JP7106848B2 - Adhesive resin composition and adhesive sheet - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin composition for adhesive and an adhesive sheet.

A touch panel generally has a structure in which a display device such as a liquid crystal display, a transparent substrate on which a transparent electrode is formed, a transparent protective plate, and the like are laminated together. Between these members, there is a gap formed by an air layer, and due to the difference in refractive index between the material forming each member and the air, irregular reflection of light occurs and visibility is impaired. Therefore, in order to eliminate the air layer, each member is bonded together via a transparent adhesive layer. For forming the transparent adhesive layer, a transparent double-sided adhesive sheet called OCA (Optical Clear Adhesive) or a liquid transparent adhesive called liquid OCA (LOCA) is used.

As a pressure-sensitive adhesive resin composition used for OCA, etc., a composition containing, for example, the following (meth)acrylic copolymer has been proposed.
A (meth)acrylic copolymer having a mass average molecular weight of 50,000 to 1,000,000 obtained by polymerizing a monomer mixture containing a macromonomer having a number average molecular weight of 500 or more and less than 6,000 and a vinyl monomer ( Patent document 1).

WO2015/080244

However, the (meth)acrylic copolymer described in Patent Document 1 has a property that it is difficult to whiten when exposed to a high-temperature and high-humidity atmosphere (moisture heat whitening resistance), and the transparent electrode etc. in contact with the adhesive layer are corroded. It is difficult to obtain an adhesive layer that is excellent in both properties (low corrosiveness) that are difficult to remove.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a resin composition for a pressure-sensitive adhesive and a pressure-sensitive adhesive sheet capable of forming a pressure-sensitive adhesive layer with excellent wet heat whitening resistance and low corrosion resistance.

（式中、Ｒ^１は水素原子、メチル基又はＣＨ_２ＯＨを示し、Ｒ^２はＯＲ^３、ハロゲン原子、ＣＯＲ^４、ＣＯＯＲ^５、ＣＮ、ＣＯＮＲ^６Ｒ^７、ＮＨＣＯＲ^８、又はＲ^９を示し、
Ｒ^３～Ｒ^８はそれぞれ独立に、水素原子、非置換の若しくは置換基を有するアルキル基、非置換の若しくは置換基を有する脂環式基、非置換の若しくは置換基を有するアリール基、非置換の若しくは置換基を有するヘテロアリール基、非置換の若しくは置換基を有する非芳香族の複素環式基、非置換の若しくは置換基を有するアラルキル基、非置換の若しくは置換基を有するアルカリール基、非置換の若しくは置換基を有するオルガノシリル基、又は非置換の若しくは置換基を有する（ポリ）オルガノシロキサン基を示し、これらの基における置換基はそれぞれ、アルキル基、アリール基、ヘテロアリール基、非芳香族の複素環式基、アラルキル基、アルカリール基、カルボン酸基、カルボン酸エステル基、エポキシ基、ヒドロキシ基、アルコキシ基、１級アミノ基、２級アミノ基、３級アミノ基、イソシアナト基、スルホン酸基及びハロゲン原子からなる群から選ばれる少なくとも１種であり、Ｒ^９は非置換の若しくは置換基を有するアリール基、又は非置換の若しくは置換基を有するヘテロアリール基、又は非置換の若しくは置換基を有する非芳香族の複素環式基を示し、これらの基における置換基はそれぞれ、アルキル基、アリール基、ヘテロアリール基、非芳香族の複素環式基、アラルキル基、アルカリール基、カルボン酸基、カルボン酸エステル基、エポキシ基、ヒドロキシ基、アルコキシ基、１級アミノ基、２級アミノ基、３級アミノ基、イソシアナト基、スルホン酸基、非置換の若しくは置換基を有するオレフィン基及びハロゲン原子からなる群から選ばれる少なくとも１種である。）
［２］ 前記マクロモノマー（ａ）が下記式（１）で表される［１］に記載の粘着剤用樹脂組成物。

（式中、Ｒは水素原子、非置換の若しくは置換基を有するアルキル基、非置換の若しくは置換基を有する脂環式基、非置換の若しくは置換基を有するアリール基、非置換の若しくは置換基を有するヘテロアリール基、非置換の若しくは置換基を有する非芳香族の複素環式基、非置換の若しくは置換基を有するアラルキル基、非置換の若しくは置換基を有するアルカリール基、非置換の若しくは置換基を有するオルガノシリル基、又は非置換の若しくは置換基を有する（ポリ）オルガノシロキサン基を示し、Ｑは２以上の前記式（ａ’）で表される構成単位を含む主鎖部分を示し、Ｚは末端基を示す。）
［３］ 前記マクロモノマー（ａ）由来の構成単位の含有量が、全構成単位の合計質量に対して３～６０質量％である、［１］又は［２］の何れかに記載の粘着剤用樹脂組成物。
［４］ 前記共重合体（Ａ）の酸価が３．９ｍｇＫＯＨ／ｇ以下である、［１］～［３］の何れかに記載の粘着剤用樹脂組成物。
［５］ マクロモノマー（ａ）とビニル単量体（ｂ）を重合して得られるポリマーのＴｇの差が５０℃以上である、［１］～［４］の何れかに記載の粘着剤用樹脂組成物。
［６］ ビニル単量体（ｂ）が炭素数が４以上のアルキル（メタ）アクリレート（ｙ１）を含む、［１］～［５］の何れかに記載の粘着剤用樹脂組成物。
［７］ 前記(メタ）アクリル系共重合体（Ａ）の重量平均分子量が１０００～１００万である［１］～［６］の何れかに記載の粘着剤用樹脂組成物。
［８］ 前記ビニル単量体（ｂ）由来の構成単位中の前記アミド結合を有する構成単位の含有量が、前記ビニル単量体（ｂ）由来の構成単位の合計質量に対して０．１～３０質量％である、［１］～［７］何れかに記載の（メタ）アクリル系共重合体を含む粘着剤用樹脂組成物。
［９］ 前記マクロモノマー（ａ）の数量平均分子量が５００～１０万である［１］～[８]の何れかに記載の（メタ）アクリル系共重合体（Ａ）を含む粘着剤用樹脂組成物。
［１０］ ［１］～［９］何れかに記載の粘着剤用樹脂組成物を用いた粘着シート。 The present invention has the following aspects.
[1] A (meth)acrylic copolymer having a structural unit derived from a macromonomer (a) having two or more structural units represented by the following formula (a′) and a structural unit derived from a vinyl monomer (b) A pressure-sensitive adhesive resin composition comprising a polymer (A), wherein the (meth)acrylic copolymer (A) has an amide bond.

(wherein R ¹ represents a hydrogen atom, a methyl group or CH ₂ OH, R ² represents OR ³ , a halogen atom, COR ⁴ , COOR ⁵ , CN, CONR ⁶ R ⁷ , NHCOR ⁸ or R ⁹ ,
R ³ to R ⁸ are each independently a hydrogen atom, an unsubstituted or substituted alkyl group, an unsubstituted or substituted alicyclic group, an unsubstituted or substituted aryl group, an unsubstituted or substituted heteroaryl group, unsubstituted or substituted non-aromatic heterocyclic group, unsubstituted or substituted aralkyl group, unsubstituted or substituted alkaryl group, represents an unsubstituted or substituted organosilyl group, or an unsubstituted or substituted (poly)organosiloxane group, the substituents in these groups being alkyl groups, aryl groups, heteroaryl groups, non- Aromatic heterocyclic group, aralkyl group, alkaryl group, carboxylic acid group, carboxylic acid ester group, epoxy group, hydroxy group, alkoxy group, primary amino group, secondary amino group, tertiary amino group, isocyanato group , a sulfonic acid group and a halogen atom, and R ⁹ is an unsubstituted or substituted aryl group, an unsubstituted or substituted heteroaryl group, or an unsubstituted or a non-aromatic heterocyclic group having a substituent, and the substituents in these groups are alkyl groups, aryl groups, heteroaryl groups, non-aromatic heterocyclic groups, aralkyl groups, and alkaryl groups, respectively. , carboxylic acid groups, carboxylic acid ester groups, epoxy groups, hydroxy groups, alkoxy groups, primary amino groups, secondary amino groups, tertiary amino groups, isocyanato groups, sulfonic acid groups, unsubstituted or substituted olefins It is at least one selected from the group consisting of groups and halogen atoms. )
[2] The resin composition for pressure-sensitive adhesives according to [1], wherein the macromonomer (a) is represented by the following formula (1).

(wherein R is a hydrogen atom, an unsubstituted or substituted alkyl group, an unsubstituted or substituted alicyclic group, an unsubstituted or substituted aryl group, an unsubstituted or substituted heteroaryl group, unsubstituted or substituted non-aromatic heterocyclic group, unsubstituted or substituted aralkyl group, unsubstituted or substituted alkaryl group, unsubstituted or represents an organosilyl group having a substituent, or an unsubstituted or substituted (poly)organosiloxane group, and Q represents a main chain portion containing two or more structural units represented by the formula (a′); , Z indicates a terminal group.)
[3] The pressure-sensitive adhesive according to any one of [1] or [2], wherein the content of structural units derived from the macromonomer (a) is 3 to 60% by mass with respect to the total mass of all structural units. resin composition for
[4] The resin composition for adhesives according to any one of [1] to [3], wherein the copolymer (A) has an acid value of 3.9 mgKOH/g or less.
[5] The pressure-sensitive adhesive according to any one of [1] to [4], wherein the polymer obtained by polymerizing the macromonomer (a) and the vinyl monomer (b) has a difference in Tg of 50°C or more. Resin composition.
[6] The resin composition for pressure-sensitive adhesive according to any one of [1] to [5], wherein the vinyl monomer (b) contains an alkyl (meth)acrylate (y1) having 4 or more carbon atoms.
[7] The pressure-sensitive adhesive resin composition according to any one of [1] to [6], wherein the (meth)acrylic copolymer (A) has a weight average molecular weight of 1,000 to 1,000,000.
[8] The content of the structural unit having an amide bond in the structural units derived from the vinyl monomer (b) is 0.1 relative to the total mass of the structural units derived from the vinyl monomer (b). A pressure-sensitive adhesive resin composition comprising the (meth)acrylic copolymer according to any one of [1] to [7], which is up to 30% by mass.
[9] A pressure-sensitive adhesive resin containing the (meth)acrylic copolymer (A) according to any one of [1] to [8], wherein the macromonomer (a) has a number average molecular weight of 500 to 100,000 Composition.
[10] A pressure-sensitive adhesive sheet using the resin composition for pressure-sensitive adhesives according to any one of [1] to [9].

ADVANTAGE OF THE INVENTION According to this invention, the resin composition for adhesives and adhesive sheet which can form the adhesion layer excellent in wet heat whitening resistance and low corrosiveness can be provided.

The following term definitions apply throughout the specification and claims.
"Vinyl monomer" means a monomer having an ethylenically unsaturated bond (polymerizable carbon-carbon double bond).
A "(meth)acrylic copolymer" means a copolymer in which at least a part of structural units are structural units derived from a (meth)acrylic monomer. The (meth)acrylic polymer may further contain structural units derived from monomers other than the (meth)acrylic monomer (for example, styrene).
A "(meth)acrylic monomer" means a monomer having a (meth)acryloyl group.
"(Meth)acryloyl group" is a generic term for acryloyl group and methacryloyl group. "(Meth)acrylate" is a generic term for acrylate and methacrylate. "(Meth)acrylic acid" is a generic term for acrylic acid and methacrylic acid. "(Meth)acrylonitrile" is a generic term for acrylonitrile and methacrylonitrile. "(Meth)acrylamide" is a generic term for acrylamide and methacrylamide.

[(Meth) acrylic copolymer]
The (meth)acrylic copolymer (hereinafter also referred to as "copolymer (A)") contained in the adhesive resin composition of the present invention has two structural units represented by the formula (a') It has structural units derived from the macromonomer (a) and structural units derived from the vinyl monomer (b).
The copolymer (A) is typically a graft copolymer in which a polymer chain derived from the macromonomer (a) and a polymer chain composed of structural units derived from the vinyl monomer (b) are bonded. or has a block copolymer structure.

Some or all of the structural units of the macromonomer (a) and the structural units derived from the vinyl monomer (b) are structural units derived from (meth)acrylic monomers.
The structural unit derived from the (meth)acrylic monomer may be contained in either the structural unit of the macromonomer (a) or the structural unit derived from the vinyl monomer (b), or may be contained in both. may Both are typically included.
The content of the structural unit derived from the (meth)acrylic monomer in the copolymer (A) is 20 to 20 with respect to the total mass (100% by mass) of all structural units constituting the copolymer (A). 100% by mass is preferred, and 40 to 100% by mass is more preferred.

（式中、Ｒ^１は水素原子、メチル基又はＣＨ_２ＯＨを示し、Ｒ^２はＯＲ^３、ハロゲン原子、ＣＯＲ^４、ＣＯＯＲ^５、ＣＮ、ＣＯＮＲ^６Ｒ^７、ＮＨＣＯＲ^８、又はＲ^９を示し、
Ｒ^３～Ｒ^８はそれぞれ独立に、水素原子、非置換の若しくは置換基を有するアルキル基、非置換の若しくは置換基を有する脂環式基、非置換の若しくは置換基を有するアリール基、非置換の若しくは置換基を有するヘテロアリール基、非置換の若しくは置換基を有する非芳香族の複素環式基、非置換の若しくは置換基を有するアラルキル基、非置換の若しくは置換基を有するアルカリール基、非置換の若しくは置換基を有するオルガノシリル基、又は非置換の若しくは置換基を有する（ポリ）オルガノシロキサン基を示し、これらの基における置換基はそれぞれ、アルキル基、アリール基、ヘテロアリール基、非芳香族の複素環式基、アラルキル基、アルカリール基、カルボン酸基、カルボン酸エステル基、エポキシ基、ヒドロキシ基、アルコキシ基、１級アミノ基、２級アミノ基、３級アミノ基、イソシアナト基、スルホン酸基及びハロゲン原子からなる群から選ばれる少なくとも１種であり、Ｒ^９は非置換の若しくは置換基を有するアリール基、又は非置換の若しくは置換基を有するヘテロアリール基、又は非置換の若しくは置換基を有する非芳香族の複素環式基を示し、これらの基における置換基はそれぞれ、アルキル基、アリール基、ヘテロアリール基、非芳香族の複素環式基、アラルキル基、アルカリール基、カルボン酸基、カルボン酸エステル基、エポキシ基、ヒドロキシ基、アルコキシ基、１級アミノ基、２級アミノ基、３級アミノ基、イソシアナト基、スルホン酸基、非置換の若しくは置換基を有するオレフィン基及びハロゲン原子からなる群から選ばれる少なくとも１種である。） The resin composition for a pressure-sensitive adhesive of the present invention comprises a structural unit derived from a macromonomer (a) having two or more structural units represented by the following formula (a′) and a structural unit derived from a vinyl monomer (b). A pressure-sensitive adhesive resin composition containing a (meth)acrylic copolymer (A), wherein the (meth)acrylic copolymer (A) is a pressure-sensitive adhesive resin composition having an amide bond be.

(wherein R ¹ represents a hydrogen atom, a methyl group or CH ₂ OH, R ² represents OR ³ , a halogen atom, COR ⁴ , COOR ⁵ , CN, CONR ⁶ R ⁷ , NHCOR ⁸ or R ⁹ ,
R ³ to R ⁸ are each independently a hydrogen atom, an unsubstituted or substituted alkyl group, an unsubstituted or substituted alicyclic group, an unsubstituted or substituted aryl group, an unsubstituted or substituted heteroaryl group, unsubstituted or substituted non-aromatic heterocyclic group, unsubstituted or substituted aralkyl group, unsubstituted or substituted alkaryl group, represents an unsubstituted or substituted organosilyl group, or an unsubstituted or substituted (poly)organosiloxane group, the substituents in these groups being alkyl groups, aryl groups, heteroaryl groups, non- Aromatic heterocyclic group, aralkyl group, alkaryl group, carboxylic acid group, carboxylic acid ester group, epoxy group, hydroxy group, alkoxy group, primary amino group, secondary amino group, tertiary amino group, isocyanato group , a sulfonic acid group and a halogen atom, and R ⁹ is an unsubstituted or substituted aryl group, an unsubstituted or substituted heteroaryl group, or an unsubstituted or a non-aromatic heterocyclic group having a substituent, and the substituents in these groups are alkyl groups, aryl groups, heteroaryl groups, non-aromatic heterocyclic groups, aralkyl groups, and alkaryl groups, respectively. , carboxylic acid groups, carboxylic acid ester groups, epoxy groups, hydroxy groups, alkoxy groups, primary amino groups, secondary amino groups, tertiary amino groups, isocyanato groups, sulfonic acid groups, unsubstituted or substituted olefins It is at least one selected from the group consisting of groups and halogen atoms. )

In the copolymer (A), at least part of the structural units of the macromonomer (a) and the structural units derived from the vinyl monomer (b) have amide bonds. By including a structural unit having an amide bond in the copolymer (A), it is possible to form an adhesive layer excellent in wet heat whitening resistance and low corrosion resistance.
The structural unit having an amide bond may be contained in either the structural unit of the macromonomer (a) or the structural unit derived from the vinyl monomer (b), or may be contained in both.
A structural unit having an amide bond is typically a structural unit derived from an amide bond-containing monomer (hereinafter also referred to as "monomer (x)").

In the copolymer (A), it is preferred that some of the constituent units of the macromonomer (a) and the constituent units derived from the vinyl monomer (b) have an amide bond. That is, all of the structural units of the macromonomer (a) and the structural units derived from the vinyl monomer (b) do not have an amide bond, and the structural units of the macromonomer (a) and the vinyl monomer (b ) preferably includes a structural unit having an amide bond and a structural unit having no amide bond. By containing a structural unit having no amide bond, performance as an adhesive such as adhesive strength can be exhibited.
The structural unit having no amide bond may be contained in either the structural unit of the macromonomer (a) or the structural unit derived from the vinyl monomer (b), or may be contained in both.
A structural unit having no amide bond is typically a structural unit derived from a monomer other than the monomer (x) (hereinafter also referred to as "monomer (y)").
The monomer (x) and the monomer (y) will be explained later in detail.

<Macromonomer (a)>
The macromonomer (a) is a compound having two or more structural units derived from a monomer having a radically polymerizable group (hereinafter also referred to as "monomer (a1)"), and is a radically polymerizable group or a hydroxyl group. , an isocyanate group, an epoxy group, a carboxyl group, an amino group, an amide group, a thiol group, an acid anhydride group, and a carbodiimide group.
The monomer (a1) will be described later in detail. Two or more constitutional units possessed by the macromonomer (a) may be the same or different.

When the macromonomer (a) has the radically polymerizable group, the copolymer (A) can be obtained by copolymerizing the macromonomer (a) and the vinyl monomer (b) by radical polymerization.
When the macromonomer (a) has the addition-reactive functional group, the vinyl monomer (b) usually contains a vinyl monomer having a functional group capable of reacting with the addition-reactive functional group. The copolymer (A) can be obtained by reacting the functional group of the polymer composed of structural units derived from the vinyl monomer (b) with the macromonomer having the addition-reactive functional group.

Examples of the combination of the addition-reactive functional group and the functional group capable of reacting with this functional group include the following combinations.
A combination of a hydroxyl group and a carboxyl group or an acid anhydride group.
Combinations of isocyanate groups and carboxyl groups or hydroxyl groups or thiol groups.
A combination of an epoxy group and an amino group.
A combination of a carboxyl group and an epoxy group or a carbodiimide group.
A combination of an amino group and a carboxyl group.
A combination of an amide group and a carboxyl group.
A combination of a thiol group and an epoxy group.

When the macromonomer (a) has a radically polymerizable group, the number of radically polymerizable groups in the macromonomer (a) may be one or two or more, but preferably one. When the macromonomer (a) has the addition-reactive functional group, the addition-reactive functional group in the macromonomer (a) may be one or two or more. preferable.
The macromonomer (a) may have either or both of the radically polymerizable group and the functional group. When the macromonomer (a) has both the radically polymerizable group and the functional group, the number of the radically polymerizable group and the functional group may be one or two or more. The macromonomer (a) may have the radical polymerizable group and the functional group inside the repeating unit or may have it at the terminal, but the viscosity of the adhesive resin composition may be adjusted. It is preferable to have it only at the terminal because it is easy to use.

The macromonomer (a) preferably has a radically polymerizable group from the viewpoint of being copolymerizable with the vinyl monomer (b). When the copolymer (A) is a copolymer of the macromonomer (a) and the vinyl monomer (b), the functional group of the polymer comprising structural units derived from the vinyl monomer (b) and the above Compared to the reaction product with a macromonomer having an addition-reactive functional group, it is superior in that the introduction amount of the macromonomer (a) can be easily controlled and corrosion due to residual functional groups can be reduced.

As the radically polymerizable group possessed by the macromonomer (a), a group having an ethylenically unsaturated bond is preferred. Groups having an ethylenically unsaturated bond include, for example, CH ₂ ═C(COOR)—CH ₂ —, (meth)acryloyl group, 2-(hydroxymethyl)acryloyl group, vinyl group and the like.
wherein R is a hydrogen atom, an unsubstituted or substituted alkyl group, an unsubstituted or substituted alicyclic group, an unsubstituted or substituted aryl group, an unsubstituted or substituted heteroaryl group, unsubstituted or substituted non-aromatic heterocyclic group, unsubstituted or substituted aralkyl group, unsubstituted or substituted alkaryl group, unsubstituted or substituted represents an organosilyl group having a group or an unsubstituted or substituted (poly)organosiloxane group.

Examples of unsubstituted alkyl groups for R include branched or linear alkyl groups having 1 to 22 carbon atoms. Specific examples of branched or linear alkyl groups having 1 to 22 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, t-butyl group, i-butyl group and pentyl. group (amyl group), i-pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, i-octyl group, nonyl group, i-nonyl group, decyl group, i-decyl group, undecyl group, dodecyl group (lauryl group), tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group (stearyl group), i-octadecyl group, nonadecyl group, icosyl group and docosyl group.

The unsubstituted alicyclic group for R may be monocyclic or polycyclic, and examples thereof include alicyclic groups having 3 to 20 carbon atoms. The alicyclic group is preferably a saturated alicyclic group, and specific examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a bicyclo[2.2.1]heptyl group, and a cyclooctyl group. groups, and adamantyl groups.

Examples of unsubstituted aryl groups for R include aryl groups having 6 to 18 carbon atoms. Specific examples of aryl groups having 6 to 18 carbon atoms include phenyl and naphthyl groups.
Examples of unsubstituted heteroaryl groups for R include pyridyl groups and carbazolyl groups.
Examples of unsubstituted non-aromatic heterocyclic groups include pyrrolidinyl groups, pyrrolidone groups, lactam groups and the like.
Examples of unsubstituted aralkyl groups include benzyl group and phenylethyl group.

Examples of unsubstituted organosilyl groups include -SiR ¹⁷ R ¹⁸ R ¹⁹ (where R ¹⁷ to R ¹⁹ are each independently an unsubstituted or substituted alkyl group, an unsubstituted or substituted alicyclic or an unsubstituted or substituted aryl group).
Examples of the unsubstituted or substituted alkyl group for R ¹⁷ to R ¹⁹ include the same as those described above, such as methyl group, ethyl group, n-propyl group, n-butyl group, n-amyl group, n -hexyl group, n-octyl group, n-dodecyl group, stearyl group, lauryl group, isopropyl group, isobutyl group, s-butyl group, 2-methylisopropyl group, benzyl group and the like. Examples of the unsubstituted or substituted alicyclic group include the same groups as those described above, such as a cyclohexyl group. Examples of the unsubstituted or substituted aryl group include those mentioned above, such as a phenyl group and p-methylphenyl. R ¹⁷ to R ¹⁹ may be the same or different.

Examples of unsubstituted (poly)organosiloxane groups include -SiR ³⁰ R ³¹ -OR ³² , -(SiR ³³ R ³⁴ -O-) _n -R ³⁵ (wherein R ³⁰ to R ³⁵ are each independently an unsubstituted or substituted alkyl group, an unsubstituted or substituted alicyclic group, or an unsubstituted or substituted aryl group).
Examples of the unsubstituted or substituted alkyl group, alicyclic group, and aryl group for R ³⁰ to R ³⁵ are the same as those described above.

Substituents in R (substituted alkyl group, substituted alicyclic group, substituted aryl group, substituted heteroaryl group, substituted non-aromatic heterocyclic group, substituted Substituents for each of an aralkyl group having a group, an alkaryl group having a substituent, and an organosilyl group having a substituent) include, for example, an alkyl group (excluding the case where R is an alkyl group having a substituent), a group consisting of an aryl group, —COOR ¹¹ , a cyano group, —OR ¹² , —NR ¹³ R ¹⁴ , —CONR ¹⁵ R ¹⁶ , a halogen atom, an allyl group, an epoxy group, a siloxy group, and a group exhibiting hydrophilicity or ionicity; At least one selected from
Here, R ¹¹ to R ¹⁶ are each independently a hydrogen atom, an unsubstituted or substituted alkyl group, an unsubstituted or substituted alicyclic group, or an unsubstituted or substituted aryl indicates a group. Examples of these groups are the same as those described above.

Examples of the alkyl group and aryl group in the above substituent include the same groups as the unsubstituted alkyl group and unsubstituted aryl group, respectively.
R ¹¹ of —COOR ¹¹ in the above substituent is preferably a hydrogen atom or an unsubstituted alkyl group. That is, -COOR ¹¹ is preferably a carboxy group or an alkoxycarbonyl group. An alkoxycarbonyl group includes, for example, a methoxycarbonyl group.
R ¹² of —OR ¹² in the above substituent is preferably a hydrogen atom or an unsubstituted alkyl group. That is, -OR ¹² is preferably a hydroxy group or an alkoxy group. The alkoxy group includes, for example, an alkoxy group having 1 to 12 carbon atoms, and a specific example thereof includes a methoxy group.

Examples of —NR ¹³ R ¹⁴ in the above substituent include an amino group, a monomethylamino group, a dimethylamino group and the like.
Examples of —CONR ¹⁵ R ¹⁶ in the above substituents include carbamoyl group (—CONH ₂ ), N-methylcarbamoyl group (—CONHCH ₃ ), N,N-dimethylcarbamoyl group (dimethylamide group: —CON(CH ₃ ) ₂ ) and the like.

Examples of the halogen atom in the substituent include fluorine atom, chlorine atom, bromine atom and iodine atom.
Examples of hydrophilic or ionic groups in the above substituents include alkali salts of carboxy groups or alkali salts of sulfoxy groups, poly(alkylene oxide) groups such as polyethylene oxide groups and polypropylene oxide groups, and quaternary ammonium bases. of cationic substituents.

R is preferably an unsubstituted or substituted alkyl group, or an unsubstituted or substituted alicyclic group, and an unsubstituted alkyl group or an unsubstituted or substituted alicyclic group. Cyclic groups are more preferred.
Among the above, from the ease of availability, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl group, cyclo Propyl group, cyclobutyl group, isobornyl group and adamantyl group are preferred, and methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, t-butyl group, cyclopropyl group, cyclobutyl group, isobornyl group and Adamantyl groups are more preferred.

As the radically polymerizable group possessed by the monomer (a1), a group having an ethylenically unsaturated bond is preferred, like the radically polymerizable group preferably possessed by the macromonomer (a). That is, monomer (a1) is preferably a vinyl monomer.

Monomer (a1) includes monomer (x) and monomer (y).
Monomer (x) is an amide bond-containing monomer. The monomer (x) is preferably an amide bond-containing vinyl monomer, such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl (meth)acrylamide, ) acrylamide, Nt-butyl (meth)acrylamide, Nt-octyl (meth)acrylamide, N-methylol (meth)acrylamide, hydroxyethyl (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-butoxy methyl (meth)acrylamide, diacetone (meth)acrylamide, N,N-dimethylaminoethyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, N-vinylacetamide, maleic acid amide, N,N' - Amide bond-containing linear vinyl monomers such as methylenebis(meth)acrylamide; ; and the like.
Among these, (meth)acrylamide is preferable from the viewpoint of resistance to whitening under heat and humidity.

Monomer (y) is a monomer other than monomer (x). That is, it is a monomer containing no amide bond. Various monomers (y) can be used, and examples thereof include the following.
Methyl (meth)acrylate, Ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, (meth)acrylic t-butyl acid, isoamyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, ( meth)isononyl acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, hexadecyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, ( phenyl methacrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, 3,5,5-trimethylcyclohexyl (meth)acrylate, Dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, terpene acrylate and its derivatives, hydrogenated rosin acrylate and its derivatives, docosyl (meth)acrylate Hydrocarbon group-containing (meth) acrylic acid ester such as;
2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, hydroxyl group-containing (meth)acrylic acid esters such as glycerol (meth)acrylate;
(Meth)acrylic acid, 2-(meth)acryloyloxyethylhexahydrophthalate, 2-(meth)acryloyloxypropylhexahydrophthalate, 2-(meth)acryloyloxyethyl phthalate, 2-(meth)acryloyloxy Propyl phthalic acid, 2-(meth)acryloyloxyethyl maleate, 2-(meth)acryloyloxypropyl maleate, 2-(meth)acryloyloxyethylsuccinic acid, 2-(meth)acryloyloxypropylsuccinic acid, crotonic acid , fumaric acid, maleic acid, itaconic acid, citraconic acid, monomethyl maleate, monoethyl maleate, monooctyl maleate, monomethyl itaconate, monoethyl itaconate, monobutyl itaconate, monooctyl itaconate, monomethyl fumarate, monoethyl fumarate , carboxyl group-containing vinyl monomers such as monobutyl fumarate, monooctyl fumarate, monoethyl citraconate;
Acid anhydride group-containing vinyl monomers such as maleic anhydride and itaconic anhydride;
unsaturated dicarboxylic acid diester monomers such as dimethylmalate, dibutylmalate, dimethylfumarate, dibutylfumarate, dibutylitaconate, diperfluorocyclohexylfumarate;
epoxy group-containing vinyl monomers such as glycidyl (meth)acrylate, glycidyl α-ethyl acrylate, and 3,4-epoxybutyl (meth)acrylate;
Amino group-containing (meth)acrylic acid esters such as dimethylaminoethyl (meth)acrylate and diethylaminoethyl (meth)acrylate;
Divinylbenzene, ethylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, diethylene glycol di(meth)acrylate meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1, 9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, allyl ( polyfunctional vinyl monomers such as meth)acrylates, triallyl cyanurate, diallyl maleate, polypropylene glycol diallyl ether;
Heterocyclic monomers such as vinylpyridine and vinylcarbazole;
polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, n-butoxyethyl (meth)acrylate, isobutoxyethyl (meth)acrylate , t-butoxyethyl (meth)acrylate, ethoxyethoxyethyl (meth)acrylate, phenoxyethyl (meth)acrylate, nonylphenoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, (meth)acrylate Acetoxyethyl acrylate, "Plaxel FM" (manufactured by Daicel Chemical Industries, Ltd., a caprolactone addition monomer, trade name), "Blenmer PME-100" (manufactured by NOF Corporation, methoxypolyethylene glycol methacrylate (the ethylene glycol chain is 2 product), trade name), “Blenmer PME-200” (NOF Corporation methoxypolyethylene glycol methacrylate (ethylene glycol chain is 4), trade name), “Blenmer PME-400” (NOF ( Methoxy polyethylene glycol methacrylate (ethylene glycol chain is 9, trade name) manufactured by NOF Corporation, "Blemmer 50POEP-800B" (NOF Corporation octoxy polyethylene glycol-polypropylene glycol-methacrylate (ethylene glycol chain) is 8 and the propylene glycol chain is 6), trade name), "Blemmer 20ANEP-600" (NOF Corporation nonylphenoxy (ethylene glycol-polypropylene glycol) monoacrylate, trade name), " Blenmer AME-100” (manufactured by NOF Corporation, trade name), “Blenmer AME-200” (manufactured by NOF Corporation, trade name) and “Blenmer 50AOEP-800B” (manufactured by NOF Corporation, trade name) name) glycol ester-based monomers such as
3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, vinyltrimethoxysilane , silane coupling agent-containing monomers such as vinyltriethoxysilane;
trimethylsilyl (meth)acrylate, triethylsilyl (meth)acrylate, tri-n-propylsilyl (meth)acrylate, tri-n-butylsilyl (meth)acrylate, tri-n-amylsilyl (meth)acrylate, tri-n-hexylsilyl (Meth)acrylate, tri-n-octylsilyl (meth)acrylate, tri-n-dodecylsilyl (meth)acrylate, triphenylsilyl (meth)acrylate, tri-p-methylphenylsilyl (meth)acrylate, tribenzylsilyl (Meth) acrylate, triisopropylsilyl (meth) acrylate, triisobutylsilyl (meth) acrylate, tri-s-butylsilyl (meth) acrylate, tri-2-methylisopropylsilyl (meth) acrylate, tri-t-butylsilyl (meth) ) acrylate, ethyldimethylsilyl (meth)acrylate, n-butyldimethylsilyl (meth)acrylate, diisopropyl-n-butylsilyl (meth)acrylate, n-octyldi-n-butylsilyl (meth)acrylate, diisopropylstearylsilyl (meth)acrylate , dicyclohexylphenylsilyl (meth)acrylate, t-butyldiphenylsilyl (meth)acrylate, lauryldiphenylsilyl (meth)acrylate, triisopropylsilylmethyl maleate, triisopropylsilylamyl maleate, tri-n-butylsilyl-n-butyl maleate , t-butyldiphenylsilylmethylmalate, t-butyldiphenylsilyl-n-butylmalate, triisopropylsilylmethylfumarate, triisopropylsilylamylfumarate, tri-n-butylsilyl-n-butylfumarate, t-butyldiphenyl Silyl methyl fumarate, t-butyldiphenylsilyl-n-butyl fumarate, Silaplane FM-0711 (manufactured by JNC Corporation, trade name), Silaplane FM-0721 (manufactured by JNC Corporation, trade name), Sila Plain FM-0725 (manufactured by JNC Co., Ltd., trade name), Silaplane TM-0701 (manufactured by JNC Co., Ltd., trade name), Silaplane TM-0701T (manufactured by JNC Co., Ltd., trade name), X-22 -174ASX (manufactured by Shin-Etsu Chemical Co., Ltd., trade name), X-22-174BX (manufactured by Shin-Etsu Chemical Co., Ltd., trade name), KF-2012 (manufactured by Shin-Etsu Chemical Co., Ltd., trade name), X -22-2426 (Shin-Etsu Gakukogyo Co., Ltd., trade name), X-22-2404 (Shin-Etsu Chemical Co., Ltd., trade name), and other organosilyl group-containing monomers other than silane coupling agent-containing monomers;
Halogenated olefins such as vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, chlorotrifluoroethylene;
(meth) isocyanato group-containing monomers such as 2-isocyanatoethyl acrylate;
2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3,3-pentafluorophenyl (meth)acrylate, 2-(perfluorobutyl)ethyl (meth)acrylate, 3-(perfluoro Butyl)-2-hydroxypropyl (meth)acrylate, 2-(perfluorohexyl)ethyl (meth)acrylate, 3-perfluorohexyl-2-hydroxypropyl (meth)acrylate, 3-(perfluoro-3-methylbutyl) -2-hydroxypropyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 1H,1H,5H-octafluoropentyl (meth)acrylate, 1H,1H,5H-octafluoropentyl ( meth)methacrylate, 1H,1H,2H,2H-tridecafluorooctyl (meth)acrylate, 1H-1-(trifluoromethyl)trifluoroethyl (meth)acrylate, 1H,1H,3H-hexafluorobutyl (meth) fluorine-containing monomers such as acrylates, 1,2,2,2-tetrafluoro-1-(trifluoromethyl)ethyl (meth)acrylate (excluding halogenated olefins);
Having an acetal structure such as 1-butoxyethyl (meth)acrylate, 1-(2-ethylhexyloxy)ethyl (meth)acrylate, 1-(cyclohexyloxy)ethyl methacrylate), 2-tetrahydropyranyl (meth)acrylate, etc. monomer;
other vinyl monomers such as 4-methacryloyloxybenzophenone, styrene, α-methylstyrene, vinyltoluene, (meth)acrylonitrile, vinyl chloride, vinyl acetate, vinyl propionate;
Among them, the monomer (a1) used in the macromonomer (a) includes methyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, and 2-methacrylate. Hydroxyethyl, isobornyl methacrylate, and cyclohexyl methacrylate are preferred from the viewpoint of increasing the holding power of the pressure-sensitive adhesive.

Monomer (a1) may be used alone or in combination of two or more.
When the vinyl monomer (b) does not contain the monomer (x), the monomer (a1) preferably contains the monomer (x). When the vinyl monomer (b) contains the monomer (x), the monomer (a1) may or may not contain the monomer (x).
At least part of the monomer (a1) is preferably a (meth)acrylic monomer.

As the structural unit derived from the monomer (a1), a structural unit represented by the following formula (a') (hereinafter also referred to as "structural unit (a')") is preferable. That is, the macromonomer (a) preferably has a radically polymerizable group and two or more structural units (a').

（式中、Ｒ^１は水素原子、メチル基又はＣＨ_２ＯＨを示し、Ｒ^２はＯＲ^３、ハロゲン原子、ＣＯＲ^４、ＣＯＯＲ^５、ＣＮ、ＣＯＮＲ^６Ｒ^７、ＮＨＣＯＲ^８又はＲ^９を示し、
Ｒ^３～Ｒ^８はそれぞれ独立に、水素原子、非置換の若しくは置換基を有するアルキル基、非置換の若しくは置換基を有する脂環式基、非置換の若しくは置換基を有するアリール基、非置換の若しくは置換基を有するヘテロアリール基、非置換の若しくは置換基を有する非芳香族の複素環式基、非置換の若しくは置換基を有するアラルキル基、非置換の若しくは置換基を有するアルカリール基、非置換の若しくは置換基を有するオルガノシリル基、非置換の若しくは置換基を有する（ポリ）オルガノシロキサン基を示し、これらの基における置換基はそれぞれ、アルキル基、アリール基、ヘテロアリール基、非芳香族の複素環式基、アラルキル基、アルカリール基、カルボン酸基（ＣＯＯＨ）、カルボン酸エステル基、エポキシ基、ヒドロキシ基、アルコキシ基、１級アミノ基、２級アミノ基、３級アミノ基、イソシアナト基、スルホン酸基（ＳＯ_３Ｈ）、カルボジイミド基、酸無水物基及びハロゲン原子からなる群から選ばれる少なくとも１種であり、Ｒ^９は非置換の若しくは置換基を有するアリール基、非置換の若しくは置換基を有するヘテロアリール基、又は非置換の若しくは置換基を有する非芳香族の複素環式基を示し、これらの基における置換基はそれぞれ、アルキル基、アリール基、ヘテロアリール基、非芳香族の複素環式基、アラルキル基、アルカリール基、カルボン酸基、カルボン酸エステル基、エポキシ基、ヒドロキシ基、アルコキシ基、１級アミノ基、２級アミノ基、３級アミノ基、イソシアナト基、スルホン酸基、非置換の若しくは置換基を有するオレフィン基及びハロゲン原子からなる群から選ばれる少なくとも１種である。）

(wherein R ¹ represents a hydrogen atom, a methyl group or CH ₂ OH, R ² represents OR ³ , a halogen atom, COR ⁴ , COOR ⁵ , CN, CONR ⁶ R ⁷ , NHCOR ⁸ or R ⁹ ,
R ³ to R ⁸ are each independently a hydrogen atom, an unsubstituted or substituted alkyl group, an unsubstituted or substituted alicyclic group, an unsubstituted or substituted aryl group, an unsubstituted or substituted heteroaryl group, unsubstituted or substituted non-aromatic heterocyclic group, unsubstituted or substituted aralkyl group, unsubstituted or substituted alkaryl group, represents an unsubstituted or substituted organosilyl group, an unsubstituted or substituted (poly)organosiloxane group, and the substituents in these groups are respectively an alkyl group, an aryl group, a heteroaryl group, a non-aromatic heterocyclic group, aralkyl group, alkaryl group, carboxylic acid group (COOH), carboxylic acid ester group, epoxy group, hydroxy group, alkoxy group, primary amino group, secondary amino group, tertiary amino group, is at least one selected from the group consisting of an isocyanato group, a sulfonic acid group ₍ SO3H), a carbodiimide group, an acid anhydride group and a halogen atom, and ^R9 is an unsubstituted or substituted aryl group, unsubstituted or a substituted heteroaryl group, or an unsubstituted or substituted non-aromatic heterocyclic group, wherein the substituents in these groups are alkyl groups, aryl groups, heteroaryl groups, non- Aromatic heterocyclic group, aralkyl group, alkaryl group, carboxylic acid group, carboxylic acid ester group, epoxy group, hydroxy group, alkoxy group, primary amino group, secondary amino group, tertiary amino group, isocyanato group , a sulfonic acid group, an unsubstituted or substituted olefin group and a halogen atom. )

unsubstituted alkyl group, unsubstituted alicyclic group, unsubstituted aryl group, unsubstituted heteroaryl group, unsubstituted non-aromatic heterocyclic group, unsubstituted aralkyl group for R ³ to R ⁸ , unsubstituted alkaryl group, unsubstituted organosilyl group, and unsubstituted (poly)organosiloxane group are the same as those described above for R. The unsubstituted aryl group, unsubstituted heteroaryl group, and unsubstituted non-aromatic heterocyclic group for R ⁹ are the same as those described above for R, respectively.

Substituents for R ³ to R ⁸ (substituted alkyl group, substituted alicyclic group, substituted aryl group, substituted heteroaryl group, substituted non-aromatic heterocyclic ring formula group, substituted aralkyl group, substituted alkaryl group, substituted organosilyl group), alkyl group, aryl group, heteroaryl group, non-aromatic heterocyclic Examples of groups, aralkyl groups, alkaryl groups and halogen atoms are the same as those described above.
As the carboxylic acid ester group, for example, R ¹¹ of -COOR ¹¹ is an unsubstituted or substituted alkyl group, an unsubstituted or substituted alicyclic group, or an unsubstituted or substituted aryl group. A group is a group.
Examples of alkoxy groups include groups wherein R ¹² of —OR ¹² is an unsubstituted alkyl group.
As the secondary amino group, R ¹³ of —NR ¹³ R ¹⁴ is a hydrogen atom, R ¹⁴ is an unsubstituted or substituted alkyl group, an unsubstituted or substituted alicyclic group, or an unsubstituted or an aryl group having a substituent.
As the tertiary amino group, R ¹³ and R ¹⁴ of —NR ¹³ R ¹⁴ are each an unsubstituted or substituted alkyl group, an unsubstituted or substituted alicyclic group, or an unsubstituted or A group that is an aryl group having a substituent is included.

Examples of the unsubstituted aryl group, unsubstituted heteroaryl group, and unsubstituted non-aromatic heterocyclic group for R ⁹ are the same as those described above.
Of the substituents for R ⁹ (substituted aryl group, substituted heteroaryl group, substituted non-aromatic heterocyclic group), an alkyl group, an aryl group, and a heteroaryl group , a non-aromatic heterocyclic group, an aralkyl group, an alkaryl group, a carboxylic acid ester group, an alkoxy group, a primary amino group, a secondary amino group, a tertiary amino group, and a halogen atom are the same as defined above. is mentioned.
Examples of unsubstituted olefin groups include allyl groups.
Examples of substituents in the substituted olefin group include those similar to those for R ⁹ .

Structural unit (a') is a structural unit derived from CH ₂ =CR ¹ R ² .
CH ₂ =CR ¹ R ² may be a monomer (x) or a monomer (y). You may use them together.
Specific examples of CH ₂ =CR ¹ R ² which is the monomer (x) include the following.
(Meth)acrylamide, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, Nt-butyl (meth)acrylamide, Nt-octyl (meth) ) acrylamide, N-methylol (meth)acrylamide, hydroxyethyl (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide, diacetone (meth)acrylamide, N,N-dimethylaminoethyl (Meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, N-vinylacetamide, N,N'-methylenebis(meth)acrylamide, (meth)acryloylmorpholine, N-vinylpyrrolidone, N-vinyl-ε - Caprolactam and the like.

Specific examples of CH ₂ =CR ¹ R ² which is the monomer (y) include the following. It may be a structural unit formed by converting R ^{2 of the structural unit into another R 2 .}
substituted or unsubstituted alkyl (meth)acrylates [e.g. methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i - butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 1-methyl-2-methoxyethyl ( meth)acrylate, 3-methoxybutyl (meth)acrylate, 3-methyl-3-methoxybutyl (meth)acrylate], substituted or unsubstituted aralkyl (meth)acrylates [e.g. benzyl (meth)acrylate, m-methoxyphenyl ethyl (meth)acrylate, p-methoxyphenylethyl (meth)acrylate], substituted or unsubstituted aryl (meth)acrylates [e.g. phenyl (meth)acrylate, m-methoxyphenyl (meth)acrylate, p-methoxyphenyl ( meth)acrylate, o-methoxyphenylethyl (meth)acrylate], alicyclic (meth)acrylate [e.g. isobornyl (meth)acrylate, cyclohexyl (meth)acrylate], halogen atom-containing (meth)acrylate [e.g. trifluoro Ethyl (meth) acrylate, perfluorooctyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate] hydrophobic group-containing (meth) acrylic acid ester monomer;
2-Methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, butoxydiethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate , phenoxyethyl (meth) acrylate, 2-(2-ethylhexaoxy) ethyl (meth) acrylate group-containing (meth) acrylic acid ester monomer;
2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, hydroxyl group-containing (meth) acrylic acid ester monomers such as glycerol (meth) acrylate;
Terminal alkoxyallylated polyethers such as methoxy polyethylene glycol allyl ether, methoxy polypropylene glycol allyl ether, butoxy polyethylene glycol allyl ether, butoxy polypropylene glycol allyl ether, methoxy polyethylene glycol-polypropylene glycol allyl ether, butoxy polyethylene glycol-polypropylene glycol allyl ether, etc. Ammer;
epoxy group-containing vinyl monomers such as glycidyl (meth)acrylate, glycidyl α-ethyl acrylate, and 3,4-epoxybutyl (meth)acrylate;
primary or secondary amino group-containing vinyl monomers such as butylaminoethyl (meth)acrylate;
Tertiary amino group-containing vinyl monomers such as dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, dimethylaminobutyl (meth)acrylate, and dibutylaminoethyl (meth)acrylate ;
Heterocyclic basic monomers such as vinylpyridine and vinylcarbazole;
trimethylsilyl (meth)acrylate, triethylsilyl (meth)acrylate, tri-n-propylsilyl (meth)acrylate, tri-n-butylsilyl (meth)acrylate, tri-n-amylsilyl (meth)acrylate, tri-n-hexylsilyl (Meth)acrylate, tri-n-octylsilyl (meth)acrylate, tri-n-dodecylsilyl (meth)acrylate, triphenylsilyl (meth)acrylate, tri-p-methylphenylsilyl (meth)acrylate, tribenzylsilyl (Meth) acrylate, triisopropylsilyl (meth) acrylate, triisobutylsilyl (meth) acrylate, tri-s-butylsilyl (meth) acrylate, tri-2-methylisopropylsilyl (meth) acrylate, tri-t-butylsilyl (meth) ) acrylate, ethyldimethylsilyl (meth)acrylate, n-butyldimethylsilyl (meth)acrylate, diisopropyl-n-butylsilyl (meth)acrylate, n-octyldi-n-butylsilyl (meth)acrylate, diisopropylstearylsilyl (meth)acrylate , dicyclohexylphenylsilyl (meth)acrylate, t-butyldiphenylsilyl (meth)acrylate, organosilyl group-containing vinyl monomers such as lauryldiphenylsilyl (meth)acrylate;
Methacrylic acid, acrylic acid, vinyl benzoic acid, monohydroxyethyl tetrahydrophthalate (meth)acrylate, monohydroxypropyl tetrahydrophthalate (meth)acrylate, monohydroxybutyl tetrahydrophthalate (meth)acrylate, monohydroxyethyl phthalate (meth)acrylate ) acrylate, monohydroxypropyl phthalate (meth)acrylate, monohydroxyethyl succinate (meth)acrylate, monohydroxypropyl succinate (meth)acrylate, monohydroxyethyl maleate (meth)acrylate, monohydroxypropyl maleate (meth)acrylate ) carboxy group-containing ethylenically unsaturated monomers such as acrylates;
cyano group-containing vinyl monomers such as acrylonitrile and methacrylonitonyl;
vinyl ether monomers such as alkyl vinyl ethers [e.g., ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, 2-ethylhexyl vinyl ether, etc.], cycloalkyl vinyl ethers [e.g., cyclohexyl vinyl ether, etc.];
vinyl ester monomers such as vinyl acetate, vinyl propionate, vinyl butyrate, and vinyl benzoate;
aromatic vinyl monomers such as styrene, vinyltoluene, α-methylstyrene;
halogenated olefins such as vinyl chloride and vinyl fluoride;

