| 摘要 |
PURPOSE:To obtain a water-absorbing polyurethane foam which is excellent in mechanical strengths and water-absorbing properties and has an esp. high water absorption rate by forming the foam at a specified low isocyanate index in the presence of a metal catalyst as the only catalyst. CONSTITUTION:A water-absorbing polyurethane foam is produced by mixing a polyisocyanate with a polyol and mechanically foaming the mixture under conditions that the isocyanate index is 30-50, that the polyol contains water in an amt. of 1.0-3.0 pts.wt. (based on 100 pts.wt. polyol) and a catalyst substantially comprising a metal catalyst only, and that the curing temp. is 100-180 deg.C. Since the index is low and a metal catalyst only is used, chemical foaming is inhibited, giving a foam with high strengths without causing molding defects such as cell collapse. Thus is obtd. a water-absorbing foam which is excellent in strengths and water-absorbing properties, has an esp. high water absorption rate, and is suitable for a cosmetic powder puff, etc. |
