Patent US4853325A successfully refreshed from Google Patents.
US3639451A
Expired / Lapsed
US
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Process for esterifying aromatic carboxylic acids
Assignee: Honeywell International Inc
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Filing: 1968-03-25
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Granted: 1972-02-01
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Expires: 1988-03-25
Abstract
Abstract THIS SPECIFICATION DISCLOSES A NOVEL PROCESS FORESTERIFYING AROMATIC CARBOXYLIC ACIDS WHEREBY THE CARBOXYLIC ACID IS HEATED WITH A MIXTURE CONTAINING AT LEAST A STIOCHIO METRIC AMOUNT OF A SATURATED ORTHOESTER OF AN ALIPHATIC ALCOHOL HAVING FROM 1 TO 8 CARBON ATOMS AND A STOICHIOMETRIC EXCESS OF A LOWER SATURATED ALCOHOL IN THE PRESENCES OF A STRONG ACID CATALYST. THIS PROCES IMPROVES THE RATE OF ESTERIFICATION AND ELIMINATES COLORED BY-PRODUCTS. THE PROCESS IS PARTICULARLY SUITABLE FOR THE ESTERIFICATION OF PARTIALLY ESTERIFIED ALKYL TEREPHTHALATES TO DIALKYL TEREPHTHALATES OF HIGH PURITY, AS EVIDENCED BY A LACK OF COLORED BY-PRODUCTS.
Inventors
- 👤 David A Ebert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:32
CPC Classifications
C; C07; C07C; C07C67/00; C07C67/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |