Porous aromatic imide polymer membrane and a process for its manufacture
US4512893A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 13, 1982 |
| Grant date | Apr 23, 1985 |
| Priority date | — |
| Expiry date | Apr 13, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S55/05
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A porous aromatic imide polymer membrane usable as a gas or liquid separator or concentrator is prepared by a process comprising the steps of: PA1 (1) dissolving 3 to 30% by weight of an aromatic imide polymer which comprises at least 80 molar % of a recurring unit selected from those of the formulae (I) and (II): ##STR1## wherein R represents a divalent aromatic or heterocyclic radical in 70 to 97% by weight of a solvent consisting essentially of a homogeneous mixture of: PA2 (A) 100 parts by weight of a base solvent which consists essentially of at least one polar organic compound and is capable of dissolving therein said aromatic imide polymer in a concentration of 5% by weight or more therein and of evaporating at a temperature of from 50.degree. to 400.degree. C., and PA2 (B) 5 to 150 parts by weight of an additional liquid which consists essentially of at least one polar organic compound, is incapable of dissolving therein 3% by weight or more of said aromatic imide polymer and is capable of evaporating at a smaller evaporating rate than that of said base solvent at the above-mentioned evaporating temperature so as to provide a dope solution: PA1 (2) forming a thin layer of t…
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