Cation exchange membrane of a fluorocarbon polymer and a process for preparing the same
US4626553A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 29, 1985 |
| Grant date | Dec 2, 1986 |
| Priority date | — |
| Expiry date | Apr 29, 2005 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2327/12
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A cation exchange membrane of a fluorocarbon polymer containing pendant carboxylic acid and/or carboxylate groups, preferably having, at a predetermined ratio, pendant carboxylic acid and/or carboxylate groups and pendant sulfonic acid and/or sulfonate groups uniformly distributed therein, is produced by contacting with a reducing agent a fluorocarbon polymer containing pendant groups of the formula: EQU --O(CF.sub.2).sub.m SO.sub.2 X wherein X is a fluorine atom, a chlorine atom, a hydrogen atom, M or OM in which M represents a hydrogen atom, a metal atom or an ammonium group, and m is as defined above, and transforming the resultant to a film. An excellent double-layer type composite cation exchange membrane can be produced by laminating the above-mentioned membrane having pendant carboxylic acid and/or carboxylate groups and pendant sulfonic acid and/or sulfonate groups on a membrane of a fluorocarbon polymer containing pendant sulfonic acid and/or sulfonate groups. In such a type of double-layer cation exchange membrane, both the two membranes are based on the same kind of polymer and, hence, peeling-off at the interface of the two layers can be well prevented while exhibiting …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.