstyrene, vinylxylene, vinylnaphthalene and the like. Can be mentioned. These compounds may be used alone or in combination of two or more. For example, styrene or the like can be used.

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 vinyl compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, (meth ) Mono (meth) acrylic acid esters of polyalkylene glycols such as 3-hydroxybutyl acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene glycol, polypropylene glycol, p-hydroxystyrene, m-hydroxystyrene, o- Examples thereof include 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 amino group-containing vinyl compounds include dimethylaminomethyl (meth) acrylate, diethylaminomethyl (meth) acrylate, 2-dimethylaminoethyl (meth) acrylate, 2-diethylaminoethyl (meth) acrylate, and (meth) acrylic. 2- (di-n-propylamino) ethyl acid, 2-dimethylaminopropyl (meth) acrylate, 2-diethylaminopropyl (meth) acrylate, 2- (di-n-propylamino) propyl (meth) acrylate , (Meth) acrylic acid 3-dimethylaminopropyl, (meth) acrylic acid 3-diethylaminopropyl, (meth) acrylic acid 3- (di-n-propylamino) propyl, and the like. These compounds may be used alone or in combination of two or more.

Examples of the amide group-containing vinyl 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 alkoxy group-containing vinyl compound include methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, n-propoxyethyl (meth) acrylate, n-butoxyethyl (meth) acrylate, and methoxy (meth) acrylate. Examples thereof include propyl, ethoxypropyl (meth) acrylate, n-propoxypropyl (meth) acrylate, and n-butoxypropyl (meth) acrylate. These compounds may be used alone or in combination of two or more.

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

Examples of the nitrile group-containing vinyl 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.

The maleimide compounds include maleimide, N-methylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-dodecylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N- (2-methylphenyl) maleimide, N Examples include-(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) can be 500 or more and 10,000 or less. The lower limit may be 1,000 or more and 1,500 or more. Further, the upper limit may be 7,000 or less, 5,000 or less, or 4,000 or less. Further, the range may be 500 or more and 7,000 or less, or 1,000 or more and 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) of the weight average molecular weight (Mw) to the above (Mn) is 3.0 or less, 2.2 or less, 1.8 or less from the viewpoint that good adhesive strength is easily obtained. You can also
Here, the number average molecular weight (Mn) and the weight average molecular weight (Mw) are standard polystyrene conversion values 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 that the vinyl polymer is well dissolved and can be easily purified, can also be used.

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, de Noyl 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 and the like 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. In addition, although a polymerization initiator may be used arbitrarily, it can also be used at about 1 mass% or less with respect to all the monomers.

[Acrylic adhesive polymer (B)]
The acrylic adhesive polymer (B) is a polymer containing a (meth) acrylic acid ester compound as a main structural unit. The glass transition temperature (Tg) may be an adhesive polymer having a range of −80 ° C. to −10 ° C. Further, it may be in the range of −70 ° C. or more and −20 ° C. or less. If Tg is −80 ° C. or higher, it has sufficient cohesive strength as a pressure-sensitive adhesive and can exhibit good curved surface adhesion. On the other hand, when Tg is −10 ° C. or lower, good performance is exhibited in terms of adhesion to the concavo-convex portion and adhesive strength under low temperature conditions.

Furthermore, the acrylic tacky polymer (B) has a weight average molecular weight (Mw) of 100,000 or more, 250,000 or more, 400,000 or more from the viewpoint of exhibiting sufficient cohesive force and good adhesiveness. It can also be.
On the other hand, if the weight average molecular weight is too high, handling in production may be difficult. Therefore, the upper limit value can be 2,000,000 or less, 1,500,000 or less, or 1,000,000 or less.

In the present specification, the acrylic pressure-sensitive adhesive polymer (B) can contain 85% by mass or more of a structural unit derived from (meth) acrylic acid alkoxyalkyl ester with respect to the entire structural unit. As a result, an acrylic pressure-sensitive adhesive polymer that is flexible and excellent in adhesiveness is obtained, and when the pressure-sensitive adhesive layer is formed from the pressure-sensitive adhesive composition containing the vinyl polymer (A), the acrylic pressure-sensitive adhesive polymer (B ) Can be made relatively low in polarity, and as a result, the vinyl polymer (A) can be segregated to the surface layer to exhibit good adhesive performance. The amount of (meth) acrylic acid alkoxyalkyl ester used may be 90% by mass or more, 92% by mass or more, or 95% by mass or more. Moreover, the upper limit of the usage-amount of the (meth) acrylic-acid alkoxyalkylester is 100 mass% or less, and may be 99.5 mass% or less, and may be 99.0 mass% or less.

Examples of the (alkyl) alkoxyalkyl ester (meth) acrylate include, for example, methoxymethyl (meth) acrylate, ethoxymethyl (meth) acrylate, butoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, and (meth) acrylic. Having an alkoxyalkyl group having 2 to 8 carbon atoms such as ethoxyethyl acrylate, butoxyethyl (meth) acrylate, methoxybutyl (meth) acrylate, ethoxybutyl (meth) acrylate and butoxybutyl (meth) acrylate (meth ) Alkoxyalkyl ester of acrylic acid and the like, and (meth) acrylic acid alkoxyalkyl ester having an alkoxyalkyl group having 2 to 4 carbon atoms is used in that segregation of the vinyl polymer (A) is likely to occur. You can also. Moreover, the (meth) acrylic-acid alkoxyalkylester can use 1 type (s) or 2 or more types of said inside.

