JP2000219761A - Water absorbent resin foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin foam being capable of having been molded in any desired form and improved in water absorption performances and surface appearance after water absorption by foaming a water-absorbing resin obtained by reacting a polyalkylene oxide with a polyol and an isocyanate compound in the presence of a thermally decomposable foaming agent. SOLUTION: A polyoxyalkylene oxide (A) having a weight-average molecular weight of 500-500,000 is mixed with a polyol (B) and 0.5-80 pts.wt., per 100 pts.wt. component A, isocyanate compound (C) in such amounts that the ratio (-NCO/-OH) of the sum of the number of the terminal hydroxy groups of component A and that of the hydroxy of component B to the number of the isocyanate groups of component C is 0.5-20, and the resultant mixture is reacted at 70-210 deg.C to obtain a water-absorbing resin comprising a modified polalkylene oxide having a melt viscosity of 1,000-200,000 P (at 170 deg.C under a load of 50 kg/cm2). This resin (100 pts.wt.) is mixed with 1-20 pts.wt. thermally decomposable foaming agent having a decomposition temperature of 100-180 deg.C and thermally expanded to obtain a water-absorbing resin foam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a water-absorbent resin foam. More specifically, free molding is possible,
The present invention relates to a water-absorbent resin foam which provides a water-absorbent material having excellent water-absorbing performance and a good surface state after water absorption.

[0002]

2. Description of the Related Art In recent years, superabsorbent resins have been widely used in the fields of sanitary materials such as disposable diapers and sanitary articles, civil engineering construction materials, agricultural and horticultural materials, and the like. Examples of the superabsorbent resin include a crosslinked acrylate polymer, a crosslinked vinyl alcohol-acrylate copolymer, a crosslinked product of maleic anhydride-grafted polyvinyl alcohol, a crosslinked acrylic acid-methacrylic acid copolymer, and starch- Crosslinked acrylate graft copolymers, crosslinked saponified starch-acrylonitrile graft copolymers, crosslinked carboxymethylcellulose, crosslinked isobutylene-maleic anhydride copolymers, and the like are known.

[0003] Since these superabsorbent resins do not have thermoplasticity, they cannot be formed into sheets, films, etc. by themselves, so that they have a sandwich structure with paper, pulp, etc., or have thermoplastic resins or synthetic resins. After being compounded with rubber and molded, it is used for the above various applications. However, the above-mentioned molding method has a problem in a method of dispersing and fixing the highly water-absorbing resin, and a problem in that the water-absorbing performance is reduced when it is combined with another material. Therefore, free molding is possible, can be used for applications such as sanitary materials, industrial materials such as civil engineering and construction, agricultural and horticultural materials,
There is a demand for a water-absorbing material that has excellent water-absorbing performance and a good surface state after water absorption.

As such a water-absorbing material, for example, a method is known in which a water-soluble resin containing a foaming agent-containing ethylene oxide as a main component is crosslinked with an electron beam and then foamed to obtain a water-absorbent foamed sheet. JP-A-6-172576). However, the above-described method involves a variation in the degree of crosslinking,
It is necessary to treat in an oxygen-free state when there is a large amount of eluted components and when cross-linking with an electron beam, and there is still room for improvement from the point of industrial implementation due to the limitation of the thickness of the sheet. Also,
A water-absorbing resin having thermoplasticity is also known (Japanese Unexamined Patent Publication No.
-325383). However, the water-absorbing resin is easy to mold, but has disadvantages such as a low water absorption rate.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a water-absorbing material which can be freely molded, has excellent water-absorbing performance, and has a good surface condition after absorbing water.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, have obtained a foamed mixture of a polyalkylene oxide-modified water-absorbent resin and a specific foaming agent. It has been found that the resulting water-absorbent resin foam can be freely molded, has excellent water-absorbing performance, and gives a water-absorbent material having a good surface state after water absorption, and has completed the present invention.

