JPH05254069A - Water-absorbable self-adhesive sheet material and production thereof - Google Patents

Abstract

PURPOSE:To obtain a water-absorbable self-adhesive sheet material capable of being stably preserved in such a state that a release sheet is bonded and easily bonded to a place easy to generate a large amount of water or steam by providing a support layer to a fiber web having a water absorbable polymer bonded thereto through a specific self-adhesive layer to the opposite surface thereof. CONSTITUTION:A water-absorbable self-adhesive sheet material 4 is produced from a water-absorbable sheet self-adhesive layer A composed of a fiber web 2 having a water-absorbable polymer 3 bonded thereto, a support layer 1 and a self-adhesive layer B. As one example, a self-adhesive compounded with a crosslinking agent is applied on release paper 5 and, after a solvent is removed, the self-adhesive is transferred to the single surface of the support layer 1 to provide the self-adhesive layer A on the single surface of the support layer 1 and the polymer bonded surface of the water-absorbable sheet 4 is bonded to the self-adhesive layer A and, subsequently, the self-adhesive layer B is provided on the opposite surface of the support layer l in the same way as the self-adhesive layer A is provided to the single surface of the support layer 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water absorbent pressure sensitive adhesive sheet material. More specifically, the present invention can be easily attached to a place where a large amount of water or water vapor is likely to be generated, and can absorb a large amount of water or water vapor, and the peeling operation when removing from the attached object is easy, For example, the present invention relates to a novel water-absorbent pressure-sensitive adhesive sheet material useful as a dew condensation preventing material and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, a dew condensation preventing paint using a water-absorbing polymer for the purpose of absorbing water or absorbing moisture such as dew condensation is known (Japanese Patent Laid-Open No. 27176/1982). However, since such a dew condensation preventing coating is wet, it takes a lot of time to construct it, and when a water-based coating is used, the water-absorbing polymer swells and is difficult to handle.

In order to solve such a problem, there has been proposed a water-absorbent sheet in which a dew condensation preventing coating is adhered to a breathable sheet-shaped substrate and a back layer is further provided (Japanese Patent Publication No. 61-431).
93, JP-A-62-21140). on the other hand,
Condensation prevention wall formed by laminating a water-absorbent sheet formed by directly fixing a water-absorbent polymer to a fibrous web by polymerization of a water-soluble ethylenically unsaturated monomer forming the polymer with a water-resistant resin barrier layer interposed therebetween. A material has been proposed (JP-A-1-198943). This dew condensation preventing wall material prevents water from migrating from the water absorbing sheet to the paper by the water resistant resin barrier layer so that it does not peel off from the wall.

[0004]

A water-absorbent sheet made of the above anti-condensation coating is liable to drop off or move the water-absorbent polymer due to contact with other objects when it swells due to water absorption or moisture absorption, The fibrous web having the water-absorbent polymer attached thereto was not preferable because it easily peeled off from the back surface layer.

Further, the dew condensation preventing wall material formed by laminating a water-absorbent sheet and paper with a water-resistant resin barrier layer sandwiched therebetween swells the water-absorbent sheet when used in a high humidity atmosphere for a long time, resulting in a water-resistant resin barrier. There was a problem in terms of durability such as easy peeling from the layer, and it was not preferable. The water-absorbent pressure-sensitive adhesive sheet material having a pressure-sensitive adhesive layer on one surface of the water-absorbent sheet has a release paper attached to the surface of the pressure-sensitive adhesive layer, so that the release paper can be peeled off and attached to an object when in use. There is. However, when the adhesive paper is stored with the release paper attached, wrinkles occur in the water-absorbent adhesive sheet material due to humidity changes during that time, causing tunneling, or peeling from the release paper at the edge of the sheet material. If it happens, the commercial value will be lost.

According to the present invention, a release sheet such as a release paper can be stably stored in a state of being attached, and the release sheet can be easily attached to a place where a large amount of water or water vapor is easily generated. Water and water vapor can be absorbed, and there is no dropout, movement, peeling, etc. of the water-absorbed or moisture-absorbed water-absorbent polymer or water-absorbent sheet. An object of the present invention is to provide a water-absorbent pressure-sensitive adhesive sheet material which is easy and reliable and has a long-lasting dew condensation preventing effect when used as a dew condensation preventing material and has excellent durability.

[0007]

Means for Solving the Problems The inventors have provided a support layer on a fibrous web to which a water-absorbent polymer is adhered, via a specific pressure-sensitive adhesive layer A as described below, and the pressure-sensitive adhesive of the support layer is provided. It was found that the above problem can be solved by providing the pressure-sensitive adhesive layer B on the surface opposite to the layer A. That is, according to the present invention, the support layer 1 having the adhesive layer B on the surface is
The water-absorbent polymer 3 adhered to the fibrous web 2 is adhered to the one surface of the water-absorbent polymer fixed side of the water-absorbent sheet 4 via the pressure-sensitive adhesive layer A. The pressure-sensitive adhesive of the pressure-sensitive adhesive layer A and the water-absorbent polymer 3 A water-absorbent pressure-sensitive adhesive sheet material in which and are cross-linked with each other is provided (see FIG. 1).

In the present invention, as shown in FIG. 2, the water-absorbent sheet 41 is formed by fixing the water-absorbent polymer 3 to only one side of the fibrous web 2, and the water-absorbent polymer is fixed to the sheet 41. The support layer 1 may be attached to the surface via the adhesive layer A. In FIGS. 1 and 2, 5 is a release sheet. The water-absorbent sheet can be obtained, for example, by the following steps. When the water-absorbent polymer is obtained in this manner, the water-absorbent polymer is directly adhered to the fibrous web,
Even if there is no binder, it will not come off easily. However,
In the present invention, the water absorbent sheet is not limited to the one manufactured by such a process.

A water-soluble ethylenically unsaturated monomer that forms a water-absorbing polymer by polymerization (hereinafter, such a monomer is referred to as a monomer (a)) is attached to at least one side of the fibrous web. The monomer (a) attached to the fibrous web is converted into a water-absorbing polymer by a known polymerization method to obtain a fibrous web on which the water-absorbing polymer is fixed.

The fibrous web used in the present invention is not particularly limited as long as it is a breathable web, and can be appropriately selected and used according to the place, conditions and purpose of using the water-absorbent pressure-sensitive adhesive sheet material. Fiber webs such as papers, non-woven fabrics and woven fabrics made of fibers such as nylon, polyester, polyolefin, rayon, pulp and cellulose can be mentioned. The thickness of the fibrous web is not particularly limited, but when the fibrous web is left standing on a flat surface with the upper surface open, for example, 0.1
It is about 50 μm.

Examples of the monomer (a) include water-soluble ethylenically unsaturated monomers having a hydrophilic group such as a carboxyl group, a sulfonic acid group, an amide group, a hydroxyl group, a polyoxyalkylene group and an amino group. Has
Acrylic acid, methacrylic acid, 2- (meth) acryloylethanesulfonic acid, 2- (meth) acryloylpropanesulfonic acid, 2- (meth) acrylamido-2-methylpropanesulfonic acid, vinylsulfonic acid, (meth) allylsulfonic acid , And their alkali metal salts or ammonium salts such as lithium, sodium and potassium,
(Meth) acrylamide, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxy polyethylene glycol mono (meth) acrylate, methoxy polypropylene glycol mono (meth ) Acrylate and the like can be mentioned, and one or more of these can be used. Among them, (meth) acrylic acid and its salt, 2- (meth) acryloylethanesulfonic acid and its salt, and 2- (meth) are preferable.
It is at least one monomer selected from the group consisting of acrylamido-2-methylpropanesulfonic acid and salts thereof, and (meth) acrylamide. From the viewpoint of water absorption properties of the resulting water-absorbent pressure-sensitive adhesive sheet material, acrylic acid and its alkali metal salt are particularly preferable, and acrylic acid and its alkali metal salt are preferably contained in an amount of 50 mol% or more.

In the present invention, a crosslinking agent can be used when the monomer (a) is applied to the fibrous web and polymerized (hereinafter, such a crosslinking agent is referred to as a crosslinking agent (A)). The use of the cross-linking agent (A) is preferable from the viewpoint of adjusting the water absorption capacity of the water-absorbent polymer and enhancing the durability of the water-absorbent polymer. Examples of the cross-linking agent (A) to be used include poly (ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, N, N'-methylenebis (meth) acrylamide, trimethylolpropane tri (meth) acrylate, and the like. Examples thereof include compounds having two or more functional groups that react with a carboxyl group or a sulfonic acid group, such as functional ethylenically unsaturated monomers, ethylene glycol, polyethylene glycol, glycerin, ethylene glycol diglycidyl ether, and polyethylene glycol diglycidyl ether.

The use ratio of the monomer (a) and the crosslinking agent (A) is, for example, 0.005 to 5 parts by weight of the crosslinking agent (A) with respect to 100 parts by weight of the monomer (a). If it is out of this range, the water-absorbing pressure-sensitive adhesive sheet material obtained may have poor water-absorbing properties. The monomer (a) and optionally the crosslinking agent (A) are preferably used in the state of an aqueous solution. The solid content concentration of this aqueous solution is generally preferably in the range of, for example, 30% by weight to the saturated concentration.
Outside this range, the polymerizability of the monomer will decrease,
The water absorption or moisture absorption characteristics of the resulting water absorbent pressure sensitive adhesive sheet material may be deteriorated.

As a method for applying an aqueous solution containing the monomer (a) and a cross-linking agent (A) used as necessary to the fibrous web, a known printing method can be used.
Examples thereof include bar coaters, kiss coaters, gravure coaters, squeeze coaters, dip coaters, sprays, and brush coating. The monomer (a) may be attached to the entire surface or a part of both surfaces or one surface of the fibrous web, or to the entire fibrous web. When a water-absorptive pressure-sensitive adhesive sheet material using a water-absorptive sheet obtained by applying the monomer (a) to only one side of a fibrous web is stuck to a wall or the like, people or things come into direct contact with the water-absorptive polymer. This is preferable because it can be avoided.

As a preferred embodiment of the present invention, a cross-linking agent capable of reacting with either one of the water-absorbing polymer and the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer A on one surface of the fibrous web on which the water-absorbing polymer is adhered (Hereinafter, such a cross-linking agent will be referred to as a cross-linking agent (B)). The amount of the aqueous monomer solution attached to the fibrous web is not particularly limited, but in consideration of the water absorption characteristics and the moisture absorption characteristics of the resulting water absorbent pressure-sensitive adhesive sheet material,
After the polymerization, the water-absorbing polymer was 0.
It is preferable to attach the monomer aqueous solution so that 1 to 10 parts by weight are attached. When the amount of the polymer is less than 0.1 part by weight, the amount of water absorption and the amount of moisture absorption are small, and when the amount of the polymer exceeds 10 parts by weight, the amount of water absorption and the amount of moisture absorption do not increase so much, and the water absorption rate and the moisture absorption rate decrease. It is not preferable because it may happen.

The monomer (a) attached to the fibrous web
As a method for polymerizing the above, a conventionally known method can be used. For example, a method of polymerizing a monomer by irradiating a fiber web to which the monomer is attached with an electron beam; persulfate, hydrogen peroxide or 2,2′-azobis (2
-Amidino propane) dihydrochloride and the like are sandwiched between polymerization-inert surfaces by the action of a water-soluble radical polymerization initiator, or thermal polymerization is performed in an oven under a polymerization-inert atmosphere such as nitrogen gas or water vapor. And the like; a method of polymerizing by the action of an oxidizing initiator and a reducing agent; a method of photopolymerizing by irradiation of ultraviolet rays by the action of a photopolymerization initiator; and the like.

In the present invention, the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer A is a rubber-based pressure-sensitive adhesive or a silicone-based pressure-sensitive adhesive as long as it can be crosslinked by the crosslinking agent (B) capable of reacting with the water-absorbing polymer of the present invention. Although it can be selected from the above, it is preferable to use an acrylic pressure-sensitive adhesive from the viewpoint of durability and economy of the pressure-sensitive adhesive layer A. The acrylic pressure-sensitive adhesive may be either an aqueous emulsion type or a solvent type,
The solvent type is preferable in terms of durability.

The acrylic solvent-based pressure-sensitive adhesive that can be used in the pressure-sensitive adhesive layer A of the present invention is, for example, one or more kinds of (meth) acrylic acid alkyl ester whose alkyl group has 1 to 14 carbon atoms. (This is the main component);
An ethylenically unsaturated monomer having a functional group capable of reacting with the crosslinking agent (B) (hereinafter, such a monomer is referred to as a monomer (b)); and, if necessary, another ethylenically unsaturated monomer ( Hereinafter, such a monomer is referred to as a monomer (c)), a copolymer having a glass transition point of -20 ° C or lower obtained by copolymerizing a monomer mixture, and an organic solvent capable of dissolving or dispersing the copolymer. A solution or dispersion consisting of any of these can be used in the present invention.

Examples of the (meth) acrylic acid alkyl ester whose alkyl group has 1 to 14 carbon atoms include:
Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate ,
Tert-butyl (meth) acrylate, amyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate,
Heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate , Dodecyl (meth) acrylate and the like, and one or more of these can be used.

As the functional group that the monomer (b) may have, any conventionally known functional group may be used as long as it is a functional group capable of reacting with the cross-linking agent (B). Examples of the group include a carboxyl group and a hydroxyl group. Examples of the ethylenically unsaturated monomer having such a functional group, that is, the monomer (b) include, for example, (meth) acrylic acid, itaconic acid, a monoalkyl ester of itaconic acid, maleic acid, maleic anhydride, and a maleic acid monoester. Alkyl ester, fumaric acid, fumaric acid monoalkyl ester, acryloxypropionic acid,
Citraconic acid, monoalkyl citraconic acid ester,
Carboxyl group-containing ethylenically unsaturated monomer such as crotonic acid; obtained from hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, caprolactone-modified hydroxy (meth) acrylate, phthalic acid and propylene glycol Polyester diol mono (meth) acrylate, polyester diol mono (meth) acrylate obtained from phthalic acid and ethylene glycol, polyester diol mono (meth) acrylate obtained from succinic acid and propylene glycol,
Examples thereof include hydroxyl group-containing ethylenically unsaturated monomers such as mono (meth) acrylate of polyester diol obtained from succinic acid and ethylene glycol. Among them, (meth) acrylic acid and hydroxyethyl (meth) are preferable.
Acrylate, caprolactone modified hydroxy (meth)
One or more selected from acrylates.

Examples of the monomer (c) include:
Aliphatic unsaturated hydrocarbons such as ethylene and butadiene; halogen-substituted aliphatic unsaturated hydrocarbons such as vinyl chloride; aromatic unsaturated hydrocarbons such as styrene and α-methylstyrene; vinyl such as vinyl acetate Esters; vinyl ethers; esters of allyl alcohol and various organic acids and esters of various alcohols; unsaturated cyanide compounds such as acrylonitrile; unsaturated amide compounds such as acrylamide; butoxyethyl (meth) acrylate,
(Meth) acrylic acid ethyl carbitol ester, (meth) acrylic acid methyl triglycol ester, (meth) acrylic acid dipropylene glycol methyl ether ester, (meth) acrylic acid aryl ester, unsaturated methacrylic acid, crotonic acid, etc. Examples thereof include various esters of basic carboxylic acids, various diesters of unsaturated dibasic carboxylic acids such as maleic acid and fumaric acid, and one or more kinds selected from these can be used. be able to.

The ratio of the (meth) acrylic acid alkyl ester in which the alkyl group has 1 to 14 carbon atoms, the monomer (b) and the monomer (c) is not particularly limited, but for example, (meth) acrylic acid is used. Alkyl ester 1
The amount of the monomer (b) is 0.01 to 20 parts by weight, and the amount of the monomer (c) is 0 to 30 parts by weight with respect to 00 parts by weight. If it deviates from these ranges, it may be difficult to exert sufficient performance as an adhesive.

As the organic solvent used for the pressure-sensitive adhesive, any conventionally known one can be used as long as it can dissolve or disperse the copolymer, and the one used for the polymerization reaction can be used as it is. Is also good. From the viewpoint of easiness of production and storage stability of the acrylic solvent-based pressure-sensitive adhesive, it is preferable to use a solvent that dissolves the copolymer to prepare a solution. Examples of the organic solvent for obtaining such a solution include toluene and ethyl acetate. The ratio of the copolymer to the organic solvent is, for example, 50 to 300 parts by weight of the organic solvent with respect to 100 parts by weight of the copolymer, but is not limited thereto.

The acrylic solvent-based pressure-sensitive adhesive used in the present invention is a conventionally known method in which a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 14 carbon atoms, a monomer (b) and a monomer (c) are used. Is preferably solution-polymerized in the presence of an organic solvent, but the copolymer obtained by other methods such as emulsion polymerization, suspension polymerization, and bulk polymerization can be isolated and then dissolved in an organic solvent. ..

As the crosslinking agent (B), a compound having two or more isocyanate groups, a compound having two or more epoxy groups, a melamine compound, a guanamine compound,
Examples include oxazoline compounds and polyvalent metal compounds. Examples of the compound having two or more isocyanate groups include tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, 1,5-naphthalene diisocyanate, hydrogenated tolylene diisocyanate,
Diisocyanate compounds such as hydrogenated xylylene diisocyanate and isophorone diisocyanate; general formula (I) such as Sumidule N (Sumijour is a registered trademark, manufactured by Sumitomo Bayer Urethane Co.):

[0026]

[Chemical 1]

Burette polyisocyanate compound represented by: Desmodur IL, HL (Desmodur is a registered trademark, manufactured by Bayer AG (AG)),
Polyisocyanate compound having an isocyanurate ring such as Coronate EH (Coronate is a registered trademark; manufactured by Nippon Polyurethane Industry Co., Ltd.); Sumijour L (Sumijour is a registered trademark; Sumitomo Bayer Urethane Co., Ltd.); Coronate L (Coronate is a registered trademark. Chemicals (II) and (III) such as Nippon Polyurethane Industry Co., Ltd. and Coronate HL (Coronate is a registered trademark; Nippon Polyurethane Industry Co., Ltd.):

[0028]

[Chemical 2]

[0029]

[Chemical 3]

Examples thereof include an adduct polyisocyanate compound represented by The number of isocyanate groups contained in the molecule of the above-mentioned isocyanate compound is 2 or more, but those having more than 4 are usually difficult to obtain as commercial products. Those having Examples of those having two or more epoxy groups include polyglycidyl compounds such as trimethylolpropane triglycidyl ether and diglycidyl amine, and bisphenol A epichlorohydrin type epoxy resin. Specific examples of melamine compounds include precondensates of melamine-formaldehyde resins and their alkyl ethers; specific examples of guanamine compounds include precondensates of benzoguanamine, cyclohexanecarboguanamine, norbornanecarboguanamine and their alkyl ethers. And the like; isopropenyl oxazoline polymers and copolymers as oxazoline-based compounds; and aluminum trisacetylacetonate and zinc oxide as polyvalent metal compounds.

These crosslinking agents (B) can be used alone or in combination of two or more kinds. The amount of the cross-linking agent (B) used can be arbitrarily set depending on the type of the cross-linking agent (B), the composition of the pressure-sensitive adhesive, the type of water-absorbing polymer, etc., but generally 100 weight% of the copolymer used for the pressure-sensitive adhesive layer A 0 for the department.
The range of 01 to 10 parts by weight is preferable, and the range of 0.1 to 5 parts by weight is more preferable. When the amount of the cross-linking agent (B) is less than 0.01 parts by weight, the pressure-sensitive adhesive layer A creeps and deteriorates the water absorption or moisture absorption characteristics of the water absorbent sheet, or the cohesive failure of the pressure-sensitive adhesive layer A cannot be prevented. Sometimes. If it is more than 10 parts by weight, the adhesiveness between the pressure-sensitive adhesive layer A and the support layer may be lowered.

