US3846376A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermally stable perfluoroalkylene ether bibenzoxazole polymers
Assignee: United States Department of the Air Force
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Filing: 1973-09-26
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Granted: 1974-11-05
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Expires: 1993-09-26
Abstract
Abstract Perfluoroaklylene ether bibenzoxazole polymers, thermally stable at elevated temperatures, are prepared by the condensation of a perfluoroalkylene ether bisaminophenol and a perfluoroalkylene ether diimidate. Because of the high thermal stability and low glass transition temperatures of the polymers, they are eminently suitable for use in aerospace applications where a wide range of temperature conditions is encountered. In particular, the polymers are useful as sealants and seals.
Inventors
- 👤 R Evers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:02
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/22
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
13 words
A THERMALLY STABLE POLYMER CONSISTING ESSENTIALLY OF REPEATING UNITS HAVING THE FOLLOWING FORMULA:
Claim 2
Dependent Claim
13 words
A THERMALLY STABLE POLYMER CONSISTING ESSENTIALLY OF REPEATING UNITS HAVING THE FOLLOWING FORMULA:
Claim 3
Dependent Claim
12 words
The thermally stable polymer of claim 1 in which R is (CF2)8.
Claim 4
Dependent Claim
12 words
The thermally stable polymer of claim 1 in which R is (CF2)O(CF2)2O(CF2).
Claim 5
Dependent Claim
12 words
The thermally stable polymer of claim 1 in which R is (CF2)4O(CF2)2O(CF2).
Claim 6
Dependent Claim
44 words
A process for preparing a thermally stable polymer which comprises reacting in an inert atmosphere 1,11-bis(3-amino-4-hydroxyphenyl)perfluoro-3,9-dioxaundecane with a monomer selected from the group consisting of dimethyl perfluorosebacimidate, dimethyl perfluoro-3,6-dioxasurberimidate dimethyl perfluoro-3,6-dioxaundecanediimidate, the reaction being conducted in hexafluoroisopropanol in the presence of glacial acetic acid.
Claim 7
Dependent Claim
44 words
A process for preparing a thermally stable polymer which comprises reacting in an inert atmosphere 1,11-bis(3-amino-4-hydroxyphenyl)perfluoro-3,9-dioxaundecane with a monomer selected from the group consisting of dimethyl perfluorosebacimidate, dimethyl perfluoro-3,6-dioxasurberimidate dimethyl perfluoro-3,6-dioxaundecanediimidate, the reaction being conducted in hexafluoroisopropanol in the presence of glacial acetic acid.
Claim 8
Dependent Claim
23 words
The process according to claim 5 in which the reaction is conducted at a temperature in the range of about 45* to 58*C.
Claim 9
Dependent Claim
33 words
The process according to claim 6 in which equimolar amounts of 1,11-bis(3-amino-4-hydroxyphenyl)perfluoro-3,9-dioxaundecane and the monomer are reacted and the mol ratio of glacial acetic acid to the monomer is about 4 to 1.
Claim 10
Dependent Claim
13 words
The process according to claim 7 in which the monomer is dimethyl perfluorosebacimidate.
Claim 11
Dependent Claim
13 words
The process according to claim 7 in which the monomer is dimethyl perfluoro-3,6-dioxasuberimidate.
Claim 12
Dependent Claim
13 words
The process according to claim 7 in which the monomer is dimethyl perfluoro-3,6-dioxaundecanediimidate.
Claim 13
Dependent Claim
7 words
As a new composition of matter, 1,11-bis(3-amino-4-hydroxyphenyl)perfluoro-3,9-dioxaundecane.
Claim 14
Dependent Claim
7 words
As a new composition of matter, 1,11-bis(3-amino-4-hydroxyphenyl)perfluoro-3,9-dioxaundecane.
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) | 1977-11-04 | 1978-05-06 | 1978-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-04 | 1982-05-06 | 1982-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-04 | 1986-05-06 | 1986-11-05 | $7700.00 | Window Closed / Lapsed |