US2887497A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of trimellitic anhydride
Assignee: Standard Oil Co
•
Filing: 1957-05-27
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Granted: 1959-05-19
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Expires: 1977-05-27
Abstract
No abstract record available.
Inventors
- 👤 Hodes William
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:05
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/54; C07C51/56
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
89 words
A PROCESS FOR PREPARING TRIMELLITIC ANHYDRIDE WHICH COMPRISES CHARGING TRIMELLITIC ACID AND ACETIC ANHYDRIDE, AS ESSENTIALLY THE ONLY MATERIALS, INTO A HEATING ZONE, SAID ACETIC ANHYDRIDE BEING CHARGED IN AN AMOUNT BETWEEN ABOUT 0.1 AND 3 WEIGHT PERCENT BASED ON ACID, MAINTAINING SAID ZONE AT A TEMPERATURE-PRESSURE RELATIONSHIP BETWEEN ABOUT 180* C. AT ABOUT 0.1 MM. HG AND ABOUT 220* C. AT ABOUT 10 MM. HG, PASSING OVERHEAD VAPOR OF TRIMELLITIC ANHYDRIDE PRODUCED IN SAID ZONE TO A CONDENSING ZONE AND RECEIVING SOLID TRIMELLITIC ANHYDRIDE FROM SAID CONDENSING ZONE.
References Cited (Backward Citations)
US2753373A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-05-18 | 1962-11-17 | 1963-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-05-18 | 1966-11-17 | 1967-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-05-18 | 1970-11-17 | 1971-05-19 | $7700.00 | Window Closed / Lapsed |