US4521623A
Expired / Lapsed
US
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2,2-Bis[(2-halo-4-aminophenoxy)phenyl]-hexafluoropropane
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1984-02-17
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Granted: 1985-06-04
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Expires: 2004-02-17
Abstract
Abstract There are provided the aromatic diamines 2,2-bis-[(2-halo-4-aminophenoxy)-phenyl]hexafluoropropane, where the attached ortho halogen is preferably chlorine, and 4,4'-bis(4-aminophenoxy)biphenyl, as novel monomers for polyimide polymerizations. The former, when reacted with 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, provides a polyimide having exceptional high-temperature performance. The latter diamine is a low-cost monomer for polyimide production.
Inventors
- 👤 Robert J. Jones
- 👤 Glenn E. C. Chang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:10
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1046; C08G73/105
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
1 words
2,2-bis[(2-halo-4-aminophenoxy)phenyl]hexafluoropropane.
Claim 2
Dependent Claim
1 words
2,2-bis[(2-halo-4-aminophenoxy)phenyl]hexafluoropropane.
Claim 3
Dependent Claim
1 words
2,2-bis[(2-chloro-4-aminophenoxy)phenyl]hexafluoropropane.
Claim 4
Dependent Claim
1 words
2,2-bis[(2-chloro-4-aminophenoxy)phenyl]hexafluoropropane.
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) | 1988-06-03 | 1988-12-03 | 1989-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-03 | 1992-12-03 | 1993-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-03 | 1996-12-03 | 1997-06-04 | $7700.00 | Window Closed / Lapsed |