US3743624A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Benzofuroisoquinoline polymers and method for synthesizing same
Assignee: United States Department of the Air Force
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Filing: 1972-10-06
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Granted: 1973-07-03
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Expires: 1992-10-06
Abstract
Abstract BENZOFUROISOQUINOLINE LADDER POLYMERS ARE PREPARED BY THE CONDENSATION OF 2,3,7,8-TETRAAMINODIBENZOFURAN WITH AN AROMATIC TETRACARBOXYLIC ACID OR A DIANHYDRIDE THEREOF. THE POLYMERS POSSESS A HIGH DEGREE OF THERMAL STABILITY, A PROPERTY WHICH RENDERS THEM PARTICULARLY SUITABLE FOR USE IN HIGH TEMPERATURE APPLICATIONS SUCH AS IN THE FABRICATION OF PLASTIC COMPOSITES, FIBROUS MATERIALS AND PROTECTIVE COATINGS.
Inventors
- 👤 F Arnold
- 👤 A Sicree
- 👤 Deusen R Van
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:41
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/20
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |