US3179657A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for purifying caprolactam
Assignee: —
•
Filing: —
•
Granted: 1965-04-20
•
Expires: 1982-04-20
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:52
CPC Classifications
C; C07; 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
48 words
IN A PROCESS FOR REFINING A CRUDE LACTAM INCLUDING THE STEPS OF OXIDIZING IT WITH AN OXIDANT IN AQUEOUS SOLUTION AND DISTILLATION, THE IMPROVEMENT WHICH COMPRISES CONDUCTING THE OXIDATION WITH THE LACTAM IN AQUEOUS SOLUTION AT A CONCENTRATION IN THE RANGE OF ABOUT 55 TO 90% BY WEIGHT.
Claim 2
Dependent Claim
48 words
IN A PROCESS FOR REFINING A CRUDE LACTAM INCLUDING THE STEPS OF OXIDIZING IT WITH AN OXIDANT IN AQUEOUS SOLUTION AND DISTILLATION, THE IMPROVEMENT WHICH COMPRISES CONDUCTING THE OXIDATION WITH THE LACTAM IN AQUEOUS SOLUTION AT A CONCENTRATION IN THE RANGE OF ABOUT 55 TO 90% BY WEIGHT.
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) | 1968-04-19 | 1968-10-19 | 1969-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-04-19 | 1972-10-19 | 1973-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-04-19 | 1976-10-19 | 1977-04-20 | $7700.00 | Window Closed / Lapsed |