TWI779208B - 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 in Japan on September 3, 2018, the content of which is incorporated herein.

Conventionally, various adhesive sheets have been used in semiconductor manufacturing steps and the like. Specifically, there are protective sheets used to protect the wafer in the back grinding (back grind) process of the semiconductor wafer, and those used in the dicing process for cutting the semiconductor wafer into small pieces. Sheets for fixing, etc. These adhesive sheets are re-peelable adhesive sheets that are attached to the semiconductor wafer of the adherend and peeled off from the adherend after specific processing steps are completed. As an adhesive composition used in the adhesive layer of a re-peelable adhesive sheet, one containing a UV (ultraviolet) curable resin having an ethylenically unsaturated group in the molecule is known.

Patent Document 1 discloses a method for producing an adhesive sheet, which includes 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 a compound having an amine group. The step of (meth)acrylic polymer having a formate bond, and making the (meth)acrylic polymer having a urethane bond and a compound having two or more isocyanate groups in one molecule 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 Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent No. 5996985

[Problem to be solved by the invention]

The re-peelable adhesive sheet is required to have sufficient adhesion to the adherend when performing a specific processing step, and can be easily peeled off from the adherend after the specific processing step is completed (easily peelable), and the adhesive that sticks the sheet after peeling The layer will not transfer to the adherend (no residue). However, conventional adhesive sheets do not fully satisfy the above-mentioned 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 peeled off by irradiating UV, it is easy to cause a problem of sticking.

The present invention was made in view of the above circumstances, and it is an object to provide an adhesive composition that can obtain sufficient adhesive force to an adherend even when the adhesive sheet is attached to the adherend by using it as a material for forming an adhesive layer of an adhesive sheet. After the body is returned to room temperature at high temperature, it can be peeled off after being irradiated with UV. It can also obtain excellent easy peelability, and at the same time, it is not easy to produce a sticky sheet with residue. Moreover, the subject of this invention is providing the adhesive sheet which has the adhesive layer which consists of the said adhesive composition. [Means to solve the problem]

The inventors of the present invention have repeated positive examinations in order to solve the above-mentioned problems. As a result, it was found that it is only necessary to use an 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 alicyclic epoxy group-containing ethylenically unsaturated compound (c) 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 cured by irradiating ultraviolet rays (UV) to form a three-dimensional crosslinked structure in unsaturated bonds in the resin (A), thereby changing the adhesive force. Specifically, before irradiating UV to the adhesive composition, sufficient adhesion to the adherend is obtained, and after UV irradiation, the adhesive force is reduced to obtain excellent peelability, and at the same time, it can fully prevent residue on the adherend after peeling off. The present inventors 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, n represent the molar composition ratio when k+l+m+n=100, k is more than 0-92, l is 0-50, m is More than 0 to less than 90, 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 with 1 to 16 carbons, R ⁶ is an alicyclic hydrocarbon group with 3 to 30 carbons or an aromatic hydrocarbon group with 6 to 20 carbons, R ⁷ is -H or -(CH ₂ ) _j -COOH (where j is 1 or 2), R ⁸ is Above general formula (1-2) or (1-3), in formula (1-2) and (1-3), p and q are selected from any one of 0, 1, 2, when p is 0 s is 0, and when p is 1 or 2, s is 1, and R ⁹ is -H or -CH ₃ ).

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

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

[7] 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 [1] to [6]. [Invention effect]

The adhesive composition of the present invention is used as a material for forming the adhesive layer of the adhesive sheet, so that sufficient adhesion to the adherend can be obtained, even if the adherend to which the adhesive sheet is attached returns to room temperature after being in a high temperature state, Peeling after UV irradiation can also obtain excellent peelability, and at the same time, it is not easy to produce an adhesive sheet with residual paste.

Hereinafter, the adhesive composition and the adhesive sheet of the present invention will be described in detail. In addition, this invention is not limited only to the embodiment shown below. [Adhesive composition] The adhesive composition of this embodiment contains 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, n represent the molar composition ratio when k+l+m+n=100, k is more than 0-92, l is 0-50, m is More than 0 to less than 90, 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 with 1 to 16 carbons, R ⁶ is an alicyclic hydrocarbon group with 3 to 30 carbons or an aromatic hydrocarbon group with 6 to 20 carbons, R ⁷ is -H or -(CH ₂ ) _j -COOH (where j is 1 or 2), R ⁸ is Above general formula (1-2) or (1-3), in formula (1-2) and (1-3), p and q are selected from any one of 0, 1, 2, when p is 0 s is 0, and when p is 1 or 2, s is 1, 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. k is more than 0 to less than 92. l is 0-50. m is more than 0 to less than 90. The total of k, l, m is 65-95. When the total of k, l, and m is 65 or more, it becomes an adhesive composition that obtains sufficient adhesiveness to the adherend before UV irradiation. The total of k, l, and m is preferably from 70 to 94, more preferably from 80 to 90.

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

In formula (1-1), the repeating unit represented by () in parentheses (hereinafter referred to as "repeating unit 1") may not be present. In other words, the repeating number of the repeating unit 1 may be zero. 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, more preferably 5-30.

In formula (1-1), the repeating unit represented by () in m brackets (hereinafter referred to as "repeating unit m") is an essential repeating unit. The repeating unit m contributes to the adhesion and heat resistance of the adhesive composition before UV irradiation. And when the adhesive composition contains a cross-linking agent having a functional group reacting with a carboxyl group, the repeating unit m can react with the cross-linking agent to improve the cohesion of the adhesive composition. The repeating number m of the repeating unit m is more than 0 to at most 90, preferably 1 to 15, more preferably 1 to 5.

In formula (1-1), the repeating unit represented by () in n brackets (hereinafter referred to as "repeating unit n") is an essential 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 5-35, preferably 10-33, more preferably 10-20. When the repeating unit n is 35 or less, the unsaturated bonds in the resin (A) are hardened by UV irradiation to form a three-dimensional cross-linked structure, and the adhesive force is reduced to an appropriate range to become an adhesive composition. Moreover, when n is 5 or more, the heat resistance improvement effect originating in the structure originating in an alicyclic compound is acquired.

The synergistic effect of the functions provided by these repeating units makes the adhesive composition containing the resin (A) better in balance between the adhesive force before ultraviolet (UV) irradiation and the adhesive force after UV irradiation. As a result, sufficient adhesive force to the adherend is obtained before UV irradiation, and the adhesive force decreases after UV irradiation to obtain more excellent peelability. Moreover, even if the adhesive composition returns from a high temperature state to room temperature before UV irradiation, the adhesive force will not become too high, and excellent peelability is obtained after UV irradiation, and it is not easy to cause damage to the adhesive after peeling off. The residue of the sticky body.

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

The repeating unit k may be a plurality of repeating units in which R ¹ and R ⁵ are different. When the repeating unit k includes a plurality of repeating units, the molar composition ratio k of the repeating unit k represents the sum of the molar composition ratios of the plural repeating units. For example, repeating unit k comprises R1 and/or R5 different repeating units ^A and B, when the molar composition ratio of repeating unit A is ² mol%, and the molar composition ratio of repeating unit B is 3 mol%, repeat The molar composition ratio k of the number k is "5" as the sum of the molar composition ratios of the repeating unit A and the repeating unit B.

In repeating unit 1, R ² is -H or -CH ₃ , preferably -H. R ⁶ is an alicyclic hydrocarbon group with 3 to 30 carbons or an aromatic hydrocarbon group with 6 to 20 carbons, preferably an alicyclic hydrocarbon group with 6 to 20 carbons or an aromatic hydrocarbon group with 6 to 10 carbons. Repeating unit 1 may also be a plurality of repeating units in which R ² and R ⁶ are different. When the repeating unit 1 includes a plurality of repeating units, the molar composition ratio 1 of the repeating unit 1 represents the sum 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 be plural repeating units in which R ³ and R ⁷ are different. In this case, the molar composition ratio m of the repeating unit m represents the total of the molar composition ratios of a plurality of 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 contain structures derived from alicyclic compounds, and have the function of improving the heat resistance of the adhesive composition. In formula (1-2) or (1-3), p and q are any one selected from 0, 1, and 2. s is 0 when p is 0, and s is 1 when p is 1 or 2. R ⁹ is -H or -CH ₃ . The repeating unit n may be a plurality of repeating units in which R ⁴ and R ⁸ are different. In this case, the molar composition ratio n of the repeating unit n represents the total of the molar composition ratios of a plurality of repeating units.

Resin (A) represented by formula (1-1) can be any of random copolymer, block copolymer and alternating copolymer formed by repeating unit k, repeating unit l, repeating unit m and repeating unit n By. The resin (A) represented by the formula (1-1) may also not contain the repeating unit l, and may be a random copolymer, a block copolymer, or an alternating copolymer formed of repeating unit k, repeating unit m, and repeating unit n. either.

The weight average molecular weight of the resin (A) is preferably from 200,000 to 1 million, more preferably from 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 then peeled off, the adhesive layer is less likely to remain on 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 will be obtained. The weight average molecular weight of resin (A) is the value measured according to the method described in an Example.

The glass transition temperature (Tg) of the resin (A) is preferably from -80 to 0°C, more preferably from -60 to 10°C, still more preferably from -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 resin (A) is the value measured according to the method described in an Example. The acid value of the resin (A) is preferably more than 0-20 mgKOH/g, more preferably 3-10 mgKOH/g. When the acid value of the resin (A) exceeds the range of 0 to 20 mgKOH/g, there is no contamination (residue) with adherends after heating, which is good. Furthermore, when the adhesive composition contains a cross-linking agent, if the acid value of the resin (A) is within the above range, the resin (A) and the cross-linking agent will react to improve the cohesion 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 manufactured by the method shown below, for example. First, the raw material monomer containing the carboxyl group-containing ethylenically unsaturated monomer (a) and the ethylenically unsaturated monomer (d) is polymerized to produce the carboxyl group-containing resin (b). Here, the ethylenically unsaturated monomer (d) may include a monomer that forms a repeating unit k after polymerization, or may include a monomer that forms a skeleton of a repeating unit l. Next, resin (A) is manufactured by making addition reaction of carboxyl group-containing resin (b) and the ethylenic unsaturated compound (c) containing a specific alicyclic epoxy group.

(Carboxyl-containing ethylenically unsaturated monomer (a)) The carboxyl group-containing ethylenically unsaturated monomer (a) used for producing the carboxyl group-containing resin (b) is a monomer that 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, β-carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, and the like. Among them, as the carboxyl group-containing ethylenically unsaturated monomer (a), it is preferable to use (meth)acrylic acid and/or β-carboxyethyl (meth)acrylate from the viewpoint of reactivity.

