US4201876A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluorine containing polyethers
Assignee: United States Department of the Air Force
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Filing: 1976-12-08
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Granted: 1980-05-06
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Expires: 1996-12-08
Abstract
Abstract A fluorinated polyether is synthesized by (1) reacting perfluoroglutryl chloride and 1,5-hexafluoropentane diol to provide a fluorinated polyester and (2) converting ester groups of the polyester to ether groups by SF 4 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 09:48
CPC Classifications
C; C07; C07C; C07C59/00; C07C59/235; C07C59/305; C07C59/315; C08; C08G; C08G65/00; C08G65/002; C08G65/005; C08G65/007
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
56 words
A process for preparing a fluorine-containing polyether which comprises the steps of: a. reacting perfluoroglutaryl chloride with 1,5-hexafluoropentane diol in the presence of a catalytic amount of dimethylformamide so as to obtain a fluorinated polyester; and b. reacting the fluorinated polyester with sulfur tetrafluoride in the presence of hydrogen fluoride, thereby obtaining a fluorine-containing polyether product.
Claim 2
Dependent Claim
56 words
A process for preparing a fluorine-containing polyether which comprises the steps of: a. reacting perfluoroglutaryl chloride with 1,5-hexafluoropentane diol in the presence of a catalytic amount of dimethylformamide so as to obtain a fluorinated polyester; and b. reacting the fluorinated polyester with sulfur tetrafluoride in the presence of hydrogen fluoride, thereby obtaining a fluorine-containing polyether product.
Claim 3
Dependent Claim
58 words
The process according to claim 1 in which substantially equimolar amounts of perfluoroglutaryl chloride and 1,5-hexafluoropentane diol are reacted in the presence of about 0.5 to 10 milliliters of dimethylformamide per mole of either of the aforementioned reactants at a temperature ranging from about room temperature to 200° C. for a period of about 1 to 24 hours.
Claim 4
Dependent Claim
56 words
The process according to claim 2 in which the fluorinated polyester is reacted with a molar excess of sulfur tetrafluoride in the presence of 0.5 to 2 moles of hydrogen fluoride per mole of polyester at a temperature in the range of about 50° to 160° C. for a period of about 2 to 24 hours.
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) | 1983-05-06 | 1983-11-05 | 1984-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-05-06 | 1987-11-05 | 1988-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-05-06 | 1991-11-05 | 1992-05-06 | $7700.00 | Window Closed / Lapsed |