JPH10183092A - Adhesive composition and processed adhesive product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive composition which is excellent in adhesion to a foam base material having a high expansion ratio and excellent in heat resistance, and a pressure-sensitive adhesive product using the same. SOLUTION: The pressure-sensitive adhesive composition of the present invention has 59.5 to 99.99% by weight of a (meth) acrylic acid alkyl ester monomer (A-1) having an alkyl group having 2 to 18 carbon atoms, in a molecule. A vinyl monomer (A-2) containing a hydroxyl group and capable of being radically copolymerized with the above (A-1) 0.0
1 to 0.5% by weight, 1 to 10% by weight of the polymerizable polymer (A-3) represented by the general formula (1), and (A-1)
Vinyl monomers (A-4) 0 to 3 copolymerizable with
100 parts by weight of an acrylic copolymer (A) obtained by radical copolymerization of 0% by weight with a softening point of 120 to
It is composed of 2 to 30 parts by weight of a tackifier resin (B) at 145 ° C, and 0.01 to 5 parts by weight of an isocyanate-based crosslinking agent (C).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acrylic pressure-sensitive adhesive composition excellent in adhesion to a foam substrate and heat resistance, and a pressure-sensitive adhesive product using the same.

[0002]

2. Description of the Related Art Adhesive processed products such as adhesive tapes and adhesive sheets are widely used for applications such as building materials, home electric appliances, automobile cushioning materials, and gap tapes. As a pressure-sensitive adhesive product, a pressure-sensitive adhesive composition is laminated on the surface of the substrate, a double-sided pressure-sensitive adhesive tape,
An adhesive tape or the like using a foam as a base material is generally used.

[0003] Such pressure-sensitive adhesive compositions for processed pressure-sensitive adhesive products include solvent-type pressure-sensitive adhesive compositions mainly composed of acrylic resins in that they are excellent in weather resistance, durability, heat resistance, cold resistance, water resistance and the like. Many things are used. In recent years, as the applications of such pressure-sensitive adhesive processed products have been expanded, more advanced properties have been required for the acrylic pressure-sensitive adhesive composition used.

[0004] Foam pressure-sensitive adhesive tapes based on various rubber-based foams are generally used because it is difficult to directly apply a pressure-sensitive adhesive composition solution to a foam substrate because the substrate is porous. Is produced by a method in which a pressure-sensitive adhesive composition solution is once applied to release paper or the like, dried, and then pressure-transferred onto a foam base material.

JP-A-3-281587 discloses an acrylic pressure-sensitive adhesive composition containing an acrylic polymer and a tackifying resin as main components, wherein the tackifying resin is obtained by reacting a resin acid and a polyhydric alcohol. Resin acid ester having a hydroxyl value of 50 to 1
Although it is disclosed that the acrylic pressure-sensitive adhesive composition of No. 00 is excellent in various properties, this acrylic pressure-sensitive adhesive composition was used for a foam base material having a high expansion ratio such as a urethane foam base material. In this case, the adhesion area by transfer is insufficient,
Adhesion to the foam substrate is reduced.

As a method for solving such a problem,
Conventionally, a monomer having a low glass transition temperature is copolymerized in an acrylic pressure-sensitive adhesive composition at a higher ratio than usual, or by adding a liquid component or a tackifying resin having a low softening point, to form a dry film of the pressure-sensitive adhesive composition. An elastic modulus near normal temperature is set to be low.

However, these methods have disadvantages such as a decrease in the elastic modulus near high temperatures and a decrease in heat resistance. As a method of solving this, there are a method of simply further copolymerizing a monomer having a high glass transition temperature, a method of further adding a tackifier resin having a high softening point, and the like. However, there is a problem that the adhesion to the foam base material is reduced. As described above, there has been no acrylic pressure-sensitive adhesive composition for a foam pressure-sensitive adhesive tape using a foam base material having a high expansion ratio with satisfactory performance.

[0008]

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides an acrylic pressure-sensitive adhesive composition having excellent adhesion to a foam substrate having a high expansion ratio and excellent heat resistance. An object of the present invention is to provide a pressure-sensitive adhesive processed product using the same.

[0009]

The pressure-sensitive adhesive composition according to claim 1 (hereinafter referred to as "the present invention 1") comprises a (meth) acrylic acid alkyl ester monomer having an alkyl group having 2 to 18 carbon atoms. A-1) 59.5 to 98.9% by weight,
A vinyl-based monomer (A-2) containing a hydroxyl group in the molecule and capable of being radically copolymerized with the alkyl (meth) acrylate monomer (A-1) 0.01 to 0.5% by weight; (1);

[0010]

Embedded image

Wherein R ¹ represents hydrogen or a methyl group.
R ² represents a non-polymerizable polymer having a weight average molecular weight of 2,000 to 50,000 and a glass transition temperature of 50 to 200 ° C. 1) to 10% by weight of the polymerizable polymer (A-3) represented by the formula (1) and a vinyl monomer (A-4) 0 copolymerizable with the alkyl (meth) acrylate monomer (A-1). 100 parts by weight of an acrylic copolymer (A) obtained by radical copolymerization of 30 to 30% by weight, 2 to 30 parts by weight of a tackifier resin (B) having a softening point of 120 to 145 ° C, and isocyanate It is characterized by comprising 0.01 to 5 parts by weight of the system crosslinking agent (C).

The pressure-sensitive adhesive composition according to claim 2 (hereinafter referred to as “the present invention 2”) is the pressure-sensitive adhesive composition of the present invention 1 and has an insoluble fraction (gel fraction) in ethyl acetate of 20 to 20.
It is characterized by being 50% by weight.

The pressure-sensitive adhesive composition according to the third aspect (hereinafter referred to as "the present invention 3") comprises the above acrylic copolymer (A) 1
00 parts by weight, 2 to 30 parts by weight of a rosin ester-based tackifying resin (B-1) having a softening point of 120 to 160 ° C, 0.1 to 5 parts by weight of a liquid tackifying resin (B-2), and
The isocyanate-based cross-linking agent (C) comprises 0.01 to 5 parts by weight.

The pressure-sensitive adhesive composition according to claim 4 (hereinafter referred to as “the present invention 4”) is the pressure-sensitive adhesive composition of the present invention 3, and has an insoluble fraction (gel fraction) in ethyl acetate of 20 to 20.
It is characterized by being 50% by weight.

[0015] The pressure-sensitive adhesive product according to claim 5 (hereinafter referred to as "the present invention 5") is characterized in that at least one of the pressure-sensitive adhesive compositions according to claims 1 to 4 is laminated on another article. It is assumed that.

Hereinafter, the present invention will be described in detail. The acrylic copolymer (A) used in the pressure-sensitive adhesive composition of the present invention has an alkyl group (meth) acrylic acid alkyl ester monomer (A-1) having 5 to 98. 9
9% by weight of a vinyl monomer (A-2) having a hydroxyl group in the molecule and being radically copolymerizable with the alkyl (meth) acrylate monomer (A-1) 0.01
To 0.5% by weight, 1 to 10% by weight of the polymerizable polymer (A-3) represented by the general formula (1), and the (meth)
It is obtained by radically copolymerizing 0 to 30% by weight of a vinyl monomer (A-4) copolymerizable with the acrylic acid alkyl ester monomer (A-1).

The alkyl (meth) acrylate monomer (A-1) is not particularly limited.
Ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, etc. Can be Preferably, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, or the like is used.

The vinyl monomer (A-2) is not particularly restricted but includes, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate. And the like.

The polymerizable polymer (A-3) is a so-called macromonomer having a polymerizable (meth)
It has an acrylate group and has a non-polymerizable polymer segment R ² at the other end.

The weight-average molecular weight of the non-polymerizable polymer segment represented by R ² is from 2,000 to 50,000, and the glass transition temperature is from 50 to 200 ° C. If the weight average molecular weight is too small, the elastic modulus at high temperature of the pressure-sensitive adhesive composition will be too small, and heat resistance and creep resistance will be reduced.
Further, if the weight average molecular weight is too large, the reactivity of the polymerizable polymer decreases, so that the content is limited to the above range. Preferably it is 3000-20,000. When the glass transition temperature is less than 50 ° C., the elastic modulus at a high temperature of the pressure-sensitive adhesive composition is too small, and the heat resistance and the creep resistance are reduced. On the other hand, when the temperature exceeds 200 ° C., the elastic modulus of the pressure-sensitive adhesive composition near normal temperature is large, and the adhesiveness to the foam base material is reduced.

Examples of R ² include polymethyl methacrylate, polystyrene, and styrene-acrylonitrile copolymer. Of these, polymethyl methacrylate is preferably used. As a method for producing the polymerizable polymer (A-3), for example, US Pat.
No. 786,116, U.S. Pat. No. 3,842,059, and Japanese Patent Application Laid-Open No. 60-133007. The above polymerizable polymer (A-3)
Is not particularly limited, for example, manufactured by Toa Gosei Chemical Industry Co., Ltd., macromonomer AA-6, macromonomer AS-
6, macromonomer AN-6 and the like.

The vinyl monomer (A-4) is not particularly restricted but includes, for example, methyl (meth) acrylate,
Benzyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, (meth) acrylamide, (meth) acrylonitrile, N-
Examples include vinylpyrrolidone, vinyl acetate, styrene, (meth) acrylic acid, maleic anhydride, itaconic acid, crotonic acid and the like.

In the present invention, the acrylic copolymer (A) contains 59.5 to 99.99% by weight of a (meth) acrylic acid alkyl ester monomer (A-1) and a vinyl monomer (A-2) of 0. 9% by weight. 01 to 0.5% by weight, 1 to 10% by weight of the polymerizable polymer (A-3), and a vinyl monomer (A
-4) It is obtained by radical copolymerization of 0 to 30% by weight.

When the amount of the (meth) acrylic acid alkyl ester monomer (A-1) is less than 59.5% by weight, the tack decreases, and when the amount exceeds 99.99% by weight, the cohesive strength decreases and heat resistance and heat resistance are reduced. Since the creep property is deteriorated, it is limited to the above range. 0.01 or less of the vinyl monomer (A-2)
If the amount is less than 0.5% by weight, crosslinking becomes insufficient, and heat resistance and creep resistance are reduced. If the amount exceeds 0.5% by weight, crosslinking is excessive, and tack and adhesive strength are reduced.

When the amount of the polymerizable polymer (A-3) is less than 1% by weight, the elasticity near a high temperature is greatly reduced, so that the heat resistance is lowered. When it exceeds 10% by weight, the elasticity around a normal temperature is also reduced. Since it becomes too high and the adhesion to the foam base material decreases, the content is limited to the above range. Vinyl monomer (A-
When 4) exceeds 30% by weight, the pressure-sensitive adhesive composition becomes hard,
Since the tack and the adhesive strength are reduced, it is limited to the above range.

The method of the radical copolymerization is not particularly limited, but the compounding and coating of the pressure-sensitive adhesive composition are usually carried out in a solution state, so that solution polymerization is preferably used. The solvent used in the solution polymerization is not particularly limited, for example,
Aromatic solvents such as benzene, toluene and xylene; ketone solvents such as acetone and methyl ethyl ketone; acetate solvents such as methyl acetate, ethyl acetate and butyl acetate;
Aliphatic solvents such as n-hexane and n-heptane; alicyclic solvents such as cyclohexane and the like are used.

