US2723994A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oxidation of xylene and toluic acid mixtures to phthalic acids
Assignee: Shell Development Co
•
Filing: 1951-01-15
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Granted: 1955-11-15
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Expires: 1971-01-15
Abstract
No abstract record available.
Inventors
- 👤 Walter R Haefele
- 👤 George W Hearne
- 👤 Seaver A Ballard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 04:17
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/16; C07C51/21; C07C51/255; C07C51/265
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
80 words
IN A PROCESS FOR THE PRODUCTION OF A PHTHALIC ACID WHEREIN A LIQUID MIXTURE CONTAINING XYLENE AND TOLUIC ACID IS OXIDIZED AT ABOUT 100* C. TO 275* C. IN THE PRESENCE OF AN OXIDATION CATALYST BY INTIMATE CONTACT OF THE MIXTURE WITH AN OXYGEN-CONTAINING GAS, THE IMPROVEMENT WHICH COMPRISES ADDING SUCH AMOUNTS OF XYLENE TO SAID MIXTURE DURING THE OXIDATION THAT THE WEIGHT RATIO OF TOLUIC ACID TO XYLENE IN THE MIXTURE IS MAINTAINED BELOW 75:25 BUT ABOVE ABOUT 50:50.
Claim 2
Dependent Claim
80 words
IN A PROCESS FOR THE PRODUCTION OF A PHTHALIC ACID WHEREIN A LIQUID MIXTURE CONTAINING XYLENE AND TOLUIC ACID IS OXIDIZED AT ABOUT 100* C. TO 275* C. IN THE PRESENCE OF AN OXIDATION CATALYST BY INTIMATE CONTACT OF THE MIXTURE WITH AN OXYGEN-CONTAINING GAS, THE IMPROVEMENT WHICH COMPRISES ADDING SUCH AMOUNTS OF XYLENE TO SAID MIXTURE DURING THE OXIDATION THAT THE WEIGHT RATIO OF TOLUIC ACID TO XYLENE IN THE MIXTURE IS MAINTAINED BELOW 75:25 BUT ABOVE ABOUT 50:50.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1958-11-14 | 1959-05-16 | 1959-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-11-14 | 1963-05-16 | 1963-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-11-14 | 1967-05-16 | 1967-11-15 | $7700.00 | Window Closed / Lapsed |