Process of making a crosslinked superabsorbent polyurethane foam
US4725628A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 1986 |
| Grant date | Feb 16, 1988 |
| Priority date | — |
| Expiry date | Jul 18, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S521/905
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A superabsorbent polyurethane foam which contains a plurality of polycarbonyl moieties covalently attached to the polyurethane through at least one urethane, thiourethane, or urea linkage. The carbonyl portions of such polycarbonyl moieties can be carbamoyl, substituted carbamoyl, or carboxy or the alkali metal or ammonium salts thereof. The foam can be prepared by mixing an isocyanate-terminated prepolymer with a first compound having at least one isocyanate-reactive group and at least one carbon-carbon double bond, allowing the mixture to react, and then mixing with the resulting product an aqueous solution of a carboxylate-containing second compound having at least one carbon-carbon double bond. A thermally activated free radical initiator is present in the final reaction mixture. Preferably, the polyurethane is derived from an isocyanate-terminated poly(oxyalkylene) polyol having an isocyanate functionality greater than two and the polycarbonyl moieties are derived from second compounds which typically are acrylate or methacrylate salts, i.e., alkali metal or ammonium salts of acrylic or methacrylic acid. The first compound usually is the 2-hydroxyethyl ester of acrylic or meth…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.