US4235884A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the preparation of stable aqueous solutions of complexes of polyvinylpyrrolidone and of halogens and the solutions obtained thereby
Assignee: Individual
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Filing: 1979-03-05
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Granted: 1980-11-25
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Expires: 1999-03-05
Abstract
Abstract The invention relates to the chemical industry. A stable aqueous solution of a complex of polyvinylpyrrolidone and halogen is prepared by carrying out the following steps: (a) The halogen is put in solution in the presence of PVP in a solvent that solubilizes the two components, the said solvent having a boiling point lower than that of water, being insoluble in water, and forming no azeotrope with the latter; (b) The solution obtained is heated to react the PVP and the halogen; (c) The said solvent is displaced by addition of water brought to a temperature higher than the boiling point of the said solvent. These solutions are used as germicides and bactericides.
Inventors
- 👤 Nicolas Salkin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:33
CPC Classifications
A; A01; A01N; A01N59/00; A01N59/12
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
108 words
Method for preparation of a stable aqueous solution of a complex of halogen and polyvinylpyrrolidone (PVP) comprising the following steps: (a) halogen selected from the group consisting of chlorine, iodine and bromide is put in solution in the presence of PVP in a solvent which solubilizes the two components, the said solvent having a boiling point lower than that of water, being insoluble in water, and forming no azeotrope with the latter; (b) The solution obtained is heated to react the PVP and the halogen; (c) The said solvent is displaced by addition of water brought to a temperature higher than the boiling point of the said solvent.
Claim 2
Dependent Claim
108 words
Method for preparation of a stable aqueous solution of a complex of halogen and polyvinylpyrrolidone (PVP) comprising the following steps: (a) halogen selected from the group consisting of chlorine, iodine and bromide is put in solution in the presence of PVP in a solvent which solubilizes the two components, the said solvent having a boiling point lower than that of water, being insoluble in water, and forming no azeotrope with the latter; (b) The solution obtained is heated to react the PVP and the halogen; (c) The said solvent is displaced by addition of water brought to a temperature higher than the boiling point of the said solvent.
Claim 3
Dependent Claim
20 words
Method according to claim 1 in which the solvent is chosen from the group formed by methylene chloride and chloroform.
Claim 4
Dependent Claim
67 words
Method according to claim 1 in which the halogen is iodine, the solvent is methylene chloride, the solution of PVP and iodine is heated in a closed vessel to a temperature comprised between 60° and 65° C., the said solution is cooled to a temperature comprised between 40° and 42° C., and the methylene chloride is displaced by addition of water at a temperature of 42°-44° C.
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) | 1983-11-25 | 1984-05-26 | 1984-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-25 | 1988-05-26 | 1988-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-25 | 1992-05-26 | 1992-11-25 | $7700.00 | Window Closed / Lapsed |