In the present invention, if necessary, a tackifier (a rosin ester resin, a phenol resin, a xylene resin, a xylene phenol resin, a terpene phenol resin, a petroleum resin, a coumarone resin, a low molecular weight styrene resin, a tackifier, etc. Terpene resin, etc.), thickener (polyvinyl alcohol, sodium polyacrylate, carboxymethyl cellulose, methyl cellulose, etc.), pH adjuster (ammonia, amine, sodium hydroxide, potassium hydroxide,
An appropriate amount of acetic acid, boric acid, phosphoric acid, etc.), colorants (pigments, dyes, etc.), plasticizers, softeners, antioxidants, fillers, viscosity modifiers, etc. may be contained.

The thickness of the pressure-sensitive adhesive layer A is, for example, 1 to 20.
It is 0 μm, preferably 10 to 100 μm. If the thickness is less than 1 μm, the adhesiveness may be poor. Also,
If it is thicker than 200 μm, the water-absorbent pressure-sensitive adhesive sheet material may have poor water absorption or moisture absorption characteristics. The support layer used in the present invention is essential in order to obtain excellent dimensional stability of the water-absorbent pressure-sensitive adhesive sheet material of the present invention and workability during sticking and peeling removal. Suitable support layers are uniform or porous sheet-like or woven or non-woven fabrics, for example polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, ethylene-vinyl acetate copolymers, polystyrene, polyamide, ethylene- α-
A thermoplastic resin selected from olefin copolymers, ethylene-α, β-unsaturated carboxylic acid ester copolymers, thermoplastic elastomers, or polyurethane resins, unsaturated polyester resins, amino resins, phenol resins, and various Examples include single-layer or multi-layer materials such as paper, rubber and metal. Among these, since it is easy to obtain dimensional stability, toughness, flexibility, etc. when used in the water-absorbent pressure-sensitive adhesive sheet material of the present invention, a uniform sheet-shaped thermoplastic resin, polyurethane resin, unsaturated resin It is preferable to use one or more polyester resins.

The thickness of the support layer is appropriately selected according to the type of material used for the support layer, but is usually 1 to 200 μm.
m. If necessary, the surface of the support layer is subjected to corona discharge treatment or primer coating treatment by a conventionally known method or the like depending on the type of the support layer to adhere to the pressure-sensitive adhesive layer A and / or the pressure-sensitive adhesive layer B. It is also possible to improve the sex.

In the present invention, the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer B is not particularly limited, and conventionally known pressure-sensitive adhesives such as acrylic pressure-sensitive adhesives, rubber pressure-sensitive adhesives and silicone pressure-sensitive adhesives can be used. From the viewpoint of the durability of the pressure-sensitive adhesive layer B, an acrylic solvent-based pressure-sensitive adhesive is preferable, and further, an acrylic solvent-based pressure-sensitive adhesive that is crosslinked by the crosslinking agent used in the above-mentioned pressure-sensitive adhesive layer A is preferable. Therefore, the same adhesive as the adhesive layer A can be used for the adhesive layer B.

The acrylic solvent-based pressure-sensitive adhesive used in the pressure-sensitive adhesive layer B of the present invention has an appropriate sticking property depending on the type of the adherend to which the water-absorbent pressure-sensitive adhesive sheet material of the present invention is stuck, and is peeled off after sticking. In order to obtain the ease of peeling,
The glass transition temperature, crosslink density, polarity, molecular weight and the like can be adjusted as appropriate. The thickness of the adhesive layer B is, for example, 1
˜200 μm, preferably 10 to 100 μm. 1
When it is thinner than μm, the adhesiveness is poor, and when it is thicker than 200 μm, after the water-absorbing pressure-sensitive adhesive sheet material of the present invention is applied,
When peeled off, problems such as the adhesive remaining on the adherend are likely to occur.

The water-absorbent pressure-sensitive adhesive sheet material of the present invention is used as a water-absorbent sheet comprising a fibrous web to which a water-absorbent polymer is attached,
The method for producing the pressure-sensitive adhesive layer A, the support layer, and the pressure-sensitive adhesive layer B is as follows, for example. (Method 1) A pressure-sensitive adhesive containing a cross-linking agent (B) is directly coated on one surface of a support layer to remove the solvent, or coated on release paper to remove the solvent, and then the support layer The adhesive layer A is provided on one side of the support layer, the polymer-attached surface of the water-absorbent sheet is attached to the adhesive layer A, and then the pressure-sensitive adhesive is applied to the one side of the support layer. The pressure-sensitive adhesive layer B is provided on the opposite surface of the support layer in the same manner as when the layer A is provided.

(Method 2) A pressure-sensitive adhesive containing a cross-linking agent (B) is directly coated on one side of the support layer, the solvent is removed to form a pressure-sensitive adhesive layer A on one side of the support layer, and then the same step is carried out. Inside, the pressure-sensitive adhesive layer A and the polymer-adhered surface of the water-absorbent sheet are bonded together. Then, the pressure-sensitive adhesive layer B is provided on the opposite surface of the support layer in the same manner as in Method 1.

(Method 3) A pressure-sensitive adhesive layer A and a pressure-sensitive adhesive layer B are respectively provided on the two surfaces of the support layer in the same manner as in the method 1, and then the pressure-sensitive adhesive layer A is provided with the polymer-adhering surface of the water-absorbent sheet. to paste together. In this method 3, a double-sided pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer A provided on one surface of a support layer and a pressure-sensitive adhesive layer B on the other surface is prepared.
And a method of bonding the surface to the polymer-attached surface of the water absorbent sheet.

(Method 4) When the support layer is porous, the support layer is impregnated with a pressure-sensitive adhesive containing a crosslinking agent (B) and the solvent is removed to remove the solvent. The pressure-sensitive adhesive layer A is provided on both surfaces of, and then the polymer-adhered surface of the water-absorbent sheet is bonded to the surface of one pressure-sensitive adhesive layer A. (Method 5) A pressure-sensitive adhesive containing a cross-linking agent (B) is directly applied on the polymer-attached surface of the water-absorbent sheet to remove the solvent, or preferably on release paper to remove the solvent. Then, the pressure-sensitive adhesive layer A is provided on the polymer-attached surface of the water-absorbent sheet, then the support layer is attached to the opposite surface of the pressure-sensitive adhesive layer A, and finally the pressure-sensitive adhesive is applied on the opposite surface of the support layer in the same manner as in Method 1. Layer B is provided.

(Method 6) Adhesive layer A provided on the polymer-adhered surface of the water-absorbent sheet in the same manner as in Method 5 and the opposite surface of the support layer provided with adhesive layer B on one surface in the same manner as in Method 1. And paste together. (Method 7) A pressure-sensitive adhesive is directly applied to one surface of the support layer, the solvent is removed to provide a pressure-sensitive adhesive layer B on one surface of the support layer, and subsequently, in the same step, the opposite surface of the support layer and the method In the same manner as in 5, the pressure-sensitive adhesive layer A provided on the adhering surface of the water absorbent sheet in advance is attached.

(Method 8) In the same manner as in Method 5, the pressure-sensitive adhesive layer A is provided on the polymer-adhered surface of the water-absorbent sheet, and then the pressure-sensitive adhesive layer A and the support layer are attached in the same step, and then the support layer. The pressure-sensitive adhesive layer B is provided on the surface opposite to the above in the same manner as in Method 1. In each of the above methods, the pressure-sensitive adhesive layer A,
The pressure-sensitive adhesive layer B may be provided on the entire surface of the water-absorbent sheet or the support layer, or may be provided discontinuously in various patterns such as stripes, polka dots, and grids, if necessary. .. When the pressure-sensitive adhesive layer A is provided, it is preferable that the pressure-sensitive adhesive layer A is provided so as not to substantially impair the water absorption / moisture absorption characteristics of the water absorbent polymer. For example, the pressure-sensitive adhesive layer A does not excessively permeate the fibrous web to which the water-absorbent polymer is attached so as not to impair the water absorption / moisture absorption characteristics of the water-absorbent polymer.

In addition to those described in the above respective steps, a release sheet such as release paper having a release treatment on one side or both sides can be used if necessary.
Furthermore, after obtaining the water-absorbent pressure-sensitive adhesive sheet material of the present invention, it is preferable from the viewpoint of handling that the release surface of a release sheet such as a release paper subjected to a one-side release treatment is applied to the exposed surface of the pressure-sensitive adhesive layer B.

In the above-mentioned method, the pressure-sensitive adhesive layer A obtained by applying the pressure-sensitive adhesive containing the cross-linking agent (B) and removing the solvent is promptly added to the polymer of the water-absorbent sheet for the reason described below. It is necessary to attach the attachment surfaces. Among the above methods, Method 2 is preferable from the viewpoint of simplicity and economy. When the pressure-sensitive adhesive containing the cross-linking agent (B) is applied and the solvent is removed, the pressure-sensitive adhesive layer A has fluidity, and in this state, the water-absorbent polymer adheres to the polymer-adhered surface of the fibrous web. When the pressure-sensitive adhesive layer A is provided, a part of the water-absorbent polymer and the fibrous web are embedded and firmly bonded. Since the pressure-sensitive adhesive layer A contains the crosslinking agent (B), the fluidity of the pressure-sensitive adhesive layer A is lost with the passage of time (heating may be performed if necessary). Therefore, the adhesion between the pressure-sensitive adhesive layer A and the fibrous web becomes stronger, and the water-absorbent sheet is not peeled from the sticking surface.
Further, since the creep of the pressure-sensitive adhesive does not occur, the coating of the water-absorbing polymer due to the creep does not occur. Therefore, the water absorption / moisture absorption characteristics of the water absorbent sheet can be maintained for a long period of time. In the present invention, since the pressure-sensitive adhesive layer A contains the water-absorbing polymer and the crosslinking agent capable of reacting with the pressure-sensitive adhesive, when the water-absorbing polymer swells due to water absorption / moisture absorption, The effect that peeling does not occur with the polymer is exhibited. Further, the water absorption / moisture absorption characteristics of the water-absorbent polymer are not deteriorated by the pressure-sensitive adhesive layer A.

In the present invention, an antifungal agent can be used if necessary. Examples of the fungicide include benzimidazole compounds, phenol compounds, thiazole compounds and the like. One or more of these antifungal agents can be used. These fungicides can be added to any part of the fibrous web, the water-absorbent polymer, the pressure-sensitive adhesive layer A, the pressure-sensitive adhesive layer B, and the support layer.

Further, it is possible to prevent the formation of mold by copolymerizing (meth) acrylic acid alkyl ester having a quaternary ammonium group or N-substituted (meth) acrylamide with a water-absorbing polymer or a monomer forming an adhesive. You can also

[0047]

The support layer having the pressure-sensitive adhesive layer B provided on the surface thereof is adhered to the surface of the water-absorbent sheet having the water-absorbent polymer fixed to the fibrous web via the pressure-sensitive adhesive layer A. In the water-absorbent pressure-sensitive adhesive sheet material thus obtained, when the pressure-sensitive adhesive of the pressure-sensitive adhesive layer A and the water-absorbent polymer are cross-linked, the pressure-sensitive adhesive layer A is absorbed even when the water-absorbent polymer absorbs water or absorbs moisture.
And the water-absorbent polymer are bonded. Therefore, peeling between the water absorbent sheet and the support layer is unlikely to occur. Moreover, the water-absorbent pressure-sensitive adhesive sheet material is easy to handle and has good water-absorption / moisture-absorption characteristics.

[0048]

EXAMPLES Specific examples and comparative examples of the present invention will be shown below, but the present invention is not limited to the following examples. Reference Example 1- 100 parts by weight of a partially neutralized acrylic acid aqueous solution (monomer concentration 37% by weight) in which 75% is neutralized with sodium hydroxide, 1.3 parts by weight of N, N'-methylenebisacrylamide, sodium persulfate 0.2 parts by weight and 0.7 parts by weight of hydroxyethyl cellulose were dissolved, and then dissolved oxygen in the monomer aqueous solution was removed with nitrogen gas.

After impregnating the entire surface of a polypropylene nonwoven fabric having a basis weight of 22 g / m ² with this monomer aqueous solution, the amount of the squeezed monomer aqueous solution was set to 100 g / m ² . Next, the non-woven fabric having the aqueous monomer solution adhered to the entire surface was kept at 120 ° C. for 5 minutes in a nitrogen atmosphere to polymerize the monomer to obtain a water absorbent sheet (1) made of a fibrous web having the water absorbent polymer adhered to the entire surface. ..

Reference Example 2 In Reference Example 1, a rayon-polyester blended nonwoven fabric having a basis weight of 95 g / m ² was kiss coated on one side with the aqueous monomer solution used in Reference Example 1 so as not to be exposed on the opposite side of the nonwoven fabric. Other than the same as in Reference Example 1, a water-absorbent sheet (2) made of a fibrous web having a water-absorbent polymer attached to one side.
Got

Reference Example 3 A water absorbent sheet (3) was obtained in the same manner as in Reference Example 2 except that the fibrous web used in Reference Example 2 was paper having a basis weight of 40 g / m ² . Reference Example 4-A water absorbent sheet (4) was obtained in the same manner as in Reference Example 2 except that a polypropylene spunbonded nonwoven fabric having a basis weight of 60 g / m ² was used for the fibrous web.

Reference Example 5 Reference Example 1 is the same as Reference Example 1 except that the amount of N, N′-methylenebisacrylamide used was 0.06 parts by weight and a polyester nonwoven fabric having a basis weight of 100 g / m ² was used as the fibrous web. A water absorbent sheet (5) was obtained in the same manner as in Example 1. -Reference Example 6- 100% partially neutralized acrylic acid aqueous solution (monomer concentration 60% by weight) in which 75 mol% was neutralized with potassium hydroxide 100
1.8 parts by weight of N, N'-methylenebisacrylamide
By weight, 0.3 parts by weight of sodium persulfate and 0.6 parts by weight of hydroxyethyl cellulose were dissolved, and then dissolved oxygen was removed from the aqueous monomer solution with nitrogen gas.

This monomer aqueous solution was kiss-coated on one side of a nylon spunbonded nonwoven fabric having a basis weight of 60 g / m ^{2 so} that the monomer aqueous solution would not be exposed on the opposite side,
The amount of the monomer aqueous solution attached was 90 g / m ² . The nonwoven fabric to which the aqueous monomer solution was attached was held at 90 ° C. for 10 minutes to polymerize the monomer in a nitrogen atmosphere. Continue 1
Water-absorbent sheet (6) made of a fibrous web dried on a hot-air dryer at 10 ° C for 20 minutes and having a water-absorbent polymer attached to one side.
Got

Reference Example 7 In a 3 liter flask equipped with a thermometer, a cooling condenser, a nitrogen introducing tube and a stirrer, 150 parts by weight of toluene, 450 parts by weight of butyl acrylate, 10 parts by weight of hydroxyethyl acrylate and 2 parts of acrylic acid were placed. -Ethylhexyl 450 parts by weight, acrylic acid 40 parts by weight, vinyl acetate 5
0 part by weight was charged and the temperature was raised to 80 ° C. with stirring under a nitrogen stream. Next, 2 parts by weight of benzoyl peroxide was added as a polymerization initiator, and the mixture was stirred at the same temperature for 2 hours. Then, 1 part by weight of benzoyl peroxide was added and the mixture was further stirred for 2 hours. A polymer solution was obtained.

Then, 8 parts by weight of pentaline C as a tackifier was added to 100 parts by weight of the obtained copolymer solution.
(Rika Hercules Co., Ltd., polymerized rosin ester,
(Softening point: 123 ° C.) and added, and 1 part by weight of Coronate L-55E (Coronate is a registered trademark) (Nippon Polyurethane Industry Co., Ltd., trifunctional isocyanate cross-linking agent) is added as a cross-linking agent to make it non-volatile. A pressure-sensitive adhesive composition (1) having a content of 44.5% by weight was obtained.

Reference Example 8-0.7 parts by weight of Coronate L-5 based on 100 parts by weight of the copolymer solution having a nonvolatile content of 40% by weight obtained in Reference Example 7
5E (Coronate is a registered trademark) (manufactured by Nippon Polyurethane Industry Co., Ltd., a trifunctional isocyanate crosslinking agent) was added to obtain an adhesive composition (2) having a nonvolatile content of about 40% by weight.

Comparative Reference Example 1-A cross-linking agent-free comparative pressure-sensitive adhesive composition (1) was obtained in the same manner as in Reference Example 7 except that the crosslinking agent Coronate L-55E was not added. It was -Example 1-The pressure-sensitive adhesive composition (1) obtained in Reference Example 7 was coated on one surface of a polyethylene terephthalate sheet having a thickness of 16 µm with an applicator so that the thickness after drying was 50 µm, and 80
After being left in an atmosphere of ℃ for 3 minutes to remove the solvent, the water absorbent sheet (1) obtained in Reference Example 1 was laminated.
On the opposite side of the polyethylene terephthalate sheet of the obtained laminate, the pressure-sensitive adhesive composition (2) obtained in Reference Example 8 was separately coated on a release paper with an applicator so that the thickness after drying was 25 μm. Similarly, the pressure-sensitive adhesive layer obtained by removing the solvent was transferred from the release paper, and the water-absorbent pressure-sensitive adhesive sheet material (1) of the present invention was obtained with the release paper adhered.

-Example 2-A pressure-sensitive adhesive composition (1) obtained in Reference Example 7 was coated on one surface of a polypropylene sheet having a thickness of 16 µm whose both surfaces were subjected to corona discharge treatment with an applicator so that the thickness after drying was 50 µm. Then, the solvent was removed by leaving it in an atmosphere of 80 ° C. for 3 minutes, and then the surface of the water absorbent sheet (2) obtained in Reference Example 2 was attached to the surface having the water absorbent polymer adhered thereto. On the opposite surface of the polypropylene sheet of the obtained laminate, the pressure-sensitive adhesive composition (2) obtained in Reference Example 8 was separately coated on a release paper with an applicator so that the thickness after drying was 25 μm, and the same as above. The pressure-sensitive adhesive layer obtained by removing the solvent was transferred from the release paper, and the water-absorbent pressure-sensitive adhesive sheet material (2) of the present invention was obtained with the release paper stuck.

Example 3 In Example 2, except that a polyethylene sheet having a thickness of 40 μm whose both surfaces were subjected to corona discharge treatment was used as the support and the water absorbent sheet (3) obtained in Reference Example 3 was used as the water absorbent sheet. In the same manner as in Example 2, a water-absorbent pressure-sensitive adhesive sheet material (3) of the present invention was obtained.

-Example 4-A water-absorbent pressure-sensitive adhesive sheet material (4) according to the present invention is the same as in Example 2 except that the water-absorbent sheet (4) is used instead of the water-absorbent sheet (2). Got -Example 5-A water absorbent pressure-sensitive adhesive sheet material (5) of the present invention was obtained in the same manner as in Example 1 except that the water absorbent sheet (5) was used in place of the water absorbent sheet (1). ..

-Example 6-A water-absorbent pressure-sensitive adhesive sheet material (6) according to the present invention was used in the same manner as in Example 2 except that the water-absorbent sheet (6) was used instead of the water-absorbent sheet (2). Got -Comparative Examples 1-6-Examples 1-6, except that the comparative pressure-sensitive adhesive composition (1) was used as the pressure-sensitive adhesive for bonding the support and the water absorbent sheet, respectively. Comparative water absorbent pressure-sensitive adhesive sheet materials (1) to (6) were obtained in the same manner as in.

Comparative Example 7 The pressure-sensitive adhesive composition (1) obtained in Reference Example 7 was coated on a release paper so that the thickness after drying was 50 μm, and left in an atmosphere at 80 ° C. for 3 minutes. After removing the solvent, the water-absorbent sheet (1) was then laminated on one side to obtain a comparative water-absorbent pressure-sensitive adhesive sheet material (7) having no support in the state where the release paper was attached.

