US2636899A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oxidation process for preparation of terephthalic acid
Assignee: EIDP Inc
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Filing: 1951-01-29
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Granted: 1953-04-28
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Expires: 1971-01-29
Abstract
No abstract record available.
Inventors
- 👤 Burrows Lawton Arthur
- 👤 Cavanaugh Robert Morris
- 👤 Nagle Wesley Michael
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 00:23
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/16; C07C51/27; C07C51/275
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
99 words
A PURPOSE FOR THE MANUFACTURE OF TEREPHTHALIC ACID IN A ONE-STEP OPERATION, WHICH COMPRISES REACTING A P-DIALKYLBENZENE AND DILUTE NITRIC ACID AT SUPERATMOSPHERIC PRESSURE AT A TEMPERATURE BETWEEN 150 AND 250* C., SAID ACID HAVING AN INITIAL STRENGTH BETWEEN 5 AND 60%, AND BEING PRESENT IN A 100% HNO3 RATIO BY WEIGHT BETWEEN 1 TO 10 PARTS TO 1 PART OF THE PDIALKYLBENZENE THE LOWER LIMIT OF SAID PRESSURE BEING THE VAPOR PRESSURE OF WATER AT THE REACTION TEMPERATURE, AND THE UPPER LIMIT OF SAID PRESSURE BEING APPROXIMATELY 2.5 TIMES THE VAPOR PRESSURE OF WATER AT THE REACTION TEMPERATURE.
Claim 2
Dependent Claim
99 words
A PURPOSE FOR THE MANUFACTURE OF TEREPHTHALIC ACID IN A ONE-STEP OPERATION, WHICH COMPRISES REACTING A P-DIALKYLBENZENE AND DILUTE NITRIC ACID AT SUPERATMOSPHERIC PRESSURE AT A TEMPERATURE BETWEEN 150 AND 250* C., SAID ACID HAVING AN INITIAL STRENGTH BETWEEN 5 AND 60%, AND BEING PRESENT IN A 100% HNO3 RATIO BY WEIGHT BETWEEN 1 TO 10 PARTS TO 1 PART OF THE PDIALKYLBENZENE THE LOWER LIMIT OF SAID PRESSURE BEING THE VAPOR PRESSURE OF WATER AT THE REACTION TEMPERATURE, AND THE UPPER LIMIT OF SAID PRESSURE BEING APPROXIMATELY 2.5 TIMES THE VAPOR PRESSURE OF WATER AT THE REACTION TEMPERATURE.
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) | 1956-04-27 | 1956-10-27 | 1957-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-04-27 | 1960-10-27 | 1961-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-04-27 | 1964-10-27 | 1965-04-28 | $7700.00 | Window Closed / Lapsed |