KR20210068506A - Adhesive composition and adhesive sheet - Google Patents

Abstract

(a) a hydroxyl group-containing (meth)acrylic resin, (b) a hydroxyl group-containing modified unsaturated epoxy ester resin, (c) a polyisocyanate compound, and (d) a photopolymerization initiator; The epoxy ester resin has an ethylenically unsaturated group bonded to a secondary carbon atom derived from an epoxy group through an oxy group, and an α,β-unsaturated monobasic acid group bonded to a primary carbon atom derived from an epoxy group, b) the ester resin has or does not have an epoxy group, the number of α,β-unsaturated monobasic acid groups is equal to or greater than the number of epoxy groups, and (c) the polyisocyanate compound is a polyisocyanate derived from an aliphatic diisocyanate. to provide.

Description

Adhesive composition and adhesive sheet

The present invention relates to a pressure-sensitive adhesive composition and a pressure-sensitive adhesive sheet.

This application claims priority based on Japanese Patent Application No. 2018-229960 for which it applied to Japan on December 7, 2018, and uses the content here.

In recent years, the demand for the glass plate used for the front plate is rapidly increasing with the spread of a smartphone. The front plate of a smartphone is manufactured by the method of cutting out a plurality of glass plates of a desired size from one large glass plate conventionally, and grinding|polishing the cut surface of the cut out glass plate by a mechanical polishing process.

In recent years, in the manufacturing process of the front plate of a smartphone, it is calculated|required to shorten the grinding|polishing time of a cut surface. However, it is necessary to perform the mechanical grinding|polishing process performed in order to make the cut surface of a glass plate smooth, suppressing generation|occurrence|production of the crack of a glass plate, and a crack. For this reason, it is difficult to shorten the grinding|polishing time.

Then, instead of a mechanical polishing process, the method of making a cut surface smooth by melt|dissolving the cut surface of a glass plate using etching liquids, such as a hydrofluoric acid solution, is performed.

When processing the cut surface of a glass plate using etching liquid, it is necessary to protect the part (parts other than the cut surface of a glass plate) which does not etch from etching liquid. Conventionally, as a method of protecting the part which is not etched from an etching liquid of a glass plate, the method of sticking a protective tape on the part which is not etching a glass plate is used.

As a protective tape which protects a glass plate from etching liquid, there exists an adhesive tape in which the adhesive layer is provided in the surface of the resin base material containing polyethylene terephthalate (PET) resin etc.

For example, in patent document 1, when etching glass, it sticks to a non-etching part, and the protective sheet for glass etching which protects this non-etching part from etching liquid is described. The protective sheet for glass etching of patent document 1 is equipped with the base material and the adhesive layer provided in the single side|surface of this base material. The gel fraction of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is 60% or more, and the pressure-sensitive adhesive is an acrylic pressure-sensitive adhesive containing an acrylic polymer as a main component. This acrylic polymer is synthesized by polymerizing a monomer raw material containing a monomer represented _{by CH 2} =CR ¹ COOR ² (wherein, R ¹ is a hydrogen atom or a methyl group, and R ^{2 is an alkyl group) as a main monomer.} contains, as a main component, a monomer in which ^{R 2} in the above formula is an alkyl group having 6 or more carbon atoms.

In recent years, there exists a thing using a glass housing as a housing of a smartphone. In a glass housing, in order to improve designability, a plating process may be given to the surface. When plating a glass housing, it is performed by affixing a protective tape on the non-plating part of a glass housing. In the pretreatment of the plating treatment, surface treatment such as acid treatment and alkali treatment on the glass surface is performed.

However, even when the surface of an adherend subjected to surface treatment is protected using a conventional pressure-sensitive adhesive sheet, the treatment liquid used for the surface treatment may enter the interface between the pressure-sensitive adhesive sheet and the adherend to cause adverse effects. Specifically, even if the surface of the adherend subjected to the plating treatment is protected using the pressure-sensitive adhesive sheet, there is a case where the treatment liquid used for the pretreatment of the plating treatment enters the interface between the pressure-sensitive adhesive sheet and the adherend and the surface of the adherend is eroded. there was. For this reason, it is calculated|required that the adhesive sheet which protects the surface of the to-be-adhered body to which a plating process is given improves resistance with respect to the acidic treatment liquid and alkaline treatment liquid used in the pretreatment of a plating process.

As a method of preventing the intrusion of the processing liquid into the interface between the pressure-sensitive adhesive sheet and the adherend, it is considered to improve the adhesive force of the pressure-sensitive adhesive sheet. However, when an adhesive sheet with high adhesive force is used, the adhesive residue by which the adhesive layer of an adhesive sheet is transcribed will generate|occur|produce on the surface of the to-be-adhered body which peeled the adhesive sheet after surface treatment.

Japanese Patent Laid-Open No. 2013-40323

The present invention has been made in view of the above circumstances, and when used as a material for forming the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet, the penetration of the treatment liquid into the interface with the adherend can be suppressed, and the surface of the adherend from which the pressure-sensitive adhesive sheet is peeled off. It makes it a subject to provide the adhesive composition from which the adhesive sheet in which adhesive residual does not generate|occur|produce easily.

Another object of the present invention is to provide a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition.

MEANS TO SOLVE THE PROBLEM This inventor repeated earnest examination in order to solve the said subject. As a result, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet may be formed using a pressure-sensitive adhesive composition containing a hydroxyl group-containing (meth)acrylic resin, a specific modified unsaturated epoxy ester resin, a specific polyisocyanate compound, and a photopolymerization initiator. The invention was conceived. That is, the 1st aspect of this invention relates to the following adhesive compositions.

[1] (a) a hydroxyl group-containing (meth)acrylic resin, (b) a hydroxyl group-containing modified unsaturated epoxy ester resin, (c) a polyisocyanate compound, and (d) a photopolymerization initiator;

The (b) hydroxyl group-containing modified unsaturated epoxy ester resin is an ethylenically unsaturated group bonded to a secondary carbon atom derived from an epoxy group through an oxy group, and α,β-unsaturated bonded to a primary carbon atom derived from an epoxy group Having a monobasic acid group, the (b) hydroxyl group-containing modified unsaturated epoxy ester resin has or does not have an epoxy group, the number of α,β-unsaturated monobasic acid groups is greater than or equal to the number of epoxy groups, and the (c) polyisocyanate compound It is a polyisocyanate derived from this aliphatic diisocyanate, The adhesive composition characterized by the above-mentioned.

The pressure-sensitive adhesive composition of the first aspect preferably includes the following characteristics.

[2] The pressure-sensitive adhesive composition according to [1], wherein the (b) hydroxyl group-containing modified unsaturated epoxy ester resin has an unsaturated epoxy ester resin structure derived from a reaction product of a bisphenol-type epoxy resin and (meth)acrylic acid.

[3] The pressure-sensitive adhesive composition according to [1] or [2], wherein the (b) hydroxyl group-containing modified unsaturated epoxy ester resin is a compound represented by the following formula (1).

(in formula (1), two R ¹ are independently a hydrogen atom or a methyl group; R ² is a hydrogen atom or a group having an ethylenically unsaturated bond; X is a repeating unit comprising a group derived from an epoxy resin; n is is an integer from 1 to 100; when R ² is a hydrogen atom, [X] _n has at least one group having an ethylenically unsaturated bond; when n is 2 to 100, X may be one type or two or more .)

[4] The pressure-sensitive adhesive composition according to [3], wherein X is represented by the following formula (2) or the following formula (3).

(In formula (2), two R ³ are independently a hydrogen atom or a methyl group; R ⁴ is a hydrogen atom or a group having an ethylenically unsaturated bond.)

(In formula (3), two R ⁵ are independently a hydrogen atom or a methyl group; R ⁶ is a hydrogen atom or a group having an ethylenically unsaturated bond.)

[5] The content of the (c) polyisocyanate compound is 1 to 10 parts by mass relative to a total of 100 parts by mass of the (a) hydroxyl group-containing (meth)acrylic resin and (b) the hydroxyl group-containing modified unsaturated epoxy ester resin, [1] ] to [4], the pressure-sensitive adhesive composition according to any one of.

[6] The pressure-sensitive adhesive according to any one of [1] to [5], wherein the mass ratio of the (a) hydroxyl group-containing (meth)acrylic resin to the (b) hydroxyl group-containing modified unsaturated epoxy ester resin is 60:40 to 40:60. composition.

A 2nd aspect of this invention relates to the following adhesive sheet.

[7] A pressure-sensitive adhesive layer is provided on one side of the substrate,

The pressure-sensitive adhesive layer comprises the pressure-sensitive adhesive composition according to any one of [1] to [6], the pressure-sensitive adhesive sheet.

The pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition of the present invention can suppress the intrusion of the treatment liquid into the interface with the adherend, and adhesive residue is less likely to occur on the surface of the adherend from which the pressure-sensitive adhesive sheet is peeled.

Hereinafter, preferred examples of the pressure-sensitive adhesive composition and pressure-sensitive adhesive sheet of the present invention will be described in detail. In addition, this invention is not limited only to embodiment described below. Various changes, omissions, combinations, exchanges, and/or additions are possible without departing from the spirit of the present invention.

[Adhesive composition]

The present inventors repeated intensive studies, and as a result, (a) a hydroxyl group-containing (meth)acrylic resin, (b) a hydroxyl group-containing modified unsaturated epoxy ester resin, (c) a polyisocyanate compound, and (d) a photopolymerization initiator (b) a hydroxyl group-containing modified unsaturated epoxy ester resin, an ethylenically unsaturated group bonded to a secondary carbon atom derived from an epoxy group through an oxy group, α,β bonded to a primary carbon atom derived from an epoxy group - When a pressure-sensitive adhesive composition having unsaturated monobasic acid groups, the number of α,β-unsaturated monobasic acid groups is greater than or equal to the number of epoxy groups, and (c) the polyisocyanate compound is a polyisocyanate derived from an aliphatic diisocyanate, very good results are obtained. found out what to get.

(b) the hydroxyl group-containing modified unsaturated epoxy ester resin, wherein an ethylenically unsaturated group is introduced into a part of secondary hydroxyl groups in the unsaturated epoxy ester resin structure, and 50 mol% or more of α,β-unsaturated with respect to the epoxy group of the raw material epoxy resin When resin to which monobasic acid was added was used for an adhesive composition, the present inventors discovered that favorable results were obtained.

The said adhesive composition contains said (a) hydroxyl-group containing (meth)acrylic resin, said (b) hydroxyl-containing modified unsaturated epoxy ester resin, and said (c) polyisocyanate compound. For this reason, the hydroxyl group contained in the said (a) component and (b) component, and the isocyanato group of the said (c) component react by heating, and form a crosslinked structure. Therefore, it is excellent in tolerance with respect to an acid solution and an alkali solution, and can form the adhesive layer which has high adhesive force with respect to to-be-adhered bodies, such as a glass plate. Therefore, the pressure-sensitive adhesive sheet having the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition can suppress the penetration of the treatment liquid into the interface with the adherend.

In addition, the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition is cured by irradiating light such as ultraviolet (UV) light, (b) the ethylenically unsaturated group in the hydroxyl group-containing modified unsaturated epoxy ester resin reacts to form a further crosslinked structure. As a result, the adhesive force is changed. Specifically, sufficient adhesion to the adherend is obtained before light irradiation on the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition, and after light irradiation, the adhesion is lowered to facilitate peeling, thereby preventing adhesive residue on the adherend after peeling can do.

[Features of the pressure-sensitive adhesive composition]

The pressure-sensitive adhesive composition of the present embodiment includes (a) a hydroxyl group-containing (meth)acrylic resin, (b) a hydroxyl group-containing modified unsaturated epoxy ester resin (hereinafter sometimes referred to as “modified epoxy ester resin”), and (c) poly An isocyanate compound and (d) a photoinitiator are included.

Each component is described in detail below.

In this specification, "(meth)acrylic resin" means at least 1 sort(s) chosen from an acrylic resin and a methacryl resin.

<(a) Hydroxyl group-containing (meth)acrylic resin>

The (a) hydroxyl group containing (meth)acrylic resin contained in the adhesive composition of this embodiment is a polymer which has a structural unit derived from a (meth)acrylic acid ester monomer as a main component.

(a) When the (meth)acrylic resin containing a hydroxyl group is a copolymer, any of a random copolymer, a block copolymer, and an alternating copolymer may be sufficient.