That is, the gist of the present invention is to provide (1) 100 parts by weight of a modified polyalkylene oxide as a water-absorbing resin obtained by reacting a polyalkylene oxide and a polyol with an isocyanate compound, and
A water-absorbent resin foam obtained by foaming a mixture consisting of 20 parts by weight; (2) polyalkylene oxide-modified product
The melt viscosity at 70 ° C. and 50 kg / cm ² load is
A water-absorbent resin foam according to (1) having a molecular weight of 1,000 to 200,000 poise; and (3) a polyalkylene oxide comprising polyethylene oxide, polypropylene oxide and ethylene oxide / propylene oxide copolymer having a weight average molecular weight of 500 to 500,000. A water-absorbent resin foam according to (1) or (2), which is at least one member selected from the group consisting of:
(4) The polyol is at least one selected from the group consisting of ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol and 1,9-nonanediol (1) or (2). The water-absorbent resin foam according to (1), wherein the isocyanate compound is 1,6-hexamethylene diisocyanate, dicyclohexylmethane-4,4′-diisocyanate,
4'-diphenylmethane diisocyanate and 2,4
-The water-absorbent resin foam according to (1) or (2), which is at least one member selected from the group consisting of tolylene diisocyanate, and (6) the pyrolytic foaming agent is an inorganic foaming agent, a nitroso compound, or an azo compound. And at least one selected from the group consisting of sulfonyl compounds and (1) to (5).
And a water-absorbent resin foam as described above.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The water-absorbing resin used in the present invention includes a polyalkylene oxide-modified product obtained by reacting a polyalkylene oxide and a polyol with an isocyanate compound. As the modified polyalkylene oxide, a modified polyalkylene oxide having a melt viscosity of 1,000 to 200,000 poise at 170 ° C. and a load of 50 kg / cm ² is suitably used. If the melt viscosity is less than 1000 poise, the amount of eluted after water absorption is increased and the surface state is deteriorated, which is not preferable. When the melt viscosity exceeds 200,000 poise, the moldability deteriorates and the saturated water absorption decreases.

As the polyalkylene oxide constituting the modified polyalkylene oxide, those having a weight average molecular weight of 500,000 to 500,000 are preferably used. Examples thereof include polyethylene oxide, polypropylene oxide, ethylene oxide / propylene oxide copolymer, Examples include polybutylene oxide and mixtures thereof. In particular, polyethylene oxide, polypropylene oxide, ethylene oxide / propylene oxide copolymer having a weight average molecular weight of 2,000 to 100,000, and a mixture thereof are preferably used. When the weight average molecular weight of the above polyalkylene oxide is less than 500, the resulting polyalkylene oxide modified product has an increased water absorbing ability, so that the amount of eluted after water absorption is increased and the surface state is deteriorated. On the other hand, when the weight average molecular weight exceeds 500,000, the melt viscosity becomes extremely high, moldability is deteriorated, and the saturated water absorption is undesirably reduced.

[0010] The polyol constituting the modified polyalkylene oxide together with the polyalkylene oxide includes:
Organic compounds having two hydroxyl groups (-OH) in the same molecule, for example, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol,
Trimethylene glycol, 1,3-butanediol,
2,3-butanediol, 1,4-butanediol,
1,5-pentanediol, hexylene glycol, octylene glycol, glyceryl monoacetate, glyceryl monobutyrate, 1,6-hexanediol,
Examples thereof include 1,9-nonanediol and bisphenol A. Among them, ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, and 1,9-nonanediol are preferably used.

As the isocyanate compound used for crosslinking the above-mentioned polyalkylene oxide and polyol, an organic compound having two or more isocyanate groups in the same molecule, for example, xylylene diisocyanate (XDI), 4,4 ′ -Diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate,
1,8-dimethylbenzol-2,4-diisocyanate, 2,4-tolylene diisocyanate (TDI), T
Examples thereof include urethane isocyanate compounds and polyisocyanate adducts obtained by reacting a dimer of DI such as a trimer of DI, polymethylene polyphenylisocyanate, and trimethylolpropane with a mole number of diisocyanates corresponding to the number of active hydrogens. Among them,
1,6-hexamethylene diisocyanate (HDI),
Dicyclohexylmethane-4,4'-diisocyanate (HMDI), 4,4'-diphenylmethane idisocyanate (MDI), and 2,4-tolylene diisocyanate (TDI) are preferably used. When weather resistance and water resistance are required depending on the intended use, material composition, etc., aliphatic aliphatic isocyanate compounds such as 1,6-hexamethylene diisocyanate (HDI) and dicyclohexylmethane-
4,4'-diisocyanate (HMDI) is preferably used.

