US2780663A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fractional crystallization and crystal washing
Assignee: Standard Oil Co
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Filing: 1953-05-29
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Granted: 1957-02-05
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Expires: 1973-05-29
Abstract
No abstract record available.
Inventors
- 👤 Robert C Gunness
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:03
CPC Classifications
B; B01; B01D; B01D9/00; B01D9/0004; B01D9/0013; B01D9/004
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
92 words
THE METHOD BOILING HIGH PURITY PARAXYLENE FROM A NARROW BOILING HYDROCARBON FRACTION WHICH CONTAINS A SUBSTANTIAL AMOUNT OF PARAXYLENE AND AT LEAST ONE OTHER XYLENE ISOMER WHICH METHOD COMPRISES SELECTIVELY CRYSTALLIZING PARAXYLENE FROM THE HYDROCARBON FRACTION TO OBTAIN A SLURRY OF PARAXYLENE CRYSTALS IN MOTHER LIQUOR, INTRODUCING SAID SLURRY AT THE UPPER PART OF A PURIFICATION ZONE, FILTERING MOTHER LIQUOR FROM CRYSTALS AT THE UPPER PARAT OF SAID ZONE, CONVEYING CRYSTRALS MASS FROM THE UPPER PART TO THE LOWERPART OF SAID ZONE WHILE SUBJECTING SAID MASS TO GRADUALLY INCREASING PRESSURE, INTRODUCING SUFFI-
Claim 2
Independent Claim
92 words
THE METHOD BOILING HIGH PURITY PARAXYLENE FROM A NARROW BOILING HYDROCARBON FRACTION WHICH CONTAINS A SUBSTANTIAL AMOUNT OF PARAXYLENE AND AT LEAST ONE OTHER XYLENE ISOMER WHICH METHOD COMPRISES SELECTIVELY CRYSTALLIZING PARAXYLENE FROM THE HYDROCARBON FRACTION TO OBTAIN A SLURRY OF PARAXYLENE CRYSTALS IN MOTHER LIQUOR, INTRODUCING SAID SLURRY AT THE UPPER PART OF A PURIFICATION ZONE, FILTERING MOTHER LIQUOR FROM CRYSTALS AT THE UPPER PARAT OF SAID ZONE, CONVEYING CRYSTRALS MASS FROM THE UPPER PART TO THE LOWERPART OF SAID ZONE WHILE SUBJECTING SAID MASS TO GRADUALLY INCREASING PRESSURE, INTRODUCING SUFFI-
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) | 1960-02-05 | 1960-08-06 | 1961-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-02-05 | 1964-08-06 | 1965-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-02-05 | 1968-08-06 | 1969-02-05 | $7700.00 | Window Closed / Lapsed |