JPH06145623A - Water-dispersed acrylic tacky adhesive and tacky adhesive tape or sheet produced by using the adhesive - Google Patents

Abstract

PURPOSE:To obtain the subject tacky adhesive having low viscosity and excellent polymerization stability, mechanical stability, water resistance and adhesivity and useful for tacky adhesive tape, sheet, etc., by carrying out the emulsion polymerization of a specific alkyl acrylate and a specific carboxyl- containing monomer in an aqueous medium. CONSTITUTION:The objective tacky adhesive is produced from a monomer mixture consisting of (A) an alkyl (meth)acrylate having 4-14C alkyl group as a main component and (B) one or more carboxyl-containing monomers copolymerizable with the component A and expressed by formula I, formula II or formula III (R<1> is H or methyl; R<2> is ethylene or arylene; the average of (n) is 1-2 for formula II and 1-3 for formula III) such as acrylic acid dimer by carrying out the emulsion polymerization of the monomer mixture in an aqueous medium using a surfactant having a polymerizable double bond as an emulsifier.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-dispersible acrylic pressure-sensitive adhesive and a pressure-sensitive adhesive tape or sheet using this pressure-sensitive adhesive.

[0002]

2. Description of the Related Art Adhesive tapes or sheets are generally
It is manufactured by applying a pressure-sensitive adhesive to a substrate made of paper, non-woven fabric, synthetic resin film, metal foil, etc. and drying.

Solvent-type or water-dispersion acrylic adhesives are used as the adhesives. Among them, the water-dispersible acrylic adhesive does not contain an organic solvent, and therefore is hygienic, has no fear of air pollution or fire, and has been increasingly used from the viewpoint of resource saving.

Conventionally, this type of water-dispersible acrylic pressure-sensitive adhesive has a main component of (meth) acrylic acid alkyl ester, a mixed monomer with another monomer copolymerizable therewith, and a surfactant as an emulsifier. It is produced by emulsion polymerization in an aqueous medium.

The (meth) acrylic acid alkyl ester component mainly gives tackiness, and for example, n-butyl acrylate, 2-ethylhexyl acrylate and the like are used. Further, the other monomer component mainly imparts cohesive force, and in particular, (meth) acrylic acid which forms a cross-linkage in the produced polymer is preferable and widely used.

[0006]

However, the water-dispersible acrylic pressure-sensitive adhesive obtained by the above-mentioned conventional method is still insufficient in the balance between the adhesive force and the cohesive force, and the water resistance is not sufficient.

Further, when a high solid content is obtained, the stability of the monomer emulsion (polymerization stability) and the stability of the resulting polymer emulsion (mechanical stability) are reduced depending on the type of emulsifier used. There are also things to do.

The present invention is intended to solve the above problems, and an object thereof is to obtain a polymer having good polymerization stability and mechanical stability, a low viscosity and a high solid content, and moreover, water resistance. An object of the present invention is to provide a water-dispersible acrylic pressure-sensitive adhesive and a pressure-sensitive adhesive tape or sheet which have excellent adhesiveness without deteriorating the properties.

[0009]

In order to achieve the above-mentioned object, in the present invention, an alkyl group (meth) acrylic acid alkyl ester having 4 to 14 carbon atoms is used as a main component, which is copolymerizable with the following. To produce a water-dispersible acrylic pressure-sensitive adhesive by emulsion-polymerizing a mixed monomer of at least one carboxyl group-containing monomer represented by the general formula (A) or (B) or (C) in an aqueous medium. It is a thing.

CH ₂ ═CHCOO— (CH ₂ —CH ₂ —COO) _n —H (A) (where, the average of n is 1 to 2) CH ₂ ═CHCOO— (C ₅ H ₁₀ —COO) _n —H (B) (where n averages ^{_{1~3) CH 2 = CR 1 COO}} -C 2 H 4 -OOC-R 2 -COOH (C) ( where, R ¹ is hydrogen or methyl, R ² is ethylene Group or arylene group)

Further, the present invention is to produce an adhesive tape or sheet using the above water-dispersible acrylic adhesive.

In the present invention, the (meth) acrylic acid ester whose alkyl group has 4 to 14 carbon atoms is n-
One or more monomers of butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl acrylate and lauryl methacrylate are preferable.

In the present invention, the expression (meth) acrylic means both acrylic and methacrylic, and
The expression (meth) acrylate means both acrylate and methacrylate.

These (meth) acrylic acid alkyl esters are used in an amount of 50 to 9 relative to the mixed monomer (all monomers).
It is preferably used in the range of 7% by weight. When the amount of this (meth) acrylic acid ester decreases, the adhesive force of the pressure-sensitive adhesive decreases, and when it increases, the cohesive force of the pressure-sensitive adhesive decreases.

The carboxyl group-containing monomer represented by the general formula (A) is an oligomer of acrylic acid,
Those having an average n of 1 to 2 are used. Examples of such a monomer include a product name M-5600 manufactured by Toagosei Co., Ltd., a product name Novamer β-CEA manufactured by Interez, which is called acrylic acid dimer.

The carboxyl group-containing monomer represented by the general formula (B) is obtained by ring-opening addition of ε-caprolactone to acrylic acid, and n having an average of 1 to 3 is used. As such a monomer, for example,
Toa Gosei Co., Ltd. brand name M-5300 ((epsilon) -caprolactone acrylate) etc. are mentioned.

The carboxyl group-containing monomer represented by the general formula (C) is 2-hydroxyethyl (meth) acrylate to which a dicarboxylic acid is added, and examples of the dicarboxylic acid include succinic acid or o-phthalic acid. Is used. As such a monomer, for example, trade name M-5500 (β-acryloxyethyl hydrogen succinate) manufactured by Toagosei Co., Ltd., trade name SA manufactured by Shin Nakamura Chemical Co., Ltd.
(Β-methacryloxyethyl hydrogen succinate) and trade name ACB-100 (β-acryloxyethyl hydrogen phthalate).

At least one or more of these carboxyl group-containing monomers represented by the general formulas (A), (B) and (C) are used. That is, they may be used alone or in combination of two or more.

When the amount of the carboxyl group-containing monomer decreases, the cohesive force of the pressure-sensitive adhesive decreases, and the creep resistance deteriorates. On the contrary, when the amount of the carboxyl-group-containing monomer increases, the cohesive force of the pressure-sensitive adhesive increases, and the adhesiveness at low temperature decreases. Therefore, it is preferably used in the range of 0.5 to 10% by weight based on the mixed monomer (all monomers).

In the present invention, another vinyl-based monomer which can be copolymerized may be used in combination, if necessary. Examples of such vinyl monomers include (meth) acrylic acid, itaconic acid, maleic acid, maleic anhydride, vinyl acetate, acrylonitrile, styrene, methyl (meth) acrylate, ethyl (meth) acrylate, and 2-hydroxyethyl (meth). ) One or more of acrylate, (meth) acrylamide, dimethylacrylamide, isopropylacrylamide, N-butoxymethylacrylamide, dimethylaminopropylacrylamide, dimethylaminoethylmethacrylate, N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine and the like. Monomers are used.

When such a vinyl-based monomer is used in combination, it is 30% by weight based on the mixed monomer (total monomer).
Used in the following range. When the amount of this vinyl-based monomer is large, the pressure-sensitive adhesive becomes hard and the adhesive strength is reduced.

Further, in order to improve the creep resistance of the pressure-sensitive adhesive, two or more copolymerizable double chains in the molecule of divinylbenzene, ethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, etc. A crosslinking-reactive polyfunctional monomer having a bond may be used in combination.

When such a polyfunctional monomer is used in combination, it is used in an amount of 1% by weight or less based on the mixed monomer (all monomers). If the amount of this polyfunctional monomer increases, the crosslink density will increase and the peel strength will decrease.

In the present invention, 100% by weight of the (meth) acrylic acid alkyl ester and the carboxyl group-containing monomer are mixed monomers (all monomers). When other vinyl-based monomers or polyfunctional monomers are used in combination, if necessary, these monomers are added to make a 100% by weight mixed monomer (all monomers). Then, this mixed monomer is emulsion-polymerized in an aqueous medium. In this case, a surfactant is generally used as the emulsifier.

As the surfactant, an anionic surfactant having a polyoxyethylene chain, such as polyoxyethylene alkyl ether sulfonate, polyoxyethylene alkyl ether sulfate, polyoxyethylene alkylphenyl ether sulfate, is polymerized. It is preferable in terms of stability and the like. In particular, those having a copolymerizable double bond in which a (meth) acryloyl group, a propenyl group, an allyl group or the like is added to such an anionic surfactant having a polyoxyethylene chain are more preferable.

Such an anionic surface active agent is added in an amount of 0.4 to 100 parts by weight based on 100 parts by weight of the mixed monomer (total monomer).
It is preferable to use in the range of 1.0 part by weight, and 0.5 to
More preferably, it is used in the range of 0.8 parts by weight. If the amount of this anionic surfactant decreases, the polymerization stability decreases, and conversely, if it increases, the water resistance of the pressure-sensitive adhesive decreases.

Further, such an anionic surfactant is used in combination with a nonionic surfactant having a polyoxyethylene chain such as polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene nonylphenyl ether. Are preferable in terms of mechanical stability and the like. In particular, those having a copolymerizable double bond obtained by adding a (meth) acryloyl group, a propenyl group, an allyl group to the nonionic surfactant having such a polyoxyethylene chain are more preferable.

In particular, when a surfactant having a copolymerizable double bond is used, the surfactant is copolymerized with the monomer during emulsion polymerization and is not separated from the particles of the copolymer, so that the surfactant as a whole is , A smaller amount of surfactant works well.

As described above, by reducing the amount of the surfactant, it is possible to prevent the particle size of the produced particles from becoming excessively fine, to prevent the viscosity from increasing, and also to prevent the water resistance from decreasing.

When the above nonionic surfactant is used in combination with the above anionic surfactant, the nonionic surfactant is 0.2 to 1.5 with respect to 100 parts by weight of the mixed monomer (total monomer). It is preferably used in the range of parts by weight, more preferably 0.2 to 1.0 parts by weight. However, the total amount of both surfactants should be 2 parts by weight or less. If the amount of this nonionic surfactant decreases, the mechanical stability decreases, and conversely, if it increases, the water resistance of the pressure-sensitive adhesive decreases.

For emulsion polymerization, a usual water-soluble polymerization initiator is used. Examples of such a polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate, water-soluble azo compounds such as azobiscyanovaleric acid, and redox-based compounds in which hydrogen peroxide and a reducing agent such as ferrous sulfate are combined. An initiator etc. are mentioned.

Such a polymerization initiator is used as the mixed monomer 1
Generally, 0.01 to 1.0 parts by weight, relative to 00 parts by weight,
It is preferably used in the range of 0.03 to 0.5 part by weight.

The emulsion polymerization is carried out by a known method. For example, a so-called batch charging method in which a polymerization initiator, a monomer, and an emulsifier are added to water, a so-called monomer dropping method in which a monomer is dropped in water containing a polymerization initiator and an emulsifier, and a monomer is emulsified in water containing an emulsifier. This is carried out by a so-called emulsion monomer dropping method in which this is dropped into water containing a polymerization initiator.

In this case, usually 1 to 10 at 50 to 90 ° C.
It is carried out with stirring over time. A chain transfer agent such as dodecyl mercaptan may be used to adjust the molecular weight of the copolymer.

In particular, as the emulsion polymerization, a so-called emulsion monomer dropping method capable of stably producing a water-dispersible acrylic pressure-sensitive adhesive having a high solid content is preferably adopted. The solid content concentration is
Generally, it is set relatively high at 50 to 75% by weight.

The water-dispersible acrylic pressure-sensitive adhesive thus obtained can be used as it is. Further, in order to improve the creep resistance, a cross-linking agent such as an aziridine type, an epoxy type or a blocked isocyanate type can be added and used.

Further, in order to improve the adhesiveness, a tackifier or an aqueous dispersion such as an ethylene-vinyl acetate copolymer can be added and used. In addition, these aqueous dispersions may be added to the mixed monomer and emulsion polymerization may be performed.

Other water-dispersible acrylic adhesives include
A pH adjusting agent, a viscosity adjusting agent, an emulsifying agent, a protective colloid, an antifoaming agent, a preservative, a pigment and the like may be added.

