Patent US3364256A successfully refreshed from Google Patents.
US3364256A
Expired / Lapsed
US
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Process for preparation of high purity terephthalic acid
Assignee: Teijin Ltd
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Filing: 1965-08-31
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Granted: 1968-01-16
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Expires: 1985-08-31
Abstract
No abstract record available.
Inventors
- 👤 Ichikawa Yataro
- 👤 Suzuki Nobuo
- 👤 Tokashiki Michiyuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:54
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/42; C07C51/48
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
128 words
A PROCESS FOR THE PREPARATION OF A HIGH PURITY TEREPHTHALIC ACID WHICH COMPRISES THE STEPS OF SUSPENDING 6 TO 100 PARTS BY WEIGHT OF A CRUDE TEREPHTHALIC ACID SEPARATED FROM A REACTION MIXTURE WHICH HAS BEEN OBTAINED BY OXIDATION OF PARA-DIALKYLBENZENE WITH MOLECULAR OXYGEN IN A LIQUID MEDIUM IN THE PRESENCE OF A COBALTIC COMPOUND, IN 100 PARTS BY WEIGHT OF AT LEAST ONE ALKANOIC ACID HAVING 2 TO 4 CARBON ATOMS AND HAVING A TOTAL WATER CONTENT OF LESS THAT 50% BY WEIGHT, HEATING THE SUSPENSION AT A TEMPERATURE IN THE RANGE OF 180 TO 230*C. UNDER THE CONDITION SUCH THAT AT LEAST 50% BY WEIGHT OF THE FED CRUDE TEREPHTHALIC ACID MAY BE PRESENT IN THE FORM OF A SOLID PHASE, AND THEREAFTER SEPARATING TEREPHTHALIC ACID.
Claim 2
Dependent Claim
128 words
A PROCESS FOR THE PREPARATION OF A HIGH PURITY TEREPHTHALIC ACID WHICH COMPRISES THE STEPS OF SUSPENDING 6 TO 100 PARTS BY WEIGHT OF A CRUDE TEREPHTHALIC ACID SEPARATED FROM A REACTION MIXTURE WHICH HAS BEEN OBTAINED BY OXIDATION OF PARA-DIALKYLBENZENE WITH MOLECULAR OXYGEN IN A LIQUID MEDIUM IN THE PRESENCE OF A COBALTIC COMPOUND, IN 100 PARTS BY WEIGHT OF AT LEAST ONE ALKANOIC ACID HAVING 2 TO 4 CARBON ATOMS AND HAVING A TOTAL WATER CONTENT OF LESS THAT 50% BY WEIGHT, HEATING THE SUSPENSION AT A TEMPERATURE IN THE RANGE OF 180 TO 230*C. UNDER THE CONDITION SUCH THAT AT LEAST 50% BY WEIGHT OF THE FED CRUDE TEREPHTHALIC ACID MAY BE PRESENT IN THE FORM OF A SOLID PHASE, AND THEREAFTER SEPARATING TEREPHTHALIC ACID.
References Cited (Backward Citations)
GB799181A
Cited
US3171856A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-01-15 | 1971-07-17 | 1972-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-01-15 | 1975-07-17 | 1976-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-01-15 | 1979-07-17 | 1980-01-16 | $7700.00 | Window Closed / Lapsed |