JPH07216338A - Hardenable pressure-sensitive composition and sheet or tape coated therewith - Google Patents

Abstract

PURPOSE:To obtain a composition which is the so-called hardenable pressure- sensitive adhesive having such a pressure-sensitive adhesiveness as to permit resticking at the time of sticking and capable of being hardened to develop high adhesiveness after sticking. CONSTITUTION:This composition comprises a copolymer comprising phenylmaleimide and an acrylic monomer, a compound having at least two acryloyl or methacryloyl groups in the molecule, a tackifier, a polymerization, initiator, a polyisocyanate, and optionally an active-hydrogen-containing acrylic polymer other than the above copolymer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention has tackiness at the time of joining and can be temporarily adhered to adherends of resins such as metals.
A curable pressure-sensitive adhesive composition suitable as a so-called tacky adhesive, which shows a strong adhesive force when cured by heating, and a pressure-sensitive adhesive sheet made by coating or impregnating the same with a base material. Or regarding tape.

[0002]

2. Description of the Related Art Conventionally, as a curable pressure-sensitive adhesive composition, a non-reactive or reactive pressure-sensitive adhesive polymer to which a reactive oligomer or monomer is added is known (Japanese Patent Publication No. 50-28970). JP-B-53-31898, JP-A-53-118439, JP-B-54-
No. 28877, No. 60-69178, No. 61-18591, and No. 61-83273.
JP, JP-A-61-83274, JP-A-61-
No. 101583, Japanese Patent Publication No. 1-36513, Japanese Patent Publication No. 2-5791, etc.). However, in these compositions, when a large amount of reactive oligomer or monomer is added in order to obtain sufficient adhesive force after curing,
The adhesive property before curing, particularly the cohesive force was lowered, and there was a possibility that slippage or peeling might occur between the time of sticking and the time of curing. on the other hand,
If the amount of the reactive oligomer or monomer added is reduced in order to improve the adhesive property before curing, especially the cohesive force, the curability becomes low, resulting in insufficient adhesive force. As described above, a curable pressure-sensitive adhesive composition having sufficiently excellent adhesive properties before curing, particularly cohesive force and adhesive force after curing, has not been developed. Therefore, the previous invention (Japanese Patent Laid-Open No.
-145186, JP-A-04-145113, JP-A-04-255782), unsaturated polyester oligomers, adhesive acrylic polymers,
We have developed a pressure-sensitive adhesive composition that gives excellent curability by combining a polymerization initiator, a polyisocyanate, and a silane coupling agent. Therefore, when a thin metal plate or a resin plate is used as the adherend, there is a problem that it is difficult to peel and re-attach it again.

[0003]

This curable pressure-sensitive adhesive composition has a reduced initial tack, enables re-adhesion of an adherend, and has the same adhesive strength as conventional adhesives. Aimed to have.

[0004]

The present invention provides a copolymer (A) comprising phenylmaleimide and an acrylic monomer,
2 acryloyl or methacryloyl groups in the molecule
A compound (B) having more than one, a tackifier (C),
The present invention relates to a curable pressure-sensitive adhesive composition containing a polymerization initiator (D), a polyisocyanate (E), and optionally an acrylic polymer (F) containing active hydrogen other than the copolymer (A). Furthermore, the present invention relates to a sheet or tape obtained by applying or impregnating a substrate with the curable pressure-sensitive adhesive composition.

In the curable pressure-sensitive adhesive composition of the present invention, the copolymer (A) composed of phenylmaleimide and an acrylic monomer means phenylmaleimide, hydroxyl group, tertiary amino group, carboxyl group, amide group, N- One or several of acrylic monomers having a substituted amide group, a nitrile group, and the like, and in some cases, alkyl (meth)
It is a copolymer with monomers such as acrylate, vinyl acetate, vinyl ether, and styrene. The content of phenylmaleimide in the copolymer is 5 to 50 mol%, preferably 2
It is 0 to 30 mol%. The weight average molecular weight is 200.
000 to 1,000,000, and the glass transition temperature is in the range of 20 to 50 ° C.

Examples of the monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and N-methylolacrylamide. Examples of the monomer having a tertiary amino group include dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, and dimethylaminopropyl (meth) acrylamide. Examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid and citraconic acid. Examples of the monomer having an amide group and an N-substituted amide group include allylamide, methacrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-methoxymethyl (meth) acrylamide,
Examples include N-ethoxymethyl (meth) acrylamide, N-propoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-tert-butylacrylamide, N-octylacrylamide, diacetone acrylamide. Examples of the monomer having a nitrile group include acrylonitrile, methacrylonitrile, crotononitrile, and fumaronitrile. Further, as the alkyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate,
There are alkyl (meth) acrylates such as butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and octyl (meth) acrylate. In addition, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, etc., alkyl (meth) acrylate in which an alkyl group is substituted with an aromatic ring group, a heterocyclic group, a halogen atom, etc., Monomers commonly used in the synthesis of acrylic polymers can also be used in the synthesis of the polymers of the present invention.

The reaction for synthesizing the copolymer is a normal radical polymerization, and there is no limitation on the reaction method, and solution polymerization,
The polymerization can be carried out by a known polymerization method such as bulk polymerization or emulsion polymerization, but solution polymerization is preferred because the reaction can be easily controlled and the next operation can be directly performed. As the solvent, methyl ethyl ketone, methyl isobutyl ketone, toluene, cellosolve, ethyl acetate, butyl acetate, etc. may be any as long as the resin of the present invention is soluble,
A single solvent or a mixture of a plurality of solvents may be used. The polymerization initiator used in the polymerization reaction is also an organic peroxide such as benzoyl peroxide, acetyl peroxide, methyl ethyl ketone peroxide, lauroyl peroxide, an azo initiator such as azobisisobutyronitrile, etc. Any known material may be used without particular limitation.

In the curable pressure-sensitive adhesive composition of the present invention, the compound (B) having two or more acryloyl groups or methacryloyl groups in the molecule includes diethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate and triethylene. Glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth)
Poly (meth) acrylates of polyhydric alcohols such as acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, polyester-based, polyether-based, polyurethane-based , Epoxy oligomer type, polysulfide type,
Examples thereof include poly (meth) acrylates such as polycaprolactone type and polycarbonate type. In particular, a compound having a hydroxyl group and / or an amino group, a cyclic acid anhydride such as a polyvalent carboxylic acid, and an epoxide having an acryloyl group or a methacryloyl group, which are described in JP-A-61-126128, are reacted. The unsaturated polyester oligomer thus obtained is suitable as the compound (B) having two or more acryloyl groups or methacryloyl groups in the molecule. In addition, hydroxyl group and /
Alternatively, as the compound having an amino group, allyl alcohol, ethylene glycol, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, p-hydroxystyrene, 2-cyclohexen-1-ol, ethanolamine, 1- Amino-2
-Propanol, p-aminophenol, etc. are maleic anhydride, phthalic anhydride, 1,2-cyclohexanedicarboxylic acid anhydride, cis-4-anhydrous as the cyclic acid anhydride.
Cyclohexene-1,2-dicarboxylic acid, itaconic anhydride, glutaric anhydride, citraconic anhydride, succinic anhydride, and the like, and as the epoxide, glycidyl (meth) acrylate, glycidyl cinnamate, allyl glycidyl ether, vinylcyclohexene monoepoxide,
Examples are 1,3-butadiene monoepoxide and the like.

In the curable pressure-sensitive adhesive composition of the present invention, tackifier (C) is a natural resin such as a rosin resin or a terpene resin, which is added for the purpose of improving the adhesiveness to an adherend. The derivatives and synthetic resins such as petroleum resin. Rosin-based resins include gum rosin, tall oil rosin, natural rosin such as wood rosin, hydrogenated rosin, polymerized rosin, modified rosin such as maleated rosin, rosin glycerin ester, hydrogenated rosin glycerin ester, polymerized rosin glycerin ester, rosin pentane. There are rosin esters such as erythritol ester, hydrogenated rosin pentaerythritol ester, and polymerized rosin pentaerythritol ester. Terpene resins include terpene resins such as α-pinene, β-pinene and limonene, and terpene phenolic resins such as α-pinene phenol resin and diterpene phenol resin. Besides, aromatic hydrocarbon-modified terpene resins can also be used. Further, as the synthetic resin, an aliphatic, alicyclic, aromatic or other petroleum resin, coumarone indene resin, styrene resin, xylene resin, rosin-modified phenol resin, or the like can be used.

