Patent US3346567A successfully refreshed from Google Patents.
US3346567A
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Preparation of epsilon-caprolactam
Assignee: Stamicarbon BV
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Filing: 1966-01-17
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Granted: 1967-10-10
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Expires: 1986-01-17
Abstract
No abstract record available.
Inventors
- 👤 Jan Van Westerveld
- 👤 Guillaume A T Sligchers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:08
CPC Classifications
C; C07; C07D; C07D201/00; C07D201/02; C07D201/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
64 words
IN PROCESSES FOR THE PREPARATION OF E-CAPROLACTAM BY REACTION OF E-CAPROLACTONE WITH AMMONIA AT AN ELEVATED TEMPERATURE IN THE RANGE OF ABOUT 200-475*C. AND UNDER SUPERATMOSPHERIC PRESSURE, FOLLOWED BY REMOVING OF E-CAPROLACTAM FROM THE REACTION MIXTURE, THE IMPROVEMENT CONSISTING ESSENTIALLY IN RAPIDLY CHILLING THE REACTION MIXTURE TO A LOWER TEMPERATURE IN THE RANGE OF ABOUT 15 TO 100*C., AND THEREAFTER EXTRACTING THE E-CAPROLACTAM THEREFROM.
Claim 2
Dependent Claim
64 words
IN PROCESSES FOR THE PREPARATION OF E-CAPROLACTAM BY REACTION OF E-CAPROLACTONE WITH AMMONIA AT AN ELEVATED TEMPERATURE IN THE RANGE OF ABOUT 200-475*C. AND UNDER SUPERATMOSPHERIC PRESSURE, FOLLOWED BY REMOVING OF E-CAPROLACTAM FROM THE REACTION MIXTURE, THE IMPROVEMENT CONSISTING ESSENTIALLY IN RAPIDLY CHILLING THE REACTION MIXTURE TO A LOWER TEMPERATURE IN THE RANGE OF ABOUT 15 TO 100*C., AND THEREAFTER EXTRACTING THE E-CAPROLACTAM THEREFROM.
References Cited (Backward Citations)
US3000880A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-10-09 | 1971-04-10 | 1971-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-10-09 | 1975-04-10 | 1975-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-10-09 | 1979-04-10 | 1979-10-10 | $7700.00 | Window Closed / Lapsed |