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Patent US3663517A successfully refreshed from Google Patents.
US3663517A
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US
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Preparation of aromatic polyamides by interfacial polycondensation
Assignee: Sumitomo Chemical Co Ltd
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Filing: 1970-10-01
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Granted: 1972-05-16
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Expires: 1990-10-01
Abstract
Abstract A PROCESS FOR PRODUCING AROMATIC POLYAMIDES HAVING A HIGH MOLECULAR WEIGHT, WHICH COMPRISES REACTING AN AROMATIC DIAMINE WITH A DICARBOXYLIC ACID HALIDE IN THE PRESENCE OF AN ACETOPHENONE COMPOUND BY MEANS OF INTERFACIAL POLYCONDENSATION.
Inventors
- 👤 Teruho Adachi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:13
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/02; C08G69/26; C08G69/32
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) | 1975-05-16 | 1975-11-15 | 1976-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-16 | 1979-11-15 | 1980-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-16 | 1983-11-15 | 1984-05-16 | $7700.00 | Window Closed / Lapsed |