Patent US3057909A successfully refreshed from Google Patents.
US3057909A
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Esterification of terephthalic acid with aqueous glycol
Assignee: EIDP Inc
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Filing: 1960-10-12
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Granted: 1962-10-09
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Expires: 1980-10-12
Abstract
No abstract record available.
Inventors
- 👤 Frederick J Sebelist
- 👤 Robert H Weir
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:00
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C07; C07C; C07C67/00; C07C67/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
79 words
A PROCESS FOR THE ESTERIFICATION OF TEREPHTHALIC ACID WHICH COMPRISES CONTACTING THE TEREPHTHALIC ACID WITH AQUEOUS ETHYLENE GLYCOL AT A TEMPERATURE OF ABOUT FROM 200 TO 280*C. AND AT A PRESSURE AT LEAST SUFFICIENT TO MAINTAIN THE AQUEOUS GLYCOL IN THE LIQUID PHASE, THE MOLAR RATIO OF WATER TO ETHYLENE PRESENT AT THE START OF THE ESTERIFICATION BEING ABOUT FROM 0.2/1 TO 0.6/1 AND THE MOLAR RATIO OF ETHYLENE GLYCOL TO TEREPHTHALIC ACID BEING ABOUT FROM 5/1 TO 20/1.
Claim 2
Dependent Claim
79 words
A PROCESS FOR THE ESTERIFICATION OF TEREPHTHALIC ACID WHICH COMPRISES CONTACTING THE TEREPHTHALIC ACID WITH AQUEOUS ETHYLENE GLYCOL AT A TEMPERATURE OF ABOUT FROM 200 TO 280*C. AND AT A PRESSURE AT LEAST SUFFICIENT TO MAINTAIN THE AQUEOUS GLYCOL IN THE LIQUID PHASE, THE MOLAR RATIO OF WATER TO ETHYLENE PRESENT AT THE START OF THE ESTERIFICATION BEING ABOUT FROM 0.2/1 TO 0.6/1 AND THE MOLAR RATIO OF ETHYLENE GLYCOL TO TEREPHTHALIC ACID BEING ABOUT FROM 5/1 TO 20/1.
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) | 1965-10-08 | 1966-04-09 | 1966-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-10-08 | 1970-04-09 | 1970-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-10-08 | 1974-04-09 | 1974-10-09 | $7700.00 | Window Closed / Lapsed |