Patent US3239446A successfully refreshed from Google Patents.
US3239446A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dewaxing of lubricating oils
Assignee: BP PLC
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Filing: 1962-08-31
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Granted: 1966-03-08
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Expires: 1982-08-31
Abstract
No abstract record available.
Inventors
- 👤 Demeester Jacques
- 👤 Maillart Jean-Bernard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:24
CPC Classifications
C; C10; C10G; C10G73/00; C10G73/02; C10G73/06
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
150 words
A PROCESS FOR DEWAXING LUBRICATING OILS BY CRYSTALLIZING-OUT THE PARAFFIN WAX IN A SOLVENT, COMPRISINNG TREATING IN SUCCESSION AT LEAST TWO OILS OF DIFFERING VISCOSITY WITH A SOLVENT HAVING A SUBSTANTIALLY CONSTANT COMPOSITION AND CONTAINING 40-100% BY VOLUME OF METHYL ISOBUTYL KETON AND 60-0% BY VOLUME OF METHYL ETHYL KETONE; ADJUSTING ONLY THE WATER CONTENT OF THE SOLVENT WITHIN THE RANGE 0.1-3.0% BY VOLUME ACCORDING TO THE VISCOSITY OF THE OILS, BY SUBJECTING THE SOLVENT RECOVERED FROM THE DEWAXED OIL AND THE WAX TO A SEPARATE CONTINUOUS DISTILLATION STEP AND THEREIN DEHYDRATING THE SOLVENT TO THE REQUIRED EXTENT WHILE MAINTAINING SUBSTANTIALLY CONSTANT THE CONTENT OF METHYL ISOBUTYL KETONE AND METHYL ETHYL KETONE IN THE SOLVENT, SO THAT THE MOST VISCOUS OIL IS TREATED WITH A SUBSTANTIALLY ANHYDROUS SOLVENT AND THE LESS VISCOUS OIL IS TREATED WITH A WATER-CONTAINING SOLVENT, THE AMOUNT OF WATER INCREASING IN PROPORTION TO THE DECREASING VISCOSITY.
Claim 2
Dependent Claim
150 words
A PROCESS FOR DEWAXING LUBRICATING OILS BY CRYSTALLIZING-OUT THE PARAFFIN WAX IN A SOLVENT, COMPRISINNG TREATING IN SUCCESSION AT LEAST TWO OILS OF DIFFERING VISCOSITY WITH A SOLVENT HAVING A SUBSTANTIALLY CONSTANT COMPOSITION AND CONTAINING 40-100% BY VOLUME OF METHYL ISOBUTYL KETON AND 60-0% BY VOLUME OF METHYL ETHYL KETONE; ADJUSTING ONLY THE WATER CONTENT OF THE SOLVENT WITHIN THE RANGE 0.1-3.0% BY VOLUME ACCORDING TO THE VISCOSITY OF THE OILS, BY SUBJECTING THE SOLVENT RECOVERED FROM THE DEWAXED OIL AND THE WAX TO A SEPARATE CONTINUOUS DISTILLATION STEP AND THEREIN DEHYDRATING THE SOLVENT TO THE REQUIRED EXTENT WHILE MAINTAINING SUBSTANTIALLY CONSTANT THE CONTENT OF METHYL ISOBUTYL KETONE AND METHYL ETHYL KETONE IN THE SOLVENT, SO THAT THE MOST VISCOUS OIL IS TREATED WITH A SUBSTANTIALLY ANHYDROUS SOLVENT AND THE LESS VISCOUS OIL IS TREATED WITH A WATER-CONTAINING SOLVENT, THE AMOUNT OF WATER INCREASING IN PROPORTION TO THE DECREASING VISCOSITY.
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) | 1969-03-07 | 1969-09-06 | 1970-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-03-07 | 1973-09-06 | 1974-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-03-07 | 1977-09-06 | 1978-03-08 | $7700.00 | Window Closed / Lapsed |