JP6996250B2 - Adhesive composition and adhesive sheet - Google Patents

Description

The present invention relates to a pressure-sensitive adhesive composition and a pressure-sensitive 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, and a transparent protective plate or the like are bonded together. There is a gap made of an air layer between each of these members, and diffused reflection of light occurs due to the difference in refractive index between the material constituting each member and air, and visibility is impaired. Therefore, in order to eliminate the air layer, each member is bonded to each other via a transparent adhesive layer. A transparent double-sided pressure-sensitive adhesive sheet called OCA (Optical Clear Adaptive) or a liquid transparent pressure-sensitive adhesive called liquid OCA (LOCA) is used to form the transparent pressure-sensitive adhesive layer.

As a pressure-sensitive adhesive composition used for OCA and the like, for example, one containing the following copolymer (1) has been proposed.
(1) A (meth) acrylic type having a mass average molecular weight of 50,000 to 1,000,000, which is obtained by polymerizing a monomer mixture containing a macromonomer having a number average molecular weight of 500 or more and less than 6000 and a vinyl monomer. Polymer (Patent Document 1).

International Publication No. 2015/080244

In the touch panel manufacturing process, durability is required after the members are bonded together. For example, in the case of LOCA, usually, LOCA is applied to one surface of a member to be bonded to form a transparent adhesive layer, and after the other member is bonded on the surface, the transparent adhesive layer is cured by ultraviolet irradiation or the like. Will be done. However, in the pressure-sensitive adhesive composition using the copolymer of the above (1), the adhesive strength tends to change depending on the environmental temperature at the time of bonding, and there is a problem in removability (reworkability) especially in a high temperature environment. .. Specifically, adhesive residue is likely to occur when the material is peeled off again in a high temperature environment. In addition, problems such as misalignment of the bonded members, dripping from the adhesive layer, protrusion of the adhesive layer, or insufficient durability of the adhesive layer after assembly may occur.

The present invention has been made in view of the above circumstances, and is a pressure-sensitive adhesive composition capable of forming an adhesive layer in which defects such as adhesive residue are unlikely to occur when re-peeling after bonding, and when re-peeling after bonding. In addition, it is an object of the present invention to provide an adhesive sheet in which defects such as adhesive residue are less likely to occur.

The present invention has the following aspects.
[1] Containing a (meth) acrylic copolymer (A) having a structural unit derived from the macromonomer (a) and a structural unit derived from the vinyl monomer (b).
The vinyl monomer (b) contains an alkyl (meth) acrylate having an alkyl group having 9 or more carbon atoms.
A pressure-sensitive adhesive composition in which the ratio of the (meth) acrylic copolymer (A) represented by _G'10 / _G'80 is 1 or more and 15 or less.
However, G'10 indicates a storage elastic modulus G'(Pa) at ₁₀ ° C., and G'80 indicates a storage elastic modulus G'(Pa) at ₈₀ ° C.
[2] The ratio _G'max / of the maximum value _G'max and the minimum value _G'min of the storage elastic modulus G'(Pa) of the (meth) acrylic copolymer (A) at 10 to 80 ° C. The pressure-sensitive adhesive composition according to claim 1, _{wherein G'min} is 1 or more and 15 or less.
[3] The ratio _G'max / of the maximum value _G'max and the minimum value _G'min of the storage elastic modulus G'(Pa) of the (meth) acrylic copolymer (A) at 80 to 150 ° C. The pressure-sensitive adhesive composition according to [1] or [2], _{wherein G'min} is 5 or more.
[4] The ratio _G'max of the maximum value _G'max and the minimum value _G'min of the storage elastic modulus G'(Pa) of the (meth) acrylic copolymer (A) at -50 to 20 ° C. / The pressure-sensitive adhesive composition according to any one of [1] to [3], _{wherein G'min} is 5 or more.
[5] When the (meth) acrylic copolymer (A) has a peak loss elastic modulus G "between -50 and 20 ° C. and the peak temperature is X ° C., the following formula (3) The pressure-sensitive adhesive composition according to any one of claims 1 to 4, wherein Y represented by) is 10 or more.
G' _(X-10) / G' _{(X + 10)} = Y ... (3)
However, G' _(X-10) indicates the storage elastic modulus G'(Pa) at (X-10) ° C, and G' _{(X + 10)} indicates the storage elastic modulus G'(Pa) at (X + 10) ° C. show.
[6] The pressure-sensitive adhesive composition according to any one of [1] to [5], wherein the macromonomer (a) has a number average molecular weight of 500 or more and 100,000 or less.
[7] The pressure-sensitive adhesive composition according to any one of [1] to [6], wherein the (meth) acrylic copolymer (A) has a weight average molecular weight of 10 to 1,000,000.
[8] The description according to any one of [1] to [7], wherein the macromonomer (a) has a radically polymerizable group and has two or more structural units represented by the following formula (a'). Adhesive composition.

（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。）
［１０］前記マクロモノマー（ａ）が、該マクロモノマー（ａ）を構成する全構成単位の合計質量（１００質量％）に対し、（メタ）アクリロイル基を有する単量体由来の構成単位を５０質量％以上含む［１］～［９］のいずれかに記載の粘着剤組成物。
［１１］前記（メタ）アクリル系共重合体（Ａ）の周波数１００ｋＨｚにおける比誘電率が３．５以下である［１］～［１０］のいずれかに記載の粘着剤組成物。
［１２］前記[１]～［１１］のいずれかに記載の粘着剤組成物を用いた粘着シート。 (In the formula, R ¹ indicates a hydrogen atom, a methyl group or CH ₂ OH, R ² indicates an 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 independently hydrogen atoms, an alkyl group having an unsubstituted or substituent, an alicyclic group having an unsubstituted or substituent, an aryl group having an unsubstituted or substituent, and an unsubstituted group. Or a heteroaryl group having a substituent, an unsubstituted or non-aromatic heterocyclic group having a substituent, an aralkyl group having an unsubstituted or substituent, an alkalil group having an unsubstituted or substituent, It represents an organosilyl group having an unsubstituted or substituent, or a (poly) organosiloxane group having an unsubstituted or substituent, and the substituents in these groups are an alkyl group, an aryl group, a heteroaryl group, and a non-substituted group, respectively. Aromatic heterocyclic group, aralkyl group, alkaline 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. , ^At least one selected from the group consisting of sulfonic acid groups and halogen atoms, where R9 is an aryl group with an unsubstituted or substituent, a heteroaryl group with an unsubstituted or substituent, or an unsubstituted or substituent. A non-aromatic heterocyclic group having a substituent is shown, and the substituents in these groups are an alkyl group, an aryl group, a heteroaryl group, a non-aromatic heterocyclic group, an aralkyl group, an alkalil group, respectively. A carboxylic acid 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 an alkyl group having an unsubstituted or substituent group. , At least one selected from the group consisting of an aryl group having an unsubstituted or substituent, an olefin group having an unsubstituted or substituent and a halogen atom. )
[9] The pressure-sensitive adhesive composition according to [8], wherein the macromonomer (a) is represented by the following formula (1).

(In the formula, R is a hydrogen atom, an alkyl group having an unsubstituted or substituent, an alicyclic group having an unsubstituted or substituent, an aryl group having an unsubstituted or substituent, an unsubstituted or substituent group. Heteroaryl group with unsubstituted or substituent, non-aromatic heterocyclic group with unsubstituted or substituent, aralkyl group having unsubstituted or substituent, alkalinel group having unsubstituted or substituent, unsubstituted or An organosilyl group having a substituent or an unsubstituted or (poly) organosiloxane group having a substituent is shown, and Q indicates a main chain portion containing two or more structural units represented by the above formula (a'). , Z indicates a terminal group.)
[10] The macromonomer (a) contains 50 structural units derived from a monomer having a (meth) acryloyl group with respect to the total mass (100% by mass) of all the structural units constituting the macromonomer (a). The pressure-sensitive adhesive composition according to any one of [1] to [9], which comprises mass% or more.
[11] The pressure-sensitive adhesive composition according to any one of [1] to [10], wherein the (meth) acrylic copolymer (A) has a relative permittivity of 3.5 or less at a frequency of 100 kHz.
[12] A pressure-sensitive adhesive sheet using the pressure-sensitive adhesive composition according to any one of the above [1] to [11].

According to the present invention, a pressure-sensitive adhesive composition capable of forming an adhesive layer in which defects such as adhesive residue are unlikely to occur when re-peeling after bonding, and defects such as adhesive residue occur when re-peeling after bonding. Can provide a difficult adhesive sheet.

The definitions of the following terms apply throughout the specification and claims.
"(Meta) acrylate" is a general term for acrylate and methacrylate.
"(Meta) acrylic acid" is a general term for acrylic acid and methacrylic acid.
The "(meth) acrylic copolymer" means a copolymer in which at least a part of the constituent units is a constituent unit derived from the (meth) acrylic monomer. The (meth) acrylic polymer may further contain a structural unit derived from a monomer (for example, styrene) other than the (meth) acrylic monomer.
The "silicone-based copolymer" means a copolymer in which at least a part of the constituent units is a constituent unit derived from a silicone-based monomer.
"(Meta) acrylic monomer" means a monomer having a (meth) acryloyl group.
"(Meta) acryloyl group" is a general term for acryloyl group and methacryloyl group.
"Vinyl monomer" means a monomer having an ethylenically unsaturated bond (polymerizable carbon-carbon double bond).
"~" Indicating a numerical range means that the numerical values described before and after the numerical range are included as the lower limit value and the upper limit value.

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

((Meta) acrylic copolymer (A))
The (meth) acrylic copolymer (A) (hereinafter, also referred to as “copolymer (A)”) is a structural unit derived from the macromonomer (a) and a structural unit derived from the vinyl monomer (b). And have.
The copolymer (A) is typically a graft copolymer in which a polymer chain derived from a macromonomer (a) and a polymer chain composed of a structural unit derived from a vinyl monomer (b) are bonded. Alternatively, it has a block copolymer structure.

<Constituent unit derived from 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. It has an addition-reactive functional group such as 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 in detail later. The two or more structural units of the macromonomer (a) may be the same or different.

When the macromonomer (a) has the radically polymerizable group, the macromonomer (a) and the vinyl monomer (b) can be copolymerized by radical polymerization to obtain the copolymer (A).
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 the structural unit 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 the functional group include the following combinations.
A combination of a hydroxyl group and a carboxyl group or an acid anhydride group.
A combination of an isocyanate group and a hydroxyl group or a thiol group or a carboxyl group.
A combination of epoxy and amino groups.
Combination of carboxyl group and epoxy group or 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 one is preferable. Even when the macromonomer (a) has the addition-reactive functional group, the macromonomer (a) may contain one or more of the addition-reactive functional groups, but it may be one. preferable.
The macromonomer (a) may have either a radically polymerizable group or the addition-reactive functional group, or may have both. When it has both a radically polymerizable group and the addition-reactive functional group, the radical-polymerizable group and the addition-reactive functional group of the macromonomer (a) may be one or two or more, respectively.

The macromonomer (a) can be copolymerized with the vinyl monomer (b), and the copolymer (A) can be a copolymer of the macromonomer (a) and the vinyl monomer (b). It preferably has a radically polymerizable group. When the copolymer (A) is a copolymer of a macromonomer (a) and a vinyl monomer (b), a macro having a functional group of the polymer composed of a structural unit derived from the vinyl monomer (b). Compared with the case where it is a reaction product with a monomer, it is excellent in that the amount of the macromonomer (a) introduced can be easily controlled and corrosion due to the residual functional group can be reduced.
As the radically polymerizable group of the macromonomer (a), a group having an ethylenically unsaturated bond is preferable. Examples of the group having an ethylenically unsaturated bond include CH ₂ = C (COOR) -CH _2- , (meth) acryloyl group, 2- (hydroxymethyl) acryloyl group, vinyl group and the like.
Here, R is a hydrogen atom, an alkyl group having an unsubstituted or substituent, an alicyclic group having an unsubstituted or substituent, an aryl group having an unsubstituted or substituent, and an unsubstituted or substituent. It has a heteroaryl group, an unsubstituted or non-aromatic heterocyclic group having a substituent, an aralkyl group having an unsubstituted or substituent, an alkalil group having an unsubstituted or substituent, an unsubstituted or substituted group. An organosilyl group having a group, or a (poly) organosiloxane group having an unsubstituted or substituent is shown.

Examples of the unsubstituted alkyl group in R include a branched or linear alkyl group having 1 to 22 carbon atoms. Specific examples of the branched or linear alkyl group having 1 to 22 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a t-butyl group, an i-butyl group and a 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 Examples thereof include a group (lauryl group), a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group (stearyl group), an i-octadecyl group, a nonadecil group, an icosyl group and a docosyl group.

The unsubstituted alicyclic group in R may be a monocyclic group or a polycyclic group, and examples thereof include an alicyclic group having 3 to 20 carbon atoms. As the alicyclic group, a saturated alicyclic group is preferable, 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. Groups, adamantyl groups and the like can be mentioned.

Examples of the unsubstituted aryl group in R include an aryl group having 6 to 18 carbon atoms. Specific examples of the aryl group having 6 to 18 carbon atoms include a phenyl group and a naphthyl group.
Examples of the unsubstituted heteroaryl group in R include a heteroaryl group having 4 to 18 carbon atoms. Specific examples of the heteroaryl group having 4 to 18 carbon atoms include a pyridyl group and a carbazolyl group.
Examples of the unsubstituted non-aromatic heterocyclic group in R include a heterocyclic group having 4 to 18 carbon atoms. Specific examples of the heterocyclic group having 4 to 18 carbon atoms include an oxygen atom-containing heterocyclic group such as a tetrahydrofuryl group, a tetrahydropyranyl group, a γ-butyrolactone group and an ε-caprolactone group, a pyrrolidinyl group and a pyrrolidone group. Examples thereof include a nitrogen atom-containing heterocyclic group and a morpholino group.
Examples of the unsubstituted aralkyl group include a benzyl group and a phenylethyl group.

Examples of the unsubstituted organosilyl group include -SiR ¹⁷ R ¹⁸ R ¹⁹ (where R ¹⁷ to R ¹⁹ are independently alkyl groups having unsubstituted or substituents, and alicyclics having unsubstituted or substituents, respectively. The formula group, or an aryl group having an unsubstituted or substituent is shown.).
Examples of the alkyl group having an unsubstituted or substituent in R ¹⁷ to R ¹⁹ include the same groups as described above, for example, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-amyl group and 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 can be mentioned. Examples of the alicyclic group having an unsubstituted or substituent include the same as described above, and examples thereof include a cyclohexyl group. Examples of the aryl group having an unsubstituted or substituent include the same as described above, and examples thereof include a phenyl group and p-methylphenyl. R ¹⁷ to R ¹⁹ may be the same or different from each other.
Examples of the unsubstituted (poly) organosiloxane group include -SiR ³⁰ R ³¹ -OR ³² and-(SiR ³³ R ³⁴ -O-) _n -R ³⁵ (where R ³⁰ to R ³⁵ are independent of each other, respectively. Examples thereof include an alkyl group having an unsubstituted or substituent, an alicyclic group having an unsubstituted or substituent, and an aryl group having an unsubstituted or substituent.).
Examples of the alkyl group, alicyclic group and aryl group having an unsubstituted or substituent in R ³⁰ to R ³⁵ include the same as described above.

Substituents in R (alkyl groups with substituents, alicyclic groups with substituents, aryl groups with substituents, heteroaryl groups with substituents, non-aromatic heterocyclic groups with substituents, substituents Examples of the alkyl group (where R is a substituent) include an aralkyl group having a group, an alkalinel group having a substituent, an organosilyl group having a substituent, and a (poly) organosiloxane group having a substituent. (Except when it is an alkyl group having), aryl group, -COOR ¹¹ , cyano group, -OR ¹² , -NR ¹³ R ¹⁴ , -CONR ¹⁵ R ¹⁶ , halogen atom, allyl group, epoxy group, siloxy group, and Included are at least one selected from the group consisting of groups exhibiting hydrophilicity or ionicity.
Here, R ¹¹ to R ¹⁶ are independently hydrogen atoms, an alkyl group having an unsubstituted or substituent, an alicyclic group having an unsubstituted or substituent, or an aryl having an unsubstituted or substituent. Show the group. Each of these groups includes the same as described above.

Examples of the alkyl group and the aryl group in the above-mentioned substituent include the same as the above-mentioned unsubstituted alkyl group and unsubstituted aryl group, respectively.
As R ¹¹ of —COOR ¹¹ in the above substituent, a hydrogen atom or an unsubstituted alkyl group is preferable. That is, —COOR ¹¹ is preferably a carboxy group or an alkoxycarbonyl group. Examples of the alkoxycarbonyl group include a methoxycarbonyl group.
As ^R12 of —OR ¹² in the above substituent, a hydrogen atom or an unsubstituted alkyl group is preferable. That is, —OR ¹² is preferably a hydroxy group or an alkoxy group. Examples of the alkoxy group include an alkoxy group having 1 to 12 carbon atoms, and specific examples thereof include a methoxy group.

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

Examples of the halogen atom in the above-mentioned substituent include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the group exhibiting hydrophilicity or ionicity in the above substituent include an alkali salt of a carboxy group, an alkali salt of a sulfoxy group, a poly (alkylene oxide) group such as a polyethylene oxide group and a polypropylene oxide group, and a quaternary ammonium base. Cationic substituents can be mentioned.

As R, an alkyl group having an unsubstituted or substituent, or an alicyclic group having an unsubstituted or substituent is preferable, and an unsubstituted alkyl group or a fat having an alkyl group as an unsubstituted or substituent is preferable. A cyclic group is more preferred.
Among the above, due to its 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 preferable, and methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, t-butyl group, cyclopropyl group, cyclobutyl group, isobornyl group and The adamantyl group is more preferred.

As the radically polymerizable group contained in the monomer (a1), a group having an ethylenically unsaturated bond is preferable as in the radical polymerizable group preferably possessed by the macromonomer (a).
As the monomer (a1), various ones can be used, and for example,
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 acid, isoamyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, ( Isononyl acrylate, (meth) decyl acrylate, (meth) isodecyl acrylate, lauryl (meth) acrylate, hexadecyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, (meth) Ph. Dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, terpene acrylate and its derivatives, hydrogenated rosin acrylate and its derivatives, docosyl (meth) acrylate Such as hydrocarbon group-containing (meth) acrylic acid ester;
2-Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, Hydroxy group-containing (meth) acrylic acid ester such as glycerol (meth) acrylate;
(Meta) Acrylic Acid, 2- (Meta) Acryloyloxyethyl Hexahydrophthalic Acid, 2- (Meta) Acryloyloxypropyl Hexahydrophthalic Acid, 2- (Meta) Acryloyloxyethylphthalic Acid, 2- (Meta) Acryloyloxy Propylphthalic acid, 2- (meth) acryloyloxyethyl maleic acid, 2- (meth) acryloyloxypropyl maleic acid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxypropyl succinic acid, crotonic acid , Fumalic acid, maleic acid, itaconic acid, citraconic acid, monomethyl maleate, monoethyl maleate, monooctyl maleate, monomethyl itaconic acid, monoethyl itaconic acid, monobutyl itaconic acid, monooctyl itaconate, monomethyl fumarate, monoethyl fumarate , Monobutyl fumarate, monooctyl fumarate, monoethyl citraconic acid and other carboxyl group-containing vinyl monomers;
A vinyl-based monomer containing an acid anhydride group 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 ester-based vinyl monomers such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate;
(Meta) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, Nt-butyl (meth) acrylamide, Nt-octyl (meth) acrylamide, N-methylol (meth) ) Acrylamide, N-isopropylacrylamide, hydroxyethyl acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, diacetone acrylamide, N, N-dimethylaminoethyl (meth) acrylamide, N, N- Vinyl-based monomers containing amide groups such as dimethylaminopropyl (meth) acrylamide, N-vinylacetamide, N, N'-methylenebis (meth) acrylamide, maleic acid amide, and maleimide;
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 ( Meta) 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-Nonandiol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, trimethylolpropanetri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, allyl ( Polyfunctional vinyl-based monomers such as acrylate, triallyl cyanurate, diallyl maleate, polypropylene glycol diallyl ether, N, N'-methylenebis (meth) acrylamide;
(Meta) Amide bond-containing vinyl monomers such as amide bond-containing cyclic vinyl monomers such as acryloylmorpholine, N-vinylpyrrolidone, vinylpyridine, vinylcarbazole, N-vinyl-ε-caprolactam, and maleimide;
Polyethylene glycol (meth) acrylate, Polyethylene glycol (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, n-butoxyethyl (meth) acrylate, isobutoxyethyl (meth) acrylate , (Meta) t-butoxyethyl acrylate, (meth) ethoxyethoxyethyl acrylate, (meth) phenoxyethyl acrylate, (meth) nonylphenoxyethyl acrylate, (meth) 3-methoxybutyl acrylate, (meth) Acetoxyethyl acrylate, "Plaxel FM" (caprolactone-added monomer manufactured by Daicel Chemical Co., Ltd., trade name), "Blemmer PME-100" (methoxypolyethylene glycol methacrylate manufactured by Nichiyu Co., Ltd. (ethylene glycol chain is 2). (Product name), "Blemmer PME-200" (Nichiyu Co., Ltd. methoxypolyethylene glycol methacrylate (those with 4 ethylene glycol chains), product name), "Blemmer PME-400" (Nichiyu (Nichiyu) Methoxypolyethylene glycol methacrylate (chain of ethylene glycol 9), trade name), "Blemmer 50 POEP-800B" (Octoxy polyethylene glycol-polyethylene glycol-methacrylate (chain of ethylene glycol) manufactured by Nichiyu Co., Ltd. (8, and the chain of propylene glycol is 6), trade name), "Blemmer 20 ANEP-600" (Nonylphenoxy (ethylene glycol-polyethylene glycol) monoacrylate manufactured by Nichiyu Co., Ltd., trade name), ""BlemmerAME-100" (manufactured by Nichiyu Co., Ltd., product name), "Blemmer AME-200" (manufactured by Nichiyu Co., Ltd., product name) and "Blemmer 50AOEP-800B" (manufactured by Nichiyu Co., Ltd., product) Name) and other glycol ester-based monomers,
3- (Meta) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropylmethyldiethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, vinyltrimethoxysilane , Monomer containing silane coupling agent 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 (Meta) acrylate, tri-n-octylsilyl (meth) acrylate, tri-n-dodecylsilyl (meth) acrylate, triphenylsilyl (meth) acrylate, tri-p-methylphenylsilyl (meth) acrylate, tribenzylsilyl (Meta) acrylate, triisopropylsilyl (meth) acrylate, triisobutylsilyl (meth) acrylate, tri-s-butylsilyl (meth) acrylate, tri-2-methylisopropylsilyl (meth) acrylate, tri-t-butylsilyl (meth) ) Acrylic, 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, triisopropylsilylmethylmalate, triisopropylsilylamylmalate, tri-n-butylsilyl-n-butylmalate , T-Butyldiphenylsilylmethylmalate, t-butyldiphenylsilyl-n-butylmalate, triisopropylsilylmethylfumarate, triisopropylsilylamylfumarate, tri-n-butylsilyl-n-butylfumarate, t-butyldiphenyl Cyrilmethylfumarate, t-butyldiphenylsilyl-n-butylfumarate, Cyraplane FM-0711 (manufactured by JNC Co., Ltd., trade name), Cyraplane FM-0721 (manufactured by JNC Co., Ltd., trade name), Cyra Plain FM-0725 (manufactured by JNC Co., Ltd., product name), Silaplane TM-0701 (manufactured by JNC Co., Ltd., product name), Silaplane TM-0701T (manufactured by JNC Co., Ltd., product name), X-22 -174ASX (manufactured by Shinetsu Chemical Industry Co., Ltd., product name), X-22-174BX (manufactured by Shinetsu Chemical Industry Co., Ltd., product name), KF-2012 (manufactured by Shinetsu Chemical Industry Co., Ltd., product name), X -22-2426 (Shinetsu) Organosilyl group-containing monomers other than silane coupling agent-containing monomers such as Gakuko Kogyo Co., Ltd. (trade name), X-22-2404 (Shin-Etsu Chemical Co., Ltd., trade name);
Halogenated olefins such as vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, chlorotrifluoroethylene;
(Meta) Isocyanato group-containing monomer 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 ( Meta) 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) acrylates (excluding halogenated olefins),
It has an acetal structure such as 1-butoxyethyl (meth) acrylate, 1- (2-ethylhexyloxy) ethyl (meth) acrylate, 1- (cyclohexyloxy) ethyl methacrylate), 2-tetrahydropyranyl (meth) acrylate. Monomer,
Examples thereof include other vinyl monomers such as 4-methacryloyloxybenzophenone, styrene, α-methylstyrene, vinyltoluene, (meth) acrylonitrile, vinyl acetate and vinyl propionate. One of these monomers may be used alone, or two or more thereof may be used in combination.
It is preferable that at least a part of the monomer (a1) is 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 "constituent unit (a')") is preferable. That is, the macromonomer (a) preferably has a radically polymerizable group and has 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、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）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アルキル基、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。）

(In the formula, R ¹ indicates a hydrogen atom, a methyl group or CH ₂ OH, R ² indicates an 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 independently hydrogen atoms, an alkyl group having an unsubstituted or substituent, an alicyclic group having an unsubstituted or substituent, an aryl group having an unsubstituted or substituent, and an unsubstituted group. Or a heteroaryl group having a substituent, an unsubstituted or non-aromatic heterocyclic group having a substituent, an aralkyl group having an unsubstituted or substituent, an alkalil group having an unsubstituted or substituent, It shows an organosilyl group having an unsubstituted or substituent and a (poly) organosiloxane group having an unsubstituted or substituent, and the substituents in these groups are an alkyl group, an aryl group, a heteroaryl group and a non-aromatic group, respectively. Group heterocyclic group, aralkyl group, alkaline group, carboxylic acid group (COOH), carboxylic acid ester group, epoxy group, hydroxy group, alkoxy group, primary amino group, secondary amino group, tertiary amino group, It is at least one selected from the group consisting of an isocyanato group, a sulfonic acid group (SO _3H ) and a halogen atom.
R ⁹ represents an aryl group having an unsubstituted or substituent, a heteroaryl group having an unsubstituted or substituent, or a non-aromatic heterocyclic group having an unsubstituted or substituent, and in these groups. The substituents are an alkyl group, an aryl group, a heteroaryl group, a non-aromatic heterocyclic group, an aralkyl group, an alkalinel group, a carboxylic acid group, a carboxylic acid ester group, an epoxy group, a hydroxy group, and an alkoxy group, respectively. A secondary amino group, a secondary amino group, a tertiary amino group, an isocyanato group, a sulfonic acid group, an alkyl group having an unsubstituted or substituent, an aryl group having an unsubstituted or substituent, an unsubstituted or substituent group. It is at least one selected from the group consisting of an olefin group and a halogen atom having. )

Unsubstituted alkyl group, unsubstituted alicyclic group, unsubstituted aryl group, unsubstituted heteroaryl group, unsubstituted non-aromatic heterocyclic group, unsubstituted aralkyl group in R ³ to R ⁸ , The unsubstituted alkaline group, the unsubstituted organosilyl group, and the unsubstituted (poly) organosiloxane group are the same as those mentioned in R above, respectively.

Substituents in R ³ to R ⁸ (alkyl group having substituent, alicyclic group having substituent, aryl group having substituent, heteroaryl group having substituent, non-aromatic heterocycle having substituent) Among the substituents in each of the formula group, the aralkyl group having a substituent, the alkalinel group having a substituent, and the organosilyl group having a substituent), an alkyl group, an aryl group, a heteroaryl group, and a non-aromatic heterocyclic group. Examples of the group, the aralkyl group and the alkaline group are the same as described above.
Examples of the carboxylic acid ester group include an alkyl group in which R ¹¹ of -COOR ¹¹ is unsubstituted or has a substituent, an alicyclic group having an unsubstituted or substituent, or an aryl having an unsubstituted or substituent. A group that is a group is mentioned.
Examples of the alkoxy group include a group in which ^R12 of —OR ¹² is an unsubstituted alkyl group.
As the secondary amino group, R ¹³ of the -NR ¹³ R ¹⁴ is a hydrogen atom, R ¹⁴ is an alkyl group having an unsubstituted or substituent, an alicyclic group having an unsubstituted or substituent, or an unsubstituted group. Or a group which is an aryl group having a substituent.
As the tertiary amino group, R ¹³ and R ¹⁴ of -NR ¹³ R ¹⁴ are an alkyl group having an unsubstituted or substituent, an alicyclic group having an unsubstituted or substituent, or an unsubstituted or unsubstituted group. Examples thereof include a group which is an aryl group having a substituent.
Examples of the alkyl group having an unsubstituted or substituent, an aryl group having an unsubstituted or substituent, and a halogen atom are the same as described above.

^Examples of the unsubstituted aryl group, the unsubstituted heteroaryl group, and the unsubstituted non-aromatic heterocyclic group in R9 are the same as described above.
Among the substituents in ^R9 (aryl groups having a substituent, a heteroaryl group having a substituent, and a substituent in each of a non-aromatic heterocyclic group having a substituent), a carboxylic acid ester group, an alkoxy group, and 1 Examples of the primary amino group, the secondary amino group, the tertiary amino group, the alkyl group having an unsubstituted or substituent, the aryl group having an unsubstituted or substituent, and the halogen atom are the same as described above. ..
Examples of the unsubstituted olefin group include an allyl group and the like.
Examples of the substituent in the olefin group having a substituent include the same as the substituent ⁱⁿ R8.

The structural unit (a') is a structural unit derived from CH ₂ = CR ¹ R ² . Specific examples of CH ₂ = CR ¹ R ² include the following.
Substituent or unsubstituted alkyl (meth) acrylates [eg, methyl (meth) acrylates, ethyl (meth) acrylates, n-propyl (meth) acrylates, i-propyl (meth) acrylates, n-butyl (meth) acrylates, 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 ( Meta) acrylate, 3-methoxybutyl (meth) acrylate, 3-methyl-3-methoxybutyl (meth) acrylate], substituted or unsubstituted aralkyl (meth) acrylate [eg, benzyl (meth) acrylate, m-methoxyphenyl] Ethyl (meth) acrylate, p-methoxyphenyl ethyl (meth) acrylate], substituted or unsubstituted aryl (meth) acrylate [eg, phenyl (meth) acrylate, m-methoxyphenyl (meth) acrylate, p-methoxyphenyl (eg) Meta) acrylate, o-methoxyphenylethyl (meth) acrylate], alicyclic (meth) acrylate [eg, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate], halogen atom-containing (meth) acrylate [eg, trifluoro Hydrophobic group-containing (meth) acrylic acid ester monomer such as ethyl (meth) acrylate, perfluorooctyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate];
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-ethylhexoxy) ethyl (meth) acrylate and other oxyethylene group-containing (meth) acrylic acid ester monomers;
Hydroxyl-containing (meth) acrylic acid ester monomers such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and glycerol (meth) acrylate;
Terminal alkoxyallylated polyethers such as methoxypolyethylene glycol allyl ether, methoxypolyethylene glycol allyl ether, butoxypolyethylene glycol allyl ether, butoxypolyethylene glycol allyl ether, methoxypolyethylene glycol-polypropylene glycol allyl ether, butoxypolyethylene glycol-polypropylene glycol allyl ether. Quantitative;
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 and (meth) acrylamide;
Dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, dimethylaminobutyl (meth) acrylate, dibutylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylamide, dimethylaminopropyl (Meta) Tertiary amino group-containing vinyl monomer such as acrylamide;
Heterocyclic basic monomers such as vinylpyrrolidone, 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 (Meta) acrylate, tri-n-octylsilyl (meth) acrylate, tri-n-dodecylsilyl (meth) acrylate, triphenylsilyl (meth) acrylate, tri-p-methylphenylsilyl (meth) acrylate, tribenzylsilyl (Meta) 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 and other organosilyl group-containing vinyl monomers;
Methacrylic acid, acrylic acid, vinyl benzoic acid, monohydroxyethyl (meth) acrylate with tetrahydrophthalate, monohydroxypropyl (meth) acrylate with tetrahydrophthalate, monohydroxybutyl (meth) acrylate with tetrahydrophthalate, monohydroxyethyl phthalate (meth) ) Acrylate, monohydroxypropyl phthalate (meth) acrylate, monohydroxyethyl succinate (meth) acrylate, monohydroxypropyl succinate (meth) acrylate, monohydroxyethyl maleate (meth) acrylate, monohydroxypropyl maleate (meth) ) Carboxy group-containing ethylenically unsaturated monomer such as acrylate;
Cyano group-containing vinyl monomers such as acrylonitrile and methacrylonitonyl;
Vinyl ether monomers such as alkyl vinyl ethers [eg, ethyl vinyl ethers, propyl vinyl ethers, butyl vinyl ethers, hexyl vinyl ethers, 2-ethylhexyl vinyl ethers, etc.], cycloalkyl vinyl ethers [eg, cyclohexyl vinyl ethers, etc.];
Vinyl ester monomers such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate;
Aromatic vinyl monomers such as styrene, vinyltoluene, α-methylstyrene;
Halogenated olefins such as vinyl chloride and vinyl fluoride; etc.

The macromonomer (a) may further have a structural unit other than the structural unit (a'). Examples of the other structural unit include a structural unit derived from a monomer that does not correspond to CH ₂ = CR ¹ R ² among the monomers mentioned as an example of the above-mentioned monomer (a1).
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 triisopropylsilylamylfumarate, tri-n-butylsilyl-n-butylfumarate, t-butyldiphenylsilylmethylfumarate, t-butyldiphenylsilyl-n-butylfumarate;
Acid anhydride group-containing vinyl monomer 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 itaconic acid, monoethyl itaconic acid, monobutyl itaconic acid, monooctyl itaconic acid, fumal Carboxy group-containing ethylenically unsaturated monomers such as monomethyl acid, monoethyl fumarate, monobutyl fumarate, monooctyl fumarate, and monoethyl citraconic acid;
Unsaturated dicarboxylic acid diester monomers such as dimethylmalate, dibutylmalate, dimethylfumarate, dibutylfumarate, dibutylitaconate, diperfluorocyclohexylfumarate;
Halogenated olefins such as vinylidene chloride, vinylidene fluoride, and 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, trimethylpropantri (meth) acrylate, pentaerythritol Polyfunctional monomers such as tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, allyl methacrylate, triallyl cyanurate, diallyl maleate, and polypropylene glycol diallyl ether.

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

As the macromonomer (a), a macromonomer having a radically polymerizable group 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以上の構成単位（ａ’）を含む主鎖部分を示し、Ｚは末端基を示す。）

(In the formula, R is a hydrogen atom, an alkyl group having an unsubstituted or substituent, an alicyclic group having an unsubstituted or substituent, an aryl group having an unsubstituted or substituent, an unsubstituted or substituent group. Heteroaryl group with unsubstituted or substituent, non-aromatic heterocyclic group with unsubstituted or substituent, aralkyl group having unsubstituted or substituent, alkalinel group having unsubstituted or substituent, unsubstituted or An organosilyl group having a substituent or an unsubstituted or (poly) organosiloxane group having a substituent is indicated, Q indicates a main chain portion containing two or more structural units (a'), and Z indicates a terminal group. show.)

In the formula (1), R is the same as R in CH ₂ = C (COOR) -CH _2- described above, and the preferred embodiment is also the same.
The two or more structural units (a') included in Q may be the same or different.
Q may be composed of only the structural unit (a'), or may further include other structural units other than the structural unit (a').
It is preferable that Q contains, as the structural unit (a'), 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 . The ratio of the structural units is preferably 50% by mass or more, more preferably 70% by mass or more, and may be 100% by mass with respect to the total mass (100% by mass) of all the structural units constituting Q.
The number of structural units constituting Q is preferably in the range where the number average molecular weight of the macromonomer (a) is 500 or more and 100,000 or less. A more preferable range of the number average molecular weight is as described later.
Examples of Z include a hydrogen atom, a group derived from a radical polymerization initiator, a radically polymerizable group, and the like, as in the case of a terminal group of a known polymer obtained by radical polymerization.

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

（式中、Ｒ及びＺはそれぞれ前記と同義であり、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へテロアリール基、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、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、ｎは２以上の自然数を示す。）

(In the formula, R and Z are synonymous with the above, R ²¹ represents a hydrogen atom or a methyl group, R ²² is an alkyl group having an unsubstituted or substituent, and an alicyclic having an unsubstituted or substituent. Formula groups, aryl groups with unsubstituted or substituents, heteroaryl groups with unsubstituted or substituents, aralkyl groups with unsubstituted or substituents, alkalinel groups with unsubstituted or substituents, non-substituted groups. An organosilyl group having a substituted or substituent or a (poly) organosiloxane group having an unsubstituted or substituent is shown, and the substituents in these groups are an alkyl group, an aryl group, a heteroaryl group and a non-aromatic group, respectively. Group heterocyclic group, aralkyl group, alkalinel 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, It is at least one selected from the group consisting of a sulfonic acid group and a halogen atom, and n represents a natural number of 2 or more.)

In the formula (2), each group in R ²² is the same as that mentioned in R ⁵ of COOR ⁵ .
n is a natural number of 2 or more. n is in the range where the number average molecular weight (Mn) of the macromonomer (a) is 500 or more and 100,000 or less. The preferred range of the number average molecular weight is as follows. The n R ^21s may be the same or different. The n R ^22s may be the same or different.

