Patent US2004366A successfully refreshed from Google Patents.
Patent US4058655A successfully refreshed from Google Patents.
US4058655A
Expired / Lapsed
US
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Manufacture of low molecular weight poly-N-vinylpyrrolidone-2
Assignee: BASF SE
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Filing: 1976-03-08
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Granted: 1977-11-15
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Expires: 1996-03-08
Abstract
Abstract Low molecular weight poly-N-vinyl-pyrrolidone-2 is prepared by polymerizing N-vinylpyrrolidone-2 at elevated temperature in the presence of organic peroxides which carry organic radicals on either side of the peroxide group.
Inventors
- 👤 Walter Denzinger
- 👤 Kurt Seelert
- 👤 Karl Herrle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 05:29
CPC Classifications
C; C08; C08F; C08F26/00; C08F26/06; C08F26/10
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
111 words
A process for the manufacture of homopolymers of N-vinylpyrrolidone-2 of low molecular weight having K values of less than 25 as measured by the method of H. Fikentscher, in 5 percent strength aqueous solution at 20° C, and said homopolymers having less than 0.1% residual monomer which comprises polymerizing said vinylpyrrolidone in an organic solvent at above 100° C. in the presence of an organic peroxide which carries an aliphatic or araliphatic radical, respectively of 1 to 8 or of 6 to 8 carbon atoms, on either side of the peroxide group, said vinylpyrrolidone as the monomer being gradually added during the polymerization within a period of 1 to 5 hours.
Claim 2
Dependent Claim
111 words
A process for the manufacture of homopolymers of N-vinylpyrrolidone-2 of low molecular weight having K values of less than 25 as measured by the method of H. Fikentscher, in 5 percent strength aqueous solution at 20° C, and said homopolymers having less than 0.1% residual monomer which comprises polymerizing said vinylpyrrolidone in an organic solvent at above 100° C. in the presence of an organic peroxide which carries an aliphatic or araliphatic radical, respectively of 1 to 8 or of 6 to 8 carbon atoms, on either side of the peroxide group, said vinylpyrrolidone as the monomer being gradually added during the polymerization within a period of 1 to 5 hours.
Claim 3
Dependent Claim
21 words
A process as claimed in claim 1, wherein the peroxide employed is dicumyl peroxide, di-tert.-butyl peroxide, tert.-butyl cumyl peroxide or 2,2-di-tert.-butyl-peroxybutane.
Claim 4
Dependent Claim
21 words
A process as claimed in claim 1, wherein from 0.1 to 6% by weight of peroxide, based on monomer, is employed.
Claim 5
Dependent Claim
26 words
A process as claimed in claim 1, wherein said vinylpyrrolidone as the monomer is gradually added together with the solvent and the peroxide during the polymerization.
Claim 6
Dependent Claim
18 words
A process as claimed in claim 1, wherein the polymerization temperature is above 100° up to 300° C.
Claim 7
Dependent Claim
17 words
A process as claimed in claim 1, wherein the polymerization temperature is about 120° to 200° C.
Claim 8
Dependent Claim
21 words
A process as claimed in claim 1, wherein the organic solvent has a boiling point of about 50° to 150° C.
Claim 9
Dependent Claim
13 words
A process as claimed in claim 1, wherein the organic solvent is isopropanol.
Claim 10
Dependent Claim
28 words
A process as claimed in claim 1, wherein the vinylpyrrolidone as the monomer is gradually added during the polymerization within a period of about 3 to 4 hours.
References Cited (Backward Citations)
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US3296231A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-11-14 | 1981-05-16 | 1981-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-14 | 1985-05-16 | 1985-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-14 | 1989-05-16 | 1989-11-15 | $7700.00 | Window Closed / Lapsed |