Patent US3862915A successfully refreshed from Google Patents.
US3862915A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for aqueous polymerization of N-vinylpyrrolidone utilizing finely divided suspension of water insoluble catalyst
Assignee: BASF SE
•
Filing: 1973-04-05
•
Granted: 1975-01-28
•
Expires: 1993-04-05
Abstract
Abstract Solutions of N-vinylpyrrolidone polymers can be prepared with particular advantage by polymerization of N-vinylpyrrolidone in an aqueous medium by adding the polymerization catalyst in portions or continuously to the monomer solution in the form of a finely divided suspension in an aqueous solution of Nvinylpyrrolidone polymer.
Inventors
- 👤 Micharl Fried
- 👤 Rolf Moeller
- 👤 Ludwig Zuern
- 👤 Erhard Stahnecker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:42
CPC Classifications
C; C08; C08F; C08F26/00; C08F26/06; C08F26/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
31 words
A process as claimed in claim 1 in which the aqueous solution of the monomer is heated to 60* to 150*C and then the suspension of the polymerization catalyst is introduced.
Claim 2
Dependent Claim
109 words
A process for the production of an aqueous solution of poly-N-vinylpyrrolidone by polymerization of N-vinylpyrrolidone in an aqueous solution at a temperature of from 60* to 120* C., which process comprises heating an aqueous solution of N-vinylpyrrolidone to a temperature of from 60* to 120*C. and then supplying continuously from 0.01 to 3 percent by weight (based on the amount of N-vinylpyrrolidone) of a water-insoluble polymerization catalyst forming free radicals in the form of a finely divided 10 to 30 percent by weight suspension in an aqueous 5 to 15 percent by weight solution of a poly-N-vinylpyrrolidone having a K value in aqueous solution of from 80 to 120.
Claim 3
Dependent Claim
140 words
A process for the production of an aqueous solutIon of poly-N-vinylpyrrolidone by polymerizing N-vinylpyrrolidone in an aqueous medium at a temperature of from 60* to 120*C., which process comprises heating an aqueous N-vinylpyrrolidone solution to a temperature of 60* to 120*C. and then supplying 0.01 to 3 percent by weight, based on the amount of N-vinylpyrrolidone, of a water-insoluble polymerization catalyst forming a free radicals in the form of a finely divided 10 to 30 percent by weight suspension in an aqueous 5 to 15 percent by weight solution of poly-N-vinylpyrrolidone having a K value in aqueous solution of from 80 to 120 by first adding from 5 to 20 percent by weight of the total amount of catalyst and then adding the remainder of the polymerization catalyst during the polymerization in one to ten portions to the polymerization mixture.
Claim 4
Dependent Claim
28 words
A process as claimed in claim 1 wherein said water-insoluble polymerization catalyst forming free radicals is a compound selected from the class consisting of peroxides, azobiscarbonitriles and azobiscarboxamides.
Claim 5
Dependent Claim
28 words
A process as claimed in claim 3 wherein said water-insoluble polymerization catalyst forming free radicals is a compound selected from the class consisting of peroxides, azobiscarbonitriles and azobiscarboxamides.
Claim 6
Dependent Claim
28 words
A process as claimed in claim 4 wherein said water-insoluble polymerization catalyst forming free radicals is a compound selected from the class consisting of peroxides, azobiscarbonitriles and azobiscarboxamides.
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) | 1978-01-27 | 1978-07-29 | 1979-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-27 | 1982-07-29 | 1983-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-27 | 1986-07-29 | 1987-01-28 | $7700.00 | Window Closed / Lapsed |