Patent US2640804A successfully refreshed from Google Patents.
US2640804A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of substituted aromatic compounds
Assignee: Phillips Petroleum Co
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Filing: 1950-12-27
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Granted: 1953-06-02
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Expires: 1970-12-27
Abstract
No abstract record available.
Inventors
- 👤 William B Whitney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:06
CPC Classifications
C; C07; C07C; C07C7/00; C07C7/148; C07C7/14808
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
91 words
A NON-CATALYTIC PROCESS FOR THE SEPARATION OF THE PARA-ISOMER FROM ISOMERIC MIXTURES OF DIALKYL BENZENOID HYDROCARBONS SELECTED FROM THE GROUP CONSISTTING OF XYLENES, DIETHYL BENZENES, CYMENES AND ETHYLTOLUENES WHICH COMPRISES REACTING SAID ISOMERIC MIXTURE WITH SULFUR MONOCHLORIDE AT A TEMPERATURE IN THE RANGE 20 TO 135* C. FOR A PERIOD OF TIME IN THE RANGE 20 TO 30 MINUTES AND AT SUBSTANTIALLY ATMOSPHERIC PRESSURE WHEREBY THE META- AND ORTHO-ISOMERS ARE SELECTIVELY SULFURIZED AND DISTILLING THE SUBSTANTIALLY UNREACTED PARA ISOMER FROM THE RESULTING HIGHER BOILING DISULFIDES OF THE META AND ORTHO ISOMERS.
References Cited (Backward Citations)
US2402635A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-06-01 | 1956-12-01 | 1957-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-01 | 1960-12-01 | 1961-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-01 | 1964-12-01 | 1965-06-02 | $7700.00 | Window Closed / Lapsed |