The ratio of the polyalkylene oxide to the polyol and the isocyanate compound is determined by the ratio (R value) of the sum of the number of terminal hydroxyl groups of the polyalkylene oxide to the number of hydroxyl groups of the polyol and the number of isocyanate groups of the isocyanate compound. NCO group / -OH group) in a range of 0.5 to 2.0, preferably 0.8 to 1.
7 is selected. When the R value is less than 0.5,
Since the crosslink density is low, it becomes water-soluble, and the surface state after water absorption deteriorates. On the other hand, when the R value exceeds 2.0, the crosslinking density is increased, and the melt viscosity is increased, so that the moldability is deteriorated.

The number of moles of the polyalkylene oxide can be determined by dividing the weight by the weight average molecular weight. When a polyol is added, it is added during a crosslinking reaction between the polyalkylene oxide and the isocyanate compound. By adding a polyol, the melt viscosity of the resulting polyalkylene oxide-modified product can be reduced, and the moldability is improved.

The amount of the isocyanate compound used varies depending on the type of the isocyanate compound and the reaction conditions.
0.5 to 80 parts by weight, preferably 1 to 100 parts by weight
The range is from 50 to 50 parts by weight. If the amount is less than 0.5 part by weight, the crosslinked density of the resulting polyalkylene oxide-modified product will be low, and the molded article will not have sufficient strength.
If it is used in an amount exceeding 80 parts by weight, the resulting polyalkylene oxide-modified product will have too high a crosslinking density and will have poor moldability.

As a method of reacting a polyalkylene oxide and a polyol with an isocyanate compound, a method of reacting in a solution using an appropriate solvent is generally used. A method of reacting in a dispersed state, or a method in which both are uniformly mixed in a powder or solid state and then heated to a predetermined temperature and then reacted, but from the viewpoint of industrial practice, each raw material is continuously melted. A method of feeding, mixing and reacting in a multi-screw extruder is preferred.

[0016] The temperature of the above reaction is usually 70 to 210 ° C. The reaction can be promoted by adding a small amount of triethylamine, triethanolamine, dibutyltin diacetate, dibutyltin dilaurate, stannasoctoate, triethylenediamine, or the like to the reaction system.

As the foaming agent used in the present invention, a pyrolytic foaming agent that generates a gas such as nitrogen gas or carbon dioxide by heating is preferably used. Specific examples of the thermal decomposition type foaming agent include inorganic foaming agents such as ammonium carbonate, sodium bicarbonate and ammonium bicarbonate, nitroso compounds such as dinitrosopentamethylenetetramine, azodicarbonamide, azobisisobutyronitrile. And organic foaming agents such as sulfonyl hydrazide compounds such as azo compounds such as 4,4'-oxybisbenzenesulfonyl hydrazide and p-toluenesulfonyl hydrazide.

The foaming temperature of the foaming agent is preferably between the melting point and the decomposition temperature of the modified polyalkylene oxide, and is usually about 100 to 180 ° C. The amount of the foaming agent to be added is 1 to 20 parts by weight, more preferably 2 to 15 parts by weight, based on 100 parts by weight of the modified polyalkylene oxide. If the amount is less than 1 part by weight, a sufficient expansion ratio cannot be obtained, and an improvement in water absorption rate cannot be expected. If the amount exceeds 20 parts by weight, the strength is reduced when the foam is used.

The water-absorbent resin foam of the present invention is obtained by foaming a mixture obtained by mixing a predetermined amount of the foam with the polyalkylene oxide-modified product. The method for mixing the modified polyalkylene oxide and the blowing agent is not particularly limited, and examples thereof include a general mixing method using a roll, an extruder, a kneader, or the like. The method for molding the obtained mixture is not particularly limited, and examples thereof include molding methods such as rolls, calender rolls, presses, extruders, injection, and inflation. It is also possible to adjust the thickness and shape to an arbitrary value at the same time as mixing. Examples of a method of foaming the mixture of the polyalkylene oxide-modified product and the blowing agent obtained by the above method include a method of heating with a commonly used apparatus such as a heating oven, a press, and an extruder. Further, after the mixture obtained by the above mixing method is foamed, it can be molded into an arbitrary shape to obtain a water-absorbent resin foam.

