Patent US3992562A successfully refreshed from Google Patents.
US3992562A
Expired / Lapsed
US
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Manufacture of insoluble and only slightly water-swellable polymers of N-vinyl lactams of improved adsorptivity
Assignee: BASF SE
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Filing: 1975-07-07
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Granted: 1976-11-16
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Expires: 1995-07-07
Abstract
Abstract Manufacture of insoluble polyvinyl lactams by polymerization in the absence of oxygen and in the presence of sulfur compounds having a functionality of less than 6.
Inventors
- 👤 Walter Denzinger
- 👤 Ernst Hofmann
- 👤 Karl Herrle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:20
CPC Classifications
A; A23; A23L; A23L2/00; A23L2/70; A23L2/80; B; B01; B01J; B01J20/00; B01J20/22; C; C08; C08F; C08F26/00; C08F26/06; C12; C12H; C12H1/00; C12H1/02; C12H1/04; C12H1/0416; C12H1/0424
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
122 words
A process for the manufacture of insoluble and only slightly swellable homopolymers of an N-vinyl lactam or copolymers of two or more vinyl lactams selected from the group consisting of N-vinyl pyrrolidone, N-vinyl caprolactam and N-vinyl piperidone which comprises: polymerizing the vinyl lactam or the mixture of vinyl lactams in a dilute aqueous solution of said lactam or lactams at a pH of 6 to 10 with the exclusion of oxygen, said polymerization taking place in the presence of a. divinyl ethylene urea, and b. from 0.05 to 2% by weight, based on the vinyl lactam of at least one sulfur compound selected from the group consisting of sodium sulfide, sodium sulfite, sodium pyrosulfite, sodium dithionate, sodium sulfoxylate and sodium formaldehyde sulfoxylate.
Claim 2
Dependent Claim
122 words
A process for the manufacture of insoluble and only slightly swellable homopolymers of an N-vinyl lactam or copolymers of two or more vinyl lactams selected from the group consisting of N-vinyl pyrrolidone, N-vinyl caprolactam and N-vinyl piperidone which comprises: polymerizing the vinyl lactam or the mixture of vinyl lactams in a dilute aqueous solution of said lactam or lactams at a pH of 6 to 10 with the exclusion of oxygen, said polymerization taking place in the presence of a. divinyl ethylene urea, and b. from 0.05 to 2% by weight, based on the vinyl lactam of at least one sulfur compound selected from the group consisting of sodium sulfide, sodium sulfite, sodium pyrosulfite, sodium dithionate, sodium sulfoxylate and sodium formaldehyde sulfoxylate.
Claim 3
Dependent Claim
16 words
A process as set forth in claim 1, wherein the vinyl lactam polymerized is vinyl pyrrolidone.
Claim 4
Dependent Claim
42 words
A process as set forth in claim 1, wherein the vinyl lactams copolymerized are vinyl pyrrolidone and from 5 to 100% by weight, based on vinyl pyrrolidone, of another vinyl lactam selected from the group consisting of N-vinyl caprolactam and N-vinyl piperidone.
Claim 5
Dependent Claim
19 words
A process as set forth in claim 1, wherein polymerization is carried out at from 50° to 100° C.
Claim 6
Dependent Claim
28 words
A process as set forth in claim 1 wherein the amount of divinyl ethylene urea is from about 0.5 to 10% by weight of said lactam or lactams.
Claim 7
Dependent Claim
17 words
A process as set forth in claim 1 wherein said pH range is from 7 to 9.
Claim 8
Dependent Claim
24 words
A process as set forth in claim 1 wherein the amount of said sulfur compound or compounds is from 0.1 to 0.5% by weight.
References Cited (Backward Citations)
US2927913A
Cited
US2938017A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-11-16 | 1980-05-17 | 1980-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-16 | 1984-05-17 | 1984-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-16 | 1988-05-17 | 1988-11-16 | $7700.00 | Window Closed / Lapsed |