Hydrogel composites and superporous hydrogel composites having fast swelling, high mechanical strength, and superabsorbent properties
US6271278A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 1997 |
| Grant date | Aug 7, 2001 |
| Priority date | — |
| Expiry date | May 13, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F291/00
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A superporous hydrogel composite is formed by polymerizing one or more ethylenically-unsaturated monomers, and a multiolefinic crosslinking agent, in the presence of particles of a disintegrant and a blowing agent. The disintegrant, which rapidly absorbs water, serves to greatly increase the mechanical strength of the superporous hydrogel and significantly shorten the time required to absorb water and swell. Superporous hydrogel composites prepared by this method have an average pore size in the range of 10 .mu.m to 3,000 .mu.m. Preferred particles of disintegrant include natural and synthetic charged polymers, such as crosslinked sodium carboxymethylcellulose, crosslinked sodium starch glycolate, and crosslinked polyvinylpyrrolidone. The blowing agent is preferably a compound that releases gas bubbles upon acidification, such as NaHCO.sub.3. Improved hydrogel composites formed without a blowing agent are also provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.