Membrane modified hydrogels
US4423099A · kind A · utility
146Cited by
19References
20Claims
0Family size
Assignee
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Key dates
| Filing date | Jul 28, 1980 |
| Grant date | Dec 27, 1983 |
| Priority date | — |
| Expiry date | Jul 28, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Non-uniform water-insoluble interpenetrating polymer blend compositions comprising a first permeable water swellable polymer substrate interpenetrated in a gradient substantially normal to the substrate surface by a second less permeable condensation polymer to form a diffusion rate controlling membrane therein. Such compositions are useful as polymers with reduced permeabilities for water and organic solvents and therefore for the controlled delivery of active ingredients such as fragrances and bio-affecting agents into air or aqueous environments, or in membrane separation processes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.