US2858334A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of phthalic acids
Assignee: Mid Century Corp
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Filing: 1954-11-26
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Granted: 1958-10-28
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Expires: 1974-11-26
Abstract
No abstract record available.
Inventors
- 👤 Landau Ralph
- 👤 Robert B Egbert
- 👤 Saffer Alfred
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:26
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/16; C07C51/21; C07C51/255; C07C51/265; C07C51/215
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
122 words
IN A PROCESS FOR THE PREPARATION OF PHTHALIC ACIDS AND FORMIC ACID FROM A DIALKYL BENZENE WHEREIN ONE ALKYL CONTAINS FROM 1 TO 4 CARBON ATOMS AND THE OTHER ALKYL GROUP CONTAINS 2 TO 4 CARBON ATOMS AND WHEREIN THE CARBON ATOM OF EACH ALKYL GROUP ATTACHED DIRECTLY TO THE RING HAS AT LEAST 1 HYDROGEN SUBSTITUENT BY REACTING SAID HYDROCARBON WITH MOLECULAR OXYGEN IN THE PRESENCE OF ABOUT 0.1 TO 10% BY WEIGHT OF A MANGANESE OXIDATION CATALYST, AND RECOVERING THE DESIRED ACIDS, THE IMPROVEMENT COMPRISING: REMOVING FROM THE VAPORS OF THE REACTION SYSTEM WATER AND BY-PRODUCT FORMIC ACID AS REQUIRED TO MAINTAIN THE FORMIC ACID CONCENTRATION THEREOF IN THE REACTION MIXTURE BELOW ABOUT 5% AND THE WATER CONCENTRATION BELOW 10%.
Claim 2
Dependent Claim
122 words
IN A PROCESS FOR THE PREPARATION OF PHTHALIC ACIDS AND FORMIC ACID FROM A DIALKYL BENZENE WHEREIN ONE ALKYL CONTAINS FROM 1 TO 4 CARBON ATOMS AND THE OTHER ALKYL GROUP CONTAINS 2 TO 4 CARBON ATOMS AND WHEREIN THE CARBON ATOM OF EACH ALKYL GROUP ATTACHED DIRECTLY TO THE RING HAS AT LEAST 1 HYDROGEN SUBSTITUENT BY REACTING SAID HYDROCARBON WITH MOLECULAR OXYGEN IN THE PRESENCE OF ABOUT 0.1 TO 10% BY WEIGHT OF A MANGANESE OXIDATION CATALYST, AND RECOVERING THE DESIRED ACIDS, THE IMPROVEMENT COMPRISING: REMOVING FROM THE VAPORS OF THE REACTION SYSTEM WATER AND BY-PRODUCT FORMIC ACID AS REQUIRED TO MAINTAIN THE FORMIC ACID CONCENTRATION THEREOF IN THE REACTION MIXTURE BELOW ABOUT 5% AND THE WATER CONCENTRATION BELOW 10%.
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) | 1961-10-27 | 1962-04-28 | 1962-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-10-27 | 1966-04-28 | 1966-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-10-27 | 1970-04-28 | 1970-10-28 | $7700.00 | Window Closed / Lapsed |