US3812159A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polybasic aromatic carboxylic acids,esters and anhydrides
Assignee: M&T Chemicals Inc
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Filing: 1971-06-11
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Granted: 1974-05-21
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Expires: 1991-06-11
Abstract
Abstract THIS INVENTION RELATES TO NOVEL AROMATIC POLYCARBOXYLIC ACIDS, THE ANHYDRIDES AND ISOMERS THEREOF AND MORE PARTICULARLY TO THE USE OF SAID ACIDS AND ANHYDRIDES FOR THE PREPARATION OF THERMALLY STABLE HIGH-MOLECULAR WEIGHT POLYMERS INCLUDING, FOR EXAMPLE, THE POLYAMIDES, POLYBENZIMIDAZOLES, POLYIMIDAZOPYRROLONES, POLYIMIDES, POLYESTERS AND THE LIKE. THESE ACIDS AND/OR ANHYDRIDES ARE OBTAINED BY REACTING STOICHIOMETRIC AMOUNTS OF AN ALKALI METAL C1-C8 MONO- OR POLY-ALKYL SUBSTITUTED PHENOXIDE WITH BIS(CHLOROPHENYL) SULFONE TO OBTAIN BIS(ALKYL-SUBSTITUTED PHENOXYPHENYL) SULFONE INTERMEDIATES WHICH ARE OXIDIZED TO THE CORRESPONDING BIS(CARBOXYPHENOXYPHENYL) SULFONES.
Inventors
- 👤 H Lubowitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:50
CPC Classifications
C; C07; C07C; C07C317/00; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1046; C08G73/1053; C08G73/1057; C08G73/1064; C08G73/1067; C08G73/1071; C08G73/18; C08G73/20; C08G73/22
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) | 1977-05-20 | 1977-11-19 | 1978-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-20 | 1981-11-19 | 1982-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-20 | 1985-11-19 | 1986-05-21 | $7700.00 | Window Closed / Lapsed |