When the macromonomer (a) has the addition-reactive functional group and this macromonomer is added to the functional group of the polymer composed of the structural unit derived from the vinyl monomer (b), the macromonomer (a) is used. Is preferably one having one or more of the addition-reactive functional groups and two or more of the above-mentioned structural units (a'). As the structural unit (a'), the same one as in the case where the macromonomer (a) has a radically polymerizable group can be used.
In addition to the macromonomer (a), a compound having a functional group can be added to the functional group of a polymer composed of a structural unit derived from the vinyl monomer (b). Examples of compounds having a functional group are 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., product name), X-22-170DX (manufactured by Shin-Etsu Chemical Co., Ltd., product name), X-22-176DX (manufactured by Shin-Etsu Chemical Co., Ltd., product name), Examples thereof 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 composition of the monomers constituting the macromonomer (a) is typically different from the composition of the vinyl monomer (b). The composition indicates the type and content ratio of the monomer.
The vinyl monomer (b) contains a monomer (b1) described later. Therefore, the monomer constituting the macromonomer (a) does not contain the monomer (b1), or even if it contains the monomer (b1), the content ratio is different.
The ratio of the structural units derived from the monomer (b1) to the total of all the structural units constituting the macromonomer (a) is preferably 0 to 20% by mass.

Since _G'10 / _G'80 , which will be described later, is 15 or less, a polymer obtained by polymerizing only the macromonomer (a) and the vinyl monomer (b) (hereinafter, "polymer (B)"". Also referred to as), typically there is a difference in polarity. The larger the difference in polarity between the polymer (B) and the macromonomer (a), the smaller the _{G'max / G'min at G'10 / G'80} or _10-80 ° C., which tends to approach 1. There is. Therefore, the composition of the monomer constituting the macromonomer (a) is typically a composition that causes a difference in polarity with the polymer (B).

The macromonomer (a) preferably contains a structural unit derived from a monomer having a higher polarity than the monomer (b1). As a result, the difference in polarity between the polymer obtained by polymerizing only the monomer (b1) and the macromonomer (a) becomes large, and at G'10 / G'80 and ₁₀ to ₈₀ ° C. described later. _G'max / _G'min becomes smaller.
As a monomer having a higher polarity than the monomer (b1), a highly polar functional group such as a (meth) acrylic acid ester having less than 9 carbon atoms, a carboxy group, a hydroxyl group, an amino group, or an amide group can be used. Examples thereof include vinyl monomers having, and methyl methacrylate is preferable from the viewpoint of the yield at the time of polymerization and the ease of adjusting the adhesive strength.
The ratio of the constituent units derived from methyl methacrylate to the total of all the constituent units constituting the macromonomer (a) is preferably 50% by mass or more, more preferably 75% by mass or more, and may be 100% by mass.

The number average molecular weight (Mn) of the macromonomer (a) is preferably 500 or more and 100,000 or less, more preferably 800 to 30,000, further preferably 900 to 10000, and particularly preferably 1000 to 5500. When the number average molecular weight of the macromonomer (a) is at least the lower limit of the above range, the durability of the adhesive layer is more excellent. When the number average molecular weight of the macromonomer (a) is not more than the upper limit of the above range, the compatibility with other components and the hot melt processability when prepared as a formulation for a pressure-sensitive adhesive are more excellent.
The number average molecular weight of the macromonomer (a) is measured by gel filtration 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 Tga is at least the lower limit of the above range, the durability as an adhesive layer is more excellent. When Tga is not more than the upper limit of the above range, the workability is more excellent.
Tga can be measured with a differential scanning calorimetry (DSC).
Tga can be adjusted by the composition of the monomer forming the macromonomer (a) and the like.

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

Examples of the method for producing the macromonomer (a) using the cobalt chain transfer agent include a bulk polymerization method, a solution polymerization method, and an aqueous dispersion polymerization method such as a suspension polymerization method and an emulsion polymerization method. The aqueous dispersion polymerization method is preferable, and the suspension polymerization method is more preferable, because the recovery step is simple.
As a method for chemically bonding a radically polymerizable group to a polymer, for example, it is produced by replacing the halogen group of the polymer having a halogen group with a compound having a radically polymerizable carbon-carbon double bond. Method, method of reacting a vinyl-based monomer having an acid group with a vinyl-based polymer having an epoxy group, a method of reacting a vinyl-based polymer having an epoxy group with a vinyl-based polymer having an acid group, Examples thereof include a method of reacting a vinyl-based polymer having a hydroxyl group with a diisocyanate compound to obtain a vinyl-based polymer having an isocyanate group, and reacting the vinyl-based polymer with a vinyl-based monomer having a hydroxyl group. , It may be manufactured by any method.
The number average molecular weight of the macromonomer (a) can be adjusted with a polymerization initiator, a chain transfer agent, or the like.

As a method for producing a macromonomer (a) having a 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 vinyl-based single amount having the functional group is used. A method for copolymerizing a body, a method using a chain transfer agent such as mercaptoethanol, mercaptoacetic acid, or 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 (2 hydroxyethyl) 2 imidazoline 2 yl] propane], etc. Examples thereof include a method using an initiator capable of introducing the functional group of.

<Constituent unit derived from vinyl monomer (b)>
The vinyl monomer (b) is a monomer having an ethylenically unsaturated bond and not a macromonomer (a).
The vinyl monomer (b) contains at least an alkyl (meth) acrylate having an alkyl group having 9 or more carbon atoms (hereinafter, also referred to as “monomer (b1)”).
The monomer (b1) has a low polarity because the alkyl group has a large number of carbon atoms. When the vinyl monomer (b) contains the monomer (b1), the difference in polarity between the polymer (B) and the macromonomer (a) becomes large, and _G'10 / _G'80 , which will be described later, becomes large. _{And G'max} / _G'min at 10-80 ° C becomes smaller. Further, as the number of carbon atoms in the alkyl group of the monomer (b1) increases, _G'10 / _G'80 and _G'max / _G'min tend to be smaller.
Further, when the copolymer (A) is used in a pressure-sensitive adhesive composition containing a polymerizable monofunctional compound such as the pressure-sensitive adhesive composition (1) described later, the vinyl monomer (b) is the monomer (b1). ) Is included, the compatibility between the copolymer (A) and the polymerizable monofunctional compound is more excellent. That is, as the polymerizable monofunctional compound, which will be described in detail later, a polymerizable monofunctional compound having a hydrocarbon group having 8 or more carbon atoms is often used. Since the monomer (b1) has an alkyl group having 9 or more carbon atoms, the copolymer (A) contains a structural unit derived from the monomer (b1), so that the compatibility is enhanced. 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 composition is further enhanced, and optical transparency such as OCA and LOCA is required. Useful in applications.

Specific examples of the monomer (b1) include nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, and (meth). Examples thereof include hexadecyl acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, icosyl (meth) acrylate, and behenyl (meth) acrylate.
The number of carbon atoms of the alkyl group contained in the monomer (b1) is preferably 9 to 30, more preferably 10 to 20, and particularly preferably 12 to 18.

The ratio of the monomer (b1) to the total amount of the vinyl monomer (b) is preferably 30% by mass or more, more preferably 40% by mass or more, further preferably 60% by mass or more, and particularly preferably 80% by mass or more. , 100% by mass. The greater the proportion of the monomer (b1) in the vinyl monomer (b), the greater the difference in polarity between the polymer (B) and the macromonomer (a), resulting in _G'10 / _G'80 and _G'max / _G'min at 10-80 ° C becomes smaller.

If necessary, the vinyl monomer (b) may further contain other vinyl monomers other than the monomer (b1) in addition to the monomer (b1). The other vinyl monomer can be appropriately selected from the monomers for obtaining the macromonomer (a) mentioned above.
For example, when the macromonomer (a) is added to the polymer composed of the vinyl monomer (b), the vinyl monomer has a functional group capable of reacting with the functional group of the macromonomer (a) as another vinyl monomer. It is suitable to include a monomer.
From the viewpoint of flexibility as a pressure-sensitive adhesive, ethyl (meth) acrylate can be contained as another vinyl monomer.
Other preferred vinyl monomers include (meth) acrylic acid, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, methyl (meth) acrylate, styrene, isobornyl (meth) acrylate, (. Examples thereof include cyclohexyl (meth) acrylate, benzyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, acrylamide, methacrylamide, and (meth) acryloylmorpholine.
From the viewpoint of increasing the difference in polarity between the polymer (B) and the macromonomer (a), the proportion of the vinyl monomer having a highly polar functional group such as a carboxy group, a hydroxyl group, an amino group and an amide group is determined. It is preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, and may be 0% by mass with respect to the total amount of the vinyl monomer (b).

The vinyl monomer (b) preferably has a composition in which the glass transition temperature (TgB) of the polymer (B) obtained by polymerizing only the vinyl monomer (b) is −100 to 10 ° C. TgB is preferably −65 to 0 ° C., more preferably −60 to −10 ° C. When TgB is within the above range, the pressure-sensitive adhesive composition containing the copolymer (A1) has appropriate flexibility and tackiness.

TgB is the glass transition temperature of the homopolymer of the vinyl monomer when the vinyl monomer (b) is one kind, and when there are a plurality of kinds of the vinyl monomer (b), the TgB is a plurality of kinds. Vinyl monomer means a value calculated by the Fox calculation formula from the glass transition temperature and mass fraction of each homopolymer.
The Fox calculation formula is a calculated value obtained by the following formula, and is described in the Polymer Handbook [Polymer HandBook, J. Mol. It can be obtained by using the value described in Brandrup, Interscience, 1989] (Tg in the formula corresponds to TgB).
1 / (273 + Tg) = Σ (Wi / (273 + Tgi))
(In the formula, Wi indicates the mass fraction of the monomer i, and Tgi indicates 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) in that the characteristics of each of the parts composed of the macromonomer (a) portion and the vinyl monomer (b) -derived structural unit can be sufficiently expressed. Is preferable. That is, it is preferable that Tga-TgB> 0 ° C.
Tga> TgB ... (3)
More preferably, Tga-TgB> 50 ° C., and most preferably Tga-TgB> 80 ° C.

<Contents of each structural unit>
In the copolymer (A1), the content of the structural unit derived from the macromonomer (a) is preferably 7 to 60% by mass, preferably 8 to 50% by mass, based on the total mass (100% by mass) of all the structural units. More preferably, 9 to 30% 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 durability as an adhesive layer is more excellent. When the content of the structural unit derived from the macromonomer (a) is not more than the upper limit of the above range, the compatibility with other components and the hot melt processability when made into a formulation are more excellent.

The content of the structural unit derived from the vinyl monomer (b) in the copolymer (A1) is preferably 40 to 93% by mass, preferably 50 to 92% by mass, based on the total mass (100% by mass) of all the structural units. % Is more preferable, and 50 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 formulation are more excellent. When the content of the structural unit derived from the vinyl monomer (b) is not more than the upper limit of the above range, the durability as an adhesive layer is more excellent.

<Characteristics of copolymer (A)>
The copolymer (A) has a ratio represented by _G'10 / _G'80 of 1 or more and 15 or less.
However, G'10 indicates a storage elastic modulus G'(Pa) at ₁₀ ° C., and G'80 indicates a storage elastic modulus G'(Pa) at ₈₀ ° C.
The storage elastic modulus G'is measured by the method described in Examples described later.

A _G'10 / _G'80 of 1 or more and 15 or less indicates that the change in the storage elastic modulus G'is small (low temperature dependence) in the temperature range of 10 to 80 ° C.
In general, the storage elastic modulus G'of a resin (copolymer) tends to decrease as the temperature rises, and particularly when the resin does not have a crosslinked structure, the rate of decrease tends to be large. If _G'10 / _G'80 of the copolymer (A) is 15 or less, the pressure-sensitive adhesive layer is stored when the temperature of the pressure-sensitive adhesive layer containing the copolymer (A) rises or for a long period of time. The elastic modulus G'is sufficiently maintained, and the adhesive layer is not easily deformed. Therefore, problems such as adhesive residue when the adhesive layer is peeled off are unlikely to occur. In addition, since the temperature dependence of the adhesive force is small, workability in various environments is improved.
_G'10 / _G'80 is preferably 1 or more and 9 or less, more preferably 1 or more and 5 or less, and particularly preferably 1 or more and 3 or less.

The copolymer (A) has a ratio _G'max / _G'min of the maximum value _G'max and the minimum value _G'min of the storage elastic modulus G'(Pa) at 10 to 80 ° C. of 1 or more and 15 The following is preferable.
The fact that G'max / _G'min at 10 to 80 ° C is 1 or more and 15 or less means that the change in storage elastic modulus G'in the temperature range of ₁₀ to ₈₀ ° C is similar to _G'10 / G'80. Indicates less (low temperature dependence).
The _G'max / _G'min at 10 to 80 ° C. is preferably 1 or more and 9 or less, more preferably 1 or more and 5 or less, and particularly preferably 1 or more and 3 or less.
Typically, G'10 is _G'max at 10-80 ° C, G'80 is G'min at _10-80 ° C, and _G'10 / _G'80 is _{G'at 10-80} ° C. _max / _G'min .

