US2519336A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Separation of dialkyl benzenes
Assignee: Standard Oil Development Co
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Filing: 1946-05-02
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Granted: 1950-08-22
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Expires: 1966-05-02
Abstract
No abstract record available.
Inventors
- 👤 Leland K Beach
- 👤 Charles E Morrell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:48
CPC Classifications
C; C07; C07C; C07C7/00; C07C7/14; C07C7/005; C07C7/148; C07C7/17; C07C7/171
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
165 words
THE METHOD OF SEPARATING PARA XYLENE FROM META XYLENE, WHICH OCMPRISES PREDOMINANTLY SULFONATING META XYLENE IN A FEED MIXTURE OF SAID XYLENES CONTAIING SUFFICIENT PARA XYLENE TO ENABLE PARA XYLENE TO BE SEPARATED THEREFROM BY CRYSTALLIZATION UNTIL AT LEAST ONE-FOURTH OF THE XYLENES REMAIN UNREACTED N THE MIXTURE, SEPARATING A RAFFINATE FRACTION OF THE UNREACTED XYLENES FROM AN ACID EXTRACT OF THE XYLENES SULFONATED IN THE MIXTURE, HEATING THE ACID EXTRACT TO A TEMPERATURE IN THE RANGE 140*C. TO 170*C., STEAM DISTILLING FROM THE ACID EXTRACT THUS HEATED A META XYLENE RICH CUT, HEATING RESIDUAL ACID EXTRACT OF THE STEAM DISTILLATION TO A TEMPERATURE IN THE RANGE 170*C. TO 200*C., STEAM DISTILLING A PARA XYLENE RICH CUT FROM THE THUS-HEATED RESIDUAL ACID EXTRACT, FREEZING OUT PARA XYLENE CRYSTALS FROM THE RAFFINATE AND SAID PARA XYLENE RICH CUT UNTIL MOTHER LIQUORS OF THE CRYSTALLIZATION RETAIN AT LEAST 30% OF PARA XYLENE, AND USING SAID MOTHER LIQUORS IN THE FEED MIXTURE OF SAID SULFONATING AS HEREINBEFORE STATED.
Claim 2
Independent Claim
165 words
THE METHOD OF SEPARATING PARA XYLENE FROM META XYLENE, WHICH OCMPRISES PREDOMINANTLY SULFONATING META XYLENE IN A FEED MIXTURE OF SAID XYLENES CONTAIING SUFFICIENT PARA XYLENE TO ENABLE PARA XYLENE TO BE SEPARATED THEREFROM BY CRYSTALLIZATION UNTIL AT LEAST ONE-FOURTH OF THE XYLENES REMAIN UNREACTED N THE MIXTURE, SEPARATING A RAFFINATE FRACTION OF THE UNREACTED XYLENES FROM AN ACID EXTRACT OF THE XYLENES SULFONATED IN THE MIXTURE, HEATING THE ACID EXTRACT TO A TEMPERATURE IN THE RANGE 140*C. TO 170*C., STEAM DISTILLING FROM THE ACID EXTRACT THUS HEATED A META XYLENE RICH CUT, HEATING RESIDUAL ACID EXTRACT OF THE STEAM DISTILLATION TO A TEMPERATURE IN THE RANGE 170*C. TO 200*C., STEAM DISTILLING A PARA XYLENE RICH CUT FROM THE THUS-HEATED RESIDUAL ACID EXTRACT, FREEZING OUT PARA XYLENE CRYSTALS FROM THE RAFFINATE AND SAID PARA XYLENE RICH CUT UNTIL MOTHER LIQUORS OF THE CRYSTALLIZATION RETAIN AT LEAST 30% OF PARA XYLENE, AND USING SAID MOTHER LIQUORS IN THE FEED MIXTURE OF SAID SULFONATING AS HEREINBEFORE STATED.
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) | 1953-08-21 | 1954-02-20 | 1954-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-08-21 | 1958-02-20 | 1958-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-08-21 | 1962-02-20 | 1962-08-22 | $7700.00 | Window Closed / Lapsed |