US4126589A
Expired / Lapsed
US
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Method for preparation of cation exchange membranes
Assignee: Asahi Kasei Corp
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Filing: 1977-11-14
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Granted: 1978-11-21
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Expires: 1997-11-14
Abstract
Abstract A fluorocarbon polymer membrane having pendant sulfonamide groups is first treated with anion radicals and then hydrolyzed for conversion into a cation exchange membrane having carboxylic groups and sulfonic acid groups.
Inventors
- 👤 Masato Hamada
- 👤 Maomi Seko
- 👤 Yasumichi Yamakoshi
- 👤 Hirotsugu Miyauchi
- 👤 Fumihiko Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:52
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/20; C08J5/22; C08J5/2206; C08J5/2218; C08J5/2231; C08J5/2243; C08J5/225; C08J2327/00; C08J2327/02; C08J2327/12
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
48 words
A method for preparing a fluorocarbon cation exchange membrane, which comprises treating a fluorocarbon polymer membrane having at least some pendant groups of the formula: --CF 2 CF 2 SO 2 NH 2 with anion radicals in an atmosphere free from oxygen and hydrolyzing the thus treated membrane.
Claim 2
Independent Claim
48 words
A method for preparing a fluorocarbon cation exchange membrane, which comprises treating a fluorocarbon polymer membrane having at least some pendant groups of the formula: --CF 2 CF 2 SO 2 NH 2 with anion radicals in an atmosphere free from oxygen and hydrolyzing the thus treated membrane.
Claim 3
Dependent Claim
35 words
A method as in claim 1, wherein the fluorocarbon polymer membrane is a reaction product obtained by the reaction of ammonia with a copolymer comprising fluorinated ethylene and a fluorocarbon vinyl ether having sulfonyl fluoride.
Claim 4
Dependent Claim
67 words
A method as in claim 1, wherein the fluorocarbon polymer membrane is prepared by the reaction of an amount of ammonia with a copolymer of fluorinated ethylene and a fluorocarbon vinyl ether having sulfonyl fluoride groups which is effective to provide --CF 2 CF 2 SO 2 NH 2 groups on one surface of the membrane as surface stratum with a thickness of at least 100 A.
Claim 5
Dependent Claim
21 words
A method as in claim 1, wherein the source for generating anion radicals is a Na-benzene type or Na-naphthalene type compound.
References Cited (Backward Citations)
US3969285A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-11-20 | 1982-05-22 | 1982-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-20 | 1986-05-22 | 1986-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-20 | 1990-05-22 | 1990-11-21 | $7700.00 | Window Closed / Lapsed |