JPH10168420A - Pressure-sensitive adhesive, pressure-sensitive sheet or the like coated therewith and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive which can dispense with process paper in its production step, can be directly applied to a support and may contain a water-soluble substance, to provide a pressure-sensitive adhesive sheet or the like coated therewith and to provide a method for producing the same. SOLUTION: A pressure-sensitive adhesive based on an acrylic copolymer which has carboxyl groups in the molecule and in which 1/5 to 1/1 of the carboxyl groups are neutralized is obtained. A pressure-sensitive adhesive sheet or like can be obtained by coating at least either surface of a support with this adhesive. An organic solution of the adhesive is mixed with neutralized water to form a thickened water-containing pressure-sensitive adhesive solution, and this solution is applied. This is effective for direct transfer to a porous support 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pressure-sensitive adhesive obtained by mixing a water-soluble substance with a hydrophobic pressure-sensitive adhesive, pressure-sensitive adhesive sheets using the same, and a method for producing the same.

[0002]

2. Description of the Related Art In a pressure-sensitive adhesive sheet, a pressure-sensitive adhesive layer is usually used.
It is formed by mixing with a solvent such as an organic solvent to form a pressure-sensitive adhesive liquid, and applying it on a support. When a low-viscosity solvent-based pressure-sensitive adhesive liquid is applied directly on a porous support, the pressure-sensitive adhesive liquid is Easily slips through the back of the body. For this reason, when the adhesive liquid adheres to each part of the coating machine, or when the manufactured adhesive sheet is rolled, the adhesive sheet adheres to the back side, and the adhesive sheet adheres to the back, making it difficult to rewind. There are a number of problems, such as the application of a filler and a release agent on the back surface due to the adhesive that has slipped through or the show-through.

Therefore, when an adhesive layer is formed on a porous support using an organic solvent-based adhesive liquid, it is often difficult to directly apply the adhesive liquid on the support. In many cases, the liquid was once applied on a release paper to form an adhesive layer, which was dried and then bonded to a porous support.

Further, the main component of the pressure-sensitive adhesive such as an acrylic copolymer is often soluble in an organic solvent, and an organic solvent is frequently used for preparing a pressure-sensitive adhesive solution. It was difficult to mix small water-soluble substances.

[0005]

In the above-mentioned manufacturing method, even if release paper is not required as a product, release paper is required in the manufacturing process, a large amount of material is wasted, and a device for bonding to a support is required in terms of equipment. Is also required, and the cost increases. Also,
It is very difficult to mix a water-soluble substance in an organic solvent-based pressure-sensitive adhesive, and materials that can be mixed in pressure-sensitive adhesive sheets have been limited.

The inventors of the present invention have found that, in an organic solvent solution of a pressure-sensitive adhesive containing an acrylic copolymer having a carboxyl group in the molecule as a main component, a part or all of the carboxyl group is neutralized to thereby obtain a tacky adhesive. Water can be mixed in the organic solvent solution, the viscosity is significantly increased from the initial organic solvent solution, and it is possible to obtain a water-containing adhesive liquid in which water is stably dispersed in the adhesive liquid. They found that they solved the above problem.

An object of the present invention is to provide an organic solvent-based pressure-sensitive adhesive capable of stably blending a water-soluble substance, and to directly apply a pressure-sensitive adhesive liquid to a porous support, to the back of the pressure-sensitive adhesive liquid support. An object of the present invention is to provide a method for producing a pressure-sensitive adhesive sheet which can reduce the strike-through of the pressure-sensitive adhesive sheet and can produce the pressure-sensitive adhesive sheet without a release paper.

[0008]

SUMMARY OF THE INVENTION The present invention has a carboxyl group in the molecule, and contains 1/5 to 1/1 of the carboxyl group.
A pressure-sensitive adhesive containing an acrylic copolymer as a main component, pressure-sensitive adhesive sheets having a layer composed of the pressure-sensitive adhesive on one or both sides of a support, and an acrylic copolymer having a carboxyl group in the molecule To an organic solvent solution of a pressure-sensitive adhesive containing as a main component, 1/5 to 1/1 of the carboxyl group is neutralized and mixed with water to obtain a water-containing pressure-sensitive adhesive liquid in which water is stably dispersed. An object of the present invention is to provide a method for producing a pressure-sensitive adhesive sheet, characterized in that the water-containing pressure-sensitive adhesive liquid is directly applied to one or both surfaces of a support and dried to obtain a pressure-sensitive adhesive layer.

According to the present invention, when preparing a hydrous adhesive liquid,
By dissolving the water-soluble substance in the water to be added, the hydrophobic pressure-sensitive adhesive and the water-soluble substance can be easily mixed, and the choice of materials used for the pressure-sensitive adhesive can be greatly expanded.

In addition, the highly viscous water-containing pressure-sensitive adhesive liquid obtained according to the present invention has little adhesive strike-through on the back surface of the support even when directly applied to a porous support, and can be used without a release paper. Production of sheets is possible. In addition, since there is no strikethrough of the adhesive, it is easy to apply a filler, a backsize agent or a release agent on the opposite surface to which the hydrated adhesive is applied,
Even if it is made into a roll, no problem occurs in use.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The acrylic copolymer having a carboxyl group in the molecule used in the present invention refers to a monomer having a carboxyl group such as (meth) acrylic acid, itaconic acid, maleic acid and maleic anhydride. (Meth) acrylate monomers such as isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and vinyl copolymerizable therewith. It is a polymer obtained by copolymerizing a system monomer, and is appropriately selected as needed.

The acrylic copolymer is insoluble in water and is used as an organic solvent solution. The copolymer concentration in the organic solvent solution is preferably 10 to 50% by weight. 1
If the amount is less than 0% by weight, it is not easy to obtain a high-viscosity water-containing pressure-sensitive adhesive solution, which is disadvantageous in terms of cost. If the amount exceeds 50% by weight, the viscosity of the copolymer solution becomes extremely high, which makes handling difficult. Become.

Further, 1/5 to 1/1 of the carboxyl group of the above copolymer is neutralized. The substances used for neutralization are:
There is no particular limitation, and examples thereof include ammonia, amines such as triethanolamine, and hydroxides of monovalent alkali metals such as sodium hydroxide and potassium hydroxide. If the carboxyl group to be neutralized is less than 1/5, a stable high-viscosity water-containing pressure-sensitive adhesive liquid cannot be obtained, and even if a neutralizing agent in an amount exceeding 1/1 is added, the viscosity is significantly higher than that of a 1/1 neutralized product. I can't get up.

When the carboxyl group is neutralized with the above neutralizing agent, even if water is mixed, the mixture is stably present in the pressure-sensitive adhesive liquid without being phase-separated for a long time, and a water-containing pressure-sensitive adhesive liquid is obtained.
The amount of water to be mixed is appropriately adjusted according to the target viscosity or the amount of the water-soluble substance to be mixed and the porosity of the support. The amount of water to be blended is preferably 1 to 50% by weight based on 100% by weight of the aqueous pressure-sensitive adhesive liquid. If it is less than 1% by weight, no significant increase in viscosity is observed, and if it exceeds 50% by weight, the pressure-sensitive adhesive liquid tends to gel.

The pressure-sensitive adhesive of the present invention can contain a water-soluble substance because water is stably contained in the pressure-sensitive adhesive liquid before the formation of the pressure-sensitive adhesive layer.

Examples of the water-soluble substance include a water-soluble polymer such as polyvinyl alcohol, a water-soluble crosslinking agent, a water-soluble drug, a glycoprotein and the like. In particular, the water-soluble polymer is preferably blended in an amount of 0.1 to 100 parts by weight based on 100 parts by weight of the acrylic copolymer.

These water-soluble substances are blended by a conventional method such as dissolving a water-soluble substance in water to be added when preparing a water-containing pressure-sensitive adhesive liquid.

The pressure-sensitive adhesive of the present invention and the pressure-sensitive adhesive liquid used in the present invention include a plasticizer, a tackifier, an antioxidant, a cross-linking agent for an acrylic copolymer, and A filler or the like may be added.

The pressure-sensitive adhesive sheets and the like can be obtained by forming a pressure-sensitive adhesive layer using the pressure-sensitive adhesive of the present invention. A pressure-sensitive adhesive sheet can be produced by forming a high-viscosity water-containing pressure-sensitive adhesive liquid by the above-described method, directly applying the water-containing pressure-sensitive adhesive liquid to one or both surfaces of the support, and drying to obtain a pressure-sensitive adhesive layer.

Further, the above-mentioned hydrated pressure-sensitive adhesive liquid may be coated on a release paper and dried to form a pressure-sensitive adhesive layer, which may be adhered to various substrates to produce pressure-sensitive adhesive sheets.

The support used for the pressure-sensitive adhesive sheet of the present invention is:
Not particularly limited, plastic film, paper, non-woven fabric,
A foam, a metal foil, or the like can be used.

Since the water-containing pressure-sensitive adhesive liquid obtained from the pressure-sensitive adhesive of the present invention can be easily increased in viscosity, it can be applied directly to one surface of a porous support such as a non-woven fabric, or can be applied to the back of the support. , The uniform application of the filler and the release agent is facilitated, and the desired quality without adhesion or the like can be obtained even in the case of a roll-shaped product.

In the pressure-sensitive adhesive of the present invention, strike-through of the pressure-sensitive adhesive to the back surface is reduced by appropriately adjusting the viscosity of the water-containing pressure-sensitive adhesive solution according to the degree of porosity such as the pore diameter and porosity of the support. be able to.

The pressure-sensitive adhesive sheets of the present invention include those having various shapes such as a sheet shape and a tape shape.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. In the following, parts and% indicate parts by weight and% by weight, respectively.

[0026]

【Example】

Example 1 Under a nitrogen gas atmosphere, acrylic acid 5 parts, acrylic acid 2-
To 100 parts of an acrylic copolymer pressure-sensitive adhesive solution having a copolymer concentration of 30% obtained by copolymerizing 95 parts of ethylhexyl ester with ethyl acetate as a solvent, 25% aqueous ammonia was added to an acrylic copolymer pressure-sensitive adhesive solution. Water was added in such an amount as to neutralize 100% of the carboxyl groups in the water-containing pressure-sensitive adhesive liquid so as to be 15% of the pressure-sensitive adhesive liquid, and mixed and stirred to obtain a water-containing pressure-sensitive adhesive liquid in which water was stably dispersed.

The viscosity of the acryl-based copolymer pressure-sensitive adhesive solution, the water-containing pressure-sensitive adhesive solution after the addition of water and ammonia was measured using a B
Using an H-type rotational viscometer, the rotational speed of the rotor is 10 rpm.
m, the solution temperature was 30 ° C., and as a result, the viscosity of the acrylic copolymer pressure-sensitive adhesive solution was 14 Pa · s, while the viscosity of the water-containing pressure-sensitive adhesive liquid was 31.6 Pa · s, and the viscosity was significantly increased.

Next, a non-woven fabric (weighing 35 g / m ² , trade name NS-3500, manufactured by Nippon Paper Industry Co., Ltd.) is applied to the water-containing pressure-sensitive adhesive liquid by an applicator so that the pressure-sensitive adhesive thickness after drying is 50 μm. Was applied directly. Immediately after the application, the penetration of the pressure-sensitive adhesive to the back surface of the nonwoven fabric was at a level that caused almost no problem.

Example 2 The aqueous pressure-sensitive adhesive solution obtained in Example 1 was applied to a nonwoven fabric in the same manner as in Example 1, and an acrylic ester-based emulsion was immediately applied as a filler on the back surface. (Trade name: VONCOAT R-3360, manufactured by Dainippon Ink and Chemicals, Inc.) was applied after drying to a weight of about 10 g / m ² , and dried at 100 ° C. for 5 minutes. In the state after drying, strike-through of the pressure-sensitive adhesive was extremely small, and a sealing agent could be applied without any problem.

Example 3 The same acrylic copolymer pressure-sensitive adhesive solution 100 as in Example 1
To a part of the adhesive solution, 24 parts of sorbitan trioleate was added, and triethanolamine was used as a neutralizing agent in an amount to neutralize 100% of the carboxyl groups in the adhesive solution.
Triglycidyl isocyanurate (TEPIC-G, manufactured by Nissan Chemical Co., Ltd.) as a cross-linking agent for the acrylic copolymer
Was added so that water became 12% of the water-containing pressure-sensitive adhesive liquid, and mixed and stirred to obtain a water-containing pressure-sensitive adhesive liquid in which water was stably dispersed.

When the viscosity was measured in the same manner as in Example 1, the viscosity of the pressure-sensitive adhesive solution was 7 Pa · s, and the viscosity of the water-containing pressure-sensitive adhesive solution after addition of water and ammonia was 31.6 Pa · s.

Next, a water-containing pressure-sensitive adhesive was applied to the nonwoven fabric in the same manner as in Example 1. Immediately after the application, the penetration of the pressure-sensitive adhesive to the back surface of the nonwoven fabric was at a level that caused almost no problem.

Example 4 Acrylic acid 5 parts, acrylic acid 2-
10.8 parts of sorbitan trioleate and 25% aqueous ammonia were added to 100 parts of an acrylic copolymer adhesive solution having a copolymer concentration of 26.9% obtained by copolymerizing 95 parts of ethylhexyl ester using ethyl acetate as a solvent. Is added in such an amount as to neutralize 1/5 of the carboxyl groups in the pressure-sensitive adhesive solution so that the water becomes 15.3% of the water-containing pressure-sensitive adhesive solution, and the mixture is stirred and mixed to stably disperse the water. An adhesive liquid was obtained.

When the viscosity was measured by the same method as in Example 1, the viscosity of the water-containing pressure-sensitive adhesive liquid after addition of ammonia was 1
It was 6 Pa · s.

Next, a water-containing pressure-sensitive adhesive liquid was applied to the nonwoven fabric in the same manner as in Example 1. Immediately after the application, the penetration of the pressure-sensitive adhesive to the back surface of the nonwoven fabric was at a level that caused almost no problem.

Example 5 A copolymer obtained by copolymerizing 5 parts of acrylic acid, 5 parts of isobutyl acrylate, and 95 parts of 2-ethylhexyl acrylate in a nitrogen gas atmosphere using toluene as a solvent has a concentration of 39%. Acrylic copolymer solution 100
4.9 parts of isopropyl alcohol was added to the solution, an aqueous solution of potassium hydroxide as a neutralizing agent was added in an amount to neutralize 100% of the carboxyl groups in the solution, and water was further added. It was added so as to be 2% of the water-containing pressure-sensitive adhesive liquid, mixed and stirred to obtain a water-containing pressure-sensitive adhesive liquid in which water was stably dispersed.

When the viscosity was measured in the same manner as in Example 1, the viscosity of the pressure-sensitive adhesive solution was 8.2 Pa · s.
The viscosity of the water-containing pressure-sensitive adhesive liquid was as high as 68.3 Pa · s. Next, a water-containing pressure-sensitive adhesive liquid was applied to the nonwoven fabric in the same manner as in Example 1. Immediately after the application, the penetration of the pressure-sensitive adhesive to the back surface of the nonwoven fabric was at a level that caused almost no problem.

Example 6 A water-containing pressure-sensitive adhesive liquid was prepared in the same manner as in Example 5, except that water was added so that the amount of water in the water-containing pressure-sensitive adhesive liquid was 20%.

When the viscosity was measured by the same method as in Example 1, the viscosity was as high as 330 Pa · s.

Next, in the same manner as in Example 1, a hydrated pressure-sensitive adhesive liquid was weighed at 25 g / m ^{2 to form} a nonwoven fabric (trade name: Axter G
(2015-8P, manufactured by Toray Industries, Inc.). Immediately after the application, the penetration of the pressure-sensitive adhesive to the back surface of the nonwoven fabric was at a level with no problem, and direct application to a low-density porous support was possible.

