US4111906A
Expired / Lapsed
US
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Polyimides prepared from perfluoroisopropylidene diamine
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1976-07-19
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Granted: 1978-09-05
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Expires: 1996-07-19
Abstract
Abstract This invention relates to a novel aromatic diamine and more particularly to the use of said diamine for the preparation of thermally stable high-molecular weight polymers including, for example, polyamides, polyamideimides, polyimides, and the like. This diamine is obtained by reacting a stoichometric amount of a disodium salt of 2,2-bis(4-hydroxyphenyl) hexafluoropropane with 4-chloronitrobenzene to obtain an intermediate, 2,2-bis[4-(4-nitrophenoxy)phenyl] hexafluoropropane, which is reduced to the corresponding 2,2-bis[4-(4-aminophenoxy)phenyl] hexafluoropropane.
Inventors
- 👤 Robert J. Jones
- 👤 Michael K. O'Rell
- 👤 Jim M. Hom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:04
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/45; C04B41/46; C04B41/48; C04B41/4838; C04B41/4842; C04B41/488; C04B41/80; C04B41/81; C04B41/82; C04B41/83; C07; C07C; C07C205/00; C07C205/27; C07C205/35; C07C205/36; C07C205/38; C08; C08G; C08G69/00; C08G69/40; C08G73/00; C08G73/06; C08G73/10; C08G73/1046; C08G73/105; C08G73/14
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
51 words
A polyimide consisting essentially of recurring units: ##STR6## where n is an integer sufficient to provide a structure having an average molecular weight of at least 5000 wherein R is an organic radical of 5 to 22 atoms selected from the group consisting of tetravalent aliphatic radicals and tetravalent aromatic radicals.
Claim 2
Dependent Claim
51 words
A polyimide consisting essentially of recurring units: ##STR6## where n is an integer sufficient to provide a structure having an average molecular weight of at least 5000 wherein R is an organic radical of 5 to 22 atoms selected from the group consisting of tetravalent aliphatic radicals and tetravalent aromatic radicals.
Claim 3
Dependent Claim
17 words
The polyimide according to claim 1 further characterized in that R has at least one benzene ring.
Claim 4
Dependent Claim
19 words
The polyimide according to claim 1 further characterized in that R has an arylene radical containing two benzene rings.
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) | 1981-09-04 | 1982-03-06 | 1982-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-09-04 | 1986-03-06 | 1986-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-09-04 | 1990-03-06 | 1990-09-05 | $7700.00 | Window Closed / Lapsed |