US4048190A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of bisphenol-A bisimides
Assignee: General Electric Co
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Filing: 1976-02-17
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Granted: 1977-09-13
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Expires: 1996-02-17
Abstract
Abstract A process for purifying a bisphenol-A bisimide which comprises treating the latter with a polar solvent selected from the class consisting of methanol, acetonitrile, acetone, and diethyl ether.
Inventors
- 👤 Donald S. Johnson
- 👤 Frank J. Williams, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:46
CPC Classifications
C; C07; C07D; C07D209/00; C07D209/02; C07D209/44; C07D209/48
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
72 words
The process for purifying a 4-isomer bisimide of the formula ##STR7## which contains as impurities, at least one of an imide compound selected from the class consisting of ##STR8## which process comprises dissolving at a temperature from 20° to 100° C. the aforementioned 4-isomer bisimide in methanol, for a period of time sufficient to take up in said solvent these impurities, and separating the purified 4-isomer bisimide substantially free of the impurities.
Claim 2
Dependent Claim
72 words
The process for purifying a 4-isomer bisimide of the formula ##STR7## which contains as impurities, at least one of an imide compound selected from the class consisting of ##STR8## which process comprises dissolving at a temperature from 20° to 100° C. the aforementioned 4-isomer bisimide in methanol, for a period of time sufficient to take up in said solvent these impurities, and separating the purified 4-isomer bisimide substantially free of the impurities.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-12 | 1981-03-14 | 1981-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-12 | 1985-03-14 | 1985-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-12 | 1989-03-14 | 1989-09-13 | $7700.00 | Window Closed / Lapsed |