US4281105A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Formation of particulate polypyrrolidone
Assignee: Individual
•
Filing: 1980-06-02
•
Granted: 1981-07-28
•
Expires: 2000-06-02
Abstract
Abstract A process for polymerizing 2-pyrrolidone to form a particulate material suitable for melt extrusion processes is disclosed. The process involves agitating to form particles at a critical point during the polymerization in which a friable gel exists. The gel is formed as a result of the addition of polymerization accelerators to the polymerization mixture but as the accelerated polymerization proceeds the gel soon hardens to a tough cake which can no longer be broken up by agitation. If the polymerizing mixture is agitated before the formation of the gel only very fine particles are formed.
Inventors
- 👤 Carl E. Barnes
- 👤 Arthur C. Barnes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:10
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/02; C08G69/08; C08G69/14; C08G69/24
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
84 words
A process for forming particulate polypyrrolidone comprising heating at a temperature of from about 20° to about 70° C. an anhydrous mixture comprising 2-pyrrolidone, an alkaline polymerization catalyst, a polymerization accelerator selected from the group consisting of quaternary ammonium sulfates and bisulfates and a polymerization initiator selected from the group consisting of CO 2 , SO 2 and MoO 3 thereby causing the formation of a friable gel phase of short duration as the polymerization proceeds and agitating the mass while in this phase.
Claim 2
Dependent Claim
84 words
A process for forming particulate polypyrrolidone comprising heating at a temperature of from about 20° to about 70° C. an anhydrous mixture comprising 2-pyrrolidone, an alkaline polymerization catalyst, a polymerization accelerator selected from the group consisting of quaternary ammonium sulfates and bisulfates and a polymerization initiator selected from the group consisting of CO 2 , SO 2 and MoO 3 thereby causing the formation of a friable gel phase of short duration as the polymerization proceeds and agitating the mass while in this phase.
Claim 3
Dependent Claim
14 words
The process described in claim 1 wherein the alkaline polymerization catalyst is potassium pyrrolidonate.
Claim 4
Dependent Claim
14 words
The process described in claim 1 wherein the polymerization initiator is CO 2 .
Claim 5
Dependent Claim
14 words
The process described in claim 1 wherein the polymerization initiator is SO 2 .
Claim 6
Dependent Claim
15 words
The process according to claim 1 wherein the polymerization accelerator is tetra n-butyl ammonium sulfate.
Claim 7
Dependent Claim
16 words
The process according to claim 1 wherein the polymerization accelerator is methyl tri n-butyl ammonium sulfate.
Claim 8
Dependent Claim
15 words
The process according to claim 1 wherein the polymerization accelerator is tetra n-butyl ammonium bisulfate.
Claim 9
Dependent Claim
16 words
The process according to claim 1 wherein the polymerization accelerator is methyl tri n-butyl ammonium bisulfate.
Claim 10
Dependent Claim
70 words
The process of agitating at a critical point during the anionic polymerization of 2-pyrrolidone, said critical point being the brief period in which a friable gel is formed and before this gel becomes a tough cake, the friable gel being formed as a result of adding to the polymerization mixture a polymerization accelerator selected from the group consisting of quaternary ammonium sulfates and bisulfates, whereby a particulate polypyrrolidone is formed.
Claim 11
Dependent Claim
70 words
The process of agitating at a critical point during the anionic polymerization of 2-pyrrolidone, said critical point being the brief period in which a friable gel is formed and before this gel becomes a tough cake, the friable gel being formed as a result of adding to the polymerization mixture a polymerization accelerator selected from the group consisting of quaternary ammonium sulfates and bisulfates, whereby a particulate polypyrrolidone is formed.
References Cited (Backward Citations)
US2638463A
Cited
US2739959A
Cited
US2809958A
Cited
US2973343A
Cited
US3174951A
Cited
US3069392A
Cited
US2999852A
Cited
US3060153A
Cited
US3213066A
Cited
US3721652A
Cited
US3835100A
Cited
US4017465A
Cited
US4098774A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-07-27 | 1985-01-26 | 1985-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-27 | 1989-01-26 | 1989-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-27 | 1993-01-26 | 1993-07-28 | $7700.00 | Window Closed / Lapsed |