JPH09272806A - Water absorbing resin dispersion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a readily producible water absorbing resin dispersion, having a fine particle diameter and good in dispersion stability. SOLUTION: This water absorbing resin dispersion is obtained by dispersing (B) a water absorbing resin or its water absorbing gel in (A) one or more plasticizers selected from the group of carboxylic acid esters, phosphoric esters, epoxidized vegetable oils and chlorinated plasticizers. The component B is formed by copolymerizing a water-soluble monomer or its precursor with a cross-linking agent and/or polysaccharides in the component A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a water absorbent resin dispersion, and more particularly to a method for producing a water absorbent resin dispersion having a fine dispersed particle size and good dispersion stability.

[0002]

2. Description of the Related Art A plasticizer obtained by mixing a water absorbent resin with a carboxylic acid ester, a phosphoric acid ester, an epoxidized vegetable oil, a chlorinated plasticizer or the like in order to impart water absorption and moisture absorption and release properties to a molded product of polyvinyl chloride resin. It is known to manufacture polyvinyl chloride resin molded articles using.

[0003]

However, a polyvinyl chloride resin molded article using a plasticizer in which a water absorbent resin is mixed with a carboxylic acid ester, a phosphoric acid ester, an epoxidized vegetable oil, a chlorinated plasticizer, etc. The amount of moisture absorption and release is small,
There is also a problem that the water absorption and moisture absorption / desorption speeds are slow. Further, if the amount of the water-absorbent resin added is increased to solve the above problems, there is a problem in that the surface of the formed polyvinyl chloride resin molded product becomes sticky.

[0004]

Means for Solving the Problems The present inventors have made extensive studies on the production of a water-absorbent resin dispersion which is easy to produce, has a fine particle size, and has good dispersion stability. . That is, in the present invention, the water-absorbent resin (B) or its water-absorbent gel is dispersed in one or more plasticizers (A) selected from the group consisting of carboxylic acid esters, phosphoric acid esters, epoxidized vegetable oils and chlorinated plasticizers. The (B)
(A) is a water-absorbent resin dispersion characterized by being formed by polymerizing a water-soluble monomer or its precursor with a crosslinking agent and / or a polysaccharide in (A).

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, one or more plasticizers (A) selected from the group consisting of carboxylic acid esters, phosphoric acid esters, epoxidized vegetable oils, and chlorinated plasticizers are as follows. One of them is USP348.
Those described in Japanese Patent No. 9723 are also included.

Examples of the carboxylic acid ester include phthalic acid ester, aliphatic dibasic acid ester, aliphatic ester, polyester plasticizer and the like.

As phthalic acid esters, dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), diheptyl phthalate (DHP), di-2-ethylhexyl phthalate (DO).
P), di-n-octyl phthalate (DnOP), diisooctyl phthalate (DIOP), diisononyl phthalate (DINP), didecyl phthalate (DDP),
Diisodecyl phthalate (DIDP), C ₈ ~C10 mixed higher alcohols phthalate, butyl benzyl phthalate (BBP), butyl octyl phthalate (BOP) and the like.

Examples of the aliphatic dibasic acid ester include dioctyl adipate, dioctyl azelate, dioctyl sebacate and the like. Further, a polyester plasticizer having an average molecular weight of 1000 to 8000 in which several to ten or more propylene glycol ester units of a dibasic acid such as adipic acid or azelaic acid are linearly linked is also included.

Examples of the fatty acid ester include octyl oleate and octyl stearate. Examples of the phosphoric acid ester include tricresyl phosphate, trixylenyl phosphate, trioctyl phosphate and the like. Epoxidized vegetable oils include soybean oil epoxies. Examples of the ester plasticizer include butylphthalyl butyl glycolate, tributyl citrate and the like. Examples of the chlorinated plasticizer include chlorinated paraffin and chlorinated alkyl stearate.
As these (A), those exemplified above may be used alone or in combination of two or more kinds. Preferred are carboxylic acid esters, and particularly preferred are phthalic acid esters.

As the water-soluble monomer in the present invention, a vinyl monomer having a carboxyl group, a vinyl monomer having a sulfonic acid group, a vinyl monomer having a phosphoric acid group, salts thereof, and a hydroxyl group are used. And vinyl monomers having an ether group and vinyl monomers having an ammonium group.

The vinyl monomer having a carboxyl group includes (meth) acrylic acid, crotonic acid, sorbic acid,
Examples thereof include maleic acid, itaconic acid, cinnamic acid and their acid anhydrides.

Examples of vinyl monomers having a sulfonic acid group include aliphatic or aromatic vinyl sulfonic acids [vinyl sulfonic acid, allyl sulfonic acid, vinyl toluene sulfonic acid, styrene sulfonic acid, etc.]; (meth) acrylic sulfonic acid [ Sulfoethyl (meth) acrylate, sulfopropyl (meth) acrylate, etc.]; (meth) acrylamidesulfonic acid [2-acrylamido-2-methylpropanesulfonic acid, etc.] and the like.

As the vinyl monomer having a phosphoric acid group,
2-hydroxyethyl (meth) acryloyl phosphate, phenyl-2-acryloyloxyethyl phosphate and the like can be mentioned.

These vinyl monomers may be used as salts of the above-mentioned carboxylic acid, sulfonic acid and phosphoric acid. These salts include alkali metal salts (salts such as sodium, potassium and lithium), alkaline earth metal salts (salts such as calcium and magnesium), ammonium salts and amine salts (alkylamine salts such as methylamine and trimethylamine). Alkanolamine salts such as triethanolamine and diethanolamine). Of these, alkali metal salts are preferable, and sodium salts and potassium salts are particularly preferable.

As the vinyl monomer having a hydroxyl group,
Examples thereof include hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate. Examples of vinyl monomers having an ether group include (meth) acrylic acid ethylene glycol monomethyl ether and (meth) acrylic acid trioxyethylene glycol.
Vinyl monomers having an ammonium group include N, N,
Examples thereof include N-trimethyl-N- (meth) acryloyloxyethylammonium chloride and N, N, N-triethyl-N- (meth) acryloyloxyethylammonium chloride.

The precursor of the water-soluble monomer is one which becomes water-soluble by hydrolysis, for example, methyl (meth) acrylate, ethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, acetic acid. Examples include vinyl and (meth) acrylonitrile. As these water-soluble monomers or their precursors, those exemplified above may be used alone or in combination of two or more kinds. Preferred is a vinyl monomer having a carboxyl group.

Of these water-soluble monomers, vinyl monomers having a carboxyl group, vinyl monomers having a sulfonic acid group, and salts thereof are preferable.

In the present invention, other vinyl monomers can be used if necessary. Other vinyl monomers include aromatic vinyl monomers such as styrene, α-methylstyrene, hydroxystyrene and chlorostyrene; unsaturated nitriles such as (meth) acrylonitrile; alkyl groups having 1 to 30 carbon atoms. (Meth) acrylic acid alkyl ester, (meth) acrylic acid ester such as hydroxypolyoxyalkylene ether mono (meth) acrylate; olefins such as ethylene and propylene; perfluorooctylethyl methacrylate, perfluorooctylethyl acrylate, etc. Fluorine-containing vinyl monomers; amino group-containing vinyl monomers such as diaminoethylmethacrylate and morpholinoethylmethacrylate; and vinyl-modified silicone modified at both ends. Among these, aromatic vinyl monomers, unsaturated nitriles and (meth) acrylic acid esters are preferable from the viewpoint of copolymerizability and dispersion stability.

Examples of the crosslinking agent of the present invention include copolymerizable crosslinking agents and other crosslinking agents. The copolymerizable cross-linking agent is a compound having two polymerizable double bonds; and at least one functional group having at least one polymerizable double bond and reactive with the water-soluble monomer. The compound which has an individual is mentioned.

Examples of the compound having two polymerizable double bonds include the following. Bis (meth) acrylamide; N, N-alkylene (c1-c6) bis (meth) acrylamide (for example, N, N-methylenebisacrylamide). Derived from polyesters of polyols or polyepoxides with unsaturated mono- or polycarboxylic acids, such as ethylene glycol, trimethylolpropane, glycerin, polyoxyethylene glycol, polyoxypropylene glycol or cyclohexene diepoxide and (meth) acrylic acid or maleic acid. Ruji
Alternatively, tri- (meth) acrylic acid ester and di- or trimarate. Carbamyl ester: polyisocyanate [tolylene diisocyanate, hexamethylene diisocyanate,
4,4'-diphenylmethane diisocyanate and N
A carbamyl ester obtained by reacting a CO group-containing prepolymer (obtained by reacting the above polyisocyanate with an active hydrogen atom-containing compound) with hydroxyethyl (meth) acrylate. Polyvinyl compound: divinylbenzene, divinyltoluene, divinylxylene, divinylether, divinylketone, trivinylbenzene and the like. Di- or poly- (meth) allyl ether of polyol: Poly (meth) allyl ether of polyols [alkylene glycol, glycerin, polyalkylene glycol, polyalkylene polyol, carbohydrate, etc.] (for example, polyethylene glycol diallyl ether,
Allylated starch and cellulose). Polyallyl ester of polycarboxylic acid: diallyl phthalate, diallyl adipate, etc. Ester of unsaturated mono- or polycarboxylic acid and mono (meth) allyl etherified polyol: (meth) acrylic acid ester of polyethylene glycol monoallyl ether, etc. Polyallyloxyalkanes: tetraallyloxyethane and the like.

Having at least one polymerizable double bond,
And at least one functional group reactive with the water-soluble monomer.
In the compound having a group, a carboxyl group in the water-soluble monomer, a sulfonic acid group, a phosphoric acid group, a group that reacts with a hydroxyl group or an ammonium base, a hydroxyl group,
An epoxy group and a tertiary amine group are mentioned. Examples of the compound include a hydroxyl group-containing ethylenically unsaturated compound [eg, N-methylol (meth) acrylamide, etc.];
Epoxy group-containing ethylenically unsaturated compound [eg, glycidyl (meth) acrylate, etc.]; Tertiary amino group-containing ethylenically unsaturated compound [eg, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, etc.] And so on. Other cross-linking agents include polyvalent metal salts such as calcium oxide and zinc diacetate. Among these crosslinking agents, copolymerizable crosslinking agents are preferable, and N, N-methylenebisacrylamide, ethylene glycol diacrylate, trimethylolpropane triacrylate and tetraallyloxyethane are particularly preferable.

Examples of the polysaccharide of the present invention include starch and cellulose. Examples of the starch include raw starch such as sweet potato starch, potato starch, wheat starch, corn starch, and rice starch;
Modified starches such as oxidized starch, dialdehyde starch, alkyl etherified starch, aryl etherified starch, oxyalkylated starch, aminoethyl etherified starch and the like can be mentioned. As cellulose,
Examples thereof include cellulose obtained from wood, leaves, stems, skins, seed hairs, and the like; processed celluloses such as alkyl etherified cellulose, organic acid esterified cellulose, oxidized cellulose, and hydroxyalkyl etherified cellulose.

The dispersion of the present invention can be obtained by the following method. The water-soluble monomer or its precursor is abbreviated as (1), the other vinyl monomer is abbreviated as (1 ′), and the crosslinking agent and / or the polysaccharide is abbreviated as (2). To the aqueous solution or dispersion of (1), (2) and optionally (1 ′), a solution obtained by mixing (A) and optionally an emulsifier is added dropwise, and if necessary, heated by using a radical polymerization catalyst or radiation. , Electron beam, ultraviolet rays, etc. The aqueous solution or dispersion of (1), (2) and (1 ′) is added dropwise to (A), and a radical polymerization catalyst and an emulsifier are used if necessary, and the same operation is performed thereafter. To the mixture of (A) and water, the aqueous solution or aqueous dispersion of (1), (2) and, if necessary, (1 ') is added dropwise, and if necessary, a radical polymerization catalyst and an emulsifier are used, and the same operation is performed thereafter. If necessary, a radical polymerization catalyst is allowed to exist in a dispersion liquid comprising (A), an emulsifier and water, (1), (2) and (1 ′) are added dropwise, and the same operation is performed thereafter.

(1), (2) and optionally (1 ')
Is usually 2 to 120% based on the weight of (A),
Preferably 10 to 100%, more preferably 30 to 9
0%.

The amount of (1) used is usually 50% or more, preferably 60 to 99.9%, particularly preferably 75, based on the total weight of (1), (2) and optionally (1 ').
~ 95%.

The amount of (2) used is usually 0.00 based on the total weight of (1), (2) and optionally (1 ').
It is 1% to 20%, preferably 0.01 to 10%, particularly preferably 0.1 to 5%. The usage of (2) is 0.0
If it is less than 01% or more than 20%, the water absorption capacity becomes insufficient.

The amount of other vinyl monomer (1 ') used is
It is usually 0 to 20%, preferably 0 to 10%, more preferably 0 to 5% based on the total weight of (1), (2) and, if necessary, (1 ').

The amount of water used is 5 based on the weight of the dispersion.
It is necessary to be -50%, preferably 5-45.
%, And more preferably 10 to 30%. If the amount of water used exceeds 50% or less than 5%, it is difficult to produce a dispersion.

As the radical polymerization catalyst, azo compounds [azobisisobutyronitrile, azobiscyanovaleric acid, 2,2'-azobis (2-aminodipropane) dihydrochloride, etc.], inorganic peroxides [hydrogen peroxide] ,
Ammonium persulfate, potassium persulfate, sodium persulfate, etc.], organic peroxides [benzoyl peroxide, di-t-
Butyl peroxide, cumene peroxide,
Succinic acid peroxide, di (2-ethoxyethyl) peroxydicarbonate, etc.]; redox catalyst [reducing agent such as alkali metal sulfite or bisulfite, ammonium sulfite, ammonium bisulfite, and ascorbic acid, and alkali metal persulfate] A combination of oxidizing agents such as salt, ammonium persulfate and peroxide]; and a combination of two or more of these. The amount of the catalyst used is usually 0.0005 to 5%, preferably 0.001 to 2%, based on the total weight of (1), (2) and, if necessary, (1 ′).

As the emulsifier, a nonionic surfactant [lauryl alcohol ethylene oxide adduct, lauric acid ethylene oxide adduct, sorbitan lauric acid monoester, stearylamine ethylene oxide adduct, nonylphenol ethylene oxide adduct, etc.]; anion Cationic surfactants [lauryl alcohol sulfate, sodium alkylbenzene sulfonate, aerosol OT, dithiophosphoric acid ester salt, etc.]; cationic surfactants [lauryl amine acetate, triethanol amine monostearate formate, etc.]; and these Two or more types can be used in combination. Preferred are nonionic surfactants. The amount of the emulsifier used is usually 0 to 20% by weight, preferably 0.1 to 10% by weight, based on the dispersion.

The dispersed particle size of the particles in the dispersion of the present invention is
Usually 0.01 to 100 μm, preferably 0.05 to 10
μm, particularly preferably 0.1 to 5 μm. If the dispersed particle size exceeds 100 μm, the stability of the dispersion becomes poor, and if it is less than 0.01 μm, problems such as particle aggregation occur.

In the present invention, the ratio of (B) to the total weight of (A) and (B) is usually 1 to 70%, preferably 5 to 65%, particularly preferably 20 to 60%. When the content of the vinyl polymer chain exceeds 70%, aggregation tends to occur and the dispersibility becomes unstable. The content of (A) is usually 30 to 99%, preferably 35 to 95%, based on the weight of the dispersion,
Particularly preferably, it is 40 to 80%. (A) content is 3
If it is less than 0, the particles are aggregated and the dispersibility becomes unstable.

The dispersion of the present invention can be applied to the production of a molded product of polyvinyl chloride resin which absorbs water and absorbs moisture. Water-absorbing, moisture-absorbing and desorbing polyvinyl chloride resin molded products are obtained by removing the water of the dispersion of the present invention as necessary, and then polyvinyl chloride resin, plasticizers, stabilizers, fillers if necessary, coloring agents if necessary, and foaming. It is obtained by a known method such as a calender molding method, an extrusion molding method, an injection molding method or the like after mixing with an agent or the like to give a vinyl chloride compound.

As the vinyl chloride resin, those conventionally used for the production of vinyl chloride resin molded products can be used. As such a polyvinyl chloride resin, for example, in the case of a straight resin, those having a degree of polymerization of 800 to 1500, vinyl ethers, acrylic esters, copolymers with ethylene or vinyl acetate, and the like can be mentioned.

As the stabilizer, a lead-based stabilizer, a metal soap,
Examples thereof include an organic tin stabilizer, a chelating agent, an antioxidant, an ultraviolet absorber and a lubricant such as wax. Examples of the filler include calcium carbonate, clay, colloidal silica and the like. Examples of the colorant include titanium oxide and the like. Examples of the foaming agent include azodicarbozamide, azobisisobutyronitrile, 4,4′oxybisbenzenesulfonyl hydrazide and the like.

[0036]

The present invention will be further described with reference to the following examples, but the present invention is not limited to these examples. Parts in the examples are parts by weight. The raw materials used in Examples 1 to 3 are as follows. Plasticizer (A): di-2-ethylhexyl phthalate (D
OP: Mitsubishi Gas Chemical Co., Ltd. Plasticizer A1: Dibutyl phthalate (DBP: Mitsubishi Gas Chemical Co., Ltd.) Plasticizer A2: Diisononyl phthalate (DINP: Mitsubishi Gas Chemical Co., Ltd.) Vinyl Monomer (1 ): Acrylic acid (manufactured by Nippon Shokubai Kagaku) Copolymerizable cross-linking agent (2): Methylenebisacrylamide (manufactured by Nitto Kagaku Kogyo Co., Ltd.) Radical polymerization catalyst: 2,2′-azobis (2,4-dimethylvaleronitrile) (V-65: Wako Pure Chemical Industries, Ltd.
Emulsifier: sorbitan lauric acid monoester (Ionet S-20: Sanyo Kasei Co., Ltd.)

[Volume-Based Particle Diameter Measuring Method] The water-absorbent resin dispersion is diluted with the phthalic acid ester used in the water-absorbent resin dispersion so that the laser light transmittance becomes 70 to 90%, and the particle size distribution is obtained. The particle diameter was measured with a measuring device (laser diffraction / scattering type particle size distribution measuring device LA-700; manufactured by Horiba Ltd.). The obtained particle size is shown in Table 2. The value of the particle size in Table 2 shows the particle size corresponding to 50% of the cumulative distribution of the volume-based particle size distribution.

[Evaluation Method for Moisture Absorption and Desorption] The polyvinyl chloride foam and the film were allowed to stand in a thermo-hygrostat having a relative humidity of 90 RH% (25 ° C.), and the time change of water absorption was measured.
Then, it was left to stand in a thermo-hygrostat having a relative humidity of 40 RH% (25 ° C.), and the water discharge amount was measured. The amount of water absorbed and the amount of water discharged are
The amount (g) of water absorbed or discharged per 1 m ^{2 of} foam and film is shown.

The absorption amount and absorption rate of ion-exchanged water were measured by the following methods. [Absorbing amount] 1 g of the absorbing member is put in a 250 mesh nylon net tea bag, soaked in a large excess of 0.9% physiological saline for 1 hour for absorption, and then pulled up to 15
Drain for minutes and measure the weight gain. This value was taken as the absorption amount. [Absorption rate] 1 g of the absorbent member was placed in a 250-mesh nylon net tea bag, immersed in a large excess of physiological saline for 2 minutes, then pulled up and drained for 15 minutes to measure the increased weight. This value was taken as the absorption rate.

Examples 1 to 3 In a 1 L four-necked flask equipped with a temperature controller, a vacuum stirring blade, a nitrogen inlet and outlet, at 40 ° C. or lower,
Table 1 shows water, sodium hydroxide, vinyl monomer (1), copolymerizable cross-linking agent (2), radical polymerization catalyst and emulsifier.
The amounts used were as described in. After that, the amount of phthalate ester used in Table 1 was gradually added under stirring to prepare a W / O type emulsion, and then the vinyl monomer (1) was polymerized under stirring at 50 to 80 ° C. to absorb water. Resin dispersion (D1-
D3) was synthesized.

Example 4 In a 1-liter four-necked flask equipped with a temperature controller, a vacuum stirring blade, a nitrogen inflow and an outflow port, a temperature of 40 ° C. or lower was set to 25.
% Aqueous sodium hydroxide solution (350 parts) and vinyl monomer (1) (200 parts) with stirring and mixing, and then copolymerizable crosslinking agent (2)
Further, 0.02 part was added and mixed by stirring to obtain a uniform solution (). In a 2 L Erlenmeyer flask, 400 parts of phthalic acid ester (A) and 4 parts of an emulsifier (“Emalmin 140” manufactured by Sanyo Chemical Industry Co., Ltd.) were mixed and stirred to form a uniform solution (). Then, while stirring the solution () at 40 ° C. or lower in a nitrogen liquid while stirring, the solution () was continuously charged for 1 hour to prepare a W / O type emulsion.
Furthermore, a solution prepared by dissolving 0.02 part of a radical polymerization catalyst (“ADVN” manufactured by Otsuka Chemical Co., Ltd.) in 0.1 part of toluene in advance was added, and the mixture was heated to 50 ° C. with stirring to give a water absorbent resin dispersion (D4). Synthesized.

Example 5 In Example 4, the vinyl monomer was added to 2-acrylamide-
A water absorbent resin dispersion (D5) was synthesized in the same manner as in Example 4 except that 2-methylpropanesulfonic acid was used.

Dispersions D1 to D5 obtained in Examples 1 to 5
Table 2 shows the particle diameters and viscosities of.

[0044]

[Table 1]

[0045]

[Table 2]

The raw materials used in Use Examples 1 to 5 and Comparative Use Examples 1 to 5 are as follows. Plasticizer (A): di-2-ethylhexyl phthalate Plasticizer A3: tricresyl phosphate Plasticizer A4: di-n-octyl phthalate Paste PVC: Zeon 131C (Nippon Zeon Co., Ltd.)
Calcium carbonate: Escalon # 2000 (manufactured by Sankyo Flour Milling Co., Ltd.) Titanium oxide: CR-90 (manufactured by Ishihara Sangyo Co., Ltd.) Stabilizer: Mg-Zn stabilizer (MARK OF-30:
Asahi Denka Kogyo Co., Ltd. Foaming agent: Azodicarbosoamide (Vinihol AC: Nagawa Kasei Kogyo Co., Ltd.) Water absorbent resin: Acrylic graft of starch (Sunfresh ST-500TM: Sanyo Kasei Co., Ltd.) Made)

Use Examples 1 to 3 The dispersions, plasticizers, paste resins, calcium carbonate, titanium oxide, stabilizers and foaming agents obtained in Examples 1 to 5 were mixed in the amounts shown in Table 3, and a release paper was prepared. Apply 100μm thick with a bar coater and heat at 150 ° C for 30 minutes.
Polyvinyl chloride foams F1 to F3 were prepared by heating for 1 minute at ℃. Table 4 shows the foam properties (foam density, water absorption performance, moisture absorption / release performance) of the obtained polyvinyl chloride foam.

Use Examples 4 and 5 The dispersions obtained in Examples 1 to 5, the plasticizer, the paste resin, the calcium carbonate, the titanium oxide and the stabilizer were mixed in the amounts shown in Table 3 and the bar was placed on the release paper. Thickness 100μ with coater
m, and was heated at 150 ° C. for 30 minutes to prepare polyvinyl chloride films F4 and F5. About the film characteristics (moisture absorption / release performance) of the obtained polyvinyl chloride foam Table 5
Shown in

Comparative Use Examples 1 to 3 Polyvinyl chloride foam F6 of Comparative Use Examples 1 to 3 was prepared by using the components shown in Table 3 in the same manner as in Use Examples 1 to 3.
~ F8 was created. Foam characteristics of the obtained polyvinyl chloride foam (foam density, water absorption performance, moisture absorption / release performance)
Is shown in Table 4.

Comparative Use Examples 4 and 5 Polyvinyl chloride films F9 and F10 were prepared in the same manner as Use Examples 4 and 5 with the amounts shown in Table 3. Table 5 shows the film characteristics (moisture absorbing / releasing performance) of the obtained polyvinyl chloride film.

[0051]

[Table 3]

[0052]

[Table 4]

[0053]

[Table 5]

As shown in Tables 4 and 5, by using the water-absorbent dispersion according to the present invention, water absorption and moisture absorption / release properties of the polyvinyl chloride foam and the film can be greatly improved.

[0055]

INDUSTRIAL APPLICABILITY The water-absorbent resin dispersion of the present invention has the water-absorbent resin uniformly dispersed as fine particles of 100 μm or less, and has excellent dispersion stability. Furthermore, when the dispersion of the present invention is applied to the production of a polyvinyl chloride resin molded article,
It is possible to obtain a molded product of polyvinyl chloride resin that absorbs and absorbs water and moisture, and the resulting molded product exhibits excellent water absorption and moisture absorption and desorption capacity (water absorption amount, water absorption rate, moisture absorption and desorption rate). From the above effects, a water-absorbent resin dispersion obtained by the present invention and a polyvinyl chloride resin molded article using the same,
It is extremely useful in applications such as freshness-maintaining materials for fruits and vegetables, drip absorbents, moisture or humidity regulators, moisture absorbing / releasing wallpaper, leather for automobiles, and vinyl films for agriculture.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location C08K 5/521 KCB C08K 5/521 KCB C08L 27/06 LFR C08L 27/06 LFR 33/02 LHR 33/02 LHR 43/02 LKA 43/02 LKA 57/04 LMK 57/04 LMK 91/00 LSJ 91/00 LSJ // C08F 2/44 MCR C08F 2/44 MCR

Claims (7)

[Claims] 1. A carboxylic acid ester, a phosphoric acid ester,
The water-absorbent resin (B) or its water-absorbent gel is dispersed in one or more plasticizers (A) selected from the group of epoxidized vegetable oils and chlorinated plasticizers, and the water-absorbent resin (B) is contained in (A). A water-absorbent resin dispersion, wherein the water-soluble monomer or its precursor is polymerized with a cross-linking agent and / or a polysaccharide to be formed. 2. The dispersion according to claim 1, wherein the ratio of (B) to the total weight of (A) and (B) is 1 to 70%. 3. The dispersion according to claim 1, wherein (B) or its water-absorbent gel dispersed in (A) has an average particle size of 0.01 to 100 μm. 4. One or more vinyl monomers having a carboxyl group or a sulfonic acid group in the presence of water in (A),
The dispersion according to any one of claims 1 to 3, wherein (B) formed by polymerization of a copolymerizable cross-linking agent and optionally other vinyl monomer or its water-absorbing gel is dispersed in (A). . 5. When forming (B) or its water-absorbing gel,
The dispersion according to claim 4, wherein the amount of water to be present is 5 to 50% by weight based on the total weight of (A), (B) and water. 6. Polymerization in the presence of an emulsifier with water (B)
Alternatively, the dispersion according to claim 4 or 5, which forms a water-absorbing gel thereof. 7. A resin composition comprising the dispersion according to any one of claims 1 to 6 and a vinyl chloride resin.