US4077940A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal stabilization of polypyrrolidone against reversion to monomer
Assignee: Chevron USA Inc
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Filing: 1976-09-14
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Granted: 1978-03-07
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Expires: 1996-09-14
Abstract
Abstract Certain aryl esters of bis-arylphosphonous acid are thermal stabilization additives for solid polypyrrolidone at the melt temperature.
Inventors
- 👤 Carroll J. Wedel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:21
CPC Classifications
C; C07; C07F; C07F9/00; C07F9/02; C07F9/28; C07F9/48; C07F9/4866; C07F9/4875; C07F9/4808; C07F9/485; C08; C08K; C08K5/00; C08K5/49; C08K5/51; C08K5/53; C08K5/5393
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
36 words
A composition of matter comprising a major amount of a normally solid poly-2-pyrrolidone and a thermal stabilizing amount, effective to reduce the thermal degradation of said poly-2-pyrrolidone to monomer, of an additive having the formula ##STR3##
Claim 2
Dependent Claim
36 words
A composition of matter comprising a major amount of a normally solid poly-2-pyrrolidone and a thermal stabilizing amount, effective to reduce the thermal degradation of said poly-2-pyrrolidone to monomer, of an additive having the formula ##STR3##
Claim 3
Dependent Claim
25 words
A composition of matter according to claim 1 wherein said additive comprises from about 0.5 weight percent to about 5 weight percent of said composition.
Claim 4
Dependent Claim
23 words
A process for extruding poly-2-pyrrolidone which comprises melt extruding the composition of claim 1 at extruder temperatures in excess of about 270° C.
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) | 1981-03-06 | 1981-09-05 | 1982-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-06 | 1985-09-05 | 1986-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-06 | 1989-09-05 | 1990-03-07 | $7700.00 | Window Closed / Lapsed |