JPH04298516A - Water-swellable composite resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition which can give a molding improved in the tendency to release a water-containing gel upon absorption of water by using a polymer prepared by synthesizing a water-absorptive resin in a urethane resin and/or a polymer prepared by synthesizing a urethane resin in a dispersion of a water-absorptive resin. CONSTITUTION:A polymer (A) is obtained by polymerizing a mixture of a hydrophilic monomer with a cross-linking agent, a catalyst and optionally starch or a cellulose derivative in a urethane resin or its solution or dispersion at 30-160 deg.C for 1-20hr. Another polymer (B) is obtained by reacting an active hydrogen compound with an organic polyisocyanate in a nonaqueous water-absorptive resin dispersion obtained by dispersing water-absorptive resin particles in a nonaqueous solvent. The title composition comprising the urethane resin and the water-absorptive resin is from polymers A and/or B.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-swellable composite resin composition.

0002

[Prior Art] Conventionally, a composite resin composition of a urethane resin and a water-absorbing resin has been produced by separately producing the urethane resin and the water-absorbing resin in advance, pulverizing the water-absorbing resin, and then mixing and dispersing it in the urethane resin. What you get is known.

0003

[Problems to be Solved by the Invention] However, the conventional products have a problem in that the dispersion state of each resin component during mixing is not sufficient, so that the hydrous gel detachment property when water is absorbed is large.

0004

[Means for Solving the Problems] The present inventors have arrived at the present invention as a result of intensive studies aimed at obtaining a composite resin composition of a urethane resin and a water-absorbing resin that has improved hydrogel release properties when a molded product absorbs water. did. That is, the present invention is a water-swellable composite resin composition characterized by comprising the following polymer (1) and/or polymer (2). Polymer (1): A polymer formed from a mixture of a urethane resin, a hydrophilic monomer, a crosslinking agent, a catalyst, and, if necessary, starch and/or a cellulose derivative. Polymer (2): A polymer formed from a mixture of a nonaqueous dispersion of a water-absorbing resin, an active hydrogen-containing compound, and an organic polyisocyanate.

The urethane resin used in the polymer (1) of the present invention includes those obtained by reacting an active hydrogen-containing compound and an organic polyisocyanate in any proportion. Examples of active hydrogen compounds include polyols (high molecular polyols and low molecular polyols) and polyamines.

[0006] Examples of the polymer polyol include polyether polyols and polyester polyols. Examples of polyether polyols include low-molecular polyols (ethylene glycol, propylene glycol, 1,3-
Butylene glycol, 1,4 butanediol, 1,6-
Bifunctional polyols such as hexanediol, neopentyl glycol, diethylene glycol, cyclohexylene glycol; trifunctional or higher functional polyols such as glycerin, trimethylolpropane, pentaerythritol, methyl glucoside, sorbitol, saccharose, xylit, mannitol, glucose, fructose, etc. ),
Polyhydric phenols (bisphenols such as bisphenol A), and/or amines (alkanolamines such as triethanolamine, N-methyldiethanolamine; aliphatic polyamines such as ethylenediamine, diethylenetriamine; aromatic diamines such as tolylenediamine, diphenylmethanediamine, etc.) ) alkylene oxide [one or more alkylene oxides having 2 to 4 carbon atoms, such as ethylene oxide, propylene oxide, butylene oxide, etc. (random and/or block)] adducts, ring-opening polymers of alkylene oxides (of tetrahydrofuran) Examples include ring-opening polymerization, polytetramethylene ether glycol by hydrolysis, etc.).

The above-mentioned polyester polyols include polycarboxylic acids (aliphatic polycarboxylic acids such as adipic acid, succinic acid, sebacic acid, azelaic acid, fumaric acid, maleic acid, dimerized linoleic acid; aromatic polycarboxylic acids such as phthalic acid). , isophthalic acid and terephthalic acid) and low-molecular polyols or polyether polyols (the above-mentioned low-molecular polyols, triethylene glycol to polyethylene glycol, etc.), polyester polyols with hydroxyl groups at the ends, lactone polyesters (polycaprolactone diol, etc.), polycarbonates Other examples include polybutadiene diol, hydrogenated polybutadiene polyol, acrylic polyol, and polymer polyol [polyol made by polymerizing a vinyl monomer (acrylonitrile, styrene, etc.) in a polyol (the above-mentioned polyether, polyester, etc.)]. It will be done.

Two or more types of the above-mentioned polymeric polyols can also be used in combination. Among these, preferred are polyether polyols and polyester polyols. The OH equivalent of polymer polyol is usually 200 to 2,500
, preferably 250 to 1,500.

[0009] Examples of low-molecular polyols include those similar to the low-molecular polyols explained in the section on polyether polyols, and compounds containing ionic groups or ion-forming groups. Among the ionic groups, anionic groups or anion-forming groups are preferred, and specific examples include hydroxycarboxylic acids (glyceric acid, glycolic acid, 2,6-dioxybenzoic acid, dimethylolpropionic acid, etc.), hydroxysulfonic acid [2 -hydroxyethanesulfonic acid,
phenolsulfonic acid, naphtholsulfonic acid isomers, 3-(2,3-dihydroxypropoxy)-1-propanesulfonic acid sodium salt, etc.), aminocarboxylic acids (glycine, 6-aminocaproic acid, mono- and di-
aminobenzoic acid, etc.), aminosulfonic acids (amidesulfonic acid, hydrazine-disulfonic acid, taurine, etc.),
Examples include esters of phosphoric acid [bis-(α-hydroxyisopropyl)-phosphinic acid, phosphorous acid-bis-glycol ester, phosphoric acid-bis-propylene glycol ester, etc.]. Examples of the base that converts an anion-forming group into an anionic group include inorganic salts (eg, sodium hydroxide, potassium hydroxide, etc.) and organic bases (eg, trimethylamine, triethylamine, tributylamine, diethanolamine, etc.). Preferred low-molecular polyols include ethylene glycol, 1,4-butanediol, and compounds containing anionic groups or anion-forming groups.

Examples of polyamines include aliphatic polyamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, diethylene triamine, etc.), alicyclic polyamines [4,4'-diaminodicyclohexylmethane (hydrogenated MBA), 1,4-diaminocyclohexane, 4
, 4'-diamino-3,3'-dimethylcyclohexylmethane, isophorone diamine, etc.], aliphatic diamines with aromatic rings (xylylene diamine, etc.), aromatic polyamines (diphenylmethane diamine, dichlorodiphenylmethane diamine, tolylene diamine, diethyl tolylene diamine, benzidine, phenylene diamine, etc.),
Alkanolamines (mono- or di-ethanolamine, propanolamine, N-hydroxyethylenediamine, etc.), polyalkylene oxide polyamines [alkylene oxides having 2 to 4 carbon atoms of the active hydrogen-containing compounds, such as ethylene oxide, propylene oxide, butylene oxide, etc.] One or more adducts (random and/or block), ring-opening polymers of alkylene oxides (ring-opening polymers of tetrahydrofuran, polytetramethylene ether glycol by hydrolysis, etc.)
Compounds having a structure in which the terminal OH group of a polyether polyol is substituted with an amino group, such as polyoxyethylene ether diamine and polyoxypropylene ether diamine], and mixtures of two or more of these may be mentioned. Preferred among the polyamines are hexamethylene diamine, isophorone diamine and 4,4'-diaminodicyclohexylmethane.

These active hydrogen compounds are used alone or in combination with a high molecular polyol and a low molecular polyol and/or a polyamine. The weight ratio of high molecular polyol and (low molecular polyol and/or polyamine) is 1:0 to 1:3, preferably 1:0.0
The ratio is 5 to 1:1.5. The average active hydrogen (OH, NH2, NH) equivalent of the active hydrogen-containing compound (whole) is usually 75-
1,500, preferably 100-750. The average number of functional groups of the active hydrogen-containing compound is usually 2 to 3, preferably 2 to 2.5.

[0012] Examples of the organic polyisocyanate include ethylene diisocyanate, tetramethylene diisocyanate,
Hexamethylene isocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexane diisocyanate, lysine diisocyanate, 2,6-diisocyanate methyl caproate, bis(2-isocyanate ethyl ) fumarate, bis(2-isocyanatoethyl)carbonate, 2-isocyanateethyl-2
, 6-diisocyanate hexanoate; isophorone diisocyanate (IPDI), dicyclohexylmethane isocyanate (hydrogenated MDI), cyclohexylene diisocyanate, netyl cyclohexylene diisocyanate (hydrogenated TDI), bis(2-ethyl isocyanate)
4-Cyclohexene-1,2-dicarboxylate; xylylene diisocyanate, diethylbenzene diisocyanate; water-modified HDI, trimerized IPDI; tolylene diisocyanate (TDI), crude TDI, diphenylmethane diisocyanate (MDI), polyphenyl Methane polyisocyanate (PAPI; crude MDI
), naphthylene diisocyanate and modified products of these polyisocyanates (containing carbodiimide groups, uretdione groups, uretoimine groups, urea groups, biuret groups and/or isocyanurate groups), such as carbodiimide-modified MDI; and mixtures of two or more of these. can be given. Among these, preferred are HDI, I
They are PDI, hydrogenated MDI, TDI and MDI.

Examples of organic solvents in the organic solvent solution of urethane resin include ketone solvents (acetone, methyl ethyl ketone, methyl propylene ketone, etc.), ester solvents (methyl formate, ethyl formate, methyl acetate, propyl acetate, etc.), and hydrocarbon solvents. (pentane, n-hexane, cyclohexane, benzene, toluene, xylene, etc.), ether solvents (isopropyl ether, dioxolane,
dioxane, etc.), alcoholic solvents (methanol, ethanol, propanol, butanol, etc.), chlorinated solvents (chloroform, trichloroethane, trichloropropane, carbon tetrachloride, trichlorethylene, tetrachlorethylene, etc.), and mixtures of two or more of these. can give.

[0014] The production of urethane resins can be roughly divided into two methods: a method in which an active hydrogen-containing compound and an organic polyisocyanate are reacted at once, and a method in which the reaction is carried out stepwise. The latter method involves (1) reacting a portion of the active hydrogen-containing compound (for example, a high molecular weight polyol) with an organic polyisocyanate to form an NCO-terminated prepolymer;
or polyamine), ① Reacting an active hydrogen-containing compound with a part of the organic polyisocyanate to form a prepolymer with active hydrogen group terminals (OH, NH2, NH, etc.), and then the remainder of the organic polyisocyanate. There are two methods: one is a method of manufacturing by reacting the other, and a method is a combination of these methods. When an anion-forming group reacts with a base to form an anion group, it can be converted into an anion group by neutralizing with a base before, during or after the urethanization reaction.

[0015] The urethane formation reaction is usually carried out at room temperature to 140°C.
, preferably at 60 to 120°C (however, when reacting polyamines, the temperature is usually 80°C or lower, preferably 0 to 120°C).
(carried out at a temperature of 70°C). The reaction is usually carried out in the presence of an organic solvent, but the organic solvent may be added during or after the reaction.

The concentration of the organic solvent solution of the urethane resin thus obtained is usually 5 to 70%, preferably 10 to 6%.
It is 0%. The viscosity is usually 50 to 1,000,000 (c
ps/25°C).

Any hydrophilic monomer may be used as long as it has an ionic group, an ion-forming group or a nonionic polar group and is highly soluble in water. For example, anionic vinyl monomers, cationic vinyl monomers, etc. monomers, nonionic water-soluble vinyl monomers, and mixtures thereof. Any anionic vinyl monomer may be used as long as it exhibits anionic properties, but vinyl monomers having a carboxyl group and/or sulfone group, anhydrides thereof, and salts thereof are preferred. It will be done.

As the anionic vinyl monomer having a carboxyl group, unsaturated mono- or polycarboxylic acids [(
meth)acrylic acid, crotonic acid, sorbic acid, maleic acid, itaconic acid, cinnamic acid, etc.], their anhydrides [maleic anhydride, etc.], and their salts [alkali metal salts (salts of sodium, potassium, lithium, etc.) ), alkaline earth metal salts (salts of calcium, magnesium, etc.),
Ammonium salts and amine salts (salts of alkylamines such as methylamine and trimethylamine; salts of alkanolamines such as triethanolamine and diethanolamine)] and mixtures of two or more of the above monomers are included. Among these, preferred are alkali metal salts of (meth)acrylic acid.

Examples of the anionic vinyl monomer having a sulfonic group, anhydride or salt thereof include aliphatic or aromatic vinylsulfonic acids [vinylsulfonic acid, allylsulfonic acid, vinyltoluenesulfonic acid, styrenesulfonic acid, etc.]; (meth)acrylic sulfonic acid [sulfoethyl (meth)acrylate, sulfopropyl (meth)acrylate, etc.], (meth)acrylamide sulfonic acid [2-acrylamido-2-methylpropanesulfonic acid, etc.], and their salts [alkali Metal salts (salts of sodium, potassium, lithium, etc.), alkaline earth metal salts (salts of calcium, magnesium, etc.), ammonium salts and amine salts (salts of alkylamines such as methylamine, trimethylamine; triethanolamine, diethanolamine, etc.) (alkanolamine salts, etc.)] and mixtures of two or more of the above monomers. Preferred among these are alkali metal salts of (meth)acrylamide sulfonic acid.

The cationic vinyl monomer may be any one that exhibits cationic properties, but preferably one that has a quaternary ammonium base. Examples of cationic vinyl monomers having a quaternary ammonium base include reaction products of dialkylaminoalkyl (meth)acrylates with alkyl halides or dialkyl sulfates [for example, (meth)acryloyloxyethyl trimethylammonium chloride or bromide, (meth) Acryloyloxyethyltrimethylammonium methosulfate, (meth)acryloyloxyethyldimethylethylammonium chloride, (meth)acryloyloxyethyldiethylmethylammonium chloride,
(meth)acryloyloxyethyldimethylbenzylammonium chloride, (meth)acryloyloxypropyltrimethylammonium chloride, (meth)acryloyloxypropyltrimethylammonium methosulfate, etc.]; combination of dialkylaminohydroxyalkyl (meth)acrylate with alkyl halide or dialkyl sulfate Reactants [such as (meth)acryloyloxyhydroxyethyltrimethylammonium chloride or bromide, (meth)acryloyloxyhydroxyethyltrimethylammonium methosulfate, (meth)acryloyloxyhydroxypropyltrimethylammonium chloride, etc.]; dialkylaminoalkyl (meth)acrylamide and Reactants with alkyl halides or dialkyl sulfates [e.g. chloride or bromide of trimethylaminoethyl (meth)acrylamide, chloride of trimethylaminopropyl (meth)acrylamide, chloride of diethylmethylaminopropyl (meth)acrylamide, etc.]; dialkyl Reaction products of aminohydroxyalkyl (meth)acrylamides with alkyl halides or dialkyl sulfates [e.g. chloride of trimethylaminohydroxyethyl (meth)acrylamide, chloride of trimethylaminohydroxypropyl (meth)acrylamide, diethylmethylaminohydroxypropyl (meth)acrylamide, ) Acrylamide chloride, etc.]
; N-alkylvinylpyridinium halides [e.g. N-methyl-2-vinylpyridinium chloride or bromide, N-methyl-4-vinylpyridinium chloride, etc.], trialkylallylammonium halides [e.g. trimethylallylammonium chloride or bromide, triethylallylammonium chloride, etc.] and mixtures of two or more of these. Among these, dialkylamino (
It is a reaction product of meth)acrylate and alkyl halide.

[0021] As the nonionic water-soluble vinyl monomer,
Examples include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, (meth)acrylamide, and vinylpyrrolidone.

As the crosslinking agent, a compound (1) having at least two polymerizable double bonds and a cationic vinyl monomer and/or anionic vinyl monomer having one polymerizable double bond are used. The compound (2) includes at least one group other than a double bond that can react with a functional group of the body.

Examples of the compound (1) include the following. ■Bis(meth)acrylamide: N,N-alkylene (C1-C6) bis(meth)acrylamide such as N,. N-methylenebisacrylamide. ■Di- or polyester of polyols and unsaturated mono- or polycarboxylic acids: di- or tri-(meth)acrylic of polyols [ethylene glycol, trimethylolpropane, glycerin, polyoxyethylene glycol, polyoxypropylene glycol, etc.] Acid esters: unsaturated polyesters [obtained by the reaction of the above polyols with unsaturated acids such as maleic acid] and di- or tri-(meth)acrylic esters [obtained by the reaction of polyepoxides with (meth)acrylic acid]. "I'll be able to do it" etc. ■Carbamyl ester: polyisocyanate [tolylene diisocyanate, hexamethylene diisocyanate, 4,
4'-diphenylmethane diisocyanate and NCO
carbamyl ester obtained by reacting a group-containing prepolymer (obtained by the reaction of the above-mentioned polyisocyanate with an active hydrogen atom-containing compound, etc.) with hydroxyethyl (meth)acrylate. ■Di- or polyvinyl compounds: divinylbenzene, divinyltoluene, divinylxylene, divinyl ether, divinyl ketone, trivinylbenzene, etc. ■ Di- or poly(meth)allyl ether of polyols: Di- or poly(meth)allyl ether of polyols [alkylene glycol, glycerin, polyalkylene glycol, polyalkylene polyol, carbohydrates, etc.]
or poly-(meth)allyl ethers such as polyethylene glycol diallyl ether and allylated starches, allylated celluloses. ■Di- or poly-allyl ester of polycarboxylic acid: diallyl phthalate, diallyl adipate, etc. ■Esters of unsaturated mono- or polycarboxylic acids and mono(meth)allyl ethers of polyols: (meth)acrylic acid esters of polyethylene glycol monoallyl ether, etc. ■Polyaryloxyalkanes: tetraallyloxyethane, etc.

Examples of the compound (2) include ethylenically unsaturated compounds having a carboxyl group, a sulfone group and/or a group reactive with a quaternary ammonium base, such as a hydroxyl group, an epoxy group, a tertiary amino group, etc. It will be done. Specifically, hydroxyl group-containing unsaturated compounds [N
-methylol (meth)acrylamide, etc.] and epoxy group-containing unsaturated compounds [glycidyl (meth)acrylate, etc.] and tertiary amino group-containing unsaturated compounds [(
dimethylaminoethyl meth)acrylate, diethylaminoethyl (meth)acrylate, etc.).

Among these crosslinking agents, preferred are (
Particularly preferred compounds of 1) are N,N-methylenebisacrylamide, ethylene glycol diacrylate, trimethylolpropane triacrylate and tetraallyloxyethane. The amount of crosslinking agent is usually 0.01 to 10% by weight, preferably 0.1 to 5% by weight, based on the weight of the hydrophilic monomer.

Examples of starch or cellulose derivatives include starch or cellulose esters (acetylcellulose, cellulose butyrate, nitrocellulose, cellulose phosphate, etc.) and cellulose ethers (methylcellulose, ethylcellulose, carboxymethylcellulose, carboxyethylcellulose, etc.). Preferred is starch.

Specific examples of the water-absorbing resin used in the polymer (2) of the present invention include (meth)acrylic acid (salt) polymer, starch/acrylic acid (salt) graft copolymer, and starch/acrylic acid (salt) graft copolymer. Saponified products of acrylic acid ester graft copolymer, saponified products of starch/methyl methacrylate graft copolymer, saponified products of methyl (meth)acrylate/vinyl acetate copolymer, saponified products of starch/acrylonitrile graft copolymer , saponified products of starch/acrylamide graft copolymer, saponified products of starch/acrylonitrile/2-acrylamide/2-methylpropanesulfonic acid graft copolymer, saponified product of starch/acrylonitrile/vinylsulfonic acid graft copolymer, etc. Examples include crosslinked products of each polymer, polyethylene oxide crosslinked with acrylic acid, and crosslinked products of sodium carboxymethyl cellulose. In addition, the above-mentioned (meth)acrylic acid (salt) polymer (including copolymer) is a (meth)acrylic acid (salt) containing maleic acid (salt) in an amount within a range that does not deteriorate the performance of the water-absorbent resin produced. , itaconic acid (salt), (meth)acrylamide, 2-acrylamide, 2-methylpropanesulfonic acid, 2-(meth)acryloylethanesulfonic acid, 2-hydroxyethyl (meth)acrylate, 2-
A copolymer obtained by copolymerizing a comonomer such as vinylpyridine or 4-vinylpyridine may also be used. Crosslinked products of these polymers can be made into crosslinked products by various means. The crosslinking means include, for example, entanglement of molecular chains due to high polymerization of polymer molecules, or self-crosslinking due to pseudo crosslinking.
Or a divinyl compound copolymerizable with the various monomers mentioned above,
Other methods include a method of adding and reacting a polyfunctional compound capable of reacting with a functional group of a polymer, such as a carboxylate group, to form a crosslink, and a reaction between crosslinking groups present in the polymer. The composition of the water-absorbing resin may be selected depending on the purpose. For example, if the purpose is a molded product with excellent water absorption, an anionic cross-linked polymer is preferable, and if the purpose is a molded product with excellent salt resistance and water absorption, an amphoteric polymer is preferable. Crosslinked polymers are preferred.

The active hydrogen-containing compound and organic polyisocyanate may be the same as those used in producing the polyurethane resin of polymer (1).

[0029] When producing the polymer (1), it is obtained by polymerizing each component other than the urethane resin in a urethane resin, its solution, or its dispersion. When urethane resins are divided into hydrophilic urethane resins and hydrophobic urethane resins, hydrophilic urethane resins have ions or ion-forming groups (carboxyl groups, sulfone groups, quaternary ammonium bases, etc.) or nonionic polar groups (hydroxyl groups). ,
polyethylene oxide group, amide group, pyrrolidone group, etc.)
It is a urethane resin that has in its molecule and has a high affinity for water, and the term "hydrophobic urethane resin" refers to urethane resins other than hydrophilic urethane resins. When the urethane resin is a hydrophilic urethane resin, it is preferable to carry out solution polymerization of each component other than the urethane resin in the resin or in a solvent solution. In the case of a hydrophobic urethane resin, solution polymerization may be carried out in the resin or in a solvent solution, but it is better to carry out reverse-phase emulsion polymerization or reverse-phase suspension polymerization of a hydrophilic monomer in a hydrophobic solvent solution. As the urethane resin, a hydrophilic urethane resin is preferable.

[0030] Examples of the hydrophobic solvent used for reverse-phase emulsion polymerization and reverse-phase suspension polymerization in a hydrophobic solvent include aliphatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, aromatic hydrocarbons, mineral oil, etc. Any hydrophobic material can be used. Preferred among these are aliphatic hydrocarbons and alicyclic hydrocarbons. When performing reverse-phase emulsion polymerization and reverse-phase suspension polymerization, emulsifiers and dispersants are not particularly required, but commonly used emulsifiers and dispersants may be used in combination. Examples include sorbitan monostearate and hydroxyethyl cellulose.

[0031] A polymerization catalyst is used during the above polymerization, but when polymerization is carried out in a hydrophilic medium, it is appropriate to use a water-soluble polymerization catalyst, and when polymerization is carried out in a hydrophobic medium, it is appropriate to use an oil-soluble or water-soluble polymerization catalyst. Both catalysts are used. Usually, the polymerization catalyst used for reverse-phase emulsion polymerization is oil-soluble, and the polymerization catalyst used for reverse-phase suspension polymerization is water-soluble. As an oil-soluble polymerization catalyst,
Examples include azo catalysts such as azobisisobutyronitrile and organic peroxide catalysts such as isobutyl peroxide. Examples of water-soluble polymerization catalysts include azo catalysts such as azobisamidinopropane dihydrochloride, organic peroxide catalysts such as t-butyl permaleic acid, inorganic peroxide catalysts such as potassium persulfate, and other redox catalysts. can be given.