In the curable pressure-sensitive adhesive composition of the present invention, the acrylic polymer (F) containing active hydrogen other than the copolymer (A) means the above-mentioned hydroxyl group, tertiary amino group, carboxyl group, amide group and the like. Is a copolymer of acrylic monomers having a functional group of, and has a weight average molecular weight of 200,000 to 100.
It refers to one of about 0000. It is generally used as an acrylic resin for adhesives and has a glass transition temperature of -5.
It is in the range of to -10 ° C. Further, even if the polymer alone has poor adhesiveness, a compound (B) having two or more acryloyl groups or methacryloyl groups in the molecule, or a polymer showing good adhesive properties by adding another resin is It can be used as the acrylic polymer (F) having active hydrogen of the present invention.

Each of the obtained copolymers (A) consisting of phenylmaleimide and an acrylic monomer, a compound (B) having two or more acryloyl groups or methacryloyl groups in the molecule, a tackifier (C), and a copolymer. By mixing the acrylic polymer (F) containing active hydrogen other than the polymer (A), a tacky resin having curability can be obtained. It is sufficient to stir the mixture at room temperature until it becomes apparently uniform, but heating and stirring may be performed at a temperature equal to or lower than the boiling point of the solvent in order to further enhance the state of mutual mixing. In the present invention, the compound (B) having two or more acryloyl groups or methacryloyl groups in the molecule has an unsaturated group, and when used in combination with a suitable polymerization initiator (D), it is easily solidified by a thermosetting method. be able to.

As the polymerization initiator (D) used in the present invention, dialkyl peroxides such as di-tert-butyl peroxide, tert-butyl cumyl peroxide, dicumyl peroxide, acetyl peroxide, lauroyl peroxide. , Diacyl peroxides such as benzoyl peroxide, methyl ethyl ketone peroxide, cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, ketone peroxides such as methyl cyclohexanone peroxide, 1,1-bis (tert-butyl) Peroxy) cyclohexane and the like peroxy ketals, tert-butyl hydroperoxide, cumene hydroperoxide, 1, 1, 3,
3-tetramethylbutyl hydroperoxide, p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-
Hydroperoxides such as 2,5-dihydroperoxide, tert-butylperoxyacetate, t
Organic peroxides such as peroxyesters such as ert-butylperoxy-2-ethylhexanoate and tert-butylperoxybenzoate, azo compounds such as azobisisobutyronitrile and azobisvaleronitrile, There is no particular limitation as long as it is a known compound that is usually used as a radical generator.

When an organic peroxide having a low radical generation rate is used, N, N-dimethylbenzylamine, triethylamine, tributylamine, N, N
-Diethylaniline, N, N-dimethylaniline, N-
Tertiary amines such as phenyldiethanolamine, N-phenyldiisopropanolamine, dimethyl-p-toluidine, triethanolamine, 4-phenylmorpholine, lithium, calcium, strontium, barium, cerium, zirconium, vanadium, molybdenum, manganese, iron Laurates, naphthenates, octylates, oleates, octenoates, and other fatty acid salts of metals such as cobalt, nickel, copper, zinc, tin, and lead; resin salts such as rosin salts; acetylacetate One or more metal compounds selected from chelate compounds such as nate complex salts may be used as an accelerator. Of these accelerators, the tertiary amine is usually 1 to 100 parts by weight with respect to 100 parts by weight of the organic peroxide, and the metal compound is 100 parts by weight of the organic peroxide.
It is used in a proportion of 0.01 to 10 parts by weight.

In order to improve the adhesive property before curing, and in particular to increase the cohesive force, polyisocyanate (E) is further added to the curable adhesive composition of the present invention to form phenylmaleimide and an acrylic monomer. The copolymer (A) and the acrylic polymer (F) containing active hydrogen other than the copolymer (A) can be partially crosslinked. Such polyisocyanates include tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, m-xylene diisocyanate, p-xylene diisocyanate, 1,5-naphthalene diisocyanate, isophorone diisocyanate, lysine diisocyanate, hydrogenated 4,
There are diisocyanates such as 4′-diphenylmethane diisocyanate and hydrogenated tolylene diisocyanate, or both ends isocyanate adducts of these with glycols or diamines, or a mixture thereof, and triphenylmethane triisocyanate, poly 3 such as methylene polyphenyl isocyanate
Functional or higher polyisocyanates can also be used as a mixture with diisocyanates.