Further, if necessary, thermoplastic resins such as ethylene-vinyl acetate copolymer, polyvinyl chloride, acrylonitrile-butadiene-styrene copolymer, thermoplastic elastomer, polyethylene and polypropylene, natural rubber, and styrene-butadiene rubber , Chloroprene rubber,
It can also be obtained by foaming a rubber alone such as ethylene-propylene rubber alone or by appropriately mixing with two or more rubbers.
In this case, the content of the modified polyalkylene oxide is desirably 20% by weight or more from the viewpoint of maintaining a sufficient water absorbing ability.

The water-absorbent resin foam of the present invention may optionally contain additives such as a plasticizer, a surfactant, a stabilizer, a filler, a coloring agent, a crosslinking agent, and a vulcanization accelerator. Can also. The cell structure of the foam of the present invention is not limited to either open cells or closed cells, and may be appropriately selected in consideration of water absorption performance and shape retention after water absorption.

[0022]

EXAMPLES The present invention will be described in more detail with reference to production examples, examples and comparative examples, but the present invention is not limited to these examples. In addition, about the test of the modified polyalkylene oxide obtained by the manufacture example, and the evaluation of the water absorption performance of the water absorbent resin foam obtained by the Example and the comparative example, it carried out by the following method. 1. Test items of polyalkylene oxide-modified product and method thereof (1) Water absorption capacity [g (pure water) / g (resin)]: 200 ml of pure water
1 g of a modified polyalkylene oxide was added thereto, and 2 g
After stirring for 4 hours, the mixture was filtered through a 200-mesh wire gauze, and the weight of the gel after filtration was taken as the water absorption capacity. (2) Melt viscosity (poise): 170 ° C., 50 kg / cm
Under the condition of ² weights, die 1mmφ × 1mmL orifice (Shimadzu flow tester CFT-500C)
Was measured.

2. Performance Evaluation Items of Water Absorbent Resin Foam and Method Thereof (1) Water Absorption Rate: Water Absorbent Resin Foam (Sheet 20
mm × 40mm × 2mm, 10mmφ for strand
× 2 mm), was immersed in 200 ml of pure water, taken out every 1, 5, 15, and 60 minutes, and the excess water was removed with a filter paper to measure the weight (W1). The amount of water absorption (g / g) per 1 g of the water-absorbent resin foam was determined from the following formula, and the result was defined as the water absorption rate. Water absorption (g / g) = W1 / W0 (2) Saturated water absorption (g / g): 24 in the same manner as described above.
The amount of water absorption (g / g) after immersion for a period of time was determined, and the saturated water absorption (g / g) was determined.
g). (3) Elution content (%): Three pieces of water-absorbent resin foam (20 mm × 40 mm × 2 mm for sheet, 10 mmφ × 2 mm for strand) immersed in pure water for 5 days at 50 ° C.
The total weight (W1 ') of the three water-absorbent resin foams after being dried to a constant weight with the above is measured, and eluted from the following formula from the total weight (W0') of the three water-absorbent resin foams before immersion. Asked for minutes. Elution (%) = (W0′−W1 ′) / W0 ′ × 100 (4) Surface state after water absorption: The surface state after the water absorption measurement was observed. The evaluation criteria for the surface state after water absorption are as follows. ：: Good surface condition, no gel detachment, no slimy feeling. C: Surface condition is good, but slimy. X: The gel is detached on the surface and has a slimy feeling.

Production Example 1 100 parts by weight of sufficiently dehydrated polyethylene oxide having a weight average molecular weight of 20,000 and ethylene oxide / propylene oxide having a weight average molecular weight of 15,000 (= 80/2)
0) 100 parts by weight of the copolymer, 1.26 parts by weight of 1,4-butanediol, and 0.1 part by weight of dibutyltin dilaurate were put into a storage tank A having a stirrer kept at 70 ° C., and a nitrogen gas atmosphere was added. A homogeneous mixture was obtained below. Separately, dicyclohexylmethane-4,4'-diisocyanate was placed in a storage tank B equipped with a stirrer kept at 30 ° C and stored under a nitrogen gas atmosphere. Mixture in storage tank A and dicyclohexylmethane in storage tank B
4,4'-diisocyanate was metered with a metering pump to 250
g / min and 8.35 g / min, continuously fed to a twin screw extruder set at 170-200 ° C. and mixed with the extruder.
After the reaction, the strand was discharged from the extruder outlet, and pelletized by a pelletizer to obtain a modified polyalkylene oxide. The melt viscosity (170 ° C., 50 kg / cm ² ) of the polyalkylene oxide-modified product thus obtained is as follows:
It was 2000 poise and the water absorption capacity was 40 g / g.

Production Example 2 50 parts by weight of sufficiently dehydrated polyethylene oxide having a weight average molecular weight of 11,000 and ethylene oxide / propylene oxide having a weight average molecular weight of 15,000 (= 80/20)
50 parts by weight of a copolymer, 0.85 of 1,4-butanediol
Parts by weight, 0.1 parts by weight of dibutyltin dilaurate, and 300 parts by weight of toluene were placed in a reaction vessel having a stirrer kept at 110 ° C., to form a uniform mixed solution under a nitrogen gas atmosphere. Thereto, 5.45 parts by weight of cyclohexylmethane diisocyanate was added and reacted for 3 hours. After completion of the reaction, hexane was added, and the mixture was cooled to room temperature to precipitate the formed resin. This slurry was filtered under pressure and dried under reduced pressure to obtain a modified polyethylene oxide. The melt viscosity of the modified polyalkylene oxide thus obtained (17.
(0 ° C., 50 kg / cm ² ) was 35,000 poise, and the water absorption capacity was 30 g / g.

Production Example 3 100 parts by weight of sufficiently dehydrated polyethylene oxide having a weight average molecular weight of 20,000, 13.2 parts by weight of propylene oxide having a weight average molecular weight of 1,000, 1.97 parts by weight of 1,4-butanediol, and 0.1 part by weight of triethylenediamine. 2 parts by weight were put into a storage tank A equipped with a stirrer kept at 110 ° C., and a uniform mixture was obtained under a nitrogen gas atmosphere. Separately, a storage tank B equipped with a stirrer, which is kept at a temperature of 4,4′-diphenylmethane diisocyanate at 50 ° C.
And stored under a nitrogen gas atmosphere. The mixture in the storage tank A and the 4,4'-diphenylmethane diisocyanate in the storage tank B were set to 110 to 140 ° C. at a rate of 154.6 g / min and 12.1 g / min by a metering pump, respectively2.
The mixture was continuously supplied to a screw extruder, mixed and reacted in the extruder, and a strand was discharged from the extruder outlet, and pelletized by a pelletizer to obtain a modified polyalkylene oxide. The melt viscosity (170 ° C., 50 kg / cm ² ) of the polyalkylene oxide-modified product thus obtained is 200
It was 00 poise and the water absorption capacity was 20 g / g.

Example 1 Modified polyalkylene oxide 10 obtained in Production Example 1
0 parts by weight and 5 parts by weight of sodium bicarbonate (trade name; CellMike 266, decomposition temperature 140 to 170 ° C., Sankyo Chemical Co., Ltd.)
Was mixed with a roll set at 70 ° C. to obtain a mixture having a thickness of 1 comprising a mixture of a polyalkylene oxide-modified product and a foaming agent.
mm sheet was obtained. The obtained sheet was heated in a hot air circulating oven at 150 ° C. for 8 minutes for foaming to obtain a water-absorbent resin foam having an expansion ratio of 5 times, and the above-described performance evaluation was performed.

Example 2 Modified polyalkylene oxide 10 obtained in Production Example 2
0 parts by weight and 5 parts by weight of azodicarbonamide (trade name; CellMike CAP-500, decomposition temperature 150 ° C., manufactured by Sankyo Chemical Co., Ltd.) are mixed with a roll set at 70 ° C., and the polyalkylene oxide modified product is mixed. And a sheet having a thickness of 1 mm made of a mixture of a foaming agent. The obtained sheet is heated at 150 ° C. for 8 minutes in a hot air circulating oven to foam it.
A water-absorbent resin foam having an expansion ratio of 6 was obtained, and the above-described performance evaluation was performed.

Example 3 Modified polyalkylene oxide 10 obtained in Production Example 3
0 parts by weight and 10 parts by weight of sodium bicarbonate (trade name; CellMike 266, decomposition temperature 140-170 ° C., Sankyo Chemical Co., Ltd.)
Blended in a Henschel mixer at 120 ° C
The mixture was mixed with a 30 mm extruder (L / D = 25, dalmage screw) set to 1 mm, and a 1 mm thick sheet composed of a mixture of a polyalkylene oxide-modified product and a foaming agent was obtained with a T-die. The obtained sheet is heated at 150 ° C. for 8 minutes in a hot air circulation type oven to foam, and has a foaming ratio of 10
A doubled water-absorbent resin foam was obtained, and the above-described performance evaluation was performed.