The macromonomer (a) may further have structural units other than the structural unit (a'). Other structural units include, for example, structural units derived from monomers not corresponding to CH ₂ =CR ¹ R ² among the monomers exemplified for the monomer (a1) described above.
Preferred specific examples of other structural units include structural units derived from the following monomers.
triisopropylsilylmethylmalate, triisopropylsilylamylmalate, tri-n-butylsilyl-n-butylmalate, t-butyldiphenylsilylmethylmalate, t-butyldiphenylsilyl-n-butylmalate, triisopropylsilylmethylfumarate, Organosilyl group-containing vinyl monomers such as triisopropylsilyl amyl fumarate, tri-n-butylsilyl-n-butyl fumarate, t-butyldiphenylsilylmethyl fumarate, t-butyldiphenylsilyl-n-butyl fumarate;
Acid anhydride group-containing vinyl monomers such as maleic anhydride and itaconic anhydride;
Crotonic acid, fumaric acid, itaconic acid, maleic acid, citraconic acid, monomethyl maleate, monoethyl maleate, monobutyl maleate, monooctyl maleate, monomethyl itaconate, monoethyl itaconate, monobutyl itaconate, monooctyl itaconate, fumar Carboxy group-containing ethylenically unsaturated monomers such as monomethyl acid, monoethyl fumarate, monobutyl fumarate, monooctyl fumarate, and monoethyl citraconate;
Unsaturated dicarboxylic acid diester monomers such as dimethylmalate, dibutylmalate, dimethylfumarate, dibutylfumarate, dibutylitaconate, diperfluorocyclohexylfumarate;
Halogenated olefins such as vinylidene chloride, vinylidene fluoride, chlorotrifluoroethylene;
Ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol Di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol polyfunctional monomers such as tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, allyl methacrylate, triallyl cyanurate, diallyl maleate, polypropylene glycol diallyl ether;

The content of structural units derived from the macromonomer (a) is preferably 3 to 60% by mass, preferably 7 to 40% by mass, and 8 to 30% by mass with respect to the total mass (100% by mass) of all structural units. More preferably, 9 to 20% by mass is even more preferable.
When the content of the structural unit derived from the macromonomer (a) is 3% by mass or more relative to the total weight of all structural units, the adhesive layer has a good holding power, and when it is 60% by mass or less, the adhesive layer is Better adhesion.

The macromonomer (a) preferably contains 50% by mass or more of structural units derived from (meth)acrylic monomers with respect to the total mass (100% by mass) of all structural units constituting the macromonomer (a). , more preferably 70% by mass or more. The upper limit is not particularly limited, and may be 100% by mass.
As a structural unit derived from a (meth)acrylic monomer, a structural unit in which R ¹ in the formula (a′) is a hydrogen atom or a methyl group and R ² is COOR ⁵ is preferable.

As the macromonomer (a), a macromonomer in which a radically polymerizable group is introduced at the end of a main chain containing two or more structural units (a′) is preferable, and a macromonomer represented by the following formula (1) is more preferable. preferable.

（式中、Ｒは水素原子、非置換の若しくは置換基を有するアルキル基、非置換の若しくは置換基を有する脂環式基、非置換の若しくは置換基を有するアリール基、非置換の若しくは置換基を有するへテロアリール基、非置換の若しくは置換基を有する非芳香族の複素環式基、非置換の若しくは置換基を有するアラルキル基、非置換の若しくは置換基を有するアルカリール基、非置換の若しくは置換基を有するオルガノシリル基、又は非置換の若しくは置換基を有する（ポリ）オルガノシロキサン基を示し、Ｑは２以上の構成単位（ａ’）を含む主鎖部分を示し、Ｚは末端基を示す。）

(wherein R is a hydrogen atom, an unsubstituted or substituted alkyl group, an unsubstituted or substituted alicyclic group, an unsubstituted or substituted aryl group, an unsubstituted or substituted heteroaryl group, unsubstituted or substituted non-aromatic heterocyclic group, unsubstituted or substituted aralkyl group, unsubstituted or substituted alkaryl group, unsubstituted or An organosilyl group having a substituent, or an unsubstituted or substituted (poly)organosiloxane group, Q represents a main chain portion containing two or more structural units (a'), and Z represents a terminal group. show.)

In formula (1), R is the same as R in CH ₂ ═C(COOR)—CH ₂ — described above, and preferred embodiments are also the same.
Two or more structural units (a') contained in Q may be the same or different.
Q may consist only of the structural unit (a'), or may further contain other structural units other than the structural unit (a').
Q preferably includes a structural unit (a′) in which R ¹ is a hydrogen atom or a methyl group and R ² is COOR ⁵ in the formula (a′). The proportion of the structural unit is preferably 50% by mass or more, more preferably 70% by mass or more, and may be 100% by mass, relative to the total mass (100% by mass) of all the structural units constituting Q.
The number of structural units constituting Q can be appropriately set within the range that the number average molecular weight of the macromonomer (a) is within the above range.
Examples of Z include a hydrogen atom, a group derived from a radical polymerization initiator, a radically polymerizable group, and the like, as well as a terminal group of a polymer obtained by known radical polymerization.

As the macromonomer (a), a macromonomer represented by the following formula (2) is particularly preferred.

（式中、Ｒ及びＺは前記と同義であり、Ｒ^２１は水素原子又はメチル基を示し、Ｒ^２２は非置換の若しくは置換基を有するアルキル基、非置換の若しくは置換基を有する脂環式基、非置換の若しくは置換基を有するアリール基、非置換の若しくは置換基を有するヘテロアリール基、非置換の若しくは置換基を有するアラルキル基、非置換の若しくは置換基を有するアルカリール基、又は非置換の若しくは置換基を有するオルガノシリル基を示し、これらの基における置換基はそれぞれ、アルキル基、アリール基、ヘテロアリール基、非芳香族の複素環式基、アラルキル基、アルカリール基、カルボン酸基、カルボン酸エステル基、エポキシ基、ヒドロキシ基、アルコキシ基、１級アミノ基、２級アミノ基、３級アミノ基、イソシアナト基、スルホン酸基及びハロゲン原子からなる群から選ばれる少なくとも１種であり、ｎは２以上の自然数を示す。）

(Wherein, R and Z are as defined above, R ²¹ represents a hydrogen atom or a methyl group, R ²² represents an unsubstituted or substituted alkyl group, an unsubstituted or substituted alicyclic an unsubstituted or substituted aryl group, an unsubstituted or substituted heteroaryl group, an unsubstituted or substituted aralkyl group, an unsubstituted or substituted alkaryl group, or an unsubstituted represents a substituted or substituted organosilyl group, wherein the substituents in these groups are respectively alkyl, aryl, heteroaryl, non-aromatic heterocyclic, aralkyl, alkaryl, carboxylic acid at least one selected from the group consisting of a group, a carboxylic acid ester group, an epoxy group, a hydroxy group, an alkoxy group, a primary amino group, a secondary amino group, a tertiary amino group, an isocyanato group, a sulfonic acid group and a halogen atom; Yes, and n is a natural number of 2 or more.)

In formula (2), R and Z are the same as defined above.
Each group for R ²² is the same as those listed for R ⁵ of COOR ⁵ .
n is a natural number of 2 or more. n is within a range in which the number average molecular weight (Mn) of the macromonomer (a) is 500 or more and 100,000 or less. Preferred ranges for the number average molecular weight are as follows. Each of n R ²¹ may be the same or different. Each of n R ²² may be the same or different.

When the macromonomer (a) has the addition-reactive functional group and is added to the functional group of the polymer composed of structural units derived from the vinyl monomer (b), the macromonomer (a) preferably has one or more addition-reactive functional groups and two or more of the above structural units (a'). As the structural unit (a'), those similar to those used when the macromonomer (a) has a radically polymerizable group can be used.
In addition to the above macromonomer (a), a compound having a functional group can be added to the functional group of the polymer composed of structural units derived from the vinyl monomer (b). Examples of compounds having functional groups include X-22-173BX (manufactured by Shin-Etsu Chemical Co., Ltd., trade name), X-22-173DX (manufactured by Shin-Etsu Chemical Co., Ltd., trade name), X-22- 170BX (manufactured by Shin-Etsu Chemical Co., Ltd., trade name), X-22-170DX (manufactured by Shin-Etsu Chemical Co., Ltd., trade name), X-22-176DX (manufactured by Shin-Etsu Chemical Co., Ltd., trade name), Examples include silicone compounds such as X-22-176F (manufactured by Shin-Etsu Chemical Co., Ltd., trade name) and X-22-173GX-A (manufactured by Shin-Etsu Chemical Co., Ltd., trade name).

The number average molecular weight (Mn) of the macromonomer (a) is from 500 to 100,000, preferably from 800 to 30,000, more preferably from 900 to 10,000, and particularly preferably from 1,000 to 6,000. If the number average molecular weight of the macromonomer (a) is at least the lower limit of the above range, the adhesive layer will have better holding power. If the number average molecular weight of the macromonomer (a) is equal to or less than the upper limit of the above range, compatibility with other components, hot-melt processability, and the like when used as a pressure-sensitive adhesive composition are more excellent.
The number average molecular weight of macromonomer (a) is measured by gel permeation chromatography (GPC) using polystyrene as a reference resin.

The glass transition temperature (hereinafter also referred to as “Tga”) of the macromonomer (a) is preferably 0 to 150°C, more preferably 10 to 120°C, and even more preferably 30 to 100°C. When the Tga is at least the lower limit of the above range, the adhesive layer has better holding power. If Tga is equal to or less than the upper limit of the above range, the hot-melt processability is more excellent.
Tga can be measured with a differential scanning calorimeter (DSC).
Tga can be adjusted by adjusting the composition of the monomers forming the macromonomer (a).

As the macromonomer (a), one produced by a known method may be used, or a commercially available one may be used.
Methods for producing the macromonomer (a) having a radically polymerizable group include, for example, a method using a cobalt chain transfer agent, a method using an α-substituted unsaturated compound such as α-methylstyrene dimer as a chain transfer agent, Examples include a method using an initiator, a method of chemically bonding a radically polymerizable group to a polymer, and a method of thermal decomposition.
Among these, as a method for producing a macromonomer (a) having a radically polymerizable group, the number of production steps is small, and the chain transfer constant of the catalyst used is high. is preferred. The macromonomer (a) produced using a cobalt chain transfer agent has the structure represented by the formula (1).

Examples of methods for producing the macromonomer (a) using a cobalt chain transfer agent include bulk polymerization, solution polymerization, and aqueous dispersion polymerization methods such as suspension polymerization and emulsion polymerization. Aqueous dispersion polymerization is preferred because the recovery step is simple.
As a method of chemically bonding a radically polymerizable group to a polymer, for example, the halogen group of a polymer having a halogen group is substituted with a compound having a radically polymerizable carbon-carbon double bond. a method of reacting a vinyl monomer having an acid group with a vinyl polymer having an epoxy group; a method of reacting a vinyl polymer having an epoxy group with a vinyl monomer having an acid group; a method of reacting a vinyl polymer having an isocyanate group with a vinyl monomer having an isocyanate group, a method of reacting a vinyl polymer having an isocyanate group with a vinyl monomer having an acid group, a vinyl polymer having a hydroxyl group, A method of reacting the coalescence with a vinyl monomer having an isocyanate group, a method of reacting a vinyl polymer having an isocyanate group with a vinyl monomer having a hydroxyl group, and a method of reacting a vinyl polymer having a hydroxyl group with a diisocyanate compound. Examples include a method of reacting to obtain a vinyl polymer having an isocyanate group, and reacting the vinyl polymer with a vinyl monomer having a hydroxyl group, and any method may be used for production.
The number average molecular weight of the macromonomer (a) can be adjusted with a polymerization initiator, a chain transfer agent, and the like.

As a method for producing a macromonomer (a) having an addition-reactive functional group such as a hydroxyl group, an isocyanate group, an epoxy group, a carboxyl group, an amino group, an amide group, a thiol group, or a carbodiimide group, for example, A method of copolymerizing a vinyl monomer, a method of using a chain transfer agent such as mercaptoethanol, mercaptoacetic acid, mercaptopropionic acid, 2,2'-azobis (propane-2-carboamidine), 4,4'-azobis (4-cyanovaleric acid), 2,2′-azobis[N-(2-carboxyethyl)-2-methylpropionamidine], 2,2′azobis[2[1(2hydroxyethyl)2imidazoline2yl] propane] and the like using an initiator capable of introducing a functional group.

<Vinyl monomer (b)>
Vinyl monomer (b) is a monomer that has an ethylenically unsaturated bond and is not a macromonomer. The vinyl monomer (b) is not particularly limited, and the same monomers as the monomer (a1) for obtaining the macromonomer (a) can be used. Specific examples include monomer (x) and monomer (y). However, in the vinyl monomer (b), a vinyl monomer is used for each of the monomer (x) and the monomer (y). Any one of these vinyl monomers may be used, or two or more thereof may be used in combination.
When the macromonomer (a) does not contain a structural unit derived from the monomer (x), the vinyl monomer (b) contains the monomer (x). When the macromonomer (a) contains a structural unit derived from the monomer (x), the vinyl monomer (b) may or may not contain the monomer (x).
At least part of the monomer (b) is preferably a (meth)acrylic monomer.
When the macromonomer (a) is added to a polymer composed of structural units derived from the vinyl monomer (b), the vinyl monomer (b) has a functional group capable of reacting with the functional group of the macromonomer (a). It is suitable to contain things.
The composition of vinyl monomer (b) is typically different from the composition of the monomers that make up macromonomer (a). A composition shows the kind and content rate of a monomer.