The addition amount of the compound (B) having two or more acryloyl groups or methacryloyl groups in the molecule is, in terms of solid content, 5 per 100 parts by weight of the copolymer (A) consisting of phenylmaleimide and an acrylic monomer. From 12
It is used in an amount of 0 parts by weight, preferably 5 to 60 parts by weight. Further, in the above composition, 1 of the copolymer (A) is used.
It is permissible to replace 0 to 90% by weight with the acrylic polymer (F). The amount of the tackifier (C) added is 20 to 120 parts by weight, preferably 30 parts by weight in terms of solid content, based on 100 parts by weight of the total amount of the copolymer (A) or the copolymer (A) and the acrylic polymer (F). Used in the range of 60 to 60 parts by weight. The amount of the polymerization initiator (D) added is
2 acryloyl or methacryloyl groups in the molecule
The compound (B) is used in an amount of 1 to 25 parts by weight, preferably 5 to 15 parts by weight, based on 100 parts by weight of the compound (B). The amount of polyisocyanate (E) added is copolymer (A) or copolymer (A) and acrylic polymer (F), compound (B) having two or more acryloyl groups or methacryloyl groups in the molecule, and tacky It is used in the range of 0.1 to 5 parts by weight, preferably 0.2 to 2 parts by weight in terms of solid content, relative to 100 parts by weight in total of the solid content of Fire (C).

The curable pressure-sensitive adhesive composition of the present invention contains pigments, dyes, inorganic fillers, organic solvents, silver powder, copper powder, nickel powder, and other metal powders, if necessary, as long as its performance is not impaired. Carbon black, graphite, silane coupling agent, etc. can be added. The curable pressure-sensitive adhesive composition of the present invention is capable of releasing paper or cloth treated with silicone, paper or cloth processed with a low-adhesive resin such as polyethylene terephthalate film laminated paper, metal foil, plastic film, etc. It is applied onto a high-quality film, sheet, tape or the like, dried to remove the organic solvent if necessary, and cut if necessary to form a double-sided or single-sided adhesive sheet or tape. In addition, for reinforcement and shock absorption, it is lined with non-woven fabric such as rayon and nylon, cloth such as cheesecloth, foam such as urethane and acrylic, and these cloths and foams are used as core materials. The curable pressure-sensitive adhesive composition of the present invention can also be used by coating or impregnating it. When the base material, core material, etc. of the tape or sheet used here remains in the adhesive part even after being used together with the curable pressure-sensitive adhesive composition, these are remarkably deteriorated by the treatment such as heating or the curing is significantly hindered. It has to be something that has nothing to do. The double-sided pressure-sensitive adhesive sheet or tape thus obtained is
The curable pressure-sensitive adhesive composition may be sandwiched between two adherends of the same kind or different kinds, and temporarily adhered due to its adhesiveness, and then the curable pressure-sensitive adhesive composition may be cured by heat treatment to firmly adhere the adherends to each other. it can. In addition, a single-sided adhesive sheet or tape is temporarily adhered to an adherend due to its adhesiveness, and if necessary, the sheet or tape which is the base material is peeled off, and another adherend is attached to the resulting adhesive surface. Further, the curable pressure-sensitive adhesive composition is cured by temporary adhesion and heat treatment, and can be firmly adhered to the adherend. When curing,
When air is heated in an oven, it is usually 3 at 80-150 ° C.
Approximately 20 minutes, 80 to 1 for contact heating such as hot pressing
Heating is performed at 50 ° C. for about 0.5 seconds to 5 minutes.

[0017]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these ranges. In addition,
Parts and% in the examples represent parts by weight and% by weight, respectively. Synthesis of Copolymer (A) Composed of Phenylmaleimide and Acrylic Monomer Copolymer 1 Phenylmaleimide 85.4 parts Butyl acrylate 161.9 parts Butyl methacrylate 2.8 parts Acrylamide 7.0 parts 2-Hydroxyethyl methacrylate 12 .9 parts Azobisisobutylnitrile 0.8 parts Ethyl acetate 330.0 parts

Copolymer 2 Phenylmaleimide 87.5 parts Butyl acrylate 116.6 parts 2-Hydroxyethyl methacrylate 13.2 parts Styrene 52.7 parts Azobisisobutylnitrile 0.8 parts Ethyl acetate 330.0 parts Copolymer 3 Phenylmaleimide 87.6 parts Butyl acrylate 129.7 parts Styrene 52.7 parts Azobisisobutylnitrile 0.8 parts Ethyl acetate 330.0 parts

The above compositions were mixed, heated in a nitrogen atmosphere at 80 ° C. for 16 hours, and cooled to obtain three kinds of copolymer solutions (solid content: 45%). 2 acryloyl or methacryloyl groups in the molecule
Synthesis of compound (B) having 2 or more acryloyl groups or methacryloyl groups in a molecule 1 ethylene glycol 2.0 parts hexahydrophthalic anhydride 51.0 parts glycidyl methacrylate 47.0 parts N, N-dimethylbenzyl Amine 0.9 parts Hydroquinone 0.2 parts Ethyl acetate 33.7 parts Compound 2 having two or more acryloyl groups or methacryloyl groups in the molecule 2 Ethylene glycol 2.5 parts Succinic anhydride 40.3 parts Glycidyl methacrylate 57.2 parts N, N-dimethylbenzylamine 1.1 parts Hydroquinone 0.2 parts Ethyl acetate 33.7 parts

The above composition was mixed and then mixed in an air atmosphere at 80
After reacting at 16 ° C. for 16 hours and cooling, a compound (solid content: 75%) having two or more acryloyl groups or methacryloyl groups in the molecule was obtained. Synthesis of Acrylic Polymer (F) Containing Active Hydrogen Other Than Copolymer (A) Acrylic Polymer Containing Active Hydrogen 1 Butyl Acrylate 92.0 parts Acrylamide 2.8 parts 2-Hydroxyethyl Methacrylate 5.2 parts Azobis Isobutyronitrile 0.2 parts Ethyl acetate 150.0 parts Acrymolymer containing active hydrogen 2 Methyl acrylate 100.0 parts Azobisishibutyronitrile 0.2 parts Ethyl acetate 150.0 parts Heated to 80 ° C. To 125 parts of the mixture having the above composition, 125 parts of the above mixture having the same composition was added dropwise.
The mixture was heated under reflux for a period of time and cooled to obtain a solution of acrylic polymer containing 2 kinds of active hydrogen (solid content: 40%).

Example 1 22.2 parts of a solution of copolymer 1, 8.0 parts of a solution of compound 1 having two or more acryloyl groups or methacryloyl groups in the molecule, pentaline 2 manufactured by Rika Hercules Co., Ltd.
6.4 parts of 590 solution were mixed thoroughly and the resin solution 10
2.5 parts of benzoyl peroxide was uniformly mixed with 0 part of the mixture, 0.5 part of tolylene diisocyanate was further added, and the thickness after drying was 50 μm on a polyethylene-treated polyethylene terephthalate film. And then dried at 90 ° C for 2 minutes to obtain an adhesive sheet,
Further, it was aged at 20 ° C. for 7 days. Table 1 shows the measurement results of the adhesive properties of the obtained pressure-sensitive adhesive sheet before curing (peeling adhesive force, ball tack, probe tack, holding force), and shear adhesive force after curing and peeling adhesive force. Cure 10
It was carried out by heating for 60 seconds in a hot press at 0 ° C. The measurement was performed as follows.

(1) Peeling adhesive strength before curing A polyethylene terephthalate sheet having a thickness of 50 μm was adhered to the adhesive surface of the obtained adhesive sheet, cut into a width of 25 mm, and then the polyethylene terephthalate film was peeled off to form. Adhesive surface is adhered to # 280 sandpaper-polished stainless steel plate (SUS304), left for 30 minutes, and then peeled at 180 degrees at a peeling speed of 300 mm / min under conditions of 25 ° C. and 65% relative humidity. Was measured. (2) Ball tack before curing Set the obtained pressure-sensitive adhesive sheet on the slope with an inclination angle of 30 degrees, and run at a running distance of 10c under the conditions of 25 ° C and relative humidity of 65%.
At m, roll a stainless steel ball, sticky surface 1
The number of the highest ball that stopped within 0 cm was measured. The number of the ball is represented by 32 times as many as 31 kinds of "name of ball" from 1/16 to 1. (3) Probe tack before curing A stainless steel cylinder (probe) with a diameter of 5 mm was used at a contact speed of 10 mm / sec and a contact load of 0.98 N / cm ² .
After contacting the adhesive surface of the obtained adhesive sheet for 1 second, 1
The force required to pull the probe vertically from the adhesive surface at a speed of 0 mm / sec was measured.

(4) Holding power before curing A polyethylene terephthalate sheet having a thickness of 50 μm is adhered to the adhesive surface of the obtained adhesive sheet, cut into a size of 25 mm width and 100 mm length, and then a polyethylene terephthalate film. Of the resulting adhesive surface, and affixed to the stainless steel plate (SUS304) where the 25 mm long and 25 mm wide portions of the resulting adhesive surface were polished with sandpaper # 280,
The time (seconds) until the adhesive sheet dropped from the stainless steel plate was measured at 40 ° C. and a load of 1 kg. (5) Shear adhesive strength after curing 50 mm in length, 10 mm in width, and 0.5 mm in thickness of one side of an aluminum plate, the obtained pressure-sensitive adhesive sheet was 10 mm in length and 1 in width.
Stick the adhesive surface of what was cut to 0 mm, peel off the release paper, and stick an aluminum plate of the same size to the resulting adhesive surface,
After curing the pressure-sensitive adhesive, the shear strength was measured at a pulling rate of 5 mm / min under the conditions of 25 ° C. and relative humidity of 65%. (6) Peeling Adhesion after Curing 100 mm long, 25 mm wide, and 0.1 mm thick aluminum plate was attached to one end of the obtained pressure-sensitive adhesive sheet, the adhesive surface of which was cut to a length of 70 mm and a width of 25 mm. The paper was peeled off, an aluminum plate of the same size was attached to the resulting adhesive surface, the adhesive was cured, and the shear strength was measured at a pulling speed of 300 mm / min under conditions of 25 ° C. and 65% relative humidity.

Example 2 2.22 parts of solution of copolymer 1, 8.0 parts of solution of compound 1 having 2 or more acryloyl groups or methacryloyl groups in the molecule, acrylic polymer 1 containing active hydrogen
22.5 parts of the above solution and 6.4 parts of pentaline 2590 solution manufactured by Rika Hercules Co., Ltd. were thoroughly mixed, and 2.5 parts of benzoyl peroxide was uniformly mixed with 100 parts of this resin solution, and further tri Diisocyanate 0.
5 parts were added and coated on a silicone-treated polyethylene terephthalate film so that the thickness after drying would be 50 μm, dried at 90 ° C. for 2 minutes to obtain a pressure-sensitive adhesive sheet, and further aged at 20 ° C. for 7 days. Let The obtained pressure sensitive adhesive sheet was evaluated in the same manner as in Example 1. Example 3 2.22 parts of solution of copolymer 1, 12.0 parts of solution of compound 2 having two or more acryloyl groups or methacryloyl groups in the molecule, 15.0 parts of solution of acrylic polymer 2 containing active hydrogen , 6.4 parts of pentaline 2590 solution manufactured by Rika Hercules Co., Ltd. was thoroughly mixed, and 100 parts of this resin solution was mixed with 2.5 parts of benzoyl peroxide.
Parts are evenly mixed, 0.2 part of hexamethylene diisocyanate is further added, and the thickness after drying is 50 on a polyethylene terephthalate film treated with silicone.
The adhesive sheet was applied so as to have a thickness of μm, dried at 90 ° C. for 2 minutes to obtain an adhesive sheet, and further aged at 20 ° C. for 7 days. The obtained pressure sensitive adhesive sheet was evaluated in the same manner as in Example 1.

Example 4 11.1 parts of solution of copolymer 2, 8.0 parts of solution of compound 1 having two or more acryloyl groups or methacryloyl groups in the molecule, acrylic polymer 1 containing active hydrogen
Solution (12.5 parts) and Rika Hercules Co., Ltd. pentaline 2590 solution (6.4 parts) were thoroughly mixed, and 100 parts of this resin solution was uniformly mixed with 2.5 parts of benzoyl peroxide. Diisocyanate 0.
5 parts were added and coated on a silicone-treated polyethylene terephthalate film so that the thickness after drying would be 50 μm, dried at 90 ° C. for 2 minutes to obtain a pressure-sensitive adhesive sheet, and further aged at 20 ° C. for 7 days. Let The obtained pressure sensitive adhesive sheet was evaluated in the same manner as in Example 1. Example 5 11.1 parts of solution of copolymer 3, 8.0 parts of solution of compound 1 having two or more acryloyl groups or methacryloyl groups in the molecule, acrylic polymer 1 containing active hydrogen
Solution (12.5 parts) and Rika Hercules Co., Ltd. pentaline 2590 solution (6.4 parts) were thoroughly mixed, and 100 parts of this resin solution was uniformly mixed with 2.5 parts of benzoyl peroxide. Diisocyanate 0.
5 parts were added and coated on a silicone-treated polyethylene terephthalate film so that the thickness after drying would be 50 μm, dried at 90 ° C. for 2 minutes to obtain a pressure-sensitive adhesive sheet, and further aged at 20 ° C. for 7 days. Let The obtained pressure sensitive adhesive sheet was evaluated in the same manner as in Example 1.

