US4520180A
Expired / Lapsed
US
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Polymerization of vinylpyrrolidone to various molecular weights using a single initiator system consisting essentially of t-Butylperoxypivalate
Assignee: ISP Investments LLC
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Filing: 1982-09-20
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Granted: 1985-05-28
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Expires: 2002-09-20
Abstract
Abstract Vinylpyrrolidone is polymerized using free radical initiator consisting essentially of t-Butylperoxypivalate and preferably in solvent consisting essentially of water, isopropyl alcohol, sec. butyl alcohol or mixtures thereof.
Inventors
- 👤 Eugene S. Barabas
- 👤 James R. Cho
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:50
CPC Classifications
C; C08; C08F; C08F26/00; C08F26/06; C08F26/10
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
25 words
Process for making polyvinylpyrrolidone homopolymer which comprises polymerizing N-vinylpyrrolidone monomer in a reaction zone in the presence of free radical initiator consisting essentially of t-Butylperoxypivalate.
Claim 2
Dependent Claim
25 words
Process for making polyvinylpyrrolidone homopolymer which comprises polymerizing N-vinylpyrrolidone monomer in a reaction zone in the presence of free radical initiator consisting essentially of t-Butylperoxypivalate.
Claim 3
Dependent Claim
27 words
Process according to claim 1 wherein the polymerization is carried out in solvent consisting essentially of water or isopropyl alcohol or sec. butyl alcohol or mixtures thereof.
Claim 4
Dependent Claim
13 words
Process according to claim 2 wherein the solvent consists essentially of isopropyl alcohol.
Claim 5
Dependent Claim
12 words
Process according to claim 2 wherein the solvent consists essentially of water.
Claim 6
Dependent Claim
17 words
Process according to claim 2 wherein the solvent consists essentially of a mixture of isopropanol and water.
Claim 7
Dependent Claim
20 words
Process according to claim 5 wherein the alcohol is removed by distillation following completion of the polymerization of the N-vinylpyrrolidone.
Claim 8
Dependent Claim
21 words
Process according to claim 3 wherein following polymerization of the N-vinylpyrrolidone alcohol is removed by distillation with simultaneous addition of water.
Claim 9
Dependent Claim
30 words
Process according to claim 2 wherein the polymerization is carried out at a temperature between about 40° and about 150° C. and a pressure between about 0 and 150 psig.
Claim 10
Dependent Claim
49 words
Process according to claim 8 wherein: (a) the solvent is a mixture of isopropyl alcohol and water containing between about 40 and about 100 wt % water, (b) t-Butylperoxypivalate is present in the reaction zone in an amount between about 0.1% and about 5 wt % based on monomer.
Claim 11
Dependent Claim
23 words
Process according to claim 2 wherein t-Butylperoxypivalate is used in an amount between about 0.1 and about 5 wt % based on monomer.
Claim 12
Dependent Claim
45 words
Process according to claim 10 wherein the polymerization is carried out at a temperature between about 100° and about 150° C. and a pressure between about 20 psig and about 150 psig to produce polyvinylpyrrolidone having a K value between about 10 and about 20.
Claim 13
Dependent Claim
45 words
Process according to claim 10 wherein the polymerization is carried out at a temperature between about 40° and about 100° C. and a pressure between about 0 psig and about 20 psig to produce polyvinylpyrrolidone having a K value between about 20 and about 100.
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) | 1988-05-27 | 1988-11-26 | 1989-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-27 | 1992-11-26 | 1993-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-27 | 1996-11-26 | 1997-05-28 | $7700.00 | Window Closed / Lapsed |