US3714003A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of aryl carboxylic acids
Assignee: Monsanto Co
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Filing: 1970-06-29
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Granted: 1973-01-30
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Expires: 1990-06-29
Abstract
Abstract Aryl carboxylic acids are produced from alkyl substituted aryl compounds or partially oxidized alkyl substituted aryl compounds in an electrolytic cell with a lead containing anode and using chromium in an ionized state in mineral acid as a carrier for electrons. The process is particularly useful in the oxidation of p-toluic acid to terephthalic acid and of tetra-alkyl benzene to tetracarboxylic acids. Both terephthalic acid and tetracarboxylic acids are useful in the production of polyester resins. Trimetallic acid used in making trimellitate plasticizers for polyvinyl chloride resins may also be produced by this process.
Inventors
- 👤 R Engelbrecht
- 👤 R Moore
- 👤 A Engelbrecht
- 👤 J Hill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:18
CPC Classifications
C; C25; C25B; C25B3/00; C25B3/20; C25B3/23; C25B3/01; C25B3/07
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
88 words
A process for the preparation of terephThalic acid which comprises heating an electrolytic cell having a lead-containing anode to a temperature above 70* C and charging to said cell para-toluic acid and chromium in solution in sulfuric acid and passing through said cell a direct electric current whereby said para-toluic acid is oxidized to terephthalic acid by said chromium in an ionized electron-accepting state accepting electrons from said para-toluic acid, carrying them to said anode, discharging them at said anode and there being regenerated to an electron-accepting state.
Claim 2
Dependent Claim
88 words
A process for the preparation of terephThalic acid which comprises heating an electrolytic cell having a lead-containing anode to a temperature above 70* C and charging to said cell para-toluic acid and chromium in solution in sulfuric acid and passing through said cell a direct electric current whereby said para-toluic acid is oxidized to terephthalic acid by said chromium in an ionized electron-accepting state accepting electrons from said para-toluic acid, carrying them to said anode, discharging them at said anode and there being regenerated to an electron-accepting state.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein the electrolytic cell has a lead-containing cathode.
Claim 4
Dependent Claim
15 words
The process of claim 1 wherein the electrolytic cell has a platinum plated steel cathode.
Claim 5
Dependent Claim
13 words
The process of claim 1 wherein the electrolytic cell has a carbon cathode.
Claim 6
Dependent Claim
14 words
The process of claim 1 wherein the lead-containing anode is a lead alloy grid.
References Cited (Backward Citations)
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Cited
US1544357A
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US1998925A
Cited
US3560559A
Cited
US3471555A
Cited
US3423300A
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Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |