JPH05271634A - Water-dispersed pressure-sensitive adhesive composition, pressure-sensitive tape or sheet, and sticking structure - Google Patents

Abstract

PURPOSE:To obtain an adhesive composition having high initial tack and not decreasing in adhesion to a flexible vinyl chloride resin product containing a compound having an epoxy group in the molecule with time by using a specified acrylic copolymer as the principal component. CONSTITUTION:This composition is prepared by using as the principal component an acrylic copolymer obtained by emulsion-copolymerizing a monomer mixture mainly consisting of at least one alkyl (meth)acrylate monomer of the formula: CH2=CR1COOR2 (wherein R1 is H or CH3; and R2 is 1-12C alkyl) with 3-10wt.%, based on the monomer mixture, at least one monomer selected from among N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine and n-isopropylacrylamide.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an acrylic water-dispersible pressure-sensitive adhesive composition suitable for sticking to a soft vinyl chloride resin product containing a compound having an epoxy group in the molecule.
The present invention relates to an adhesive tape or sheet and a sticking structure.

[0002]

2. Description of the Related Art A soft vinyl chloride resin (hereinafter abbreviated as "soft vinyl") resin is used as a base material of an adhesive tape or sheet using an acrylic adhesive composition, and an acrylic resin is used for a soft vinyl resin product. A pressure-sensitive adhesive tape or sheet provided with a pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition, or a soft vinyl resin product on an adherend using a double-sided adhesive tape, or an acrylic resin on a soft vinyl resin product. When a pressure-sensitive adhesive layer made of a pressure-sensitive adhesive composition is provided, the adhesive performance of the pressure-sensitive adhesive layer is significantly reduced with the passage of a long time, and, for example, the soft vinyl resin product that is pasted off from the adherend. was there.

It has been conventionally considered that the cause of this problem is that the plasticizer in the soft vinyl resin migrates into the pressure-sensitive adhesive layer over time, and the cohesive force of the pressure-sensitive adhesive is significantly reduced. Various improvements have been made in acrylic emulsion adhesives based on this idea.

For example, in JP-A-61-268782, a polyfunctional monomer having two or more ethylenic double bonds in the molecule is mixed in an acrylic pressure-sensitive adhesive, and the mixture is allowed to react with the inside of the emulsion particles. A method of preventing the decrease in cohesive force by providing a cross-linked structure to
Japanese Patent No. 505 proposes a method of crosslinking emulsion particles having a two-layer structure between layers.

However, these conventional techniques have no effect on soft vinyl resin products containing a compound having an epoxy group in the molecule, such as epoxidized soybean oil, and
Even when the plasticizing substance is not a low molecular weight plasticizer such as dioctyl phthalate, but a polymer plasticizer such as a polyester plasticizer which has been conventionally said to have no transferability to the pressure-sensitive adhesive layer is used. , It became clear in the study of the present inventors that the adhesive force to the surface of the soft vinyl resin product is drastically reduced,
The reason for this is that α and β used in the above publication
It was found that the crosslinking proceeds as the acid group derived from unsaturated carboxylic acid or the like is bonded to the epoxy group in the soft vinyl resin and the adhesive is largely unsuitable.

On the other hand, from the viewpoint of protection of the global environment and resource saving, it is desired to make the acrylic pressure-sensitive adhesive solvent-free, and instead of the conventional solvent-type acrylic pressure-sensitive adhesive, a hot-melt type, an ultraviolet block polymerization type or The water-dispersion type is becoming more and more popular.

[0007]

DISCLOSURE OF THE INVENTION The present inventors have found that an adhesive having a high initial adhesive strength and having no deterioration in adhesive performance over time to a soft resin containing a compound having an epoxy group in the molecule. As a result of diligent examination of the monomer composition of the acrylic copolymer for the purpose of providing a composition, a pressure-sensitive adhesive tape or sheet, and a sticking structure, N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine and N-isopropylacrylamide were used. It was found that one or more kinds of monomers selected from the group consisting of the following groups exert a very excellent effect as a cohesive force-imparting component, and as a result of further studies, surprisingly, the content of active hydrogen-containing monomers such as acrylic acid was found. The lower the value is, the more the decrease in adhesive strength with time to the soft vinyl resin containing the compound having an epoxy group is suppressed. Findings were obtained say. The present invention has been completed based on such findings.

[0008]

The invention according to claim 1 of the present application is a water-dispersible pressure-sensitive adhesive composition for a soft vinyl resin product, which comprises a compound having an epoxy group in the molecule, and has the general formula C
At least one alkyl (meth) acrylate monomer represented by H ₂ = CR ₁ COOR ₂ (wherein R ₁ represents hydrogen or a methyl group, R ₂ represents an alkyl group having 1 to 12 carbon atoms), Obtained by emulsion-copolymerizing 3 to 10% by weight (in the monomer component) of at least one monomer selected from the group consisting of N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine and N-isopropylacrylamide as a main component monomer. A water-dispersed pressure-sensitive adhesive composition comprising an acrylic copolymer as a main component.

According to the invention of claim 2 of the present application, the water-dispersible pressure-sensitive adhesive composition according to claim 1 comprises at least one selected from the group consisting of a carboxyl group-containing monomer, a hydroxyl group-containing monomer and a sulfonic acid group-containing monomer. Functional monomer 0.1
1 to 1% by weight is added to the main component monomer and emulsion-copolymerized to be contained. The invention of claim 3 of the present application is an adhesive tape or sheet obtained by laminating an adhesive layer comprising the adhesive composition of claim 1 or 2 on at least one surface of a substrate. The invention of claim 4 of the present application is characterized in that a soft resin product containing a compound having an epoxy group in the molecule is attached to an adherend via the adhesive tape or sheet of claim 3. It is a pasting structure.

As the compound having an epoxy group in the molecule contained in the soft vinyl resin, it is described in "Polyvinyl chloride-its basics and applications" (published by Nikkan Kogyo Shimbun, 1988). In addition, epoxidized animal and vegetable oils such as epoxidized soybean oil and epoxidized linseed oil, epoxidized fatty acid esters, and epoxidized alicyclic compounds such as epoxidized tetrahydrophthalate as stabilizers and secondary plasticizers for soft vinyl resins. Examples thereof include compounds, bisphenol A diglycidyl ether, and epoxidized polybutadiene.

The soft vinyl resin usually has a degree of polymerization of 800 to 1.
Vinyl chloride resin of 500, phthalic acid ester type such as dioctyl phthalate, aliphatic dibasic acid ester such as di-2-ethylhexyl adipate, trimellitic acid ester, phosphoric acid ester, polyester type or the above-mentioned epoxy type plastic One or more kinds of agents are mixed, and generally several parts by weight to hundreds of tens parts by weight of a plasticizer are contained with respect to 100 parts by weight of a resin.

The alkyl (meth) acrylate monomers used in the present invention have the general formula CH ₂ ═CR ₁ C
Represented by OOR ₂ , wherein R ₁ is hydrogen or a methyl group, R 1
₂ is an alkyl group having 1 to 12 carbon atoms, that is,
Methyl group, ethyl group, n-butyl group, n-octyl group,
2-ethylhexyl group, isooctyl group, at least one selected from monomers such as isononyl group, especially, n-butyl acrylate is preferably used, and n-butyl acrylate 95 wt% or less, n- A combination system comprising 5 to 30% by weight of the alkyl (meth) acrylate monomer represented by the above general formula other than butyl acrylate is particularly preferably used.

Examples of the alkyl (meth) acrylate monomer represented by the above general formula other than n-butyl acrylate include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth). ) Acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate and the like are used, and ethyl acrylate is particularly preferably used.

When the number of carbon atoms of the alkyl group of the alkyl (meth) acrylate monomer exceeds 12, the glass transition temperature becomes high and the adhesive strength is lowered. The content ratio of alkyl (meth) acrylate in all the copolymerization components is 9
It must be 7% by weight (in the monomer component) or less,
Preferably, it is 70 to 97% by weight (in the monomer component). When the content ratio exceeds 97% by weight (in the monomer component), the cohesive force of the pressure-sensitive adhesive is low and the pressure-sensitive adhesive force is low, and the physical properties of the soft vinyl resin containing a compound having an epoxy group in the molecule deteriorate with time. It gets bigger.

The content of one or more kinds of monomers selected from N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine and N-isopropylacrylamide used in the present invention in all copolymer components is 3 to.
10 wt% (in the monomer component), preferably 5 to
It is 8% by weight (in the monomer component).

When the content is less than 3% by weight (in the monomer component), the soft vinyl chloride resin containing a compound having an epoxy group in the molecule has a low cohesive force and low adhesive force. As a result, the deterioration of physical properties with time becomes large. On the other hand, when it exceeds 10% by weight (in the monomer component), the initial adhesive properties after application cannot be balanced.

The mechanism of such a suitable combination with an alkyl (meth) acrylate is not yet clear, but a suitable combination with N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine, N-isopropylacrylamide, etc. The initial cohesive force, viscoelastic behavior, polarity, and cohesive force after migration of the plasticizer based on the affinity with the plasticizer, viscoelastic behavior, polarity, etc. form suitable regions in the pressure-sensitive adhesive within the scope of the present invention. It is estimated that

Further, in the present invention, an unsaturated monomer copolymerizable with an alkyl (meth) acrylate is optionally used, and specific examples thereof include vinyl acetate, styrene, (meth) acrylamide and the like. Examples include monomers that increase the glass transition temperature. Also,
To increase the polymerization stability of the emulsion, 0.1 to 1 of a carboxyl group-, hydroxyl group-, or sulfonic acid group-containing monomer is added.
You may copolymerize in the range of weight%. However, the α, β-unsaturated carboxylic acid which forms a chemical bond with the epoxy compound should not exceed 0.5% by weight in the acrylic copolymer.

The acrylic copolymer of the present invention can be polymerized by a conventionally known emulsion polymerization method such as a batch charging method, a monomer sequential addition method, an emulsion monomer sequential addition method and a seed polymerization method. The polymerization initiator is potassium persulfate, ammonium persulfate, hydrogen peroxide, and a redox initiator in which these are used in combination with a reducing agent, 2,2′-azobis (N, N ′).
-Dimethylene isobutylamidine), 2,2'-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide} or other water-soluble azo compound, or benzoyl peroxide , 2, 2 '
-A known initiator such as an oil-soluble initiator such as azobisisobutyronitrile may be used alone or in combination as appropriate. These are usually 0.05 to 1 with respect to 100 parts by weight of the monomer.
Used in parts by weight.

As the emulsifier, anionic emulsifiers such as sodium lauryl sulfate and sodium dodecylbenzene sulfonate, nonionic emulsifiers such as polyoxyethylene nonylphenyl ether and polyoxyethylene sorbitol fatty acid ester, or water-soluble polyvinyl alcohol and the like. A method of using a polymer as a protective colloid may be appropriately used alone or in combination.

The pressure-sensitive adhesive of the present invention should be appropriately crosslinked in the same manner as conventional acrylic pressure-sensitive adhesives in order to maintain the physical properties at high temperatures and the properties when a plasticizer is contained. Electron beam irradiation method, thermal cross-linking method of peroxides such as benzoyl peroxide, and commonly used methods include blocked isocyanate cross-linking agent, epoxy cross-linking agent, melamine cross-linking agent, aziridine cross-linking agent, metal cross-linking method. A method in which an agent or a polyfunctional monomer is added to crosslink can be adopted.

When such a cross-linking agent is used, hydroxyethyl (meth) is previously added to the acrylic copolymer.
Monomers having -OH group such as acrylate and hydroxypropyl methacrylate, and -COO such as acrylic acid
Although a monomer having an H group is often copolymerized, when an α, β-unsaturated carboxylic acid is used as a crosslinking origin monomer of an acrylic copolymer, it is preferable that the amount is as small as possible, and the content thereof is 0.5. It should be below wt% (in the monomer component), preferably below 0.3 wt%. The preferred degree of crosslinking of the pressure-sensitive adhesive is 30 to 90% by weight of the acrylic copolymer, more preferably 40 to 80% by weight, based on the insoluble content (gel fraction) after immersion in tetrahydrofuran.

