TW202020088A - Adhesive composition and adhesive sheet - Google Patents

Abstract

An adhesive composition including a resin represented by Fomula (1-1) and a photopolymerization initiator is disclosed. In the formula, R¹ through R⁴ are either -H or -CH₃ . R⁵ is a C1-16 alkyl group. R⁶ is either an alicyclic hydrocarbon group or an aromatic hydrocarbon group. R⁷ is either -H, or -(CH2)_j -COOH (where j is either 1 or 2). R⁸ is a specific group.

Description

Adhesive composition and adhesive sheet

The present invention relates to an adhesive composition and an adhesive sheet. This application claims priority based on Japanese Patent Application No. 2018-164843 filed with Japan on September 3, 2018, and its contents are incorporated herein.

Conventionally, various adhesive sheets have been used in semiconductor manufacturing processes and the like. Specifically, there are protective wafers used to protect wafers in the back grinding (back grind) step of semiconductor wafers, and dicing steps used to cut the semiconductor wafer into small pieces of components. Fixing sheet, etc. These adhesive sheets are re-peelable adhesive sheets that are attached to the semiconductor wafer of the adherend and are peeled from the adherend after the specific processing steps are completed. As the adhesive composition used in the adhesive layer of the re-peelable adhesive sheet, a UV (ultraviolet) hardening resin containing an ethylenically unsaturated group in the molecule is known.

Patent Document 1 discloses a method for manufacturing an adhesive sheet, which comprises reacting a (meth)acrylic polymer having two or more hydroxyl groups in a side chain with a compound having an isocyanate group in the presence of a first catalyst to form an amine group The step of the (meth)acrylic polymer of the formate bond, and the compound of the (meth)acrylic polymer having the urethane bond and one molecule having more than two isocyanate groups in the second The step of reacting in the presence of a catalyst to form an adhesive layer, wherein the first catalyst is a complex compound of at least one metal selected from zirconium, titanium, and aluminum, and the second catalyst is an amine catalyst. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 5996985

[Problems to be solved by invention]

The re-peelable adhesive sheet is required to have sufficient adhesion to the adherend when performing specific processing steps, and can be easily peeled off from the adherend after the specific processing step is completed (easy peelability), and the adhesive that adheres the sheet after peeling The layer is not transferred to the adherend (no residue). However, the conventional adhesive sheet does not completely satisfy the above conditions. In particular, when the adhesive sheet is attached to the adherend, the adherend is processed at a high temperature of about 200° C., and then irradiated with UV and peeled, it is likely to cause residue.

The present invention has been completed in view of the above circumstances, and the object is to provide an adhesive composition which is used as a material for forming an adhesive layer of an adhesive sheet and can obtain sufficient adhesive force to an adherend even if the adhesive sheet is adhered The body returns to room temperature after being in a high temperature state, and peels off after UV irradiation, and can also obtain excellent peelability, and at the same time, it is not easy to cause sticky sheets of residue. Moreover, the subject of this invention is providing the adhesive sheet which has the adhesive layer containing the said adhesive composition. [Means to solve the problem]

In order to solve the above-mentioned problems, the inventors have repeatedly reviewed actively. As a result, it was found that it is sufficient to use the following adhesive composition containing a carboxyl group-containing resin (b) obtained by polymerizing a carboxyl group-containing ethylenically unsaturated monomer (a) as an essential monomer component The resin (A) obtained by the addition reaction with the ethylenically unsaturated compound (c) containing an alicyclic epoxy group and the photopolymerization initiator (B) are essential components.

The adhesive composition containing the resin (A) and the photopolymerization initiator (B) has good heat resistance because the resin (A) has a structure derived from an alicyclic compound. In addition, the above-mentioned adhesive composition is irradiated with ultraviolet rays (UV) to harden unsaturated bonds in the resin (A) to form a three-dimensional cross-linked structure, thereby changing the adhesive force. Specifically, before the adhesive composition is irradiated with UV, sufficient adhesion to the adherend is obtained, and after UV irradiation, the adhesion is reduced to obtain excellent peelability, and at the same time, the residue on the adherend after peeling can be sufficiently prevented. The present inventors have conceived the present invention based on these findings. That is, the present invention relates to the following matters.

[1] An adhesive composition characterized by comprising a resin (A) represented by the following general formula (1-1) and a photopolymerization initiator (B),

(式(1-1)中，k、l、m、n係表示k+l+m+n=100時之莫耳組成比，k係超過0～92以下，l係0～50，m係超過0～90以下，k、l、m之合計為65～95，n為5～35，R¹ ～R⁴ 為-H或-CH₃ ，R⁵ 為碳數1～16之烷基，R⁶ 為碳數3～30之脂環式烴基或碳數6～20之芳香族烴基，R⁷ 為-H或-(CH₂ )_j -COOH(式中j為1或2)，R⁸ 為上述通式(1-2)或(1-3)，式(1-2)及(1-3)中，p及q係選自0、1、2之任一者，於p為0時s為0，於p為1或2時s為1，R⁹ 為-H或-CH₃ )。

(In formula (1-1), k, l, m, and n represent the molar composition ratio when k+l+m+n=100, k is more than 0 to 92 or less, l is 0 to 50, and m is More than 0 to 90 or less, the total of k, l, and m is 65 to 95, n is 5 to 35, R ¹ to R ⁴ are -H or -CH ₃ , R ⁵ is an alkyl group having 1 to 16 carbon atoms, R ⁶ is an alicyclic hydrocarbon group having 3 to 30 carbon atoms or an aromatic hydrocarbon group having 6 to 20 carbon atoms, R ⁷ is -H or -(CH ₂ ) _j -COOH (where j is 1 or 2), and R ⁸ is In the above general formula (1-2) or (1-3), in formulas (1-2) and (1-3), p and q are selected from any one of 0, 1, and 2, when p is 0 s is 0, s is 1 when p is 1 or 2, and R ⁹ is -H or -CH ₃ ).

[2] The adhesive composition according to [1], wherein the weight average molecular weight of the resin (A) is 200,000 to 1,000,000. [3] The adhesive composition according to [1] or [2], wherein n in the aforementioned formula (1-1) is 10 to 33. [4] The adhesive composition according to any one of [1] to [3], wherein k in the aforementioned formula (1-1) is 45 to 90, l is 4 to 40, and m is 1 to 15.

[5] The adhesive composition according to any one of [1] to [4], which further contains a crosslinking agent (C). [6] The adhesive composition according to any one of [1] to [5], wherein the glass transition temperature of the resin (A) is -80°C to 0°C.

[7] An adhesive sheet characterized by having a sheet-like substrate and an adhesive layer formed on the substrate, the adhesive layer comprising the adhesive composition of any one of [1] to [6]. [Effect of invention]

The adhesive composition of the present invention is used as a material for forming the adhesive layer of the adhesive sheet, and can obtain sufficient adhesion to the adherend even if the adherend to which the adhesive sheet is attached returns to room temperature after high temperature. After peeling off after UV irradiation, excellent peelability can also be obtained, and sticky flakes that are less prone to residue.

Hereinafter, the adhesive composition and adhesive sheet of the present invention will be described in detail. In addition, the present invention is not limited to the embodiments shown below. [Adhesive composition] The adhesive composition of this embodiment includes a resin (A) and a photopolymerization initiator (B). (Resin (A)) The resin (A) contained in the adhesive composition of this embodiment is a compound represented by the following general formula (1-1).

(式(1-1)中，k、l、m、n係表示k+l+m+n=100時之莫耳組成比，k係超過0～92以下，l係0～50，m係超過0～90以下，k、l、m之合計為65～95，n為5～35，R¹ ～R⁴ 為-H或-CH₃ ，R⁵ 為碳數1～16之烷基，R⁶ 為碳數3～30之脂環式烴基或碳數6～20之芳香族烴基，R⁷ 為-H或-(CH₂ )_j -COOH(式中j為1或2)，R⁸ 為上述通式(1-2)或(1-3)，式(1-2)及(1-3)中，p及q係選自0、1、2之任一者，於p為0時s為0，於p為1或2時s為1，R⁹ 為-H或-CH₃ )。

(In formula (1-1), k, l, m, and n represent the molar composition ratio when k+l+m+n=100, k is more than 0 to 92 or less, l is 0 to 50, and m is More than 0 to 90 or less, the total of k, l, and m is 65 to 95, n is 5 to 35, R ¹ to R ⁴ are -H or -CH ₃ , R ⁵ is an alkyl group having 1 to 16 carbon atoms, R ⁶ is an alicyclic hydrocarbon group having 3 to 30 carbon atoms or an aromatic hydrocarbon group having 6 to 20 carbon atoms, R ⁷ is -H or -(CH ₂ ) _j -COOH (where j is 1 or 2), and R ⁸ is In the above general formula (1-2) or (1-3), in formulas (1-2) and (1-3), p and q are selected from any one of 0, 1 and 2, when p is 0 s is 0, s is 1 when p is 1 or 2, and R ⁹ is -H or -CH ₃ ).

