US2871256A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing terephthalic acid esters from alpha, alpha, alpha, alpha',alpha',alpha'-hexachloro-p-xylene
Assignee: Dow Chemical Co
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Filing: 1956-03-02
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Granted: 1959-01-27
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Expires: 1976-03-02
Abstract
No abstract record available.
Inventors
- 👤 Owen D Ivins
- 👤 James D Head
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:53
CPC Classifications
C; C07; C07C; C07C17/00; C07C17/093; C07C17/16
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
101 words
THE METHOD OF MAKING A DIESTER OF TEREPHTHALIC ACID WHICH COMPRISES REACTING A MIXTURE OF A,A,A,A'',A'',A''HEXACHLORO-PARA-XYLENE AND A MONOHYDRIC ALIPHATIC PRIMARY ALCOHOL HAVING 1 TO 6 CARBON ATOMS IN A MOLAR RATIO OF 9 TO 30 MOLES OF THE ALCOHOL PER MOLE OF THE SAID HEXACHLORO-PARA-XYLENE, IN ADMIXTURE WITH FROM 10 TO 30 PERCENT BY WEIGHT BASED UPON SAID HEXACHLOROPARA-XYLENE, OF A FRIEDEL-CRAFTS CATALYST SELECTED FROM THE GROUP CONSISTING OF SULFURIC ACID, AROMATIC SULFONIC ACIDS, AND CHLORIDES AND BROMIDES OF ZINC, IRON, MERCURY, CADMIUM, COBALT, TIN AND NICKEL, BY HEATING SAID MIXTURE UNDER REFLUX AT A TEMPERATURE BETWEEN 60* AND 145*C.
Claim 2
Independent Claim
101 words
THE METHOD OF MAKING A DIESTER OF TEREPHTHALIC ACID WHICH COMPRISES REACTING A MIXTURE OF A,A,A,A'',A'',A''HEXACHLORO-PARA-XYLENE AND A MONOHYDRIC ALIPHATIC PRIMARY ALCOHOL HAVING 1 TO 6 CARBON ATOMS IN A MOLAR RATIO OF 9 TO 30 MOLES OF THE ALCOHOL PER MOLE OF THE SAID HEXACHLORO-PARA-XYLENE, IN ADMIXTURE WITH FROM 10 TO 30 PERCENT BY WEIGHT BASED UPON SAID HEXACHLOROPARA-XYLENE, OF A FRIEDEL-CRAFTS CATALYST SELECTED FROM THE GROUP CONSISTING OF SULFURIC ACID, AROMATIC SULFONIC ACIDS, AND CHLORIDES AND BROMIDES OF ZINC, IRON, MERCURY, CADMIUM, COBALT, TIN AND NICKEL, BY HEATING SAID MIXTURE UNDER REFLUX AT A TEMPERATURE BETWEEN 60* AND 145*C.
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) | 1962-01-26 | 1962-07-28 | 1963-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-01-26 | 1966-07-28 | 1967-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-01-26 | 1970-07-28 | 1971-01-27 | $7700.00 | Window Closed / Lapsed |