US3703493A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of polyamide-acid solution in aqueous tertiary amine
Assignee: Individual
•
Filing: 1969-07-01
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Granted: 1972-11-21
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Expires: 1989-07-01
Abstract
Abstract POLYAMIDE-ACID SOLUTIONS ARE MADE BY FORMING IN WATER AN ADMIXTURE OF ABOUT EQUIMOLAR DIANHYDRIDE AND DIAMINE AND A TERTIARY AMINE AND OPTIONALLY A SECONDARY AMINE, AT TEMPERATURES BELOW 40*C. TO YIELD SOLUTIONS SUBSTANTIALLY FREE OF IMIDE GROUPS. TERTIARY AMINE INCLUDE PYRIDINE, DIMETHYLETHANOLAMINE, AND N,N,N'',N''TETRAMETHYLBUTANEDIAMINE. THE PRODUCT MAY BE CAST COATED OR ELECTRODEPOSITED AND CURED BY HEATING AT 125* C. TO 300*C. TO PRODUCE INSULATIVE FILMS.
Inventors
- 👤 Fred Holub
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:17
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1067; C08G73/1071; C08G73/1003; C08G73/1007; C08G73/1028; C08G73/1032; C08G73/1057; C08G73/1064
Claims Analysis
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References Cited (Backward Citations)
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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) | 1975-11-21 | 1976-05-22 | 1976-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-21 | 1980-05-22 | 1980-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-21 | 1984-05-22 | 1984-11-21 | $7700.00 | Window Closed / Lapsed |