US3792045A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the purification of lactams
Assignee: Inventa AG fuer Forschung und Patentverwertung
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Filing: 1971-12-22
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Granted: 1974-02-12
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Expires: 1991-12-22
Abstract
Abstract A PROCESS CHARACTERIZED IN THAT RAW CAPROLACTAM IS SUBJECTED, IN EITHER SEQUENCE, TO A CRYSTAL EXTRACTION WITH AN ALIPHATIC OR CYCLOALIPHATIC HYDROCARBON HAVING 5-10 CARBON ATOMS AND TO DISTILLATION UNDER REDUCED PRESSURE.
Inventors
- 👤 R Henn
- 👤 D Deiters
- 👤 H Schultze
- 👤 C Berther
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 02:47
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) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |