US3696076A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Formation of cast films of aromatic polyamides
Assignee: Celanese Corp
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Filing: 1970-05-22
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Granted: 1972-10-03
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Expires: 1990-05-22
Abstract
Abstract AROMATIC DIAMINES AND AROMATIC DIACID HALIDES ARE REACTED TO FORM HIGH-MOLECULAR WEIGHT POLYAMIDES IN A MUTUAL SOLVENT SYSTEM COMPRISING ANHYDROUS GAMMABUTYROLACTONE AND AT LEAST ONE AMINE ACID ACCEPTOR, A DIPOLAR SOLVENT IS ADDED, THE MIXTURE IS NEUTRALIZED WITH A BASE, FILTERED AND THE MIXTURE CAST DIRECTLY ONTO A SUBSTRATE AND CURED TO FORM CLEAR FILMS.
Inventors
- 👤 Elliot A Vogelfanger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:56
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/02; C08J3/09; C08J3/091; C08G; C08G69/00; C08G69/02; C08G69/26; C08G69/32; C08J2377/00; C08J2377/10
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) | 1975-10-03 | 1976-04-03 | 1976-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-03 | 1980-04-03 | 1980-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-03 | 1984-04-03 | 1984-10-03 | $7700.00 | Window Closed / Lapsed |