The copolymer (A) has a ratio _G'max / _G'min of the maximum value _G'max and the minimum value _G'min of the storage elastic modulus G'(Pa) at 80 to 150 ° C. of 5 or more. It is more preferable, it is more preferably 7 or more and 5000 or less, further preferably 10 or more and 5000 or less, and particularly preferably 20 or more and 5000 or less.
When the _G'max at 80 to 150 ° C. is about the same, the lower the molecular weight of the copolymer (A) or the lower the degree of cross-linking, the lower the _G'min and the _G'max / _G'min . It tends to grow. When _G'max / _G'min at 80 to 150 ° C. is equal to or higher than the lower limit of the above range, the compatibility with other components when used as a formulation such as LOCA, the workability during hot melt processing, etc. are more excellent. .. When _G'max / _G'min at 80 to 150 ° C. is not more than the upper limit of the above range, the durability of the adhesive layer is more excellent.
Typically, the storage modulus G'80 at ₈₀ ° C is G'max at 80-150 ° C, the storage modulus _G'150 at ₁₅₀ ° C is _G'min at 80-150 ° C, and _G'80 . / _G'150 is _G'max / _G'min at 80-150 ° C.

The copolymer (A) has a ratio _G'max / _G'min of the maximum value _G'max and the minimum value _G'min of the storage elastic modulus G'(Pa) at −50 to 20 ° C. of 5 or more. It is preferably 5 or more and 5000 or less, more preferably 10 or more and 5000 or less, and particularly preferably 20 or more and 5000 or less.
The larger the _G'max / _G'min at −50 to 20 ° C., the greater the fluctuation (decrease) in the storage elastic modulus near 0 ° C. When _G'max / _G'min at −50 to 20 ° C. is equal to or higher than the lower limit of the above range, the followability to the substrate at the time of bonding is more excellent. When _G'max / _G'min at −50 to 20 ° C. is not more than the upper limit of the above range, the durability of the adhesive layer is more excellent.
Typically, a storage modulus G'-50 at _-50 ° C is G'max at -50-20 ° C, and a storage modulus _G'20 at ₂₀ ° C is _G'min at -50-20 ° C. , G'- ₅₀ / G'20 is _G'max / _G'min at −50 to ₂₀ ° C.
_G'max / _G'min at −50 to 20 ° C. can be adjusted by the type of the monomer forming the copolymer (A) (for example, the type of the vinyl monomer (b) described later) and the like.

The copolymer (A) has a peak loss elastic modulus G "between -50 and 20 ° C., and when the peak temperature is X ° C., Y represented by the following formula (3) is 10 or more. Is preferable.
G' _(X-10) / G' _{(X + 10)} = Y ... (3)
However, G' _(X-10) indicates the storage elastic modulus G'(Pa) at (X-10) ° C, and G' _{(X + 10)} indicates the storage elastic modulus G'(Pa) at (X + 10) ° C. show.
Having a peak of the loss elastic modulus G "in the range of -50 to 20 ° C. indicates that the glass transition temperature of the copolymer (A) is in this range. A peak of the loss elastic modulus G" is in the range of -50 to -50. When the temperature is in the range of 20 ° C. and Y is 10 or more, the adhesive strength is less affected by the working environment, which is more excellent. Y is more preferably 30 or more, and even more preferably 100 or more.

The weight average molecular weight (Mw) of the copolymer (A) is preferably 10 to 1,000,000, more preferably 30,000 to 1,000,000, still more preferably 50,000 to 800,000, still more preferably 50,000 to 500,000, and 7 10,000 to 400,000 is particularly preferable, and 80,000 to 300,000 is the most preferable. When the weight average molecular weight of the copolymer (A) is at least the lower limit of the above range, the durability of the formed adhesive layer tends to be good. When the weight average molecular weight of the copolymer (A) is not more than the upper limit of the above range, the coatability of the pressure-sensitive adhesive composition tends to be good.

The relative permittivity of the copolymer (A) at a frequency of 100 kHz is preferably 3.5 or less, and particularly preferably 3.2 or less. The lower the relative permittivity, the smaller the _{G'max / G'min at G'10 / G'80} or _10-80 ° C. When the relative permittivity is not more than the above upper limit value, G'max / G'min at _G'10 / _G'80 or ₁₀ to ₈₀ ° C. tends to be in the range of 1 or more and 15 or less.

The copolymer (A) may have a crosslinked structure or may not have a crosslinked structure. In terms of coatability of the pressure-sensitive adhesive composition, compatibility with other components of the copolymer (A), and hot-melt processability, those having no crosslinked structure are preferable.

<Method for producing copolymer (A)>
Examples of the method for producing the copolymer (A) include the following production methods (α) and (β). However, the method for producing the copolymer (A) is not limited to these.
Production method (α): A method of copolymerizing a macromonomer (a) having a radically polymerizable group and a vinyl monomer (b) containing the monomer (b1).
Production method (β): A macromonomer (a) having the addition-reactive functional group, a structural unit derived from the monomer (b1), and a vinyl monomer having a functional group capable of reacting with the addition-reactive functional group. A method of reacting with a polymer composed of a structural unit derived from a vinyl monomer (b) containing a weight.
As a method for producing the copolymer (A), the production method (α) is preferable. That is, the copolymer (A) is preferably a copolymer of the macromonomer (a) and the vinyl monomer (b). In such a copolymer, the structural unit derived from the macromonomer (a) and the structural unit derived from the vinyl monomer (b) are randomly arranged. That is, polymer chains derived from a plurality of macromonomers (a) are bonded to the entire main chain of the copolymer (A). Such a polymer is, for example, in the case where the structural unit derived from the macromonomer (a) is bonded only to the end of the polymer chain composed of the structural unit derived from the vinyl monomer (b) (for example, the production method (β). ), The durability as an adhesive layer tends to be better than that of the copolymer ().

The composition of the monomers polymerized by the production method (α), that is, the type of the monomers to be polymerized and the content (% by mass) of each monomer with respect to the total mass of all the monomers are determined by the copolymer (A). The composition of the above, that is, the type of the structural unit derived from the monomer constituting the copolymer (A) and the content (% by mass) of each structural unit with respect to the total mass of all the structural units are the same.
For example, when the content of the constituent unit derived from the macromonomer (a) in the copolymer (A) is 7 to 60% by mass with respect to the total mass (100% by mass) of all the constituent units, all the monomers to be polymerized. The content of the macromonomer (a) with respect to the total mass of is 7 to 60% by mass.

The monomer may be polymerized 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 4 to 14 hours can be mentioned. At the time of polymerization, a chain transfer agent may be used if necessary.
As the polymerization method, for example, known polymerization methods such as a solution polymerization method, a suspension polymerization method, a bulk polymerization method, and an emulsion polymerization method can be applied. From the viewpoint of drying property and coating film performance in the film forming step, it is preferable that the pressure-sensitive adhesive composition containing the copolymer (A) does not contain water. The water content in the pressure-sensitive adhesive 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 pressure-sensitive adhesive composition can be measured by the volumetric Karl Fischer method. Further, in order to reduce the amount of water in the pressure-sensitive adhesive composition, it is preferable not to contain water in the process of producing the copolymer (A). The water content in 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 contain 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 holding the reaction temperature at a predetermined reaction temperature. The entire amount of the monomer may be charged in the polymerization vessel in advance (before the inside of the polymerization vessel is brought to a predetermined reaction temperature), or the monomer may be dropped and supplied after the inside of the polymerization vessel is brought to a predetermined reaction temperature. It may be charged in a polymerization vessel in advance and the balance may be dropped and supplied.

Known radical initiators can be used, for example, 2,2-azobisisobutyronitrile, 2,2-azobis (2,4-dimethylvaleronitrile), 2,2-azobis (2-methylbutyri). Lonitrile), benzoyl peroxide, cumenehydroperoxide, lauryl peroxide, dimethyl 2,2'-azubis (2-methylpropionate), 1,1,3,3-tetramethylbutylperoxy2-ethylhexano Examples thereof include ate, di-t-butyl peroxide, t-butyl peroki-2-ethylhexanoate and the like.
As the chain transfer agent, known ones can be used, and examples thereof include mercaptans such as n-dodecyl mercaptan, thioglycolic acid esters such as octyl thioglycolate, α-methylstyrene dimer, and tarpinolene.
Solvents in solution polymerization include, for example, acetone, toluene, xylene, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, methyl isobutyl ketone, methyl ethyl ketone, n-butyl acetate, ethyl acetate, n-propyl acetate, i-propyl acetate, ethyl. General organic solvents such as 3-ethoxypropionate and isopropyl alcohol can be used.

(Polymerizable monofunctional compound)
The pressure-sensitive adhesive composition of the present invention may 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 the same as described above, and a (meth) acryloyl group is preferable. That is, the polymerizable monofunctional compound is preferably a monofunctional (meth) acrylate having one (meth) acryloyl group.

As the polymerizable monofunctional compound, the same monomer as the monomer for obtaining the macromonomer (a) mentioned above can be used.
As the polymerizable monofunctional compound, a polymerizable monofunctional compound having a hydrocarbon group having 4 or more carbon atoms is preferable from the viewpoint of flexibility as a pressure-sensitive adhesive. Examples of the hydrocarbon group include an alkyl group, an aryl group, an aralkyl group and the like. The hydrocarbon group preferably has 8 to 30 carbon atoms.

When the pressure-sensitive adhesive composition of the present invention is a liquid pressure-sensitive adhesive composition, the polymerizable monofunctional compound preferably functions as a reactive diluent. As the polymerizable monofunctional compound that functions as a reactive diluent, a polymerizable monofunctional compound that is liquid at 25 ° C. is typically used. As such a polymerizable monofunctional compound, the same one as the monomer for obtaining the macromonomer (a) can be used. These polymerizable monofunctional compounds may be used alone even if any one of them is used. Often, two or more types may be used in combination.

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

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

(Crosslinking agent)
The pressure-sensitive adhesive composition of the present invention may further contain a cross-linking agent, if necessary. When the pressure-sensitive adhesive composition contains a cross-linking agent, the pressure-sensitive adhesive composition can be cured (cross-linked) and the cross-linking density of the pressure-sensitive adhesive layer can be increased. As a result, the strength, durability, etc. of the adhesive layer tend to be more excellent. Depending on the application, it is not necessary to include a cross-linking agent. Further, when the copolymer (A) has a self-crosslinking property, for example, when it has both a hydroxyl group and an isocyanato group, sufficient strength, durability and the like can be obtained without containing a cross-linking agent.
Examples of the cross-linking agent include isocyanate-based, epoxy-based, metal chelate-based, photo-curing-based, melamine-based, and aziridine-based. Any one of these cross-linking agents may be used alone, or two or more thereof may be used in combination.

Examples of the isocyanate-based cross-linking agent include aromatic polyisocyanates such as xylylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate, and tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and hydrogenated additives of the aromatic polyisocyanate. Examples thereof include aliphatic or alicyclic polyisocyanates of the above, dimers or trimerics of these polyisocyanates, and adducts composed 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 the epoxy-based cross-linking agent include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, bisphenol A type epoxy resin, N, N, N', N'-tetraglycidyl. Examples thereof include -m-xylene diamine, 1,3-bis (N, N-diglycidyl aminomethyl) cyclohexane, N, N-diglycidyl aniline, N, N-diglycidyl toluidin and the like.

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

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 active energy rays such as ultraviolet rays.
Examples of this type of cross-linking agent include a polymerizable polyfunctional compound having two or more radically polymerizable groups; a functional group selected from the group consisting of an isocyanate group, an epoxy group, a melamine group, a glycol group, a siloxane group and an amino group. Polyfunctional organic resin having two or more; an organic metal compound having a metal complex and the like can be mentioned. Examples of the metal 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 the same as described above, and a (meth) acryloyl group is preferable. That is, the polymerizable polyfunctional compound is preferably a polyfunctional (meth) acrylate having two or more (meth) acryloyl groups.
Examples of the polyfunctional (meth) acrylate include triethylene glycol diacrylate, polyalkylene glycol diacrylate, bisphenol A-EO / PO modified diacrylate, alkoxylated hexanediol diacrylate, polyisobutyrene acrylate, and alkoxylated trimethylolpropane. Examples thereof include 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 pressure-sensitive adhesive composition of the present invention may further contain a reaction initiator, if necessary.
Examples of the reaction initiator include a photopolymerization initiator, a thermal polymerization initiator and the like.

Examples of the photopolymerization initiator include compounds that are decomposed by irradiation with active energy rays to generate radicals, and compounds that are irradiated with active energy to extract hydrogen derived from constituents in the formulation to generate radicals.
The photopolymerization initiator is not particularly limited, and a known photopolymerization initiator can be appropriately used. For example, benzophenone, 2-methylbenzophenone, 4-methylbenzophenone, 2,2-dimethoxy-1,2-diphenyl can be used. Etan-1-one, 1-hydroxy-cyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy -2-Methyl-1-propane-1-one, 2-hydroxy-1- [4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl] -2-methyl-propane-1- On, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropane-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-pyrrole-1-yl) -phenyl) titanium, 1,2-octanedione 1- [4- (phenylthio) -2- (o-) Benzoyloxime)], etanone 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-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 pressure-sensitive adhesive composition of the present invention may further contain a filler, if necessary.
The filler is used, for example, to impart heat resistance, thermal conductivity, flame retardancy, electrical conductivity, and the like. Examples of the filler include metal powders such as zinc oxide powder and titanium oxide powder, carbon black such as acetylene black, talc, glass powder, silica powder, conductive particles, and inorganic fillers such as glass powder; polyethylene powder, Organic fillers such as polyester powder, polyamide powder, fluororesin powder, polyvinyl chloride powder, epoxy resin powder, and silicone resin powder; and the like. Any one of these fillers may be used alone, or two or more thereof may be used in combination.

(Organic solvent)
The pressure-sensitive adhesive composition of the present invention may contain an organic solvent, if necessary, in order to improve coating suitability, film-forming property and the like.
The organic solvent is not particularly limited as long as it can dissolve the copolymer (A), and is, for example, a hydrocarbon solvent such as heptane, cyclohexane, toluene, xylene, octane, mineral spirit; ethyl acetate, n-butyl acetate. , Ester solvents such as isobutyl acetate, ethylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether acetate; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone; methanol, ethanol, isopropanol, n-butanol, s-butanol, Alcohol-based solvents such as isobutanol; ether-based solvents such as dioxane, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, and propylene glycol monopropyl ether; aromatic petroleum such as Swazole 310, Swazole 1000, and Swazole 1500 manufactured by Cosmo Petroleum Co., Ltd. Examples include system solvents. Any one of these organic solvents can be used alone or in combination of two or more.

When the pressure-sensitive adhesive composition is an active energy ray-curable pressure-sensitive adhesive composition, it is preferable that the pressure-sensitive adhesive composition contains substantially no organic solvent. The fact that the organic solvent is substantially not contained indicates that the content of the organic solvent is 1% by mass or less with respect to the total mass of the pressure-sensitive adhesive composition. 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 pressure-sensitive adhesive composition of the present invention can be used as a reaction catalyst, a tackifier resin, an antioxidant, a photostabilizer, a metal deactivating agent, an antioxidant, a hygroscopic agent, a rust preventive, and an antioxidant, if necessary. Various additives such as agents can be appropriately contained.
Examples of the reaction catalyst include tertiary amine compounds, quaternary ammonium compounds, tin laurate compounds and the like.
Examples of the antioxidant include phenol-based, phosphorus-based, hydroxylamine-based, sulfur-based, and the like. Among them, phenol-based and phosphoric acid-based antioxidants are preferable because the resin is less colored 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 with respect to 100 parts by mass of the copolymer (A).

In the pressure-sensitive adhesive composition of the present invention, for example, the above-mentioned copolymer (A) is produced, and if necessary, other components (polymerizable monofunctional compound, cross-linking agent, etc.) are added to the obtained copolymer (A). It can be manufactured by blending a photopolymerization initiator, etc.).
The composition of the pressure-sensitive adhesive composition can be appropriately set according to the intended use, the mode of use, and the like of the pressure-sensitive adhesive composition.

(Preferable embodiment)
Preferred embodiments of the pressure-sensitive adhesive composition of the present invention include the following pressure-sensitive adhesive compositions (1) to (3).

<Adhesive composition (1)>
The pressure-sensitive adhesive composition (1) starts photopolymerization with the copolymer (A), a polymerizable monofunctional compound having one radically polymerizable group, and a polymerizable polyfunctional compound having two or more radically polymerizable groups. A liquid pressure-sensitive adhesive composition containing at least an agent.
The pressure-sensitive adhesive composition (1) is an active energy ray-curable type.
"Liquid" means to be liquid at 25 ° C. The viscosity of the liquid pressure-sensitive adhesive composition (1) measured by a B-type viscometer at 25 ° C. is preferably 1000 to 80,000 mPa · s.
The pressure-sensitive adhesive composition (1) preferably contains substantially no organic solvent.
The pressure-sensitive adhesive composition (1) may further contain a filler, an oligomer component, other additives and the like, if necessary.
The pressure-sensitive adhesive composition (1) can be used, for example, as LOCA.

The content of the copolymer (A) in the pressure-sensitive adhesive composition (1) is 10 to 80% by mass with respect to the total mass (100% by mass) of the copolymer (A) and the polymerizable monofunctional compound. It is preferably 15 to 70% by mass, more preferably.

The content of the polymerizable polyfunctional compound in the pressure-sensitive adhesive composition (1) is preferably 0.1 to 50 parts by mass with respect to 100 parts by mass in total of the copolymer (A) and the polymerizable monofunctional compound. , 0.5 to 20 parts by mass is more preferable.

The content of the photopolymerization initiator in the pressure-sensitive adhesive composition (1) is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass with respect to 100 parts by mass of the copolymer (A). ..

<Adhesive composition (2)>
The pressure-sensitive adhesive composition (2) is a hot-melt type pressure-sensitive adhesive composition containing the copolymer (A).
The pressure-sensitive adhesive composition (2) is in a solid state at 25 ° C.
The pressure-sensitive adhesive composition (2) is substantially free of organic solvents.
The pressure-sensitive adhesive 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 pressure-sensitive adhesive composition (2) preferably contains a cross-linking agent. Thereby, the pressure-sensitive adhesive layer or the pressure-sensitive adhesive sheet formed from the pressure-sensitive adhesive composition (2) can be cured (crosslinked).
The pressure-sensitive adhesive 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 composition (2) can be used as an OCA, for example, by molding it into a transparent double-sided pressure-sensitive adhesive sheet and cross-linking it if necessary.

The content of the copolymer (A) in the pressure-sensitive adhesive composition (2) is preferably 70% by mass or more, more preferably 80% by mass or more, and 100% by mass, based on the total mass of the pressure-sensitive adhesive composition. You may.

When the pressure-sensitive adhesive composition (2) contains a cross-linking agent, the content of the cross-linking agent in the pressure-sensitive adhesive composition (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 mass and 3 to 10 parts by mass with respect to 100 parts by mass of the copolymer (A). More preferred.

When the pressure-sensitive adhesive composition (2) contains a photopolymerization initiator, the content of the photopolymerization initiator is preferably 0.1 to 10 parts by mass, preferably 0.5 parts by mass, based on 100 parts by mass of the copolymer (A). Up to 5 parts by mass is more preferable.

<Adhesive composition (3)>
The pressure-sensitive adhesive composition (3) is a liquid pressure-sensitive adhesive composition containing the copolymer (A) and an organic solvent.
The viscosity of the liquid pressure-sensitive adhesive composition (3) measured by a B-type viscometer at 25 ° C. is preferably 100 to 80,000 mPa · s.
The pressure-sensitive adhesive 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 pressure-sensitive adhesive composition (3) preferably contains a cross-linking agent. Thereby, the pressure-sensitive adhesive layer or the pressure-sensitive adhesive sheet formed from the pressure-sensitive adhesive composition (3) can be cured (crosslinked).
The pressure-sensitive adhesive composition (3) is contained in a polymerizable polyfunctional compound having two or more radically polymerizable groups as a cross-linking agent, an active energy ray-curable type containing a photopolymerization initiator as a reaction initiator, or a copolymer A. It is preferably a thermosetting type containing a compound that reacts with the functional group by heat.
The pressure-sensitive adhesive composition (3) is formed into a transparent double-sided pressure-sensitive adhesive sheet by, for example, applying the pressure-sensitive adhesive composition (3) on a peelable base material and drying it, and then cross-linking the pressure-sensitive adhesive composition (3) as necessary. It can be used as an agent.

The content of the copolymer (A) in the pressure-sensitive adhesive composition (3) is preferably 70% by mass or more, more preferably 80% by mass or more, and 100% by mass with respect to the solid content of the pressure-sensitive adhesive composition (3). May be%.
The solid content of the pressure-sensitive adhesive composition (3) is the residue obtained by removing the organic solvent from the pressure-sensitive adhesive composition (3).
The solid content concentration of the pressure-sensitive adhesive composition (3) can be appropriately set in consideration of the viscosity of the pressure-sensitive adhesive composition (3) and the like, and can be, for example, 10 to 90% by mass.

When the pressure-sensitive adhesive composition (3) contains a cross-linking agent, the content of the cross-linking agent in the pressure-sensitive adhesive composition (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 mass, preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the copolymer (A). 10 parts by mass is more preferable.

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

When the cross-linking agent is the thermosetting type, the content of the thermosetting type cross-linking agent is preferably 0.01 to 10 parts by mass, preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the copolymer (A). Is more preferable.

When the pressure-sensitive adhesive composition (3) contains a photopolymerization initiator, the content of the photopolymerization initiator is preferably 0.1 to 10 parts by mass, preferably 0.5 parts by mass, based on 100 parts by mass of the copolymer (A). Up to 5 parts by mass is more preferable.

(Use)
The pressure-sensitive adhesive composition of the present invention can be used for bonding members to each other.
At the time of bonding, the pressure-sensitive adhesive composition may be formed into a sheet in advance or applied to form an adhesive sheet, which may be arranged between the members, or a material which is not formed into a sheet may be directly arranged between the members. You may.
The adhesive sheet will be described in detail later.

The member to be bonded using the pressure-sensitive adhesive composition of the present invention is not particularly limited. For example, it can be used for laminating window-pasting films for vehicles, buildings, etc., laminating labels in label display, and the like.
When the pressure-sensitive adhesive composition is transparent, it can be processed into a transparent double-sided pressure-sensitive adhesive sheet and used as OCA for bonding various panels in a display display such as a liquid crystal panel, bonding a transparent plate material such as glass, and the like. can. When the pressure-sensitive adhesive composition is transparent and liquid, it can be used as it is as LOCA for such bonding.
“Transparent” means that the haze value of the pressure-sensitive adhesive sheet adjusted to a thickness of 150 μm is 10 or less when measured by a method according to JIS K7361.
Examples of the material of the member include glass, polyethylene terephthalate, polycarbonate, polycarbonate, acrylic resin, polyvinyl alcohol, silicone resin and the like.

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

The pressure-sensitive adhesive composition (1) can be applied by using a known wet coating method such as slit coating and spin coating. Alternatively, a method of filling the pressure-sensitive adhesive composition (1) between the first member and the second member by applying a certain amount of the pressure-sensitive adhesive composition (1) and laminating the second member may be used.
The amount of the pressure-sensitive adhesive composition (1) applied is set according to the thickness of the pressure-sensitive adhesive layer to be formed. The thickness of the layer can be appropriately set according to the intended use, and is not particularly limited, but is typically about 10 to 500 μm.

When the pressure-sensitive adhesive composition (1) is curable, the pressure-sensitive adhesive layer (the pressure-sensitive adhesive composition (1)) may be cured before or after laminating the second member.
The method for curing the adhesive layer is not particularly limited. For example, when the pressure-sensitive adhesive composition (1) contains a polyfunctional (meth) acrylate as a cross-linking agent and a photopolymerization initiator, the pressure-sensitive adhesive layer may be cured (photo-cured) by irradiation with active energy rays such as ultraviolet rays. can. When the copolymer (A) has a reactive group such as a hydroxyl group and the pressure-sensitive adhesive composition (1) contains a cross-linking agent (isocyanate-based or the like) capable of chemically bonding to the reactive group by heat, it is heated. The adhesive layer can be cured (thermosetting).

When the adhesive layer is photocured, ultraviolet rays are preferable as the active energy rays from the viewpoint of versatility. Examples of the light source of ultraviolet rays include xenon lamps, high-pressure mercury lamps, metal halide lamps, and the like.

When the adhesive layer is thermally 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. The heating temperature is not particularly limited, but is preferably about 50 to 180 ° C. The heating time is not particularly limited, but is preferably about 10 seconds to 60 minutes.

Prior to thermosetting, in order to prevent the occurrence of defects, preheating, air blowing, or the like may be performed under heating conditions in which the pressure-sensitive adhesive composition (1) does not substantially cure. Preheating can be performed, for example, at a temperature of about 30 to 100 ° C. for about 30 seconds to 15 minutes. The air blow can usually be performed by blowing air heated to a temperature of about 30 to 100 ° C. on the painted surface for about 30 seconds to 15 minutes.
After heat curing, curing may be performed. The curing conditions can be, for example, about 1 to 10 days at 0 to 60 ° C.