Comparative Example 8 Comparative Example 7 is the same as Comparative Example 7 except that the water absorbent sheet (1) is bonded to one surface of the water absorbent sheet (2) instead of the one surface of the water absorbent sheet (1). Similarly, a comparative water absorbent pressure-sensitive adhesive sheet material (8) having no support was obtained. -Comparative Example 9-A comparative water-absorbent pressure-sensitive adhesive sheet material (9) having no support in the same manner as in Comparative Example 8 except that the water-absorbent sheet (3) was used instead of the water-absorbent sheet (2) in Comparative Example 8. Got

-Comparative Example 10-A comparative water-absorbing pressure-sensitive adhesive sheet material having no support in the same manner as in Comparative Example 8 except that the water-absorbing sheet (4) was used instead of the water-absorbing sheet (2). (10) was obtained. -Comparative Example 11-A comparative water-absorbent pressure-sensitive adhesive sheet material (11) having no support in the same manner as in Comparative Example 7 except that the water-absorbent sheet (5) was used instead of the water-absorbent sheet (1). Got

-Comparative Example 12-A comparative water-absorbent pressure-sensitive adhesive sheet material having no support in the same manner as in Comparative Example 8 except that the water-absorbent sheet (6) was used instead of the water-absorbent sheet (2). (12) was obtained. (Dip test) When the water-absorbent pressure-sensitive adhesive sheet materials (1) to (6) obtained in Examples 1 to 6 were attached to an acrylic plate and immersed in pure water, the water-absorbent pressure-sensitive adhesive sheet materials (1) to (6) were obtained. Did not peel at the interface between the fibrous web and the pressure-sensitive adhesive layer even after swelling of the water-absorbent polymer, and did not peel even when pressed with a finger. For comparison, comparative water absorbent pressure-sensitive adhesive sheet materials (1) to (12) were similarly attached to an acrylic plate and immersed in pure water. As a result, the comparative water-absorbent pressure-sensitive adhesive sheet materials (7) to (12) did not peel at the interface between the fibrous web and the pressure-sensitive adhesive layer even after swelling of the water-absorbent polymer, and did not peel even when pressed with a finger. The water-absorbent pressure-sensitive adhesive sheet materials (1) to (6) were peeled off at the interface between the fibrous web and the pressure-sensitive adhesive layer after lightly pressing the finger after swelling of the water-absorbent polymer. In each of the water-absorbent pressure-sensitive adhesive sheet materials obtained in Examples and Comparative Examples, the water-absorbent polymer did not fall off from the fibrous web during swelling of the water-absorbent polymer. (Workability when reattaching) Water-absorbent pressure-sensitive adhesive sheet material (1) to
In the case of (6), when it was attached to an acrylic plate, it could be easily peeled off to correct the position after it was once attached, and the reattachability was good. Comparative water absorbent pressure-sensitive adhesive sheet materials (7) to (1
2) is the water-absorbent pressure-sensitive adhesive sheet material (1) in the immersion test
The results are similar to those of (6). However, when the sheet material is attached to an acrylic plate, the sheet material stretches easily when it is peeled off to correct the position after the edge portion of the sheet material is once attached. The sheet material could not be peeled off, and after peeling, the sheet material was partially deformed, and the reattachability was not good. (Workability during peeling) Water-absorbent pressure-sensitive adhesive sheet materials (1) to (6)
Was able to be easily and completely peeled off even after one month or more had been applied to the acrylic plate. On the other hand, when the comparative water-absorbent pressure-sensitive adhesive sheet materials (7) to (12) are peeled off after a lapse of one month or more after being attached to the acrylic plate, they are easily broken and it is difficult to completely peel them. It was (Storage stability) Water-absorbent pressure-sensitive adhesive sheet materials (1) to (6) in an atmosphere having a relative humidity of 70% at 30 ° C. and an atmosphere of 40% relative humidity at 10 ° C. with release paper attached. Were left for 6 hours respectively, but the water-absorbent pressure-sensitive adhesive sheet material (1)
In the case of (6), no tunneling due to wrinkles on the release paper and peeling from the release paper at the edges did not occur in any atmosphere. When the comparative water-absorbent pressure-sensitive adhesive sheet materials (1) to (12) were left in the same manner, the comparative water-absorbent pressure-sensitive adhesive sheet material (1)
No abnormalities were observed in (6) to (6), but the comparative water-absorbent pressure-sensitive adhesive sheet materials (7) to (12) had a relative humidity of 70 at 30 ° C.
%, Many tunneling due to wrinkles occurred on the release paper, and peeling from the release paper at the edges was observed under the atmosphere of 10 ° C. and 40% relative humidity. (Water Absorption Performance) Water Absorption The water absorbent pressure-sensitive adhesive sheet materials (1) to (6) of the present invention were immersed in pure water and then pulled up, sufficiently drained, and then weighed to determine the water absorption amount by the following formula. .. Water absorption (g / m ² ) = [(weight of water-absorbent pressure-sensitive adhesive sheet material after immersion)-(weight of water-absorbent pressure-sensitive adhesive sheet material before immersion)] /
(Area of Water-Absorbing Adhesive Sheet Material) The water-absorbing amount was calculated by the following formula in the same manner for the water-absorbing sheets (1) to (6) used for the water-absorbing adhesive sheet materials (1) to (6), respectively. Water absorption (g / m ² ) = [(weight of water-absorbent sheet after immersion)
-(Weight of water-absorbent sheet before immersion)] / (Area of water-absorbent sheet) The obtained amount of water absorption is summarized in Table 1.

[0066]

[Table 1] Water absorption [g / m ² ] ────────────────────── Water absorbent pressure sensitive adhesive sheet material (1) 3000 Water absorbent pressure sensitive adhesive sheet material (2 ) 2000 water-absorbing adhesive sheet material (3) 2500 water-absorbing adhesive sheet material (4) 3000 water-absorbing adhesive sheet material (5) 10000 water-absorbing adhesive sheet material (6) 3000 ───────────── ────────── As shown in Table 1, the adhesive layer A,
Even if the support layer and the pressure-sensitive adhesive layer B are provided, the water absorption performance of the water absorbent sheet is not impaired.

Dew Condensation Preventing Property When ice water at 5 ° C. was placed in a glass beaker in an atmosphere of temperature 25 ° C. and relative humidity 60%, water droplets immediately formed on the outer surface of the beaker, and dew condensation occurred. Stick the water-absorbent pressure-sensitive adhesive sheet materials (1) to (6) on the outer peripheral surface of the glass beaker,
When ice water was added in the same manner, dew condensation did not occur at all in the beaker, and the water-absorbent pressure-sensitive adhesive sheet material was not peeled off from the beaker at all. Water-absorbent pressure-sensitive adhesive sheet material (2), (3),
The surfaces of (4) and (6) remained dry, and the surfaces of the water-absorbent pressure-sensitive adhesive sheet materials (1) and (5) were slightly moist.

Comparative water-absorbent pressure-sensitive adhesive sheet materials (1) to (6) were similarly attached to a glass beaker and ice water was added,
Although dew condensation did not occur at all, when left for a while, the fibrous web and the pressure-sensitive adhesive layer started to peel off at the edge portion of the comparative water-absorbent pressure-sensitive adhesive sheet material. Drip absorption capacity When a frozen crab and a commercially available ice pack were put in a Styrofoam container, a large amount of water was accumulated in the container.