The water-dispersible acrylic pressure-sensitive adhesive is mainly composed of
Used in the production of adhesive tapes or sheets. That is, a pressure-sensitive adhesive tape or sheet is produced by coating the above water-dispersible acrylic pressure-sensitive adhesive on at least one surface of a substrate made of paper, nonwoven fabric, synthetic resin film such as polyester or polypropylene, metal foil, etc., and drying. To be done.

Further, the pressure-sensitive adhesive tape or sheet is formed by applying the above water-dispersible acrylic pressure-sensitive adhesive to one surface of the release-treated film and drying it to form a pressure-sensitive adhesive layer,
It can also be produced by transferring this pressure-sensitive adhesive layer onto at least one surface of a substrate made of paper, non-woven fabric, synthetic resin film such as polyester or polypropylene, metal foil or the like.

[0041]

[Function] The (meth) acrylic acid alkyl ester component is
It mainly gives adhesive strength. When this is combined with at least one carboxyl group-containing monomer represented by the general formula (A) or (B) or (C) and copolymerized, cohesive force is mainly imparted to the conventional acrylic acid. As a result, it is possible to obtain a well-balanced adhesive performance and to improve water resistance, as compared with those obtained by combining and copolymerizing.

The reason is presumed to be as follows. That is, when the conventional acrylic acid is used in combination for copolymerization, most of the acrylic acid is present in water because the acrylic acid is highly water-soluble, the copolymerization cannot be carried out according to the charging ratio, and the residual monomer remains at the final stage of the copolymerization. The ratio of acrylic acid in the inside increases, and a highly hydrophilic polymer is produced.

On the other hand, when at least one carboxyl group-containing monomer represented by the above general formula (A), (B) or (C) is combined and copolymerized, the specific carboxyl group-containing monomer is water-soluble. Since the property is low, the above phenomenon does not occur, copolymerization close to the charging ratio is possible, and a highly hydrophilic polymer is not generated.
Therefore, it is presumed that a well-balanced adhesive performance is obtained and the water resistance is also improved.

[0044]

EXAMPLES Examples and comparative examples of the present invention will be shown below. Example 1 50 parts by weight of ion-exchanged water in which 0.1 part by weight of ammonium persulfate was dissolved was placed in a reactor equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen inlet tube, and the mixture was heated to 70 in a nitrogen atmosphere.
Warmed to ° C.

As a monomer composition, 20 parts by weight of 2-ethylhexyl acrylate and 74 n-butyl acrylate are used.
6 parts by weight of acrylic acid dimer (average of n is 1.4) (M-5600: manufactured by Toagosei Co., Ltd.) was used as the monomer of the general formula (A).

As an anionic surfactant, propoxy group-added polyoxyethylene nonylphenyl ether ammonium sulfate (ethylene oxide addition mole number 10)
(Aqualon HS-10: manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) 0.6 part by weight was used, and as a nonionic surfactant, a propenyl group-added polyoxyethylene nonylphenyl ether (ethylene oxide addition mole number 20) (Aqualon RN-20 :
Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 part by weight was used.

100 parts by weight of the above monomer composition, 0.6 parts by weight of anionic surfactant, 0.3 parts by weight of nonionic surfactant, and 30 parts by weight of deionized water are mixed and stirred to prepare an emulsified monomer. , Charged to the dropping funnel.

This emulsion monomer was added dropwise to the above ion-exchanged water in which ammonium persulfate was dissolved for 3 hours to carry out emulsion polymerization. During the emulsion polymerization, the temperature in the reactor is kept at 70
Hold at ℃.

After that, the dropping funnel was washed with 1 part by weight of ion-exchanged water and added dropwise, and the mixture was kept at 70 ° C. for 1 hour to carry out emulsion polymerization. Then, the temperature was raised to 90 ° C. and the mixture was kept and aged for 1 hour. The polymerization conversion rate was 99% or more.

The emulsion polymerization liquid was cooled to 30 ° C. or lower and neutralized with 25% by weight aqueous ammonia. In addition to this, a urethane thickener (Adecanol UH-438: manufactured by Asahi Denka Co., Ltd.)
0.4 parts by weight was mixed and stirred and then filtered to produce a water-dispersed acrylic pressure-sensitive adhesive.