(Action effect)
Since the pressure-sensitive adhesive composition of the present invention contains the copolymer (A), it is possible to form a pressure-sensitive adhesive layer in which defects such as adhesive residue are unlikely to occur when the pressure-sensitive adhesive composition is re-peeled after bonding. Further, since the adhesive layer has a small temperature dependence of the adhesive force, workability in various environments is improved.
Since the copolymer (A) is a (meth) acrylic copolymer, the formed adhesive layer is also excellent in durability and transparency. Further, since the copolymer (A) contains a structural unit derived from the macromonomer (a) and a structural unit derived from the vinyl monomer (b), the macromonomer (a) portion and the vinyl monomer (b) are contained. ) Can express the characteristics of each of the constituent units, and _G'10 / _G'80 can be adjusted to 1 or more and 15 or less by selecting each of the macromonomer (a) and vinyl monomer (b). ..

[Adhesive sheet]
The pressure-sensitive adhesive sheet of the present invention is a pressure-sensitive adhesive sheet using the pressure-sensitive adhesive composition.
When the pressure-sensitive adhesive composition is curable, the pressure-sensitive adhesive sheet of the present invention may be made of the pressure-sensitive adhesive composition or may be made of a cured product of the pressure-sensitive adhesive composition. good. From the viewpoint of handleability of the pressure-sensitive adhesive sheet, it is preferably made of a cured product of the pressure-sensitive adhesive composition.
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 intended use, 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 peelable base material in which a peelable base material is laminated on one side or both sides of the pressure-sensitive adhesive sheet.

The pressure-sensitive adhesive sheet of the present invention can be produced by molding the pressure-sensitive adhesive composition into a sheet shape and curing it as necessary.
The pressure-sensitive adhesive composition can be molded by a known method. For example, when the pressure-sensitive adhesive composition of the present invention is in a solid state (for example, when the pressure-sensitive adhesive composition (2)), the pressure-sensitive adhesive composition is arranged between a pair of peelable substrates, and a pair of peelable substrates is arranged. Examples thereof include a method of heating from both sides of the pressure-sensitive adhesive composition to melt the pressure-sensitive adhesive composition and forming the pressure-sensitive adhesive composition into a sheet. When the pressure-sensitive adhesive composition of the present invention is liquid (for example, when the pressure-sensitive adhesive composition (1) or (3)), the pressure-sensitive adhesive composition is applied to a peelable substrate and dried if necessary. A method of forming into a sheet shape and the like can be mentioned.
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 bonding members to each other, similar to the pressure-sensitive adhesive composition.
For example, an adhesive sheet is placed on the surface of the first member, and the second member is laminated on the adhesive sheet and cured as necessary. As a result, the first member and the second member are bonded together via the adhesive sheet to form a laminated body.

(Action effect)
Since the pressure-sensitive adhesive sheet of the present invention uses the pressure-sensitive adhesive composition, it is possible to form a pressure-sensitive adhesive layer in which defects such as adhesive residue are unlikely to occur when the pressure-sensitive adhesive composition is re-peeled after bonding. Further, since the adhesive layer has a small temperature dependence of the adhesive force, workability in various environments is improved.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the following Examples do not limit the scope of the present invention. In each of the following examples, "part" means "part by mass".
The measurement method used in each example is 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 (HLC-8320, manufactured by Tosoh Corporation). A 0.2 mass% tetrahydrofuran (THF) solution of macromonomer is prepared, and 10 μL of the above solution is injected into the above-mentioned device equipped with a column manufactured by Tosoh Corporation (TSKgel SuperHZM-M × HZM-M × HZ2000, TSKguardcolumn SuperHZ-L). Then, the measurement was carried out under the conditions of 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 apparatus (manufactured by Tosoh Corporation, HLC-8120). A 0.3% by mass THF solution of the copolymer was prepared, and 20 μL of the above solution was injected into the above-mentioned apparatus equipped with a column (TSKgel SuperHM-H × 4, TSKguardcumn SuperH-H) manufactured by Tosoh Corporation, and the flow rate: 0. The measurement was carried out under the conditions of 6 mL / min, eluent: THF (stabilizer BHT), and column temperature: 40 ° C., and the weight average molecular weight (Mw) was calculated in terms of standard polystyrene.

(Viscoelastic properties of copolymer)
The copolymer was subjected to dynamic viscoelasticity measurement under the following conditions using a viscoelasticity measuring device (Reosol-G5000: manufactured by UBM Co., Ltd.).
Measurement frequency: 1Hz, jig: Φ25mm parallel plate, measurement gap: 1mm, strain: 4%, measurement temperature -50 ° C to 150 ° C, temperature rise rate: 3 ° C / min.
From the measurement results, G'-50 to G'20, _G'10 to _G'80 , _G'80 to _{G'150 ,} were obtained, and from those values, _G'10 / _{G'80 , G'80} / G. The ratios of ' ₁₅₀ , _G' -50 / _G'20 , and _G'max / _G'min in each temperature range were calculated.
Further, the presence or absence of a peak of the loss elastic modulus G'of -50 ° C to 20 ° C is confirmed, and if there is a peak, the temperature (° C) at that time is set to X, and the storage elastic modulus G' ₍ X-10) ° C. _X-10) Y in the above formula (3) was determined using the values of the storage elastic modulus G' _{(X + 10)} (Pa) at (Pa) and (X + 10) ° C.

(Relative permittivity of copolymer)
The relative permittivity of the copolymer at a frequency of 100 kHz is such that the copolymer is placed between a polyethylene terephthalate (PET) film having a thickness of 125 μm and a release PET film having a thickness of 50 μm, and is manufactured by a hot press at 100 ° C. to a thickness of 150 μm. Using the test piece obtained by the film, the measurement was performed by the following procedure.
The 1451B manufactured by Agilent was connected to the IMPEDANCE ANALYZER _4294A manufactured by Agilent, and the capacitance CB of the test piece at a frequency of 100 kHz was measured. The capacitance C _C of the PET film having a thickness of 125 μm and the capacitance C _D of the peeled PET film having a thickness of 50 μm were also measured, and the capacitance C _A of the test piece was calculated from the following formula (i).
(1 / C _B ) = (1 / C _A ) + (1 / C _C ) + (1 / C _D ) ... (i)
The relative permittivity εr of the test piece was calculated from the following formula (ii), and the value was taken as the relative permittivity of the copolymer. The thickness of the test piece was measured with a micrometer.
_CA = ε ₀ × ε _r × π × (L / 2) 2 / d ・ ・ ・ (ii)
ε ₀ : Vacuum permittivity = 8.854 × ^10-12 ,
L: Diameter of measuring electrode = 38 mm,
d: Thickness of the adhesive layer.

<Synthesis example 1>
(Manufacturing of Dispersant 1)
In a polymerization apparatus equipped with a stirrer, a condenser, a thermometer and a nitrogen gas introduction tube, 900 parts of deionized water, 60 parts of 2-sulfoethyl sodium methacrylate, 10 parts of potassium methacrylate and methyl methacrylate ( Twelve parts of MMA) were added and stirred, and the temperature was raised to 50 ° C. while substituting nitrogen in the polymerization apparatus. 0.08 part of 2,2'-azobis (2-methylpropionamidine) dihydrochloride was added as a polymerization initiator, and the temperature was further raised to 60 ° C. After the temperature was raised, MMA was continuously added dropwise at a rate of 0.24 part / min for 75 minutes using a drip pump. After holding the reaction solution at 60 ° C. for 6 hours, the reaction solution was cooled to room temperature to obtain a dispersant 1 having a solid content of 10% by mass, which is a transparent aqueous solution.

(Manufacturing of chain transfer agent 1)
In a synthesizer equipped with a stirrer, 1.00 g of cobalt (II) acetate tetrahydrate, 1.93 g of diphenylglioxime, and 80 mL of diethyl ether previously deoxidized by nitrogen bubbling were placed in a nitrogen atmosphere. , Stirred at room temperature for 30 minutes. Then, 10 mL of boron trifluoride diethyl ether complex was added, and the mixture was further stirred for 6 hours. The mixture was filtered, the solid was washed with diethyl ether and vacuum dried for 15 hours to give 2.12 g of chain transfer agent 1 which is a reddish brown solid.

(Manufacturing of macromonomer)
In a polymerization apparatus equipped with a stirrer, a cooling tube, a thermometer and a nitrogen gas introduction tube, 145 parts of deionized water, 0.1 part of sodium sulfate and 0.25 of dispersant 1 (solid content 10% by mass). The parts were added and stirred to obtain a uniform aqueous solution. Next, 100 parts of MMA, 0.004 part of chain transfer agent 1, and Per Octa (registered trademark) O (1,1,3,3-tetramethylbutyl peroxy2-ethylhexanoate) as a polymerization initiator, Nippon Yushi 0.4 part of (manufactured by Co., Ltd.) was added to prepare an aqueous suspension.
Next, the inside of the polymerization apparatus was substituted with nitrogen, the temperature was raised to 80 ° C. and reacted for 3.5 hours, and the temperature was raised to 90 ° C. and held for 1 hour in order to further increase the polymerization rate. Then, the reaction solution was cooled to 40 ° C. to obtain an aqueous suspension containing a macromonomer. The aqueous suspension was filtered through a filter, the residue remaining on the filter was washed with deionized water, dehydrated and dried at 40 ° C. for 16 hours to give the macromonomer (a-1). The number average molecular weight of this macromonomer (a-1) was 3000.

<Synthesis example 2>
In Synthesis Example 1 (Production of Macromonomer), a macromonomer (a-2) was obtained in the same manner as in Synthesis Example 1 except that the amounts of the polymerization initiator and the chain transfer agent charged were as shown in Table 1. .. The number average molecular weight of this macromonomer (a-2) was 6700.

<Example 1>
(Preparation of copolymer solution)
In a four-necked flask equipped with a stirrer, thermometer, cooling tube, and nitrogen gas inlet, 40 parts of ethyl acetate and 10 parts of isopropyl alcohol (IPA) as the initial preparation solvent, and macromonomer as the initial preparation monomer ( 10 parts of a-1) and 5 parts of lauryl acrylate (LA) were added, and the outside temperature was raised to 85 ° C. under the aeration of nitrogen gas. After the outside temperature reaches 85 ° C and the inside temperature stabilizes, 20 parts of ethyl acetate, 85 parts of lauryl acrylate (LA), and 0 of the polymerization initiator Niper BMT-K40 (manufactured by NOF Corporation, trade name). The mixture consisting of .13 parts was added dropwise over 4 hours. After holding for 1 hour after the completion of the dropping, a mixture consisting of 0.5 part of Perocta O and 10 parts of ethyl acetate was added over 1 hour. Then, after holding for 2 hours, 0.5 part of the antioxidant (manufactured by BASF, trade name "Irganox (registered trademark) 1010") was added, and the monomer in the solid content ((monomer + solvent charge amount)) was added. Ethyl acetate was added so that the amount charged) was 50%, and the mixture was cooled to room temperature to obtain a copolymer solution (A-1). This copolymer solution was used as the pressure-sensitive adhesive composition of Example 1. Using the obtained pressure-sensitive adhesive composition, a pressure-sensitive adhesive sheet was prepared by the following procedure, and the pressure-sensitive adhesive strength and the holding power were evaluated. The results are shown in Table 2.

(Making an adhesive sheet)
A copolymer solution was applied onto a 38 μm-thick polyethylene terephthalate (PET) film with a 500 μm applicator and dried at 90 ° C. for 1.5 hours to form an adhesive layer. A peeling PET film having a thickness of 50 μm was attached to the surface of the pressure-sensitive adhesive layer after drying to obtain a pressure-sensitive adhesive sheet having a PET-adhesive layer-peeling PET structure. The peeled PET film means a PET film that has been peeled off.

(Evaluation of adhesive strength)
Cut the adhesive sheet into strips with a width of 25 mm and a length of 300 mm, peel off the peeling PET film to expose the adhesive layer, and use a 2 kg hand roller on a 30 mm x 100 mm stainless steel (SUS) plate to bond the surfaces. After bonding to a size of 25 mm × 100 mm and allowing to stand at 23 ° C for 5 minutes, the peel strength (N / 25 mm) against the SUS plate is 180 ° at a peeling angle and 300 mm / min at a tensile speed in accordance with JIS Z 0237. ) Was measured.
The peel strength (N / 25 mm) with respect to the SUS plate was measured in the same manner as above except that the temperature at rest was 80 ° C.
The value of E / F was calculated by assuming that the peel strength at 23 ° C. was E (N / 25 mm) and the peel strength at 80 ° C. was F (N / 25 mm). From the E / F value, the adhesive strength was determined according to the following criteria. The results are shown in Table 2.
A: E / F is 5 or less.
B: E / F is larger than 5.

(Evaluation of adhesive residue)
In the evaluation of the adhesive strength, the SUS plate after the peel strength measurement at each of 23 ° C. and 80 ° C. was visually confirmed, the presence or absence of adhesive residue was confirmed, and the evaluation was made according to the following criteria. The results are shown in Table 2.
A: No glue residue.
B: There is some adhesive residue, but there is no problem.
C: There is glue residue.

(Evaluation of holding power)
Cut the adhesive sheet into strips of 25 mm x 100 mm, peel off the peeling PET film to expose the adhesive layer, and use a 2 kg hand roller on a 30 mm x 100 mm stainless steel (SUS) plate to make the bonded surface 20 x. They were bonded horizontally so as to have a length of 25 mm. According to JIS Z 0237, after curing at 40 ° C for 30 minutes, put a 1 kg weight on the tip of the PET film and put it in a constant temperature bath at 40 ° C, and the time until the adhesive layer peels off and the weight falls (retention). Time) was measured. The holding force was determined according to the following criteria. The results are shown in Table 2.
A: Holding time is 60 minutes or more.
B: Retention time is 30 minutes or more and less than 60 minutes.
C: Retention time is less than 30 minutes.

<Examples 2 to 6, Comparative Examples 1 to 2>
The same as in Example 1 except that the types and amounts (parts) of the initial charged monomers and the monomers (dropped monomers) to be blended in the mixture to be dropped after the temperature rise were changed as shown in Table 2. , Copolymer solutions (A-2) to (A-8) were obtained, and the adhesive strength, adhesive residue, and holding power were evaluated. The results are shown in Table 2. Note that (A-8) is an example in which the macromonomer (a) is not used.

Weight average molecular weight (Mw), relative permittivity, viscoelastic property (G'- _{50, G'10 , G'20} ) of the copolymer contained in each of the copolymer solutions (A-1) to (A-8). , _G'80 , _G'150 , _G'10 / _G'80 , _G'80 / _G'150 , G'- ₅₀ / _G'20 , temperature X, Y) in the above formula (3) are shown in Table 2. .. The numerical value attached to G'indicates the measured temperature.

<Example 7>
80 parts of the copolymer solution (A-1) obtained in Example 1 was vacuum-dried at 130 ° C. for 6 hours to obtain a solid resin obtained by removing the solvent, and then 60 parts of 2-ethylhexyl acrylate (EHA) was added. , PETA (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name "NK ester TMM-3L" pentaerythritol triacrylate) and 10 parts of photopolymerization initiator (manufactured by BASF, trade name "IRGACURE (registered trademark) 184", 1-hydroxy A liquid pressure-sensitive adhesive composition was prepared by mixing with 3 parts of cyclohexylphenyl ketone). With respect to the obtained pressure-sensitive adhesive composition, test pieces were prepared according to the following procedure, and the pressure-sensitive adhesive strength, adhesive residue, and holding power were evaluated in the same manner as in Example 1. The results are shown in Table 3.

(Preparation of test piece)
The pressure-sensitive adhesive composition is applied onto a 38 μm PET film with an applicator so that the thickness of the pressure-sensitive adhesive layer is 50 μm to form a pressure-sensitive adhesive layer, and the obtained test piece is irradiated with ultraviolet rays (UV) under the following conditions. The adhesive layer was cured, and a peeling PET film having a thickness of 50 μm was attached to the surface of the adhesive layer to obtain a test piece having a PET-adhesive layer-peeling PET structure.
"Irradiation conditions"
Light source: High-pressure mercury lamp, irradiation intensity: 200 mW / cm ² , integrated light intensity: 3000 mJ / cm ² .

<Example 8>
A liquid pressure-sensitive adhesive composition was prepared in the same manner as in Example 7 except that the composition of the material used was as shown in Table 3. With respect to the obtained pressure-sensitive adhesive composition, test pieces were prepared in the same manner as in Example 7, and the pressure-sensitive adhesive strength, adhesive residue, and holding power were evaluated. The results are shown in Table 3.

<Example 9>
200 parts of the copolymer solution (A-1) obtained in Example 1 is mixed with 0.24 parts of polyisocyanate (“Coronate L”, manufactured by Tosoh Corporation, trade name) (PCI), and liquid adhesiveness is obtained. An agent composition was prepared. With respect to the obtained pressure-sensitive adhesive composition, test pieces were prepared according to the following procedure, and the pressure-sensitive adhesive strength, adhesive residue, and holding power were evaluated in the same manner as in Example 1. The results are shown in Table 4.

(Preparation of test piece)
The pressure-sensitive adhesive composition was applied onto a 38 μm PET film with a 500 μm applicator and dried at 120 ° C. for 1 hour to form a pressure-sensitive adhesive layer. After curing, a test piece having a composition of PET-adhesive layer-peeled PET was obtained.

<Example 10>
A liquid pressure-sensitive adhesive composition was prepared in the same manner as in Example 9 except that the composition of the material used was as shown in Table 4. With respect to the obtained pressure-sensitive adhesive composition, test pieces were prepared in the same manner as in Example 9, and the pressure-sensitive adhesive strength, adhesive residue, and holding power were evaluated. The results are shown in Table 4.

The meanings of the abbreviations in the table are as follows.
MMA: Methyl methacrylate.
LA: Lauryl acrylate.
IDAA: Isodecyl acrylate.
BA: n-butyl acrylate.
AA: Acrylic acid.
HEA: Hydroxyethyl acrylate.
FM-0711: Cyraplane FM-0711 (manufactured by JNC Co., Ltd., trade name), organosilyl group-containing monomer.
EHA: 2-ethylhexyl acrylate.
PETA: Pentaerythritol triacrylate (manufactured by Shin Nakamura Chemical Industry Co., Ltd., trade name "NK ester TMM-3L").
PIC: Made by Tosoh Co., Ltd., product name "Coronate L".
Irg184: Made by BASF, trade name "IRGACURE184".
IPA: Isopropyl alcohol.

In the copolymers (A-1) to (A-6), G'10 is G'max at ₁₀ to 80 ° C, G'80 is _G'min at ₁₀ to ₈₀ ° C, and _G'10 / G. _'80 was _G'max / _G'min at 10-80 ° C. Further, G'80 is _G'max at ₈₀ to ₁₅₀ ° C, G'150 is _G'min at 80 to 150 ° C, and G'80 / G'150 is _G'max / _G'min at ₈₀ to ₁₅₀ ° C. Met. Further, G'- ₅₀ is G'max at -50 to ₂₀ ° C, G'20 is _G'min at -50 to 20 ° C, and G'- ₅₀ / _G'20 is G'at -50 to ₂₀ ° C. It was _max / _G'min .

The pressure-sensitive adhesive sheet using the pressure-sensitive adhesive composition of Examples 1 to 10 containing a copolymer having a G'10 / G'80 ( _G'max / _G'min at ₁₀ to ₈₀ ° C.) of 1 or more and 15 or less is adhesive. Good results were obtained in all of the force evaluation, the adhesive residue evaluation, and the holding force evaluation.
The pressure-sensitive adhesive sheet using the pressure-sensitive adhesive composition of Comparative Example 1 containing a copolymer having a _G'10 / _G'80 of more than 15 showed adhesive residue after the pressure-sensitive adhesive strength test at 80 ° C.
The pressure-sensitive adhesive sheet using the pressure-sensitive adhesive composition of Comparative Example 2 containing a copolymer having a _G'10 / _G'80 of more than 15 and not using the macromonomer (a) was pressure-sensitive at 23 ° C. and 80 ° C. The force ratio E / F was larger than 5, and adhesive residue was also observed after the peel strength measurement at 80 ° C. It was also inferior in the holding power evaluation.

Claims (12)

It contains a (meth) acrylic copolymer (A) having a structural unit derived from the macromonomer (a) and a structural unit derived from the vinyl monomer (b).
The vinyl monomer (b) contains an alkyl (meth) acrylate having 9 or more carbon atoms in the alkyl group, and the alkyl group has 9 or more carbon atoms with respect to the total amount of the vinyl monomer (b). The proportion of alkyl (meth) acrylate is 30% by mass or more,
A pressure-sensitive adhesive composition in which the ratio of the (meth) acrylic copolymer (A) represented by _G'10 / _G'80 is 1 or more and 15 or less.
However, G'10 indicates a storage elastic modulus G'(Pa) at ₁₀ ° C., and G'80 indicates a storage elastic modulus G'(Pa) at ₈₀ ° C. Ratio _G'max / _G'min of the maximum value _G'max and the minimum value _G'min of the storage elastic modulus G'(Pa) of the (meth) acrylic copolymer (A) at 10 to 80 ° C. The pressure-sensitive adhesive composition according to claim 1, wherein is 1 or more and 15 or less. The ratio _G'max / _G'min of the maximum value _G'max and the minimum value _G'min of the storage elastic modulus G'(Pa) of the (meth) acrylic copolymer (A) at 80 to 150 ° C. The pressure-sensitive adhesive composition according to claim 1 or 2, which is 5 or more. Ratio _G'max / _G'min of the maximum value _G'max and the minimum value _G'min of the storage elastic modulus G'(Pa) of the (meth) acrylic copolymer (A) at −50 to 20 ° C. The pressure-sensitive adhesive composition according to any one of claims 1 to 3, wherein the pressure is 5 or more. When the (meth) acrylic copolymer (A) has a peak loss elastic modulus G "between -50 and 20 ° C. and the peak temperature is X ° C., it is represented by the following formula (3). The pressure-sensitive adhesive composition according to any one of claims 1 to 4, wherein the Y is 10 or more.
G' _(X-10) / G' _{(X + 10)} = Y ... (3)
However, G' _(X-10) indicates the storage elastic modulus G'(Pa) at (X-10) ° C, and G' _{(X + 10)} indicates the storage elastic modulus G'(Pa) at (X + 10) ° C. show. The pressure-sensitive adhesive composition according to any one of claims 1 to 5, wherein the macromonomer (a) has a number average molecular weight of 500 or more and 100,000 or less. The pressure-sensitive adhesive composition according to any one of claims 1 to 6, wherein the (meth) acrylic copolymer (A) has a weight average molecular weight of 10 to 1,000,000. The pressure-sensitive adhesive composition according to any one of claims 1 to 7, wherein the macromonomer (a) has a radically polymerizable group and has two or more structural units represented by the following formula (a'). ..

(In the formula, R ¹ indicates a hydrogen atom, a methyl group or CH ₂ OH, R ² indicates an 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 independently hydrogen atoms, an alkyl group having an unsubstituted or substituent, an alicyclic group having an unsubstituted or substituent, an aryl group having an unsubstituted or substituent, and an unsubstituted group. Or a heteroaryl group having a substituent, an unsubstituted or non-aromatic heterocyclic group having a substituent, an aralkyl group having an unsubstituted or substituent, an alkalil group having an unsubstituted or substituent, It represents an organosilyl group having an unsubstituted or substituent, or a (poly) organosiloxane group having an unsubstituted or substituent, and the substituents in these groups are an alkyl group, an aryl group, a heteroaryl group, and a non-substituted group, respectively. Aromatic heterocyclic group, aralkyl group, alkaline 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. , ^At least one selected from the group consisting of a sulfonic acid group and a halogen atom, where R9 is an aryl group having an unsubstituted or substituent, or a heteroaryl group having an unsubstituted or substituent, or an unsubstituted. Alternatively, a non-aromatic heterocyclic group having a substituent is shown, and the substituents in these groups are an alkyl group, an aryl group, a heteroaryl group, a non-aromatic heterocyclic group, an aralkyl group, and an alkalinel group, respectively. , Carboxylic acid group, carboxylic acid ester group, epoxy group, hydroxy group, alkoxy group, primary amino group, secondary amino group, tertiary amino group, isocyanato group, sulfonic acid group, unsubstituted or substituent alkyl It is at least one selected from the group consisting of a group, an aryl group having an unsubstituted or substituent, an olefin group having an unsubstituted or substituent and a halogen atom. ) The pressure-sensitive adhesive composition according to claim 8, wherein the macromonomer (a) is represented by the following formula (1).

(In the formula, R is a hydrogen atom, an alkyl group having an unsubstituted or substituent, an alicyclic group having an unsubstituted or substituent, an aryl group having an unsubstituted or substituent, an unsubstituted or substituent group. Heteroaryl group with unsubstituted or substituent, non-aromatic heterocyclic group with unsubstituted or substituent, aralkyl group having unsubstituted or substituent, alkalinel group having unsubstituted or substituent, unsubstituted or An organosilyl group having a substituent or an unsubstituted or (poly) organosiloxane group having a substituent is shown, and Q indicates a main chain portion containing two or more structural units represented by the above formula (a'). , Z indicates a terminal group.) The macromonomer (a) contains 50% by mass or more of the structural units derived from the monomer having a (meth) acryloyl group with respect to the total mass (100% by mass) of all the structural units constituting the macromonomer (a). The pressure-sensitive adhesive composition according to any one of claims 1 to 9, which comprises. The pressure-sensitive adhesive composition according to any one of claims 1 to 10, wherein the relative dielectric constant of the (meth) acrylic copolymer (A) at a frequency of 100 kHz is 3.5 or less. A pressure-sensitive adhesive sheet using the pressure-sensitive adhesive composition according to any one of claims 1 to 11.