JPH07173444A - Pressure-sensitive adhesive composition - Google Patents

Abstract

PURPOSE:To provide a composition having well-balanced pressure-sensitive adhesiveness and excellent polar solvent resistance by using a radical copolymer comprising a specified polymerizable monomer, a (meth)acrylic ester, an alpha, beta-unsaturated carboxylic acid and other polymerizable monomers. CONSTITUTION:This composition comprises a copolymer obtained by radical- copolymerizing 0.1-8wt.% polymerizable monomer represented by the formula, CH.=CRCOO(CH2)m O(CO(CH2)qO)nCOC2H4COOH (wherein R is hydrogen or methyl; m is an integer of 2-10; q is an integer of 4 or 5; and n is an integer of 1-20) with 47-98.9wt.% (meth)acrylic ester of a 4-8 C alcohol, 1-5 wt.%alpha, beta-unsaturated carboxylic acid and 0-40 wt. % other polymerizable monomers.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a pressure sensitive adhesive composition. More specifically, the present invention relates to a pressure-sensitive adhesive composition suitable for a wire fixing tape in an electric device, a masking tape for baking a paint, an adhesive tape for sealing an electrolytic capacitor, and the like.

[0002]

BACKGROUND OF THE INVENTION Conventionally, as an acrylic pressure-sensitive adhesive composition for the purpose of improving the balance of adhesive properties such as adhesive force, cohesive force, tack, removability, etc., and improving the adhesive performance on curved or rough surfaces, From a main chain carbon, a pressure-sensitive adhesive composition characterized by copolymerizing a polymerizable monomer obtained by ring-opening addition of ε-caprolactone to 2-ethylhexyl (meth) acrylate (JP-A-4-309578) A pressure-sensitive adhesive composition characterized by introducing 4 to 50 mol of a side chain having a carboxyl group at a position through 3 or more carbon atoms per constituent component (JP-A-1-27471), and intramolecular A pressure-sensitive adhesive composition characterized by having 10 to 70% by weight of a polymerizable monomer having a carboxyl group in the homopolymer and having a Tg of -20 [deg.] C. or lower (Japanese Patent Laid-Open Publication No. Hei 5 (1998) -53138).
No. -112764) is known.

[0003]

However, since the above-mentioned materials have poor cohesive strength at a high temperature of about 120 ° C., they have the drawback that they peel off from the adherend with a history of time at a high temperature. Further, both of the above and those have poor resistance to solvents, particularly polar solvents such as ethylene glycol, dimethylformamide, and γ-butyrolactone, and therefore, when used in a state of being dipped in these solvents, they are applied in a relatively short time. There are problems such as peeling from the body surface.

[0004]

[Means for Solving the Problems]
Cohesive force, excellent balance of adhesive properties such as tack, particularly high cohesive force even at high temperature, and as a result of diligent studies to obtain a pressure-sensitive adhesive composition having excellent solvent resistance to polar solvents, the present invention Reached That is, the present invention provides the following general formula (1) CH ₂ = CRCOO (CH ₂ ) _m O [CO (CH ₂ ) _q O] _n COC ₂ H ₄ COOH (1) (wherein R is a hydrogen atom or a methyl group). , M is an integer of 2 to 10, q is an integer of 4 to 5, and n is an integer of 1 to 20.) Polymerizable monomer (a) 0.1 to 8% by weight, alkyl group (Meth) acrylic acid ester of alcohol having 4 to 8 carbon atoms (b) 47 to 98.9% by weight,
It is characterized by comprising a copolymer obtained by radically copolymerizing 1 to 5 parts by weight of an α, β-unsaturated carboxylic acid (c) and 0 to 40% by weight of another polymerizable monomer (d). It is a pressure sensitive adhesive composition.

