US2578326A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of benzene polycarboxylic acids by an oil sublimation process
Assignee: California Research LLC
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Filing: 1949-09-06
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Granted: 1951-12-11
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Expires: 1969-09-06
Abstract
No abstract record available.
Inventors
- 👤 Jr William G Toland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:40
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/54; C07C51/573; C07C51/42; C07C51/43
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
97 words
AN IMPROVED SUBLIMATION PROCESS FOR SEPARATING BENZENE POLYCARBOXYLIC ACIDS IN SUBSTANSTIALLY PURE FORM FROM SOLID MIXTURE CONTAINING THEM, WHICH COMPRISES SUSPENDING THE SOLID MIXTURE IN A HYDROCARBON OIL WHICH BOILS SUBSTANTIALLY IN THE RANGE OF FROM ABOUT 400 TO ABOUT 750* F., HEATING THE SUSPENSION IN AN EVAPORATING ZONE TO A TEMPERATURE BETWEEN ABOUT 415* F. AND ABOUT 750* F WHICH IS BELOW THE MELTING POINT OF THE SOLID MIXTURE, MAINTAINING A REDUCED PRESSURE IN THE EVAPORATING ZONE AND WITHDRAWING A VAPOR PHASE COMPRISING VAPORIZED HYDROCARBON OIL AND THE SUBLIMED BENZENE POLYCHARBOXYLIC ACIDS FROM SAID EVAPORATING ZONE.
Claim 2
Dependent Claim
97 words
AN IMPROVED SUBLIMATION PROCESS FOR SEPARATING BENZENE POLYCARBOXYLIC ACIDS IN SUBSTANSTIALLY PURE FORM FROM SOLID MIXTURE CONTAINING THEM, WHICH COMPRISES SUSPENDING THE SOLID MIXTURE IN A HYDROCARBON OIL WHICH BOILS SUBSTANTIALLY IN THE RANGE OF FROM ABOUT 400 TO ABOUT 750* F., HEATING THE SUSPENSION IN AN EVAPORATING ZONE TO A TEMPERATURE BETWEEN ABOUT 415* F. AND ABOUT 750* F WHICH IS BELOW THE MELTING POINT OF THE SOLID MIXTURE, MAINTAINING A REDUCED PRESSURE IN THE EVAPORATING ZONE AND WITHDRAWING A VAPOR PHASE COMPRISING VAPORIZED HYDROCARBON OIL AND THE SUBLIMED BENZENE POLYCHARBOXYLIC ACIDS FROM SAID EVAPORATING ZONE.
References Cited (Backward Citations)
US1694124A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-12-10 | 1955-06-11 | 1955-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-12-10 | 1959-06-11 | 1959-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-12-10 | 1963-06-11 | 1963-12-11 | $7700.00 | Window Closed / Lapsed |