From the viewpoints of adhesive strength, wet heat whitening resistance and low corrosion, it is preferable that a part of the vinyl monomer (b) is the monomer (x). That is, the vinyl monomer (b) preferably contains the monomer (x) and the monomer (y).

In the vinyl monomer (b), the monomer (y) is an alkyl (meth)acrylate having an unsubstituted alkyl group having 4 to 30 carbon atoms (hereinafter also referred to as "monomer (y1)"). preferable. The monomer (y1) can exhibit flexibility as an adhesive. Further, since the monomer (y1) is hydrophobic, the monomer (y1) can also suppress the water absorption rate and reduce the dielectric constant. Furthermore, when the copolymer (A) is used in a pressure-sensitive adhesive resin composition containing a polymerizable monofunctional compound, such as the pressure-sensitive adhesive resin composition (1) described later, the vinyl monomer (b) is a monomer By including the monomer (y1), the compatibility between the copolymer (A) and the polymerizable monofunctional compound is more excellent. That is, as the polymerizable monofunctional compound, a polymerizable monofunctional compound having a hydrocarbon group with 4 or more carbon atoms is often used, although the details will be described later. Since the monomer (y1) has an alkyl group having 4 to 30 carbon atoms, compatibility is enhanced when the copolymer (A) contains structural units derived from the monomer (y1). If the compatibility between the copolymer (A) and the polymerizable monofunctional compound is high, the transparency of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive resin composition is further enhanced, and optical transparency such as OCA and LOCA is required. It is useful in applications where

Specific examples of the monomer (y1) include n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, and (meth)acrylic nonyl acid, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, hexadecyl (meth)acrylate, stearyl (meth)acrylate, (meth)acrylic acid isostearyl, behenyl (meth)acrylate, and the like.
The number of carbon atoms in the alkyl group of the monomer (y1) is 4-30, preferably 8-30, particularly preferably 9-18.

The vinyl monomer (b) may further contain vinyl monomers other than the monomer (x) and the monomer (y1), if necessary. Other vinyl monomers can be appropriately selected from the above-mentioned monomers (y).
For example, from the viewpoint of increasing the cohesive strength of the pressure-sensitive adhesive, as other vinyl monomers, one or more monomers selected from the group consisting of methyl (meth)acrylate and ethyl (meth)acrylate may be included. can.
Other preferred vinyl monomers include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, styrene, isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, Tetrahydrofurfuryl (meth)acrylate and the like can be mentioned.

The vinyl monomer (b) is a polymer obtained by polymerizing only the vinyl monomer (b) (hereinafter also referred to as "polymer (B)") and the macromonomer (a). It is preferable to have a composition that makes a difference. If there is a difference in polarity between the polymer (B) and the macromonomer (a), when an adhesive layer or coating film is formed, the polymer chains of the macromonomer (a) and the polymer (B) form The polymer chains are microphase-separated, and each characteristic tends to be sufficiently expressed. For example, the effect of improving the holding power of the adhesive layer by the macromonomer (a) is sufficiently exhibited, and the holding power of the adhesive layer is excellent.
For example, when the macromonomer (a) contains a structural unit derived from methyl methacrylate, the vinyl monomer (b) preferably contains the monomer (y1). Since the monomer (y1) has a large number of carbon atoms in the alkyl group, it is less polar than methyl methacrylate. The inclusion of monomer (y1) creates a polarity difference between polymer (B) and macromonomer (a).
In this case, the ratio of the structural unit derived from methyl methacrylate to the total of all structural units constituting the macromonomer (a) is preferably 50% by mass or more, more preferably 75% by mass or more. Further, the ratio of the monomer (y1) to the total amount of the vinyl monomer (b) is preferably 30% by mass or more, more preferably 60% by mass or more, still more preferably 80% by mass or more, and 90% by mass or more. Especially preferred. The greater the proportion of the structural unit derived from methyl methacrylate in the macromonomer (a), or the greater the proportion of the monomer (y1) in the vinyl monomer (b), the greater the proportion of the polymer (B) and the macromonomer (a ) becomes large, and microphase separation is likely to occur.

The vinyl monomer (b) preferably has a composition such that the polymer (B) obtained by polymerizing only the vinyl monomer (b) has a glass transition temperature (TgB) of -100 to 10°C. TgB is preferably -65 to 0°C, more preferably -60 to -10°C. If the TgB is within the above range, the resin composition for pressure-sensitive adhesive containing the copolymer (A) has appropriate flexibility and tackiness.

TgB is the glass transition temperature of a homopolymer of the vinyl monomer when the number of vinyl monomers (b) is one, and when the number of vinyl monomers (b) is two or more, It means a value calculated by the Fox formula from the glass transition temperature and mass fraction of homopolymer of each vinyl monomer.
The Fox calculation formula is a calculated value obtained by the following formula, which is described in Polymer Handbook [Polymer Handbook, J. Am. Brandrup, Interscience, 1989] (Tg in the formula corresponds to TgB).
1/(273+Tg)=Σ(Wi/(273+Tgi))
(Wherein, Wi is the mass fraction of the monomer i, and Tgi is the glass transition temperature (°C) of the homopolymer of the monomer i.)

The above-mentioned Tga and TgB have the relationship of the following formula (3) from the point that the respective characteristics of the macromonomer (a) portion and the portion composed of the structural unit derived from the vinyl monomer (b) can be sufficiently expressed. is preferred. That is, it is preferable that Tga-TgB>0.degree.
Tga>TgB (3)
More preferably Tga-TgB≧50°C, most preferably Tga-TgB≧80°C.

<Content of each structural unit>
The content of the structural unit derived from the macromonomer (a) in the copolymer (A) is preferably 3 to 60% by mass with respect to the total mass of all structural units constituting the copolymer (A), and 7 to 40% by mass is more preferable, 8 to 30% by mass is even more preferable, and 9 to 20% by mass is particularly preferable. When the content of the structural unit derived from the macromonomer (a) is at least the lower limit of the above range, the adhesive layer has better holding power. When the content of the structural unit derived from the macromonomer (a) is equal to or less than the upper limit of the above range, the compatibility with other components and the hot-melt processability when formed into a blend are more excellent.

The content of the structural unit derived from the vinyl monomer (b) in the copolymer (A) is preferably 40 to 97% by mass with respect to the total weight of all structural units constituting the copolymer (A), 60 to 93% by mass is more preferable, 70 to 92% by mass is even more preferable, and 80 to 91% by mass is particularly preferable. When the content of the structural unit derived from the vinyl monomer (b) is at least the lower limit of the above range, the compatibility with other components and the hot-melt processability when made into a blend are more excellent. When the content of the structural unit derived from the vinyl monomer (b) is equal to or less than the upper limit of the above range, the adhesive layer has better holding power.

The content of the constituent units derived from the monomer (x) in the copolymer (A) is preferably 0.1 to 30% by mass with respect to the total weight of all constituent units constituting the copolymer (A). , more preferably 1.0 to 20 mass %, still more preferably 2.0 to 10 mass %, and particularly preferably 2.0 to 4.8. Therefore, the content of structural units derived from the monomer (y) is preferably 70 to 99.9% by mass, more preferably 80 to 99% by mass, and 90 to 98% by mass, based on the total mass of all structural units. is more preferred, and 95.2 to 98% by mass is particularly preferred.
If the content of the structural unit derived from the monomer (x) is at least the lower limit of the range (the content of the structural unit derived from the monomer (y) is at most the upper limit of the range), the moisture resistance of the adhesive layer Better thermal whitening resistance. If the content of the constituent units derived from the monomer (x) is equal to or lower than the upper limit of the range (the content of the constituent units derived from the monomer (y) is equal to or higher than the lower limit of the range), the mixture was treated as a formulation. compatibility with other components and hot-melt processability are better.

The content of the structural unit derived from the monomer (x) in the structural unit derived from the vinyl monomer (b) is based on the total mass (100% by mass) of the structural units derived from the vinyl monomer (b). 0.1 to 75% by mass is preferable, 1.0 to 50% by mass is more preferable, 2.0 to 25% by mass is still more preferable, and 2.0 to 12% by mass is particularly preferable. If the content of the structural unit derived from the monomer (x) is at least the lower limit of the above range, the adhesive layer will have more excellent wet heat whitening resistance and low corrosion resistance. If the content of the structural unit derived from the monomer (x) is equal to or less than the upper limit of the above range, the compatibility with other components and the hot-melt processability when formed into a blend are more excellent.

The content of the structural unit derived from the carboxyl group-containing vinyl monomer in the copolymer (A) is preferably 0.5% by mass or less with respect to the total mass of all structural units constituting the copolymer (A). , 0.1% by mass or less is more preferable. The lower limit is not particularly limited, and may be 0% by mass. If the content of the structural unit derived from the carboxyl group-containing vinyl monomer is equal to or less than the above upper limit, the low corrosiveness is more excellent.

The content of the structural unit derived from the hydroxyl group-containing vinyl monomer in the copolymer (A) is preferably 20% by mass or less, more preferably 10% by mass, based on the total amount of all structural units constituting the copolymer (A). The following are more preferable, and 5% by mass or less is even more preferable. The lower limit is not particularly limited, and may be 0% by mass. If the content of the structural unit derived from the hydroxyl group-containing vinyl monomer is equal to or less than the above upper limit, compatibility with other components when made into a compound, hot-melt processability, or removal of the copolymer (A). It is excellent in terms of suppression of thickening when used as a solvent.

<Properties of copolymer (A)>
The weight average molecular weight (Mw) of the copolymer (A) is preferably 20,000 to 1,000,000, more preferably 50,000 to 700,000, still more preferably 80,000 to 500,000, and more preferably 80,000 to 300,000. 80,000 to 250,000 is particularly preferable. When the weight-average molecular weight of the copolymer (A) is at least the lower limit of the above range, the adhesive layer using the resin composition for an adhesive containing the copolymer (A) tends to have good holding power. . When the weight-average molecular weight of the copolymer (A) is at most the upper limit of the above range, the coating properties of the adhesive resin composition and the coating composition containing the copolymer (A) tend to be good. .
The weight average molecular weight of the copolymer (A) is a standard polystyrene-equivalent value measured by gel permeation chromatography (GPC). Specifically, it is measured by the method described in the examples below.

From the viewpoint of low corrosion, the acid value of the copolymer (A) is preferably 3.9 mgKOH/g or less, more preferably 0.8 mgKOH/g or less. The lower limit is not particularly limited, and may be 0 mgKOH/g.
The acid value is determined by weighing 0.5 g of a sample in a beaker (A (g)), adding 50 mL of a toluene/95% ethanol solution and several drops of phenolphthalein, and titrating with a 0.5 M potassium hydroxide solution. Measured in (Titration volume = B (mL), titer of potassium hydroxide solution = f, blank measurement is performed in the same manner (titration volume C (mL) is calculated by the following formula.
Acid value (mgKOH/g) = {(BC) x 0.2 x 56.11 x f}/A/solid content)
When the acid value of the copolymer (A) is within this range, corrosion hardly occurs when the adhesive layer using the resin composition for adhesive is adhered to a metal electrode or the like.

When the copolymer (A) is a 50% by mass ethyl acetate solution, the viscosity measured with a Brookfield viscometer at 25 ° C. (hereinafter also referred to as "solution viscosity") is 10 to 800,000 mPa · s is preferred, 100 to 10,000 mPa·s is more preferred, and 100 to 7,000 mPa·s is even more preferred. If the solution viscosity is at least the lower limit of the above range, the holding power of the pressure-sensitive adhesive layer will be better, and the substrate staining property will be lower. When the solution viscosity is equal to or less than the upper limit of the above range, the coatability, the compatibility with other components when used as a compound, and the hot-melt processability are more excellent.

The copolymer (A) may or may not have a crosslinked structure. It does not have a crosslinked structure in terms of the applicability of the copolymer (A) and the pressure-sensitive adhesive resin composition containing it, compatibility with other components when formulated, and hot-melt processability. is preferred.

<Method for producing copolymer (A)>
Examples of the method for producing the copolymer (A) include the following production methods (α) and (β). The copolymer (A) may be produced by the production method (α) or may be produced by the production method (β). However, the method for producing the copolymer (A) is not limited to these.
Production method (α): A method of using a macromonomer having a radically polymerizable group as the macromonomer (a) and copolymerizing this macromonomer (a) with a vinyl monomer (b).
Production method (β): As the macromonomer (a), a macromonomer having the addition-reactive functional group is used, and the macromonomer (a) has a functional group capable of reacting with the addition-reactive functional group. A method of reacting with a polymer composed of structural units derived from a vinyl monomer (b) containing a vinyl monomer.

As the method for producing the copolymer (A), the production method (α) is preferred. That is, the copolymer (A) is preferably a copolymer of the macromonomer (a) and the vinyl monomer (b). In such a copolymer, structural units derived from the macromonomer (a) and structural units derived from the vinyl monomer (b) are randomly arranged. In other words, polymer chains derived from one or more macromonomers (a) are bound throughout the main chain of copolymer (A). Such a polymer is, for example, a case where the structural unit derived from the macromonomer (a) is bound only to the end of the polymer chain composed of the structural unit derived from the vinyl monomer (b)), compared to the adhesiveness Layer retention tends to be better.

(Manufacturing method (α))
The preferred range of the composition of the monomers to be polymerized in the production method (α), that is, the content (mass%) of each monomer with respect to the total mass of the types of monomers to be polymerized and the total mass of all monomers (amount charged) , The composition of the copolymer (A), that is, the type of structural units derived from the monomers constituting the copolymer (A) and the content (% by mass) of each structural unit with respect to the total mass of all structural units be.
For example, the content of the macromonomer (a) with respect to the total mass (100% by mass) of all monomers to be polymerized is preferably 3 to 60% by mass, more preferably 7 to 40% by mass, and even more preferably 7 to 30% by mass. , 9 to 20% by weight are particularly preferred.

Polymerization of the monomer may be carried out by a known method using a known polymerization initiator. For example, a method of reacting the macromonomer (a) and the vinyl monomer (b) in the presence of a radical polymerization initiator at a reaction temperature of 60 to 120° C. for 1 to 14 hours can be mentioned. A chain transfer agent may be used during the polymerization, if desired.
As the polymerization method, for example, known polymerization methods such as solution polymerization method, suspension polymerization method, bulk polymerization method and emulsion polymerization method can be applied. From the viewpoint of drying property in the film-forming process and coating film performance, it is preferable that the resin composition for pressure-sensitive adhesive containing the copolymer (A) does not contain water. The water content in the adhesive resin composition is preferably 10% by mass or less, more preferably 5% by mass or less, and most preferably 1% by mass or less. The water content in the adhesive resin composition can be measured by the volumetric Karl Fischer method. Furthermore, in order to reduce the amount of water in the pressure-sensitive adhesive resin composition, it is preferable not to include water during the production process of the copolymer (A). The water content during the production process of the copolymer (A) is preferably 10% by mass or less, more preferably 5% by mass or less, most preferably 1% by mass or less, and may be 0% by mass. A solution polymerization method is preferable as a production method that does not involve water in the production process of the copolymer (A).
Solution polymerization can be carried out, for example, by supplying a polymerization solvent, a monomer and a radical polymerization initiator into a polymerization vessel and maintaining a predetermined reaction temperature. The total amount of the monomers may be charged into the polymerization vessel in advance (before the inside of the polymerization vessel is brought to a predetermined reaction temperature), or may be dropped after the inside of the polymerization vessel is brought to a prescribed reaction temperature, or It may be prepared in advance in a polymerization vessel and the remainder may be supplied dropwise.

The copolymer (A) has a structural unit derived from the macromonomer (a) and a structural unit derived from the vinyl monomer (b), and the structural unit possessed by the macromonomer (a) and the vinyl monomer Since at least part of the constituent units derived from the body (b) has an amide bond, it is possible to form an adhesive layer with excellent wet heat whitening resistance and low corrosion resistance. In addition, the adhesive layer has sufficiently excellent adhesive strength.

Conventional (meth)acrylic copolymers for adhesive resin compositions often contain structural units having carboxyl groups. By including a carboxyl group, the cohesive force of the copolymer increases, and the adhesive force and holding power of the adhesive layer increase. In addition, since the carboxyl group is a hydrophilic group, the affinity between the copolymer and water is enhanced, and when exposed to a high-temperature and high-humidity atmosphere, whitening due to aggregation of water in the adhesive layer is less likely to occur. . However, carboxyl groups are acidic and cause corrosion.
Since the copolymer (A) has an amide bond, it has a sufficiently high affinity with water even if it does not contain a carboxyl group, and whitening is suppressed. In addition, since some of the structural units are introduced into the copolymer as a macromonomer (a), a sufficiently high cohesive force can be obtained without containing a carboxyl group, and excellent adhesive strength and holding power can be obtained. It is obtained and also makes whitening less likely to occur.
In particular, by including a structural unit having no amide bond together with a structural unit having an amide bond, more excellent adhesive strength and holding power can be easily obtained.
Therefore, the copolymer (A) can be made less corrosive by reducing the content of carboxyl groups while sufficiently maintaining wet heat whitening resistance, adhesive strength, and holding power. Furthermore, in the copolymer (A), compared to a copolymer obtained by copolymerizing the monomers constituting the macromonomer (a) and the vinyl monomer (b) in the same composition ratio, , the holding power of the adhesive layer is better.
The reason why the above effect can be obtained by using the macromonomer (a) is that when forming the adhesive layer, it is composed of a polymer chain derived from the macromonomer (a) and a structural unit derived from the vinyl monomer (b). It is conceivable that the polymer chains formed therefrom undergo microphase separation to form a sea-island structure, and the properties of each polymer chain are fully exhibited.

Thus, the adhesive layer using the adhesive resin composition containing the copolymer (A) is excellent in wet heat whitening resistance, and thus sufficiently maintains transparency even when exposed to a high humidity and high temperature environment. It can be used for applications requiring transparency, such as lamination of a display surface of a display device and a transparent substrate. In addition, because of its low corrosiveness, it can be used in applications where it is in direct contact with members that may corrode, such as electrodes made of metals or metal oxides (such as ITO). Moreover, since the holding force is excellent, problems such as misalignment of the bonded members are less likely to occur after the members are bonded together via the adhesive layer.

Because of the above effects, the copolymer (A) is useful as a resin composition for pressure-sensitive adhesives, and is particularly suitable for pressure-sensitive adhesive sheets.
However, the use of the adhesive resin composition containing the copolymer (A) is not limited to the above, and it can be used for other uses. Other uses include, for example, coating compositions, adhesive compositions, molding material compositions, and film compositions.

[Resin composition for adhesive]
The adhesive resin composition of the present invention contains the copolymer (A).
The copolymer (A) contained in the adhesive resin composition may be of one type or two or more types.
The pressure-sensitive adhesive resin composition of the present invention may be composed of the (meth)acrylic copolymer (A) alone, or may contain other components as necessary.

<Polymerizable monofunctional compound>
The adhesive resin composition of the present invention can further contain a polymerizable monofunctional compound having one radically polymerizable group, if necessary.
Examples of the radically polymerizable group in the polymerizable monofunctional compound include those described above, and a (meth)acryloyl group is preferred. That is, the polymerizable monofunctional compound is preferably a monofunctional (meth)acrylate having one (meth)acryloyl group.

As the polymerizable monofunctional compound, the same monomers as those for obtaining the macromonomer (a) can be used.
As the polymerizable monofunctional compound, a polymerizable monofunctional compound having a hydrocarbon group with 4 or more carbon atoms is preferable from the viewpoint of flexibility as an adhesive. Examples of the hydrocarbon group include an alkyl group, an aryl group, an aralkyl group and the like. The number of carbon atoms in the hydrocarbon group is more preferably 8-30.

When the resin composition for pressure-sensitive adhesive of the present invention is used as a liquid pressure-sensitive adhesive resin composition, the polymerizable monofunctional compound preferably functions as a reactive diluent. A polymerizable monofunctional compound that is liquid at 25° C. is typically used as the polymerizable monofunctional compound that functions as a reactive diluent. As such a polymerizable monofunctional compound, those similar to the monomer for obtaining the macromonomer (a) can be used. Any one of these polymerizable monofunctional compounds can be used alone. Well, you may use 2 or more types together.

Polymerizable monofunctional compounds include isodecyl (meth)acrylate, isostearyl (meth)acrylate, ethylhexyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, isononyl (meth)acrylate, n-octyl At least one selected from the group consisting of (meth)acrylate, isooctyl (meth)acrylate and lauryl acrylate is particularly preferred.

<Oligomer component>
The pressure-sensitive adhesive resin composition of the present invention may further contain an oligomer component, if necessary.
Examples of oligomer components include urethane-based oligomers, polyester-based oligomers, acrylic oligomers, polyether-based oligomers, polyolefin-based oligomers, and the like. These may have a reactive double bond, may have a functional group and may react with other components in the adhesive resin composition, or may not react with other components.

<Crosslinking agent>
The resin composition for pressure-sensitive adhesive of the present invention may further contain a cross-linking agent, if necessary. When the resin composition for pressure-sensitive adhesive contains a cross-linking agent, the resin composition for pressure-sensitive adhesive can be cured (cross-linked) to increase the cross-linking density of the pressure-sensitive adhesive layer. As a result, the strength, holding power, etc. of the adhesive layer tend to be more excellent. In addition, depending on the application, it is not necessary to include a cross-linking agent. Further, when the copolymer (A) has self-crosslinking properties, for example, when it has both hydroxyl groups and isocyanato groups, sufficient strength, holding power, etc. can be obtained without containing a cross-linking agent.
Examples of cross-linking agents include isocyanate-based, epoxy-based, metal chelate-based, photocuring-based, melamine-based, and aziridine-based agents. Any one of these cross-linking agents may be used alone, or two or more thereof may be used in combination.

Examples of isocyanate-based cross-linking agents include aromatic polyisocyanates such as xylylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate and tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated products of the above aromatic polyisocyanates, and the like. aliphatic or alicyclic polyisocyanates, dimers or trimers of these polyisocyanates, and adducts of these polyisocyanates and polyols such as trimethylolpropane. Any one of these may be used alone, or two or more thereof may be used in combination.

Examples of epoxy-based cross-linking agents include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, bisphenol A type epoxy resin, and N,N,N',N'-tetraglycidyl. -m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N-diglycidylaniline, N,N-diglycidyltoluidine and the like.

Examples of metal chelate-based cross-linking agents include compounds in which a polyvalent metal is covalently or coordinately bonded to an organic compound. Examples of polyvalent metals include aluminum, nickel, chromium, copper, iron, tin, titanium, zinc, cobalt, manganese, and zirconium. Examples of the organic compound include organic compounds having an oxygen atom, such as ketone compounds such as acetylacetone, alkyl esters, alcohol compounds, carboxylic acid compounds, and ether compounds.

The photocurable cross-linking agent is a compound that undergoes a cross-linking reaction by the action of a photopolymerization initiator or the like when irradiated with an active energy ray such as ultraviolet rays.
Examples of this type of cross-linking agent include polymerizable polyfunctional compounds having two or more radically polymerizable groups; functional groups selected from the group consisting of isocyanate groups, epoxy groups, melamine groups, glycol groups, siloxane groups and amino groups. polyfunctional organic resins having two or more; organometallic compounds having metal complexes; and the like. Metals in the metal complex include zinc, aluminum, sodium, zirconium, calcium and the like.

Examples of the radically polymerizable group in the polymerizable polyfunctional compound include those described above, and a (meth)acryloyl group is preferred. That is, the polymerizable polyfunctional compound is preferably a polyfunctional (meth)acrylate having two or more (meth)acryloyl groups.
Examples of polyfunctional (meth)acrylates include triethylene glycol diacrylate, polyalkylene glycol diacrylate, bisphenol A-EO/PO-modified diacrylate, alkoxylated hexanediol diacrylate, polyisobutylene diacrylate, and alkoxylated trimethylolpropane. triacrylate, pentaerythritol triacrylate, alkoxylated pentaerythritol triacrylate, alkoxylated pentaerythritol tetraacrylate, alkoxylated dipentaerythritol pentaacrylate, caprolactone-modified dipentaerythritol pentaacrylate and caprolactone-modified dipentaerythritol hexaacrylate. Any one of these polyfunctional (meth)acrylates may be used alone, or two or more thereof may be used in combination.

<Reaction initiator>
The adhesive resin composition of the present invention may further contain a reaction initiator, if necessary.
The reaction initiator is a compound that generates radicals upon exposure to active energy rays (ultraviolet rays, etc.) or heating.
Examples of reaction initiators include photopolymerization initiators and thermal polymerization initiators.

Examples of the photopolymerization initiator include compounds that decompose and generate radicals by irradiation with active energy rays, and compounds that generate radicals by abstracting hydrogen derived from constituents in the formulation by irradiation with active energy rays.
The photopolymerization initiator is not particularly limited, and known photopolymerization initiators can be used as appropriate. Ethan-1-one, 1-hydroxy-cyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy -2-methyl-1-propan-1-one, 2-hydroxy-1-[4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl]-2-methyl-propane-1- one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-( 4-morpholinyl)phenyl]-1-butanone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(η5-2,4-cyclopentadiene -1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium, 1,2-octanedione 1-[4-(phenylthio)-2-(o- benzoyloxime)], ethanone 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(o-acetyloxime) and the like. Any one of these photopolymerization initiators may be used alone, or two or more thereof may be used in combination.

<Filler>
The resin composition for pressure-sensitive adhesive of the present invention may further contain a filler, if necessary.
Fillers are used, for example, to impart heat resistance, thermal conductivity, flame retardancy, electrical conductivity, and the like. Examples of fillers include metal powders such as zinc oxide powder and titanium oxide powder, carbon black such as acetylene black, inorganic fillers such as talc, glass powder, silica powder, conductive particles, and glass powder; polyethylene powder; organic fillers such as polyester powder, polyamide powder, fluororesin powder, polyvinyl chloride powder, epoxy resin powder, silicone resin powder; Any one of these fillers may be used alone, or two or more thereof may be used in combination.

<Organic solvent>
The resin composition for a pressure-sensitive adhesive of the present invention can contain an organic solvent, if necessary, in order to improve coatability, film-forming properties, and the like.
The organic solvent is not particularly limited as long as it can dissolve the copolymer (A). Examples include hydrocarbon solvents such as heptane, cyclohexane, toluene, xylene, octane, mineral spirit; ethyl acetate, n-butyl acetate. , isobutyl acetate, ethylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether acetate and other ester solvents; methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone and other ketone solvents; alcohol solvents such as isobutanol; ether solvents such as dioxane, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, and propylene glycol monopropyl ether; aromatic oils such as Swasol 310, Swasol 1000, and Swasol 1500 manufactured by Cosmo Oil system solvents and the like. Any one of these organic solvents may be used alone, or two or more thereof may be used in combination.

When the adhesive resin composition is an active energy ray-curable adhesive resin composition, it is preferable that the adhesive resin composition does not substantially contain an organic solvent. “Substantially free of organic solvent” means that the content of organic solvent is 1% by mass or less with respect to the total mass of the resin composition for pressure-sensitive adhesives. The content of the organic solvent may be 0% by mass. The content of the organic solvent can be measured by gas chromatography.

<Other additives>
The resin composition for pressure-sensitive adhesives of the present invention may optionally contain a reaction catalyst, a tackifying resin, an antioxidant, a light stabilizer, a metal deactivator, an anti-aging agent, a hygroscopic agent, an antirust agent, and a hydrous agent. Various additives such as antidegradants can be included as appropriate.
Examples of reaction catalysts include tertiary amine compounds, quaternary ammonium compounds, tin laurate compounds, and the like.
Examples of antioxidants include phenol-based, phosphorus-based, hydroxylamine-based, and sulfur-based antioxidants. Among them, phenol-based and phosphoric acid-based antioxidants are preferable because they cause little coloration of the resin after heating. These may be used alone or in combination of several types. The content of the antioxidant is preferably 0.1 to 5 parts by mass per 100 parts by mass of the copolymer (A).

The resin composition for a pressure-sensitive adhesive of the present invention can be prepared, for example, by producing the above-described copolymer (A), and if necessary, adding other components (polymerizable monofunctional compound, cross-linked agent, photopolymerization initiator, etc.).
The composition of the pressure-sensitive adhesive resin composition can be appropriately set according to the application, usage pattern, and the like of the pressure-sensitive adhesive resin composition.

<Preferred embodiment>
Preferred embodiments of the adhesive resin composition of the present invention include the following adhesive resin compositions (1) to (3).

(Resin composition for adhesive (1))
The adhesive resin composition (1) comprises a copolymer (A), a polymerizable monofunctional compound having one radically polymerizable group, a polymerizable polyfunctional compound having two or more radically polymerizable groups, and light. and a polymerization initiator.
The resin composition for pressure-sensitive adhesive (1) is active energy ray-curable.
The term "liquid" means that it exhibits a liquid state at 25°C. The viscosity of the liquid pressure-sensitive adhesive resin composition (1) measured at 25° C. with a Brookfield viscometer is preferably 1,000 to 80,000 mPa·s.
Preferably, the adhesive resin composition (1) does not substantially contain an organic solvent.
The adhesive resin composition (1) may further contain fillers, oligomer components, other additives, etc., if necessary.
The adhesive resin composition (1) can be used, for example, as LOCA.

In the adhesive resin composition (1), the content of the copolymer (A) is 10 to 80 mass with respect to the total mass (100 mass%) of the copolymer (A) and the polymerizable monofunctional compound. %, more preferably 15 to 70% by mass.

In the adhesive resin composition (1), the content of the polymerizable polyfunctional compound is 0.1 to 50 parts by mass with respect to a total of 100 parts by mass of the copolymer (A) and the polymerizable monofunctional compound. is preferred, and 0.5 to 20 parts by mass is more preferred.

In the adhesive resin composition (1), the content of the photopolymerization initiator is 0.1 with respect to a total of 100 parts by mass of the copolymer (A), the polymerizable monofunctional compound and the polymerizable polyfunctional compound. 10 parts by mass is preferable, and 0.5 to 5 parts by mass is more preferable.

(Resin composition for adhesive (2))
The adhesive resin composition (2) is a hot-melt adhesive resin composition containing the copolymer (A).
The adhesive resin composition (2) is solid at 25°C.
The adhesive resin composition (2) does not substantially contain an organic solvent.
The adhesive resin composition (2) may further contain a polymerizable monofunctional compound, a cross-linking agent, a reaction initiator, a filler, an oligomer component, other additives, and the like, if necessary.
The adhesive resin composition (2) preferably contains a cross-linking agent. Thereby, the adhesive layer or adhesive sheet formed from the resin composition for adhesive (2) can be cured (crosslinked).
The adhesive resin composition (2) is preferably an active energy ray-curable type containing a polymerizable polyfunctional compound having two or more radically polymerizable groups as a cross-linking agent and a photopolymerization initiator as a reaction initiator.
The pressure-sensitive adhesive resin composition (2) can be used as an OCA, for example, by molding into a transparent double-sided pressure-sensitive adhesive sheet, cross-linking it if necessary.

The content of the copolymer (A) in the adhesive resin composition (2) is preferably 70% by mass or more, more preferably 80% by mass or more, based on the total mass of the adhesive resin composition. % by mass.

When the resin composition for pressure-sensitive adhesive (2) contains a cross-linking agent, the content of the cross-linking agent in the resin composition for pressure-sensitive adhesive (2) can be appropriately set according to the type of the cross-linking agent. For example, when the cross-linking agent is the polymerizable polyfunctional compound, the content of the polymerizable polyfunctional compound is preferably 1 to 20 parts by weight with respect to 100 parts by weight of the copolymer (A), and 3 to 10 parts by weight. more preferred.

When the adhesive resin composition (2) contains a photopolymerization initiator, the content of the photopolymerization initiator is 100 mass in total for the copolymer (A), the polymerizable monofunctional compound and the polymerizable polyfunctional compound. 0.1 to 10 parts by mass is preferable, and 0.5 to 5 parts by mass is more preferable.

(Resin composition for adhesive (3))
The adhesive resin composition (3) is a liquid adhesive resin composition containing the copolymer (A) and an organic solvent.
The viscosity of the liquid adhesive resin composition (3) measured at 25° C. with a Brookfield viscometer is preferably 100 to 80,000 mPa·s.
The adhesive resin composition (3) may further contain a polymerizable monofunctional compound, a cross-linking agent, a reaction initiator, a filler, an oligomer component, other additives, and the like, if necessary.
The adhesive resin composition (3) preferably contains a cross-linking agent. Thereby, the adhesive layer or adhesive sheet formed from the resin composition for adhesive (3) can be cured (crosslinked).
The adhesive resin composition (3) contains a polymerizable polyfunctional compound having two or more radically polymerizable groups as a cross-linking agent, and an active energy ray-curable type or copolymer A containing a photopolymerization initiator as a reaction initiator. It is preferably a thermosetting type containing a compound that reacts with the functional group contained in the by heat.
The pressure-sensitive adhesive resin composition (3) is formed, for example, by coating the pressure-sensitive adhesive resin composition (3) on a releasable base material, drying it, and forming it into a transparent double-sided pressure-sensitive adhesive sheet, followed by heating if necessary. It can be used as a pressure-sensitive adhesive by cross-linking with UV irradiation or the like.

In the adhesive resin composition (3), the content of the copolymer (A) is preferably 70% by mass or more, more preferably 80% by mass or more, based on the solid content of the adhesive resin composition. % by mass.
The solid content of the resin composition for pressure-sensitive adhesive is the residue after removing the organic solvent from the resin composition for pressure-sensitive adhesive (3).
The solid content concentration of the adhesive resin composition can be appropriately set in consideration of the viscosity of the adhesive resin composition, and can be, for example, 10 to 90% by mass.

When the resin composition for pressure-sensitive adhesive (3) contains a cross-linking agent, the content of the cross-linking agent in the resin composition for pressure-sensitive adhesive (3) can be appropriately set according to the type of the cross-linking agent. For example, when the cross-linking agent is the polymerizable polyfunctional compound, the content of the polymerizable polyfunctional compound is preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the copolymer (A), and 0.5 to 10 parts by mass is more preferable.

When the cross-linking agent is the thermosetting type, examples of the cross-linking agent include thermosetting cross-linking agents such as isocyanate-based, epoxy-based, metal chelate-based, photo-curing, melamine-based, and aziridine-based cross-linking agents. Specific examples of the isocyanate-based, epoxy-based, and metal chelate-based cross-linking agents are the same as those described above. These cross-linking agents may be used alone or in combination of two or more.

When the crosslinking agent is the thermosetting type, the content of the thermosetting crosslinking agent is preferably 0.01 to 10 parts by weight, preferably 0.1 to 3 parts by weight, with respect to 100 parts by weight of the copolymer (A). is more preferred.

When the adhesive resin composition (3) contains a photopolymerization initiator, the content of the photopolymerization initiator is a total of 100 mass of the copolymer (A), the polymerizable monofunctional compound and the polymerizable polyfunctional compound. 0.1 to 10 parts by mass is preferable, and 0.5 to 5 parts by mass is more preferable.

<Application>
The pressure-sensitive adhesive resin composition of the present invention can be used for bonding members together.
At the time of lamination, the adhesive resin composition may be pre-formed into a sheet or applied to form an adhesive sheet and placed between the members. can be placed in
The adhesive sheet will be explained later in detail.

There are no particular restrictions on the member to be bonded using the resin composition for pressure-sensitive adhesive of the present invention. For example, it can be used for laminating window films for vehicles, buildings, etc., laminating labels for label display, and the like.
When the adhesive resin composition is transparent, it is processed into a transparent double-sided adhesive sheet, and used as an OCA for laminating various panels in displays such as liquid crystal panels, and laminating transparent plate materials such as glass. be able to. When the adhesive resin composition is transparent and liquid, it can be directly used as LOCA for such bonding.
“Transparent” means that the haze value is 10 or less when a pressure-sensitive adhesive sheet adjusted to have a thickness of 150 μm is measured by a method according to JIS K7361.
Examples of materials for the member include glass, polyethylene terephthalate, polycarbonate, polycarbonate, acrylic resin, polyvinyl alcohol, and silicone resin.

An example of a method for bonding members using the resin composition for pressure-sensitive adhesive (1) is shown below.
First, the adhesive resin composition (1) is applied to the surface of the first member to form an adhesive layer, and the second member is laminated thereon and cured as necessary. As a result, a laminate is obtained in which the first member and the second member are bonded together via the adhesive layer.

Application of the adhesive resin composition (1) can be performed using a known wet coating method such as slit coating or spin coating. Alternatively, a method may be used in which a certain amount of the adhesive resin composition is applied and the second member is adhered, thereby filling the adhesive resin composition between the first member and the second member.
The coating amount of the adhesive resin composition (1) is set according to the thickness of the adhesive layer to be formed. The thickness of the deposited layer can be appropriately set according to the application, and is not particularly limited, but is typically about 10 to 500 μm.

When the adhesive resin composition is curable, the adhesive layer (adhesive resin composition) may be cured before or after laminating the second member.
A method for curing the adhesive layer is not particularly limited. For example, when the adhesive resin composition contains a polyfunctional (meth)acrylate as a cross-linking agent and a photopolymerization initiator, the adhesive layer can be cured (photocured) by irradiation with active energy rays such as ultraviolet rays. . When the copolymer (A) has a reactive group such as a hydroxyl group and the adhesive resin composition contains a cross-linking agent (such as an isocyanate type) capable of chemically bonding with the reactive group by heating, The adhesive layer can be cured (thermally cured).

When the adhesive layer is photo-cured, the active energy ray is preferably ultraviolet rays from the viewpoint of versatility. Examples of ultraviolet light sources include xenon lamps, high-pressure mercury lamps, and metal halide lamps.

When the adhesive layer is heat-cured, a known heating means such as a hot air furnace, an electric furnace, an infrared induction heating furnace, or the like can be used as the heating means. Although the heating temperature is not particularly limited, it is preferably about 50 to 180.degree. The heating time is not particularly limited, but is preferably about 10 seconds to 60 minutes.

Before heat curing, preheating, air blowing, or the like may be performed under heating conditions in which the adhesive resin composition is not substantially cured in order to prevent defects from occurring. Preheating can be performed, for example, at a temperature of about 30 to 100° C. for about 30 seconds to 15 minutes. Air blowing can usually be carried out by blowing air heated to a temperature of about 30 to 100° C. to the coating surface for about 30 seconds to 15 minutes.
Curing may be performed after heat curing. Curing conditions can be, for example, 0 to 60° C. for about 1 to 10 days.

Since the resin composition for pressure-sensitive adhesive of the present invention contains the copolymer (A), it is possible to form a pressure-sensitive adhesive layer with excellent wet heat whitening resistance and low corrosion resistance. In addition, the adhesive layer is excellent in adhesive strength and holding power.

[Adhesive sheet]
The pressure-sensitive adhesive sheet of the present invention is a pressure-sensitive adhesive sheet (adhesive layer) using the resin composition for pressure-sensitive adhesives.
When the pressure-sensitive adhesive resin composition is curable, the pressure-sensitive adhesive sheet of the present invention may be made of the pressure-sensitive adhesive resin composition. It can be anything. From the point of handleability of the pressure-sensitive adhesive sheet, the pressure-sensitive adhesive sheet is preferably made of a cured product of the resin composition for pressure-sensitive adhesives.
The pressure-sensitive adhesive sheet of the present invention may be a transparent double-sided pressure-sensitive adhesive sheet.
The thickness of the pressure-sensitive adhesive sheet of the present invention can be appropriately set according to the application, and is not particularly limited, but is typically about 10 to 500 μm.

The pressure-sensitive adhesive sheet of the present invention may be a pressure-sensitive adhesive sheet with a release substrate, in which a release substrate is laminated on one or both sides of the pressure-sensitive adhesive sheet.

The pressure-sensitive adhesive sheet of the present invention can be produced by forming the resin composition for pressure-sensitive adhesive into a sheet and curing it as necessary.
Molding of the adhesive resin composition can be performed by a known method. For example, when the resin composition for pressure-sensitive adhesive of the present invention is solid (for example, when it is the resin composition for pressure-sensitive adhesive (2)), the resin composition for pressure-sensitive adhesive is placed between a pair of peelable substrates, A method of heating both sides of a pair of releasable substrates to melt the resin composition for pressure-sensitive adhesives and forming the same into a sheet may be used. When the pressure-sensitive adhesive resin composition of the present invention is liquid (for example, the pressure-sensitive adhesive resin composition (1) or (3)), the pressure-sensitive adhesive resin composition is applied to a release substrate, A method of drying and forming into a sheet shape, etc., may be mentioned as necessary.
Curing can be performed in the same manner as the curing of the adhesive layer.

The pressure-sensitive adhesive sheet of the present invention can be used, for example, to bond members together, like the resin composition for pressure-sensitive adhesives.
For example, an adhesive sheet is placed on the surface of the first member, the second member is laminated thereon, and cured as necessary. As a result, a laminate in which the first member and the second member are bonded via the adhesive sheet is obtained.

Since the pressure-sensitive adhesive sheet of the present invention uses the above resin composition for pressure-sensitive adhesives, it is excellent in wet heat whitening resistance and low corrosion resistance. In addition, the pressure-sensitive adhesive sheet has excellent adhesive strength and holding power.

EXAMPLES The present invention will be described in more detail below with reference to examples, but the following examples are not intended to limit the scope of the present invention. In each of the examples below, "parts" means "mass parts". Example 7 is a reference example.
The measurement methods used in each example are shown below.

<Measurement method>
(Number average molecular weight of macromonomer)
The number average molecular weight (Mn) of the macromonomer was measured using a gel permeation chromatography (GPC) device (manufactured by Tosoh Corporation, HLC-8320). Prepare a 0.2% by mass tetrahydrofuran (THF) solution of the macromonomer, and inject 10 μL of the solution into the device equipped with a Tosoh column (TSKgel SuperHZM-M×HZM-M×HZ2000, TSKguardcolumn SuperHZ-L). Flow rate: 0.35 mL/min, eluent: THF (stabilizer: butylhydroxytoluene (BHT)), column temperature: 40°C, and the number average molecular weight was calculated in terms of standard polystyrene.

(Weight average molecular weight of copolymer)
The weight average molecular weight (Mw) of the copolymer was measured using a GPC device (manufactured by Tosoh Corporation, HLC-8120). A 0.3% by mass THF solution of the copolymer was prepared, and 20 μL of the solution was injected into the apparatus equipped with a Tosoh column (TSKgel SuperHM-H×4, TSKguardcolumn SuperH-H). Measurement was performed under conditions of 6 mL/min, eluent: THF (stabilizer BHT), column temperature: 40° C., and the weight average molecular weight (Mw) was calculated in terms of standard polystyrene.

(Acid value of copolymer)
The acid value is determined by weighing 0.5 g of a sample in a beaker (A (g)), adding 50 mL of a toluene/95% ethanol solution and several drops of phenolphthalein, and titrating with a 0.5 M potassium hydroxide solution. Measured in (Titration volume = B (mL), titer of potassium hydroxide solution = f, blank measurement was performed in the same manner (titration volume C (mL) was calculated by the following formula.
Acid value (mgKOH/g) = {(BC) x 0.2 x 56.11 x f}/A/solid content)

<Synthesis Example 1>
(Production of Dispersant 1)
900 parts of deionized water, 60 parts of sodium 2-sulfoethyl methacrylate, 10 parts of potassium methacrylate and methyl methacrylate ( MMA) was added and stirred, and the temperature was raised to 50° C. while replacing the inside of the polymerization apparatus with nitrogen. 0.08 part of 2,2'-azobis(2-methylpropionamidine) dihydrochloride was added thereto as a polymerization initiator, and the temperature was further raised to 60°C. After raising the temperature, a dropping pump was used to continuously drop MMA at a rate of 0.24 parts/minute for 75 minutes. After holding the reaction solution at 60° C. for 6 hours, it was cooled to room temperature to obtain a dispersing agent 1 having a solid content of 10% by mass as a transparent aqueous solution.

(Production of chain transfer agent 1)
In a synthesizer equipped with a stirrer, under a nitrogen atmosphere, 1.00 g of cobalt(II) acetate tetrahydrate and 1.93 g of diphenylglyoxime and 80 mL of diethyl ether previously deoxygenated by nitrogen bubbling are placed. , and stirred at room temperature for 30 minutes. Then, 10 mL of boron trifluoride diethyl etherate complex was added, and the mixture was further stirred for 6 hours. The mixture was filtered and the solid was washed with diethyl ether and vacuum dried for 15 hours to obtain 2.12 g of chain transfer agent 1 as a reddish brown solid.

(Production of macromonomer)
145 parts of deionized water, 0.1 part of sodium sulfate and 0.25 part of dispersant 1 (solids content 10% by mass) are added to a polymerization apparatus equipped with a stirrer, condenser, thermometer and nitrogen gas inlet tube. were added and stirred to form a uniform aqueous solution. Next, 100 parts of MMA, 0.0035 parts of chain transfer agent 1 and Perocta (registered trademark) O (1,1,3,3-tetramethylbutyl peroxy 2-ethylhexanoate as a polymerization initiator, NOF Co., Ltd.) was added to form an aqueous suspension.
Next, the inside of the polymerization apparatus was replaced with nitrogen, the temperature was raised to 80° C., and the reaction was carried out for 3.5 hours. After that, the reaction liquid was cooled to 40° C. to obtain an aqueous suspension containing the macromonomer. This aqueous suspension was filtered through a filter, and the residue remaining on the filter was washed with deionized water, dehydrated, and dried at 40° C. for 16 hours to obtain macromonomer (a-1). The number average molecular weight of this macromonomer (a-1) was 3,000.

<Synthesis Examples 2 and 3>
In Synthesis Example 1 (production of macromonomer), 100 parts of MMA was changed to 50 parts of MMA and 50 parts of isobornyl methacrylate (IBXMA), and the amount of polymerization initiator (Perocta O) and chain transfer agent 1 charged Macromonomers (a-2) and (a-3) were obtained in the same manner as in Synthesis Example 1, except that the was changed as shown in Table 1. Table 1 shows the number average molecular weights of the macromonomers (a-2) and (a-3).