In the present invention, the tackifying resin can be mixed with the tackifying resin, if necessary, to control the physical properties of the tackifying resin. As the tackifying resin, conventionally known resins such as natural resin rosin derivative system, terpene phenol resin system, synthetic resin system aromatic petroleum resin system, coumarone indene resin system, phenol resin system and xylene resin system can be used. However, these tackifying resins are added to 30 parts by weight with respect to 100 parts by weight of the acrylic copolymer.
Less than or equal to parts by weight is preferred. If it exceeds this, the storage stability and coating stability of the emulsion tend to deteriorate.

These tackifying resins may be added to the reactor at the start of the polymerization of the acrylic copolymer,
The monomers may be added simultaneously with the sequential addition of the monomers, or may be added after the completion of the polymerization. Preferably, a method of adding a pre-emulsified tackifying resin after completion of polymerization is recommended. Further, in order to improve storage stability and coating workability, a pH adjusting agent, a thickener, a defoaming agent or the like may be added.

The emulsion in the present invention can be used by adjusting the solid content of the copolymer to 40 to 70% by weight. In order to increase the productivity, it is desirable that the solid content is as high as possible. However, if the solid content is excessively increased, the polymerization stability will be impaired. Therefore, it is preferably 50 to 65% by weight. The average particle size of the emulsion is preferably 0.1 to 3 μm, more preferably 0.4 to 1 μm. If it is less than 0.1 μm, the viscosity of the dispersion becomes high and at the same time thixotropy becomes high, and the coating stability tends to be impaired, and if it exceeds 3 μm, the storage stability tends to decrease.

The pressure-sensitive adhesive tape or sheet having the pressure-sensitive adhesive layer according to the present application may be based on a soft vinyl resin,
The soft vinyl resin product may be attached to an adherend.

The pressure-sensitive adhesive tape may have a pressure-sensitive adhesive layer on one side or may be a so-called double-sided tape having a pressure-sensitive adhesive layer on both sides of the substrate. In the case of a double-sided tape shape, it is necessary to provide a pressure-sensitive adhesive layer made of the adhesive composition of the present invention on at least one side.

As the substrate, paper, non-woven fabric, plastic film made of polyester resin or polyolefin resin, polyolefin resin, polyurethane resin, polychloroprene resin, soft vinyl resin (preferably having the above composition), acrylic resin, etc. A plastic foam made of is used.

Further, it may be a so-called non-support type pressure-sensitive adhesive sheet having no base material layer. In the pressure-sensitive adhesive tape or sheet of the present invention, it is important that the pressure-sensitive adhesive layer in contact with the soft resin body containing a compound having an epoxy group in the molecule is the pressure-sensitive adhesive composition according to claim 1. Therefore, the form of the pressure-sensitive adhesive tape or sheet of the present invention may be a single-sided pressure-sensitive adhesive tape or sheet, or a double-sided pressure-sensitive adhesive tape or sheet in which the composition of the pressure-sensitive adhesive layer on the other surface is different.

[0030]

In the present invention, a specific alkyl (meth) acrylate monomer and a required amount of N-vinylpyrrolidone,
Since the main component is an acrylic copolymer obtained by copolymerizing with one or more monomers selected from the group consisting of N-vinylcaprolactam, acryloylmorpholine and N-isopropylacrylamide, the adhesiveness at the initial stage of application Excellent in physical properties, and even if the compound having an epoxy group in the molecule moves from the soft resin product to the pressure-sensitive adhesive layer,
Since it does not substantially contain α, β-unsaturated carboxylic acid having reactive active hydrogen, it does not undergo a chemical modification action,
Provided is a pressure-sensitive adhesive composition capable of suppressing a decrease in pressure-sensitive adhesive performance.

Further, the pressure-sensitive adhesive tape or sheet of the present invention is one in which a pressure-sensitive adhesive layer made of the above-mentioned pressure-sensitive adhesive composition is laminated on at least one surface of a substrate, and therefore the pressure-sensitive adhesive property at the initial stage of application is excellent, and , When this surface is attached to a soft vinyl resin product containing a compound having an epoxy group in the molecule, or when the soft vinyl resin product is attached to an adherend, by sticking this surface to the product side, The deterioration of the adhesive performance with time becomes small.

Further, when a soft resin product containing a compound having an epoxy group in the molecule is attached to an adherend through the above-mentioned adhesive tape or sheet, the adhesive structure has little deterioration in adhesive performance over time. Becomes

[0033]

EXAMPLES Examples of the present invention will be described below. Example 1 94.5 parts by weight of n-butyl acrylate (BA),
A mixture of 5 parts by weight of N-vinylpyrrolidone (NVP) and 0.5 part by weight of 2-hydroxyethyl methacrylate (2HEMA) was mixed with 30 parts by weight of deionized water in which 0.8 part by weight of sodium lauryl sulfate as an emulsifier was dissolved. The emulsified monomer was adjusted by stirring.

Next, in a reactor equipped with a thermometer, a stirrer, a cooling tube and a dropping funnel, 0.3 parts by weight of potassium persulfate was added to 40 parts by weight of deionized water and stirred, and the liquid temperature was refluxed under nitrogen gas. Was maintained at 65 ° C., 2 parts by weight of the emulsified monomer was added. After 20 minutes, the liquid temperature was raised to 70 ° C., and the remaining emulsified monomer was added dropwise over 3 hours for reaction. Liquid temperature of 8
The temperature was raised to 5 ° C., the reaction was carried out at the same temperature for 2 hours, and the mixture was cooled, and then the pH of the obtained emulsion was adjusted to 7.5 with 25% aqueous ammonia to obtain a desired aqueous dispersion of the copolymer. It was

This pressure-sensitive adhesive aqueous dispersion was dried on a 38 μm-thick release-treated polyester film to give a film thickness of 60.
After being coated so as to have a thickness of μm and dried at 100 ° C. for 5 minutes, it was transferred onto both surfaces of a nonwoven fabric having a basis weight of 14 g to prepare a double-sided adhesive tape. The following performance test was conducted using this double-sided adhesive tape.

Performance test 180 degree peeling force Vinyl chloride resin (polymerization degree 1100) 100 as adherend
Soft vinyl resin plate (30 × 80 × 5 m) consisting of 50 parts by weight, dioctyl phthalate 50 parts by weight, epoxidized soybean oil 2 parts by weight, tin-based liquid stabilizer 3 parts by weight, and calcium carbonate 15 parts by weight.
m) was used. A 20 mm wide double-sided pressure-sensitive adhesive tape test piece having one adhesive surface backed with a 25 μm-thick polyethylene terephthalate film was reciprocated once with a 2 kg roller to adhere to this adherend, and after 20 minutes, JIS Z
The 180-degree peeling force was measured according to 0237.

A test piece prepared in the same manner was accelerated in an atmosphere of 80 ° C. to transfer the plasticizer in the adherend into the pressure-sensitive adhesive layer, and then the 180 ° peeling force was measured. I examined the change of.

After the adhesive tape was attached to the adherend by the same operation as the holding force to accelerate aging, the holding force was measured under a 40 ° C. atmosphere under a load of 1 kg in accordance with JIS Z0237. In this test, the application area was 25 mm × 25 mm, and the measurement was stopped after 72 hours.

Example 2 The emulsifier was polyoxyethylene nonyl phenyl ether (trade name "Neugen EA140": manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.).
0.6 part by weight, sulfone group-containing reactive emulsifier (trade name "Aqualon HS-10": manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) 0.6
Parts by weight, BA 45 parts by weight, 2-ethylhexyl acrylate (2EHA) 44.7 parts by weight, NVP 10 parts by weight, N-methylol acrylamide (NMAM) 0.3
Polymerization was carried out in the same manner as in Example 1 as parts by weight to produce an adhesive tape, and its performance was evaluated.

Example 3 The monomer composition was 86.5 parts by weight of 2EHA, 10 parts by weight of butyl methacrylate (BMA), and 3 parts by weight of NVP.
Lauryl mercaptan (LM) 0.0 as chain transfer agent
An adhesive liquid was obtained in the same manner as in Example 2 except that 5 parts by weight was used. After adding 10 parts by weight of an emulsified rosin-based tackifying resin (trade name "Super Ester E740" manufactured by Arakawa Chemical Co., Ltd.) to this adhesive liquid, an aziridine cross-linking agent (trade name "Chemite DZ22E" manufactured by Nippon Shokubai Chemical Co., Ltd.)
After adding and mixing 0.2 parts by weight, the same operation as in Example 1 was performed to obtain an adhesive tape, and the performance thereof was evaluated.

Comparative Example 1 The monomer composition was isooctyl acrylate (IOA) 9
3 parts by weight, 7 parts by weight of acrylic acid (AAc), LM
An adhesive tape was obtained in the same manner as in Example 1 except that the amount was 0.05 part by weight, and its performance was evaluated.

Comparative Example 2 The monomer composition was 90 parts by weight of BA, 8 parts by weight of NVP, and AA.
An adhesive tape was obtained in the same manner as in Example 1 except that the amount was c2 parts by weight, and its performance was evaluated.

Comparative Example 3 Monomer composition was 78.7 parts by weight BA, 20 parts by weight ethyl acrylate (EA), 1 part by weight NVP, NMAM0.
An adhesive tape was obtained in the same manner as in Example 1 except that the amount was 3 parts by weight, and its performance was evaluated.

The results of Examples 1 to 3 and Comparative Examples 1 to 3 are summarized in Table 1.

[Table 1]

Example 4 A double-sided pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that 5 parts by weight of N-vinylcaprolactam (NVC) was used instead of 5 parts by weight of NVP, and its performance was evaluated.

Example 5 A double-sided pressure-sensitive adhesive tape was produced in the same manner as in Example 2 except that 10 parts by weight of NVC was used instead of 10 parts by weight of NVP, and its performance was evaluated.

Example 6 A double-sided pressure-sensitive adhesive tape was produced in the same manner as in Example 3 except that 3 parts by weight of NVC was used instead of 3 parts by weight of NVP.
The performance was evaluated.

Comparative Example 4 An adhesive tape was obtained in the same manner as in Example 4 except that the monomer composition was 93 parts by weight of IOA, 7 parts by weight of AAc and 0.05 part by weight of LM, and the performance thereof was evaluated.

Comparative Example 5 Monomer composition of 90 parts by weight of BA, 8 parts by weight of NVC, AA
An adhesive tape was obtained in the same manner as in Example 4 except that the amount was c2 parts by weight, and its performance was evaluated.

Comparative Example 6 Monomer composition was changed to BA 78.7 parts by weight, EA 20 parts by weight,
An adhesive tape was obtained in the same manner as in Example 5 except that 1 part by weight of NVC and 0.3 part by weight of NMAM were used, and its performance was evaluated.

The results of Examples 4 to 6 and Comparative Examples 4 to 6 are summarized in Table 2.

[Table 2]

Example 7 A double-sided pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that the monomer composition was 91.5 parts by weight of BA, 8 parts by weight of acryloylmorpholine (ACMO), and 0.5 parts by weight of 2HEMA. Was evaluated.

Example 8 A double-sided pressure-sensitive adhesive tape was produced in the same manner as in Example 2 except that 10 parts by weight of ACMO was used instead of 10 parts by weight of NVP, and its performance was evaluated.

Example 9 A double-sided pressure-sensitive adhesive tape was produced in the same manner as in Example 3 except that the monomer composition was 84.5 parts by weight of 2EHA, 10 parts by weight of BMA, 5 parts by weight of ACMO, and 0.5 part by weight of AAc. evaluated.

Comparative Example 7 An adhesive tape was obtained in the same manner as in Example 7 except that the monomer composition was 93 parts by weight of IOA, 7 parts by weight of AAc, and 0.05 part by weight of LM, and the performance was evaluated.

Comparative Example 8 Monomer composition of 90 parts by weight of BA, 8 parts by weight of ACMO, A
An adhesive tape was obtained in the same manner as in Example 7 except that 2 parts by weight of Ac was used, and its performance was evaluated.

Comparative Example 9 Monomer composition of BA 78.7 parts by weight, EA 20 parts by weight,
An adhesive tape was obtained in the same manner as in Example 8 except that 1 part by weight of ACMO and 0.3 part by weight of NMAM were used, and its performance was evaluated.

The results of Examples 7-9 and Comparative Examples 7-9 are summarized in Table 3.

[Table 3]

Example 10 91.5 parts by weight of monomer composition, 8 parts by weight of N-isopropylacrylamide (NIPAM), 2HEMA
A double-sided pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that the amount was 0.5 part by weight, and the performance thereof was evaluated.

Example 11 A double-sided pressure-sensitive adhesive tape was produced in the same manner as in Example 2 except that 10 parts by weight of NVPAM was used instead of 10 parts by weight of NVP, and its performance was evaluated.

Example 12 A double-sided pressure-sensitive adhesive tape was produced in the same manner as in Example 3 except that the monomer composition was 84.5 parts by weight of 2EHA, 10 parts by weight of BMA, 5 parts by weight of NIPAM, and 0.5 part by weight of AAc. evaluated.

Comparative Example 10 An adhesive tape was obtained in the same manner as in Example 10 except that the monomer composition was 93 parts by weight of IOA, 7 parts by weight of AAc, and 0.05 part by weight of LM, and the performance was evaluated.

Comparative Example 11 Monomer composition of BA 90 parts by weight, NIPAM 8 parts by weight,
An adhesive tape was obtained in the same manner as in Example 10 except that 2 parts by weight of AAc was used, and its performance was evaluated.

Comparative Example 12 Monomer composition of BA 78.7 parts by weight, EA 20 parts by weight,
An adhesive tape was obtained in the same manner as in Example 11 except that 1 part by weight of NIPAM and 0.3 part by weight of NMAM were used, and the performance thereof was evaluated.

Examples 10 to 12 and Comparative Examples 10 to 1
The results of 2 are summarized in Table 4.

[Table 4]

As is clear from Tables 1 to 4, it is recognized that the pressure-sensitive adhesive of the present invention is superior in adhesive strength and holding power after heat aging as compared with the conventional pressure-sensitive adhesive, and that the adhesive performance over time is stable.

[0067]

The pressure-sensitive adhesive composition according to the present invention comprises an acrylic resin containing a specific amount of at least one monomer selected from the group consisting of N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine and N-isopropylacrylamide. An acrylic water-dispersed pressure-sensitive adhesive composition containing a copolymer, wherein a substrate such as a pressure-sensitive adhesive tape or pressure-sensitive adhesive sheet or an adherend to be attached contains a compound having an epoxy group in its molecule. When it is made of a resin, it is useful because it can effectively suppress the deterioration of the adhesive performance even when the compound migrates to the adhesive layer, and therefore, an adhesive tape, sheet and laminated structure using the same. Guarantees a high adhesion reliability for a soft resin containing a compound having an epoxy group in the molecule. Further, since it is a water-dispersed type, it is a non-polluting pressure-sensitive adhesive composition adapted to the problem of environmental pollution.

Claims (4)

[Claims] 1. A water-dispersible pressure-sensitive adhesive composition for a soft vinyl chloride-based resin product containing a compound having an epoxy group in the molecule, wherein the composition has the general formula CH ₂ = CR ₁ COOR ₂ (wherein R ₁ Is hydrogen or a methyl group, and R ₂ represents an alkyl group having 1 to 12 carbon atoms), N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine, and At least one monomer selected from the group consisting of N-isopropylacrylamide 3-10
A water-dispersed pressure-sensitive adhesive composition comprising an acrylic copolymer as a main component, which is obtained by emulsion copolymerization with wt% (in the monomer component) as a main component monomer. 2. Emulsion copolymerization in which 0.1 to 1% by weight of one or more functional monomers selected from the group consisting of a carboxyl group-containing monomer, a hydroxyl group-containing monomer and a sulfonic acid group-containing monomer is added to the main component monomer. The water-dispersed pressure-sensitive adhesive composition according to claim 1, wherein 3. A pressure-sensitive adhesive tape or sheet obtained by laminating a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition according to claim 1 or 2 on at least one surface of a substrate. 4. A sticking structure characterized in that a soft vinyl chloride resin product containing a compound having an epoxy group in its molecule is stuck to an adherend via the adhesive tape or sheet according to claim 3. body.