US3752791A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of polyamide imides by reacting polycarbonamide with aliphatic diisocyanate and cyclic dicarboxylic acid anhydride
Assignee: Bayer AG
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Filing: 1970-10-23
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Granted: 1973-08-14
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Expires: 1990-10-23
Abstract
Abstract THE INVENTION RELATES TO A PROCESS WHICH COMPRISES REACTING A POLYAMIDE WITH A POLYISOCYANATE HAVING AT LEAST TWO NCO GROUPS, OR A COMPOUND CAPABLE OF REACTING AS SUCH A POLYISOCYANATE UNDER THE REACTION CONDITIONS, AND A CYCLIC DICARBOXYLIC ACID ANHYDRIDE WHICH CONTAINS AT LEAST ONE ADDITIONAL GROUP CAPABLE OF CONDENSATION OR ADDITION, OR A COMPOUND CAPABLE OF FORMING SUCH AN ANHYDRIDE UNDER THE REACTION CONDITIONS, AT A TEMPERATURE OF FROM -20 TO +450*C. PREDOMINANTLY, HIGH MOLECULAR WEIGHT REACTION PRODUCTS, DISTINGUISHED BY THEIR OUTSTANDING SOLUBILITY, ARE OBTAINED.
Inventors
- 👤 W Zecher
- 👤 R Merten
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:52
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/60; C08G18/603; C08G18/30; C08G18/34; C08G73/00; C08G73/06; C08G73/10; C08G73/14
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) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |