Strongly swellable, moderately crosslinked polyvinylpyrrolidone
US5073614A · kind A · utility
12Cited by
1References
20Claims
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Key dates
| Filing date | Oct 18, 1990 |
| Grant date | Dec 17, 1991 |
| Priority date | — |
| Expiry date | Oct 18, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F226/10
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
What is provided herein are strongly swellable, moderately crosslinked polyvinylpyrrolidone polymers in the form of fine, white powders characterized by (a) an aqueous swelling parameter defined by its gel volume of about 15 to 150 ml/g, (b) a Brookfield viscosity in 5% aqueous solution of at least about 10,000 cps, and (c) being prepared directly by a precipitation polymerization process in an organic solvent, in the presence of about 0.2 to 1% by weight of vinylpyrrolidone of a multifunctional crosslinking agent, preferably about 0.25 to 0.6%, and optimally, about 0.35 to 0.6%.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.