| 摘要 |
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.
|
