Patent US3761467A successfully refreshed from Google Patents.
US3761467A
Expired / Lapsed
US
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Recovery of epsilon-caprolactam
Assignee: Honeywell International Inc
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Filing: 1971-02-11
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Granted: 1973-09-25
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Expires: 1991-02-11
Abstract
Abstract A PROCESS FOR SEPARATING E-CAPROLACTAM FROM AN AQUEOUS SOLUTION HIGHLY CONCENTRATED IN BOTH COLOR-FORMING AND OXIDIZABLE IMPURITIES WHEREBY THE SOLUTION IS FIRST EXTRACTED WITH AN ORGANIC, WATER-IMMISCIBLE SOLVENT FOR E-CAPROLACTAM, THEREBY SEPARATING THE E-CAPROLACTAM FROM THE COLOR-FORMING IMPURITIES AND THE RESULTANT ORGANIC E-CAPROLACTAM SOLUTION IS EXTRACTED WITH AN AQUEOUS SOLUTION, THEREBY SEPARATING THE E-CAPROLACTAM FROM THE OXIDIZABLE IMPURITIES.
Inventors
- 👤 B Williams
- 👤 F Bohn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:09
CPC Classifications
C; C07; C07D; C07D201/00; C07D201/16
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-24 | 1977-03-26 | 1977-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-24 | 1981-03-26 | 1981-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-24 | 1985-03-26 | 1985-09-25 | $7700.00 | Window Closed / Lapsed |