Patent US2912457A successfully refreshed from Google Patents.
US2912457A
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US
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Process for the purification of terephthalic acid esters
Assignee: Henkel AG and Co KGaA
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Filing: 1955-09-22
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Granted: 1959-11-10
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Expires: 1975-09-22
Abstract
No abstract record available.
Inventors
- 👤 Bruno Blaser
- 👤 Wilhelm Jakob Katser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:41
CPC Classifications
C; C07; C07C; C07C69/00; C07C69/76; C07C69/80; C07C69/82; C07C67/00; C07C67/48; C07C67/60
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
58 words
IN A PROCESS OF SEPARATING LOWER ALIPHATIC ALCOHOL DIESTERS OF TEREPHTHALIC ACID FROM IMPURITIES LEADING TO DISCOLORATION ADMIXED THEREWITH, SAID DIESTERS BEING SELECTED FROM THE GROUP CONSISTING OF METHYL AND ETHYL DIESTERS, THE STEP OF HEATING SAID ESTERS TO A TEMPERATURE FROM ABOVE 200 TO ABOUT 330*C. FOR A PERIOD OF TIME OF AT LEAST ABOUT 5 HOURS.
Claim 2
Dependent Claim
58 words
IN A PROCESS OF SEPARATING LOWER ALIPHATIC ALCOHOL DIESTERS OF TEREPHTHALIC ACID FROM IMPURITIES LEADING TO DISCOLORATION ADMIXED THEREWITH, SAID DIESTERS BEING SELECTED FROM THE GROUP CONSISTING OF METHYL AND ETHYL DIESTERS, THE STEP OF HEATING SAID ESTERS TO A TEMPERATURE FROM ABOVE 200 TO ABOUT 330*C. FOR A PERIOD OF TIME OF AT LEAST ABOUT 5 HOURS.
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) | 1962-11-09 | 1963-05-11 | 1963-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-11-09 | 1967-05-11 | 1967-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-11-09 | 1971-05-11 | 1971-11-10 | $7700.00 | Window Closed / Lapsed |