US3575924A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cross-linked polyimides
Assignee: Rhone Poulenc SA
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Filing: 1968-07-08
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Granted: 1971-04-20
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Expires: 1988-07-08
Abstract
Abstract THE INVENTION PROVIDES NOVEL CROSS-LINKED POLYIMIDES MADE BY REACTING A DIANHYDRIDE WITH A MOLAR EXCESS OF DIAMINE, REACTING THE PRODUCT WITH AN UNSTAURATED ANHYDRIDE TO PRODUCE AN UNSATURATED POLYAMIDE, AND HEATING THE LATTER TO PRODUCE THE CROSS-LINKED POLYIMIDE.
Inventors
- 👤 Michel Bargain
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:38
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1003; C08G73/1007; C08G73/101; C08G73/1014; B; B32; B32B; B32B27/00; H; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/303; H01B3/306; H01B3/307
Claims Analysis
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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) | 1974-04-19 | 1974-10-19 | 1975-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-19 | 1978-10-19 | 1979-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-19 | 1982-10-19 | 1983-04-20 | $7700.00 | Window Closed / Lapsed |