(a) Hydroxyl group-containing (meth)acrylic resin has one or more hydroxyl groups in 1 molecule. (a) The hydroxyl group which has a hydroxyl-group containing (meth)acrylic resin becomes a crosslinking point which reacts with the (c) polyisocyanate compound by heat|fever. Therefore, by including (a) a hydroxyl-group containing (meth)acrylic resin, it becomes the adhesive composition from which the adhesive layer which has the outstanding cohesive force and does not easily remain in an adhesive is obtained.

In the pressure-sensitive adhesive composition of the present embodiment (a), the hydroxyl group-containing (meth)acrylic resin may be included in one type or two or more types may be included.

(a) As a hydroxyl-group containing (meth)acrylic resin, it is preferable that weight average molecular weights are 200,000-2 million, It is more preferable that it is 200,000-1,500,000, It is still more preferable that it is 400,000-1,000,000. (a) If the weight average molecular weight of a hydroxyl-group containing (meth)acrylic resin is 200,000 or more, it becomes the adhesive composition from which the adhesive layer which adhesive residue does not generate|occur|produce more easily is obtained. (a) If the weight average molecular weight of hydroxyl group containing (meth)acrylic resin is 2 million or less, the adhesive composition of the viscosity which is easy to apply|coat is easy to be obtained, and it is preferable.

(a) As the hydroxyl group-containing (meth)acrylic resin, it is preferable to use a glass transition temperature (Tg) of -80 to 0°C, more preferably -60 to -10°C, and -40 to -10°C. It is more preferable that (a) When the glass transition temperature of (meth)acrylic resin containing a hydroxyl group is -80 degreeC or more, it is excellent in compatibility with (b) hydroxyl-containing modified|denatured unsaturated epoxy ester resin. Moreover, adhesive force falls easily after light irradiation, and it becomes the adhesive composition from which the adhesive layer in which adhesive residual does not generate|occur|produce more easily. (a) It becomes the adhesive composition from which the adhesive layer which has a more favorable adhesive force as the glass transition temperature of a hydroxyl-group containing (meth)acrylic resin is 0 degrees C or less.

(a) The hydroxyl group-containing (meth)acrylic resin preferably has a hydroxyl value of more than 0 to 40 mgKOH/g, more preferably 1 to 20 mgKOH/g, and more preferably 1 to 10 mgKOH/g. more preferably. When the hydroxyl value is more than 0, (a) the hydroxyl group of the hydroxyl group-containing (meth)acrylic resin becomes a crosslinking point at which the (c) polyisocyanate reacts. For this reason, sufficient cohesive force is acquired, it becomes difficult for an adhesive to remain, and it becomes an adhesive composition from which the adhesive layer which can fully suppress penetration of the processing liquid to the interface with a to-be-adhered body is obtained. Moreover, it becomes an adhesive composition which can form the adhesive layer which has sufficient initial stage adhesive force as a hydroxyl value is 40 mgKOH/g or less.

(a) As a hydroxyl group containing (meth)acrylic resin, it is preferable to use the thing whose acid value is 0-40 mgKOH/g, It is more preferable that it is 1-20 mgKOH/g, It is more preferable that it is 3-10 mgKOH/g. (a) Even if the adhesive composition whose acid value of a hydroxyl-group containing (meth)acrylic resin is the range of 0-40 mgKOH/g contact|connects an alkaline solution, an adhesive layer is hard to swell. For this reason, (a) the pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition having an acid value of the hydroxyl group-containing (meth)acrylic resin in the above range can further suppress the penetration of the treatment liquid into the interface with the adherend. becomes a thing

((a) Method for producing hydroxyl group-containing (meth)acrylic resin)

(a) The hydroxyl group-containing (meth)acrylic resin may be prepared by an arbitrarily selected method, and may be prepared by a method of polymerizing a raw material monomer including a (meth)acrylic acid ester monomer. In particular, using a monomer having a hydroxyl group such as hydroxyethyl (meth) acrylate and alkyl (meth) acrylate as a raw material monomer, it is convenient and preferable to prepare it using a method of copolymerizing them. (a) The hydroxyl group-containing (meth)acrylic resin may be prepared by copolymerizing a raw material monomer containing glycidyl (meth)acrylate, then ring-opening an epoxy group to generate a hydroxyl group.

(a) The (meth)acrylic acid ester monomer used as a raw material monomer of a hydroxyl-group containing (meth)acrylic resin may be used individually by 1 type, and may be used in combination of 2 or more type.

(a) There is no limitation in particular as a (meth)acrylic acid ester monomer used as a raw material monomer of a hydroxyl-containing (meth)acrylic resin, A hydroxyl-containing (meth)acrylate, a carboxyl group-containing (meth)acrylate, an alkyl (meth)acrylate , Cyclic alkyl (meth) acrylate, alkoxyalkyl (meth) acrylate, alkoxy (poly) alkylene glycol (meth) acrylate, (meth) acrylamide, sulfonic acid group-containing (meth) acrylate, alkyl fluoride (meth) (meth)acrylate which has an acrylate, an epoxy group, (meth)acrylate which has a plurality of (meth)acryloyl groups, etc. are mentioned.

In this specification, "(meth)acrylate" means at least 1 sort(s) chosen from an acrylate and a methacrylate.

Further, in the present specification means that at least one member selected from the "(meth) acryloyl group" is, CH ₂ = CH-CO- and _{CH 2 = C (CH 3)} -CO-.

(a) Among the above-mentioned (meth)acrylic acid ester monomers used as raw material monomers of (meth)acrylic resin containing a hydroxyl group, (meth)acrylate containing a hydroxyl group is (a) containing a hydroxyl group in the (meth)acrylic resin containing a hydroxyl group. It is a useful monomer for

Examples of the hydroxyl group-containing (meth)acrylate include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 1,3-butanediol. (meth)acrylate, 1,4-butanediol (meth)acrylate, 1,6-hexanediol (meth)acrylate, 3-methylpentanediol (meth)acrylate, etc. are mentioned. Among these, 2-hydroxyethyl (meth)acrylate is preferable especially since it has favorable reactivity with the (c) polyisocyanate compound and it is easy to obtain.

As the carboxyl group-containing (meth)acrylate, for example, β-carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyl Oxyethyl phthalic acid, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, etc. are mentioned.

(a) The carboxyl group that the carboxyl group-containing (meth)acrylate used as a raw material of the (a) hydroxyl group-containing (meth)acrylic resin has is, (a) in the hydroxyl group-containing (meth)acrylic resin, (c) the polyisocyanate compound and the reactive crosslinking point do. Therefore, it becomes the adhesive composition from which it has the more outstanding cohesive force and the adhesive layer from which an adhesive is hard to remain by including a carboxyl group containing (meth)acrylate is obtained.

Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, tert-butyl (meth) acrylic Rate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, n-hexyl (meth) acrylate, isooctyl (meth) acrylate, isostearyl (meth) ) acrylate, lauryl (meth)acrylate, and tridecyl (meth)acrylate.

As an alkyl (meth)acrylate, it is preferable to use the alkyl (meth)acrylate which has a C1-C4 alkyl group especially among these. (a) The (meth)acrylic acid ester monomer used as a raw material of the hydroxyl group-containing (meth)acrylic resin contains an alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms, so that the adhesion with the adherend is further excellent. It becomes the adhesive composition from which an adhesive layer is obtained.

As cyclic alkyl (meth)acrylate, for example, cyclohexyl (meth)acrylate, norbornyl (meth)acrylate, isobornyl (meth)acrylate, norbornanyl (meth)acrylate, dicyclophene Tenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, tricyclodecanedimethyloldi (meth) acrylate, etc. can be heard

As alkoxyalkyl (meth)acrylate, for example, ethoxyethyl (meth)acrylate, methoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, 2-methoxyethoxyethyl (meth)acryl a rate, 2-ethoxyethoxyethyl (meth)acrylate, etc. are mentioned.

Examples of the alkoxy (poly) alkylene glycol (meth) acrylate include methoxydiethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, and methoxydipropylene glycol (meth) acrylate. have.

As (meth)acrylamide, (meth)acrylamide, N-methyl (meth)acrylamide, N-ethyl (meth)acrylamide, N-propyl (meth)acrylamide, N-isopropyl acrylamide, N-hexyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, (meth)acryloylmorpholine, diacetoneacrylamide, etc. are mentioned. .

As sulfonic acid group containing (meth)acrylate, 2-sulfoethyl (meth)acrylate etc. are mentioned, for example.

Examples of the fluorinated alkyl (meth)acrylate include octafluoropentyl (meth)acrylate.

As (meth)acrylate which has an epoxy group, glycidyl (meth)acrylate etc. are mentioned, for example.

As (meth)acrylate which has a plurality of (meth)acryloyl groups, for example, polyethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, triethylene Glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc. are mentioned.

(a) The raw material monomer of a hydroxyl group-containing (meth)acrylic resin may contain 1 or more types of other polymerizable monomers other than a (meth)acrylic acid ester monomer as a copolymerization component in the range which does not impair polymerizability.

It is preferable that especially (meth)acrylic acid is included as another polymerizable monomer. The carboxyl group (-COOH) contained in (meth)acrylic acid becomes a crosslinking point which reacts with (c) a polyisocyanate compound in (a) a hydroxyl-group containing (meth)acrylic resin. Therefore, the pressure-sensitive adhesive composition containing (a) a hydroxyl group-containing (meth)acrylic resin prepared by copolymerizing a raw material monomer containing (meth)acrylic acid has a more excellent cohesive force, and a pressure-sensitive adhesive layer in which the pressure-sensitive adhesive is more difficult to remain is obtained. do. Therefore, it is preferable to use (meth)acrylic acid as one of the raw material monomers.

It is preferable that the usage ratio (content) of (meth)acrylic acid in a raw material monomer is 0.1-5 mass %, More preferably, it is 0.5-3 mass %. When the use ratio of (meth)acrylic acid is 0.1 mass % or more, (a) the hydroxyl group-containing (meth)acrylic resin reacts with (c) the polyisocyanate compound to improve cohesion, and to further reduce the adhesive residue on the adherend It becomes a pressure-sensitive adhesive composition that can be used. When the usage ratio of (meth)acrylic acid is 5 mass % or less, it becomes an adhesive composition which has sufficient adhesive force with respect to a to-be-adhered body.

Examples of the polymerizable monomer other than (meth)acrylic acid include acrylonitrile, methacrylonitrile, styrene, α-methylstyrene, vinyl acetate, vinyl propionate, vinyl stearate, vinyl chloride, vinylidene chloride, alkyl vinyl. Ether, vinyl toluene, vinyl pyridine, vinyl pyrrolidone, itaconic acid dialkyl ester, fumaric acid dialkyl ester, allyl alcohol, acryl chloride, methyl vinyl ketone, allyl trimethyl ammonium chloride, dimethyl allyl vinyl ketone, etc. are mentioned.

(a) as a raw material monomer of a hydroxyl group-containing (meth)acrylic resin, since it becomes a pressure-sensitive adhesive composition from which a pressure-sensitive adhesive layer having good water resistance and excellent resistance to acid and alkaline solutions is obtained, hydroxyl group-containing (meth)acrylate, It is preferable to further include at least one monomer selected from carboxyl group-containing (meth)acrylate and alkyl (meth)acrylate. In this raw material monomer, it is also preferable from the viewpoints of availability and reactivity to contain (meth)acrylic acid together with the carboxyl group-containing (meth)acrylate or instead of the carboxyl group-containing (meth)acrylate.

As a raw material monomer, 2-hydroxyethyl (meth)acrylate is specifically included as a hydroxyl-group containing (meth)acrylate, and n-butyl (meth)acrylate, ethyl (meth)acrylate which is an alkyl (meth)acrylate further It is more preferable to use the thing containing 1 or more types chosen from acrylate and methyl (meth)acrylate, and methacrylic acid and/or acrylic acid.

(a) The preferable usage ratio of the following monomer in the raw material monomer of a hydroxyl-group containing (meth)acrylic resin is as follows.

The proportion of the hydroxyl group-containing (meth)acrylate used in the raw material monomer is preferably 0.1 to 5 mass%, more preferably 0.5 to 3 mass%. When the use ratio of the hydroxyl group-containing (meth)acrylate is 0.1 mass % or more, (a) the hydroxyl group-containing (meth)acrylic resin reacts with the (c) polyisocyanate compound to improve cohesive force and reduce the adhesive residue on the adherend It becomes a pressure-sensitive adhesive composition that can be made. It becomes an adhesive composition which has sufficient adhesive force with respect to a to-be-adhered body that the usage ratio of a hydroxyl-group containing (meth)acrylate is 5 mass % or less.