When the water-absorbent pressure-sensitive adhesive sheet material (2) obtained in Example 2 was attached to the inner wall of a Styrofoam container in the same manner as above, the inside did not get wet and remained dry, and the water-absorbent pressure-sensitive adhesive sheet material (2 ) Also did not separate from the inner wall.
When the comparative water absorbent pressure-sensitive adhesive sheet material (2) was used in the same manner,
Although the inside did not get wet and it remained dry, the fibrous web was partly peeled from the pressure-sensitive adhesive layer.

[0070]

The water-absorbent pressure-sensitive adhesive sheet material of the present invention has the following effects. The adhesive makes it easy to apply to places where water or water vapor is likely to occur, and has excellent reattachability. When the pressure-sensitive adhesive layer and the water-absorbing polymer are cross-linked by including a water-absorbing polymer and a crosslinking agent capable of reacting with the pressure-sensitive adhesive in the pressure-sensitive adhesive layer, the water-absorbing polymer absorbs water.
The effect that peeling does not occur between the pressure-sensitive adhesive layer and the water-absorbent polymer when it absorbs moisture and swells is exhibited. Also,
The water-absorbing / moisture-absorbing properties of the water-absorbent polymer are not deteriorated by the pressure-sensitive adhesive layer.

Furthermore, since the water-absorbent pressure-sensitive adhesive sheet material of the present invention is provided with the support layer, the following effects are also exhibited. It can be stably stored with a release sheet such as release paper attached, and has excellent durability after being attached to an object, and the water-absorbent pressure-sensitive adhesive sheet material of the present invention can be attached even after long-term use. It is difficult for the target object to peel off naturally, and it can be easily peeled off when separating and removing.

In the present invention, if the water-absorbent polymer is attached to the fibrous web by polymerization of the monomer forming the polymer, the following effects are also exhibited. The polymer does not drop off or migrate from the fibrous web when absorbing large amounts of water or water vapor. Further, in the present invention, the water-absorbent polymer is not exposed on the surface by providing the pressure-sensitive adhesive layer on the polymer-adhered surface of the fibrous web to which the water-absorbent polymer is adhered on one surface. People and things do not come into direct contact with the water-absorbent polymer, and the texture of the surface becomes good. Even when a large amount of aqueous liquid or water vapor is absorbed, the dry feeling of the surface of the water absorbent sheet is maintained and the texture becomes good. It is possible to easily print a design or the like on the water absorbent sheet.

Therefore, since the water-absorbent pressure-sensitive adhesive sheet material of the present invention has the above-mentioned advantages, it can be used for walls of rooms, basements, warehouses, etc.
Condensation or liquid leakage on the ceiling, floor, closet, inside wall of container, inside Styrofoam container used for frozen courier service, inside cardboard box, inside plastic bag, entrance, entrance of bathroom, under windows, etc. It is applied directly to the places where it is easy to get rid of, and it has an excellent effect of preventing dew condensation and liquid leakage. In addition, when applied to containers such as Styrofoam and corrugated cardboard, it can be suitably used for keeping the freshness of fresh food in these containers and absorbing drip. However, the use of the water-absorbent pressure-sensitive adhesive sheet material of the present invention is not limited to those listed here.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of a water-absorbent pressure-sensitive adhesive sheet material of the present invention.

FIG. 2 is a side sectional view showing another embodiment of the water-absorbent pressure-sensitive adhesive sheet material of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Support layer 2 Fiber web 3 Water-absorbent polymer 4 Water-absorbent sheet 5 Release paper 41 Water-absorbent sheet A Adhesive layer A B Adhesive layer B

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location B32B 27/30 A 8115-4F E04B 1/64 D

Claims (10)

[Claims] 1. A support layer having a pressure-sensitive adhesive layer B on the surface of a water-absorbent sheet formed by fixing a water-absorbent polymer to a fibrous web, with a pressure-sensitive adhesive layer A on one side A water-absorbent pressure-sensitive adhesive sheet material, which is adhered and in which the pressure-sensitive adhesive of the pressure-sensitive adhesive layer A and the water-absorbent polymer are cross-linked with each other. 2. A support layer having a pressure-sensitive adhesive layer B on the surface thereof, wherein the water-absorbent polymer is fixed to only one side of the fibrous web, and the pressure-sensitive adhesive layer is fixed to the water-absorbent polymer fixed surface. A water-absorbent pressure-sensitive adhesive sheet material, which is adhered via A and in which the pressure-sensitive adhesive of the pressure-sensitive adhesive layer A and the water-absorbent polymer are cross-linked with each other. 3. The water-absorbent pressure-sensitive adhesive sheet material according to claim 1, wherein the water-absorbent polymer is directly adhered to the fiber web by polymerization of water-soluble ethylenically unsaturated monomer attached to the fiber web. 4. The water-absorbent pressure-sensitive adhesive sheet material according to claim 1, wherein the water-absorbent polymer has a carboxyl group. 5. The water-absorbent pressure-sensitive adhesive sheet material according to claim 1, wherein the pressure-sensitive adhesive layer A is made of an acrylic solvent-based pressure-sensitive adhesive. 6. The water-absorbent pressure-sensitive adhesive sheet material according to claim 1, wherein the pressure-sensitive adhesive layer B is made of an acrylic solvent-based pressure-sensitive adhesive. 7. The pressure-sensitive adhesive layer A contains a crosslinking agent capable of reacting with both the water-absorbing polymer and the pressure-sensitive adhesive of the pressure-sensitive adhesive layer A, and the crosslinking agent causes the pressure-sensitive adhesive and the water-absorbing polymer to mutually react. The water-absorbent pressure-sensitive adhesive sheet material according to any one of claims 1 to 6, which is crosslinked. 8. The water-absorbent pressure-sensitive adhesive sheet material according to claim 7, wherein the crosslinking agent is a compound having at least two functional groups selected from an isocyanate group and an epoxy group. 9. The water-absorbent pressure-sensitive adhesive sheet material according to any one of claims 1 to 8, wherein a release sheet is attached to the surface of the pressure-sensitive adhesive layer B. 10. A water-absorbent sheet having a water-absorbent polymer adhered to a fibrous web, a pressure-sensitive adhesive layer A, a support layer, and
A method for producing a water-absorbent pressure-sensitive adhesive sheet material in which the pressure-sensitive adhesive layer B is sequentially laminated, wherein the pressure-sensitive adhesive used for forming the pressure-sensitive adhesive layer A can react with either the pressure-sensitive adhesive or the water-absorbent polymer. A method for producing a water-absorbent pressure-sensitive adhesive sheet material, which comprises containing a crosslinking agent.