Patent US5274120A successfully refreshed from Google Patents.
US5274120A
Expired / Lapsed
US
⏱️ 0.0 years remaining
1-vinyl-3(E)-ethylidene pyrrolidone
Assignee: ISP CAPITAL Inc
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Filing: 1993-03-03
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Granted: 1993-12-28
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Expires: 2013-03-03
Abstract
Abstract What is provided herein is 1-vinyl-3(E)-ethylidene pyrrolidone in a purity of at least 95%, in the form of white, needle-shaped crystals having a melting point of 59°-61° C.
Inventors
- 👤 Susan Y. Tseng
- 👤 Philip F. Wolf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:41
CPC Classifications
C; C07; C07D; C07D207/00; C07D207/02; C07D207/30; C07D207/34; C07D207/36; C07D207/38
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
22 words
The compound 1-vinyl-3(E)-ethylidene pyrrolidone having the formula: ##STR2## in the form of white, needle-shaped crystals having a melting point of 59°-61° C.
Claim 2
Dependent Claim
22 words
The compound 1-vinyl-3(E)-ethylidene pyrrolidone having the formula: ##STR2## in the form of white, needle-shaped crystals having a melting point of 59°-61° C.
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) | 1996-12-27 | 1997-06-28 | 1997-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-12-27 | 2001-06-28 | 2001-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-12-27 | 2005-06-28 | 2005-12-28 | $7700.00 | Window Closed / Lapsed |