Example 4 Modified polyalkylene oxide 10 obtained in Production Example 1
0 parts by weight and 1 part by weight of a foaming agent containing 4,4′-oxybisbenzenesulfonylhydrazide as a component (trade name: CellMike Z-503, decomposition temperature 150 ° C., Sankyo Chemical Co., Ltd.)
) And 0.8 parts by weight of a foaming agent containing dinitrosopentamethylenetetramine as a component (trade name: Cellmic ANP, decomposition temperature 150 ° C, manufactured by Sankyo Chemical Co., Ltd.) using a Henschel mixer, and then blended to 140 ° C. 30mm set
A strand (10 mmφ) of a water-absorbent resin foam having a foaming ratio of 2 was obtained by a strand die using an extruder (L / D = 25, full flight screw), and the above-described performance evaluation was performed.

Comparative Example 1 A 1-mm thick sheet of a polyalkylene oxide-modified product alone was obtained in the same manner as in Example 1 except that no blowing agent was used, and the above-mentioned performance evaluation was performed.

Comparative Example 2 Example 2 was repeated except that the amount of the foaming agent was 25 parts by weight.
In the same manner as in the above, a sheet having a thickness of 1 mm comprising a mixture of a modified polyalkylene oxide and a foaming agent was obtained. The obtained sheet was heated and foamed in the same manner as in Example 2 to obtain a water-absorbent resin foam having a foaming ratio of 14 times, and the above-described performance evaluation was performed. Table 1 summarizes the evaluation results of these examples and comparative examples.

[0033]

[Table 1] As is clear from Table 1, the water-absorbent resin foam of the present invention has a high water-absorbing property, that is, a high water-absorbing rate, has a small amount of elution, and has an excellent surface state upon water absorption.

[0034]

According to the present invention, it is possible to provide a water-absorbent resin foam which can be freely molded before and after foaming, is excellent in water absorption performance, and has a good surface condition after water absorption.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Jin Ozawa 1-term Irifune-cho, Shimama-ku, Himeji-shi, Hyogo Sumitomo Seika Co., Ltd. 2nd Research Laboratory F term (reference) DA24 DA59 4J034 BA08 CA04 CB03 CB07 CC03 CC08 CC09 CC12 CC61 CC67 DA01 DB04 DB07 DC50 DG03 DG04 DG09 HA01 HA02 HA07 HA11 HB05 HB07 HC03 HC12 HC17 HC22 HC46 HC52 HC61 HC64 HC67 HC71 HC73 JA02 JA38 KC17 Q01 RA01 Q01 RA01

Claims (6)

[Claims] 1. A mixture comprising 100 parts by weight of a polyalkylene oxide-modified product as a water-absorbing resin obtained by reacting a polyalkylene oxide and a polyol with an isocyanate compound, and 1 to 20 parts by weight of a pyrolytic foaming agent. Water-absorbent resin foam obtained by 2. The polyalkylene oxide modified 170
At a load of 50 kg / cm ^{2 and a} melt viscosity of 10
2. The water-absorbent resin foam according to claim 1, wherein the water-absorbent resin foam has a viscosity of 00 to 200,000 poise. 3. The polyalkylene oxide according to claim 1, wherein the polyalkylene oxide is at least one selected from the group consisting of polyethylene oxide, polypropylene oxide and ethylene oxide / propylene oxide copolymer having a weight average molecular weight of 500,000 to 500,000. Water absorbent resin foam. 4. The polyol is ethylene glycol, propylene glycol, 1,4-butanediol, 1,6
3. The water-absorbent resin foam according to claim 1, wherein the foam is at least one selected from the group consisting of -hexanediol and 1,9-nonanediol. 4. 5. The at least one isocyanate compound selected from the group consisting of 1,6-hexamethylene diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, 4,4′-diphenylmethane diisocyanate and 2,4-tolylene diisocyanate. The water-absorbent resin foam according to claim 1, which is one kind. 6. The water absorbent resin foam according to claim 1, wherein the thermal decomposition type foaming agent is at least one selected from the group consisting of an inorganic foaming agent, a nitroso compound, an azo compound, and a sulfonyl hydrazide compound.