In this specification, (meth)acryl means "acryl" or "methacryl". The so-called (meth)acrylate means "acrylate" or "methacrylate".

(Carboxyl-containing resin (b)) The carboxyl group-containing resin (b) is a product comprising at least carboxyl group-containing ethylenically unsaturated monomer (a) and carboxyl group-containing ethylenically unsaturated monomer (a) copolymerizable ethylenically unsaturated monomer (d). Raw material monomer copolymerizer. The carboxyl group-containing resin (b) is a component that becomes the skeleton of the resin (A) represented by the formula (1-1). The repeating unit k, the repeating unit 1, and the 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 that 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 k by polymerization may be used together with one or more monomers that form the skeleton of the repeating unit l by polymerization.

The ethylenically unsaturated monomer (d) that forms the skeleton of the repeating unit k by polymerization is an alkyl ester of (meth)acrylic acid having 1 to 16 carbon atoms. From the viewpoint of adjusting the peel strength of the adhesive composition, it is preferable to It preferably includes an alkyl ester of (meth)acrylic acid having 2 to 16 carbon atoms, more preferably includes an alkyl ester of (meth)acrylic acid having 4 to 12 carbon atoms. Specifically, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, Isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, n-hexyl (meth)acrylate, isooctyl (meth)acrylate, (meth)acrylate ) lauryl acrylate, etc. Among these, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, iso(meth)acrylate Octyl esters.

As the ethylenically unsaturated monomer (d) which forms the skeleton of the repeating unit 1 by polymerization, there are, for example, (meth)acrylates containing a cyclic alkyl group having 3 to 30 carbons, and (meth)acrylates containing 6 to 20 carbons. Aromatic (meth)acrylate, etc.

Examples of (meth)acrylic acid esters containing a cyclic alkyl group having 3 to 30 carbon atoms used as the ethylenically unsaturated monomer (d) that forms the skeleton of the repeating unit 1 by polymerization include, for example, (meth)acrylic acid Cyclohexyl, Norbornyl (meth)acrylate, Isobornyl (meth)acrylate, Norbornenyl (meth)acrylate, Dicyclopentenyl (meth)acrylate, Bicyclo(meth)acrylate Pentenyloxyethyl ester, dicyclopentyl (meth)acrylate, dicyclopentyloxyethyl (meth)acrylate, tricyclodecane dimethylol di(meth)acrylate, and the like. 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 heat resistance of the adhesive composition containing the resin (A) produced using the carboxyl group-containing resin (b) is good.

Examples of (meth)acrylic acid esters containing an aromatic group having 6 to 20 carbon atoms used as the ethylenically unsaturated monomer (d) that forms the skeleton of the repeating unit 1 by polymerization include, 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 heat resistance of the adhesive composition containing the resin (A) produced using the carboxyl group-containing resin (b) is good .

The raw material monomer of the carboxyl group-containing resin (b) may contain not only the above-mentioned carboxyl group-containing ethylenically unsaturated monomer (a) and the above-mentioned ethylenically unsaturated monomer (d), but also the above-mentioned ethylenically unsaturated monomer A monomer other than (d) that can be copolymerized with the carboxyl group-containing ethylenically unsaturated monomer (a).

Examples of ethylenically unsaturated monomers that can be copolymerized with the carboxyl group-containing ethylenically unsaturated monomer (a) other than the above-mentioned ethylenically unsaturated monomer (d) include alkoxyalkyl (meth)acrylate, alkyl Oxy(poly)alkylene glycol (meth)acrylate, hydroxyl-containing (meth)acrylate, fluorinated alkyl (meth)acrylate, dialkylaminoalkyl (meth)acrylate, (meth) ) acrylamide, etc.

Examples of alkoxyalkyl (meth)acrylates include ethoxyethyl (meth)acrylate, methoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, (meth) ) 2-methoxyethoxyethyl acrylate, 2-ethoxyethoxyethyl (meth)acrylate, etc.

Examples of alkoxy (poly) alkylene glycol (meth)acrylates include, for example, methoxydiethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, (methyl) ) Methoxydipropylene glycol acrylate, etc.

Examples of hydroxyl-containing (meth)acrylates include 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 Esters etc.

Examples of the fluorinated alkyl (meth)acrylate 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, N-propyl(methyl) ) acrylamide, N-isopropylacrylamide, N-hexyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(methyl)acrylamide ) acrylamide, (meth)acryl morpholine, diacetone acrylamide, etc.

Specific examples of monomers other than the ethylenically unsaturated monomer (d) that can be copolymerized with the carboxyl group-containing ethylenically unsaturated monomer (a) other than those mentioned above include acrylonitrile, methacrylonitrile, styrene, α-Methylstyrene, Vinyl Acetate, Vinyl Propionate, Vinyl Stearate, Vinyl Chloride, Vinylidene Chloride, Alkyl Vinyl Ether, Vinyl Toluene, N-Vinyl Pyridine, N-Vinyl Pyrrole 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, allyltrimethylammonium chloride, dimethylallyl vinyl ketone, and the like.

The method for producing the carboxyl group-containing resin (b) is not particularly limited. For example, raw material monomers including the carboxyl group-containing ethylenically unsaturated monomer (a) and the ethylenically unsaturated monomer (d) which are constituents of the carboxyl group-containing resin (b) can be copolymerized by a known polymerization method And get. Specifically, as a polymerization method, a solution polymerization method, an emulsion polymerization method, a mass polymerization method, a suspension polymerization method, an alternating copolymerization method, and the like can be used. In these polymerization methods, when considering the addition reaction between the carboxyl group-containing resin (b) obtained after polymerization and the alicyclic epoxy group-containing ethylenically unsaturated compound (c), from the viewpoint of ease of reaction, it is more difficult to It is best to use solution polymerization.

