US4128633A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing PVP-iodine complex
Assignee: ISP Investments LLC
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Filing: 1977-04-27
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Granted: 1978-12-05
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Expires: 1997-04-27
Abstract
Abstract In accordance with the present invention, there is provided herein an in situ process for making stable PVP-iodine complex having a high level of iodine power. The process of this invention is carried out by adding a predetermined amount of free water to a PVP suspension, and admixing iodine therewith to form the desired solid complex. The PVP suspension may be obtained by suspension polymerization of N-vinylpyrrolidone (VP) in a suitable solvent, and used directly for succeeding steps of the process.
Inventors
- 👤 Donald H. Lorenz
- 👤 Earl P. Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:16
CPC Classifications
A; A01; A01N; A01N59/00; A01N59/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
148 words
An improved in situ process of forming a PVP-iodine complex powder which is stable for prolonged periods of time at a high level of iodine power, but which requires a reduced amount of iodine to form said complex at said level which comprises the following sequence of steps in combination: (a) suspension polymerizing vinylpyrrolidone in a solvent in which said vinylpyrrolidone is miscible but in which PVP is insoluble to form a slurry of polyvinylpyrrolidone powder in said solvent, (b) adding free water to said slurry in an amount of about 1-10% by weight of said polyvinylpyrrolidone thereby to form polyvinylpyrrolidone powder having a predetermined concentration of water therein, and, (c) adding finely divided elemental iodine to said slurry in an amount of about 5-25% by weight based on the complex at a temperature of about 65-85° C. and for a time sufficient to form said desired complex.
Claim 2
Dependent Claim
148 words
An improved in situ process of forming a PVP-iodine complex powder which is stable for prolonged periods of time at a high level of iodine power, but which requires a reduced amount of iodine to form said complex at said level which comprises the following sequence of steps in combination: (a) suspension polymerizing vinylpyrrolidone in a solvent in which said vinylpyrrolidone is miscible but in which PVP is insoluble to form a slurry of polyvinylpyrrolidone powder in said solvent, (b) adding free water to said slurry in an amount of about 1-10% by weight of said polyvinylpyrrolidone thereby to form polyvinylpyrrolidone powder having a predetermined concentration of water therein, and, (c) adding finely divided elemental iodine to said slurry in an amount of about 5-25% by weight based on the complex at a temperature of about 65-85° C. and for a time sufficient to form said desired complex.
Claim 3
Dependent Claim
29 words
A process according to claim 1 wherein said water is added in an amount of about 5-8% by weight and said amount of iodine is about 10-20% by weight.
Claim 4
Dependent Claim
24 words
A process according to claim 2 wherein said reaction temperature is about 70°-75° C. and said reaction time is at least 1 1/2 hours.
Claim 5
Dependent Claim
18 words
A process according to claim 2 wherein said suspension polymerization is carried out in a saturated aliphatic hydrocarbon.
Claim 6
Dependent Claim
21 words
A process according to claim 4 wherein said saturated aliphatic hydrocarbon is selected from the group consisting of hexane and heptane.
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) | 1981-12-04 | 1982-06-05 | 1982-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-04 | 1986-06-05 | 1986-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-04 | 1990-06-05 | 1990-12-05 | $7700.00 | Window Closed / Lapsed |