The polymerizable monomer (a) in the present invention is represented by the following general formula (1) CH ₂ = CRCOO (CH ₂ ) _m O (CO (CH ₂ ) _q O) _n COC ₂ H ₄ COOH (1) (In the formula, R represents a hydrogen atom or a methyl group, m represents an integer of 2 to 10, q represents an integer of 4 to 5, and n represents an integer of 1 to 20). Here, R is a hydrogen atom or a methyl group. m represents an integer of 2 to 10, and preferably an integer of 2 to 4. q is 4 when δ-valerolactone is a constituent unit, and 5 when ε-caprolactone is a constituent unit. n represents the number of repeating units of the lactone skeleton, and is an integer of 1 to 20, preferably 1 to 10, and particularly preferably 1 to 8. n is 2
If it exceeds 0, the cohesive force at high temperature decreases. The polymerizable monomer (a) is a (meth) acrylate having a hydroxyl group (2
-Hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, etc.) is subjected to ring-opening addition of ε-caprolactone or δ-valerolactone by a known method, and then succinic anhydride is added in an equimolar amount to the hydroxyl group of the ring-opening adduct. It can be obtained by adding. (A)
As a specific example of, those shown by the following structures can be exemplified. _{CH 2 = CCH 3 COO (CH} 2) 2 OCO (CH 2) 5 OC
_{OC 2 H 4 COOH CH 2 =} CCH 3 COO (CH 2) 2 O (CO (CH 2)
₅ O) ₃ COC ₂ H ₄ COOH CH ₂ = CCH ₃ COO (CH ₂ ) ₂ O (CO (CH ₂ )
₅ O) ₅ COC ₂ H ₄ COOH CH ₂ = CHCOO (CH ₂ ) ₂ OCO (CH ₂ ) ₅ COC ₂
H ₄ COOH CH ₂ = CHCOO (CH ₂ ) ₂ O (CO (CH ₂ ) ₅ O) ₃
COC ₂ H ₄ COOH CH ₂ = CHCOO (CH ₂ ) ₂ O (CO (CH ₂ ) ₅ O) ₅
COC ₂ H ₄ COOH CH ₂ = CCH ₃ COO (CH ₂ ) ₄ O (CO (CH ₂ )
₅ O) ₃ COC ₂ H ₄ COOH CH ₂ = CCH ₃ COO (CH ₂ ) ₂ O (CO (CH ₂ )
₄ O) ₃ COC ₂ H ₄ COOH These may be used alone or in admixture of two or more.

Examples of the (meth) acrylic acid ester (b) of alcohol having 4 to 8 carbon atoms in the present invention include alkyl (meth) acrylate [n-butyl (meth) acrylate, 2-butyl (meth) acrylate, t- Butyl (meth) acrylate, pentyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, etc.], (meth) acrylate from cycloaliphatic alcohol [cyclohexyl (meth) acrylate, etc.], aromatic alcohol (Meth) acrylates such as [benzyl (meth) acrylate] and mixtures of two or more thereof. Particularly preferred among these are n-butyl acrylate, 2-ethylhexyl acrylate and mixtures thereof.

Examples of the α, β-unsaturated carboxylic acid (c) in the present invention include monobasic acids such as (meth) acrylic acid crotonic acid; and 2 such as maleic acid, itaconic acid and fumaric acid.
Examples thereof include basic acids, acid anhydrides thereof, monoalkyl esters thereof, and the like. Among these, preferred are acrylic acid, methacrylic acid, maleic anhydride and itaconic acid, and particularly preferred are acrylic acid and maleic anhydride.

The other polymerizable monomer (d) copolymerizable with (a), (b) and (c) in the present invention is a polymerizable monomer (d-) having a reactive functional group. 1)
And / or the polymerizable monomer (d-2) which has a non-reactive functional group is mentioned. Examples of the (d-1) include a polymerizable monomer having a hydroxyl group [2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate], an amide group Polymerizable monomer having [[(meth) acrylamide]], polymerizable monomer having an epoxy group [glycidyl (meth) acrylate, etc.], polymerizable monomer having an amino group [N, N-dimethylaminoethyl] (Meth) acrylate, etc., polymerizable monomer having a methylol group [N-methylolacrylamide, etc.], polymerizable monomer having a sulfonic acid group [sodium alkylallylsulfosuccinate, etc.], polymerizable having a phosphoric acid group Examples thereof include monomers such as phosphoric acid ester of 2-hydroxyethyl acrylate.

As the polymerizable monomer (d-2) having a non-reactive functional group, for example, a (meth) acrylic acid ester of an alcohol having an alkyl group having 1 to 3 carbon atoms [methyl (meth)] Acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, etc.], (meth) acrylic acid ester of alcohol having an alkyl group having 9 to 18 carbon atoms [decyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) ) Acrylate, myristyl (meth) acrylate, cetyl (meth)
Acrylate, stearyl (meth) acrylate, etc.], aromatic polymerizable monomer [styrene, vinyltoluene, etc.], polymerizable monomer having an allyl group [allyl acetate, etc.], polymerizable monomer having a nitrile group [(Meth) acrylonitrile, (meth) α-chloroacrylonitrile, etc.], halogen-containing vinyl or vinylidene-based polymerizable monomer [vinyl chloride, vinylidene chloride, etc.], vinyl ester-based polymerizable monomer [vinyl acetate, propion Vinyl acetate, vinyl butyrate, vinyl versatate, etc.], vinyl ether polymerizable monomers [vinyl ethyl ether, vinyl propyl ether, vinyl isobutyl ether, etc.] and the like.

Among the examples exemplified as (d) above, preferable examples of (d-1) are a polymerizable monomer having a hydroxyl group and a polymerizable monomer having an amide group, and particularly preferable one is Hydroxyethyl methacrylate and acrylamide. Also, (d-2)
Are vinyl ester-based polymerizable monomers and aromatic-based polymerizable monomers, and particularly preferred are vinyl acetate, vinyl propionate and styrene. The (d) can be used in combination of two or more kinds.

Constituting the copolymer in the present invention (a)
Is usually 0.1 to 8% by weight, preferably 1 to 7% by weight, particularly preferably 2 to 6% by weight. If the amount of (a) is less than 0.1% by weight, the cohesive force, particularly at high temperatures, will decrease, and if it exceeds 8% by weight, the solvent resistance to polar solvents will decrease.

The amount of (b) is usually 47-98.9% by weight,
Preferably 56-98% by weight, particularly preferably 65-
It is 95% by weight. When the amount of (b) is less than 47% by weight,
The tack and the adhesive force decrease, and when it exceeds 98.9% by weight, the cohesive force decreases and the pressure-sensitive adhesive cannot function.

The amount of (c) is usually 1-5% by weight, preferably 1.5-4.5% by weight, particularly preferably 2-4% by weight. If the amount of (c) is less than 1% by weight, the cohesive force and the adhesive force will decrease, and if it exceeds 5% by weight, the tack at room temperature will decrease.

When (d) is (d-1), the amount of (d) is usually 5% by weight or less, preferably 2% by weight or less, and in the case of (d-2), it is usually 40% by weight. It is preferably 20% by weight or less. When the amount of (d) exceeds the above range, tack and adhesive strength at room temperature decrease.

The copolymer comprising (a), (b), (c) and optionally (d) can be produced by a known polymerization method (bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, etc.). Known polymerization initiators (azo-based polymerization initiators such as azobisisobutyronitrile and azobisisovaleronitrile, benzoyl peroxide, di-t-butyl peroxide,
A peroxide type polymerization initiator such as lauryl peroxide) can be used.

The molecular weight of the copolymer comprising (a), (b), (c) and optionally (d) in the present invention is the weight average molecular weight (in terms of polystyrene) determined by gel permeation chromatography (GPC). It is usually 50,000 or more, preferably 100,000 or more, more preferably 200,000 or more. If the weight average molecular weight is less than 50,000, the cohesive force will be insufficient.

The pressure-sensitive adhesive composition of the present invention comprises, in addition to the copolymer (a), (b), (c) and (d), a known cross-linking agent for the purpose of further improving cohesive force. Agents can be used in combination. Known cross-linking agents include melamine-based cross-linking agents (melamine and hexamethylol melamine, hexamethoxymethyl melamine, melamine derivatives such as hexabutoxymethyl melamine, etc.), isocyanate-based cross-linking agents [tolylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate]. , Hexamethylene diisocyanate, 2,4- or 4,4
-Isocyanate compounds such as diphenylmethane diisocyanate and multimers thereof, adducts of isocyanate compounds to polyhydric alcohol compounds such as trimethylolpropane, blocked isocyanates (isocyanate compounds, multimers thereof and adducts and ketoxime , Blocked products with alcohol compounds such as phenol and lactam), epoxy cross-linking agents (bisphenol A / epichlorohydrin type epoxy compounds, polyalkylene glycol polyglycidyl ether, glycerin di or triglycidyl ether, tetraglycidyl xylyl) Such as diamine),
Examples thereof include metal-based cross-linking agents (oxides such as aluminum, zinc, titanium and potassium, hydroxides and carbonates, and chelate compounds with acetylacetone such as aluminum, zinc, titanium and potassium). Further, as a catalyst for accelerating the curing, an acidic catalyst such as paratoluenesulfonic acid or phosphoric acid ester can be used.

The pressure-sensitive adhesive composition of the present invention can be used by blending various known additives within a range not impairing the function of the present invention. As various additives, tackifying resins (rosin, rosin derivatives, or hydrogenated resins thereof, polyterpene resins, terpene phenol resins, xylene resins, styrene resins, coumarone / indene resins,
C5 petroleum resin, C9 petroleum resin, alicyclic hydrogenated petroleum resin, etc.), plasticizer (carboxylic acid ester represented by phthalic acid ester, chlorinated paraffin, etc.), colorant (titanium oxide, calcium carbonate, etc.) ), An anti-UV agent (such as a benzophenone-based anti-UV agent), an antistatic agent (such as a neutralized product of sulfonated polystyrene), an antifungal agent (such as cuprous oxide or a phenolic compound), an antifoaming agent (alcohol,
Silicone compounds, etc.) and the like.

The pressure-sensitive adhesive composition of the present invention can be applied to a substrate directly or by a transfer method by a method such as a usual coating method (solution coating, emulsion coating, hot melt coating). . The coating amount in that case is appropriately selected depending on the application of the adhesive processed product, but is usually 1 to 500 g / m ² . As a base material that can be used, various plastic films or resin plates such as polyethylene, polypropylene, polyethylene terephthalate, and soft polyvinyl chloride,
Examples thereof include foam, paper, woven or non-woven fabric, metal plate or foil, and wood. The material coated with the pressure-sensitive adhesive composition of the present invention is an adhesive label, a seal,
It can be used for tapes, sheets, etc.

[0020]

The present invention will be further described with reference to the following examples, but the present invention is not limited thereto. In addition, "part" in an Example shows a weight part and "%" shows weight%.

Synthesis Example 1 Ethyl acetate 135 was added to a 4-neck Kolben equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen gas inlet tube.
Part was charged and the temperature was raised to 75 ° C. Polymerizable monomer (a-1) represented by the following formula (2) [manufactured by Daicel Chemical Industries, Ltd., trade name: FM-1A] 15 parts, butyl acrylate 216
Parts, 2-ethylhexyl acrylate 60 parts, acrylic acid 9 parts and azobisisobutyronitrile (AIBN)
0.3 parts were mixed. Radical polymerization was carried out by continuously dropping the obtained monomer mixture solution into the Kolben while continuously blowing nitrogen through the dropping funnel for 4 hours. After the dropping is completed,
A solution prepared by dissolving 1.5 parts of AIBN in 66 parts of ethyl acetate was added using a dropping funnel, and 6 hours after the initiation of the polymerization, 8
It was added in three times at the 10th hour and the 10th hour. further,
After continuing the polymerization at the boiling point for 4 hours, 249 parts of toluene was added to obtain a copolymer solution (X-1). The viscosity of the (X-1) (B-type viscometer: measured at 25 ° C.) is 5,800 cp.
s, the solid content concentration was 40%, and the weight average molecular weight (in terms of polystyrene) of the copolymer by the GPC method was 570,000. _{CH 2 = CCH 3 COOC 2 H} 4 OCOC 5 H 10 OCOC 2 H 4 COOH (2)

Synthesis Example 2 Instead of the polymerizable monomer (a-1) of Synthesis Example 1, a polymerizable monomer (a-2) represented by the following formula (3) [manufactured by Daicel Chemical Co., Ltd., Trade name: FM-3A] A copolymer solution (X-2) was prepared in the same manner as in Synthesis Example 1 except that 15 parts were used. The viscosity (25 ° C) of the (X-2) is 6,300.
cps, solid content concentration was 40%, and the weight average molecular weight of the copolymer was 640,000. _{CH 2 = CCH 3 COOC 2 H} 4 O (COC 5 H 10 O) 3 COC 2 H 4 COOH (3)

Synthesis Example 3 Instead of the polymerizable monomer (a-1) of Synthesis Example 1, a polymerizable monomer (a-3) represented by the following formula (4) [manufactured by Daicel Chemical Industries, Ltd., Trade name: FM-5A] A copolymer solution (X-3) was prepared in the same manner as in Synthesis Example 1 except that 15 parts were used. The viscosity (25 ° C) of the (X-3) is 6,800.
cps, solid content concentration was 40%, and the weight average molecular weight of the copolymer was 670,000. CH ₂ = CCH ₃ COOC ₂ H ₄ O (COC ₅ H ₁₀ O) ₅ COC ₂ H ₄ COOH (4)

Synthesis Example 4 Instead of the polymerizable monomer (a-1) of Synthesis Example 1, a polymerizable monomer (a-4) represented by the following formula (5) [manufactured by Daicel Chemical Industries, Ltd., Trade name: FA-1A] A copolymer solution (X-4) was prepared in the same manner as in Synthesis Example 1 except that 15 parts were used. The viscosity (25 ° C) of the (X-4) is 5,100.
cps, solid content concentration was 40%, and the weight average molecular weight of the copolymer was 560,000. _{CH 2 = CHCOOC 2 H 4 OCOC} 5 H 10 OCOC 2 H 4 COOH (5)

Synthesis Example 5 A copolymer solution (X-5) was prepared in the same manner as in Synthesis Example 1 except that the polymerizable monomer having the following composition was used. Composition of polymerizable monomer: Polymerizable monomer (a-1) 9 parts Butyl acrylate 216 parts 2-Ethylhexyl acrylate 60 parts Acrylic acid 12 parts 2-Hydroxyethyl acrylate 3 parts Viscosity of (X-5) ( 25 ° C.) was 5,700 cps, the solid content concentration was 40%, and the weight average molecular weight of the copolymer was 610,000.

Synthesis Example 6 A copolymer solution (X-6) was prepared in the same manner as in Synthesis Example 1 except that the polymerizable monomer having the following composition was used. Composition of polymerizable monomer: Polymerizable monomer (a-1) 15 parts Butyl acrylate 195 parts 2-Ethylhexyl acrylate 45 parts Acrylic acid 9 parts Vinyl acetate 36 parts Viscosity of the (X-6) (25 ° C) Was 6,500 cps, the solid content concentration was 40%, and the weight average molecular weight of the copolymer was 700,000.

Synthetic Example 7 A copolymer solution (X-7) was prepared in the same manner as in Synthetic Example 1 except that a polymerizable monomer having the following composition was used. Composition of polymerizable monomer: Polymerizable monomer (a-1) 15 parts Butyl acrylate 201 parts 2-Ethylhexyl acrylate 60 parts Acrylic acid 9 parts Styrene 15 parts The viscosity (25 ° C) of the (X-7) is 5,500 cps, solid content concentration was 40%, and the weight average molecular weight of the copolymer was 530,000.

Comparative Synthetic Example 1 A comparative copolymer solution (Y-1) was prepared in the same manner as in Synthetic Example 1 except that a polymerizable monomer having the following composition was used. Composition of polymerizable monomer: butyl acrylate 231 parts 2-ethylhexyl acrylate 60 parts acrylic acid 9 parts The viscosity (25 ° C.) of (Y-1) is 6,500 cps, the solid content concentration is 40%, The weight average molecular weight was 630,000.

Comparative Synthesis Example 2 Instead of the polymerizable monomer (a-1) of Synthesis Example 6, a polymerizable monomer (a-5) represented by the following formula (6) [manufactured by Daicel Chemical Industries, Ltd.] , Trade name: FM-1] was used to prepare a copolymer solution (Y-2) in the same manner as in Synthesis Example 1. The viscosity (25 ° C.) of the (Y-2) is 8,500.
cps, solid content concentration was 40%, and the weight average molecular weight of the copolymer was 710,000. _{CH 2 = CCH 3 COOC 2 H} 4 OCOC 5 H 10 OH (6)

Comparative Synthetic Example 3 A comparative copolymer solution (Y-3) was prepared in the same manner as in Synthetic Example 1 except that a polymerizable monomer having the following composition was used. Composition of polymerizable monomer: Polymerizable monomer (a-1) 60 parts Butyl acrylate 150 parts 2-Ethylhexyl acrylate 45 parts Acrylic acid 9 parts Vinyl acetate 36 parts Viscosity of the (Y-3) (25 ° C) Is 7,700 cps, the solid content is 40%, and the weight average molecular weight of the copolymer is 69.
It was good.

Comparative Synthetic Example 4 A comparative copolymer solution (Y-4) was prepared in the same manner as in Synthetic Example 1 except that a polymerizable monomer having the following composition was used. Composition of polymerizable monomer: Polymerizable monomer (a-1) 15 parts Butyl acrylate 195 parts 2-Ethylhexyl acrylate 90 parts (Y-4) viscosity (25 ° C) is 4,300 cps, solid content concentration is At 40%, the weight average molecular weight of the copolymer was 510,000.

Examples 1 to 7, Comparative Examples 1 to 4 (X-1) to (X-7) prepared in Synthesis Examples 1 to 7 and (Y-1) to ((Comparative Synthesis Examples 1 to 4). To each 100 parts of Y-4), 2.5 parts of a tolylene diisocyanate adduct of trimethylolpropane [manufactured by Nippon Polyurethane Co., Ltd., trade name: Coronate L] was added as a crosslinking agent,
After uniformly mixing, apply it to a polyethylene terephthalate film so that the dry film thickness is 20 μm, and apply 100 ° C.
It was dried under the condition of × 2 minutes and further cured at 50 ° C. for 5 days. This coated sheet is cut into a test piece with a predetermined width,
Using this, various performance tests were carried out by the following methods to evaluate cohesive force at room temperature, adhesive force, tack, cohesive force at high temperature and solvent resistance. The results are shown in Table 1.

Performance Test Method 1. Room temperature holding power (cohesive strength) test A 25 mm x 25 mm sample piece was attached to a stainless steel plate (SUS304) and pressed back and forth once with a 5 kg roller,
After standing for 1 hour under the condition of 23 ° C x 65% RH, 1k
Shifted after 24 hours (unit: mm)
Alternatively, the time (unit: minutes) until the test piece falls was measured. 2. High temperature holding power (cohesive force) test A 25 mm x 25 mm sample piece was attached to a stainless steel plate (SUS304) and pressed back and forth with a 5 Kg roller for one reciprocation.
After left in an atmosphere of 120 ° C. for 1 hour, a weight of 200 g was applied, and a displacement distance (unit: mm) after 4 hours or a time until the test piece fell (unit: min) was measured. 3. Measurement of softening temperature (confirmation of high-temperature cohesive force) A 25 mm x 25 mm sample piece was attached to a stainless steel plate (SUS304), and a reciprocating pressure was applied by a 5 Kg roller,
After leaving for 1 hour under the condition of 23 ° C x 65% RH, 20
A weight of 0 g was applied, the temperature was raised at a rate of 1 ° C. in 2 minutes, and the temperature (unit: ° C.) when the test piece dropped was measured. 4. Adhesion test A 25 mm wide sample piece is attached to a stainless steel plate (SUS304), and JIS Z-2 is used under the conditions of 23 ° C x 65% RH.
A prescribed 180 ° peel test (unit: g) was performed on 307. 5. Tack measurement J.K. under an atmosphere of 23 ° C. × 65% RH. Tack was measured by the Dow method. 6. Solvent resistance test A 20 mm wide sample piece was wound around a glass rod with a diameter of 4 mm, left in an atmosphere of 23 ° C for 1 hour, then immersed in dimethylformamide (DMF) of 25 ° C, and a sample piece after 24 hours The presence or absence of peeling and plow was observed. The number of test samples was N = 5. A similar test was conducted using γ-butyrolactone (γBL). Judgment criteria for solvent resistance test Peeling off sample pieces, no puffing -------------------- Some puffs occur on end faces of sample pieces --------------- The sample piece is peeled off from the glass rod in an area of ½ or more. -3 Specimen piece completely detached from glass rod (1-2 pieces) ---- 2 Specimen piece or glass rod completely detached (3-5 pieces) ----------- 1

[0034]

[Table 1]

[0035]

The pressure-sensitive adhesive composition of the present invention has the following features. It has a high cohesive force even at high temperatures. Excellent resistance to polar solvents. Excellent balance of adhesive properties such as adhesive strength, cohesive strength and tack. Because of the above effects, the pressure-sensitive adhesive composition of the present invention is suitable for a wire fixing tape in electric equipment, which has a relatively high temperature, and a masking tape for baking a paint. Further, since it has excellent resistance to polar solvents, it is suitable for an electrolytic capacitor sealing tape or the like used in a solvent atmosphere, and is extremely useful industrially.

Claims (1)

[Claims] 1. As a structural unit, the following general formula (1) CH ₂ ═CRCOO (CH ₂ ) _m O (CO (CH ₂ ) _q O) _n COC ₂ H ₄ COOH (1) (wherein R is hydrogen Atom or a methyl group, m is an integer of 2 to 10, q is an integer of 4 to 5, and n is an integer of 1 to 20). %, (Meth) acrylic acid ester (b) of alcohol having 4 to 8 carbon atoms in the alkyl group (b) 47 to 98.9% by weight,
It is characterized by comprising a copolymer obtained by radically copolymerizing 1 to 5 parts by weight of an α, β-unsaturated carboxylic acid (c) and 0 to 40% by weight of another polymerizable monomer (d). Pressure sensitive adhesive composition.