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 from among those skilled in the art. Examples of radical polymerization initiators include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2 ,2'-Azobis(2,4-dimethylvaleronitrile), 2,2'-Azobis(2-methylbutyronitrile), 1,1'-Azobis(cyclohexane-1 Azo-based polymerization of -formonitrile), 2,2'-azobis(2,4,4-trimethylpentane), 2,2'-azobis(2-methylpropionate), etc. Initiator; benzoyl peroxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, tert-butyl peroxybenzoate, dicumyl peroxide, 1,1 - Peroxides such as bis(tert-butylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis(tert-butylperoxy)cyclododecane, etc. Oil-soluble polymerization initiators such as initiators.

These radical polymerization initiators may 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 still more preferably 0.03 to 3 parts by mass.

As the polymerization solvent used in the production of the carboxyl group-containing resin (b), various general solvents can be used. Examples of solvents 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 of ketone, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, etc.; glycol esters of ethylene glycol diacetate, propylene glycol monomethyl ether acetate, etc. These solvents may be used alone or in combination of two or more.

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

(Ethylenically unsaturated compound (c) containing alicyclic epoxy group) The ethylenically unsaturated compound (c) containing an alicyclic epoxy group is an ethylenically unsaturated compound having an alicyclic epoxy group, which can be given by general formula (1-2) or general formula (1-3) The compound of the structure. The alicyclic epoxy group in this embodiment refers to 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 alicyclic epoxy group is for the following partial structural formula (1-2) in the repeating unit n of the photosensitive resin (A) shown in addition formula (1-1) ') or (1-3'). The partial structural formula (1-2') or (1-3') in the repeating unit n in the formula (1-1) is derived from the base of the ethylenically unsaturated compound (c) containing 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 alicyclic epoxy group-containing ethylenically unsaturated compound (c) is preferably a compound represented by formula (1), and it is particularly preferable to use 3,4-epoxycyclohexylmethyl (meth)acrylate. The alicyclic epoxy group-containing ethylenically unsaturated compound (c) may be used alone or in combination of two or more.

The resin (A) of this embodiment can be added by adding the alicyclic epoxy group of the alicyclic epoxy group-containing ethylenically unsaturated monomer (c) to the carboxyl group of the carboxyl group-containing resin (b) And manufacture. Resin (A) is preferably 0.2-0.99 mol, more preferably 0.3-0.95 mol, and more preferably 0.6-0.95 mol of alicyclic epoxy group-containing 1 mol of carboxyl group-containing resin (b). Ethylenically unsaturated compound (c) and manufacture. An adhesive composition comprising a carboxyl group-containing resin (b) and an alicyclic epoxy group-containing ethylenically unsaturated compound (c) using the obtained resin (A) in the above ratio, obtains an adhesive composition to the adherend before UV irradiation. Sufficient adhesiveness, the adhesive force decreases after UV irradiation to obtain better 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 easy to become high, and excellent peelability is obtained after UV irradiation, and it can more effectively prevent damage to the substrate after peeling off. The residue of the sticky body.

The temperature of the addition reaction when producing the resin (A) is preferably from 80 to 130°C, particularly preferably from 90 to 120°C. If the addition reaction temperature is 80° C. or higher, a sufficient reaction rate will be obtained. When the addition reaction temperature is 130° C. or lower, it is possible to prevent the double bond portion from being crosslinked by thermal radical polymerization to produce a gelled product.

In the addition reaction at the time of producing resin (A), a known catalyst can be used as needed. Examples of catalysts include triethylamine, tributylamine, dimethylbenzylamine, 1,8-diazabicyclo[5,4,0]undec-7-ene, 1,5-diazepine Tertiary amines such as heterobicyclo[4,3,0]non-5-ene, 1,4-diazabicyclo[2,2,2]octane; tetramethylammonium chloride, tetramethyl bromide Quaternary 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-dimethyl Phosphine compounds such as oxyphenyl)phosphine, tris(2,4,6-trimethylphenyl)phosphine and tris(2,4,6-trimethoxyphenyl)phosphine, etc. As a catalyst for the addition reaction, among the above, a phosphine compound is preferably used from the viewpoint of reactivity.

The amount of the 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.

Furthermore, during the addition reaction, a gas having a polymerization inhibitory effect may also be introduced into the reaction system, and a polymerization inhibitor may also be added. By introducing a gas with polymerization inhibitory effect into the reaction system or adding a polymerization inhibitor, gelation during the addition reaction can be prevented. Examples of the gas having a polymerization inhibitory effect include gas containing oxygen to such an extent that the substances in the system do not explode, such as air.

Known ones can be used as polymerization inhibitors without particular limitation, but for example, 4-methoxyphenol, hydroquinone, methoxyphenol, 2,6-di-tert-butylphenol, 2,2 '-methylenebis(4-methyl-6-tert-butylphenol), phenothiazine, etc. These polymerization inhibitors may be used alone or in combination of two or more.

The amount of the polymerization inhibitor used is preferably 0.005 to 5 parts by mass, more preferably Preferably it is 0.03 to 3 parts by mass, more 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, when the amount of polymerization inhibitor is too large, the exposure sensitivity of resin (A) may fall. Also, when a gas having a polymerization inhibitory effect is used in combination with a polymerization inhibitor, it is preferable because the amount of the polymerization inhibitor used can be reduced and the polymerization inhibitory effect can be increased.

(Photopolymerization initiator (B)) Examples of the photopolymerization initiator (B) contained in the adhesive composition include 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, benzoin methyl ether, benzophenone Isobutyl ether, benzoin n-butyl ether, benzyl methyl acetal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-(4-Isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, methyl benzoylformate, 2,2-diethoxyacetophenone, 4-N, Carbonyl-based photopolymerization initiators such as N'-dimethylacetophenone and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one.

As the photopolymerization initiator (B), thioether-based photopolymerization agents such as diphenyl disulfide, dibenzyl disulfide, tetraethylthiuram disulfide, and tetramethylammonium monosulfide can also be used. Initiator; Acylphosphine such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide Oxides; quinone-based photopolymerization initiators such as benzoquinone and anthraquinone; sulfonyl chloride-based photopolymerization initiators; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, etc. Department of photopolymerization initiator, etc.

Among these photopolymerization initiators (B), it is preferable to use 1-hydroxycyclohexyl phenyl ketone and/or 2,4,6-trimethylbenzoyl from the viewpoint of solubility in the adhesive composition. diphenylphosphine oxide. The said photoinitiator (B) may be used individually, and may use 2 or more types together.

The photoinitiator (B) contained in an adhesive composition is preferably 0.1-5.0 mass parts with respect to 100 mass parts of resin (A), More preferably, it is 0.5-2.0 mass parts. When the content of the photopolymerization initiator (B) is 0.1 part by mass or more relative to 100 parts by mass of the resin (A), the adhesive composition is cured at a sufficiently fast curing rate by UV irradiation, and after UV irradiation It is preferable that the adhesive force of the adhesive composition is sufficiently reduced. When the content of the photopolymerization initiator (B) is 5.0 parts by mass or less, the adhesive sheet having the adhesive layer containing the adhesive composition will not easily remain on the adherend when the adhesive sheet is attached to the adherend and then peeled off. . Moreover, even if content of a photoinitiator (B) exceeds 5.0 mass parts, the effect corresponding to content of a photoinitiator (B) was not seen.

(Crosslinking agent (C)) The adhesive composition of this embodiment may contain not only a resin (A) and a photopolymerization initiator (B), but also a crosslinking agent (C). By containing a crosslinking agent (C), it becomes an adhesive composition with a better balance of the adhesive force before UV irradiation, and the adhesive force after UV irradiation. The crosslinking agent (C) is not particularly limited, but is preferably a compound having two or more functional groups reactive to 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, tetramethylxylene diisocyanate, 1,5-naphthalene diisocyanate, toluene diisocyanate adduct of trimethylolpropane , Xylene diisocyanate adduct of trimethylolpropane, triphenylmethane triisocyanate, methylene bis(4-phenylmethane) triisocyanate and other isocyanate compounds; Bisphenol A・epichlorohydrin type epoxy resin, N,N'-[1,3-phenylenebis(methylene)]bis[bis(oxysilane-2-ylmethyl)amine], ethyl Glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin 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-acridinylpropionate, Trimethylolmethane-tri-β-acridinylpropionate, N,N'-diphenylmethane-4,4'-bis Acridine compounds such as (1-acridylcarboxamide), N,N'-hexamethylene-1,6-bis(1-acridylcarboxamide); Hexamethoxymethyl melamine, hexaethoxymethyl melamine, hexapropoxymethyl melamine, hexapropoxymethyl melamine, hexapentyloxymethyl melamine, hexahexyloxymethyl melamine, etc. compounds etc.

Among them, as the crosslinking agent (C), epoxy-based compounds and/or isocyanate-based compounds are preferably used because they have good reactivity with the resin (A). The said crosslinking agent (C) may be used individually or in combination of 2 or more types.

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

(other ingredients) The adhesive composition of this embodiment may contain other components other than the said resin (A), photoinitiator (B), and crosslinking agent (C) as needed. Examples of other components include tackifiers, solvents, and various additives.

(adhesion imparting agent) As the tackifier, conventionally known ones can be used without particular limitation. Examples of tackifiers include terpene-based tackifier resins, phenolic tackifier resins, rosin-based tackifier resins, aliphatic petroleum resins, aromatic petroleum resins, copolymerized petroleum resins, and alicyclic petroleum resins. , xylene resin, epoxy-based adhesion-imparting resin, polyamide-based adhesion-imparting resin, ketone-based adhesion-imparting resin, elastic-based adhesion-imparting resin, etc. These tackifiers may be used alone or in combination of two or more.

When the adhesive composition of the present embodiment contains the tackifier, the content thereof is preferably at most 30 parts by mass, more preferably from 5 to 20 parts by mass, based on 100 parts by mass of the resin (A).

(solvent) The solvent is used to dilute the adhesive composition for the purpose of adjusting the viscosity of the adhesive composition when coating the adhesive composition. Solvents such as methyl ethyl ketone, methyl isobutyl ketone, acetone, ethyl acetate, n-propyl acetate, tetrahydrofuran, dioxane, cyclohexanone, n-hexane, toluene, xylene, n-propanol can be used , isopropanol 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, antiaging agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, benzotriazole-based light stabilizers, phosphoric acid, etc. Esters and other flame retardants, surfactant-like antistatic agents, etc.

[Manufacturing method of adhesive composition] The adhesive composition of this embodiment can be manufactured by conventional methods. For example, it can be produced by mixing and stirring the above-mentioned resin (A), a photopolymerization initiator (B), and optionally a crosslinking agent (C), an adhesion imparting agent, a solvent, and various additives using conventionally known methods.

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

[adhesive sheet] The adhesive sheet of the present invention has a sheet-shaped substrate and an adhesive layer formed on the substrate. A release sheet (separator) is preferably provided on the surface of the adhesive layer opposite to the substrate. When the peeling sheet is provided on the adhesive layer, the adhesive layer can be protected until use by the peeling sheet. Also, when the release sheet is provided on the adhesive layer, the operation of peeling the release sheet to expose the adhesive layer and pressing the adhesive layer (adhesion surface) to the adherend can be efficiently performed. The adhesive sheet of this embodiment can also be used as an adhesive tape formed into a shape corresponding to the shape of an adherend by a punching method or the like. Moreover, the adhesive sheet of this embodiment can also be used as an adhesive tape by winding up and cutting.

As the substrate, known 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 polyethylene (PE), polypropylene (PP) and other polyolefins; polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polynaphthalate Polyester sheets 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. A resin material may be used individually by 1 type, and may mix and use 2 or more types.

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

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

When a resin sheet is used as the base material, the base material can be manufactured by using conventionally known general sheet forming methods (such as extrusion molding, T-die molding, blow molding, etc., or uniaxial or biaxial stretching molding, etc.).

The surface of the base material on the side in contact with the adhesive layer may be subjected to surface treatment for improving the adhesion between the base material and the adhesive layer. As the surface treatment, for example, corona discharge treatment, acid treatment, ultraviolet irradiation treatment, plasma treatment, primer coating and the like are exemplified.

The adhesive layer of the adhesive sheet of this embodiment contains the above-mentioned adhesive composition. The thickness of the adhesive layer is preferably from 1 to 100 μm, more preferably from 2 to 80 μm, and more preferably from 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 the adhesive layer is formed using a solvent, since the solvent can also be easily removed, it is preferable.

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

The release surface of the release sheet (the surface arranged in contact with the adhesive layer) can also be subjected to release treatment using conventionally known release agents such as silicone-based, long-chain alkyl-based, fluorine-based, etc. as needed.

[Manufacturing method of adhesive sheet] The adhesive sheet of this embodiment can be manufactured by the method shown below, for example. First, an adhesive solution in which the above-mentioned adhesive composition is dissolved or dispersed in a solvent is produced. The above-mentioned adhesive composition can be directly used as an adhesive solution. Secondly, the adhesive solution is coated on the substrate, heated and dried to form an adhesive layer. Then, on the adhesive layer, if necessary, the peeling sheet is bonded and obtained. Moreover, as another method of manufacturing the adhesive sheet of this embodiment, the said adhesive agent solution is apply|coated on the peeling sheet, and it heats and dries, and forms an adhesive agent layer, for example. Subsequently, a peeling sheet with an adhesive layer is placed on the substrate with the side of the adhesive layer facing the substrate, and the adhesive layer is transferred (moved to stick) on the substrate.

Conventional methods can be used for the method of coating the above-mentioned adhesive solution on the substrate (or on the release sheet). Specifically, there are exemplified the use of a conventional coater such as a gravure roll coater, reverse roll coater, touch roll coater, dip roll coater, bar coater, knife coater, spray coater, etc. Coating methods such as chip coater, notched wheel coater, direct roll coater, etc.

[Application 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. Specifically, the adhesive sheet of this embodiment is used for fixing the adherend in each step of manufacturing electronic parts, delivering it to various processing steps, irradiating it with ultraviolet rays (UV), peeling the adherend and recycling it. Therefore, the adhesive sheet of this embodiment can be used as back grinding tape, dicing tape, etc. during semiconductor wafer processing. In addition, the adhesive sheet of this embodiment can be preferably used as support tapes for fragile members such as ultra-thin glass substrates, plastic films, and easily warped members such as flexible printed circuit boards (FPC boards). In particular, the adhesive sheet of this embodiment can be preferably used as a dicing tape for protecting a wafer during a dicing step of the wafer.

When the adhesive sheet of this embodiment is used as a wafer dicing tape, the adhesive sheet is attached to the wafer on which a plurality of components are formed before the dicing step. Next, the wafer is cut off, diced (cut) into individual parts, and becomes component chips (wafers). Subsequently, UV is irradiated to the adhesive sheet attached to each element die. In this way, UV is irradiated to the adhesive layer through the base material of the adhesive sheet, so that the unsaturated bonds in the adhesive form a three-dimensional cross-linked structure and harden. As a result, the adhesive force of the adhesive layer is lowered. Subsequently, the adhesive sheet is peeled off from each component chip.

Examples of light sources used for UV irradiation of the adhesive sheet attached to the adherend before peeling off include high-pressure mercury lamps, ultra-high pressure mercury lamps, carbon arc lamps, xenon lamps, metal halide lamps, chemical lamps, and black lights. The amount of UV irradiation to the adhesive sheet is preferably from 50 to 3000 mJ/cm ² , more preferably from 100 to 600 mJ/cm ² . When the amount of UV irradiation to the adhesive sheet is 50mJ/cm ² or more, the adhesive layer can be cured at a sufficiently fast curing speed by UV irradiation, and the adhesive force of the adhesive layer after UV irradiation is sufficiently reduced, which is preferable. Even if the amount of UV irradiation applied to the adhesive sheet is 3000 mJ/cm ² or more, the corresponding effect cannot be obtained. [Example]

Hereinafter, the present invention will be further specifically described by way of examples and comparative examples. In addition, this invention is not limited only to the following Examples.

[Manufacture of resin (A)] (Manufacturing example 1) [Preparation of the first mixed solution] As shown in Table 1, the first mixed solution was prepared, which contained 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). ) of 71.8 parts by mass of n-butyl acrylate and 143.6 parts by mass of 2-ethylhexyl acrylate as raw material monomers and 0.1 parts by mass relative to the total of 100 parts by mass of raw material monomers of carboxyl group-containing resin (b) 2,2'-Azobisisobutyronitrile as starter.

[Preparation of the second mixed solution] As shown in Table 1, the second mixed solution was prepared, which contained 59.8 parts by mass of 3,4-epoxycyclohexylmethyl methacrylate and the relative Tris (4-methylphenyl) phosphine ( TPTP) and 100.0 parts by mass of n-butyl acetate and 91.1 parts by mass of toluene as a solvent.

175.6 parts by mass of n-butyl acetate as a solvent was fed into a four-necked flask equipped with a stirrer, a dropping funnel, a cooling pipe, and a nitrogen gas introduction pipe, and the temperature was raised to 80° C. under a nitrogen atmosphere. Next, while keeping the reaction temperature at 80°C±2°C, spend 4 hours to uniformly add the above-mentioned first mixed solution in the above-mentioned four-necked flask, and after the dropwise addition, continue stirring at a temperature of 80°C±2°C for 6 hours. Hours, the carboxyl group-containing resin (b) is polymerized. Then, in the reaction system, 0.15 parts by mass of 100 parts by mass of the total of 100 parts by mass of the carboxyl group-containing resin (b) and the alicyclic epoxy group-containing ethylenically unsaturated monomer (c) was added as a polymerization inhibitor. 4-Methoxyphenol.

Heat the reaction system to which 4-methoxyphenol was added to 100°C, add the above-mentioned second mixed solution dropwise over 0.5 hours, continue stirring at 100°C for 8 hours, synthesize resin (A-1), and cool to room temperature temperature (23°C). Resin (A-1) was identified by the nuclear magnetic resonance method (NMR method), and it 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) with different 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).

About resin (A-1), weight average molecular weight and glass transition temperature were investigated by the method shown below. In addition, the acid value of resin (A-1) is measured based on JISK0070. The results are shown in Table 3.

＜Weight average molecular weight (Mw)＞ Using a gel permeation chromatography (manufactured by Showa Denko Co., Ltd., Shodex (registered trademark) GPC-101), it measured at normal temperature under the following conditions, and calculated in terms of polystyrene. String: Showa Denko Co., Ltd., Shodex (registered trademark) LF-804 Column temperature: 40°C Sample: 0.2% by mass tetrahydrofuran solution of resin (A) Flow rate: 1ml/min Eluent: Tetrahydrofuran Detector: RI detector

＜Glass transition temperature (Tg)＞ A 10 mg sample was collected from the resin (A). Use a differential scanning calorimeter (DSC) to change the temperature of the sample from -100°C to 200°C at a heating rate of 10°C/min to perform differential scanning calorimetry. The endothermic start temperature caused by the observed glass transition is taken as Tg. Moreover, when two Tgs were observed, it was set as the simple average value of two Tgs.

(Manufacturing examples 2-8, 10-12) Except for using the carboxyl group-containing ethylenically unsaturated monomer (a), ethylenically unsaturated monomer (d) and polymerization initiator at the contents (parts by mass) shown in Table 1 and Table 2, the same method as in Production Example 1 Similarly, the first mixed solution was prepared. Also, in addition to the contents (parts by mass) shown in Table 1 and Table 2, the ethylenically unsaturated compound (c) containing an alicyclic epoxy group (glycidyl methacrylate (GMA) in Production Example 8 ) and the catalyst, a second mixed solution was prepared in the same manner as in Production Example 1.

Except having used the said 1st mixed solution and said 2nd mixed solution, it carried out similarly to manufacture example 1, and obtained resin (A-2)-(A-8), (A-10)-(A-12). Resins (A-2) to (A-8), (A-10) to (A-12) were identified as the same as in Production Example 1, and they were represented by general formulas (2-2) to (2-8), Compounds represented by (2-10) to (2-12). The repeating unit k of the ^formula ( ^1-1 ) in the compounds represented by the general formulas (2-2)～(2-8) and (2-10) is R5 or R1 and R5 are ^two different types Repeat unit (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). 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 the 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, 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, m is 80, and n is 20).

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

(Manufacturing example 9) Except using the content (parts by mass) shown in Table 2, using the carboxyl group-containing ethylenically unsaturated monomer (a), ethylenically unsaturated monomer (d) and the polymerization initiator, prepare the same preparation as Production Example 1. 1 mix solution.

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

After dissolving 4-methoxyphenol, add 47.8 parts by mass of 2-isocyanatoethyl methacrylate (MOI) to the reaction system, continue stirring at 60°C for 8 hours, synthesize resin (A-9), and cool to room temperature temperature (23°C). Resin (A-9) was a compound represented by the general formula (2-9) as a result of the same identification as in Production Example 1. In the compound represented by general formula (2-9), the repeating unit k of formula (1-1) is two kinds of repeating units (k-1, k-2) with different 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).

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

Table 1 and Table 2 respectively show the carboxyl group-containing ethylenically unsaturated monomer (a) used in the manufacture of resins (A-1) to (A-12), and the ethylenically unsaturated monomer (a) that can be copolymerized with the above (a). Unsaturated monomer (d), polymerization initiator, alicyclic epoxy group-containing ethylenically unsaturated compound (c), catalyst, polymerization inhibitor, and solvent type and usage amount (parts by mass), methyl The amount (parts by mass) of glycidyl acrylate (GMA) and 2-isocyanatoethyl methacrylate (MOI).

[Examples 1-12, Comparative Examples 1-2] Add ethyl acetate as a solvent to the reaction solution of the resins (A-1) to (A-12) synthesized in Production Examples 1 to 12, and adjust the content of each resin (A-1) to (A-12) 30% by mass. The adhesive composition was obtained by the method shown below using the resin (A-1)-(A-12) solution whose content of resin (A-1)-(A-12) was 30 mass %.

Add the resin (A) and photopolymerization initiator (B ) and the crosslinking agent (C) were stirred together to obtain the adhesive compositions of Examples 1-12 and Comparative Examples 1-2. The values of resins (A-1) to (A-12) in Tables 4 to 6 are resins (A-1) to (A-12) whose content is 30% by mass. -12) The usage amount (parts by mass) of the solution. The numerical value of a photoinitiator (B) is the usage-amount (parts by mass) of the photoinitiator (B) with respect to 100 mass parts of resins (A). The numerical value of the crosslinking agent (C) is the usage-amount (mass part) of the crosslinking agent (C) with respect to 100 mass parts of resin (A).

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

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

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 method shown below. The results are shown in Tables 4 to 6.

"Peel strength before UV irradiation" Cut the adhesive sheet into a size of 25 mm in length and 100 mm in width, and peel off the peeling sheet to expose the adhesive layer. Next, the exposed adhesive layer (measurement surface) is in contact with the glass plate, the adhesive sheet is attached to the glass plate, and a 2kg rubber roller (width: about 50mm) is used to go back and forth once to make a sample for the measurement of the peel strength before UV irradiation. The obtained measurement samples were left in an environment with a temperature of 23°C and a humidity of 50% for 24 hours. Subsequently, according to JIS Z0237, a tensile test was performed at a peeling speed of 300mm/min in a direction of 180°, and the peel strength (N/25mm) of the adhesive sheet to the glass plate was measured.

"Peel strength after UV irradiation" is prepared in the same way as the sample for measuring the peel strength before UV irradiation, and irradiates ultraviolet (UV) from the side of the adhesive sheet at an irradiation dose of 500mJ/ ^cm2 to measure the peel strength after UV irradiation. sample. The UV irradiation system used a conveyor type ultraviolet irradiation device (manufactured by Eye Graphics, 2KW lamp, 80W/cm). The obtained sample for measurement was the same as the "peel strength before UV irradiation", and the peel strength (N/25mm) of the adhesive sheet to the glass plate was measured.

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

"fuzzy" The glass plate after measuring the peeling strength after UV irradiation was visually observed, and it evaluated by the following reference|standard. The results are shown in Tables 4 to 6. (evaluation criteria) ○: No adhesive remains on the glass plate. Δ: The adhesive remained on a part of the glass plate. × : The adhesive remains on the entire surface of the glass plate.

As shown in Table 4 and Table 5, the "peel strength before UV irradiation" of the adhesive sheets of Examples 1 to 12 was all above 1.0N/25mm, and the "peel strength after heat-resistant UV irradiation" was less than 2.5N/25mm, and the sticky Evaluation was ◯ or △. On the other hand, as shown in Table 6, the adhesive sheets of Comparative Example 1 and Comparative Example 2 in which the resin (A) did not contain a structure derived from an alicyclic compound had sufficiently low "peel strength after UV irradiation", but " The peel strength after heat-resistant UV irradiation is high, and the residual paste evaluation is ×.

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, n represent the molar composition ratio when k+l+m+n=100, k is more than 0~92, l is 0~50, m is More than 0~90, the total of k, l, m is 65~95, n is 5~35, R ¹ ~R ⁴ is -H or -CH ₃ , R ⁵ is an alkyl group with 1~16 carbons, R ⁶ is an alicyclic hydrocarbon group with 3 to 30 carbons or an aromatic hydrocarbon group with 6 to 20 carbons, R ⁷ is -H or -(CH ₂ ) _j -COOH (where j is 1 or 2), R ⁸ is Above general formula (1-2) or (1-3), in formula (1-2) and (1-3), p and q are selected from any one of 0, 1, 2, when p is 0 s is 0, and when p is 1 or 2, s is 1, and R ⁹ is -H or -CH ₃ ). The adhesive composition according to claim 1, wherein the weight average molecular weight of the above-mentioned 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 10-33. The adhesive composition according to claim 1 or 2, wherein k in the aforementioned formula (1-1) is 45-90, l is 4-40, and m is 1-15. The adhesive composition according to Claim 1 or 2, further comprising a crosslinking agent (C). The adhesive composition according to claim 1 or 2, wherein the glass transition temperature of the aforementioned 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 1-6.