This adhesive has a PH of 7.8 and a solid content of 5
The viscosity was 5.3% by weight and the viscosity was 12000 cps. Further, when the polymerization stability and the mechanical stability were evaluated, the polymerization stability was 0.01% by weight or less, and the mechanical stability was 0.01% by weight.

The polymerization stability is determined by filtering the dispersion, which is neutralized after emulsion polymerization and mixed with a thickener, with a 200-mesh stainless steel wire net, and the coarse particles left on the wire net are in proportion to the total solid content. (% By weight).

With respect to the mechanical stability, 50 g of a dispersion obtained by emulsion polymerization, neutralization, mixing with a thickening agent, and filtration, and 1,000 r under a pressure of 10 kg / cm ² were conducted by a Marlon type mechanical stability tester.
After rotating at pm for 5 minutes, the coarse particles aggregated in the test container were shown as a ratio (% by weight) to the total solid content.

Further, the above water-dispersible acrylic pressure-sensitive adhesive was applied onto one surface of a release-treated polyester film (PET) so as to have a paste thickness of 60 μm and dried, and the basis weight was 14 g / m ² The double-sided pressure-sensitive adhesive tape (without addition of a cross-linking agent) was produced by transferring the double-sided adhesive tape to both sides of the cellulosic non-woven fabric.

Regarding the above double-sided adhesive tape, JIS
According to Z 1528, the adhesive force (g / 20 mm width) (180 ° peeling, 20 ° C. × 65% RH) to a stainless steel plate and a polypropylene plate was measured.

Regarding the above double-sided adhesive tape, J
Holding power (deviation length mm) according to IS Z 1528
(Attached area 20 mm × 20 mm, 1 kg load × 1 hour, 4
0 ° C. × 65% RH and 40 ° C. × 90% RH) were measured. In particular, water resistance can be evaluated under the measurement conditions of 90% RH.

In addition, in the measurement of the holding force, if the product dropped within 1 hour, the time (minute) and the drop are entered in the table.
Also, if there is no deviation, it is entered as no deviation.
The above results are collectively shown in Table 1 together with the emulsion polymerization composition.

Example 2 In Example 1, the monomer composition was changed to 50 parts by weight of 2-ethylhexyl acrylate and 4 parts of n-butyl acrylate.
4 parts by weight, 3 parts by weight of methyl methacrylate, acrylic acid dimer (average of n is 1.0) (Novamer β-CEA: Inte) as the monomer of the general formula (A).
(manufactured by Rez) changed to 3 parts by weight.

Further, the anionic surfactant was changed to 0.6 part by weight of propenyl group-added polyoxyethylene nonylphenyl ether ammonium sulfate (ethylene oxide addition mole number 40) (Aqualon RN-40: manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.). did. In addition, a nonionic surfactant was used as a propenyl group-added polyoxyethylene nonylphenyl ether (ethylene oxide addition mole number 20) (Aqualon HS-20:
(Manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) 0.4 parts by weight

Further, n-dodecyl mercaptan 0.03
Parts by weight were used. Further, the dropping time of the emulsified monomer was changed to 5 hours. Other than that was performed like Example 1.
The results are collectively shown in Table 1 together with the emulsion polymerization composition.

Example 3 In Example 1, the monomer composition was changed to 85 parts by weight of 2-ethylhexyl methacrylate and 1 part of methyl methacrylate.
0 parts by weight, as the monomer of the general formula (A), acrylic acid dimer (average of n is 1.0) (Novamer
β-CEA: manufactured by Interez) was changed to 5 parts by weight.

Further, the anionic surfactant was changed to 0.9 parts by weight of allyl group-added polyoxyethylene nonylphenyl ether ammonium sulfate (ethylene oxide addition mole number 10) (Adecaria Soap SE-10N: manufactured by Asahi Denka Co., Ltd.). did. Further, a nonionic surfactant was used as an allyl group-added polyoxyethylene nonylphenyl ether (ethylene oxide addition mole number 10) (ADEKA REASOAP NE-10:
(Asahi Denka Co., Ltd.) 0.3 parts by weight.

Further, n-dodecyl mercaptan 0.05
Parts by weight were used. Other than that was performed like Example 1. The results are summarized together with the emulsion polymerization composition in Table 1.
Shown in.

Further, a cross-linking agent (DZ-22E: manufactured by Nippon Shokubai Co., Ltd.) composed of an aziridine compound was added to the water-dispersible acrylic pressure-sensitive adhesive obtained in this example, and the gel fraction of the pressure-sensitive adhesive layer (dissolved in tetrahydrofuran) was used. The amount of insoluble matter when added was about 60% by weight, and a double-sided pressure-sensitive adhesive tape (with addition of a cross-linking agent) was prepared in the same manner, and the pressure-sensitive adhesive force and the holding force were measured. The results are also shown in Table 1.

Example 4 In Example 1, the monomer composition was changed to 40 parts by weight of 2-ethylhexyl acrylate and 4 parts of n-butyl acrylate.
5 parts by weight, 0.5 parts by weight of methacrylamide, and as a monomer of the general formula (A), acrylic acid dimer (average of n is 1.0) (Novamer β-CEA: Inte.
It was changed to 4.5 parts by weight, and 10 parts by weight of a hydrogenated rosin-based tackifier (Foral 105: manufactured by Rika Hercules Co., Ltd.) was dissolved therein. Other than that was performed like Example 1. The results are collectively shown in Table 1 together with the emulsion polymerization composition.

Example 5 In Example 1, instead of 6 parts by weight of acrylic acid dimer (average of n is 1.4) (M-5600: manufactured by Toagosei Co., Ltd.), as the monomer of the general formula (B), The amount was changed to 6 parts by weight of caprolactone acrylate (average of n was 2) (M-5300: manufactured by Toagosei Co., Ltd.). Other than that was performed like Example 1. The results are collectively shown in Table 2 together with the emulsion polymerization composition. Example 6 In Example 2, acrylic acid dimer (average of n is 1.0) (Novamer β-CEA: Intere
3 parts by weight instead of 3 parts by weight of Z Co.) was changed to 3 parts by weight of caprolactone acrylate (average of n is 2) (M-5300: manufactured by Toagosei Co., Ltd.) as the monomer of the general formula (B). Other than that was performed like Example 2. The results are collectively shown in Table 2 together with the emulsion polymerization composition.

Example 7 In Example 3, acrylic acid dimer (average of n was 1.0) (Novamer β-CEA: Intere)
5 parts by weight instead of 5 parts by weight of Z company) was changed to 5 parts by weight of caprolactone acrylate (average of n is 2) (M-5300: manufactured by Toagosei Co., Ltd.) as the monomer of the general formula (B). Other than that was performed like Example 3. The results are collectively shown in Table 2 together with the emulsion polymerization composition.

Further, a cross-linking agent (DZ-22E: manufactured by Nippon Shokubai Co., Ltd.) composed of an aziridine compound was added to the water-dispersible acrylic pressure-sensitive adhesive obtained in this example, and the gel fraction of the pressure-sensitive adhesive layer (dissolved in tetrahydrofuran). The amount of insoluble matter when added was about 60% by weight, and a double-sided pressure-sensitive adhesive tape (with addition of a cross-linking agent) was prepared in the same manner, and the pressure-sensitive adhesive force and the holding force were measured. The results are also shown in Table 2.

Example 8 In Example 4, acrylic acid dimer (average of n is 1.0) (Novamer β-CEA: Intere)
(manufactured by z Co., Ltd.) 4.5 parts by weight was changed to 4.5 parts by weight of the monomer of the general formula (B) as caprolactone acrylate (average of n is 2) (M-5300: manufactured by Toagosei Co., Ltd.). . Other than that was performed like Example 4. The results are collectively shown in Table 2 together with the emulsion polymerization composition.

Example 9 In Example 1, instead of 6 parts by weight of acrylic acid dimer (average of n is 1.4) (M-5600: manufactured by Toagosei Co., Ltd.), as the monomer of the general formula (C), β-acryloyloxyethyl hydrogen succinate (M-5
500: manufactured by Toagosei Co., Ltd.) 6 parts by weight.

Otherwise, the same procedure as in Example 1 was carried out. The results are collectively shown in Table 3 together with the emulsion polymerization composition. Example 10 In Example 2, acrylic acid dimer (average of n is 1.0) (Novamer β-CEA: Intere
z) (manufactured by Z Co.) and 5 parts by weight of β-methacryloxyethyl hydrogen succinate (SA: manufactured by Shin-Nakamura Chemical Co., Ltd.) as the monomer of the general formula (C). Other than that was performed like Example 2. The results are collectively shown in Table 3 together with the emulsion polymerization composition.

Example 11 In Example 3, acrylic acid dimer (average of n is 1.0) (Novamer β-CEA: Intere)
(manufactured by Z Co., Ltd.), and 7 parts by weight of β-acryloxyethyl hydrogen phthalate (ACB-100: manufactured by Shin-Nakamura Chemical Co., Ltd.) as the monomer of the general formula (C). Other than that was performed like Example 3. The results are collectively shown in Table 3 together with the emulsion polymerization composition.

Example 12 In Example 4, acrylic acid dimer (average of n is 1.0) (Novamer β-CEA: Intere)
(manufactured by Z company) instead of 4.5 parts by weight, β-acroyloxyethyl hydrogen phthalate (ACB-100: manufactured by Shin-Nakamura Chemical Co., Ltd.) as a monomer of the general formula (C).
Changed to 5 parts by weight. Other than that was performed like Example 4. The results are collectively shown in Table 3 together with the emulsion polymerization composition.

Comparative Example 1 In Example 1, the monomer composition was changed to 20 parts by weight of 2-ethylhexyl methacrylate, 77 parts by weight of n-butyl acrylate and 3 parts by weight of acrylic acid. Also,
0.05 part by weight of n-dodecyl mercaptan was used. Other than that was performed like Example 1. The results are collectively shown in Table 4 together with the emulsion polymerization composition.

[0075]

[Table 1]

[0076]

[Table 2]

[0077]

[Table 3]

[0078]

[Table 4]

[0079]

As described above, the water-dispersible acrylic pressure-sensitive adhesive of the present invention has good polymerization stability and mechanical stability, has a low viscosity and a high solid content, and does not decrease the water resistance. Excellent adhesion performance.

Therefore, when an adhesive tape or sheet is produced using such a water-dispersible acrylic adhesive, it can be produced efficiently. The resulting adhesive tape or sheet has good water resistance and excellent adhesiveness, and can be suitably used for packaging, office work, electrical insulation, medical use, display, and a wide range of other purposes.

Claims (3)

[Claims] 1. A compound represented by the following general formula (A), (B) or (C), which comprises a (meth) acrylic acid alkyl ester having an alkyl group having 4 to 14 carbon atoms as a main component and is copolymerizable therewith.
A water-dispersible acrylic pressure-sensitive adhesive obtained by emulsion-polymerizing a mixed monomer of at least one kind of carboxyl group-containing monomer represented by _{CH 2 = CHCOO- (CH 2 -CH} 2 -COO) n -H (A) ( where n averages _{1~2) CH 2 = CHCOO- (C} 5 H 10 ─COO) n -H (B) (However, the average of n is ^{_{1~3) CH 2 = CR 1 COO}} -C 2 H 4 -OOC-R 2 -COOH (C) ( where, R ¹ is hydrogen or methyl, R ² is an ethylene group or an arylene Basis) 2. A (meth) acrylic acid alkyl ester having an alkyl group having 4 to 14 carbon atoms and at least one of the following general formulas (A) or (B) or (C) copolymerizable therewith. A water-dispersible acrylic pressure-sensitive adhesive obtained by emulsion-polymerizing a mixed monomer of one kind of a carboxyl group-containing monomer and a surfactant having a polymerizable double bond as an emulsifier in an aqueous medium. _{CH 2 = CHCOO- (CH 2 -CH} 2 -COO) n -H (A) ( where n averages _{1~2) CH 2 = CHCOO- (C} 5 H 10 ─COO) n -H (B) (However, the average of n is ^{_{1~3) CH 2 = CR 1 COO}} -C 2 H 4 -OOC-R 2 -COOH (C) ( where, R ¹ is hydrogen or methyl, R ² is an ethylene group or an arylene Basis) 3. A pressure-sensitive adhesive tape or sheet using the water-dispersible acrylic pressure-sensitive adhesive according to claim 1.