The usage ratio in the raw material monomer of a carboxy group containing (meth)acrylate becomes like this. Preferably it is 0.1-5 mass %, More preferably, it is 0.5-3 mass %. When the use ratio of the carboxyl group-containing (meth)acrylate is 0.1% by mass or more, (a) the hydroxyl group-containing (meth)acrylic resin reacts with the (c) polyisocyanate compound to improve cohesive force, and the adhesive residue to the adherend is further reduced It becomes an adhesive composition which can further reduce. It becomes an adhesive composition which has sufficient adhesive force with respect to a to-be-adhered body that the usage ratio of a carboxy group containing (meth)acrylate is 5 mass % or less.

The use ratio in the raw material monomer of alkyl (meth)acrylate becomes like this. Preferably it is 70-99 mass %, More preferably, it is 80-95 mass %. It becomes the adhesive composition from which the adhesive layer excellent in the tolerance with respect to an acid solution and an alkali solution is obtained as the usage rate of an alkyl (meth)acrylate is 70 mass % or more. It becomes the adhesive composition from which the adhesive layer which can reduce the adhesive residue with respect to a to-be-adhered body that the usage ratio of an alkyl (meth)acrylate is 99 mass % or less is obtained.

The use ratio in the raw material monomer of the total of the hydroxyl group-containing (meth)acrylate, the carboxyl group-containing (meth)acrylate, (meth)acrylic acid, and monomers other than the alkyl (meth)acrylate contained in the raw material monomer, Preferably it is 0.1-15 mass %, More preferably, it is 1-5 mass %.

(a) The method of polymerizing the raw material monomer for producing the hydroxyl group-containing (meth)acrylic resin is not particularly limited, and known methods such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, and alternating copolymerization can be used. . Among these polymerization methods, solution polymerization is particularly suitable from the viewpoints of (a) the cost of the hydroxyl group-containing (meth)acrylic resin.

(a) A polymerization initiator may be used when polymerizing a raw material monomer to prepare a hydroxyl group-containing (meth)acrylic resin. It does not specifically limit as a polymerization initiator, It can select suitably from a well-known thing and can use it. For example, 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-carbonitrile), 2,2'-azobis ( azo polymerization initiators such as 2,4,4-trimethylpentane) and dimethyl-2,2-azobis(2-methylpropionate); Benzoyl peroxide, t-butylhydroperoxide, di-t-butylperoxide, t-butylperoxybenzoate, dicumylperoxide, 1,1-bis(t-butylperoxy)3,3,5- Oil-soluble polymerization initiators, such as peroxide type polymerization initiators, such as trimethylcyclohexane and 1, 1-bis (t-butylperoxy) cyclododecane, can be illustrated.

These polymerization initiators may be used independently and may be used in combination of 2 or more type.

The amount of the polymerization initiator to be used can be arbitrarily selected, and (a) 0.01 to 5 parts by mass, more preferably 0.02 to 4 parts by mass, with respect to a total of 100 parts by mass of raw material monomers used for polymerization of (a) hydroxyl group-containing (meth)acrylic resin, It is more preferable that it is 0.03-3 mass parts.

(a) When producing a hydroxyl group-containing (meth)acrylic resin by solution polymerization, various general 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; cyclohexane; Organic solvents, such as ketones, such as alicyclic hydrocarbons, such as methylcyclohexane, methyl ethyl ketone, and methyl isobutyl ketone, are mentioned. These solvents may be used independently and may be used in combination of 2 or more type.

<(b) hydroxyl group-containing modified unsaturated epoxy ester resin>

The (b) hydroxyl group-containing modified unsaturated epoxy ester resin contained in the pressure-sensitive adhesive composition is a modified product of the (b-1) unsaturated epoxy ester resin. (b-1) The unsaturated epoxy ester resin is, for example, "Eiichiro Takiyama, Polyester Resin Handbook" (Edited by Nikkan High School Shinbunsha, published in 1988) or "Paint Glossary" (Edited by Kyokai Shikizai, 1993) year publication), etc.

(b) The hydroxyl group-containing modified unsaturated epoxy ester resin is a resin into which an ethylenically unsaturated group is introduced into a part of the secondary hydroxyl group in the unsaturated epoxy ester resin structure of the (b) hydroxyl group-containing modified unsaturated epoxy ester resin. (b) Hydroxyl group containing modified|denatured unsaturated epoxy ester resin is resin obtained by introduce|transducing an ethylenically unsaturated group into a part of secondary hydroxyl groups in (b-1) unsaturated epoxy ester resin before modification. Modification means that the ethylenically unsaturated group is introduce|transduced into a part of secondary hydroxyl group in (b-1) unsaturated epoxy ester resin.

In the pressure-sensitive adhesive composition of the present embodiment, (b) one type of hydroxyl group-containing modified unsaturated epoxy ester resin may be contained, or two or more types may be contained.

(b) the hydroxyl group-containing modified unsaturated epoxy ester resin is derived from the epoxy group of the (b-2) epoxy resin, which is a raw material of the (b-1) unsaturated epoxy ester resin, before the modification, the second represented by an arrow in the following formula (5) An ethylenically unsaturated group bonded to a primary carbon atom through an oxy group (-O-), and an α,β-unsaturated monobasic group bonded to a primary carbon atom represented by an arrow in the following formula (5) derived from the epoxy group have acidity

(b) Hydroxyl group-containing modified unsaturated epoxy ester resin has one or more hydroxyl groups in one molecule. (b) The hydroxyl group which modified epoxy ester resin has becomes a crosslinking point which reacts with (c) a polyisocyanate compound when an adhesive composition is heated. (b) It is preferable that the hydroxyl group which modified epoxy ester resin has is the residue which generate|occur|produced by ring-opening of an epoxy group. The hydroxyl group is a secondary carbon atom derived from the epoxy group of the (b) hydroxyl group-containing modified unsaturated epoxy ester resin, and is preferably bonded to a secondary carbon atom to which the ethylenically unsaturated group is not bonded via an oxy group.

(b) in the modified unsaturated epoxy ester resin containing a hydroxyl group, the ethylenically unsaturated group bonded to the secondary carbon atom derived from the epoxy group of the raw material (b-2) epoxy resin through an oxy group is exposed to light such as ultraviolet (UV) light By irradiation, a crosslinked structure is formed. Thereby, (b) hydroxyl-group containing modified|denatured unsaturated epoxy ester resin has the function of reducing the adhesive force after light irradiation in the adhesive layer containing an adhesive composition. One or more of the ethylenically unsaturated groups bonded to the secondary carbon atom derived from the epoxy group via an oxy group (b) may be contained in one molecule of the hydroxyl group-containing modified unsaturated epoxy ester resin. The ethylenically unsaturated group may be bonded to the primary carbon atom derived from the epoxy group of the (b) hydroxyl group-containing modified unsaturated epoxy ester resin via an oxa bond.

An ethylenically unsaturated group bonded to a secondary carbon atom derived from an epoxy group through an oxy group is a group having an ethylenically unsaturated bond, for example, a residue obtained by removing a hydroxyl group from an α,β-unsaturated monobasic acid, (meth)acrylo and a device having a diary. Specific examples of the ethylenically unsaturated group include groups bonded by a urethane bond such as _{CH 2} =CHCOOCH ₂ CH ₂ -NHCO-, CH ₂ =C(CH ₃ )COOCH ₂ CH _{2 -NHCO-, α,β} - A (meth)acryloyl group, a crotonyl group, etc. which are residues obtained by removing a hydroxyl group from an unsaturated monobasic acid are mentioned. Among these ethylenically unsaturated groups, a pressure-sensitive adhesive composition with particularly good photocurability is obtained, and (b) since the raw material used for producing the modified unsaturated epoxy ester resin containing a hydroxyl group is readily available, CH ₂ =C(CH ₃ )COOCH _{A 2} CH ₂ -NHCO- or (meth)acryloyl group is preferred. (b) When the hydroxyl group-containing modified unsaturated epoxy ester resin has a plurality of ethylenically unsaturated groups in one molecule, the number of types of the ethylenically unsaturated groups in the molecule may be one or two or more.

(b) in the modified unsaturated epoxy ester resin containing a hydroxyl group, among all the secondary carbon atoms derived from the epoxy group of the raw material (b-2) epoxy resin, the number of ethylenically unsaturated groups bonded through an oxy group is 30 It is preferable that it is 95 mol%, and it is more preferable that it is 40-90 mol%. When the number of ethylenically unsaturated groups bonded through an oxy group with respect to the number of secondary carbon atoms derived from the epoxy group is 30 mol% or more, the pressure-sensitive adhesive composition is irradiated with light such as ultraviolet (UV) light to form a sufficient crosslinked structure. For this reason, the adhesive force after light irradiation in the adhesive layer containing an adhesive composition fully falls. In addition, when the number of ethylenically unsaturated groups is 95 mol% or less, it is a secondary carbon atom derived from an epoxy group, and a hydroxyl group can be bonded to a secondary carbon atom to which an ethylenically unsaturated group is not bonded through an oxy group. . Thereby, the number of the hydroxyl groups which react with the (c) polyisocyanate compound contained in (b) hydroxyl-group containing modified|denatured unsaturated epoxy ester resin can fully be ensured. Therefore, it becomes an adhesive composition from which the adhesive layer excellent in water resistance and resistance to an acid solution and an alkali solution is obtained.

(b) The number of α,β-unsaturated monobasic acid groups in the hydroxyl group-containing modified unsaturated epoxy ester resin is equal to or greater than the number of epoxy groups. (b) The hydroxyl group-containing modified unsaturated epoxy ester resin is obtained by adding 50 mol% or more of α,β-unsaturated monobasic acid to the epoxy groups of the raw material (b-2) epoxy resin, and α,β-unsaturated monobasic acid groups The number of is greater than or equal to the number of remaining epoxy groups. In other words, the ratio of α,β-unsaturated monobasic acid groups to the total number of moles of the number of α,β-unsaturated monobasic acid groups and the number of epoxy groups bonded to primary carbon atoms derived from the epoxy group is 50 mol% or more .

(b) The hydroxyl group-containing modified unsaturated epoxy ester resin is preferably 65 to 100 mol%, more preferably 80 to 100 mol% of α,β-unsaturated monoyl, based on the epoxy group of the raw material (b-2) epoxy resin. It is preferable that it is resin to which the basic acid group was added. (b) The hydroxyl group-containing modified unsaturated epoxy ester resin may not have an epoxy group and may have an unreacted epoxy group to which an α,β-unsaturated monobasic acid group is not added.

(b) In the modified unsaturated epoxy ester resin containing a hydroxyl group, the α,β-unsaturated monobasic acid group bonded to the primary carbon atom derived from the epoxy group is irradiated with light such as ultraviolet (UV) light to form a crosslinked structure. In the present embodiment, (b) since the number of α,β-unsaturated monobasic acid groups in the hydroxyl group-containing modified unsaturated epoxy ester resin is equal to or greater than the number of epoxy groups, the function of reducing the adhesive force after light irradiation in the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition This is sufficiently obtained. Therefore, it becomes the adhesive composition from which the adhesive layer with which an adhesive is hard to remain is obtained.

As an α,β-unsaturated monobasic acid group bonded to a primary carbon atom derived from an epoxy group, a hydrogen atom is removed from an α,β-unsaturated monobasic acid such as methacrylic acid, acrylic acid, crotonic acid, cinnamic acid, and sorbic acid. residues. Among these α,β-unsaturated monobasic acid groups, a (meth)acryloyloxy group is preferable because the decrease in the adhesive force after light irradiation in the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition is particularly good. (b) When the hydroxyl group-containing modified unsaturated epoxy ester resin has a plurality of α,β-unsaturated monobasic acid groups in one molecule, the type of α,β-unsaturated monobasic acid group in the molecule may be one or two or more. .

(b) The hydroxyl value of the hydroxyl group-containing modified unsaturated epoxy ester resin is preferably 5 to 90 mgKOH/g, more preferably 15 to 85 mgKOH/g, still more preferably 30 to 80 mgKOH/g. 30-60 mgKOH/g or 40-70 mgKOH/g may be sufficient as needed. If hydroxyl value is 5 mgKOH/g or more, it will become (b) hydroxyl-group containing modified|denatured unsaturated epoxy ester resin in which hydroxyl group is fully contained. As a result, (b) the hydroxyl group of the hydroxyl group-containing modified unsaturated epoxy ester resin becomes a crosslinking point that reacts with (c) polyisocyanate when the pressure-sensitive adhesive composition is heated, and sufficient cohesive force is obtained. It becomes an adhesive composition which can form the adhesive layer which can fully suppress the penetration|invasion of the processing liquid to . Moreover, it becomes an adhesive composition which can form the adhesive layer which has sufficient initial stage adhesive force as a hydroxyl value is 90 mgKOH/g or less.

(b) The hydroxyl value of hydroxyl-group containing modified unsaturated epoxy ester resin can be measured by the method similar to the hydroxyl value of (a) hydroxyl-group containing (meth)acrylic resin.

(b) The hydroxyl group-containing modified unsaturated epoxy ester resin preferably has an unsaturated epoxy ester resin structure derived from a reaction product of a bisphenol-type epoxy resin and an α,β-unsaturated monobasic acid. That is, it is preferable that (b) hydroxyl-group containing modified unsaturated epoxy ester resin is resin to which (alpha), beta -unsaturated monobasic acid group was added with respect to the epoxy group of a bisphenol-type epoxy resin. (b) when the hydroxyl group-containing modified unsaturated epoxy ester resin has an unsaturated epoxy ester resin structure derived from a bisphenol-type epoxy resin, the pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition of the present embodiment, the adhesive strength by light irradiation The decline becomes significant. In particular, (b) the hydroxyl group-containing modified unsaturated epoxy ester resin preferably has an unsaturated epoxy ester resin structure derived from a reaction product of a bisphenol-type epoxy resin and (meth)acrylic acid.

(b) It is preferable that hydroxyl-group containing modified|denatured unsaturated epoxy ester resin is a compound represented by following formula (1).

(in formula (1), two R ¹ are independently a hydrogen atom or a methyl group. R ² is a hydrogen atom or a group having an ethylenically unsaturated bond. X is a repeating unit comprising a group derived from an epoxy resin. n is It is an integer of 1 to 100. When R ² is a hydrogen atom, [X] _n has at least one group having an ethylenically unsaturated bond. When n is 2 to 100, X may be one type or two or more types. .)

In Formula (1), two R<^1> is a hydrogen atom or a methyl group independently. ^{When two R<1>} in Formula (1) are the same, since it can manufacture easily, it is preferable.

In Formula (1), R<^2> is a hydrogen atom or group which has an ethylenically unsaturated bond.

When R ² is a hydrogen atom, that ^{is, when -OR 2} is a hydroxyl group, the pressure-sensitive adhesive composition is heated so that (b) the hydroxyl group of the hydroxyl group-containing modified unsaturated epoxy ester resin reacts with the (c) polyisocyanate compound. And (b) hydroxyl group-containing modified unsaturated epoxy ester resin takes a crosslinked structure with (a) hydroxyl group-containing (meth)acrylic resin via (c) polyisocyanate compound. As a result, the adhesive sheet which has an adhesive layer containing the said adhesive composition can prevent the adhesive residue with respect to the to-be-adhered body after peeling more effectively.

Examples of R ² in R ² is a group having an ethylenically unsaturated bond case, there may be mentioned the same that the ethylenically unsaturated group bonded through an oxy a second grade of carbon atoms derived from the above-mentioned epoxy group. Specifically, for example, a residue obtained by removing a hydroxyl group from an α,β-unsaturated monobasic acid such as a (meth)acryloyl group or a _{crotonyl group, CH 2} =CHCOOCH ₂ CH ₂ -NHCO-, CH ₂ =C(CH) ₃ ) A group bonded by a urethane bond, such as _{COOCH 2} CH _{2 -NHCO-, may be mentioned.} Among the groups having an ethylenically unsaturated bond, R ² is a (meth)acryloyl group or CH ₂ ═C(CH ₃ )COOCH ₂ CH ₂ —NHCO— desirable. In addition, when R ² is a group bonded by a urethane bond (-NHCO-), (b) the pressure-sensitive adhesive composition comprising a hydroxyl group-containing modified unsaturated epoxy ester resin has better resistance to acid and alkaline solutions. desirable.

In formula (1), X is a repeating unit containing the group derived from the (b-2) epoxy resin. It is preferable that X is group obtained by ring-opening an epoxy group by superposing|polymerizing the compound containing an epoxy group.

In Formula (1), n is an integer of 1-100, it is preferable that it is an integer of 1-10, It is more preferable that it is an integer of 1-4. It is more preferable that n is 1, 2, 3 and/or 4. When n is 2 to 100, X may be one type or two or more types.

In Formula (1), when R<^2> is a hydrogen atom, [X] _n has at least 1 group which has an ethylenically unsaturated bond. As group which has an ethylenically unsaturated bond which [X] _n has, the group similar to what can be used as ^{R<2> is mentioned.}

(b) When the hydroxyl group-containing modified unsaturated epoxy ester resin is a compound represented by the formula (1), it is preferable that X in the formula (1) is represented by the following formula (2) or the following formula (3).

(In formula (2), two R ³ are independently a hydrogen atom or a methyl group. R ⁴ is a hydrogen atom or a group having an ethylenically unsaturated bond.)

(In formula (3), two R ⁵ are independently a hydrogen atom or a methyl group. R ⁶ is a hydrogen atom or a group having an ethylenically unsaturated bond.)

When X in Formula (1) is represented by Formula (2), two R<^3> in Formula (2) is a hydrogen atom or a methyl group independently. When n in Formula (1) is 2 or more, R<^3> may be the same as for all of some X _{which comprises [X]n} ^{, and some or all R<3>} of some X may be different.

When X in Formula (1) is represented by Formula (2), R ⁴ in Formula (2) is a hydrogen atom or group which has an ethylenically unsaturated bond. When n in formula (1) is 2 or more, (b) a plurality of R ⁴ contained in the hydroxyl group-containing modified unsaturated epoxy ester resin (in other words, a plurality of R ⁴ _{contained in [X] n} ) are all the same and some or all of them may be different.

Moreover, when R<^2> in Formula (1) is a hydrogen atom, [X] _n has at least 1 group which has an ethylenically unsaturated bond. Therefore, when R<^2> in Formula (1) is a hydrogen atom, at least 1 of one or some R<^4> in Formula (1) is group which has an ethylenically unsaturated bond. As group which has an ethylenically unsaturated bond used as R<^4> , the thing similar to what can be used as ^{R<2> in Formula (1) is mentioned.}

In addition, (b) hydroxyl group-containing modified unsaturated epoxy ester resin is a hydroxyl group-containing resin, so when R ² in formula (1) is a group having an ethylenically unsaturated bond, [X] _n has at least one hydroxyl group. Therefore, when R<^2> in Formula (1) is group which has an ethylenically unsaturated bond, ^{at least 1 of one or some R<4>} in Formula (1) is a hydrogen atom.

When X in Formula (1) is a thing represented by Formula (3), two R<^5> in Formula (3) is a hydrogen atom or a methyl group independently. When n in Formula (1) is 2 or more, ^{R 5} may be the same as all of some X which comprises _{[X] n} ^{, and some or all R 5} of some X may be different.

When X in Formula (1) is represented by Formula (3), R<^6> in Formula (3) is a hydrogen atom or group which has an ethylenically unsaturated bond. When n in Formula (1) is 2 or more, (b) a plurality of R ⁶ contained in the hydroxyl group-containing modified unsaturated epoxy ester resin (in other words, a plurality of R ⁶ _{contained in [X] n} ) are all the same and some or all of them may be different.

Moreover, when R<^2> in Formula (1) is a hydrogen atom, [X] _n has at least 1 group which has an ethylenically unsaturated bond. Therefore, when R<^2> in Formula (1) is a hydrogen atom, at least 1 of 1 or some R<^6> in Formula (1) is group which has an ethylenically unsaturated bond. As group which has an ethylenically unsaturated bond used as R<^6> , the thing similar to what can be used as ^{R<2> in Formula (1) is mentioned.}

In addition, (b) hydroxyl group-containing modified unsaturated epoxy ester resin is a hydroxyl group-containing resin, so when R ² in formula (1) is a group having an ethylenically unsaturated bond, [X] _n has at least one hydroxyl group. Therefore, when R<^2> in Formula (1) is group which has an ethylenically unsaturated bond, ^{at least 1 of 1 or some R<6>} in Formula (1) is a hydrogen atom.

((b) Method for producing a hydroxyl group-containing modified unsaturated epoxy ester resin)

(b) hydroxyl group-containing modified unsaturated epoxy ester resin of this embodiment can be manufactured by introduce|transducing an ethylenically unsaturated group into a part of secondary hydroxyl group in (b-1) unsaturated epoxy ester resin.

"(b-1) manufacturing method of unsaturated epoxy ester resin"

(b) The (b-1) unsaturated epoxy ester resin, which is a raw material of the hydroxyl group-containing modified unsaturated epoxy ester resin, contains 50 mol% or more of α,β-unsaturated monobasic acid with respect to the epoxy group of the (b-2) epoxy resin, preferably Preferably, it can be produced by a method of reacting by a known method in an amount of 80 mol% or more. In this embodiment, (b-1) the unreacted epoxy group which has not reacted with (alpha), (beta)- unsaturated monobasic acid among the epoxy groups which unsaturated epoxy ester resin has may remain.

(b-1) As the (b-2) epoxy resin used as a raw material of the unsaturated epoxy ester resin, a bisphenol type epoxy resin, a novolak type epoxy resin, a naphthol aralkyl type epoxy resin, a phenol aralkyl type epoxy resin, tetraphenylol An ethane-type epoxy resin, a cyclic aliphatic epoxy resin, triglycidyl isocyanurate, the epoxy resin etc. which introduce|transduced halogen atoms, such as a bromine atom, are mentioned.

As a bisphenol type of a bisphenol type epoxy resin, for example, biphenol, bisphenol A type, hydrogenated bisphenol A type, bisphenol F type, hydrogenated bisphenol F type, bisphenol S type, bisphenol SH type, bisphenol Z type, 4,4 Bisphenols, such as '-dihydroxybenzophenone, 2,4'-dihydroxybenzophenone, bis(4-hydroxyphenyl)fluorene, catechol, resorcinol, hydroquinone, dihydroxynaphthalene, tetrachloro Bisphenol A etc. are mentioned.

As a novolak-type of a novolak-type epoxy resin, a phenol novolak, a cresol novolak, a bisphenol A novolak, a dicyclopentadiene-phenol novolak, etc. are mentioned, for example.

As (b-2) epoxy resin used as a raw material of (b-1) unsaturated epoxy ester resin, it is preferable to use especially a bisphenol-type epoxy resin among the above-mentioned. It is preferable to use any 1 or more types especially chosen from bisphenol A type|mold, bisphenol F type|mold, hydrogenated bisphenol A type, and hydrogenated bisphenol F type|mold among bisphenol type epoxy resins.

(b) a hydroxyl group-containing modified unsaturated epoxy ester resin, which is a compound represented by Formula (1), wherein X in Formula (1) is represented by Formula (2), and R ³ in Formula (2) is a methyl group. In this case, it is preferable to use a bisphenol A epoxy resin as the (b-2) epoxy resin. (b) a hydroxyl group-containing modified unsaturated epoxy ester resin, which is a compound represented by Formula (1), wherein X in Formula (1) is represented by Formula (2), and R ³ in Formula (2) is a hydrogen atom. When manufacturing, it is preferable to use a bisphenol F-type epoxy resin as (b-2) epoxy resin.

(b) a hydroxyl group-containing modified unsaturated epoxy ester resin, which is a compound represented by Formula (1), wherein X in Formula (1) is represented by Formula (3), and R ⁵ in Formula (3) is a methyl group. When carrying out, it is preferable to use hydrogenated bisphenol A epoxy resin as (b-2) epoxy resin. (b) a hydroxyl group-containing modified unsaturated epoxy ester resin, which is a compound represented by Formula (1), wherein X in Formula (1) is represented by Formula (3), and R ⁵ in Formula (3) is a hydrogen atom. When manufacturing, it is preferable to use hydrogenated bisphenol F-type epoxy resin as (b-2) epoxy resin.

(b-1) Examples of the α,β-unsaturated monobasic acid used as a raw material for the unsaturated epoxy ester resin include (meth)acrylic acid, crotonic acid, cinnamic acid, and sorbic acid.

Among these ?,?-unsaturated monobasic acids, it is particularly preferable to use (meth)acrylic acid. (b) When producing the compound represented by Formula (1) as the hydroxyl group-containing modified unsaturated epoxy ester resin, it is preferable to use (meth)acrylic acid as the α,β-unsaturated monobasic acid.

(b-2) When reacting an epoxy resin with α,β-unsaturated monobasic acid to synthesize (b-1) unsaturated epoxy ester resin, a catalyst and/or a polymerization inhibitor may be used as needed. As a catalyst, conventionally well-known catalysts, such as a triphenylphosphine, can be used, for example. As a polymerization inhibitor, conventionally well-known polymerization inhibitors, such as methylhydroquinone, can be used, for example.

"(b-1) Modification method of unsaturated epoxy ester resin"

Next, an ethylenically unsaturated group is introduced into a part of the secondary hydroxyl group in the thus obtained (b-1) unsaturated epoxy ester resin and modified to prepare (b) a hydroxyl group-containing modified unsaturated epoxy ester resin.

(b-1) It does not specifically limit as a method of modifying|denaturing unsaturated epoxy ester resin, For example, the method of (I) or (II) shown below is mentioned.

(I) A method of reacting a part of secondary hydroxyl groups in an unsaturated epoxy ester resin with α,β-ethylenically unsaturated monoisocyanate.

(II) A method of adding an ethylenically unsaturated group-containing acid anhydride to a part of the secondary hydroxyl groups in the unsaturated epoxy ester resin.

(b) a hydroxyl group-containing modified unsaturated epoxy ester resin, for example, when producing a compound represented by the formula (1), the secondary hydroxyl group in the (b-1) unsaturated epoxy ester resin to introduce an ethylenically unsaturated group is the formula R<^2> in (1) may be couple|bonded only, and it may exist only in X in Formula (1), and both may be sufficient as it. When ^{producing a compound represented by the formula (1) in which R 2} in the formula (1) is a hydrogen atom, an ethylenically unsaturated group is introduced into at least one of the secondary hydroxyl groups present in X in the formula (1) .

「Method of (I)」

In the method of said (I), an ethylenically unsaturated group is introduce|transduced into a part of secondary hydroxyl group in an unsaturated epoxy ester resin using (alpha), beta -ethylenically unsaturated monoisocyanate. For this reason, in the method of said (I), a part of secondary hydroxyl group and an isocyanate group (-NCO) react, and a urethane bond (-NHCO-) is formed.

As the α,β-ethylenically unsaturated monoisocyanate used in the method (I) above, for example, (meth)acryloyl isocyanate, 2-isocyanatoethyl (meth)acrylate, 1,1-bis(meth) ) Acryloyloxymethylethyl isocyanate etc. are mentioned. These α,β-ethylenically unsaturated monoisocyanates may be used alone, or two or more thereof may be used.

As the α,β-ethylenically unsaturated monoisocyanate, among the above, the pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition has a remarkable decrease in adhesive strength due to light irradiation, so 2-isocyanatoethyl (meth)acryl Late and/or 1,1-bis(meth)acryloyloxymethylethylisocyanate are preferred.

In the method of said (I), as a method of adding (alpha), beta -ethylenically unsaturated monoisocyanate to a part of secondary hydroxyl group in an unsaturated epoxy ester resin, the method of a well-known urethanation reaction can be used. Specifically, for example, a method of reacting an unsaturated epoxy ester resin, α,β-ethylenically unsaturated monoisocyanate, and a urethanation catalyst to be used as needed in the presence of a solvent or in the absence of a solvent can be used.

As a urethanation catalyst, dibutyltin dilaurate, dioctyltin dilaurate, diazabicyclooctane (DABCO) etc. can be used, for example.

"Method of (II)"

In the method of said (II), an ethylenically unsaturated group is introduce|transduced into a part of secondary hydroxyl group in unsaturated epoxy ester resin using an ethylenically unsaturated group containing acid anhydride.

As an ethylenically unsaturated group containing acid anhydride used by the method of said (II), (meth)acrylic acid anhydride, etc. are mentioned. By using (meth)acrylic acid anhydride as the ethylenically unsaturated group-containing acid anhydride, (b) the pressure-sensitive adhesive composition containing the hydroxyl group-containing modified unsaturated epoxy ester resin has more excellent resistance to acid solutions and alkali solutions. Moreover, it is preferable to use (meth)acrylic acid anhydride from the point which can remove easily the liberated acrylic acid generated by reaction with an unsaturated epoxy ester resin in the subsequent drying process. These ethylenically unsaturated group containing acid anhydrides may be used individually by 1 type, and may be used 2 or more types.

It is preferable that mass ratio (a):(b) of (a) hydroxyl-containing (meth)acrylic resin and (b) hydroxyl-containing modified unsaturated epoxy ester resin in the adhesive composition of this embodiment is 60:40-40:60 and more preferably 55:45 to 45:55. When the mass ratio (a):(b) is 60:40 to 40:60, the pressure-sensitive adhesive sheet having the pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition is less likely to cause pressure-sensitive adhesive residue on the adherend after being peeled off, and the adherend and It becomes possible to more effectively prevent the intrusion of the processing liquid into the interface.

<(c) polyisocyanate compound>

The polyisocyanate compound (c) of the present embodiment is a polyisocyanate derived from an aliphatic diisocyanate. The aliphatic diisocyanate is a non-aromatic diisocyanate, and may be acyclic aliphatic diisocyanate or cyclic aliphatic diisocyanate.

(c) when the polyisocyanate compound is derived from an aliphatic diisocyanate, compared to the case where the polyisocyanate compound is derived from an aromatic diisocyanate, an adhesive composition capable of forming a pressure-sensitive adhesive layer having excellent resistance to acid and alkaline solutions is do. This is because aliphatic amides have lower desorption ability than aromatic amides, so (a) hydroxyl group-containing (meth)acrylic resins and (b) hydroxyl group-containing modified unsaturated epoxy ester resins, (c) urethane bonds formed through polyisocyanate compounds are difficult to decompose because it becomes

(c) As a polyisocyanate compound, the isocyanurate body which is a trimer of aliphatic diisocyanate, the aliphatic diisocyanate adduct with respect to polyhydric alcohol, etc. are mentioned, for example.

Specifically, an isocyanurate body of hexamethylene diisocyanate (hereinafter also referred to as “HDI”), which is a trimer of chain aliphatic diisocyanate, an HDI adduct of trimethylolpropane as a polyhydric alcohol, and cyclic aliphatic diisocyanate The isocyanurate body of isophorone diisocyanate which is a trimer of , etc. are mentioned. By using these (c) polyisocyanate compounds, the adhesive composition containing this becomes what has more outstanding tolerance with respect to an alkali solution.

In the adhesive composition of this embodiment, only 1 type (c) polyisocyanate compound may be contained and may be contained 2 or more types.

(c) Examples of the acyclic aliphatic diisocyanate used as a raw material for the polyisocyanate compound include diisocyanate having a chain aliphatic hydrocarbon in the molecule and not having an aromatic hydrocarbon. Specific examples thereof include butane diisocyanate, pentane diisocyanate, hexamethylene diisocyanate (HDI), trimethyl hexamethylene diisocyanate, and lysine diisocyanate.

Moreover, as a cyclic aliphatic diisocyanate used as a raw material of (c) a polyisocyanate compound, the diisocyanate which has a cyclic aliphatic hydrocarbon which does not have aromaticity in a molecule|numerator is mentioned. Specifically, isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, 1, 4- cyclohexane diisocyanate, etc. are mentioned, for example.

It is preferable that content of (c) polyisocyanate compound in an adhesive composition is 0.5-15 mass parts with respect to a total of 100 mass parts of (a) hydroxyl-containing acrylic resin and (b) hydroxyl-containing modified unsaturated epoxy ester resin, 1-10 It is more preferable that it is a mass part, and it is still more preferable that it is 2-6 mass parts. (c) When the usage-amount of polyisocyanate is 0.5 mass part or more, it becomes an adhesive composition which has more outstanding tolerance with respect to an acid solution and an alkali solution. (c) The wettability in the adhesive sheet which has an adhesive layer containing an adhesive composition as the usage-amount of polyisocyanate is 15 mass parts or less becomes favorable, and it will have high adhesive force with respect to a to-be-adhered body.

<(d) Photoinitiator>

The (d) photoinitiator in the present embodiment can be arbitrarily selected, for example, a carbonyl-based photopolymerization initiator, a sulfide-based photoinitiator, a quinone-based photoinitiator, an azo-based photopolymerization initiator, and a sulfochloride-based photoinitiator. A photoinitiator, a thioxanthone type photoinitiator, a peroxide type photoinitiator, etc. are mentioned.

In the adhesive composition of this embodiment, only 1 type (d) photoinitiator may be contained and may be contained 2 or more types.

Examples of the carbonyl-based photopolymerization initiator include benzophenone, benzyl, benzoin, ω-bromoacetophenone, chloroacetone, acetophenone, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2- Phenylacetophenone, 2,2-dimethoxy-1,2-diphenylethan-1-onebenzyl, p-dimethylaminoacetophenone, p-dimethylaminopropiophenone, 2-chlorobenzophenone, p,p'- Dichlorobenzophenone, p,p'-bisdiethylaminobenzophenone, Michler ketone, benzoin methyl ether, benzoin isobutyl ether, benzoin-n-butyl ether, benzylmethyl ketal, 1-hydroxycyclohexylphenyl Ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, methylbenzoylformate, 2 and 2-diethoxyacetophenone, 4-N,N'-dimethylacetophenone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, and the like. .

Examples of the sulfide-based photopolymerization initiator include diphenyldisulfide, dibenzyldisulfide, tetraethylthiuramdisulfide, and tetramethylammonium monosulfide.

As a quinone type photoinitiator, benzoquinone, anthraquinone, etc. are mentioned, for example.

As an azo photoinitiator, azobisisobutyronitrile, 2,2'- azobispropane, hydrazine etc. are mentioned, for example.

As a thioxanthone type photoinitiator, thioxanthone, 2-chlorothioxanthone, or 2-methylthioxanthone etc. are mentioned, for example.

As a peroxide type photoinitiator, benzoyl peroxide, di-t- butyl peroxide, etc. are mentioned, for example.

(d) As a photoinitiator, from the soluble point in an adhesive composition, 2,2-dimethoxy-1,2-diphenylethane-1-onebenzyl, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy It is preferable to use any one or more selected from oxy-2-methyl-1-phenylpropan-1-one.

Content of (d) photoinitiator in adhesive composition is 0.1-5 mass parts with respect to a total of 100 mass parts of (a) hydroxyl-containing (meth)acrylic resin and (b) hydroxyl-containing modified unsaturated epoxy ester resin in the range desirable. 0.1-0.5 mass parts, 0.5-1.5 mass parts, 1.0-3.0 mass parts, or 2.0-5.0 mass parts etc. may be sufficient as needed. (d) when the amount of the photopolymerization initiator used is 0.1 parts by mass or more, the curing rate and the rate of decrease of the adhesive force by light irradiation to the pressure-sensitive adhesive sheet having the pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition are accelerated, and the pressure-sensitive adhesive sheet It is possible to more effectively prevent the adhesive from remaining on the later adherend. (d) After peeling the adhesive sheet which has an adhesive layer containing an adhesive composition as the usage-amount of a photoinitiator is 5 mass parts or less, it can suppress that (d) photoinitiator remains on the to-be-adhered body surface.

The pressure-sensitive adhesive composition of the present embodiment contains (a) a hydroxyl group-containing (meth)acrylic resin, (b) a modified epoxy ester resin, (c) a polyisocyanate compound, and (d) a photopolymerization initiator. Therefore, you may contain a tackifier, various additives, and an organic solvent.

As a tackifier, a conventionally well-known thing can be used without limitation in particular. For example, terpene type tackifying resin, phenol type tackifying resin, rosin type tackifying resin, aliphatic type petroleum resin, aromatic type petroleum resin, copolymer type petroleum resin, alicyclic type petroleum resin, xylene resin, epoxy type tackifying resin , polyamide type tackifying resin, ketone type tackifying resin, elastomer type tackifying resin, etc. are mentioned. These tackifiers may be used individually by 1 type, and may be used in combination of 2 or more type.

When an adhesive composition contains a tackifier, it is preferable that the usage-amount shall be 30 mass parts or less with respect to 100 mass parts of (a) hydroxyl group containing (meth)acrylic resin.

Additives can be arbitrarily selected, and include plasticizers, surface lubricants, leveling agents, softeners, antioxidants, anti-aging agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, light stabilizers such as benzotriazoles, phosphoric acid esters and other flame retardants, interfaces antistatic agents such as activators; and the like.

An organic solvent can be used as a diluent in viscosity adjustment at the time of coating an adhesive composition.

The organic solvent can be arbitrarily selected, for example, methyl ethyl ketone, methyl isobutyl ketone, acetone, ethyl acetate, n-propyl acetate, tetrahydrofuran, dioxane, cyclohexanone, n-hexane, toluene, xylene, n -propanol, isopropanol, etc. are mentioned. These organic solvents may be used individually by 1 type, and may mix and use 2 or more types.

(Method for producing pressure-sensitive adhesive composition)

The adhesive composition of this embodiment contains (a) hydroxyl group containing (meth)acrylic resin, (b) modified epoxy ester resin, (c) polyisocyanate compound, (d) photoinitiator, and further, as needed It can manufacture by the method of mixing and stirring any 1 or more types of the tackifier used, various additives, and an organic solvent by a well-known method.

When an adhesive composition contains an organic solvent, you may use the solvent used when manufacturing each component which comprises an adhesive composition as an organic solvent as it is.

[adhesive sheet]

In the adhesive sheet of this embodiment, the adhesive layer is provided on one side of a base material.

(materials)

The adhesive sheet of this embodiment has a base material, Preferably, it has a sheet-like or film-form base material. As the material of the base material, a known material can be appropriately selected and used. As the base material, it is preferable to use a transparent base material, for example, a resin sheet made of a transparent resin material so that light irradiation to the pressure-sensitive adhesive sheet can be performed from the base material side.

Examples of the resin material include polyolefins such as polyethylene (PE) and polypropylene (PP); polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate; polyvinyl chloride (PVC); polyimide (PI); polyphenylene sulfide (PPS); ethylene vinyl acetate (EVA); Polytetrafluoroethylene (PTFE), etc. are mentioned. Among these resin materials, it is preferable to use at least one selected from PE, PP, and PET, since a pressure-sensitive adhesive sheet having particularly suitable flexibility can be obtained. The number of resin materials used for a base material may be one, and 2 or more types may be mixed and used for them.

When using a resin sheet as a base material, a single layer may be sufficient as a resin sheet, and the multilayer structure (for example, three-layer structure) of two or more layers may be sufficient as it. In the resin sheet which has a multilayer structure, the resin material which comprises each layer may be a resin material containing only 1 type individually, and the resin material containing 2 or more types may be sufficient as it.

When a resin sheet is used as the base material, it can be manufactured by appropriately employing a conventionally known general sheet molding method (eg, extrusion molding, T-die molding, inflation molding, or uniaxial or biaxial stretching molding, etc.).

The thickness of the substrate can be appropriately selected according to the use of the pressure-sensitive adhesive sheet, the material of the substrate, and the like. When using a resin sheet as a base material, it is preferable that it is 10-1000 micrometers, and, as for the thickness of a base material, it is more preferable that it is 50-300 micrometers. The rigidity (elasticity) of an adhesive sheet becomes it high that the thickness of a base material is 10 micrometers or more. Therefore, when affixing an adhesive sheet to a to-be-adhered body, there exists a tendency for it to become difficult to generate|occur|produce wrinkles in an adhesive sheet, or to generate|occur|produce between an adhesive sheet and a to-be-adhered body. Moreover, swelling penetration (immersion) of the processing liquid from the surface of an adhesive sheet as the thickness of a base material is 10 micrometers or more can be suppressed. Moreover, when the thickness of a base material is 10 micrometers or more, it becomes easy to peel the adhesive sheet affixed to a to-be-adhered body from a to-be-adhered body, and workability|operativity (handling property, handling) becomes favorable. When the thickness of the base material is 1000 µm or less, the pressure-sensitive adhesive sheet has moderate flexibility and workability becomes good.

In order to improve the adhesiveness of a base material and an adhesive layer, the surface treatment (process for obtaining anchoring property of an adhesive) may be given to the surface of the side on which the adhesive layer of a base material is provided.

As surface treatment, corona discharge treatment, acid treatment, ultraviolet irradiation treatment, plasma treatment, primer (primer) application|coating etc. are mentioned, for example.

(Adhesive layer)

The adhesive layer of the adhesive sheet of this embodiment contains the adhesive composition of this embodiment, and it is preferable that only the adhesive composition of this embodiment is included.

Although the thickness of an adhesive layer can be selected arbitrarily, it is preferable to set it as 1-100 micrometers, It is more preferable to set it as 2-80 micrometers, It is still more preferable to set it as 5-50 micrometers. If the thickness of an adhesive layer is 1 micrometer or more, an adhesive layer with a uniform thickness can be formed with high precision. When the thickness of the pressure-sensitive adhesive layer is 100 µm or less, it is difficult to cause a problem of odor due to the solvent remaining in the pressure-sensitive adhesive layer, and it is preferable.

(Releasable sheet)

The adhesive sheet of this embodiment may have a peeling sheet (separator) on the adhesive surface of an adhesive sheet, ie, the surface on the opposite side to the base material of an adhesive layer. By having the release sheet, it is possible to protect the pressure-sensitive adhesive surface (the surface of the pressure-sensitive adhesive layer) of the pressure-sensitive adhesive sheet until just before it is adhered to the adherend. Moreover, at the time of use of an adhesive sheet, the peeling sheet is peeled, an adhesive layer (adhesive surface) is exposed, and the operation|work of pressure-bonding to a to-be-adhered body can be performed efficiently.

As the material of the release sheet, a known material can be appropriately selected and used. For example, as a material of a release sheet, the resin sheet used as a base material can be used.

The thickness of the release sheet can be appropriately selected according to the use of the pressure-sensitive adhesive sheet, the material of the release sheet, and the like. When using a resin sheet as a release sheet, it is preferable that the thickness of a release sheet is 5-300 micrometers, for example, More preferably, it is 10-200 micrometers, More preferably, it is 25-100 micrometers.

A peeling process may be performed to the peeling surface (surface arrange|positioned in contact with an adhesive layer) of a peeling sheet using conventionally well-known release agents, such as a silicone type, a long-chain alkyl type, and a fluorine type, as needed.

(Method for Producing Adhesive Sheet)

The adhesive sheet of this embodiment can be manufactured by the method shown below, for example.

On a base material, an adhesive composition is apply|coated so that it may become a predetermined|prescribed film thickness. Next, an adhesive layer is formed by heat-drying and hardening the apply|coated adhesive composition.

A well-known method can be used as a coating method of an adhesive composition. Specifically, a method of applying using an applicator and a conventional coater, for example, a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, a spray coater, a comma coater, a direct coater, etc. can be heard

In addition, after forming an adhesive layer by an above-mentioned method on separators, such as a peeling film, you may form an adhesive layer on a base material by the method of transferring (transferring) an adhesive layer on a base material. In addition, in this case, although the separator is removed later, you may use it as a peeling sheet as it is as needed.

Next, on the pressure-sensitive adhesive layer formed on the substrate, that is, on the exposed surface of the pressure-sensitive adhesive layer, a release sheet is laminated and bonded. Thereby, the adhesive sheet in which the base material, the adhesive layer, and the peeling sheet were laminated|stacked in this order is obtained.

The pressure-sensitive adhesive sheet of the present embodiment may have a predetermined shape according to the shape of the adherend by a punching method or the like.

(How to use the adhesive sheet)

When an adhesive sheet has a peeling sheet, the peeling sheet is peeled at the time of use, and an adhesive layer (adhesive side) is exposed. Next, the exposed pressure-sensitive adhesive layer is placed opposite to the adherend and pressed. Thereby, an adhesive sheet and a to-be-adhered body are made to adhere. In this state, for example, the adherend is subjected to a pretreatment of plating treatment. And in the step where the pressure-sensitive adhesive sheet becomes unnecessary, the pressure-sensitive adhesive sheet is irradiated with light, preferably light from the substrate side to lower the adhesive strength of the pressure-sensitive adhesive sheet, and the pressure-sensitive adhesive sheet is peeled from the adherend.

Although it can select arbitrarily as needed as the light irradiated to an adhesive sheet, it is preferable to use ultraviolet-ray (UV). Examples of the light source used when performing UV irradiation include a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a chemical lamp, a black light, a light emitting diode (LED), and the like. It is preferable to use a mercury lamp or a metal halide lamp.

When using a high-pressure mercury lamp, it is preferable that it is 50-3000 mJ/cm<2>, and, as for the irradiation amount of UV with respect to an adhesive sheet, it is more preferable that it is 100-600 mJ/cm<2>. The effect of reducing the adhesive force of the adhesive sheet by UV irradiation as UV irradiation amount irradiated to an adhesive sheet is 50 mJ/cm<2> or more is fully acquired. Specifically, the pressure-sensitive adhesive layer is photocured at a sufficiently fast curing rate, the elastic modulus is increased, and the adhesive force of the pressure-sensitive adhesive layer to the adherend is sufficiently reduced. Even if the UV irradiation amount irradiated to the pressure-sensitive adhesive sheet is 3000 mJ/cm 2 or more, the corresponding lowering effect of the adhesive strength of the pressure-sensitive adhesive layer is not obtained.

The adhesive sheet of this embodiment is provided with the adhesive layer containing the adhesive composition of this embodiment on one side of a base material. For this reason, the adhesive layer of the adhesive sheet of this embodiment has excellent tolerance with respect to an acid solution and an alkali solution, and can suppress the penetration|invasion of the processing liquid to the interface with a to-be-adhered body. Therefore, by affixing the adhesive sheet of this embodiment to a to-be-adhered body and surface-treating, it can prevent that the part of to-be-adhered body which surface treatment is unnecessary is processed. Moreover, the adhesive force of the adhesive layer falls by irradiating the adhesive sheet of this embodiment with light after affixing to the to-be-adhered body, and it is hard to produce adhesive residue on the surface of the to-be-adhered body which peeled the adhesive sheet.

Therefore, the adhesive sheet of this embodiment can be used suitably as a mask which protects the surface of a to-be-adhered body. As a to-be-adhered body protected by the adhesive sheet of this embodiment, the thing containing glass or a metal can be used suitably, for example. As a to-be-adhered body containing a metal, a stainless steel (SUS) plate, an aluminum plate, a copper plate, etc. are mentioned, for example.

The pressure-sensitive adhesive sheet of the present embodiment is specifically etched with an etchant such as a hydrofluoric acid solution (erosion polishing treatment), or a pretreatment (degreasing treatment) of a plating treatment using an acidic solution and an alkaline solution, for example, glass or metal It can be suitably used as a sheet for protecting the portion to be protected from the treatment liquid among the surface of the adherend containing

As an acidic solution, the liquid mixture containing 1 type(s) or 2 or more types chosen from hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and hydrofluoric acid, etc. are mentioned. Among these acidic solutions, a hydrofluoric acid solution is preferably used for etching the cut surface of a glass plate. As an acidic solution, a thing of pH 1 or less can be used. As an alkaline solution, potassium hydroxide, sodium hydroxide, etc. can be used.

Example

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited by these examples at all. Note that, in the following description, "%" and "parts" are based on mass unless otherwise specified.

<Acrylic resin (A-1)>

130 parts of ethyl acetate as a raw material monomer and a solvent were put into a reaction apparatus equipped with a stirrer, a temperature controller, a reflux condenser, a dropping funnel, and a thermometer, heating reflux was started, and 0.1 parts of azobisisobutyronitrile was added as a polymerization initiator. Thereafter, the reaction was carried out at reflux temperature of ethyl acetate for 3 hours. As raw material monomers, 80 parts of n-butyl acrylate, 60 parts of ethyl acrylate, 6.3 parts of methyl methacrylate, 1 part of acrylic acid, and 0.8 part of 2-hydroxyethyl acrylate were used.

What dissolved 0.1 part of azobisisobutyronitrile in 4 parts of toluene as a solvent was added to the reaction liquid made to react for 3 hours, and it was made to react at reflux temperature for further 4 hours. Thereafter, by diluting with toluene, an acrylic resin (A-1) solution having a resin content of 40% was obtained.

The weight average molecular weight (Mw), glass transition temperature (Tg), hydroxyl value, and acid value of the acrylic resin (A-1) in the acrylic resin (A-1) solution were measured by the method shown below. As a result, the weight average molecular weight (Mw) of the acrylic resin (A-1) was 550,000, the glass transition temperature (Tg) was -35.2 degreeC, the hydroxyl value was 3 mgKOH/g, and the acid value was 5 mgKOH/g.

(weight average molecular weight (Mw))

It was measured at room temperature under the following conditions using gel permeation chromatography (Showa Denko Co., Ltd. make, Shodex (trademark) GPC-101), and calculated in terms of polystyrene.

Column: Showa Denko Co., Ltd., Shodex (registered trademark) LF-804

Column temperature: 40°C

Sample: 0.2 mass % tetrahydrofuran solution of acrylic resin (A-1)

Flow: 1ml/min

Eluent: tetrahydrofuran

(Glass Transition Temperature (Tg))

It measured using the differential scanning calorimeter (The Hitachi High-tech Science company make, DSC7000X).

Specifically, 1 g was collected from the acrylic resin (A-1) solution, dried at 100°C for 10 minutes, the solvent was volatilized, and the solid content was obtained. A 10 mg sample was collected from the obtained solid content. Then, using a differential scanning calorimeter (DSC), the temperature of the sample was changed from -80°C to 200°C at a temperature increase rate of 10°C/min to perform differential scanning calorimetry, and the observed endothermic onset temperature by the glass transition was liberated It was set as the transition temperature (Tg). In addition, when two Tgs were observed, it was set as the average value of two Tgs.

(hydroxyl value)

(a) The hydroxyl value of the (meth)acrylic resin containing a hydroxyl group is the hydroxyl value measured according to JISK0070. The hydroxyl value means the number of mg of potassium hydroxide required to neutralize free acetic acid when 1 g of resin is acetylated. Specifically, the hydroxy group in the sample was acetylated using acetic anhydride, and the resulting free acetic acid was titrated with a potassium hydroxide solution.

(acid number)

(a) The acid value of the (meth)acrylic resin containing a hydroxyl group was measured according to JIS K6901 5.3.2, using a mixture indicator of bromothymol blue and phenol red. An acid value means the number of mg of potassium hydroxide required to neutralize the acidic component contained in resin 1g.

<Acrylic resin (A-2)>

130 parts of ethyl acetate as a raw material monomer and a solvent were thrown into the reaction apparatus equipped with a stirrer, a temperature controller, a reflux condenser, a dropping funnel, and a thermometer, and heating reflux was started. Then, 0.2 part of azobisisobutyronitrile was added as a polymerization initiator, and it was made to react at ethyl acetate reflux temperature for 8 hours. Then, the acrylic resin (A-2) whose resin content is 40% was obtained by diluting with toluene. As raw material monomers, 55 parts of n-butyl acrylate, 85 parts of methyl acrylate, 5.8 parts of methyl methacrylate, 1 part of acrylic acid, and 1.5 parts of 2-hydroxyethyl acrylate were used.

About the acrylic resin (A-2), it carried out similarly to the acrylic resin (A-1), and measured the weight average molecular weight (Mw), a glass transition temperature (Tg), a hydroxyl value, and an acid value. As a result, the weight average molecular weight (Mw) of the acrylic resin (A-2) was 610,000, the glass transition temperature (Tg) was -15.2 degreeC, the hydroxyl value was 5 mgKOH/g, and the acid value was 5 mgKOH/g.

<Hydroxy group-containing modified unsaturated epoxy ester resin (B-1)>

A bisphenol A epoxy resin (manufactured by Asahi Chemical Co., Ltd., trade name Araldite AER2603, epoxy equivalent 189) 100 parts (molar number of epoxy groups 0.53 mol) to a reactor equipped with a stirrer, temperature controller, reflux condenser, dropping funnel, and thermometer And, 38 parts of acrylic acid (0.53 moles of moles of carboxyl groups) as an α,β-unsaturated monobasic acid, 0.6 parts of triphenylphosphine as a catalyst, and 0.12 parts of methylhydroquinone as a polymerization inhibitor are added, and at 120° C. while blowing air Reaction was continued for 8 hours, and unsaturated epoxy ester resin was obtained.

Lower the temperature of the reaction solution containing the unsaturated epoxy ester resin to 60 ° C., and through a dropping funnel, α,β-ethylenically unsaturated monoisocyanate 2-isocyanatoethyl methacrylate (manufactured by Showa Denko Co., Ltd., trade name) A mixture of 49 parts of Karenz MOI (registered trademark)) (0.32 moles of moles of isocyanate groups) and 0.02 parts of dibutyltin dilaurate, which is a urethanization catalyst, was added dropwise. The reaction liquid after completion|finish of dripping was hold|maintained at 70 degreeC for 4 hours, and the isocyanato group in the reaction liquid was lose|disappeared.

α,β- with respect to the total number of moles of the number of α,β-unsaturated monobasic acid groups and the number of epoxy groups bonded to a primary carbon atom derived from an epoxy group, which is a compound represented by formula (1) by the above steps A modified epoxy ester resin (B-1) having a weight average molecular weight of 1300 in which the ratio of the unsaturated monobasic acid group is 100 mol% was obtained.

In modified epoxy ester resin (B-1), two R<^1> in Formula (1) is a hydrogen atom. ^{R 2} in Formula (1) is CH ₂ =C(CH ₃ )COOCH ₂ CH ₂ -NHCO-. X in Formula (1) is represented by Formula (2). ^{Two R<3>} in Formula (2) is a methyl group. n is 1 or 2. That is, the modified epoxy ester resin (B-1) is a mixture of a resin in which n is 1 and a resin in which n is 2. When n is 1, R ⁴ is a hydrogen atom. when n is 2, X is a second species, the formula (1) are the two R ⁴ either is a hydrogen atom, the other of the _{CH 2 = C (CH 3)} COOCH 2 CH 2 -NHCO-.

The weight average molecular weight of the modified epoxy ester resin (B-1) was measured in the same manner as for the acrylic resin (A-1).

In addition, with respect to the unsaturated epoxy ester resin produced during the production of the modified epoxy ester resin (B-1) and the modified epoxy ester resin (B-1), the number of moles of hydroxyl groups in the resin is determined by the neutralization titration method of JIS K 0070, respectively. did. As a result, the number of moles of the hydroxyl groups in the modified epoxy ester resin (B-1) was 0.24 moles, and the number of moles of the hydroxyl groups in the unsaturated epoxy ester resin was 0.56 moles.

In addition, the hydroxyl value of modified epoxy ester resin (B-1) was carried out similarly to acrylic resin (A-1), and it measured. As a result, it was 74 mgKOH/g.

<Hydroxy group-containing modified unsaturated epoxy ester resin (B-2)>

100 parts (number of moles of epoxy group) hydrogenated bisphenol A epoxy resin (manufactured by Shin-Nittetsu Chemical Co., Ltd., trade name ST-3000, epoxy equivalent 230) to a reactor equipped with a stirrer, temperature controller, reflux condenser, dropping funnel, and thermometer 0.43 mol), 31 parts of acrylic acid (the number of moles of carboxyl groups 0.43 mol) as an α,β-unsaturated monobasic acid, 0.4 parts of triphenylphosphine as a catalyst, and 0.08 parts of methylhydroquinone as a polymerization inhibitor, while blowing air The reaction was continued at 120 degreeC for 8 hours, and the unsaturated epoxy ester resin was obtained.

Lower the temperature of the reaction solution containing the unsaturated epoxy ester resin to 60 ° C., and through a dropping funnel, α,β-ethylenically unsaturated monoisocyanate 2-isocyanatoethyl methacrylate (manufactured by Showa Denko Co., Ltd., A mixed solution of 45 parts (trade name: Karenz MOI (registered trademark)) (0.29 mol of moles of isocyanate groups) and 0.02 parts of dibutyltin dilaurate as a urethanization catalyst was added dropwise. The reaction liquid after completion|finish of dripping was hold|maintained at 70 degreeC for 4 hours, and the isocyanato group in the reaction liquid was lose|disappeared.

α,β- with respect to the total number of moles of the number of α,β-unsaturated monobasic acid groups and the number of epoxy groups bonded to a primary carbon atom derived from an epoxy group, which is a compound represented by formula (1) by the above steps A modified epoxy ester resin (B-2) having a weight average molecular weight of 1400 in which the proportion of the unsaturated monobasic acid group was 100 mol% was obtained.

In modified epoxy ester resin (B-2), two R<^1> in Formula (1) is a hydrogen atom. ^{R 2} in Formula (1) is CH ₂ =C(CH ₃ )COOCH ₂ CH ₂ -NHCO-. X in Formula (1) is represented by Formula (3). ^{Two R<5>} in Formula (3) is a methyl group. n is 1 or 2. That is, the modified epoxy ester resin (B-2) is a mixture of a resin in which n is 1 and a resin in which n is 2. When n is 1, R ⁶ is a hydrogen atom. when n is 2, X is a second species, the formula (1) are the two R ⁶ is one of a hydrogen atom, the other of the _{CH 2 = C (CH 3)} COOCH 2 CH 2 -NHCO-.

The weight average molecular weight of the modified epoxy ester resin (B-2) was measured in the same manner as for the acrylic resin (A-1).

In addition, with respect to the unsaturated epoxy ester resin produced during the production of the modified epoxy ester resin (B-2) and the modified epoxy ester resin (B-2), the number of moles of hydroxyl groups in the resin is determined by the neutralization titration method of JIS K 0070, respectively. did. As a result, the mole number of hydroxyl groups in the modified epoxy ester resin (B-2) was 0.23 moles, and the mole number of hydroxyl groups in the unsaturated epoxy ester resin was 0.52 moles.

In addition, the hydroxyl value of modified|denatured epoxy ester resin (B-2) was carried out similarly to acrylic resin (A-1), and it measured. As a result, it was 84 mgKOH/g.

<Hydroxy group-containing modified unsaturated epoxy ester resin (B-3)>

It carried out similarly to modified|denatured epoxy ester resin (B-1), and obtained the reaction liquid containing unsaturated epoxy ester resin.

The temperature of the reaction solution containing the unsaturated epoxy ester resin was raised to 130° C., and through a dropping funnel, 49 parts of methacrylic anhydride, an acid anhydride containing an ethylenically unsaturated group (manufactured by Evonik Degusa Japan Co., Ltd., trade name MAAH) (0.32 mol) and the mixed liquid of 0.4 part of triphenylphosphine which is a catalyst were dripped. The reaction liquid after completion|finish of dripping was hold|maintained at 130 degreeC for 2 hours, and the acid anhydride in the reaction liquid was lose|disappeared. After that, the water washing process, the toluene washing process, and the vacuum dehydration process were sequentially performed.

α,β- with respect to the total number of moles of the number of α,β-unsaturated monobasic acid groups and the number of epoxy groups bonded to a primary carbon atom derived from an epoxy group, which is a compound represented by formula (1) by the above steps A modified epoxy ester resin (B-3) having a weight average molecular weight of 1100 in which the proportion of the unsaturated monobasic acid group was 100 mol% was obtained.

In modified epoxy ester resin (B-3), two R<^1> in Formula (1) is a hydrogen atom. ^{R 2} in Formula (1) is a methacryloyl group. X in Formula (1) is represented by Formula (2). ^{Two R<3>} in Formula (2) is a methyl group. n is 1 or 2. That is, the modified epoxy ester resin (B-3) is a mixture of a resin in which n is 1 and a resin in which n is 2. When n is 1, R ⁴ is a hydrogen atom. When n is 2, X is 2 types, ^{one of two R<4>} in Formula (1) is a hydrogen atom, and the other is a methacryloyl group.

The weight average molecular weight of the modified epoxy ester resin (B-3) was measured in the same manner as for the acrylic resin (A-1).

Moreover, about the modified epoxy ester resin (B-3), the number of moles of the hydroxyl group in resin was calculated|required by the neutralization titration method of JISK0070. As a result, the number of moles of the hydroxyl groups in the modified epoxy ester resin (B-3) was 0.21 moles.

In addition, the hydroxyl value of modified epoxy ester resin (B-3) was carried out similarly to acrylic resin (A-1), and it measured. As a result, it was 80 mgKOH/g.

(Example 1)

(a) hydroxyl group-containing (meth)acrylic resin, (b) hydroxyl group-containing modified unsaturated epoxy ester resin, (c) polyisocyanate compound, and (d) A photoinitiator was added in the ratio shown in Table 1, mixed and stirred, and the adhesive composition of Example 1 was obtained.

Next, on a substrate containing a polyethylene terephthalate (PET) film having a thickness of 50 μm, the pressure-sensitive adhesive composition of Example 1 is coated so that the film thickness after drying is 20 μm, and heat-dried at 105° C. for 2 minutes to dry the pressure-sensitive adhesive layer was formed. Then, on the adhesive layer, the release sheet containing the same PET film as a base material was bonded together, and the adhesive sheet of Example 1 was obtained.

(Examples 2 to 9, Comparative Examples 1 to 3)

Except having used the raw material shown in Table 1 or Table 2 in the ratio shown in Table 1 or Table 2, it carried out similarly to Example 1, and obtained the adhesive composition of Examples 2-9 and Comparative Examples 1-3.

And except having used the adhesive composition of Examples 2-9 and Comparative Examples 1-3, it carried out similarly to Example 1, and obtained the adhesive sheet of Examples 2-9 and Comparative Examples 1-3.

The following symbols described in Tables 1 and 2 are compounds shown below.

"VR-77" Bisphenol A type epoxy acrylate (manufactured by Showa Denko Co., Ltd.)

"DPHA" dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., trade name KAYARAD)

"Coronate (trademark) HL" 75% ethyl acetate solution of hexamethylene diisocyanate (HDI) adduct of trimethylolpropane (manufactured by Tosoh Corporation)

"Coronate (trademark) HX" isocyanurate form of hexamethylene diisocyanate (HDI) (manufactured by Tosoh Corporation)

"Desmodure Z-4470BA" isocyanurate form of isophorone diisocyanate (manufactured by Sumika Kovestro Urethane Co., Ltd.)

"Coronate L" tolylene diisocyanate adduct (manufactured by Tosoh Corporation)

"Irgacure 184" 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by BASF)

The numerical values of (a) hydroxyl group-containing (meth)acrylic resins (A-1) and (A-2) in Tables 1 and 2 are (meth)acrylic resins (A-1) and (A-2) as solid content. content (mass %). The solid content in (meth)acrylic resin (A-1) and (A-2) was measured by the following method.

The numerical values of (c) polyisocyanate compound and (d) photoinitiator in Tables 1 and 2 are, respectively, (a) the solid content of the hydroxyl group-containing (meth)acrylic resin and (b) the hydroxyl group-containing modified unsaturated epoxy ester resin (Comparative Example) In 3, it is content (mass part) with respect to a total of 100 mass parts of polyfunctional acrylate).

<Solid content>

2 g of (meth)acrylic resins (A-1) and (A-2) were respectively weighed, and after drying this at 110 degreeC in air for 5 hours, it weighed again. And it calculated|required from the following formula using the mass before drying and the mass after drying.

In addition, both solid content in (meth)acrylic resin (A-1) and (A-2) is considered to be a copolymer.

Solid content (%) = [A/B] × 100

A: mass after drying

B: mass before drying

Next, with respect to the adhesive sheets of Examples 1 to 9 and Comparative Examples 1 to 3, the adhesive force before and after UV irradiation, adhesive residue, and treatment liquid penetration were evaluated by the methods shown below, respectively. The results are shown in Table 1.

(How to prepare the sample before UV irradiation)

The pressure-sensitive adhesive sheet was cut into a size of 25 mm in length and 100 mm in width, and then the release sheet was peeled off to expose the pressure-sensitive adhesive layer. Next, the pressure-sensitive adhesive sheet was affixed to the glass plate so that the exposed pressure-sensitive adhesive layer (measurement surface) was in contact with the glass plate, and a 2 kg rubber roller (width: about 50 mm) was reciprocated to obtain a sample before UV irradiation.

(Measurement of adhesion of sample before UV irradiation)

The sample before UV irradiation was left to stand in the environment of 23 degreeC, humidity 50%RH for 24 hours. Then, according to JIS Z0237, the tensile test of the 180 degree direction was done at the peeling rate of 300 mm/min, and the adhesive force (N/25 mm) between a glass plate and an adhesive sheet was measured.

(Production method of sample after UV irradiation)

The sample before UV irradiation was left to stand in the environment of 23 degreeC, humidity 50%RH for 24 hours. Thereafter, the substrate side was subjected to UV irradiation using a high-pressure mercury lamp under the condition of a UV irradiation amount of 500 mJ/cm 2 , and samples were obtained after UV irradiation.

(Measurement of adhesion of sample after UV irradiation)

About the sample after UV irradiation, according to JIS Z0237, the 180 degree direction tensile test was done at the peeling rate of 300 mm/min, and the adhesive force (N/25 mm) between a glass plate and an adhesive sheet was measured.

(Evaluation of adhesive residue)

The adhesive sheet was peeled from the sample after said UV irradiation, and it confirmed visually whether the adhesive remained on a glass plate, and evaluated by the reference|standard shown below.

○ (Good): No adhesive remains on the adherend.

Δ (possible): The adhesive remains on a part of the adherend.

x (impossible): The adhesive remains on the whole surface of a to-be-adhered body.

(Evaluation of invasiveness of treatment solution)

The above-mentioned sample before UV irradiation was immersed in the acidic treatment liquid shown below for 10 minutes. Then, it was further immersed in the alkaline treatment liquid shown below for 10 minutes. Then, the sample before UV irradiation immersed in the acidic treatment liquid and the alkaline treatment liquid was visually observed from the surface of the pressure-sensitive adhesive sheet, and the penetration of the treatment liquid between the pressure-sensitive adhesive sheet and the glass plate was evaluated according to the standards shown below.

○ (Good): Intrusion of the treatment liquid was not observed.

△ (possible): Intrusion of the treatment liquid is seen in some parts.

x (impossible): Intrusion of a processing liquid was seen in the whole interface.

"Acid treatment liquid"

A mixed aqueous solution of pH 1 or less containing hydrofluoric acid, sulfuric acid, nitric acid and phosphoric acid

"Alkaline treatment liquid"

KOH 1mol/L

As shown in Table 1, the adhesive sheets of Examples 1 to 9 had an adhesive force before UV irradiation of 13.0 N/25 mm or more, and had a sufficiently high adhesive force before UV irradiation. Moreover, in the adhesive sheet of Examples 1-9, the adhesive force after UV irradiation was less than 1.0 N/25 mm, and the adhesive force after UV irradiation was a thing low enough.

In the adhesive sheets of Examples 1 to 9, evaluation of adhesive residual and processing liquid penetration property was "○ (good)" or "Δ (possible)".

On the other hand, as shown in Table 2, in Comparative Example 1 using (c) a polyisocyanate derived from an aromatic diisocyanate (tolylene diisocyanate adduct) as the polyisocyanate compound, the evaluation of the penetration of the treatment liquid was "x (impossible)" ' was.

Further, (b) in Comparative Example 2 in which an unsaturated epoxy ester resin not modified with an ethylenically unsaturated group (bisphenol A epoxy acrylate) was used instead of the hydroxyl group-containing modified unsaturated epoxy ester resin, the adhesive strength after UV irradiation was high, and the treatment liquid The evaluation of invasiveness was "x (impossibility)". It is estimated that this is for the reason shown below.

In the unsaturated epoxy ester resin which is not modified|denatured by the ethylenically unsaturated group, compared with (b) hydroxyl-group containing modified|denatured unsaturated epoxy ester resin, many hydroxyl groups exist. The excess hydroxyl group in the unsaturated epoxy ester resin which is not modified|denatured by the ethylenically unsaturated group reduces water resistance in the adhesive sheet using the adhesive composition containing this. For this reason, it becomes easy to impregnate an acidic treatment liquid. As a result, in Comparative Example 2, it is estimated that the evaluation of the invasiveness of the treatment liquid was "x (impossible)".

In addition, (b) in Comparative Example 3 using a polyfunctional acrylate (dipentaerythritol hexaacrylate) instead of a hydroxyl group-containing modified unsaturated epoxy ester resin, compared with Examples 1 to 9, the adhesive strength before UV irradiation is low, , Furthermore, the adhesive force after UV irradiation was high, and evaluation of adhesive residual and processing liquid penetration property was "x (impossibility)". It is estimated that this is because dipentaerythritol hexaacrylate does not form a crosslinked structure with (a) hydroxyl-containing (meth)acrylic resin.

According to the present invention, by using as a material for forming the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet, the penetration of the treatment liquid into the interface with the adherend can be suppressed, and the pressure-sensitive adhesive remains on the surface of the adherend from which the pressure-sensitive adhesive sheet is peeled off A pressure-sensitive adhesive composition from which a difficult pressure-sensitive adhesive sheet is obtained can be provided.

Claims (9)

(a) a hydroxyl group-containing (meth)acrylic resin,
(b) a modified unsaturated epoxy ester resin containing a hydroxyl group;
(c) a polyisocyanate compound;
(d) a photopolymerization initiator,
The (b) hydroxyl group-containing modified unsaturated epoxy ester resin,
An ethylenically unsaturated group bonded to a secondary carbon atom derived from an epoxy group through an oxy group,
having an α,β-unsaturated monobasic acid group bonded to a primary carbon atom derived from an epoxy group,
The (b) hydroxyl group-containing modified unsaturated epoxy ester resin has or does not have an epoxy group,
the number of α,β-unsaturated monobasic acid groups is greater than or equal to the number of epoxy groups,
The pressure-sensitive adhesive composition, characterized in that the (c) polyisocyanate compound is a polyisocyanate derived from an aliphatic diisocyanate. According to claim 1,
The said (b) hydroxyl-containing modified unsaturated epoxy ester resin has an unsaturated epoxy ester resin structure derived from the reaction product of a bisphenol-type epoxy resin and (meth)acrylic acid, The adhesive composition. 3. The method of claim 1 or 2,
The (b) hydroxyl group-containing modified unsaturated epoxy ester resin is a compound represented by the following formula (1), the pressure-sensitive adhesive composition.

(in formula (1), two R ¹ are independently a hydrogen atom or a methyl group; R ² is a hydrogen atom or a group having an ethylenically unsaturated bond; X is a repeating unit comprising a group derived from an epoxy resin; n is is an integer from 1 to 100; when R ² is a hydrogen atom, [X] _n has at least one group having an ethylenically unsaturated bond; when n is 2 to 100, X may be one type or two or more .) 4. The method of claim 3,
Said X is represented by following formula (2) or following formula (3), The adhesive composition.

(In formula (2), two R ³ are independently a hydrogen atom or a methyl group; R ⁴ is a hydrogen atom or a group having an ethylenically unsaturated bond.)

(In formula (3), two R ⁵ are independently a hydrogen atom or a methyl group; R ⁶ is a hydrogen atom or a group having an ethylenically unsaturated bond.) 5. The method according to any one of claims 1 to 4,
Content of said (c) polyisocyanate compound is 0.5-15 mass parts with respect to a total of 100 mass parts of (a) hydroxyl-containing (meth)acrylic resin and (b) hydroxyl-containing modified unsaturated epoxy ester resin, The adhesive composition. 6. The method according to any one of claims 1 to 5,
The mass ratio of the (a) hydroxyl group-containing (meth)acrylic resin and the (b) hydroxyl group-containing modified unsaturated epoxy ester resin is 60:40 to 40:60, the pressure-sensitive adhesive composition. A pressure-sensitive adhesive layer is provided on one side of the substrate,
The said adhesive layer contains the adhesive composition in any one of Claims 1-6, The adhesive sheet characterized by the above-mentioned. 7. The method according to any one of claims 1 to 6,
The mass ratio of the (a) hydroxyl group-containing (meth)acrylic resin and the (b) hydroxyl group-containing modified unsaturated epoxy ester resin is 60:40 to 40:60,
(c) content of polyisocyanate compound is 0.5-15 mass parts with respect to a total of 100 mass parts of (a) hydroxyl-containing acrylic resin and (b) hydroxyl-containing modified unsaturated epoxy ester resin,
(d) Content of a photoinitiator is 0.1-5 mass parts with respect to a total of 100 mass parts of (a) hydroxyl-containing (meth)acrylic resin and (b) hydroxyl-containing modified unsaturated epoxy ester resin, The adhesive composition. 8. The method of claim 7,
The pressure-sensitive adhesive sheet, wherein the substrate is a transparent sheet-like or film-like substrate.