Patent US6060893A successfully refreshed from Google Patents.
Patent US4238602A successfully refreshed from Google Patents.
US4238602A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluorine containing polyethers
Assignee: United States Department of the Air Force
•
Filing: 1979-04-26
•
Granted: 1980-12-09
•
Expires: 1999-04-26
Abstract
Abstract A fluorinated polyether is synthesized by (1) reacting perfluoroglutaryl chloride and 1,5-hexafluoropentane diol to provide a fluorinated polyester and (2) converting ester groups of the polyester to ether groups by SF4 reduction. The product obtained is a thermally stable polyether which is particularly useful in providing an elastomeric material for aircraft fuel tank sealants, tire valves, O-rings, hose, gaskets, and the like.
Inventors
- 👤 Warren R. Griffin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:29
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/68; C08G63/682; C08G63/6824; C08G63/6826; C08G65/00; C08G65/002; C08G65/005; C08G65/007
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
20 words
A fluorine-containing polyether having the following structural formula: ##STR3## where n is an integer representing the number of recurring units.
Claim 2
Dependent Claim
20 words
A fluorine-containing polyether having the following structural formula: ##STR3## where n is an integer representing the number of recurring units.
Claim 3
Dependent Claim
16 words
The fluorine-containing polyether according to claim 1 in which n ranges from about 10 to 50.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-09 | 1984-06-09 | 1984-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-09 | 1988-06-09 | 1988-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-09 | 1992-06-09 | 1992-12-09 | $7700.00 | Window Closed / Lapsed |