In formula (1-1), k, l, m, and n represent the molar composition ratio when k+l+m+n=100. The k system exceeds 0 to 92. l is 0-50. The m system exceeds 0 to 90 or less. The total of k, l, and m is 65 to 95. When the total of k, l, and m is 65 or more, it becomes an adhesive composition that obtains sufficient adhesion to the adherend before UV irradiation. The total of k, l, and m is preferably 70 to 94, more preferably 80 to 90.

In formula (1-1), the repeating unit (hereinafter referred to as "repeating unit k") represented by () in brackets k is the required repeating unit. The repeating unit k contributes to the adhesion of the adhesive composition before UV irradiation. The repeating number k of the repeating unit k is more than 0 to 92 or less, preferably 45 to 90, more preferably 60 to 88.

In formula (1-1), the repeating unit (hereinafter referred to as "repeating unit 1") represented by () in parentheses of l may not be required. In other words, the number of repetitions of the repetition unit 1 can be 0. The repeating unit l contributes to the heat resistance of the adhesive composition. The repeating number l of the repeating unit l is 0-50, preferably 4-40, and more preferably 5-30.

In formula (1-1), the repeating unit (hereinafter referred to as "repeating unit m") represented by () in brackets m is the required repeating unit. The repeating unit m contributes to the adhesive force and heat resistance of the adhesive composition before UV irradiation. Moreover, when the adhesive composition contains a cross-linking agent having a functional group that reacts with a carboxyl group, the repeating unit m can react with the cross-linking agent to improve the cohesive force of the adhesive composition. The repeating number m of the repeating unit m is more than 0 to 90 or less, preferably 1 to 15, and more preferably 1 to 5.

In formula (1-1), the repeating unit (hereinafter referred to as "repeating unit n") indicated by () in parentheses of n is the required repeating unit. The repeating unit n contributes to the heat resistance of the adhesive composition. The repeating number n of the repeating unit n is 5 to 35, preferably 10 to 33, and more preferably 10 to 20. When the repeating unit n is 35 or less, the unsaturated bond in the resin (A) forms a three-dimensional cross-linked structure by UV irradiation to be hardened, and becomes an adhesive composition whose adhesive strength is reduced to an appropriate range. In addition, when n is 5 or more, an effect of improving heat resistance due to the structure derived from the alicyclic compound is obtained.

By the synergistic effect of the functions assisted by these repeating units, the balance between the adhesive force of the adhesive composition containing the resin (A) before ultraviolet (UV) irradiation and the adhesive force after UV irradiation is better. As a result, it becomes an adhesive composition that obtains sufficient adhesive force to the adherend before UV irradiation and reduces the adhesive force after UV irradiation to obtain more excellent peelability. Moreover, even if the adhesive composition is returned to room temperature from a high temperature state before UV irradiation, the adhesive force will not become too high, and excellent peelability after UV irradiation is obtained, and the peeling is not likely to occur after peeling. Sticky residue.

In the repeating unit k, R ¹ is -H or -CH ₃ , preferably -H. R ⁵ is an alkyl group having 1 to 16 carbon atoms, preferably an alkyl group having 1 to 8 carbon atoms, and particularly preferably an alkyl group having 2, 4 or 8 carbon atoms.

The repeating unit k may also be a plurality of repeating units different in R ¹ and R ⁵ . When the repeating unit k includes plural types of repeating units, the molar composition ratio k of the repeating unit k represents the total of the molar composition ratios of the plural repeating units. For example, the repeating unit k includes repeating units A and B with different R ¹ and/or R ^{5. When} the repeating unit A has a molar composition ratio of 2 mole% and the repeating unit B has a molar composition ratio of 3 mole %, repeat The molar composition ratio k of the number k is the sum of the molar composition ratios of the repeating unit A and the repeating unit B and is "5".

In the repeating unit 1, R ² is -H or -CH ₃ , preferably -H. R ⁶ is an alicyclic hydrocarbon group having 3 to 30 carbon atoms or an aromatic hydrocarbon group having 6 to 20 carbon atoms, preferably an alicyclic hydrocarbon group having 6 to 20 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. The repeating unit l may also be a plurality of repeating units different in R ² and R ⁶ . When the repeating unit 1 includes plural kinds of repeating units, the molar composition ratio l of the repeating unit l represents the total of the molar composition ratios of the plural repeating units.

In the repeating unit m, R ³ is -H or -CH ₃ , preferably -H. R ⁷ is -H or -(CH ₂ ) _j -COOH (where j is 1 or 2), preferably -H. The repeating unit m may also be a plurality of repeating units different in R ³ and R ⁷ . In this case, the molar composition ratio m of the repeating unit m represents the sum of the molar composition ratios of the plural repeating units.

In the repeating unit n, R ⁴ is -H or -CH ₃ , preferably -H. R ⁸ is formula (1-2) or (1-3). The groups represented by the formula (1-2) or (1-3) all include a structure derived from an alicyclic compound, and have a function of improving the heat resistance of the adhesive composition. In formula (1-2) or (1-3), p and q are selected from any one of 0, 1, and 2. When p is 0, s is 0, and when p is 1 or 2, s is 1. R ⁹ is -H or -CH ₃ . The repeating unit n may also be a plurality of repeating units different in R ⁴ and R ⁸ . In this case, the molar composition ratio n of the repeating unit n represents the sum of the molar composition ratios of the plural repeating units.

The resin (A) represented by formula (1-1) may be any of random copolymers, block copolymers, and alternating copolymers formed by repeating unit k, repeating unit 1, repeating unit m, and repeating unit n By. The resin (A) represented by the formula (1-1) may not contain the repeating unit l, but the random copolymer, block copolymer, alternating copolymer formed by the repeating unit k, repeating unit m and repeating unit n Any one.

The weight average molecular weight of the resin (A) is preferably 200,000 to 1,000,000, more preferably 300,000 to 800,000. When the weight average molecular weight of the resin (A) is 200,000 or more, when the adhesive sheet having the adhesive layer containing the adhesive composition is attached to the adherend and peeled off, the adhesive layer is less likely to remain in the adherend. When the weight average molecular weight of the resin (A) is 1 million or less, the viscosity of the resin (A) will not be too high, and the effect of good workability is obtained. The weight average molecular weight of the resin (A) is measured according to the method described in the examples.

The glass transition temperature (Tg) of the resin (A) is preferably -80 to 0°C, more preferably -60 to 10°C, and still more preferably -50 to -10°C. When the glass transition temperature of the resin (A) is in the range of -80 to 0°C, the adhesive force of the adhesive composition before UV irradiation becomes good. The Tg of the resin (A) is a value measured according to the method described in the examples. The acid value of the resin (A) is preferably more than 0 to 20 mgKOH/g, more preferably 3 to 10 mgKOH/g. When the acid value of the resin (A) is in the range of more than 0 to 20 mgKOH/g, it is good without being contaminated (residue) by the adherend after heating. In addition, when the adhesive composition contains a crosslinking agent, if the acid value of the resin (A) is within the above range, the resin (A) and the crosslinking agent react to improve the cohesive force of the adhesive composition. The acid value of the resin (A) is a value measured according to the method described in the examples.

(Manufacturing method of resin (A)) The resin (A) contained in the adhesive composition of this embodiment can be produced by, for example, the method shown below. First, raw material monomers containing a carboxyl group-containing ethylenically unsaturated monomer (a) and an ethylenically unsaturated monomer (d) are polymerized to produce a carboxyl group-containing resin (b). Here, the ethylenically unsaturated monomer (d) is included in the monomer that forms the repeating unit k after polymerization, and may also include the monomer that forms the skeleton of the repeating unit 1. Next, the resin (A) is produced by the addition reaction of the carboxyl group-containing resin (b) and the ethylenically unsaturated compound (c) containing a specific alicyclic epoxy group.

