Method for preparing an asymmetric semi-permeable membrane
US4873037A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 5, 1988 |
| Grant date | Oct 10, 1989 |
| Priority date | — |
| Expiry date | Oct 5, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C48/08
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method for preparing an asymmetric, semi-permeable membrane containing a uniform microporous structure for gas and liquid separation, including forming a dense separation on one major surface of a microporous support structure. The microporous support structure is initially formed as a solid unitary film, fiber or sheet by the simultaneous extrusion of at least two streams of heat-plastified polymeric materials including at least two differentially soluble polymeric materials. The separation layer can be formed on the support structure prior to or after the soluble polymeric material has been dissolved out of, as by leaching from the solid support structure to form the microporous support for the separation layer. Preparation in this manner greatly reduces the tendency to form undesiralbe pinholes in the membrane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.