US3776949A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of aromatic polycarboxylic acids
Assignee: Lummus Technology LLC
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Filing: 1971-09-07
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Granted: 1973-12-04
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Expires: 1991-09-07
Abstract
Abstract AROMATIC POLYCARBOXYLIC ACIDS AND THEIR ANHYDRIDES ARE PRODUCED FROM THE CORRESPONDING NITRILES BY AQUEOUS CATALYTIC HYDROLYSIS AND COUNTERCURRENT STRIPPING TO PRODUCE AN ACID AMMONIUM SALT OF THE AROMATIC ACID, FOLLOWED BY THERMAL DECOMPOSITION OF THE SALT TO FORM THE ACID, AND PURFICIATION IF NECESSARY.
Inventors
- 👤 A Gelbein
- 👤 B Luberoff
- 👤 M Sze
- 👤 R Whitehead
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:11
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/08; C07C51/41
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) | 1976-12-03 | 1977-06-04 | 1977-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-03 | 1981-06-04 | 1981-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-03 | 1985-06-04 | 1985-12-04 | $7700.00 | Window Closed / Lapsed |