US2969375A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Certification of correction
Assignee: —
•
Filing: —
•
Granted: 1961-01-24
•
Expires: 1978-01-24
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:38
CPC Classifications
C; C07; C07D; C07D201/00; C07D201/16; C07D207/00; C07D207/02; C07D207/18; C07D207/22; C07D207/24; C07D207/26; C07D207/263; C07D207/267
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
67 words
THE PROCESS FOR THE PRODUCTION OF PURIFIED 2-PYRROLIDONE WHICH IS ESSENTIALLY ADAPTED FOR POLYMERIZATION, FROM CRUDE COMMERCIAL 2-PYRROLIDONE, WHICH CONSISTS IN THE STEPS OF SEPARATING WATER FROM THE PYRROLIDONE, AND DISSOLVING THE PYRROLIDONE IN AN ALKYL BENZENE SOLVENT WHICH IS LIQUID AT A TEMPERATURE IN THE RANGE OF ABOUT -20*C. TO -35*C., COOLING THE SOLVENT TO BRING ABOUT CRYSTALLIZATION OF PYRROLIDONE THEREFROM, AND RECOVERING THE CRYSTALLIZED PYRROLIDONE.
Claim 2
Dependent Claim
67 words
THE PROCESS FOR THE PRODUCTION OF PURIFIED 2-PYRROLIDONE WHICH IS ESSENTIALLY ADAPTED FOR POLYMERIZATION, FROM CRUDE COMMERCIAL 2-PYRROLIDONE, WHICH CONSISTS IN THE STEPS OF SEPARATING WATER FROM THE PYRROLIDONE, AND DISSOLVING THE PYRROLIDONE IN AN ALKYL BENZENE SOLVENT WHICH IS LIQUID AT A TEMPERATURE IN THE RANGE OF ABOUT -20*C. TO -35*C., COOLING THE SOLVENT TO BRING ABOUT CRYSTALLIZATION OF PYRROLIDONE THEREFROM, AND RECOVERING THE CRYSTALLIZED PYRROLIDONE.
References Cited (Backward Citations)
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Cited
US2667483A
Cited
US2758991A
Cited
US2828307A
Cited
US2313026A
Cited
GB666717A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-01-24 | 1964-07-25 | 1965-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-01-24 | 1968-07-25 | 1969-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-01-24 | 1972-07-25 | 1973-01-24 | $7700.00 | Window Closed / Lapsed |