As the polymerization initiator used in the above solution polymerization, for example, a peroxide-based compound, an azo-based compound and the like can be mentioned, but the polymerization may be carried out by irradiating light or radiation. In the solution polymerization, an appropriate chain transfer agent may be used to adjust the molecular weight. Examples of the chain transfer agent include dodecyl mercaptan.
In this case, the acrylic copolymer (A) preferably has a weight average molecular weight of 300 to 2,000,000. 30
If it is less than this, the cohesive strength becomes insufficient, and the heat resistance and the creep resistance decrease. On the other hand, if it exceeds 2,000,000, the viscosity of the pressure-sensitive adhesive solution becomes too high, so that the coatability is reduced.

The tackifying resin (B) has a softening point of 120 to 1
45 ° C. If the temperature is lower than 120 ° C., the elastic modulus of the pressure-sensitive adhesive composition near high temperature is low and the heat resistance is poor. If it exceeds 145 ° C., the elasticity of the pressure-sensitive adhesive composition near normal temperature increases and the adhesiveness to the foam base material Is reduced, so that it is limited to the above range.
Preferably it is 125-140 degreeC.

The tackifier resin (B) is not particularly restricted but includes, for example, rosin resins, terpene phenol resins, petroleum resins and the like. Is used. These resins may be used alone or in combination of two or more. When two or more types are used in combination, the average softening point (calculation formula: Σ (softening point × number of copies) / Σnumber of copies) may be within the above range.

As the tackifying resin (B), for example, Superester A100 (manufactured by Arakawa Chemical Industries, softening point 1)
00 ° C), Superester A115 (Arakawa Chemical Industries, softening point 115 ° C), Superester A125 (Arakawa Chemical Industries, softening point 125 ° C), Pencel D125
(Arakawa Chemical Industries, softening point 125 ° C), Pencel D1
35 (manufactured by Arakawa Chemical Industry Co., Ltd., softening point: 135 ° C.) and Pencel D160 (manufactured by Arakawa Chemical Industry Co., Ltd., softening point: 160 ° C.) are appropriately selected and mixed to adjust the softening point to the above range. .

The addition amount of the tackifier resin (B) is 2 to 30 parts by weight based on 100 parts by weight of the acrylic copolymer (A). If the amount is less than 2 parts by weight, the adhesion to olefins will be poor and the adaptability to various adherends will be reduced. Also,
If the amount exceeds 30 parts by weight, the heat resistance decreases, so that the amount is limited to the above range. Preferably it is 5 to 20 parts by weight.

The isocyanate-based crosslinking agent (C) is not particularly limited as long as it has two or more isocyanate groups in the molecule. Examples thereof include polyols such as trimethylolpropane and pentaerythritol, and triethylene diisocyanate and diphenylmethane. Isocyanate prepolymers obtained by reacting a polyisocyanate such as diisocyanate and hexamethylene diisocyanate under the condition of an excess of isocyanate groups are exemplified.

As the isocyanate-based crosslinking agent (C),
For example, Sumitomo Bayer Urethane Co., Ltd., Coronate L, isocyanate 0817, Sumidur N-3500, Desmodur Z-4370, etc. are mentioned.

The amount of the isocyanate-based crosslinking agent (C) to be added is 0.01 to 5 parts by weight based on 100 parts by weight of the acrylic copolymer (A). If the amount is less than 0.01 part by weight, crosslinking is insufficient and heat resistance is reduced. If the amount is more than 5 parts by weight, crosslinking proceeds too much and the gel fraction exceeds 50% by weight, so that the polyethylene adheres to the foam base material. The properties are limited, and tack and adhesive strength are reduced. Preferably it is 0.01 to 3 parts by weight.

The pressure-sensitive adhesive composition of the present invention may contain, if necessary, a softener, a plasticizer, a thickener, a thixotropic agent, a bulking agent, a filler, a pigment, a stabilizer within a range not to impair the effects of the present invention. , An antioxidant, an ultraviolet absorber, a rust inhibitor and the like.

Rosin ester-based tackifying resin (B-1)
Has a softening point of 120 to 160 ° C. If the temperature is lower than 120 ° C., the elasticity of the pressure-sensitive adhesive composition at high temperatures is low and the heat resistance is poor. If the temperature exceeds 160 ° C., the elasticity of the pressure-sensitive adhesive composition near normal temperature increases and the adhesiveness to the foam base material increases Is reduced, so that it is limited to the above range. Preferably 125 to 150
° C.

The rosin ester-based tackifying resin (B-
Examples of 1) are not particularly limited, and include, for example, esters of resin acids such as abietic acid or derivatives thereof such as dimers, disproportionates, and hydrogenated products with glycerin, pentaerythritol and the like. These resins may be used alone or in combination of two or more. When two or more types are used in combination, the average softening point (calculation formula: Σ (softening point x number of copies) /
(Number of copies) may be within the above range.

Rosin ester-based tackifying resin (B-1)
Examples thereof include superester A100 (manufactured by Arakawa Chemical Industries, softening point 100 ° C.), superester A1
15 (manufactured by Arakawa Chemical Industries, softening point 115 ° C), Super Ester A125 (manufactured by Arakawa Chemical Industries, softening point 125)
° C), Pencel D125 (manufactured by Arakawa Chemical Industries, softening point 1)
25 ° C), Pencel D135 (manufactured by Arakawa Chemical Industries, softening point 135 ° C), Pencel D160 (manufactured by Arakawa Chemical Industries, Ltd.)
Softening point is adjusted to the above range by appropriately selecting and mixing.

Rosin ester-based tackifying resin (B-1)
Is preferably 2 to 30 parts by weight based on 100 parts by weight of the acrylic copolymer (A). If the amount is less than 2 parts by weight, the adhesion to olefins will be poor and the adaptability to various adherends will be reduced. If it exceeds 30 parts by weight, heat resistance will be reduced. More preferably, it is 5 to 20 parts by weight.

The liquid tackifying resin (B-2) is not particularly limited as long as it is liquid at normal temperature and normal pressure, and examples thereof include rosin ester resins, terpene phenol resins, and xylene-formaldehyde resins. And
Among them, a rosin ester-based resin is preferably used.
Examples of the liquid tackifying resin (B-2) include Superester L (manufactured by Arakawa Chemical Industries, Ltd.) and Stavelite Ester 3 (manufactured by Hercules).

The addition amount of the liquid tackifying resin (B-2) is 0.1 to 100 parts by weight of the acrylic copolymer (A).
1 to 5 parts by weight. If the amount is less than 0.1 part by weight, the adhesion to the foam base material is insufficient, and if the amount is more than 5 parts by weight, the heat resistance is reduced, so that it is limited to the above range. Preferably it is 0.5 to 3 parts by weight.

The pressure-sensitive adhesive composition of the present invention may contain, if necessary, a softener, a plasticizer, a thickener, a thixotropic agent, a bulking agent, a filler, a pigment, a stabilizer as long as the effects of the present invention are not impaired. , An antioxidant, an ultraviolet absorber, a rust inhibitor and the like.

The pressure-sensitive adhesive composition of the present invention is obtained by adding an acrylic copolymer (A) having a structure in which a non-polymerizable polymer segment having a glass transition temperature of 50 to 200 ° C. is graft-polymerized,
In the present invention 1, the tackifier resin (B) having a softening point of 120 to 145 ° C is used. In the present invention 3, the softening point is 120 to 160 ° C.
Since the rosin ester-based tackifying resin and the liquid tackifying resin are mixed in appropriate amounts, the elastic modulus near high temperature can be increased while the elastic modulus near normal temperature is set low.

Accordingly, heat resistance and creep resistance can be improved without lowering the adhesion to a porous substrate such as a urethane foam having a high expansion ratio. Further, since it is appropriately cross-linked with the isocyanate-based cross-linking agent (C), it has excellent heat resistance and creep resistance.

In the present invention 2, the pressure-sensitive adhesive composition of the present invention 1 has an insoluble fraction (gel fraction) in ethyl acetate, and in the present invention 4, the pressure-sensitive adhesive composition of the present invention 3 has an insoluble fraction in ethyl acetate. The fractions (gel fractions) are each limited to 20 to 50% by weight.

The gel as used herein means an insoluble content of the adhesive in ethyl acetate. The adhesive composition solution is applied to the release surface of release paper so that the thickness after drying is 65 μm,
After drying in a dryer at 5 ° C. for 5 minutes, the release surface of the release paper was adhered to the pressure-sensitive adhesive coated surface at 20 ° C., 60% R
Cured under H condition for 1 week. The weight of the thus obtained adhesive and W _1. This was immersed in ethyl acetate and shaken for 3 days, then filtered through a 180 mesh stainless steel net, and the insoluble matter remaining in the net was dried in a dryer at 80 ° C. for 3 hours to completely volatilize the ethyl acetate. The weight of things W ₂
And The gel fraction is a value obtained by the following equation. Gel fraction (% by weight) = (W ₂ / W ₁ ) × 100

If the gel fraction is less than 20% by weight, crosslinking is insufficient and heat resistance is reduced. If it is more than 50% by weight, crosslinking proceeds too much and adhesion to foamed polyethylene is reduced,
Tack and adhesive strength decrease. Preferably it is 25 to 45% by weight. Therefore, the pressure-sensitive adhesive compositions of the present invention 2 and the present invention 4 ensure heat resistance, adhesiveness to foamed polyethylene and adhesive strength.

The above-mentioned pressure-sensitive adhesive compositions of the present invention 1 to 4 are suitably used for pressure-sensitive adhesive products based on rubber-based foams or plastic foams.

The pressure-sensitive adhesive product according to the fifth aspect (hereinafter referred to as "the present invention 5") is obtained by laminating at least one of the pressure-sensitive adhesive compositions of the present invention 1 to 4 on another article. The other article refers to a substrate or release paper as a support usually used for an adhesive tape or sheet.

The above-mentioned pressure-sensitive adhesive processed product may be a single-sided pressure-sensitive adhesive tape, a double-sided pressure-sensitive adhesive tape, a pressure-sensitive adhesive sheet or the like in which the above-mentioned pressure-sensitive adhesive composition is coated on one or both sides of a base sheet. Without using a base sheet, for example, a film-shaped or sheet-shaped pressure-sensitive adhesive composition itself in which at least one of the pressure-sensitive adhesive compositions of the present invention is coated on release paper may be used. It may be laminated on another article.

The type of the substrate is not particularly limited.
For example, various films such as cellophane, polyethylene, polypropylene, polyester, and polystyrene; various nonwoven fabrics such as rayon and cellulose; various plastic foams such as polyethylene foam, polypropylene foam, and polyurethane foam; natural rubber foam, styrene -Various rubber foams such as butadiene rubber foam, chloroprene rubber foam, and acrylonitrile-butadiene rubber foam.

When a pressure-sensitive adhesive product is produced using the above-mentioned substrate, a substrate on which the pressure-sensitive adhesive composition of the present invention is to be applied in order to further enhance the adhesion of the pressure-sensitive adhesive composition of the present invention to the substrate. The material surface (coated surface) may be subjected to a surface treatment such as corona discharge treatment or primer coating in advance, and a substrate surface not coated with the pressure-sensitive adhesive composition of the present invention (hereinafter referred to as “non-coated surface”) ) May be preliminarily subjected to a release treatment on the non-coated surface of the substrate.

The method for applying the pressure-sensitive adhesive composition of the present invention to a substrate may be a conventional method, for example, using a roll coater, a bar coater, a flow coater, a spray coater, a doctor blade or the like. it can.

The coating thickness of the pressure-sensitive adhesive composition of the present invention may be appropriately selected according to the performance and use of the obtained pressure-sensitive adhesive product, and is generally 10 to 200 μm in terms of the film thickness after drying.
The degree is preferred.

When the above-mentioned pressure-sensitive adhesive product is a substrate having the pressure-sensitive adhesive composition of the present invention applied to both sides of a substrate, the pressure-sensitive adhesive composition of the present invention applied to each surface has the same composition. May be present or different.

The pressure-sensitive adhesive product may be one in which a single type of pressure-sensitive adhesive composition is coated in a single layer or a plurality of layers, regardless of whether a substrate is used or a substrate is not used.
A plurality of types of pressure-sensitive adhesive compositions may be applied in a plurality of layers.

Since the pressure-sensitive adhesive product of the present invention 5 is coated with the pressure-sensitive adhesive composition of the present invention, it has excellent heat resistance and creep resistance while having excellent adhesion to the foam base material. Suitable for a wide range of purposes and applications.

[0058]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

(Examples 1 to 9 and Comparative Examples 1 to 8) (1) Polymerization of acrylic copolymer 4 equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer
In a flask, 81.8 parts of monomers, a polymerizable polymer, and ethyl acetate having the compositions shown in Tables 1 and 2 were charged, heated to reflux for 30 minutes, and then 0.1 part of benzoyl peroxide was added. The mixture was dropped and reacted for 7 hours. Then
0.1 part of benzoyl peroxide was further added dropwise and reacted for 3 hours. Thereafter, 40.4 parts of toluene was added and the mixture was cooled to obtain an acrylic copolymer solution having a solid content of 45%.

(2) Preparation of pressure-sensitive adhesive composition A tackifying resin and a liquid tackifying resin having the compositions shown in Tables 1 and 2 were added to the obtained acrylic copolymer solution and mixed. After dilution to 40%, the crosslinking agents shown in Tables 1 and 2 were added and mixed to obtain a pressure-sensitive adhesive composition solution.

(3) Preparation of foam pressure-sensitive adhesive tape The above pressure-sensitive adhesive composition solution was applied to the release surface of release paper using a doctor blade so that the film thickness after drying was 65 μm, and dried at 80 ° C. Dry in machine for 5 minutes. Then, a dry film of the above-mentioned pressure-sensitive adhesive composition was adhered to a urethane foam base material having a thickness of 10 mm and a polyethylene foam base material having a thickness of 5 mm, respectively, and pressed with a pressure roller.
Cured at 0 ° C. and 65% RH for one week to obtain a foam adhesive tape.

(4) Evaluation (80 ° C. Peeling Holding Power) A 25 mm wide foam adhesive tape was stuck on a SUS plate,
After a 2 kg roller is pressed and pressed once, the temperature is 20 ° C.
Cured at 65% RH for 1 day. Then, after leaving it for 30 minutes in an oven at 80 ° C., it was left for 1 hour with a static load of 50 g with the foam adhesive tape face down in the same open. One hour later, the presence or absence of a drop due to peeling was confirmed, and if not, the peel length was measured. The results are shown in Tables 1 and 2.

[0063]

[Table 1]

[0064]

[Table 2]

[Note] Units other than physical properties are parts by weight. * 1: Toa Gosei Chemical Industry Co., Ltd. (trade name "Macromonomer AA-6") * 2: Arakawa Chemical Co., Ltd. (softening point 100 ° C, trade name "Super Ester A100") * 3: Arakawa Chemical Co., Ltd. (Softening point 125 ° C, trade name “Super Ester A125”) * 4: Arakawa Chemical Co., Ltd. (softening point 125 ° C, trade name “Pencel D125”) * 5: Arakawa Chemical Co., Ltd. (softening point 135 ° C, product) * 6: Arakawa Chemical Co., Ltd. (softening point 160 ° C, trade name “Pencel D160”) * 7: Mitsui Petrochemical Co., Ltd. (melting point 125 ° C, trade name “FTR6125”) * 8: Hercules (trade name "Stevelite Ester 3") * 9: Sumitomo Bayer Urethane Co., Ltd., having three isocyanate groups (trade name "Coronate L55") *: Peeling off at the foam interface did.

[0066]

As described above, the pressure-sensitive adhesive composition of the present invention has excellent adhesion to a porous substrate having a high expansion ratio such as urethane foam, and has excellent heat resistance and creep resistance. The pressure-sensitive adhesive product on which the pressure-sensitive adhesive composition is laminated has excellent properties, and is suitably used for a wide range of purposes and applications.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI // C08F290 / 02 C08F290 / 02 C08L75 / 04 C08L75 / 04 (C09J175 / 04 193: 04 201: 00) (C08F 290/02 220: 18 220: 26) (72) Inventor Shigeichi Fukaya 2-1 Hyakuyama, Shimamotocho, Mishima-gun, Osaka Sekisui Chemical Co., Ltd.

Claims (5)

[Claims] 1. An alkyl (meth) acrylate monomer having 2 to 18 carbon atoms in an alkyl group (A-
1) 59.5 to 99.99% by weight of a vinyl monomer (A-2) containing a hydroxyl group in the molecule and capable of undergoing radical copolymerization with the (meth) acrylic acid alkyl ester monomer (A-1) 0.1 to 0.5% by weight, the following general formula (1): (In the formula, R ¹ represents hydrogen or a methyl group. R ² has a weight average molecular weight of 2000 to 50,000 and a glass transition temperature of 5
Represents a non-polymerizable polymer having a temperature of 0 to 200 ° C. 1) to 10% by weight of the polymerizable polymer (A-3) represented by
The alkyl (meth) acrylate monomer (A)
Vinyl monomer (A-4) copolymerizable with -1)
100 parts by weight of an acrylic copolymer (A) obtained by radical copolymerization of 0 to 30% by weight, having a softening point of 1
2 to 30 parts by weight of a tackifying resin (B) having a temperature of 20 to 145 ° C, and 0.01 to 100 parts by weight of an isocyanate-based crosslinking agent (C)
An adhesive composition comprising 5 parts by weight. 2. The pressure-sensitive adhesive composition according to claim 1, wherein the insoluble content (gel content) with respect to ethyl acetate is 20 to 50% by weight. 3. An alkyl (meth) acrylate monomer having an alkyl group having 2 to 18 carbon atoms (A-
1) 59.5 to 99.99% by weight of a vinyl monomer (A-2) containing a hydroxyl group in the molecule and capable of undergoing radical copolymerization with the (meth) acrylic acid alkyl ester monomer (A-1) 0.1 to 0.5% by weight, the following general formula (1): (In the formula, R ¹ represents hydrogen or a methyl group. R ² has a weight average molecular weight of 2000 to 50,000 and a glass transition temperature of 5
Represents a non-polymerizable polymer having a temperature of 0 to 200 ° C. 1) to 10% by weight of the polymerizable polymer (A-3) represented by
The alkyl (meth) acrylate monomer (A)
Vinyl monomer (A-4) copolymerizable with -1)
100 parts by weight of an acrylic copolymer (A) obtained by radical copolymerization of 0 to 30% by weight, having a softening point of 1
2 to 30 parts by weight of a rosin ester-based tackifying resin (B-1) having a temperature of 20 to 160 ° C, and a liquid tackifying resin (B-
2) An adhesive composition comprising 0.1 to 5 parts by weight and 0.01 to 5 parts by weight of an isocyanate-based crosslinking agent (C). 4. The pressure-sensitive adhesive composition according to claim 3, wherein the insoluble content (gel content) with respect to ethyl acetate is 20 to 50% by weight. 5. A pressure-sensitive adhesive product, wherein at least one of the pressure-sensitive adhesive compositions according to claim 1 is laminated on another article.