As for the production conditions, the temperature varies depending on the catalyst, but is usually 30 to 160°C, preferably 50 to 130°C.
It is ℃. The time is 1 to 20 hours, preferably 5 to 10 hours.

[0033] When producing the polymer (2), the water-absorbing resin is pulverized into fine particles, dispersed in a non-aqueous solvent, and an active hydrogen compound and an organic polyisocyanate are reacted therein to synthesize a urethane resin. There is a method in which a water-absorbing resin is synthesized by performing reverse-phase emulsion polymerization or reverse-phase suspension polymerization in a hydrophobic solvent, and then a urethane resin is synthesized therein. Here, the non-aqueous solvent refers to a solvent with a water content of 1% or less. In the former case, raw materials for urethane resin such as polyol may be used as the non-aqueous solvent. Further, a urethanization catalyst may be included in the components before polymerization. Examples of the urethanization catalyst include organic tin compounds (for example, dibutyltin oxide, dibutyltin dilaurate, etc.), amines (tributylamine, etc.), and the like. The manufacturing conditions may be the same as those for manufacturing the urethane resin of polymer (1).

The weight ratio of the water-absorbing resin to the urethane resin can be determined depending on the intended use of the molded product, but is usually 3:97 to 80:20 in view of water-absorbing ability and moldability. When the water-absorbing resin content is less than 3, the water-absorbing property is poor, and when it exceeds 80, molding becomes difficult.

The form of the composite resin of urethane resin and water-absorbent resin thus obtained varies depending on various conditions, but it is usually a urethane resin in which the water-absorbent resin is uniformly dissolved or dispersed. The water absorption amount of this composite resin composition after drying is 1
0 to 1,000 g/g, preferably 20 to 1,0
00g/g. Even when immersed in water, there is almost no shedding of the water-absorbing resin, and therefore there is almost no slimy feeling on the resin surface. Urethane resin and water-absorbing resin are efficiently and uniformly dispersed in a microscopic state during composite resin formation.

The obtained composite resin composition may be used as it is by heating and drying to solidify it, or it may be used by adding a polyisocyanate compound and further reacting with the OH group of the urethane resin to solidify it. You can also serve it. As the polyisocyanate compound used here, those used in synthesizing the urethane resin described above can be used as they are. Further, a urethane resin (urethane prepolymer) having an isocyanate group at the end can also be mixed and used. In this case, it is preferable to use a reaction catalyst used in urethane resin synthesis.

In addition, surfactants, organic powders (for example, pulp powder,
starch/cellulose derivatives, natural polysaccharides, etc.), inorganic powders (e.g. permylite, zeolite, silica,
Vermiculite, bentonite, talc, activated carbon, etc.) may be added in appropriate amounts as necessary. Furthermore, antioxidants, plasticizers, fungicides, colorants, medicinal ingredients, fragrances, and the like can be added as necessary. The amount of these extenders and additives is usually 10% by weight based on the weight of the composite resin composition.
% by weight or less.

[0038] The amount of water absorbed in the shape at the time of molding is 10 to 1,000% of its own weight; if it is less than 10%, the amount of water absorbed is too low and its uses are limited. If it exceeds 1,000%, the strength when hydrated becomes so low that it becomes unusable. Furthermore, during equilibrium water absorption, the amount of detachment of the water-absorbing resin hydrogel from the molded product is 10% or less. If the amount exceeds 10%, a slimy feeling will occur on the surface of the molded product, impairing the contact feel.

[0039]

【Example】

The present invention will be explained below with reference to production examples and examples, but the present invention is not limited thereto. In the following, parts represent parts by weight. Production Example 1 Production of Polyurethane Resin A Polycaprolactone diol (molecular weight 2,000) 88.2 parts, poly-3-methylpentane adipate diol (molecular weight 2,000) 88.2 parts, 1,4-butanediol 6.2 4.8 parts of trimethylolpropane, 10.0 parts of α,α'-dimethylolpropionic acid, 78.6 parts of IPDI and 120 parts of acetone were charged into a pressurized reaction vessel, and reacted under pressure at 85°C for 5 hours. After, 1
, 6.0 parts of 4-butanediol and 15 parts of acetone
0 part was added and the reaction was further continued at the same temperature for 3 hours. The solution of polyurethane resin A thus obtained had a concentration of 30% and a viscosity of 1,100 cps/20°C.

Production Example 2 Production of polyurethane resin B Polycarbonate diol (molecular weight 2,000)
69.6 parts, poly-3-methylpentane adipate diol (molecular weight 2,000) 69.6 parts, trimethylolpropane 2.6 parts, 2 mole ethylene oxide adduct of bisphenol A (molecular weight 330) 37.7
8.6 parts of α,α'-dimethylolpropionic acid, 92.0 parts of IPDI, and 120 parts of acetone were charged into a pressurized reaction vessel and reacted under pressure at 85°C for 5 hours to give a terminal NCO% of 2. A prepolymer solution of 68 was obtained. The mixture was then cooled to 5°C, and a mixture of 8.3 parts of N-hydroxyethylethylenediamine, 30 parts of isopropanol, and 120 parts of acetone was added, and the mixture was reacted for 1 hour. The solution of polyurethane resin B thus obtained had a concentration of 51.6% and a viscosity of 850 cps/20°C.

Production Example 3 Production of Polyurethane Resin C 229.9 parts of polytetramethylene ether glycol with a molecular weight of 2,000, and 51.1 parts of IPDI.
parts were mixed and reacted at 100°C for 8 hours to obtain NCO%=3.
．． 40 urethane prepolymers were obtained. Next, 500 parts of methyl ethyl ketone (abbreviated as MEK) was added to make a homogeneous solution, and then 2.4 parts of 2-hydroxylethylethylenediamine, 13.7 parts of isophorone diamine, and 3.0 parts of di-n-butylamine were added to 200 parts of isopropyl alcohol. A solution of the urethane prepolymer was added to the MEK solution of the urethane prepolymer. After the addition was completed, the temperature was raised and the reaction was carried out at 50°C for 8 hours. The solution of polyurethane resin C thus obtained had a concentration of 30% and a viscosity of 1,230c.
ps/20°C.

Production Example 4 Production of water absorbent resin D 30 parts of acrylic acid was added to 9.24 parts of deionized water,
Furthermore, as a neutralizing agent, 20.6 parts of potassium hydroxide with a purity of 85% and 0.0 parts of methylenebisacrylamide were added.
0,832 parts were sequentially added to prepare an aqueous potassium acrylate solution (degree of neutralization: 75%) with a mixed monomer concentration of 70% by weight. This aqueous solution was kept warm at 70°C, and water was added to it.
．． 0g of 2,2'-azobis(2-amidinopropane)
A solution containing 0.208 parts of a dibasic acid was added and immediately spread over the bottom surface of a cylindrical reactor having an inner diameter of about 10 cm (the reactor was previously maintained at 70° C.). Polymerization started after a few seconds, and the reaction was completed within about 1 minute to obtain a dry polymer foamed by the heat of polymerization, which was pulverized to 40 mesh or less to obtain water absorbent resin D in the form of a powdered polymer.

Production Example 5 Production of water-absorbing resin E n-
3 parts of a monomer synthesized by an esterification reaction of 20 moles of ethylene oxide adduct of lauryl alcohol with acrylic acid and 40 parts of toluene were placed in a stirrable reaction vessel, dissolved at 50°C, and purged with nitrogen for 1 hour. While stirring, sodium acrylate (74 mol%) containing methylenebisacrylamide (0.2% based on acrylic acid)
Neutralization) 4 parts out of 16 parts of a 45% aqueous solution were placed in a reaction vessel, and 0.001 part of azobisisobutyronitrile was added. After 30 minutes, the remainder of the sodium acrylate aqueous solution was added dropwise over 1.5 hours, and the mixture was aged at 60°C for 1 hour. After that, it is dehydrated by azeotropy at 70 to 80°C under reduced pressure,
A toluene solution of water absorbent resin emulsion E in which a sodium acrylate crosslinked polymer was dispersed was obtained. The solid content of the water absorbent resin in the emulsion was 25.5 wt%, and the average particle size of the water absorbent resin was 0.2 μm.

Example 1 Solution of polyurethane resin A obtained in Production Example 1 100
The mixture was placed in a stirrable reaction vessel, and the mixture was purged with nitrogen at 50°C for 1 hour. Sodium acrylate (7%) containing methylene bisacrylamide (0.2% based on acrylic acid) with stirring
Put 8 parts out of 32 parts of 45% aqueous solution (4 mol% neutralization) into a reaction container, and add 0.0 azobisisobutyronitrile.
02 parts were added. After 30 minutes, the remainder of the sodium acrylate aqueous solution was added dropwise over 1.5 hours, and the mixture was aged at 60°C for 2 hours. In this way, a transparent composite resin composition F of a polyurethane resin and a water-absorbing resin was obtained.

Example 2 In Example 1, 100 parts of a solution of polyurethane resin B was used instead of 100 parts of a solution of polyurethane resin A, and sodium acrylate (74 mol) containing methylene bisacrylamide (0.2% based on acrylic acid) was used. % neutralization)
Same except that 20 parts of a 60% aqueous solution of a mixture of acryloyloxyethyltrimethylammonium chloride containing methylenebisacrylamide (0.2% to monomer) and acrylic acid (molar ratio 1:1) was used instead of 32 parts of a 45% aqueous solution. Polymerization was carried out to obtain a transparent composite resin composition G of a polyurethane resin in which an amphoteric crosslinked polymer was dispersed and a water-absorbing resin.

