US3575936A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chemical and heat conversion of polyamide-acids to polyimides
Assignee: EIDP Inc
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Filing: 1969-02-10
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Granted: 1971-04-20
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Expires: 1989-02-10
Abstract
Abstract THE CHEMICAL AND HEAT CONVERSION OF A POLYAMIDE-ACID TO THE CORRESPONDING POLYIMIDE, USING AS THE CHEMICAL CONVERTING AGENT AN N-ACYL AZOLE COMPOUND, HAVING A 5MEMBERED HETEROCYCLIC RING CONTAINING 2 THROUGH 4 NITROGEN ATOMS AND TWO DOUBLE BONDS.
Inventors
- 👤 Frank J Dinan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:07
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1003; C08G73/1007; C08G73/1028
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) | 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 |