As the acrylic adhesive polymer (B), in addition to the above (alkyl) (meth) acrylate, other monomers copolymerizable therewith can be used as long as the effects of the present invention are not impaired. Examples of the copolymerizable monomer include (meth) acrylic acid alkyl ester, polyalkylene glycol mono (meth) acrylate, and other vinyl monomers.
Examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n-butyl (meth) acrylate. , Isobutyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate , Isononyl (meth) acrylate, n-decyl (meth) acrylate, lauryl (meth) acrylate, and the like. Examples of monomers include n-butyl (meth) acrylate, (meth) acrylic acid 2 -Ethylhexyl, n-octyl (meth) acrylate, isooctyl (meth) acrylate, (meth) acrylic acid - nonyl, (meth) can be mentioned isononyl acrylate, can be used one or more of these.

Examples of the polyalkylene glycol mono (meth) acrylate include polyethylene glycol mono (meth) acrylate, methoxypolyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxypolypropylene glycol mono (meth) acrylate, polyethylene glycol- Examples thereof include polypropylene glycol mono (meth) acrylate, and one or more of these can be used.

Examples of other vinyl monomers include α, β-ethylenically unsaturated carboxylic acid monomers such as (meth) acrylic acid, itaconic acid, maleic acid and fumaric acid; styrene, α-methylstyrene, vinyltoluene Aromatic vinyl compounds such as cyclohexyl (meth) acrylate, methyl cyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, isobornyl (meth) acrylate, etc. Cyclic vinyl compound; monoalkyl ester of unsaturated dicarboxylic acid such as itaconic acid monoethyl ester, fumaric acid monobutyl ester; 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, (meth) 4-hydroxybutyl acrylate, polyethylene glycol (meth) Hydroxyl-containing monomers such as acrylate, polypropylene glycol (meth) acrylate, and polyethylene-polypropylene glycol mono (meth) acrylate; ethylenically unsaturated groups such as acrylamide, N-methylolacrylamide, N-methoxymethylacrylamide, and N-methoxybutylacrylamide Carboxylic acid amides and N-substituted compounds; unsaturated alcohols such as allyl alcohol; (meth) acrylonitrile, vinyl acetate, glycidyl (meth) acrylate, diacetone acrylamide, etc., one or more of these Can be used.
The amount of the other monomer used may be in the range of 0% by mass to 10% by mass, 0.5% by mass to 8.0% by mass, 1.0% by mass to 5.0% by mass. It can also be as follows.

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 can contain the vinyl polymer (A) and the acrylic pressure-sensitive adhesive polymer (B) at a predetermined blending ratio. Thus, when the pressure-sensitive adhesive layer is obtained from the pressure-sensitive adhesive composition, the distribution of Tg in the pressure-sensitive adhesive layer is also segregated by segregating the vinyl polymer (A) on the surface layer, and thus good adhesive strength. Can be obtained. In addition to the segregation behavior of the vinyl polymer (A), the Tg difference between the pressure-sensitive adhesive layer surface layer and the pressure-sensitive adhesive layer as described below is the ratio of the vinyl polymer (A) to the acrylic pressure-sensitive adhesive polymer (B), the vinyl weight In addition to the monomer composition (polarity) and molecular weight of the combined (A), it can be adjusted by appropriately setting Tg, Mw / Mn, and the like.

The present pressure-sensitive adhesive composition can contain 0.5 to 30 parts by mass of the vinyl polymer (A) in terms of solid content with respect to 100 parts by mass of the acrylic adhesive polymer (B). The blending ratio of the vinyl polymer to the acrylic adhesive polymer (B) is such that when the adhesive layer is obtained from the present adhesive composition, the degree of segregation of the vinyl polymer (A) and thus the Tg of the surface layer portion is the adhesive. It is appropriately set so as to be 30 ° C. or higher than the Tg of the entire layer. Although it does not specifically limit, the minimum of a vinyl polymer (A) is 0.8 mass part or more, for example, and can also be 1.0 mass part or more. Moreover, an upper limit is 20 mass parts or less, for example, and can also be 15 mass parts or less. For example, content can be 0.8 mass part or more and 20 mass parts or less, and can be 1.0 mass part or more and 15 mass parts or less. Durability is improved by using the vinyl polymer (A) in an amount of 0.5 parts by mass or more, and the effect of suppressing floating and peeling after heat and heat tends to be sufficiently expressed, and 30 parts by mass or less. Thus, the followability to the step shape can be improved. Moreover, when it exceeds 30 mass parts, it will become difficult to maintain the compatibility of a vinyl polymer (A) and an acrylic adhesive polymer (B), and it will become easy to produce phase separation.

The glass transition temperature (Tg) of the entire pressure-sensitive adhesive layer obtained from the pressure-sensitive adhesive composition is not particularly limited, but can be 0 ° C. or lower, −10 ° C. or lower, and −20 ° C. or lower. If Tg is 0 ° C. or lower, sufficient adhesive strength can be exhibited. In addition, the lower limit of Tg is −80 ° C. due to restrictions on available constituent monomers. Therefore, the Tg of the entire pressure-sensitive adhesive layer of the present invention can be in the range of −80 ° C. to 0 ° C., in the range of −80 ° C. to −10 ° C., and in the range of −70 ° C. to −20 ° C.
The glass transition temperature of the entire pressure-sensitive adhesive layer is obtained by a known method using a pressure-sensitive adhesive layer obtained from a pressure-sensitive adhesive composition containing a vinyl polymer (A) and an acrylic pressure-sensitive adhesive polymer (B) as a sample. Means the glass transition temperature.

The pressure-sensitive adhesive layer can be obtained by applying the pressure-sensitive adhesive composition to a separator and drying the composition. According to such a pressure-sensitive adhesive composition, Tg _s calculated from the composition of the surface layer portion obtained by X-ray photoelectron spectroscopy of the pressure-sensitive adhesive layer thus obtained is 30 ° C. or higher than Tg _{b of the} whole pressure-sensitive adhesive layer. Can be high. When the difference between the Tg _{s of the} surface layer part and the Tg _b of the entire pressure-sensitive adhesive layer (Tg _s −Tg _b ) is less than 30 ° C., for example, the adhesive strength under high temperature conditions of 60 ° C. or 85 ° C. is not sufficient, There is a possibility that the durability or curved surface adhesiveness which is the subject of this specification will be insufficient. The above (Tg _s -Tg _b ) may be 40 ° C. or higher and 50 ° C. or higher. The upper limit of the above (Tg _s -Tg _b ) is not particularly limited, but the upper limit is 230 ° C. from Tg that the vinyl polymer (A) and the acrylic adhesive polymer (B) can take. Is 200 ° C. or lower.

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). It is done. In XPS, photoelectrons generated by irradiating the surface of the pressure-sensitive adhesive layer with X-rays can be detected, and composition information can be obtained from the kinetic energy. Since photoelectrons generated in a deep layer from the surface lose their kinetic energy before reaching the surface, the detection depth in XPS is several nm. Therefore, composition information on the surface layer portion of about several nm from the surface of the pressure-sensitive adhesive layer can be obtained by XPS, and the composition of the vinyl polymer (A) and the acrylic pressure-sensitive adhesive polymer (B) based on the obtained composition information. The ratio can be obtained and Tg can be calculated. The specific measurement conditions for XPS, the Tg calculation method, and the like are as described in the examples described later.

This pressure-sensitive adhesive composition has an adhesive strength of 15 N of a pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition and having a thickness of 50 μm on a 100 μ-thick polyethylene terephthalate film substrate at 85 ° C. / 25 mm or more. Here, the adhesive strength means 180 ° peel strength at a peel speed of 300 mm / min. If the adhesive strength with respect to a PC board in 85 degreeC is 15 N / 25mm or more, there exists a tendency for the durability under high-temperature, high-humidity conditions with respect to a PC board, and the curved-surface adhesiveness with respect to PC to improve. The adhesive strength can be 20 N / 25 mm or more.

This adhesive composition has an adhesive strength of 5 to 85 ° C. for a pressure-sensitive adhesive sheet provided with a 100 μm-thick polyethylene terephthalate film base material with a 50 μm-thick adhesive layer made of the pressure-sensitive adhesive composition. 0.0N / 25 mm or more. Here, the adhesive strength means 180 ° peel strength at a peel speed of 300 mm / min. If the adhesive strength with respect to the PP plate at 85 ° C. is 5.0 N / 25 mm or more, the durability under high-temperature and high-humidity conditions with respect to the PP plate and the curved surface adhesiveness with respect to PP tend to be improved. The adhesive strength can be 7.0 N / 25 mm or more.

In preparing the pressure-sensitive adhesive sheet, the pressure-sensitive adhesive composition is directly applied to a polyethylene terephthalate film substrate and dried to obtain a pressure-sensitive adhesive sheet, or once coated on a release paper or the like, and then a polyethylene terephthalate film Any method of transferring to a substrate may be adopted.
Although drying may be performed at normal temperature, from the viewpoint of productivity and the like, usually, drying is 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.

Adhesion strength is measured according to JIS Z 0237 “Testing method for adhesive tape / adhesive sheet”, and the adhesive strength to a polycarbonate plate or polypropylene plate is measured according to the conditions described in the Examples section described below. taking measurement.

The vinyl polymer (A) of the present invention has moderate 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 ) Tend to be higher than other parts. 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, and exhibits excellent durability. Moreover, it has sufficient softness | flexibility as the whole adhesive layer, and can show favorable adhesive performance. Furthermore, good adhesion to olefinic adherends is exhibited.

The present pressure-sensitive adhesive composition is not particularly limited in its mixing method as long as it contains a predetermined amount of the vinyl polymer (A) and the acrylic pressure-sensitive adhesive polymer (B). 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.

In addition to the vinyl polymer (A) and the acrylic pressure-sensitive adhesive polymer (B), the pressure-sensitive adhesive composition of the present invention includes a crosslinking agent (curing agent), a tackifier, a plasticizer, and an antioxidant as necessary. , UV absorbers, anti-aging agents, flame retardants, fungicides, silane coupling agents, fillers, colorants, and other additives.

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. Among these, an aziridine compound, a glycidyl compound, and an isocyanate compound can also be used.

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

Aromatic isocyanates include diphenylmethane diisocyanate (MDI), crude diphenylmethane diisocyanate, tolylene diisocyanate, naphthalene diisocyanate (NDI), p-phenylene diisocyanate (PPDI), xylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), and 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 0.01 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the (meth) acrylic polymer. You can also Moreover, it can also be 0.03 mass part or more and 5 mass parts or less, 0.05 mass part or more and 2 mass parts or less.

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 di-n-butyl phthalate, di-n-octyl phthalate, bis (2-ethylhexyl) phthalate, di-n-decyl phthalate, diisodecyl phthalate, and the like; 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; and phosphorous acid esters such as triphenyl phosphite Ters; ester oligomers 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, 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- Tetraoxaspiro [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′-thio Sulfur antioxidants such as propionate, dimyristyl 3,3′-thiodipropionate, stearyl 3,3′-thiodipropionate; triphenyl phosphite, diphenylisodecyl phosphite, 4,4′-butylidene-bis (3-methyl-6-tert-butylphenylditridecyl) phosphite, cyclic neopentanetetraylbis (octadecylphosphite), 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, 0-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene, tris (2,4-di-tert-butylphenyl) ) Phosphite, cyclic neopentanetetraylbis (2,4-di-tert-butylphenyl) phosphite, cyclic neopentanetetraylbis (2,6-di-tert-butyl-4-methylphenyl) phos And phosphorus antioxidants such as phyto and 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-methylenebi [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2- (2′-hydroxy-5′-methacryloxyphenyl) -2H— Benzotriazole ultraviolet absorbers such as benzotriazole, 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol]; 2 -Cyanoacrylate UV absorbers such as ethylhexyl-2-cyano-3,3'-diphenyl acrylate, ethyl-2-cyano-3,3'-diphenyl acrylate; nickel bis (octylphenyl) sulfide, [2,2 ' -Thiobis (4-tert-octylphenolate)]-n-butylamine nickel, nickel complex-3,5- And nickel-based UV stabilizers such as di-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, 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) 6-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-mercaptomethylbenz Examples include imidazole, nickel dibutyldithiocarbamate, tris (nonylphenyl) phosphite, dilauryl thiodipropionate, distearyl thiodipropionate.

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, nitrogenous phosphorus compound; red phosphorus, tin oxide, triacid Inorganic flame retardants such as antimony, 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 fungicides include benzimidazole, benzothiazole, trihaloallyl, triazole, organic nitrogen sulfur compounds and the like.

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 vinyl polymer are dispersed in an aqueous medium. It may be used as
In the case of the above-mentioned solution-type pressure-sensitive adhesive composition and 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 salt, 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), dibutyltin maleate, di-n-butyltin maleate ester・ Carboxylates and di-n-butyltin malate esters ・ 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 is a monofunctional and / or polyfunctional (meth) acrylic acid monomer in addition to the vinyl polymer (A) and the acrylic pressure-sensitive polymer (B). In addition, a composition containing a photopolymerization initiator and the like may be used as a so-called syrup-type photocurable pressure-sensitive adhesive composition that is cured by active energy rays such as ultraviolet rays.

In the case of a photocurable pressure-sensitive adhesive composition, the composition may contain an organic solvent or the like, but is generally used as a solventless type that does not contain solvents.

Examples of the monofunctional (meth) acrylic acid monomer 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 (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.
The usage-amount of a photoinitiator and a photosensitizer shall be 0.01 mass part or more and 10 mass parts or less with respect to 100 mass parts of monofunctional and / or polyfunctional (meth) acrylic acid type monomers. You can also.

Furthermore, in addition to the photocurable pressure-sensitive adhesive composition described above, the vinyl polymer (A), a monofunctional and / or polyfunctional (meth) acrylic acid monomer, and a photopolymerization initiator are included. The composition can also be used as a photocurable adhesive composition. 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 includes various general pressure-sensitive adhesive products such as pressure-sensitive adhesive films, pressure-sensitive adhesive sheets, pressure-sensitive adhesive tapes, pressure-sensitive adhesive tapes, surface protective films, surface protective tapes, masking tapes, electrical insulating tapes, laminates, and the like. In addition, it can be suitably used for bonding when a laminate such as various optical films is constructed.

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, and may be in the range of 5 to 250 μm and in the range of 10 to 200 μm. it can.

Further, by using a glass plate and / or a transparent plastic plate as a base material, an adhesive processed product obtained by bonding a glass plate and / or a transparent plastic plate to one or both sides of the pressure-sensitive adhesive layer can be obtained. Such an adhesive processed product can be applied as a laminate of various optical films and the like. Also in this case, the pressure-sensitive adhesive composition may be applied directly on the substrate, or may be transferred to the substrate after being applied to a release paper and dried.

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)>
The Tg of the vinyl polymer (A), the acrylic adhesive polymer (B), and the entire pressure-sensitive adhesive layer was measured by DSC under the following conditions.
DSC: 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) 30m long, 0.32mm inside diameter
Calculation method: Internal standard method

1. Synthesis Example 1 of Vinyl Polymer (Synthesis of Polymer A-1)
In a four-necked flask with an internal volume of 1 liter, butyl acetate (198 parts by mass) and dimethyl 2,2′-azobis (2-methylpropionate) (trade name “V-601” manufactured by Wako Pure Chemical Industries, Ltd.) ( 4.4 parts by mass), the mixture was sufficiently degassed by bubbling nitrogen gas, and the internal temperature of the mixture was raised to 90 ° C. Separately, methyl methacrylate (hereinafter referred to as “MMA”) (141 parts by mass), isobornyl methacrylate (hereinafter referred to as “IBXMA”) (110 parts by mass), V-601 (84 parts by mass), butyl acetate (90 parts by mass) Part) was added dropwise to the flask from the dropping funnel over 5 hours to carry out the polymerization. After completion of the dropping, the polymerization solution is dropped into a mixed solution composed of methanol (4800 parts by mass) and distilled water (1200 parts by mass) to isolate the vinyl polymer in the polymerization solution, thereby obtaining a polymer A-1. It was. 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. Tg was 77 ° C.
The composition of polymer A-1 and the analysis results are shown in Table 1.

Synthesis Example 2 (Synthesis of Polymer A-2)
Synthesis Example 2 (Polymer A-2)
A mixed solution of butyl acetate (198 parts by mass) and V-601 (3.6 parts by mass) is charged into a 1-liter four-necked flask and this mixture is sufficiently degassed by bubbling nitrogen gas. The internal temperature of the mixed solution was raised to 90 ° C. Separately, a mixture of MMA (200 parts by mass), IBXMA (56 parts by mass), V-601 (69 parts by mass), and butyl acetate (90 parts by mass) is dropped into the flask from the dropping funnel over 5 hours. Polymerization was carried out. After completion of the dropping, the polymerization solution was dropped into hexane (6000 parts by mass) to isolate the vinyl polymer in the polymerization solution, thereby obtaining 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 solution of butyl acetate (198 parts by mass) and V-601 (1.2 parts by mass), and this mixture is sufficiently degassed by bubbling nitrogen gas. The internal temperature of the mixed solution was raised to 90 ° C. Separately, a mixture of MMA (165 parts by mass), IBXMA (44 parts by mass), V-601 (23 parts by mass), and butyl acetate (90 parts by mass) is dropped into the flask from the dropping funnel over 5 hours. Polymerization was carried out. After completion of the dropping, the polymerization solution was dropped into hexane (6000 parts by mass) to isolate the vinyl polymer in the polymerization solution 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)
To a four-necked flask with an internal volume of 1 liter, MMA (35 parts by mass), styrene (hereinafter referred to as “St”) (5 parts by mass), butyl acetate (198 parts by mass) and V-601 (7.5 parts by mass) The mixture was sufficiently degassed by bubbling nitrogen gas, and the internal temperature of the mixture was raised to 90 ° C. Separately, a mixed liquid composed of MMA (158 parts by mass), St (47 parts by mass), V-601 (68 parts by mass), and butyl acetate (90 parts by mass) is dropped into the flask from the dropping funnel over 5 hours. Polymerization was performed. After completion of the dropping, the polymerization solution is dropped into a mixed solution consisting of methanol (4800 parts by mass) and distilled water (1200 parts by mass) to isolate the vinyl polymer in the polymerization solution, thereby obtaining a polymer A-4. It was.
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 solution consisting of MMA (19 parts by mass), St (11 parts by mass), butyl acetate (224 parts by mass), V-601 (8.7 parts by mass), The mixture was sufficiently degassed by bubbling with nitrogen gas, and the internal temperature of the mixture was raised to 90 ° C. Separately, a mixture of MMA (108 parts by mass), St (93 parts by mass), V-601 (78 parts by mass), and butyl acetate (90 parts by mass) 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 is dropped into a mixed solution consisting of methanol (4200 parts by mass) and distilled water (1800 parts by mass) to isolate the vinyl polymer in the polymerization solution, thereby obtaining polymer A-5. It was.
Table 1 shows the composition and analysis results of the polymer A-5.

Synthesis Example 6 (Synthesis of Polymer A-6)
A four-necked flask with an internal volume of 1 liter was charged with a mixed liquid consisting of MMA (40 parts by mass), St (6 parts by mass), butyl acetate (250 parts by mass), V-601 (2.5 parts by mass), The mixture was sufficiently degassed by bubbling with nitrogen gas, and the internal temperature of the mixture was raised to 90 ° C. Separately, a mixture of MMA (161 parts by mass), St (43 parts by mass), V-601 (22 parts by mass), and butyl acetate (90 parts by mass) 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 is dropped into a mixed solution consisting of methanol (4200 parts by mass) and distilled water (1800 parts by mass) to isolate the vinyl polymer in the polymerization solution to obtain a polymer A-6. It was.
Table 1 shows the composition and analysis results of Polymer A-6.

Synthesis Example 7 (Synthesis of Polymer A-7)
A four-necked flask with an internal volume of 1 liter was charged with a mixed liquid consisting of MMA (63 parts by mass), butyl acetate (250 parts by mass), and V-601 (4.2 parts by mass). The liquid was sufficiently deaerated by bubbling, and the internal temperature of the mixed solution was raised to 90 ° C. Separately, polymerization was carried out by dropping a mixture of MMA (188 parts by mass), V-601 (46 parts by mass), and butyl acetate (90 parts by mass) from a dropping funnel into the flask over 5 hours. After completion of the dropping, the polymerization solution was dropped into hexane (6000 parts by mass) to isolate the vinyl polymer in the polymerization solution, thereby obtaining a polymer A-7.
The composition and analysis results of the polymer A-7 are shown in Table 1.

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 butyl acetate (250 parts by mass) and V-601 (0.1 parts by mass), and this mixture was sufficiently degassed by bubbling nitrogen gas. The internal temperature of the mixed solution was raised to 90 ° C. Separately, a mixed liquid composed of MMA (200 parts by mass), St (56 parts by mass), V-601 (2.2 parts by mass), and butyl acetate (90 parts by mass) is dropped into the flask from the dropping funnel over 5 hours. Then, polymerization was performed. After completion of the dropwise addition, the polymerization solution is dropped into a mixed solution composed of methanol (4200 parts by mass) and distilled water (1800 parts by mass) to isolate the vinyl polymer in the polymerization solution, thereby obtaining a polymer A-8. It was.
The composition and analysis results of the polymer A-8 are shown in Table 1.

Details of the compounds used in Table 1 are shown below.
MMA: Methyl methacrylate St: Styrene IBXMA: Isobornyl methacrylate

2. Synthesis Synthesis Example 9 of Acrylic Adhesive Polymer (Synthesis of Polymer B-1)
In a four-necked flask with an internal volume of 2 liters, methoxyethyl acrylate (hereinafter referred to as “MEA”) (285 parts by mass), 2-hydroxyethyl acrylate (hereinafter referred to as “HEA”) (15 parts by mass), acetic acid Ethyl (520 parts by mass) was charged, the mixture was sufficiently degassed by bubbling nitrogen gas, the internal temperature of the mixture was raised to 40 ° C., and azobisvaleronitrile (hereinafter referred to as “V-65”) (11.5 parts by mass) was charged and polymerization was started. After 4 hours, the polymerization solution was added dropwise to hexane (10000 parts by mass) to isolate the acrylic adhesive polymer to obtain a polymer B-1. The obtained polymer B-1 was composed of 95% by mass of MEA and 5% by mass of HEA, and had Mw of 500,000, Mn of 70,000, and Mw / Mn of 7.1.

Synthesis Example 10 (Synthesis of Polymer B-2)
MEA (285 parts by mass), acrylic acid (hereinafter referred to as “AA”) (15 parts by mass), and ethyl acetate (520 parts by mass) are charged into a 4-liter flask having an internal volume of 2 liters. Was sufficiently deaerated, the internal temperature of the mixed solution was raised to 40 ° C., V-65 (11.5 parts by mass) was charged, and polymerization was started. After 4 hours, the polymerization solution was dropped into hexane (10000 parts by mass) to isolate the acrylic pressure-sensitive adhesive polymer to obtain a polymer B-2. The obtained polymer B-2 was composed of 95% by mass of MEA and 5% by mass of AA and had Mw of 490,000, Mn of 70,000, and Mw / Mn of 6.8.

Synthesis Example 11 (Synthesis of Polymer B-3)
MEA (239 parts by mass), butyl acrylate (hereinafter referred to as “BA”) (19 parts by mass), HEA (15 parts by mass), and ethyl acetate (520 parts by mass) were added to a 4-neck flask having an internal volume of 2 liters. The mixture was sufficiently degassed by bubbling nitrogen gas, the internal temperature of the mixture was raised to 40 ° C., V-65 (11.4 parts by mass) was charged, and polymerization was started. After 4 hours, the polymerization solution was dropped into hexane (10000 parts by mass) to isolate the acrylic pressure-sensitive adhesive polymer to obtain a polymer B-3. The obtained polymer B-3 was composed of 88% by mass of MEA, 7% by mass of BA, and 5% by mass of HEA, and had Mw of 510,000, Mn of 80,000, and Mw / Mn of 6.4.

Synthesis Example 12 (Synthesis of polymer B-4)
MEA (217 parts by mass), BA (41 parts by mass), HEA (15 parts by mass), and ethyl acetate (520 parts by mass) are charged into a 4-liter flask having an internal volume of 2 liters, and this mixture is bubbled with nitrogen gas. The mixture was sufficiently deaerated, the internal temperature of the mixture was raised to 40 ° C., V-65 (11.4 parts by mass) was charged, and polymerization was started. After 4 hours, the polymerization solution was dropped into hexane (10000 parts by mass) to isolate the acrylic pressure-sensitive adhesive polymer to obtain a polymer B-4. The obtained polymer B-4 was composed of 80% by mass of MEA, 15% by mass of BA, and 5% by mass of HEA, and had Mw of 500,000, Mn of 70,000, and Mw / Mn of 7.2.

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. Similarly, the polymer (B-1) obtained in Synthesis Example 9 was dissolved in ethyl acetate to prepare a polymer (B-1) solution having a solid content concentration of 30% by mass. The polymer (A-1) solution (2 parts by mass), the polymer B-1 solution (100 parts by mass), and Coronate L45 (manufactured by Nippon Polyurethane Industry Co., Ltd.) (0.27 parts by mass) as a cross-linking agent were mixed together, and an adhesive A composition was obtained.

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. The adhesive film sample with a double-sided separator was obtained by standing for aging and aging (aging).

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. From the initial weight and the residual weight, the gel fraction based on the acrylic adhesive polymer (B) was calculated by the following formula (1).

Gel fraction (%) = (weight of residue) / [(initial weight) × (solid content of acrylic adhesive polymer (B)) / (solid content of the entire pressure-sensitive adhesive composition)] × 100 (1 )

<Peel strength for polycarbonate (PC) and polypropylene (PP)>
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. PC board (Mitsubishi Gas Chemical Co., Ltd., Iupilon NF-2000, 2 mm thickness) or PP board (Sumitomo Chemical Co., Ltd., Sumitomo Noblen MH8, 2 mm thickness) is attached to the adherend, and the above-mentioned adhesive sheet for evaluation is bonded to the table. After pressure bonding with a pressure defoaming device TBR-200 (manufactured by Chiyoda Electric Co., Ltd.) for 20 minutes under the conditions of 0.5 MPa and 50 ° C., a tensile tester with constant temperature bath, Strograph R type (manufactured by Toyo Seiki Co., Ltd.) The 180 degree peel strength of the pressure-sensitive adhesive sheet was measured according to JIS Z-0237 “Testing method for pressure-sensitive adhesive tape / pressure-sensitive adhesive sheet” under the conditions of 23 ° C., 60 ° C. and 85 ° C. to obtain the adhesive strength. The peeling speed was 300 mm / min. It was.

<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 polymethylmethacrylate plate to form an adherend, and an adhesive sheet for the above evaluation is attached, and a desktop pressure deaerator TBR-200 (Chiyoda Electric) (Compared with Kogyo Kogyo Co., Ltd.) for 20 minutes under the conditions of 0.5 MPa and 50 ° C., and then using a tensile tester Strograph R type with a thermostatic bath (manufactured by Toyo Seiki Co., Ltd.) Under the condition of ° C., the 180 degree peel strength of the pressure sensitive adhesive sheet was measured according to JIS Z-0237 “Testing method of pressure sensitive adhesive tape and pressure sensitive adhesive sheet” to obtain the adhesive strength. The peeling speed was 300 mm / min. It was.

<Tg of the surface layer portion of the pressure-sensitive adhesive layer>
From the peak area ratio of O1s and C1s measured by X-ray photoelectron spectroscopy (XPS) of the adhesive film sample, vinyl relative to the total amount of vinyl polymer (A) and acrylic adhesive polymer (B) in the surface layer portion of the adhesive layer Each mass fraction (w _A and w _B ) of the polymer (A) and the acrylic adhesive polymer ( _B ) was calculated, and the Tg of the surface layer portion was calculated based on the FOX equation.
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)

A specific method for calculating the mass fraction is described below.
The ratio of the number of oxygen atoms and the number of carbon atoms calculated from the peak area ratio of O1s and C1s by XPS measurement is composed of a vinyl polymer (A) and an acrylic adhesive polymer (B) as shown in the following formula (2). It is represented by the ratio of the number of oxygen atoms and the number of carbon atoms present per unit weight of the surface layer part of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition.

here,
(O / C) _{A + B} : Ratio W between the number of oxygen atoms and the number of carbon atoms calculated from the peak area ratio of O1s and C1s determined from the XPS measurement of the pressure-sensitive adhesive layer obtained by drying the pressure-sensitive adhesive composition _A : Mass fraction of vinyl polymer (A) with respect to the total amount of vinyl polymer (A) and acrylic adhesive polymer (B) M _wA : Weighted average molecular weight of all constituent monomer units of vinyl polymer (A) M _wB : Weighted average molecular weight of all constituent monomer units of the acrylic pressure-sensitive adhesive composition (B) N _OA : Included in the average monomer structural formula of all constituent monomers constituting the vinyl polymer (A) Number of oxygen atoms N _OB : Number of oxygen atoms contained in the average monomer structural formula of all constituent monomers constituting the acrylic adhesive polymer (B) N _CA : Total number constituting the vinyl polymer (A) constituent monomer of the average monomer structure carbon atoms contained in the formula N _CB: acrylic based pressure-sensitive Number of carbon atoms contained averaged in the monomer structure of the total constituent monomer constituting the sex polymer (B)

The number of carbon atoms and oxygen atoms calculated from the peak area ratio of O1s and C1s determined by XPS measurement of the film obtained by drying the vinyl polymer (A) and the acrylic adhesive polymer (B) alone The ratio of the numbers is expressed by the following expressions (3) and (4), respectively.

here,
(O / C) _A : Ratio of the number of oxygen atoms and the number of carbon atoms calculated from the peak area ratio of O1s and C1s determined from the XPS measurement of the film obtained by drying the vinyl polymer (A)

here,
(O / C) _B : Ratio of the number of oxygen atoms and the number of carbon atoms calculated from the peak area ratio of O1s and C1s obtained from XPS measurement of the film obtained by drying the acrylic adhesive polymer (B)

The following formula (5) is derived from the above formulas (2) to (4). From this, the mass fraction of the vinyl polymer (A) with respect to the total amount of the vinyl polymer (A) and the acrylic adhesive polymer (B). (W _A ) is calculated.

Furthermore, the mass fraction (W _B ) of the acrylic adhesive polymer ( _B ) is calculated from the value of W _A obtained above and the following formula (6).

here,
W _B : Mass fraction of the acrylic adhesive polymer (B) with respect to the total amount of the vinyl polymer (A) and the acrylic adhesive polymer (B)

About Example 1, each element in the said Formula (5) is shown below.
(O / C) _{A + B} : 0.260 (actual value)
(O / C) _A : 0.252 (actual value)
(O / C) _B : 0.439 (actual value)
N _CA : From the number of carbon atoms in one molecule of MMA (5), the number of carbon atoms in one molecule of IBXMA (14), and the composition ratio, 5 × 76.1 (mol%) + 14 × 23.9 (mol%) = 7. 15
N _CB : 6 × 94.4 (mol%) + 5 × 5.6 (mol%) = 5 from the number of carbon atoms in the MEA molecule (6), the number of carbon atoms in the HEA molecule (5), and the composition ratio. 94
M _wA : From the molecular weight of MMA (100), the molecular weight of IBXMA (222) and the composition ratio, 100 × 76.1 (mol%) + 222 × 23.9 (mol%) = 129.2
M _wB : From the molecular weight of MEA (130), the molecular weight of HEA (116) and the composition ratio, 130 × 94.4 (mol%) + 116 × 5.6 (mol%) = 129.2
By substituting these values into equation (5), W _A = 0.95 was obtained, and from equation (6), W _B = 0.05 was obtained.

Next, Tg of the surface layer portion was calculated from the surface composition obtained by the measurement according to the formula of FOX represented by the following formula (7), and a value of 69.4 ° C. was obtained.
1 / [Tg of surface layer portion] (K) = W _A / Tg _A + W _B / Tg _B (7)
here,
Tg _A : Tg of vinyl polymer (A) (77 ° C.)
Tg _B : Tg of acrylic adhesive polymer (B) (−31 ° C.)

<Durability>
A laminated film in which an easy-adhesive PET film having a thickness of 100 μm was pasted on one side of an adhesive film sample and a polycarbonate plate was pasted on the other side was prepared. The laminated body was subjected to 50 ° C., 0.5 MPa, 20 minutes. A crimping process was performed. Thereafter, the laminate was subjected to a load for 24 hours in a thermostatic chamber of 60 ° C./95% RH or 85 ° C./85%, 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)>
One release film was peeled off from the adhesive film sample, transferred to a glass plate with a thickness of 1 mm, and the other release film was peeled off. This was allowed to stand at 23 ° C. and 50% RH for 1 day, and then the haze value was measured using a Nippon Denshoku haze meter “Haze Meter NDH2000” (model name). Compatibility was evaluated.

<Curved surface adhesion>
A pressure-sensitive adhesive film was attached to one side of the pressure-sensitive adhesive film sample to prepare a pressure-sensitive adhesive sheet, and then cut to a width of 20 mm and a length of 12.5 mm. This was wound around a cylindrical rod of PP and PC having a diameter of 8 mm and fixed to the cylindrical rod by laminating using a cellophane tape. By the above procedure, the pressure-sensitive adhesive sheet is affixed over approximately 50% of the circumference of each cylindrical bar. Next, with the cellophane tape fixed, a pressure bonding process was performed in an autoclave at 50 ° C., 0.5 MPa, for 20 minutes. After crimping, the sample was stored at 23 ° C. and 50% RH for 1 hour, and the cellophane tape was peeled off. The sample was allowed to stand at 23 ° C. for 24 hours and 85 ° C. for 24 hours, the presence or absence of peeling of the adhesive sheet, and when the adhesive sheet was peeled off, the peeled distance was measured and evaluated based on the following criteria did.
◯: No peeling △: Distance from which the adhesive sheet peeled is 1 mm or less ×: Distance from which the adhesive sheet was peeled exceeded 1 mm

Examples 2 to 9 and Comparative Examples 1 to 8
In Example 1, the types and ratios of the acrylic pressure-sensitive adhesive polymer and the vinyl polymer were changed as shown in Tables 2 and 3 to obtain a pressure-sensitive adhesive composition, and the same measurement as in Example 1 was performed. The results are shown in Tables 2 and 3.

Examples 1 to 9 using the pressure-sensitive adhesive composition of the present invention showed good transparency and high adhesive strength to each adherend over a wide temperature range of 23 ° C to 85 ° C. In addition, laminates having PC as a substrate obtained by using these pressure-sensitive adhesive compositions do not show the lifting or peeling of the pressure-sensitive adhesive sheet even after being exposed to high-temperature and high-humidity conditions for 24 hours. It was excellent. Furthermore, good results were obtained with respect to curved surface adhesion to various adherends.
In particular, Examples 1 to 5 and 7 to 9 having an adhesion strength to PC at 85 ° C. of 15 N / 25 mm or more show good results in all evaluations of durability and curved surface adhesion with PC as an adherend. It was. Examples 1 to 3, 5, 7 and 8 having an adhesive strength to PP at 85 ° C. of 5.0 N / 25 mm or more gave good results in all evaluations of curved surface adhesion using PP as an adherend. Indicated.

Comparative Examples 1 to 5 are experimental examples in which the number of structural units derived from (meth) acrylic acid alkoxyesters relative to all the structural units of the acrylic adhesive polymer (B) is small (80% by mass). No balanced results were obtained.
In Comparative Examples 6 to 8, the acrylic adhesive polymer (B) defined in the present invention was used, but the segregation of the vinyl polymer (A) was insufficient when forming the adhesive layer, and the surface layer There is almost no difference between the Tg of the part and the Tg of the whole pressure-sensitive adhesive. For this reason, it was inferior in the adhesiveness to various to-be-adhered bodies, and durability and curved surface adhesiveness were also inadequate.

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 is excellent in transparency and moist heat 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 organic EL display devices and plasma display panels and various optical films used in these displays.

Claims (9)

1. A pressure-sensitive adhesive composition comprising a vinyl polymer (A) having a glass transition temperature (Tg) of 40 ° C. or higher and 200 ° C. or lower and a number average molecular weight of 500 to 10,000, and an acrylic pressure-sensitive adhesive polymer (B). And
   The acrylic adhesive polymer (B) contains 85% by mass or more of a structural unit derived from an alkoxyalkyl ester of (meth) acrylic acid with respect to the entire structural unit,
   The ratio of the vinyl polymer (A) to 100 parts by mass of the acrylic adhesive polymer (B) is 0.5 to 30 parts by mass,
   When the pressure-sensitive adhesive composition is applied to a separator and dried to obtain a pressure-sensitive adhesive layer, Tg calculated from the composition of the surface layer portion obtained by X-ray photoelectron spectroscopy of the pressure-sensitive adhesive layer is the pressure-sensitive adhesive. A pressure-sensitive adhesive composition characterized by being 30 ° C. or more higher than the Tg of the entire layer.
2. The pressure-sensitive adhesive composition according to claim 1, wherein the vinyl polymer (A) has a structural unit derived from at least one monomer selected from the group consisting of an aliphatic cyclic vinyl compound and an aromatic vinyl compound. .
3. The adhesive strength with respect to the polycarbonate plate at 85 ° C. of the pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer having a thickness of 50 μm made of the pressure-sensitive adhesive composition on a 100 μm-thick polyethylene terephthalate film substrate is 15 N / 25 mm or more. The pressure-sensitive adhesive composition described.
4. The adhesive strength with respect to a polypropylene plate at 85 ° C of a pressure-sensitive adhesive sheet provided with a 100 µm-thick polyethylene terephthalate film base material with a 50 µm-thick pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition is 5.0 N / 25 mm or more. 2. The pressure-sensitive adhesive composition according to 2.
5. A method for producing an adhesive composition, comprising:
   The glass transition temperature (Tg) is 40 ° C. or higher and 200 ° C. or lower and the number average molecular weight with respect to 100 parts by mass of the acrylic adhesive polymer (B) containing 85% by mass or more of the structural unit derived from (meth) acrylic acid alkoxyester. When blending 0.5 parts by weight or more and 30 parts by weight or less of the vinyl polymer (A) having a molecular weight of 500 to 10,000,
   Tg calculated from the composition of the surface layer portion obtained by X-ray photoelectron spectroscopy analysis of the pressure-sensitive adhesive layer obtained by applying the pressure-sensitive adhesive composition to the separator and drying is 30 ° C. than the Tg of the whole pressure-sensitive adhesive layer. The method for producing a pressure-sensitive adhesive composition, wherein the vinyl polymer (A) and the acrylic pressure-sensitive adhesive polymer (B) are selected and blended so as to be higher.
6. A pressure-sensitive adhesive sheet or pressure-sensitive adhesive tape comprising a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to any one of claims 1 to 4 on one side or both sides of a substrate.
7. An adhesive product comprising a glass plate and / or a transparent plastic plate bonded to one or both sides of an adhesive layer formed from the adhesive composition according to any one of claims 1 to 4.
8. An adhesive product comprising an adhesive layer,
   The pressure-sensitive adhesive layer contains a vinyl polymer (A) having a glass transition temperature (Tg) of 40 ° C. or higher and 200 ° C. or lower and a number average molecular weight of 500 to 10,000 and an acrylic pressure-sensitive adhesive polymer (B),
   The acrylic adhesive polymer (B) contains 85% by mass or more of a structural unit derived from an alkoxyalkyl ester of (meth) acrylic acid with respect to the entire structural unit,
   The ratio of the vinyl polymer (A) to 100 parts by mass of the acrylic adhesive polymer (B) is 0.5 parts by mass or more and 30 parts by mass or less.
   The pressure-sensitive adhesive product containing the vinyl polymer (A) at a higher concentration on at least one surface layer side facing in the thickness direction in the pressure-sensitive adhesive layer.
9. The pressure-sensitive adhesive product according to claim 8, wherein Tg calculated from the composition of the surface layer portion obtained by X-ray photoelectron spectroscopy of the pressure-sensitive adhesive layer is 30 ° C or higher than Tg of the whole pressure-sensitive adhesive layer.