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US 4,053,696 AGranted
Manufacture of vinylpyrrolidone polymers
AssigneeBASF SE
InventorsKarl Herrle, Hermann Gausepohl, Wolfgang Schwarz
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Abstract
A process for the continuous manufacture of vinylpyrrolidone polymers of low K values, wherein vinylpyrrolidone, with or without comonomers copolymerizable therewith, is polymerized in organic solvents at elevated temperatures and superatmospheric pressures in the presence of a source of free radicals.
Claims8
A process for the continuous manufacture of polyvinylpyrrolidone having a K value of from 10 to 35 which comprises:
- continuously polymerizing a monomer consisting essentially of vinylpyrrolidone in at least one continuous polymerization zone at a temperature of from 100.degree. to 300.degree. C., in the presence of from 0.1 to 5% by weight, based on said monomer, of a free radical initiator selected from the group consisting of dicumyl peroxide, di-tert.-butyl peroxide and 2,2di-tert.-butyl peroxybutane, and in an organic solvent selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, dioxane, tetrahydrofuran, chloroform, methylene chloride, tetrachloroethane, hexachloroethane, xylene, cumene, alkylbenzenes or mixtures thereof, said continuous polymerization being carried out at a pressure greater than 1 bar and within a residence time in the polymerization zone of about 3 to 120 minutes.
Dependencies are inferred from the claim text.