US3821297A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of perfluorosulfonyl fluoride perfluorovinyl ethers by thermal decomposition of unstable isomers
Assignee: EIDP Inc
•
Filing: 1972-08-18
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Granted: 1974-06-28
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Expires: 1992-08-18
Abstract
Abstract The separation of primary perfluorosulfonyl fluoride perfluorovinyl ethers from their isomers by selective pyrolysis and the preparation of copolymers of tetrafluoroethylene from the purified isomers is disclosed.
Inventors
- 👤 P Resnick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:15
CPC Classifications
C; C07; C07C; C07C303/00; C07C303/02; C07C59/00; C07C59/125; C07C59/135; C08; C08F; C08F16/00; C08F16/12; C08F16/14; C08F16/24
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
24 words
Process of claim 1 wherein the primary isomer is perfluoro-3, 6-dioxa-4-methyl-7-octene-sulfonyl fluoride and there is also present in the mixture the isomer perfluoro-3,6-dioxa-5-methyl-7-octene-sulfonyl fluoride.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |