Patent US3288687A successfully refreshed from Google Patents.
US3288687A
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Process for the purification of epsilon- caprolactam by dilution, acidulation and distillation
Assignee: —
•
Filing: —
•
Granted: 1966-11-29
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Expires: 1983-11-29
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:21
CPC Classifications
C; C07; C07C; C07C7/00; C07C7/148; C07C7/17; C07C7/171; C07D; C07D201/00; C07D201/02; C07D201/08; C07D201/16; C07D223/00; C07D223/02; C07D223/06; C07D223/08; C07D223/10
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
74 words
A PROCESS FOR THE PURIFICATION OF CRUDE EPSILON-CAPROLACTAM COMPRISING THE STEPS OF DILUTING SAID CRUDE EPSILONCAPROLCATAM WITH WATER IN THE PROPORTION OF APPROXIMATELY 2 PARTS ADDED WATER TO 5 PARTS CRUDE EPSILONCAPROLACTAM, ACIDULATING THE RESULTANT CRUDE TO A PH RANGE OF 3.2 TO 4.2 WITH AN ADDITIVE CONSISTING ESSENTIALLY OF SULFURIC ACID, SUBJECTING THE RESULTANT MIXTURE TO DISTILLATION TO VAPORIZE THE WATER CONTAINED IN SAID CRUDE CAPROLACTAM, AND SUBJECTING THE RESULTANT CAPROLACTAM TO RECTIFICATION.
Claim 2
Dependent Claim
74 words
A PROCESS FOR THE PURIFICATION OF CRUDE EPSILON-CAPROLACTAM COMPRISING THE STEPS OF DILUTING SAID CRUDE EPSILONCAPROLCATAM WITH WATER IN THE PROPORTION OF APPROXIMATELY 2 PARTS ADDED WATER TO 5 PARTS CRUDE EPSILONCAPROLACTAM, ACIDULATING THE RESULTANT CRUDE TO A PH RANGE OF 3.2 TO 4.2 WITH AN ADDITIVE CONSISTING ESSENTIALLY OF SULFURIC ACID, SUBJECTING THE RESULTANT MIXTURE TO DISTILLATION TO VAPORIZE THE WATER CONTAINED IN SAID CRUDE CAPROLACTAM, AND SUBJECTING THE RESULTANT CAPROLACTAM TO RECTIFICATION.
References Cited (Backward Citations)
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Cited
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-11-28 | 1970-05-30 | 1970-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-11-28 | 1974-05-30 | 1974-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-11-28 | 1978-05-30 | 1978-11-29 | $7700.00 | Window Closed / Lapsed |