Patent US2802861A successfully refreshed from Google Patents.
US2802861A
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Preparation of diesters of terephthalic acid
Assignee: Shell Development Co
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Filing: 1955-05-23
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Granted: 1957-08-13
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Expires: 1975-05-23
Abstract
No abstract record available.
Inventors
- 👤 Christiaan Pieter Van Dijk
- 👤 Jonge Jacobus Bastiaan De
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:30
CPC Classifications
C; C07; C07C; C07C67/00; C07C67/08; C07C69/00; C07C69/76; C07C69/80; C07C69/82
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
61 words
A PROCESS FOR THE PREPARATION OF DIALKYL ESTERS OF TEREPHTHALIC ACID, SAID PROCESS COMPRISING HEATING A MIXTURE OF A LIQUID LOWER MONOHYDRIC ALKANOL AND TEREPHTHALIC ACID, IN THE MOLAR RATIO OF FROM ABOUT 25 TO 1 TO ABOUT 50 TO 1, AT A TEMPERATURE OF FROM ABOUT 150*C. TOO ABOUT 300*C., AT SUPERATMOSPHERIC PRESSURE AND IN THE ABSENCE OF ANY CATALYST..
Claim 2
Dependent Claim
61 words
A PROCESS FOR THE PREPARATION OF DIALKYL ESTERS OF TEREPHTHALIC ACID, SAID PROCESS COMPRISING HEATING A MIXTURE OF A LIQUID LOWER MONOHYDRIC ALKANOL AND TEREPHTHALIC ACID, IN THE MOLAR RATIO OF FROM ABOUT 25 TO 1 TO ABOUT 50 TO 1, AT A TEMPERATURE OF FROM ABOUT 150*C. TOO ABOUT 300*C., AT SUPERATMOSPHERIC PRESSURE AND IN THE ABSENCE OF ANY CATALYST..
References Cited (Backward Citations)
US2465319A
Cited
US2479066A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-08-12 | 1961-02-11 | 1961-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-08-12 | 1965-02-11 | 1965-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-08-12 | 1969-02-11 | 1969-08-13 | $7700.00 | Window Closed / Lapsed |