Patent US3578639A successfully refreshed from Google Patents.
US3578639A
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US
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Polyamide-imide-ureas and method of preparation
Assignee: SI Group Inc
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Filing: 1967-10-13
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Granted: 1971-05-11
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Expires: 1987-10-13
Abstract
Abstract POLYAMIDE-IMIDES ARE PREPARED BY REACTING TRIMELLITIC ANHYDRIDE WITH AN AROMATIC DIISOCYANATE. THE PRODUCT GIVES SMOOTHER FILMS OR COPPER WIRE THAN PRODUCTS PREPARED BY REACTING TRIMELLITIC ANHYDRIDE MONO ACID CHLORIDE WITH AN AROMATIC DIAMINE AND ALSO DOES NOT HAVE AMIC ACID GROUPS. A PROTION OF THE AROMATIC DIISOCYANATE CAN BE REPLACED BY AN AROMATIC DIAMINE TO FORM POLYMER GROUPS. CROSS-LINKING CAN BE INTRODUCED BY ADDING SMALL AMOUNTS OF ISOCYANATES HAVING AT LEAST THREE ISOCYANATE GROUPS.
Inventors
- 👤 Howard E Sheffer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:24
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/30; C08G18/34; C08G18/343; C08G18/345; C08G73/00; C08G73/06; C08G73/10; C08G73/14; H; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/303; H01B3/306; H01B3/308
Claims Analysis
Total Claims: 0
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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) | 1974-05-10 | 1974-11-09 | 1975-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-10 | 1978-11-09 | 1979-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-10 | 1982-11-09 | 1983-05-11 | $7700.00 | Window Closed / Lapsed |