US2821519A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stabilization of polymeric n-vinyl pyrrolidones with hydrazino compounds
Assignee: GAF Chemicals Corp
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Filing: 1955-12-30
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Granted: 1958-01-28
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Expires: 1975-12-30
Abstract
No abstract record available.
Inventors
- 👤 Samuel A Glickman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:51
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/16; C08K5/22; C08K5/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
33 words
A PROCESS OF STABILIZING A POLYMERIC N-VINYL PYRROLIDONE AGAINST DISCOLORATION WHICH COMPRISES INCORPORATING WITH SAID PYRROLIDONE A STABILIZING AMOUNT OF HYDRAZINE SELECTED FROM THE CLASS CONSISTING OF HYDRAZINE HVING THE FOLLOWING GENERAL FORMULAE:
Claim 2
Dependent Claim
33 words
A PROCESS OF STABILIZING A POLYMERIC N-VINYL PYRROLIDONE AGAINST DISCOLORATION WHICH COMPRISES INCORPORATING WITH SAID PYRROLIDONE A STABILIZING AMOUNT OF HYDRAZINE SELECTED FROM THE CLASS CONSISTING OF HYDRAZINE HVING THE FOLLOWING GENERAL FORMULAE:
References Cited (Backward Citations)
US2265450A
Cited
US2729690A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-01-27 | 1961-07-29 | 1962-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-01-27 | 1965-07-29 | 1966-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-01-27 | 1969-07-29 | 1970-01-28 | $7700.00 | Window Closed / Lapsed |