Comparative Example 1 Solution 25.0 of acrylic polymer 1 containing active hydrogen
Parts, 8.0 parts of a solution of compound 1 having two or more acryloyl groups or methacryloyl groups in the molecule, and 6.4 parts of pentaline 2590 solution manufactured by Rika Hercules Co., Ltd. are thoroughly mixed to 100 parts of this resin solution. Then, 2.5 parts of benzoyl peroxide is uniformly mixed, 0.5 part of tolylene diisocyanate is further added, and the resulting product is applied on a polyethylene-treated polyethylene terephthalate film so that the thickness after drying is 50 μm. The adhesive sheet was dried at 90 ° C. for 2 minutes, and further aged at 20 ° C. for 7 days. The obtained pressure sensitive adhesive sheet was evaluated in the same manner as in Example 1. The evaluation results of each example are shown in Table 1. As is clear from Table 1, the curable pressure-sensitive adhesive compositions of the respective examples had lower peel adhesion, ball tack, and probe tack before curing than those of the comparative examples, so that they were adhered to an adherend. It shows that the repair is easy. Further, in the curable pressure-sensitive adhesive composition of Example 1, the peel adhesive strength before and after curing was significantly reduced, but the shear adhesive strength after curing showed a high value. On the other hand, in the curable pressure-sensitive adhesive compositions of Examples 2 to 5, the peel adhesive strength after curing is lower than that of the conventional curable pressure-sensitive adhesive compositions, but the shear adhesive strength shows almost the same value. It was

Table 1 ─────────────────────────────────── Before hardening After hardening ──── ────────────── ─────────── Peeling ball Probe holding force Shearing Peeling adhesive force Tack tack Adhesive force Adhesive force (g / 25mm) ) (Time) (Kg / cm ² ) (g / 25mm) ──────────────────────────────────── Example 1 40 <5 0.01>1> 60.0 220 2 1770 <5 0.14> 1 22.9 1630 3 2120 <5 0.18> 1 20.5 1890 4 900 <5 0.06> 1 25.5 1100 5 1410 <5 0.10> 1 25.2 1020 Comparative Example 1 3250 11 0.66> 1 27.7 2540 ─────────────────── ──── ────────────

[0028]

As described above, according to the present invention, by changing the compounding amount of the copolymer of phenylmaleimide and the acrylic monomer and the acrylic polymer containing active hydrogen other than the copolymer, it is possible to reduce the amount before curing. It has become possible to obtain a curable pressure-sensitive adhesive composition which has tack and has an adhesive strength which is almost comparable to that of a conventional pressure-sensitive adhesive after curing. Further, the sheet and tape using the same can be peeled off and reattached before curing even when a thin metal plate or resin plate is used as an adherend.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location C09J 193/04 JAK (72) Inventor Makoto Doi 2-3-13 Kyobashi, Chuo-ku, Tokyo Toyo I Nki Manufacturing Co., Ltd.

Claims (3)

[Claims] 1. A copolymer (A) comprising phenylmaleimide and an acrylic monomer, a compound (B) having two or more acryloyl groups or methacryloyl groups in the molecule, a tackifier (C), a polymerization initiator (D). ,
And a polyisocyanate (E), which is a curable pressure-sensitive adhesive composition. 2. An acrylic polymer (F) containing active hydrogen other than the copolymer (A) consisting of phenylmaleimide and an acrylic monomer is further compounded.
Curable adhesive composition of description. 3. A pressure-sensitive adhesive sheet or tape obtained by coating or impregnating a substrate with the curable pressure-sensitive adhesive composition according to claim 1.