US4142037A
Expired / Lapsed
US
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Readily curable fluorocarbon ether bibenzoxazole polymers
Assignee: United States Department of the Air Force
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Filing: 1977-12-21
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Granted: 1979-02-27
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Expires: 1997-12-21
Abstract
Abstract Thermooxidatively and hydrolytically stable perfluoroalkylene ether bibenzoxazole polymers containing hydrocarbon cure sites are synthesized by the polycondensation of a fluorocarbon bis(o-aminophenol) containing a hydrocarbon moiety and a perfluoroalkylene ether diimidate or dithioimidate ester. The polymers are readily curable to elastomers that are resistant to hydrolysis over a wide use-temperature range. Thus, the polymers are especially suitable for use in aerospace applications where extreme environments are encountered. In particular, the polymers are useful as seals, sealants, and the like.
Inventors
- 👤 Robert C. Evers
- 👤 Tonson Abraham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:15
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/22
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
78 words
A perfluoroalkylene ether bibenzoxazole polymer consisting essentially of recurring units having the following structural formula: ##STR27## and e is an integer from 1 to 5, inclusive, or CF 2 (OCF 2 CF 2 ) f O(CF 2 ) 5 O(CF 2 CF 2 O) g CF 2 , where (f+g) equals 4 or 7; x equals 0.05 to 1, y equals zero to 0.95, and (x+y) equals 1; and n is equal to the number of recurring units.
Claim 2
Dependent Claim
78 words
A perfluoroalkylene ether bibenzoxazole polymer consisting essentially of recurring units having the following structural formula: ##STR27## and e is an integer from 1 to 5, inclusive, or CF 2 (OCF 2 CF 2 ) f O(CF 2 ) 5 O(CF 2 CF 2 O) g CF 2 , where (f+g) equals 4 or 7; x equals 0.05 to 1, y equals zero to 0.95, and (x+y) equals 1; and n is equal to the number of recurring units.
Claim 3
Dependent Claim
38 words
The bibenzoxazole polymer of claim 1 in which R f ' is (CF 2 ) 3 CH 2 CH 2 (CF 2 ) 3 ; ##STR28## where (a+b) equals 5; and x equals 1 and y equals zero.
Claim 4
Dependent Claim
38 words
The bibenzoxazole polymer of claim 1 in which R f ' is (CF 2 ) 3 CH 2 CH 2 (CF 2 ) 3 ; ##STR29## where (c+d) equals 6; and x equals 1 and y equals zero.
Claim 5
Dependent Claim
55 words
The bibenzoxazole polymer of claim 1 in which R f ' is (CF 2 ) 3 CH 2 CH 2 (CF 2 ) 3 ; R f " is (CF 2 ) 2 O(CF 2 ) 5 O(CF 2 ) 2 ; ##STR30## where (c+d) equals 6; and x equals 0.10 and y equals 0.90.
Claim 6
Dependent Claim
55 words
The bibenzoxazole polymer of claim 1 in which R f ' is (CF 2 ) 3 CH 2 CH 2 (CF 2 ) 3 ; R f " is (CF 2 ) 2 O(CF 2 ) 5 O(CF 2 ) 2 ; ##STR31## where (a+b) equals 5; and x equals 0.10 and y equals 0.90.
Claim 7
Dependent Claim
51 words
The bibenzoxazole polymer of claim 1 in which R f ' is (CF 2 ) 3 CH═CH(CF 2 ) 3 ; R f " is (CF 2 ) 2 O(CF 2 ) 5 O(CF 2 ) 2 ; ##STR32## where (a+b) equals 5; and x equals 0.10 and y equals 0.90.
Claim 8
Dependent Claim
55 words
The bibenzoxazole polymer of claim 1 in which R f ' is (CF 2 ) 3 CH 2 CH 2 (CF 2 ) 3 ; R f " is (CF 2 ) 2 O(CF 2 ) 5 O(CF 2 ) 2 ; ##STR33## where (c+d) equals 5; and x equals 0.15 and y equals 0.85.
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) | 1982-02-26 | 1982-08-28 | 1983-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-26 | 1986-08-28 | 1987-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-26 | 1990-08-28 | 1991-02-27 | $7700.00 | Window Closed / Lapsed |