(Carboxyl-containing ethylenically unsaturated monomer (a)) The carboxyl group-containing ethylenically unsaturated monomer (a) used in the production of the carboxyl group-containing resin (b) is a monomer which forms a skeleton of the repeating unit m by polymerization. The carboxyl group-containing ethylenically unsaturated monomer (a) has one carboxyl group. Examples of the carboxyl group-containing ethylenically unsaturated monomer (a) include (meth)acrylic acid, (meth)acrylic acid β-carboxyethyl ester, (meth)acrylic acid carboxypentyl ester, and the like. Among these, as the carboxyl group-containing ethylenically unsaturated monomer (a), based on the reactivity, (meth)acrylic acid and/or (meth)acrylic acid β-carboxyethyl ester are preferably used.

In this specification, "(meth)acrylic acid" means "acrylic acid" or "methacrylic acid". The term "(meth)acrylate" means "acrylate" or "methacrylate".

(Resin containing carboxyl group (b)) The carboxyl group-containing resin (b) is composed of at least a carboxyl group-containing ethylenically unsaturated monomer (a) and an ethylenically unsaturated monomer (d) copolymerizable with the carboxyl group-containing ethylenically unsaturated monomer (a) Raw material monomer copolymerization. The carboxyl group-containing resin (b) is a component that becomes the skeleton of the resin (A) represented by formula (1-1). The repeating unit k, repeating unit 1 and repeating unit m are all repeating units derived from the carboxyl group-containing resin (b).

As the ethylenically unsaturated monomer (d), one or more monomers which form a skeleton of the repeating unit k by polymerization are used. As the ethylenically unsaturated monomer (d), one or more monomers that form the skeleton of the repeating unit 1 by polymerization may be used together with the monomer that forms the skeleton of the repeating unit k by polymerization.

The ethylenically unsaturated monomer (d) which forms the skeleton of the repeating unit k by polymerization is a (meth)acrylic acid alkyl ester having 1 to 16 carbon atoms. From the viewpoint of adjusting the peel strength of the adhesive composition, It preferably contains (meth)acrylic acid alkyl esters having 2 to 16 carbon atoms, and more preferably contains (meth)acrylic acid alkyl esters having 4 to 12 carbon atoms. Specifically, examples are methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, third butyl (meth)acrylate, Isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, n-hexyl (meth)acrylate, isooctyl (meth)acrylate, (methyl ) Lauryl acrylate, etc. Among these, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isopropyl (meth)acrylate Octyl ester.

Examples of the ethylenically unsaturated monomer (d) which forms the skeleton of the repeating unit 1 by polymerization are, for example, (meth)acrylates containing a cyclic alkyl group having 3 to 30 carbon atoms, and those containing 6 to 20 carbon atoms. (Meth) acrylates of aromatic groups.

Examples of (meth)acrylates containing a cyclic alkyl group having 3 to 30 carbon atoms as the ethylenically unsaturated monomer (d) that forms a skeleton of the repeating unit 1 by polymerization are, for example, (meth)acrylic acid Cyclohexyl ester, norbornene (meth)acrylate, isobornyl (meth)acrylate, norbornene (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclo (meth)acrylate Pentenyloxyethyl, dicyclopentyl (meth)acrylate, dicyclopentyloxyethyl (meth)acrylate, tricyclodecane dimethylol di(meth)acrylate, etc. Among these, isobornyl (meth)acrylate is particularly preferably used. When the raw material monomer of the carboxyl group-containing resin (b) contains a cyclic alkyl (meth)acrylate, the adhesive composition containing the resin (A) produced using the carboxyl group-containing resin (b) has good heat resistance.

The (meth)acrylate containing an aromatic group having 6 to 20 carbon atoms used as the ethylenically unsaturated monomer (d) which forms the skeleton of the repeating unit 1 by polymerization is, for example, benzyl (meth)acrylate Ester, phenoxyethyl (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, phenoxypropyl (meth)acrylate, phenoxypolypropylene glycol (meth)acrylate, etc. . Among these, benzyl (meth)acrylate is particularly preferably used. When the raw material monomer of the carboxyl group-containing resin (b) contains an aromatic group-containing (meth)acrylate, the adhesive composition containing the resin (A) produced using the carboxyl group-containing resin (b) has good heat resistance .

The raw material monomer of the carboxyl group-containing resin (b) is not only the above carboxyl group-containing ethylenically unsaturated monomer (a) and the above ethylenically unsaturated monomer (d), but also the above ethylenically unsaturated monomer (d) Other monomers copolymerizable with carboxyl group-containing ethylenically unsaturated monomer (a).

Examples of the ethylenically unsaturated monomer which can be copolymerized with the carboxyl group-containing ethylenically unsaturated monomer (a) other than the above ethylenically unsaturated monomer (d) are alkoxyalkyl (meth)acrylate, alkyl Oxy(poly)alkanediol (meth)acrylate, hydroxyl-containing (meth)acrylate, fluorinated alkyl (meth)acrylate, dialkylaminoalkyl (meth)acrylate, (methyl ) Acrylamide etc.

Examples of alkoxyalkyl (meth)acrylates are, for example, ethoxyethyl (meth)acrylate, methoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, (methyl ) 2-Methoxyethoxyethyl acrylate, 2-ethoxyethoxyethyl (meth)acrylate and the like.

Examples of alkoxy (poly) alkanediol (meth)acrylates are, for example, methoxydiethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, (methyl) ) Methoxy dipropylene glycol acrylate, etc.

Examples of hydroxyl-containing (meth)acrylates are, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, (meth) 1,3-Butanediol acrylate, 1,4-butanediol (meth)acrylate, 1,6-hexanediol (meth)acrylate, 3-methylpentanediol (meth)acrylate Ester etc.

Examples of fluorinated alkyl (meth)acrylates include octafluoropentyl (meth)acrylate and the like. Examples of the dialkylaminoalkyl (meth)acrylate include N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, and the like.

Examples of (meth)acrylamide include (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, and N-propyl(methyl ) Acrylamide, N-isopropylacrylamide, N-hexyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N,N-diethyl (methyl) ) Acrylamide, (meth)acrylamide morpholine, diacetone acrylamide, etc.

Examples of monomers other than the ethylenically unsaturated monomer (d) that can be copolymerized with the carboxyl group-containing ethylenically unsaturated monomer (a) are acrylonitrile, methacrylonitrile, styrene, α-methylstyrene, vinyl acetate, vinyl propionate, vinyl stearate, vinyl chloride, vinylidene chloride, alkyl vinyl ether, vinyl toluene, N-vinylpyridine, N-vinylpyrrole Pyridone, dialkyl itaconate, dialkyl fumarate, allyl alcohol, hydroxybutyl vinyl ether, hydroxyethyl vinyl ether, 4-hydroxymethylcyclohexylmethyl vinyl ether, triethyl Glycol monovinyl ether or diethylene glycol monovinyl ether, methyl vinyl ketone, allyl trimethyl ammonium chloride, dimethyl allyl vinyl ketone, etc.

The method for producing the carboxyl group-containing resin (b) is not particularly limited. For example, the raw material monomer containing the carboxyl group-containing ethylenically unsaturated monomer (a) and the ethylenically unsaturated monomer (d) as the constituent components of the carboxyl group-containing resin (b) can be copolymerized by a conventional polymerization method Got. Specifically, as the polymerization method, a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, a suspension polymerization method, an alternating copolymerization method, or the like can be used. In these polymerization methods, considering the addition reaction of the carboxyl group-containing resin (b) obtained after the polymerization and the alicyclic epoxy group-containing ethylenically unsaturated compound (c), from the viewpoint of ease of reaction, Solution polymerization is good.

When producing the carboxyl group-containing resin (b) by the solution polymerization method, a radical polymerization initiator and/or a solvent are used as necessary. The radical polymerization initiator is not particularly limited, and can be appropriately selected and used by those skilled in the art. As a radical polymerization initiator, 2,2'-azobis (isobutyronitrile), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2 can be exemplified ,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1 -Carbonitrile), 2,2'-azobis (2,4,4-trimethylpentane), 2,2'-azobis (2-methylpropionate), etc. Starter; benzoyl peroxide, third butyl hydroperoxide, di-third butyl peroxide, third butyl peroxybenzoate, dicumyl peroxide, 1,1 -Peroxide polymerization of bis(tert-butylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis(tert-butylperoxy)cyclododecane, etc. Oil-soluble polymerization initiator such as initiator.

These radical polymerization initiators can be used alone or in combination of two or more. The amount of the radical polymerization initiator used is preferably 0.01 to 5 parts by mass, more preferably 0.02 to 4 parts by mass, and more preferably 100 parts by mass of the raw material monomers of the carboxyl group-containing resin (b). 0.03～3 parts by mass.

As a solvent for polymerization used in the production of the carboxyl group-containing resin (b), general various solvents can be used. Examples of the solvent include esters such as ethyl acetate, n-propyl acetate, and n-butyl acetate; aromatic hydrocarbons such as toluene, xylene, and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; Alicyclic hydrocarbons such as hexane and methylcyclohexane; ketones such as methyl ethyl ketone and methyl isobutyl ketone; glycols such as ethylene glycol, propylene glycol and dipropylene glycol; methyl cellosolve Glycol ethers such as selenium, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, etc.; glycol esters of ethylene glycol diacetate, propylene glycol monomethyl ether acetate, etc. These solvents can be used alone or in combination of two or more.

When manufacturing carboxyl group-containing resin (b), carboxyl group-containing raw material monomers containing carboxyl group-containing ethylenically unsaturated monomers (a) and ethylenically unsaturated monomers (d) and other monomers as required The content of the ethylenically unsaturated monomer (a) is preferably 5 to 40% by mass, more preferably 7 to 30% by mass, and still more preferably 10 to 25% by mass. By containing the carboxyl group-containing ethylenically unsaturated monomer (a) in the raw material monomer in the above range, self-contained by using the carboxyl group-containing resin (b) and the alicyclic epoxy group-containing ethylenically unsaturated compound (c) The addition reaction of the adhesive composition of the resin (A) produced by the addition reaction has good adhesion before UV irradiation.

(Ethylene unsaturated compound containing alicyclic epoxy group (c)) The ethylenically unsaturated compound containing an alicyclic epoxy group (c) is an ethylenically unsaturated group compound having an alicyclic epoxy group, which can be given to the general formula (1-2) or the general formula (1-3) The structure of the compound. The alicyclic epoxy group in this embodiment means an epoxy group formed by bonding one oxygen to two adjacent carbon atoms on the ring of the alicyclic hydrocarbon compound. The ethylenically unsaturated compound (c) containing an alicyclic epoxy group is the following partial structural formula (1-2) for the repeating unit n of the photosensitive resin (A) represented by the addition formula (1-1) ') or (1-3'). The partial structural formula (1-2') or (1-3') in the repeating unit n in formula (1-1) is derived from the base of the ethylenically unsaturated compound (c) containing an alicyclic epoxy group .

(式(1-2’)及(1-3’)中，q係選自0、1、2之任一者，R⁹ 為-H或-CH₃ )。

(In formulas (1-2') and (1-3'), q is any one selected from 0, 1 and 2, and R ⁹ is -H or -CH ₃ ).

Examples of the alicyclic epoxy group-containing ethylenically unsaturated compound (c) include compounds represented by the following formula (1) or (2).

(式(1)中，R⁹ 為-H或-CH₃ ，q係選自0、1、2之任一者)。 (式(2)中，R⁹ 為-H或-CH₃ ，q係選自0、1、2之任一者)。

(In formula (1), R ⁹ is -H or -CH ₃ , and q is any one selected from 0, 1 and 2). (In formula (2), R ⁹ is -H or -CH ₃ , and q is any one selected from 0, 1 and 2).

In formula (1), R ⁹ is -H or -CH ₃ , q is any one selected from 0, 1 and 2, and q is preferably 1. In formula (2), R ⁹ is -H or -CH ₃ , q is any one selected from 0, 1 and 2, and q is preferably 1.

The ethylenically unsaturated compound (c) containing an alicyclic epoxy group is preferably a compound represented by the formula (1), and 3,4-epoxycyclohexyl methyl (meth)acrylate is particularly preferably used. As the ethylenically unsaturated compound (c) containing an alicyclic epoxy group, only one type may be used, or two or more types may be used in combination.

In the resin (A) of this embodiment, an alicyclic epoxy group containing an alicyclic epoxy group-containing ethylenically unsaturated monomer (c) can be added to the carboxyl group of the carboxyl group-containing resin (b). And manufacture. The resin (A) is preferably an addition reaction of 0.2 to 0.99 mol, more preferably 0.3 to 0.95 mol, and even more preferably 0.6 to 0.95 mol of an alicyclic epoxy group to 1 mol of the carboxyl group of the carboxyl group-containing resin (b). Manufactured from ethylenically unsaturated compound (c). The adhesive composition containing the resin (A) containing a carboxyl group and the ethylenically unsaturated compound (c) containing an alicyclic epoxy group (c) in the above ratio is used to obtain an adherend before UV irradiation Fully adhesive, the adhesive strength is reduced after UV irradiation to obtain more excellent peelability. Moreover, even if the adhesive composition is in a high temperature state before UV irradiation and then returns to room temperature, the adhesive force is not likely to become high, and excellent ease of peelability after UV irradiation is obtained, and it can more effectively prevent the adhesive from being peeled off. Sticky residue.

The addition reaction temperature when producing the resin (A) is preferably 80 to 130°C, and particularly preferably 90 to 120°C. If the addition reaction temperature is 80°C or higher, a sufficient reaction rate is obtained. If the addition reaction temperature is 130° C. or lower, it is possible to prevent the double bond portion from crosslinking due to thermal radical polymerization and generating a gel.

In the addition reaction when manufacturing the resin (A), a conventional catalyst can be used as necessary. Examples of catalysts are, for example, triethylamine, tributylamine, dimethylbenzylamine, 1,8-diazabicyclo[5,4,0]undec-7-ene, 1,5-diaza Tertiary amines such as heterobicyclo[4,3,0]non-5-ene, 1,4-diazabicyclo[2,2,2]octane; tetramethylammonium chloride, tetramethyl bromide Grade 4 ammonium salts such as ammonium and tetrabutylammonium bromide; alkylureas such as tetramethylurea; alkylguanidines such as tetramethylguanidine; triphenylphosphine, dimethylphenylphosphine, tricyclohexylphosphine, Tributylphosphine, tri(4-methylphenyl)phosphine, tri(4-methoxyphenyl)phosphine, tri(2,6-dimethylphenyl)phosphine, tri(2,6-dimethylmethyl Phosphine compounds such as oxyphenyl)phosphine, tri(2,4,6-trimethylphenyl)phosphine, tri(2,4,6-trimethoxyphenyl)phosphine, etc. As the catalyst for the addition reaction, among the above, from the viewpoint of reactivity, a phosphine compound is preferably used.

The amount of catalyst used in the addition reaction is preferably 0.01 to 30 parts by mass relative to 100 parts by mass of the total of the carboxyl group-containing resin (b) and the alicyclic epoxy group-containing ethylenically unsaturated monomer (c). Parts, more preferably 0.05 to 5 parts by mass, most preferably 0.1 to 2 parts by mass.

In addition, during the addition reaction, a gas having a polymerization inhibitory effect may be introduced into the reaction system, and a polymerization inhibitor may be added. By introducing a gas having a polymerization inhibitory effect or adding a polymerization inhibitor to the reaction system, gelation during the addition reaction can be prevented. As the gas having a polymerization inhibitory effect, for example, a gas containing oxygen to such an extent that it does not cause an explosion range of substances in the system, such as air, etc.

Known ones can be used as polymerization inhibitors and are not particularly limited, but examples thereof include 4-methoxyphenol, hydroquinone, methoxyphenol, 2,6-di-tert-butylphenol, 2,2 '-Methylenebis (4-methyl-6-third butylphenol), phenothiazine, etc. One type of these polymerization inhibitors may be used alone, or two or more types may be used in combination.

The use amount of the polymerization inhibitor is preferably 0.005 to 5 parts by mass relative to the total of 100 parts by mass of the carboxyl group-containing resin (b) and the alicyclic epoxy group-containing ethylenically unsaturated monomer (c). It is preferably 0.03 to 3 parts by mass, and preferably 0.05 to 1.5 parts by mass. When the amount of the polymerization inhibitor is too small, the polymerization inhibitory effect may be insufficient. On the other hand, if the amount of the polymerization inhibitor is too large, the exposure sensitivity of the resin (A) may decrease. Furthermore, when a gas having a polymerization inhibitory effect and a polymerization inhibitor are used in combination, it is preferable because the amount of the polymerization inhibitor used can be reduced and the polymerization inhibitory effect can be improved.

(Photopolymerization initiator (B)) Examples of the photopolymerization initiator (B) contained in the adhesive composition include, for example, benzophenone, benzil, benzoin, ω-bromoacetophenone, chloroacetone, and acetophenone. , 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, p-dimethylaminoacetophenone, p-dimethylaminoacetophenone, 2 -Chlorobenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone, Mickael ketone, benzin methyl ether, benzoin Isobutyl ether, benzoin n-butyl ether, benzyl methyl acetal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one, methyl benzoyl carboxylate, 2,2-diethoxyacetophenone, 4-N, Carbonyl photopolymerization initiators such as N'-dimethylacetophenone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinylpropane-1-one and the like.

As the photopolymerization initiator (B), thioether-based photopolymerization such as diphenyl disulfide, dibenzyl disulfide, tetraethyl thiuram disulfide, and tetramethyl ammonium monosulfide can also be used Starter; 2,4,6-trimethylbenzyl diphenylphosphine oxide, 2,4,6-trimethylbenzylphenyl ethoxyphosphine oxide, etc. Oxides; quinone-based photopolymerization initiators such as benzoquinone and anthraquinone; sulfonyl chloride-based photopolymerization initiators; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, etc. Department of photopolymerization initiators.

Among these photopolymerization initiators (B), from the viewpoint of solubility in the adhesive composition, 1-hydroxycyclohexyl phenyl ketone and/or 2,4,6-trimethylbenzophenone are preferably used Diphenylphosphine oxide. The photopolymerization initiator (B) may be used alone, or two or more kinds may be used in combination.

The photopolymerization initiator (B) contained in the adhesive composition is preferably 0.1 to 5.0 parts by mass, more preferably 0.5 to 2.0 parts by mass with respect to 100 parts by mass of the resin (A). If the content of the photopolymerization initiator (B) relative to 100 parts by mass of the resin (A) is 0.1 parts by mass or more, the adhesive composition is cured at a sufficiently rapid curing rate by irradiation with UV, and after UV irradiation The adhesive force of the adhesive composition is sufficiently small and preferable. If the content of the photopolymerization initiator (B) is 5.0 parts by mass or less, an adhesive sheet having an adhesive layer containing an adhesive composition will not easily remain in the adherend when it is peeled off after being attached to the adherend . In addition, even if the content of the photopolymerization initiator (B) exceeds 5.0 parts by mass, no effect consistent with the content of the photopolymerization initiator (B) is seen.

(Crosslinking agent (C)) The adhesive composition of this embodiment contains not only a resin (A) and a photopolymerization initiator (B), but also a crosslinking agent (C). By containing a cross-linking agent (C), it can become an adhesive composition with a better balance between the adhesive force before UV irradiation and the adhesive force after UV irradiation. The crosslinking agent (C) is not particularly limited, but it is preferably a compound having two or more functional groups having a reactive group for the hydroxyl group of the repeating unit n, or the hydroxyl group of the repeating unit n, and the carboxyl group of the repeating unit m.

Examples of the crosslinking agent (C) include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, hydrogenated toluene diisocyanate, 1,3-xylene diisocyanate, and 1,4-xylene diisocyanate. , Diphenylmethane-4,4-diisocyanate, isophorone diisocyanate, 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane, 1,3-bis(isocyanate Methyl) cyclohexane, isocyanurate of hexamethylene diisocyanate, tetramethyl xylene diisocyanate, 1,5-naphthalene diisocyanate, toluene diisocyanate adduct of trimethylolpropane , Xylene diisocyanate adducts of trimethylolpropane, isocyanate compounds such as triphenylmethane triisocyanate, methylene bis(4-phenylmethane) triisocyanate; Bisphenol A, epichlorohydrin type epoxy resin, N,N'-[1,3-phenylenebis(methylene)]bis[bis(oxysilan-2-ylmethyl)amine], ethyl Glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, Epoxy compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl erythritol, diglycerol polyglycidyl ether, etc.; Tetramethylolmethane-tri-β-acridinyl propionate, trimethylolmethane-tri-β-acridinyl propionate, N,N'-diphenylmethane-4,4'-bis (1-acridinyl carboxyamide), N,N'-hexamethylene-1,6-bis(1-acridinylcarboxyamide) and other acridine compounds; Melamine series such as hexamethoxymethyl melamine, hexaethoxymethyl melamine, hexapropoxymethyl melamine, hexapropoxymethyl melamine, hexapentoxymethyl melamine, hexahexyloxymethyl melamine, etc. Compounds, etc.

Among these, as the crosslinking agent (C), the epoxy-based compound and/or the isocyanate-based compound is preferably used because of its good reactivity with the resin (A). The above-mentioned crosslinking agent (C) may be used alone or in combination of two or more.

The crosslinking agent (C) contained in the adhesive composition is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and still more preferably 0.1 to 1.0 with respect to 100 parts by mass of the resin (A). Quality parts. If the content of the crosslinking agent (C) with respect to 100 parts by mass of the resin (A) is 0.05 parts by mass or more, a three-dimensional crosslinked structure is sufficiently formed in the adhesive composition. As a result, the adhesive force of the adhesive composition after UV irradiation is sufficiently reduced and is preferable. If the content of the crosslinking agent (C) with respect to 100 parts by mass of the resin (A) is 10 parts by mass or less, the adhesive force of the adhesive composition before UV irradiation becomes good.

(Other ingredients) The adhesive composition of this embodiment may contain components other than the resin (A), the photopolymerization initiator (B), and the cross-linking agent (C), if necessary. Examples of other components include adhesion-imparting agents, solvents, and various additives.

(Adhesion-imparting agent) As the adhesion-imparting agent, conventional ones can be used without particular limitation. Examples of the adhesion-imparting agent include terpene-based adhesion-imparting resins, phenol-based adhesion-imparting resins, rosin-based adhesion-imparting resins, aliphatic petroleum resins, aromatic petroleum resins, copolymerized petroleum resins, and alicyclic petroleum resins. , Xylene resin, epoxy-based adhesion-imparting resin, polyamide-based adhesion-impartment resin, ketone-based adhesion-impartment resin, elastic-system adhesion-impartment resin, etc. These adhesion-imparting agents may be used alone or in combination of two or more.

When the adhesive composition of this embodiment contains an adhesion-imparting agent, its content is preferably 30 parts by mass or less relative to 100 parts by mass of the resin (A), and more preferably 5 to 20 parts by mass.

(Solvent) When the solvent is applied to the adhesive composition, the viscosity of the adhesive composition can be adjusted for the purpose of diluting the adhesive composition. As the solvent, for example, methyl ethyl ketone, methyl isobutyl ketone, acetone, ethyl acetate, n-propyl acetate, tetrahydrofuran, dioxane, cyclohexanone, n-hexane, toluene, xylene, n-propanol , Isopropyl alcohol and other organic solvents. These solvents may be used alone or in combination of two or more.

(additive) Examples of additives include plasticizers, surface lubricants, leveling agents, softeners, antioxidants, anti-aging agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, benzotriazole-based light stabilizers, phosphoric acid, etc. Ester and other flame retardants, surfactant-like antistatic agents, etc.

[Manufacturing method of adhesive composition] The adhesive composition of this embodiment can be manufactured by a conventionally known method. For example, the above-mentioned resin (A) and the photopolymerization initiator (B) and the crosslinking agent (C), the adhesion-imparting agent, the solvent, and various additives contained as needed can be mixed and stirred using conventionally known methods.

The adhesive composition of this embodiment can be preferably used as a material for forming an adhesive layer of an adhesive sheet. In particular, the adhesive composition of this embodiment can be preferably used as a material for forming an adhesive layer of a re-peelable adhesive sheet. Since the adhesive composition of this embodiment contains the resin (A) represented by the formula (1-1) and the photopolymerization initiator (B), by using the material as the adhesive layer forming the adhesive sheet, the Adhesive sheet with sufficient adhesive force. Moreover, even if the adherend to which the adhesive sheet is attached is in a high-temperature state and returns to room temperature and peels off, the excellent peelability after UV irradiation can be obtained, and residue is less likely to occur.

[Adhesive sheet] The adhesive sheet of the present invention has a sheet-shaped substrate and an adhesive layer formed on the substrate. It is preferable to provide a release sheet (release sheet) on the surface of the adhesive layer opposite to the substrate. When a peeling sheet is provided on the adhesive layer, the peeling sheet can protect the adhesive layer before use. In addition, when a peeling sheet is provided on the adhesive layer, the peeling sheet can be efficiently peeled to expose the adhesive layer, and the operation of pressing the adhesive layer (adhesive surface) against the adherend can be performed. The adhesive sheet of the present embodiment can also be used as an adhesive tape having a shape corresponding to the shape of an adherend by a stamping method or the like. Moreover, the adhesive sheet of this embodiment can also be used as an adhesive tape by winding and cutting.

As the base material, conventional sheet-like materials can be appropriately selected and used. As the base material, a resin sheet made of a transparent resin material or the like is preferably used. Examples of resin materials include polyolefins such as polyethylene (PE) and polypropylene (PP); polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polynaphthalene dicarboxylic acid Polyester flakes such as ethylene glycol; polyvinyl chloride (PVC); polyimide (PI); polyphenylene sulfide (PPS); ethylene vinyl acetate (EVA); polytetrafluoroethylene (PTFE), etc. Among these resin materials, in order to obtain a sheet with moderate flexibility, PE, PP, and PET are preferably used. Only one type of resin material may be used alone, or two or more types may be used in combination.

When a resin sheet is used as a base material, the resin sheet may be a single layer or a multilayer structure with two or more layers (for example, a three-layer structure). In a resin sheet having a multi-layer structure, the resin material constituting each layer may include only one type of resin material alone, or may contain more than two types of resin material.

The thickness of the substrate can be appropriately selected according to the application of the adhesive sheet, the material of the substrate, and the like. The adhesive sheet protects the wafer during the wafer dicing step. When a resin sheet is used as the substrate, the substrate thickness is preferably, for example, 10 to 1000 μm, more preferably 50 to 300 μm. When the thickness of the base material is 10 μm or more, the rigidity of the adhesive sheet becomes higher (stronger strength). Therefore, when the adhesive sheet is attached to an adherend such as a wafer, the adhesive sheet tends to be less likely to wrinkle or swell when peeled from the adherend. In addition, when the thickness of the base material is 10 μm or more, the adhesive sheet attached to the adherend is easily peeled off from the adherend, and the workability (operability and handling) is good. When the thickness of the substrate is 1000 μm or less, the rigidity of the adhesive sheet can be prevented from becoming too high (strong strength), and the workability is reduced.

When a resin sheet is used as a base material, a conventionally well-known general sheet forming method (for example, extrusion molding, T die forming, blow molding, etc., or uniaxial or biaxial stretch forming, etc.) can be suitably used to produce the substrate.

The surface of the substrate on the side in contact with the adhesive layer may also be subjected to surface treatment to improve the adhesion between the substrate and the adhesive layer. Examples of the surface treatment include corona discharge treatment, acid treatment, ultraviolet irradiation treatment, plasma treatment, and primer coating.

The adhesive layer included in the adhesive sheet of this embodiment includes the adhesive composition described above. The thickness of the adhesive layer is preferably 1 to 100 μm, more preferably 2 to 80 μm, and still more preferably 5 to 50 μm. When the thickness of the adhesive layer is 1 μm or more, the uniformity of the thickness of the adhesive layer is good. On the other hand, when the thickness of the adhesive layer is 100 μm or less, when a solvent is used to form the adhesive layer, the solvent can be easily removed, which is preferable.

When a peeling sheet is provided on the surface of the adhesive layer opposite to the substrate, a conventional sheet-like material can be appropriately selected and used as the peeling sheet. As the release sheet, the same resin sheet as the above-mentioned resin sheet used as the base material can be used. The thickness of the peeling sheet can be appropriately selected according to the application of the adhesive sheet and the material of the peeling sheet. When a resin sheet is used as the release sheet, the thickness of the release sheet is preferably, for example, 5 to 300 μm, more preferably 10 to 200 μm, and still more preferably 25 to 100 μm.

On the peeling surface of the peeling sheet (the surface disposed in contact with the adhesive layer), a conventionally known peeling agent such as a silicone-based, long-chain alkyl-based, or fluorine-based peeling agent may be used as necessary.

[Manufacturing method of adhesive sheet] The adhesive sheet of this embodiment can be manufactured by the following method, for example. First, an adhesive solution is prepared in which the above adhesive composition is dissolved or dispersed in a solvent. The above adhesive composition can be directly used as an adhesive solution. Secondly, apply the adhesive solution on the substrate, heat and dry to form an adhesive layer. Subsequently, it is obtained by attaching a peeling sheet on the adhesive layer as needed. In addition, as another method of manufacturing the adhesive sheet of the present embodiment, for example, the above adhesive solution is coated on the peeling sheet, and dried by heating to form an adhesive layer. Subsequently, a peeling sheet with an adhesive layer is provided on the substrate with the adhesive layer side facing the substrate, and the adhesive layer is transferred (moved to the adhesive) on the substrate.

A conventional method can be used for the method of applying the above-mentioned adhesive solution on the substrate (or on the release sheet). Specifically, for example, a conventional coater such as a concave-convex roll coater, a reverse roll coater, a touch roll coater, a dip roll coater, a bar coater, a blade coater, spray coating is used Coating method such as coating machine, corner wheel coating machine, direct roll coating machine, etc.

[Use of Adhesive Sheet] The adhesive sheet of this embodiment can be used as a re-peelable adhesive sheet. The adhesive sheet of this embodiment can be used, for example, when manufacturing electronic parts. The adhesive sheet of the present embodiment is specifically used for fixing an adherend in various steps when manufacturing an electronic component, delivering it to various processing steps, irradiating ultraviolet rays (UV), peeling the adherend and recycling it. Therefore, the adhesive sheet of this embodiment can be used as a back-grinding tape, dicing tape, etc. during semiconductor wafer processing. In addition, the adhesive sheet of the present embodiment can be preferably used as a support tape for a warp member such as a fragile member such as an ultra-thin glass substrate, a plastic film, or a flexible printed circuit board (FPC substrate). In particular, the adhesive sheet of this embodiment can be preferably used as a dicing tape that protects the wafer during the dicing step of the wafer.

When the adhesive sheet of this embodiment is used as a dicing tape for a wafer, before performing the dicing step, the adhesive sheet is attached to a wafer on which a plurality of parts are formed. Next, the wafer is cut and diced (cut) into individual parts to become small pieces of chips (wafers). Subsequently, the adhesive sheet attached to each element die was irradiated with UV. In this way, the adhesive layer is irradiated with UV through the substrate of the adhesive sheet, so that the unsaturated bond in the adhesive forms a three-dimensional cross-linked structure and is hardened. As a result, the adhesive force of the adhesive layer is reduced. Subsequently, the adhesive sheet was peeled from each element die.

Examples of light sources used when performing UV irradiation on the adhesive sheet attached to the adherend before peeling are, for example, high-pressure mercury lamps, ultra-high-pressure mercury lamps, carbon arc lamps, xenon lamps, metal halogen lamps, chemical lamps, and black light. The UV irradiation amount irradiated to the adhesive sheet is preferably 50 to 3000 mJ/cm ² , more preferably 100 to 600 mJ/cm ² . When the UV irradiation amount of the adhesive sheet is 50 mJ/cm ² or more, the adhesive layer can be hardened by UV irradiation at a sufficiently fast curing speed, and the adhesive force of the adhesive layer after UV irradiation becomes sufficiently small and preferably. Even if the UV irradiation amount irradiated to the adhesive sheet is 3000 mJ/cm ² or more, the effect corresponding to it cannot be obtained. [Example]

Hereinafter, the present invention will be further specifically described by Examples and Comparative Examples. In addition, the present invention is not limited to the following examples.

[Manufacture of Resin (A)] (Production Example 1) [Preparation of the first mixed solution] As shown in Table 1, a first mixed solution containing 23.9 parts by mass of acrylic acid containing a carboxyl group-containing ethylenically unsaturated monomer (a) and an ethylenically unsaturated monomer (d) copolymerizable with the above (a) was prepared ) 71.8 parts by mass of n-butyl acrylate and 143.6 parts by mass of 2-ethylhexyl acrylate and 0.1 parts by mass of the total monomers relative to 100 parts by mass of the raw material monomer of the carboxyl group-containing resin (b) The starting agent of 2,2'-azobisisobutyronitrile.

[Preparation of the second mixed solution] As shown in Table 1, a second mixed solution was prepared, which contained 39.8-epoxycyclohexyl methyl methacrylate containing 59.8 parts by mass of 3,4-epoxycyclohexyl methacrylate containing an ethylenically unsaturated compound (c) containing an alicyclic epoxy group. Tris(4-methylphenyl)phosphine (0.6-mass parts of catalyst) is added to the total of 100 parts by mass of resin containing carboxyl group (b) and alicyclic epoxy group-containing ethylenically unsaturated monomer (c) ( TPTP) and 100.0 parts by mass of n-butyl acetate and 91.1 parts by mass of toluene as solvents.

In a four-necked flask equipped with a stirrer, a dropping funnel, a cooling tube, and a nitrogen introduction tube, 175.6 parts by mass of n-butyl acetate as a solvent was fed, and the temperature was raised to 80°C under a nitrogen atmosphere. Next, while maintaining the reaction temperature at 80°C±2°C, the first mixed solution was added dropwise to the four-necked flask over 4 hours, and after the completion of the dropwise addition, the stirring was continued at a temperature of 80°C±2°C. Hour, the carboxyl group-containing resin (b) is polymerized. Subsequently, in the reaction system, 0.15 parts by mass relative to the total 100 parts by mass of the carboxyl group-containing resin (b) and the alicyclic epoxy group-containing ethylenically unsaturated monomer (c) is added as a polymerization inhibitor 4-methoxyphenol.

The reaction system to which 4-methoxyphenol was added was raised to 100°C, and the second mixed solution was added dropwise over 0.5 hours, followed by continuous stirring at 100°C for 8 hours to synthesize the resin (A-1) and cool to room Temperature (23°C). The resin (A-1) was identified by the nuclear magnetic resonance method (NMR method), and was a compound represented by the general formula (2-1). In the compound represented by the general formula (2-1), the repeating unit k of the formula (1-1) is two kinds of repeating units (k-1, k-2) different in R ⁵ .

(式(2-1)中，k-1為34，k-2為47，m為1，k-1、k-2、m之合計為82，n為18)。

(In formula (2-1), k-1 is 34, k-2 is 47, m is 1, the total of k-1, k-2, and m is 82, and n is 18).

For the resin (A-1), the weight average molecular weight and glass transition temperature were investigated by the method shown below. In addition, the acid value of the resin (A-1) is measured according to JIS K0070. The results are shown in Table 3.

<weight average molecular weight (Mw)> Using a gel permeation chromatograph (Showa Denko Co., Ltd., Shodex (registered trademark) GPC-101), it was measured at room temperature under the following conditions and calculated in terms of polystyrene. Pipe column: Showa Denko Co., Ltd., Shodex (registered trademark) LF-804 Column temperature: 40℃ Sample: 0.2 mass% tetrahydrofuran solution of resin (A) Flow rate: 1ml/min Dissolution solution: tetrahydrofuran Detector: RI detector

＜Glass transition temperature (Tg)＞ A sample of 10 mg was taken from resin (A). Using a differential scanning calorimeter (DSC), the temperature of the sample was changed from -100°C to 200°C at a heating rate of 10°C/minute, and differential scanning calorimetry was performed, and the endothermic start temperature due to the observed glass transition was taken as Tg. In addition, when two Tgs are observed, it is set as a simple average value of two Tgs.

(Production Examples 2-8, 10-12) In addition to the contents (parts by mass) shown in Tables 1 and 2, the carboxyl group-containing ethylenically unsaturated monomer (a), the ethylenically unsaturated monomer (d) and the polymerization initiator were used, as in Production Example 1. Similarly, the first mixed solution was prepared. In addition, in addition to the content (parts by mass) shown in Table 1 and Table 2, an alicyclic epoxy group-containing ethylenically unsaturated compound (c) (glycidyl methacrylate (GMA) in Production Example 8) was used ) The second mixed solution was prepared in the same manner as in Production Example 1 except for the catalyst.

Except for using the first mixed solution and the second mixed solution, in the same manner as in Production Example 1, resins (A-2) to (A-8) and (A-10) to (A-12) were obtained. The resins (A-2) to (A-8) and (A-10) to (A-12) were identified by the same results as in Production Example 1, and were general formulas (2-2) to (2-8), Compounds represented by (2-10) to (2-12). In the compounds represented by the general formulae (2-2) to (2-8) and (2-10), the repeating unit k of the formula (1-1) is R ⁵ or two different types of R ¹ and R ⁵ Repeating units (k-1, k-2).

The resin (A-2) is a compound represented by the following general formula (2-2). The resin (A-3) is a compound represented by the following general formula (2-3). The resin (A-4) is a compound represented by the following general formula (2-4). The resin (A-5) is a compound represented by the following general formula (2-5). The resin (A-6) is a compound represented by the following general formula (2-6). The resin (A-7) is a compound represented by the following general formula (2-7). The resin (A-8) is a compound represented by the following general formula (2-8). The resin (A-10) is a compound represented by the following general formula (2-10). The resin (A-11) is a compound represented by the following general formula (2-11). The resin (A-12) is a compound represented by the following general formula (2-12).

(式(2-2)中，k-1為32，k-2為48，m為1，k-1、k-2、m之合計為81，n為19)。 (式(2-3)中，k-1為70，k-2為16，m為1，k-1、k-2、m之合計為87，n為13)。

(In formula (2-2), k-1 is 32, k-2 is 48, m is 1, the total of k-1, k-2, and m is 81, and n is 19). (In formula (2-3), k-1 is 70, k-2 is 16, m is 1, the total of k-1, k-2, and m is 87, and n is 13).

(式(2-4)中，k-1為52，k-2為34，m為3，k-1、k-2、m之合計為89，n為11)。 (式(2-5)中，k-1為11，k-2為52，m為4，k-1、k-2、m之合計為67，n為33)。

(In formula (2-4), k-1 is 52, k-2 is 34, m is 3, the total of k-1, k-2, and m is 89, and n is 11). (In formula (2-5), k-1 is 11, k-2 is 52, m is 4, the total of k-1, k-2, and m is 67, and n is 33).

(式(2-6)中，k-1為56，k-2為24，m為0.2，k-1、k-2、m之合計為80.2，n為19.8)。 (式(2-7)中，k-1為15，k-2為72，m為1，k-1、k-2、m之合計為88，n為12)。

(In formula (2-6), k-1 is 56, k-2 is 24, m is 0.2, the total of k-1, k-2, and m is 80.2, and n is 19.8). (In formula (2-7), k-1 is 15, k-2 is 72, m is 1, the total of k-1, k-2, and m is 88, and n is 12).

(式(2-8)中，k-1為37，k-2為44，m為2，k-1、k-2、m之合計為83，n’為17)。 (式(2-10)中，k-1為34，k-2為47，m為4，k-1、k-2、m之合計為85，n為15)。

(In formula (2-8), k-1 is 37, k-2 is 44, m is 2, the total of k-1, k-2, and m is 83, and n'is 17). (In formula (2-10), k-1 is 34, k-2 is 47, m is 4, the total of k-1, k-2, and m is 85, and n is 15).

(式(2-11)中，k為66，l為12，m為2，k、l、m之合計為80，n為20)。 (式(2-12)中，k為55，l為23，m為2，k、l、m之合計為80，n為20)。

(In formula (2-11), k is 66, l is 12, m is 2, the total of k, l, and m is 80, and n is 20). (In formula (2-12), k is 55, l is 23, m is 2, the total of k, l, and m is 80, and n is 20).

For the resins (A-2) to (A-8) and (A-10) to (A-12), the weight average molecular weight, glass transition temperature, and acid value were investigated in the same manner as the photosensitive resin (A-1). The results are shown in Table 3.

(Production Example 9) Except for using the carboxyl group-containing ethylenically unsaturated monomer (a), the ethylenically unsaturated monomer (d), and the polymerization initiator at the contents (parts by mass) shown in Table 2, the preparation of the first 1 Mixed solution.

In a four-necked flask equipped with a stirrer, a dropping funnel, a cooling tube, and a nitrogen introduction tube, 261.7 parts by mass of ethyl acetate as a solvent was fed, and heated to reflux. After heating under reflux, the first mixed solution described in Table 2 was added dropwise uniformly over 4 hours. After the dropwise addition, stirring was continued under heating under reflux for 6 hours. Subsequently, the reaction system was cooled to 60°C, 286.4 parts by mass of ethyl acetate as a solvent was added, and 100 parts by mass relative to the total of the carboxyl group-containing resin (b) and 2-isocyanatoethyl methacrylate (MOI) described later. 0.15 parts by mass of the polymerization inhibitor 4-methoxyphenol, 0.3 parts by mass with respect to the total 100 parts by mass of the carboxyl group-containing resin (b) and 2-isocyanatoethyl methacrylate (MOI) described later As a catalyst of dioctyl tin dilaurate.

After dissolving 4-methoxyphenol, 47.8 parts by mass of 2-isocyanatoethyl methacrylate (MOI) was added to the reaction system, stirring was continued at 60°C for 8 hours, and the synthetic resin (A-9) was cooled to room temperature. Temperature (23°C). The resin (A-9) is a compound represented by the general formula (2-9) by the same identification results as in Production Example 1. In the compound represented by the general formula (2-9), the repeating unit k of the formula (1-1) is two kinds of repeating units (k-1, k-2) different in R ⁵ .

(式(2-9)中，k-1為48，k-2為32，m為1，k-1、k-2、m之合計為81，j為2，n”為17)。

(In formula (2-9), k-1 is 48, k-2 is 32, m is 1, the total of k-1, k-2, and m is 81, j is 2, and n" is 17).

Regarding the resin (A-9), similar to the resin (A-1), the weight average molecular weight, glass transition temperature, and acid value were investigated. The results are shown in Table 3. In addition, for resins (A-1) to (A-12), the total of k-1, k-2, and k (k-1 and k-2 in each chemical formula (2-1) to (2-12) ), l, m, n, n', n" are shown in Table 3.

Tables 1 and 2 show the carboxyl group-containing ethylenically unsaturated monomer (a) used in the production of resins (A-1) to (A-12), and the ethylenic copolymerizable with the above (a) Unsaturated monomers (d), polymerization initiators, alicyclic epoxy-containing ethylenically unsaturated compounds (c), catalysts, polymerization inhibitors and solvents, types and amounts used (parts by mass), methyl The use amount (parts by mass) of glycidyl acrylate (GMA) and 2-isocyanatoethyl methacrylate (MOI).

[Examples 1 to 12, Comparative Examples 1 to 2] To the reaction solutions of the resins (A-1) to (A-12) synthesized in Production Examples 1 to 12, ethyl acetate as a solvent was added to adjust the content of each resin (A-1) to (A-12) 30% by mass. Using a resin (A-1) to (A-12) solution having a resin (A-1) to (A-12) content of 30% by mass, an adhesive composition was obtained by the method shown below.

Add the resin (A) and the photopolymerization initiator (B) shown in Table 4 to Table 6 to the contents (mass parts) shown in Table 4 to Table 6 in the plastic container inside the room where the active thread is blocked. ) And stirring with the crosslinking agent (C) to obtain the adhesive composition of Examples 1 to 12 and Comparative Examples 1 to 2. The numerical values of resins (A-1) to (A-12) in Tables 4 to 6 are resins (A-1) to (A-12) with a content of 30% by mass (A-1) to (A -12) The amount of solution used (parts by mass). The numerical value of the photopolymerization initiator (B) is the amount (parts by mass) of the photopolymerization initiator (B) relative to 100 parts by mass of the resin (A). The numerical value of the cross-linking agent (C) is the amount of use (parts by mass) of the cross-linking agent (C) with respect to 100 parts by mass of the resin (A).

"TETRAD-C", "HX", "TPO" in Tables 4 to 6, and "TETRAD-X" in Tables 4 and 5 are as shown below. "TETRAD-C" 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane (Mitsubishi Gas Chemical Co., Ltd., trade name: TETRAD-C) "TETRAD-X" N,N'-[1,3-Phenylbis(methylene)]bis[bis(oxysilan-2-ylmethyl)amine] (Mitsubishi Gas Chemical Co., Ltd., commodity Name: TETRAD-X) "HX" isocyanurate body of hexamethylene diisocyanate (manufactured by TOSOH Corporation, trade name: CORONATE (registered trademark) HX) "TPO" 2,4,6-trimethylbenzyl diphenylphosphine oxide (manufactured by BASF, trade name: L-TPO)

"Manufacture of Adhesive Sheets" The adhesive compositions of Examples 1 to 12 and Comparative Examples 1 to 2 were directly coated on the substrate so that the film thickness after drying became 20 μm, and were heated and dried at 100° C. for 2 minutes to form an adhesive layer. Subsequently, the adhesive sheets of Examples 1 to 12 and Comparative Examples 1 to 2 were obtained by sticking the release sheet on the adhesive layer. As the base material and the release sheet, a polyethylene terephthalate (PET) film with a thickness of 50 μm was used.

The adhesive sheets of Examples 1 to 12 and Comparative Examples 1 to 2 thus obtained were evaluated for the items shown below by the methods shown below. The results are shown in Table 4 to Table 6.

"Peel strength before UV irradiation" Cut the adhesive sheet to a length of 25mm and a width of 100mm, and peel off the peeling sheet to expose the adhesive layer. Next, the exposed adhesive layer (measurement surface) was in contact with the glass plate, the adhesive sheet was attached to the glass plate, and a two-kilogram rubber roller (width: about 50 mm) was reciprocated once to prepare a sample for measuring the peel strength before UV irradiation. The obtained measurement sample was placed in an environment with a temperature of 23° C. and a humidity of 50% for 24 hours. Subsequently, in accordance with JIS Z0237, a tensile test in the 180° direction was performed at a peeling speed of 300 mm/min, and the peeling strength (N/25 mm) of the adhesive sheet to the glass plate was measured.

"Peel strength after UV irradiation" It was prepared in the same way as the sample for measuring the peel strength before UV irradiation, and ultraviolet light (UV) was irradiated from the surface on the side where the sheet was adhered under the condition of an irradiation amount of 500 mJ/cm ^{2 to} make the measurement of the peel strength after UV irradiation sample. For the UV irradiation system, a conveyor belt type ultraviolet irradiation device (manufactured by Eye Graphics, 2KW lamp, 80W/cm) was used. The obtained measurement sample was measured for the peel strength (N/25mm) of the adhesive sheet to the glass plate in the same manner as the "peel strength before UV irradiation".

"Peel strength after heat-resistant UV irradiation" Prepared in the same way as the sample for measurement of peel strength before UV irradiation, after heat treatment maintained at 200°C for 2 hours, cooled to room temperature (23°C), irradiated with UV under the same conditions as "Peel strength after UV irradiation", and made heat resistant Sample for measurement of peel strength after UV irradiation. With respect to the obtained measurement sample, the peel strength (N/25 mm) of the adhesive sheet to the glass plate was measured in the same manner as the "peel strength after UV irradiation".

"Blurred" The glass plate after the measurement of the peeling strength after UV irradiation was visually observed and evaluated by the following criteria. The results are shown in Table 4 to Table 6. (Evaluation criteria) ○: No adhesive remains on the glass plate. △: Adhesive remained on a part of the glass plate. ×: Adhesive remained on the entire glass plate.

As shown in Table 4 and Table 5, the adhesive sheets of Examples 1 to 12 have a "peel strength before UV irradiation" of 1.0 N/25 mm or more, and a "peel strength after heat-resistant UV irradiation" of 2.5 N/25 mm or less. The evaluation was ○ or △. On the other hand, as shown in Table 6, the resin (A) does not contain the adhesive sheets of Comparative Examples 1 and 2 of the structure derived from an alicyclic compound. Although the "peel strength after UV irradiation" is sufficiently low, the " The “peel strength after heat-resistant UV irradiation” was high, and the residue evaluation was ×.

Claims (7)

An adhesive composition characterized by comprising a resin (A) represented by the following general formula (1-1) and a photopolymerization initiator (B),

(In formula (1-1), k, l, m, and n represent the molar composition ratio when k+l+m+n=100, k is more than 0 to 92 or less, l is 0 to 50, and m is More than 0 to 90 or less, the total of k, l, and m is 65 to 95, n is 5 to 35, R ¹ to R ⁴ are -H or -CH ₃ , R ⁵ is an alkyl group having 1 to 16 carbon atoms, R ⁶ is an alicyclic hydrocarbon group having 3 to 30 carbon atoms or an aromatic hydrocarbon group having 6 to 20 carbon atoms, R ⁷ is -H or -(CH ₂ ) _j -COOH (where j is 1 or 2), and R ⁸ is In the above general formula (1-2) or (1-3), in formulas (1-2) and (1-3), p and q are selected from any one of 0, 1 and 2, when p is 0 s is 0, s is 1 when p is 1 or 2, and R ⁹ is -H or -CH ₃ ). The adhesive composition according to claim 1, wherein the weight average molecular weight of the resin (A) is 200,000 to 1,000,000. The adhesive composition according to claim 1 or 2, wherein n in the aforementioned formula (1-1) is 10 to 33. The adhesive composition according to any one of claims 1 to 3, wherein k in the aforementioned formula (1-1) is 45 to 90, l is 4 to 40, and m is 1 to 15. The adhesive composition according to any one of claims 1 to 4, which further contains a crosslinking agent (C). The adhesive composition according to any one of claims 1 to 5, wherein the glass transition temperature of the resin (A) is -80°C to 0°C. An adhesive sheet characterized by having a sheet-shaped substrate and an adhesive layer formed on the substrate, the adhesive layer comprising the adhesive composition according to any one of claims 1 to 6.