US3933766A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of insoluble and only sparingly swellable poly-N-vinylpyrrolidone-2 or copolymers of N-vinylpyrrolidone with other N-vinyllactams
Assignee: BASF SE
•
Filing: 1973-11-09
•
Granted: 1976-01-20
•
Expires: 1993-11-09
Abstract
Abstract Manufacture of insoluble poly-N-vinyl-pyrrolidone-2 or copolymers of N-vinylpyrrolidone-2 in the presence of a difunctional crosslinker by heating the reaction solution at temperatures above 80°C and completing the reaction at the boiling temperature of water.
Inventors
- 👤 Ernst Hofmann
- 👤 Karl Herrle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:11
CPC Classifications
C; C08; C08F; C08F20/00; C08F20/02; C08F20/52; C08F20/54; C08F20/60
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
88 words
A process for the manufacture of insoluble cross-linked and only sparingly swellable copolymers of N-vinylpyrrolidone-2 consisting essentially of: heating to at least 80°C monomeric N-vinylpyrrolidone-2 in an aqueous solution containing from 0.5 to 10% by weight, based on monomeric N-vinylpyrrolidone-2, of a cyclic acid amide containing at least 2 ethylenically unsaturated groups of which at least one is attached to an amide nitrogen atom to initiate the polymerization reaction of said N-vinyl-pyrrolidone-2 and said cyclic acid amide and thereafter completing the reaction at the boiling temperature of water.
Claim 2
Dependent Claim
88 words
A process for the manufacture of insoluble cross-linked and only sparingly swellable copolymers of N-vinylpyrrolidone-2 consisting essentially of: heating to at least 80°C monomeric N-vinylpyrrolidone-2 in an aqueous solution containing from 0.5 to 10% by weight, based on monomeric N-vinylpyrrolidone-2, of a cyclic acid amide containing at least 2 ethylenically unsaturated groups of which at least one is attached to an amide nitrogen atom to initiate the polymerization reaction of said N-vinyl-pyrrolidone-2 and said cyclic acid amide and thereafter completing the reaction at the boiling temperature of water.
Claim 3
Dependent Claim
19 words
A process as set forth in claim 1, wherein up to 50% of the N-vinylpyrrolidone-2 is replaced by N-vinylcaprolactam.
Claim 4
Dependent Claim
27 words
A process as set forth in claim 1, wherein the cyclic acid amide used is a compound selected from the group consisting of N,N'-divinylimidazolidone, N,N'-divinylhexahydropyrimidinone-2 and N-vinyl-3-ethylidene-pyrrolidone-2.
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) | 1979-01-19 | 1979-07-21 | 1980-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-19 | 1983-07-21 | 1984-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-19 | 1987-07-21 | 1988-01-20 | $7700.00 | Window Closed / Lapsed |