US4196277A
Expired / Lapsed
US
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Perfluoroisopropylidene dianhydride and polyimides prepared therefrom
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1978-06-12
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Granted: 1980-04-01
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Expires: 1998-06-12
Abstract
Abstract This invention relates to a novel aromatic dianhydride and more particularly to the use of said dianhydride for the preparation of thermally stable high-molecular weight polymers including, for example, polybenzimidazoles, polypyrrones, polyimides, and the like. This dianhydride is obtained by reacting a stoichiometric amount of a disodium salt of 2,2-bis(4-hydroxyphenyl) hexafluoropropane with 4-chloro-N-phenylphthalimide to obtain an intermediate, 2,2-bis[4-(3,4-phenylphthalimidephenoxy)phenyl] hexafluoropropane, which is oxidized to the corresponding bis[4-(3,4-dicarboxyphenoxy)phenyl]perfluoroisopropylidene dianhydride.
Inventors
- 👤 Robert J. Jones
- 👤 Michael K. O'Rell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:05
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/20; C07; C07C; C07C65/00; C07C65/21; C07C65/24; C08G73/10; C08G73/1046; C08G73/1053; C08G73/18
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
8 words
An aromatic dianhydride compound having the structure: ##STR6##
Claim 2
Dependent Claim
8 words
An aromatic dianhydride compound having the structure: ##STR6##
Claim 3
Dependent Claim
51 words
A polyimide consisting essentially of recurring units: ##STR7## 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 divalent aliphatic radicals and divalent aromatic radicals.
Claim 4
Dependent Claim
51 words
A polyimide consisting essentially of recurring units: ##STR7## 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 divalent aliphatic radicals and divalent aromatic radicals.
Claim 5
Dependent Claim
17 words
The polyimide according to claim 2 further characterized in that R has at least one benzene ring.
Claim 6
Dependent Claim
19 words
The polyimide according to claim 2 further characterized in that R has an arylene radical containing two benzene rings.
References Cited (Backward Citations)
US3356648A
Cited
US3879428A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-04-01 | 1983-10-01 | 1984-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-01 | 1987-10-01 | 1988-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-01 | 1991-10-01 | 1992-04-01 | $7700.00 | Window Closed / Lapsed |