US2530978A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Isolation of xylene isomers
Assignee: Standard Oil Development Co
•
Filing: 1946-08-08
•
Granted: 1950-11-21
•
Expires: 1966-08-08
Abstract
No abstract record available.
Inventors
- 👤 David M Mason
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:08
CPC Classifications
C; C07; C07C; C07C7/00; C07C7/14
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
92 words
THE METHOD OF RECOVERING SUBSTANTIALLY PURE PARA-XYLENE FROM MIXTURES THEREOF WITH METAXYLENE WHICH COMPRISES FORMING A LIQUID SOLUTION OF META- AND PARA-XYLENE WITH A THIRD COMPONENT SELECTED FROM THE CLASS CONSISTING OF ETHYL BENZENE, META-ETHYL TOLUENE, AND A MIXTURE OF METHYL HEXENES AND DIMETHYL PENTENES, COOLING THE SOLUTION TO A TEMPERATURE BELOW -53*C. BUT ABOVE THE EUTECTIC TEMPERATURE OF THE SYSTEM: META-SYLENE-PARA-XYLENE-THIRD COMPONENT, WHEREBY PARA-XYLENE CRYSTALS ARE FORMED AND META-XYLENE IS INHIBITED FROM CRYSTALIZING SPONTANEOUSLY BY THE ACTION OF THE THIRD COMPONENT, AND REMOVING SUBSTANTIALLY PURE PARA-SYLENE CRYSTALS FROMT HE COOLED SOLUTION.
Claim 2
Independent Claim
92 words
THE METHOD OF RECOVERING SUBSTANTIALLY PURE PARA-XYLENE FROM MIXTURES THEREOF WITH METAXYLENE WHICH COMPRISES FORMING A LIQUID SOLUTION OF META- AND PARA-XYLENE WITH A THIRD COMPONENT SELECTED FROM THE CLASS CONSISTING OF ETHYL BENZENE, META-ETHYL TOLUENE, AND A MIXTURE OF METHYL HEXENES AND DIMETHYL PENTENES, COOLING THE SOLUTION TO A TEMPERATURE BELOW -53*C. BUT ABOVE THE EUTECTIC TEMPERATURE OF THE SYSTEM: META-SYLENE-PARA-XYLENE-THIRD COMPONENT, WHEREBY PARA-XYLENE CRYSTALS ARE FORMED AND META-XYLENE IS INHIBITED FROM CRYSTALIZING SPONTANEOUSLY BY THE ACTION OF THE THIRD COMPONENT, AND REMOVING SUBSTANTIALLY PURE PARA-SYLENE CRYSTALS FROMT HE COOLED SOLUTION.
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) | 1953-11-20 | 1954-05-22 | 1954-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-11-20 | 1958-05-22 | 1958-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-11-20 | 1962-05-22 | 1962-11-21 | $7700.00 | Window Closed / Lapsed |