US3575923A
Expired / Lapsed
US
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Aqueous process for the preparation of polyimide resins
Assignee: Monsanto Co
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Filing: 1968-10-11
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Granted: 1971-04-20
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Expires: 1988-10-11
Abstract
Abstract DISCLOSED HEREIN IS AN AQUEOUS PROCESS FOR THE PREPARATION OF POLYIMIDE RESINS WHICH PROCESS COMPRISES REACTING IN AN AQUEOUS MEDIUM: TSP@ (1) BENZOPHENONE TETRACARBOXYLIC DIANHYDRIDE OR BENZOPHEONE TETRACARBOXYLIC ACID AND (2) A WATER SOLUBLE POLYAMINE HAVING AT LEAST TWO PRIMARY AMINO GROUPS PER MOLECULE AT TEMPERATURES OF AT LEAST 60*C. FOR A TIME SUFFICIENT TO FORM RECURRING IMIDE UNITS IN THE POLYMER.
Inventors
- 👤 Robert T Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 02:38
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1003; C08G73/1007; C08G73/1028
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) | 1974-04-19 | 1974-10-19 | 1975-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-19 | 1978-10-19 | 1979-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-19 | 1982-10-19 | 1983-04-20 | $7700.00 | Window Closed / Lapsed |