US4477648A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High-temperature polyimides prepared from 2,2-bis-[(2-halo-4-aminophenoxy)-phenyl]hexafluoropropane
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1983-04-07
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Granted: 1984-10-16
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Expires: 2003-04-07
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
2026-10-26 21:13
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1046; C08G73/105
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
23 words
Polyimide copolymers having groups of the structure: ##STR13## wherein X is a halogen and n is the number of repeating units in series.
Claim 2
Dependent Claim
23 words
Polyimide copolymers having groups of the structure: ##STR13## wherein X is a halogen and n is the number of repeating units in series.
Claim 3
Dependent Claim
18 words
Polyimide copolymers having groups of the structure: ##STR14## wherein n is the number of repeating units in series.
Claim 4
Dependent Claim
18 words
Polyimide copolymers having groups of the structure: ##STR14## wherein n is the number of repeating units in series.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-16 | 1988-04-16 | 1988-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-16 | 1992-04-16 | 1992-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-16 | 1996-04-16 | 1996-10-16 | $7700.00 | Window Closed / Lapsed |