Continuous process for the concentration of W/O-emulsions by evaporation
AssigneeBayer Aktiengesellschaft
InventorsGerd Goldmann, Georg Spott, Christian Frohlich
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Abstract
The continuous process makes it possible to reduce the water content of polymers to minor residual levels (ppm) by adding to a W/O-emulsion an extractant which is subsequently evaporated with the oil.
Claims4
A continuous process for the concentration by evaporation of W/O-emulsions of the type accumulating in the emulsion polymerization of ethylenically-unsaturated, water-soluble monomers, comprising precluding polymer precipitation on the heat exchange surfaces of a helical multiphase flow tube with at least two phase streams by converting a W/O-emulsion having a water content of more than 25% by weight and a polymer content of from 28 to 40% by weight in vacuo at temperatures of from 80.degree. to 140.degree. C. into a non-aqueous polymer dispersion in oil having a residual water content adhering to the polymer of less than 14% by weight (based on polymer) and a polymer content of from 45 to 65% by weight.
Dependencies are inferred from the claim text.