Superabsorbent polymer having improved absorption rate and absorption under pressure
US5314420A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 17, 1993 |
| Grant date | May 24, 1994 |
| Priority date | — |
| Expiry date | Sep 17, 2013 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61F2013/530656
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A superabsorbent polymer having improved absorption under pressure and fast absorption rate is obtained by first providing a solution containing carboxylic acid monomers or water soluble salts thereof, and a crosslinking agent. A carbonate blowing agent and a polymerization initiator are added, individually or in combination, to the solution to form a carbonated monomer solution. A polymerization initiator is then added to the carbonated monomer solution which is then polymerized at temperatures ranging from about 0.degree. C. to about 130.degree. C., forming a microcellular hydrogel. The microcellular hydrogel is chopped or ground into gel pieces having a particle diameter ranging from about 0.1 mm to about 5.0 cm. The gel pieces are dried at temperatures ranging from about 85.degree. C. to about 210.degree. C., and are then ground to form a polymer having a particle size of from about 0.05 mm to about 5.0 mm. A mixture is formed from 100 parts by weight of the polymer and about 0.001 to about 30 parts by weight of a surface crosslinking agent. The polymer is reacted with the surface crosslinking agent to crosslink molecular chains existing on a surface of the polymer, forming the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.