US4180633A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of insoluble polyvinylpyrrolidone
Assignee: ISP Investments LLC
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Filing: 1978-08-23
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Granted: 1979-12-25
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Expires: 1998-08-23
Abstract
Abstract Insoluble cross-linked homopolymers of vinylpyrrolidone or copolymers of vinylpyrrolidone are prepared by reaction of the soluble homopolymer or copolymer with certain acid chlorides at a temperature between 75° C. and about 140° C., to obtain a precipitate. Alternately, the insoluble product may be prepared by heating a partial amide chloride of a homopolymer or copolymer of vinylpyrrolidone.
Inventors
- 👤 Kenneth W. Dixon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:59
CPC Classifications
C; C08; C08F; C08F8/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
65 words
A process for the preparation of insoluble homopolymers or copolymers of vinylpyrrolidone which comprises refluxing uncross-linked polyvinylpyrrolidone or an uncross-linked copolymer of vinylpyrrolidone with an acid chloride selected from the group consisting of phosgene, and oxalyl chloride in a liquid medium at a temperature between about 75° and about 140° C., to obtain a precipitate of cross-linked polyvinylpyrrolidone or of a cross-linked copolymer of vinylpyrrolidone.
Claim 2
Dependent Claim
65 words
A process for the preparation of insoluble homopolymers or copolymers of vinylpyrrolidone which comprises refluxing uncross-linked polyvinylpyrrolidone or an uncross-linked copolymer of vinylpyrrolidone with an acid chloride selected from the group consisting of phosgene, and oxalyl chloride in a liquid medium at a temperature between about 75° and about 140° C., to obtain a precipitate of cross-linked polyvinylpyrrolidone or of a cross-linked copolymer of vinylpyrrolidone.
Claim 3
Dependent Claim
18 words
A process according to claim 1 in which the liquid medium is a solvent for the acid chloride.
Claim 4
Dependent Claim
22 words
A process according to claim 2 in which the solvent is also a solvent for the polyvinylpyrrolidone or the copolymer of vinylpyrrolidone.
Claim 5
Dependent Claim
13 words
A process according to claim 1 in which the acid chloride is phosgene.
Claim 6
Dependent Claim
17 words
A process according to claim 1 in which the reaction temperature is from 90° to 120° C.
Claim 7
Dependent Claim
14 words
A process according to claim 1 in which the acid chloride is oxalyl chloride.
Claim 8
Dependent Claim
8 words
The product of the process of claim 1.
Claim 9
Dependent Claim
8 words
The product of the process of claim 4.
Claim 10
Dependent Claim
8 words
The product of the process of claim 6.
References Cited (Backward Citations)
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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) | 1982-12-24 | 1983-06-25 | 1983-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-24 | 1987-06-25 | 1987-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-24 | 1991-06-25 | 1991-12-25 | $7700.00 | Window Closed / Lapsed |