Example 7 A copolymer obtained by copolymerizing 5 parts of acrylic acid, 5 parts of isobutyl acrylate, and 95 parts of 2-ethylhexyl acrylate in a nitrogen gas atmosphere using toluene as a solvent has a concentration of 21%. Acrylic copolymer solution 100
Then, 5 parts of isopropyl alcohol was added to the mixture to obtain an adhesive solution having a copolymer concentration of 20%. An aqueous solution of potassium hydroxide is added to the adhesive solution to prepare a 10% of carboxyl groups in the adhesive solution.
An aqueous solution of sodium carboxymethylcellulose (sodium carboxymethylcellulose, cellogen HP-6HS9, degree of etherification 0.8-0.9, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was further added to the aqueous pressure-sensitive adhesive liquid. 0.285% (0.327 parts with respect to 100 parts of acrylic copolymer) in water and 39.7% of water in the water-containing pressure-sensitive adhesive, followed by stirring and mixing, and water and carboxymethyl cellulose. A water-containing pressure-sensitive adhesive liquid in which sodium was stably dispersed was obtained.

When the viscosity was measured in the same manner as in Example 1, the viscosity of the pressure-sensitive adhesive solution was 0.8 Pa · s.
The viscosity of the water-containing pressure-sensitive adhesive liquid was 94 Pa · s.

Next, a water-containing pressure-sensitive adhesive liquid was applied to the nonwoven fabric in the same manner as in Example 1. Immediately after the application, the penetration of the pressure-sensitive adhesive to the back surface of the nonwoven fabric was at a level that caused almost no problem.

Example 8 The same acrylic copolymer pressure-sensitive adhesive solution 100 as in Example 1
To this part, an aqueous solution of potassium hydroxide is added in an amount to neutralize 100% of the carboxyl groups in the adhesive solution. further,
A 20% aqueous solution of polyvinyl alcohol (trade name: PVA210, saponification degree: 88 mol%, manufactured by Kuraray Co., Ltd.) is used by adding 1 part of polyvinyl alcohol to 100 parts of the acrylic copolymer.
1.5 parts by weight, and water was added to the water-containing pressure-sensitive adhesive liquid.
% And stirred and mixed to obtain a water-containing pressure-sensitive adhesive liquid in which water and polyvinyl alcohol are stably dispersed.

When the viscosity was measured in the same manner as in Example 1, the viscosity of the water-containing pressure-sensitive adhesive liquid was 33 Pa · s.

Next, a water-containing pressure-sensitive adhesive liquid was applied to the nonwoven fabric in the same manner as in Example 1. Immediately after the application, the penetration of the pressure-sensitive adhesive to the back surface of the nonwoven fabric was at a level with almost no problem, and a pressure-sensitive adhesive tape in which water-soluble polyvinyl alcohol was uniformly dispersed in the hydrophobic acrylic copolymer pressure-sensitive adhesive was obtained.

Example 9 A copolymer obtained by copolymerizing 5 parts of acrylic acid, 5 parts of isobutyl acrylate and 95 parts of 2-ethylhexyl acrylate with toluene as a solvent was dried under a nitrogen gas atmosphere. Isopropyl alcohol 1 was added to 90 parts of a 50% acrylic copolymer solution obtained by re-dissolving.
By adding 0 parts, an adhesive solution having a copolymer concentration of 45% was obtained.
To this pressure-sensitive adhesive solution, an aqueous solution of sodium hydroxide is added in an amount to neutralize 100% of the carboxyl groups in the pressure-sensitive adhesive solution, and water is further added to 2.5% of the water-containing pressure-sensitive adhesive solution, followed by stirring. The mixture was mixed to obtain a water-containing pressure-sensitive adhesive liquid.

When the viscosity was measured in the same manner as in Example 1, the viscosity of the pressure-sensitive adhesive solution was 38.9 Pa · s, while the viscosity of the water-containing pressure-sensitive adhesive solution was 71.2 Pa · s.
Next, a water-containing pressure-sensitive adhesive liquid was applied to the nonwoven fabric in the same manner as in Example 1. Immediately after the application, the penetration of the pressure-sensitive adhesive to the back surface of the nonwoven fabric was at a level that caused almost no problem.

Example 10 A copolymer obtained by copolymerizing 5 parts of acrylic acid, 5 parts of isobutyl acrylate, and 95 parts of 2-ethylhexyl acrylate in a nitrogen gas atmosphere using toluene as a solvent has a concentration of 28%. 10 parts of isopropyl alcohol was added to 60 parts of the acrylic copolymer solution of Example 1 to obtain an adhesive solution having a copolymer concentration of 24%. To this pressure-sensitive adhesive solution, an aqueous solution of sodium hydroxide was added in an amount to neutralize 100% of the carboxyl groups in the pressure-sensitive adhesive solution. Further, polyvinyl alcohol (trade name: PVA103, saponification degree: 98.5 mol%, manufactured by Kuraray Co., Ltd.) ) Is added to 100 parts of the acrylic copolymer so that the polyvinyl alcohol becomes the same amount, and the mixture is stirred and mixed.
A 3.8% aqueous pressure-sensitive adhesive liquid was obtained.

When the viscosity was measured in the same manner as in Example 1, the viscosity of the pressure-sensitive adhesive solution was 1.1 Pa · s.
The viscosity of the water-containing pressure-sensitive adhesive liquid was 200 Pa · s.

Next, a water-containing pressure-sensitive adhesive liquid was applied to the nonwoven fabric in the same manner as in Example 1. Immediately after the application, the penetration of the pressure-sensitive adhesive to the back surface of the nonwoven fabric was at a level that caused almost no problem.

Comparative Example 1 The same acrylic copolymer pressure-sensitive adhesive solution as in Example 1 was applied to a nonwoven fabric in the same manner as in Example 1. Immediately after the application, the pressure-sensitive adhesive clearly showed strikethrough to the back of the nonwoven fabric. Was seen.

Comparative Example 2 The same acrylic copolymer pressure-sensitive adhesive solution 100 as in Example 1
To the part, ammonia water was added in such an amount as to neutralize 10% of the carboxyl groups in the acrylic copolymer pressure-sensitive adhesive solution, so that water became 15% in the water-containing pressure-sensitive adhesive solution, and mixed and stirred.
Water was separated, and a stable water-containing pressure-sensitive adhesive liquid was not obtained.

Comparative Example 3 The same pressure-sensitive adhesive solution as in Example 3 was applied to a nonwoven fabric in the same manner as in Example 1. Immediately after application, the pressure-sensitive adhesive clearly penetrated to the back surface of the nonwoven fabric.

Comparative Example 4 The same pressure-sensitive adhesive solution as in Example 3 was applied to a nonwoven fabric in the same manner as in Example 1, and a sealing agent was applied in the same manner as in Example 2. Therefore, application was difficult.

Comparative Example 5 When the same pressure-sensitive adhesive solution as in Example 5 was applied to a nonwoven fabric in the same manner as in Example 1, immediately after application, a large amount of strikethrough of the pressure-sensitive adhesive to the back surface of the nonwoven fabric was observed.

Comparative Example 6 The adhesive solution of Example 5 was weighed 2 in the same manner as in Example 1.
5 g / m ² nonwoven fabric (trade name Axter G2015-
8P, manufactured by Toray Industries, Inc.), it was found that the pressure-sensitive adhesive penetrated to the back surface of the nonwoven fabric immediately after the application.

[0058]

The pressure-sensitive adhesive of the present invention is obtained by neutralizing 1/5 to 1/1 of the carboxyl group of the acrylic copolymer having a carboxyl group in the molecule as the main component and mixing with water. Since it can be a water-containing pressure-sensitive adhesive liquid in which water is stably dispersed, it can stably blend and hold water-soluble substances such as water-soluble polymers and water-soluble crosslinkers, and have a wider range of properties than conventional pressure-sensitive adhesives. Obtainable.

Further, since the viscosity can be increased by using a water-containing pressure-sensitive adhesive liquid, even if the water-containing pressure-sensitive adhesive liquid is applied to a porous support at the time of forming the pressure-sensitive adhesive layer, the pressure-sensitive adhesive passes through the back surface of the support. Thus, pressure-sensitive adhesive sheets can be manufactured without a release paper, and a filler and a release agent can be uniformly applied to the back surface. Therefore, low-cost, high-quality adhesive sheets can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a pressure-sensitive adhesive tape which is one of examples of pressure-sensitive adhesive sheets of the present invention.

[Explanation of symbols]

 Reference Signs List 1 adhesive layer 2 support 3 filler

Claims (15)

[Claims] 1. A pressure-sensitive adhesive comprising a carboxyl group in a molecule and an acrylic copolymer in which 1/5 to 1/1 of the carboxyl group is neutralized as a main component. 2. An adhesive having a carboxyl group in the molecule and comprising as a main component an acrylic copolymer in which 1/5 to 1/1 of the carboxyl group has been neutralized. An adhesive characterized by containing. 3. A water-soluble polymer as a water-soluble substance and / or
The pressure-sensitive adhesive according to claim 2, further comprising a water-soluble crosslinking agent. 4. The pressure-sensitive adhesive according to claim 3, wherein the water-soluble polymer is compounded in an amount of 0.1 to 100 parts by weight based on 100 parts by weight of the acrylic copolymer in the pressure-sensitive adhesive. 5. The method according to claim 1, wherein one or both sides of the support are provided.
4. A pressure-sensitive adhesive sheet comprising a layer comprising the pressure-sensitive adhesive according to any one of 4). 6. The pressure-sensitive adhesive sheet according to claim 5, wherein the support is porous. 7. A support comprising a layer made of the pressure-sensitive adhesive according to claim 6 on one surface of the support, and a layer made of a filler on a surface of the support opposite to the surface having the pressure-sensitive adhesive. Pressure-sensitive adhesive sheets. 8. An organic solvent solution of a pressure-sensitive adhesive mainly containing an acrylic copolymer having a carboxyl group in a molecule is neutralized with 1/5 to 1/1 of the carboxyl group and mixed with water. By doing so, a water-containing pressure-sensitive adhesive liquid in which water is stably dispersed, the water-containing pressure-sensitive adhesive liquid is directly applied to one or both surfaces of the support, and dried to obtain a pressure-sensitive adhesive layer, characterized in that a pressure-sensitive adhesive layer is obtained. Production method. 9. The amount of water to be dispersed in the water-containing pressure-sensitive adhesive liquid is as follows:
The method for producing a pressure-sensitive adhesive sheet according to claim 8, wherein the content is 2 to 50% by weight based on 100% by weight of the water-containing pressure-sensitive adhesive liquid. 10. The method according to claim 8, wherein the concentration of the acrylic copolymer in the organic solvent solution is 10 to 50% by weight. 11. A method for producing a pressure-sensitive adhesive sheet, comprising forming a pressure-sensitive adhesive layer on a porous support by the method according to claim 8. 12. The method for producing pressure-sensitive adhesive sheets according to claim 8, wherein a water-soluble substance is blended with the water-containing pressure-sensitive adhesive liquid. 13. The method for producing a pressure-sensitive adhesive sheet according to claim 12, wherein a water-soluble polymer and / or a water-soluble crosslinking agent are blended as the water-soluble substance. 14. The method for producing pressure-sensitive adhesive sheets according to claim 13, wherein the water-soluble polymer is blended in an amount of 0.1 to 100 parts by weight based on 100 parts by weight of the acrylic copolymer in the pressure-sensitive adhesive. . 15. An adhesive characterized in that an adhesive layer is formed on one surface of a support by the method according to claim 8, and a filler is applied to the surface of the support opposite to the surface having the adhesive. Manufacturing method of sheets.