<Example 1>
40 parts of ethyl acetate, 1 part of isopropyl alcohol (IPA), 15 parts of macromonomer (a-1) were initially charged into a four-necked flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet. 3 parts of acrylamide (Aam), and 5 parts of 2-ethylhexyl acrylate (2-EHA) were added, and the external temperature was raised to 85° C. under nitrogen gas flow. After the external temperature reaches 85 ° C. and the internal temperature is stabilized, 20 parts of ethyl acetate, 77 parts of 2-EHA, and 0.13 parts of Nyper BMT-K40 (manufactured by NOF, trade name) as a polymerization initiator. A mixture (dropwise charge) consisting of was added dropwise over 4 hours. After holding for 1 hour after completion of dropping, a mixture of 0.5 parts of Perocta O and 10 parts of ethyl acetate was added over 1 hour. Then, after holding for 2 hours, 0.5 part of an antioxidant (manufactured by BASF, trade name "Irganox (registered trademark) 1010") is added, and the solid content (monomer + solvent charge) After adding ethyl acetate so that the ratio of the charged amount) was 50%, the mixture was cooled to room temperature to obtain a copolymer solution (A-1).
Table 2 shows the weight average molecular weight (Mw) of the copolymer in the copolymer solution (A-1).
A pressure-sensitive adhesive sheet was prepared from the copolymer solution (A-1) according to the following procedure, and the pressure-sensitive adhesive strength, holding power, wet heat whitening resistance and low corrosion resistance were evaluated. Table 2 shows the results.

(Preparation of adhesive sheet)
After coating the copolymer solution (A-1) on a release-treated polyethylene terephthalate (PET) film (hereinafter also referred to as a release PET film) with an applicator of 500 μm so as to have an area of 100 mm × 300 mm. After drying at 90° C. for 1.5 hours, the upper surface was covered with release PET to obtain a pressure-sensitive adhesive sheet having a configuration of release PET-adhesive layer-release PET.

(Adhesive force)
The peelable PET film on one side of the pressure-sensitive adhesive sheet was peeled off, and instead, a 38 μm PET film was adhered to obtain a laminate. Cut this laminate into strips with a width of 25 mm and a length of 300 mm, peel off the other release PET film to expose the adhesive layer, and apply a hand roller of 2 kg to a glass plate so that the bonding surface becomes 25 mm × 120 mm. and the peel strength (N/25 mm) against a glass plate was measured at a peel angle of 180° and a tensile speed of 300 mm/min according to JIS Z 0237 to determine the adhesive strength.
A: The adhesive strength is 3 N/25 mm or more.
○: Adhesive strength is 1 N/25 mm or more and less than 3 N/25 mm.
x: Adhesive strength is less than 1 N/25 mm.

(Holding force)
A peelable PET film on one side of the pressure-sensitive adhesive sheet was peeled off, and instead, a 38 μm PET film was pressure-bonded with a hand roller of 2 kg to obtain a laminate. Cut this laminate into strips of 25 mm × 100 mm, peel off the other release PET film, and use a 2 kg hand roller on a 30 mm × 100 mm stainless steel (SUS) plate to make the bonding surface 20 × 25 mm. It was pasted horizontally so that it would fit. After curing at 70°C for 30 minutes in accordance with JIS Z 0237, a weight of 0.5 kg was attached to the tip of the PET film, and the holding time was measured in a constant temperature layer at 70°C. The holding power was judged according to the following criteria.
◯: Retention time is 5 minutes or longer.
x: Retention time is less than 5 minutes.

(Wet heat whitening resistance)
After peeling off the peeling PET film on one side of the adhesive sheet and pasting the 38 μPET film, peeling off the other peeling film and pasting it onto a glass plate to create a test piece, initial haze value in accordance with JIS-K-7136. _H1 was measured. This test piece was placed in a thermo-hygrostat at 65° C. and 95 RH% for 1000 hours, and the haze value H ₂ was measured 30 minutes after taking it out, and the value of H ₂ −H ₁ was judged according to the following criteria.
A: H ₂ -H ₁ is 4.0 or less.
◯: H ₂ −H ₁ is more than 4.0 and 10.0 or less.
×: H ₂ −H ₁ is over 10.0.

(Low corrosiveness)
After peeling off one release PET film of the adhesive sheet and bonding the 38 μPET film, peel off the other release PET film and attach it to Oike Kogyo Tetrait TCF (KB300NS2-175-UH/P 50 mm × 50 mm). 50 mm×40 mm and the side without adhesive layer on both ends was 50 mm×5 mm to prepare a test piece, and the electrical resistance value Ω ₁ of both ends was measured. This test piece was placed in a constant temperature and humidity chamber at 65° C. and 95 RH% for 1000 _hours , and the electrical resistance value Ω2 was measured 30 minutes after taking it out, and the rate of change (%) was calculated by the following formula (4). .
Rate of change (%) = (Ω ₂ - Ω ₁ )/Ω ₁ × 100 (4)
This rate of change was determined according to the following criteria.
○: Change rate is 2000% or less.
x: Rate of change is over 2000%.

<Examples 2 to 11, Comparative Examples 1 to 3>
Copolymer solutions (A-2) to (A-14) were prepared in the same manner as in Example 1 except that the composition of the mixture (dropped charge) that was initially charged and dropped after heating was changed as shown in Table 2. Obtained.
Table 2 shows the weight average molecular weight (Mw) of the copolymer in the copolymer solution obtained in each example.
Further, for each copolymer solution, a pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1, and the pressure-sensitive adhesive strength, holding power, wet heat whitening resistance, and low corrosiveness were evaluated. Table 2 shows the results.

<Example 12>
After removing 80 parts of the copolymer solution (A-4) to a solid content of 99% or more, 60 parts of isodecyl acrylate (IDAA), 1 part of pentaerythritol triacrylate (PETA), and light 3 parts of a polymerization initiator (manufactured by BASF, trade name “IRGACURE (registered trademark) 184”, 1-hydroxycyclohexylphenyl ketone) was mixed to prepare a liquid adhesive resin composition.
A pressure-sensitive adhesive sheet was produced from the obtained resin composition for pressure-sensitive adhesives by the following procedure, and the pressure-sensitive adhesive sheet was evaluated in the same manner as in Example 1 for adhesive strength, holding power, wet heat whitening resistance, and low corrosiveness. . Table 3 shows the results.

(Preparation of adhesive sheet)
The adhesive resin composition is applied onto the release PET film with a 500 μm applicator, the 50 μm release PET film is attached to the adhesive surface, and the adhesive layer is cured by irradiating ultraviolet rays (UV) under the following conditions, An adhesive sheet having a configuration of release PET-adhesive layer-release PET was obtained.
"Irradiation conditions"
Light source: high-pressure mercury lamp, irradiation intensity: 200 mW/cm ² , integrated light quantity: 3000 mJ/cm ² .

<Example 13>
In the same manner as in Example 10, except that the types and amounts (parts) of the materials used were as shown in Table 3, a liquid adhesive resin composition was prepared, an adhesive sheet was produced, and adhesive strength and holding power were prepared. , wet heat whitening resistance and low corrosion resistance were evaluated. Table 3 shows the results.

<Example 14>
After removing 200 parts of the copolymer solution (A-4) to a solid content of 99% or more, 5 parts of PETA and a photopolymerization initiator (manufactured by BASF, trade name “IRGACURE 184”, 1-hydroxycyclohexyl 0.5 parts of phenyl ketone) to prepare a resin composition for pressure-sensitive adhesives.
A pressure-sensitive adhesive sheet was produced from the obtained resin composition for pressure-sensitive adhesives by the following procedure, and the pressure-sensitive adhesive sheet was evaluated in the same manner as in Example 1 for adhesive strength, holding power, wet heat whitening resistance, and low corrosiveness. . Table 3 shows the results.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive resin composition is sandwiched between a pair of release PET films, a pressure-sensitive adhesive layer having a thickness of 150 μm is formed by hot pressing at 100° C., and ultraviolet rays (UV) are irradiated under the following conditions to cure the pressure-sensitive adhesive layer. An adhesive sheet having a configuration of release PET-adhesive layer-release PET was obtained.
"Irradiation conditions"
Light source: high-pressure mercury lamp, irradiation intensity: 200 mW/cm ² , integrated light quantity: 3000 mJ/cm ² .

<Example 15>
In the same manner as in Example 12, except that the types and amounts (parts) of the materials used were as shown in Table 3, a resin composition for a pressure-sensitive adhesive was prepared, a pressure-sensitive adhesive sheet was produced, and adhesive strength, holding power, and moisture resistance were obtained. Thermal whitening and low corrosiveness were evaluated. Table 3 shows the results.

<Example 16>
0.5 part of PIC was mixed with 200 parts of the copolymer solution (A-6) to prepare a resin composition for adhesive. A pressure-sensitive adhesive sheet was produced from the obtained resin composition for pressure-sensitive adhesives by the following procedure, and the pressure-sensitive adhesive sheet was evaluated in the same manner as in Example 1 for adhesive strength, holding power, wet heat whitening resistance, and low corrosiveness. . Table 3 shows the results.
(Preparation of adhesive sheet)
The adhesive resin composition was applied onto the release PET film with a 500 μm applicator and heated at 120° C. for 1 hour to cure the adhesive layer. A pressure-sensitive adhesive sheet having a structure of pressure-sensitive adhesive layer-released PET was obtained.

<Example 17>
1.0 part of Al(acac) ₃ was mixed with 200 parts of the copolymer solution (A-6) to prepare a resin composition for an adhesive. About the obtained resin composition for adhesives, similarly to Example 14, adhesive strength, holding power, wet heat whitening resistance, and low corrosiveness were evaluated. Table 3 shows the results.

Abbreviations in the table have the following meanings.
MMA: methyl methacrylate.
IBXMA: isobornyl methacrylate.
Aam: acrylamide.
DMAAm: N,N-dimethylacrylamide.
ACMO: acryloylmorpholine.
HEAA: hydroxyethyl acrylamide.
2-EHA: 2-ethylhexyl acrylate.
LA: Lauryl acrylate.
AA: acrylic acid.
2-HEA: 2-hydroxyethyl acrylate.
IPA: isopropyl alcohol.
BMTK40: Niper BMT-K40 (manufactured by NOF Corporation, trade name).
IDAA: isodecyl acrylate.
PETA: NK Ester TMM-3L (manufactured by Shin-Nakamura Chemical).
UV3000B: Urethane acrylate (manufactured by Nippon Synthetic Chemical Co., Ltd., trade name).
BP: Benzophenone.
Irg184: IRGACURE184 (manufactured by BASF, trade name).
PIC: Polyisocyanate ("Coronate L", manufactured by Tosoh Corporation, trade name).
Al(acac) ₃ : aluminum trisacetylacetonate.

The adhesive layers of Examples 1 to 11 were excellent in adhesive strength, holding power, wet heat whitening resistance, and low corrosion resistance. The crosslinked adhesive layers of Examples 12 to 17 were also excellent in adhesive strength, holding power, wet heat whitening resistance, and low corrosion resistance.
The adhesive layer of Comparative Example 1 using a copolymer having a structural unit having a carboxyl group and not having a structural unit having an amide bond exhibited corrosiveness.
The pressure-sensitive adhesive layer of Comparative Example 2, which used a copolymer having neither a structural unit having a carboxyl group nor a structural unit having an amide bond, had low corrosiveness, but was inferior in resistance to wet heat whitening. The adhesive layer of Comparative Example 3 was inferior in holding power and wet heat whitening resistance.

ADVANTAGE OF THE INVENTION According to this invention, the resin composition for adhesives which can form the adhesion layer excellent in wet heat whitening resistance and low corrosiveness can be provided.

Claims (8)

A (meth)acrylic copolymer (meth)acrylic copolymer ( A) (excluding those having a weight average molecular weight of 1,000,000 or more and 3,500,000 or less),
The macromonomer (a) has a number average molecular weight of 1000 to 6000,
The (meth)acrylic copolymer (A) has an amide bond, and the content of structural units derived from the amide bond-containing monomer in the (meth)acrylic copolymer (A) is 0.1% by mass or more and less than 10% by mass with respect to the total mass of all structural units constituting the (meth)acrylic copolymer (A),
A resin composition for a pressure-sensitive adhesive, wherein the (meth)acrylic copolymer (A) has an acid value of 3.9 mgKOH/g or less.

(wherein R ¹ represents a hydrogen atom, a methyl group or CH ₂ OH, R ² represents OR ³ , a halogen atom, COR ⁴ , COOR ⁵ , CN, CONR ⁶ R ⁷ , NHCOR ⁸ or R ⁹ ,
R ³ to R ⁸ are each independently a hydrogen atom, an unsubstituted or substituted alkyl group, an unsubstituted or substituted alicyclic group, an unsubstituted or substituted aryl group, an unsubstituted or substituted heteroaryl group, unsubstituted or substituted non-aromatic heterocyclic group, unsubstituted or substituted aralkyl group, unsubstituted or substituted alkaryl group, represents an unsubstituted or substituted organosilyl group or an unsubstituted or substituted (poly)organosiloxane group, wherein the substituents in these groups are alkyl groups, aryl groups, heteroaryl groups, non- Aromatic heterocyclic group, aralkyl group, alkaryl group, carboxylic acid group, carboxylic acid ester group, epoxy group, hydroxy group, alkoxy group, primary amino group, secondary amino group, tertiary amino group, isocyanato group , a sulfonic acid group and a halogen atom, and R ⁹ is an unsubstituted or substituted aryl group, an unsubstituted or substituted heteroaryl group, or an unsubstituted or a non-aromatic heterocyclic group having a substituent, and the substituents in these groups are alkyl groups, aryl groups, heteroaryl groups, non-aromatic heterocyclic groups, aralkyl groups, and alkaryl groups, respectively. , carboxylic acid groups, carboxylic acid ester groups, epoxy groups, hydroxy groups, alkoxy groups, primary amino groups, secondary amino groups, tertiary amino groups, isocyanato groups, sulfonic acid groups, unsubstituted or substituted olefins It is at least one selected from the group consisting of groups and halogen atoms. ) 2. The pressure-sensitive adhesive resin composition according to claim 1, wherein the macromonomer (a) is represented by the following formula (1).

(wherein R is a hydrogen atom, an unsubstituted or substituted alkyl group, an unsubstituted or substituted alicyclic group, an unsubstituted or substituted aryl group, an unsubstituted or substituted heteroaryl group, unsubstituted or substituted non-aromatic heterocyclic group, unsubstituted or substituted aralkyl group, unsubstituted or substituted alkaryl group, unsubstituted or represents an organosilyl group having a substituent, or an unsubstituted or substituted (poly)organosiloxane group, and Q represents a main chain portion containing two or more structural units represented by the formula (a′); , Z indicates a terminal group.) 3. The pressure-sensitive adhesive resin composition according to claim 1, wherein the content of the structural unit derived from the macromonomer (a) is 3 to 60% by mass with respect to the total mass of all structural units. 4. The method according to any one of claims 1 to 3, wherein the difference between the glass transition temperature of the macromonomer (a) and the glass transition temperature of the polymer obtained by polymerizing the vinyl monomer (b) is 50° C. or more. The resin composition for pressure-sensitive adhesives described. The pressure-sensitive adhesive according to any one of claims 1 to 4, wherein the vinyl monomer (b) comprises an alkyl (meth)acrylate (y1) having an unsubstituted alkyl group having 4 to 30 carbon atoms. Resin composition. The pressure-sensitive adhesive resin composition according to any one of claims 1 to 5, wherein the (meth)acrylic copolymer (A) has a weight average molecular weight of 50,000 to 700,000. The content of the structural unit having the amide bond in the structural unit derived from the vinyl monomer (b) is 0.1 to 30 masses relative to the total mass of the structural units derived from the vinyl monomer (b). %, the resin composition for a pressure-sensitive adhesive according to any one of claims 1 to 6. A pressure-sensitive adhesive sheet using the pressure-sensitive adhesive resin composition according to any one of claims 1 to 7.