Solvent-resistant microporous polymide membranes
US5725769A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 1995 |
| Grant date | Mar 10, 1998 |
| Priority date | — |
| Expiry date | Jul 18, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D71/64
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An asymmetric microporous membrane with exceptional solvent resistance and highly desirable permeability is disclosed. The membrane is made by a solution-casting or solution-spinning process from a copolyamic acid comprising the condensation reaction product in a solvent of at least three reactants selected from certain diamines and dianhydrides and post-treated to imidize and in some cases cross-link the copolyamic acid. The membrane is useful as an uncoated membrane for ultrafiltration, microfiltration, and membrane contactor applications, or may be used as a support for a permselective coating to form a composite membrane useful in gas separations, reverse osmosis, nanofiltration, pervaporation, or vapor permeation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.