US3640969A
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Process for preparing soluble polyimide by the polycondensation of mellophanic dianhydride pyromellitic dianhydrid eand an aromatic diami nefollowed by imidation of the polycondensation product
Assignee: Kureha Corp
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Filing: 1969-02-03
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Granted: 1972-02-08
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Expires: 1989-02-03
Abstract
Abstract A PROCESS FOR PRODUCING A SOLUBLE POLYIMIDE BY THE POLYCONDENSATION OF MELLOPHANIC AND PYROMELLITIC DIANHYDRIDE AND AN AROMATIC DIAMINE, FOLLOWED BY THE IMIDATION OF THE POLYCONDENSATION PRODUCT. A POLYIMIDE SOLUTION THUS PREPARED IS ALSO CLAIMED.
Inventors
- 👤 Shigeyuki Suzuki
- 👤 Isamu Kaneda
- 👤 Hiroshi Nagai
- 👤 Masaaki Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:21
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1042; C08G73/1067
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) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |