US2658045A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyvinyl pyrrolidone gels and process of producing the same
Assignee: GAF Chemicals Corp
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Filing: 1951-03-05
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Granted: 1953-11-03
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Expires: 1971-03-05
Abstract
No abstract record available.
Inventors
- 👤 Schildknecht Calvin Everett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 00:39
CPC Classifications
C; C09; C09J; C09J139/00; C09J139/04; C09J139/06; C08; C08L; C08L2666/00; C08L2666/54; Y; Y10; Y10S; Y10S524/00; Y10S524/916
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
67 words
HYDROUS TO DEHYDRATED GELS OF POLYMERIC N-VINYL PYRROLIDONE OBTAINED BY TREATING AN AQUEOUS SOLUTION OF A WATER SOLUBLE N-VINYL PYRROLIDONE POLYMER WITH AN APPROXIMATELY EQUAL AMOUNT BY WEIGHT OF A WATER SOLUBLE INORGANIC PERSULFATE AND HEATING THE SAME TO CAUSE GELATION, SAID GELS IN HYDROUS FORM BEING CHARACTERIZED IN THAT THEY ARE UNIFORM AND CONTINUOUS AND RESISTANT TO SYNERESIS AND INSENSITIVE TO HEAT UP TO 100* C.
References Cited (Backward Citations)
US2335454A
Cited
US2442330A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-11-02 | 1957-05-04 | 1957-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-11-02 | 1961-05-04 | 1961-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-11-02 | 1965-05-04 | 1965-11-03 | $7700.00 | Window Closed / Lapsed |