Abstract: The surface characteristics of dispersed particles such as vinyl resins are changed through the use of an anode electrolyte in an electrofilter. Accordingly, the properties of intermediate and final products made from these resins such as plastisols and fused films or coatings can be favorably changed. Properties which are altered include plastisol viscosity, film clarity, and foamability.

Abstract: A process for the removal of water from dispersed particles such as vinyl resins uses electrofiltration to yield a high total solids content wetcake. A final dryer such as a fluid energy dryer is used to yield a dry, finely divided resin or polymer. Accordingly, the need for various spray drying methods accompanied by subsequent harsh grinding steps are eliminated. Substantial energy cost savings are realized and the need for coagulation additives are eliminated as well as the necessary removal and neutralization of undesirable residues.

Abstract: There is disclosed a process of preparing vinyl dispersion resins by conducting the polymerization reaction of the vinyl monomer or monomers in an aqueous medium in the presence of a polymerization initiator or catalyst and an emulsifier or emulsifier system to form a vinyl resin latex, which is then subjected to an ultrafiltration step by forcing the same through a semipermeable membrane leaving behind the polymer particles and reusing the permeate, which contains dissolved monomer(s) and emulsifier, in the further production of vinyl resin latices. Unexpectedly, further use of the permeate substantially reduces polymer buildup in the reactor and since the ultrafiltration step increases the polymer particle concentration in the latex, considerable heat energy is saved in the spray-drying step.

Abstract: The invention relates to the production of vinyl dispersion or paste resins by means of the emulsion polymerization process and the recovery of the resins from the polymer latices produced thereby. In the process, the polymer latex is first carefully coagulated to yield a fast filtering sludge, the sludge is passed to a pressure filter to separate a high solids, friable polymer wetcake from the serum, the wetcake is rinsed with proper agents to neutralize the same and remove undesirable residues, pressure in the filter is applied to the rinsed wetcake to increase the solids content thereof, the wetcake is then broken into particles and friable agglomerates, and thereafter said particles and agglomerates are dried and ground to proper size in one step in a fluid energy mill. Thus the spray drying and the subsequent harsh grinding steps are eliminated producing a superior product for plastisols.