Example 3 100 parts of the solution of urethane resin C obtained in Production Example 3 was placed in a stirrable reaction vessel, and the vessel was purged with nitrogen at 50°C for 1 hour. Under stirring, 10 parts of 32 parts of a 45% aqueous solution of sodium acrylate (neutralized at 74 mol %) containing methylenebisacrylamide (0.2% based on acrylic acid) was placed in a reaction vessel, and 0.0 parts of azobisisobutyronitrile was added. 002 parts were added. After 30 minutes, the remainder of the sodium acrylate aqueous solution was added dropwise over 1.5 hours, and the mixture was aged at 60°C for 1 hour. In this way, a composite resin composition H in which a water-absorbing resin was dispersed in a urethane resin was obtained.

Example 4 100 parts of MEK and powdered polymer water absorbent resin D3
0 part was added and stirred to disperse. In this, polytetramethylene ether glycol (molecular weight 2,000) 76.6
and 17.0 parts of IPDI were mixed and reacted at 80° C. for 10 hours to obtain a polymer dispersion solution with NCO%=1.30. Then 2-hydroxylethylethylenediamine
A solution of 0.8 parts of isophoronediamine, 4.56 parts of isophoronediamine, and 1.0 parts of di-n-butylamine dissolved in 66 parts of isopropyl alcohol was poured into the polymer dispersion solution. After the addition was completed, the temperature was raised and the reaction was carried out at 50°C for 8 hours. In this way, a composite resin composition I of a water-absorbing resin and a urethane resin was obtained.

Example 5 29.4 parts of polycaprolactone diol (molecular weight 2,000) was added to 100 parts of water-absorbing resin emulsion E.
Poly-3-methylpentane adipate diol (molecular weight 2,000) 29.4 parts, 1,4-butanediol 2.07 parts, trimethylolpropane 1.6 parts, α,α'-dimethylolpropionic acid 3. 33 parts of IPDI, 26.2 parts of IPDI, and 40 parts of MEK were charged into a reaction vessel, and after reacting at 80°C for 8 hours, 2.0 parts of 1,4-butanediol and 50 parts of MEK were added, and the mixture was further reacted at the same temperature for 3 hours. I let it happen. In this way, a composite resin composition J of a water absorbent resin and a urethane resin was obtained.

Comparative Example 1 100 parts (solid content: 30 parts) of the urethane resin A obtained in Production Example 1 were added with 14.4 parts of a separately synthesized water absorbent resin (composition is the same as the water absorbent resin of Example 1). Composite resin composition G (concentration 44.4%) in which water-absorbing resin is dispersed in urethane resin is prepared by mixing and dispersing in a mixer (dry weight)
) was obtained.

(Test method) A solution of the resin composition was applied onto a glass plate and dried at 80° C. for 1 hour to obtain a dry film thickness of 50 μm. This membrane was peeled off from the glass plate, 5 g of the membrane was cut off, and immersed in ion-exchanged water for 4 hours. After draining for 15 minutes, measure the weight, and calculate 1/5 x 100 of the increase in water absorption (%).
(vs. own weight). Furthermore, the detachability of the hydrogel upon water absorption was evaluated by the evaporation residue method. That is, after measuring the amount of water absorbed by the test piece using a weight change method, it is filtered through an 80-mesh stainless wire mesh. The filtrate was completely evaporated, the amount of residue was measured, and the releasability of the hydrogel was evaluated using the following formula. Detachability (%) = amount of residue・100/5・solid content of water absorbent resin in composite resin composition

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[Table 1]

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[Effects of the Invention] The composite resin composition of the present invention exhibits the following effects. (1) Can be molded into any shape. (2) The ability to incorporate water-absorbing resin into the resin is large, and even if water is absorbed in the molded shape, there is very little separation of the hydrogel, resulting in stable water-absorbing performance and a smooth surface contact feeling (slimy feeling). Alternatively, biosafety is also improved. Since it has the above effects, it can be applied to various uses. For example, food and agricultural films, water-stopping materials for civil engineering, water-absorbing fibers, water-absorbing (wet) paints, paints with a wet feel,
Applications for water absorption and swelling include anti-condensation paint, hygroscopic leather, toys, sanitary products, and concrete curing sheets.

Claims (2)

[Claims] 1. A water-swellable composite resin composition comprising the following polymer (1) and/or polymer (2). Polymer (1): A polymer formed from a mixture of a urethane resin, a hydrophilic monomer, a crosslinking agent, a catalyst, and, if necessary, starch and/or a cellulose derivative. Polymer (2): A polymer formed from a mixture of a nonaqueous dispersion of a water-absorbing resin, an active hydrogen-containing compound, and an organic polyisocyanate. 2. The water-swellable composite resin composition according to claim 1, wherein the urethane resin is a hydrophilic urethane resin.