Microporous polymeric membrane
US4302334A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 1979 |
| Grant date | Nov 24, 1981 |
| Priority date | — |
| Expiry date | Sep 21, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S521/905
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A microporous polymeric membrane is made by preparing a polymer-casting solution, casting a thin film of the casting solution on a support base, allowing partial evaporation of the solvent from the cast film for a predetermined period of time and contacting the partially evaporated film with a leaching liquid to provide the microporous membrane. A membrane with particularly good mechanical strength and hydrophilic properties is formed when the casting solution comprises a vinylidene fluoride polymer and from about 35 to about 85% by weight of a vinyl acetate polymer; and when the acetate polymer is hydrolyzed after the leaching step to convert the acetate groups to hydroxyl groups.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.