US2573676A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for separating the isomers of hexachlorocyclohexane
Assignee: Stauffer Chemical Co
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Filing: 1948-09-07
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Granted: 1951-11-06
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Expires: 1968-09-07
Abstract
No abstract record available.
Inventors
- 👤 Ramsey G Campbell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:58
CPC Classifications
C; C07; C07C; C07C17/00; C07C17/38; C07C17/392
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
96 words
A PROCESS FOR TREATING CRUDE HEXACHLOROCYCLOHEXANE WHICH IS SUBSTANTIALLY FREE OF THE DELTA ISOMER TO OBTAIN A FRACTION CONTAINING AN ENHANCED PROPORTION OF THE GAMMA ISOMER COMPRISING DISSOLVING THE GAMMA ISOMER IN THE HEXACHLOROCYCLOHEXANE WITH CHLOROFORM, HEATING THE CHLOROFORM SOLUTION TO EVAPORATE CHLOROFORM AND INCREASE THE CONCENTRATION OF THE GAMMA ISOMER, COOLING THE RESULTING SOLUTION UNDER QUIESCENT CONDITIONS TO PRECIPITATE SIMULTANEOUSLY RELATIVELY FINE SMALL CRYSTALS OF THE ALPHA ISOMER AND RELATIVELY LARGE MASSIVE CRYSTALS OF THE GAMMA ISOMER, AND SCREENING THE CRYSTALS TO SEPARATE THE CRYSTALS OF ONE ISOMER FROM THE CRYSTALS OF THE OTHER ISOMER.
Claim 2
Dependent Claim
96 words
A PROCESS FOR TREATING CRUDE HEXACHLOROCYCLOHEXANE WHICH IS SUBSTANTIALLY FREE OF THE DELTA ISOMER TO OBTAIN A FRACTION CONTAINING AN ENHANCED PROPORTION OF THE GAMMA ISOMER COMPRISING DISSOLVING THE GAMMA ISOMER IN THE HEXACHLOROCYCLOHEXANE WITH CHLOROFORM, HEATING THE CHLOROFORM SOLUTION TO EVAPORATE CHLOROFORM AND INCREASE THE CONCENTRATION OF THE GAMMA ISOMER, COOLING THE RESULTING SOLUTION UNDER QUIESCENT CONDITIONS TO PRECIPITATE SIMULTANEOUSLY RELATIVELY FINE SMALL CRYSTALS OF THE ALPHA ISOMER AND RELATIVELY LARGE MASSIVE CRYSTALS OF THE GAMMA ISOMER, AND SCREENING THE CRYSTALS TO SEPARATE THE CRYSTALS OF ONE ISOMER FROM THE CRYSTALS OF THE OTHER ISOMER.
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) | 1954-11-05 | 1955-05-07 | 1955-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-11-05 | 1959-05-07 | 1959-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-11-05 | 1963-05-07 | 1963-11-06 | $7700.00 | Window Closed / Lapsed |