PRODUCTION OF VINYL CHLORIDE RESIN POWDER FOR PASTE PROCESSING

PURPOSE:To provide a vinyl chloride resin powder for paste processing which is easily separated into individual particles and has a good dispersibility by mixing an aq. dispersion of a vinyl chloride resin with an org. fluid, stirring the mixture in the presence of a flocculant to form a flocculate of the resin, and separating the flocculate from the aq. phase. CONSTITUTION:The vinyl chloride resin powder is produced by adding an org. fluid (e.g. diisononyl phthalate) which is hardly sol. in water and does not dissolve nor swell a vinyl chloride resin to a continuous mixer installed in a pipe through which an aq. dispersion of a vinyl chloride resin for paste processing (e.g. a vinyl chloride homopolymer obtd. by emulsion or microsuspension polymn.) is flowing in an amt. of the fluid of 0.2-5 pts.wt. based on 100 pts.wt. vinyl chloride resin to form a mixture of the fluid and the resin, leading the mixture into a batch mixer where to stir it in the presence of a flocculant (e.g. aluminum polychloride) at 20-70 deg.C to form a flocculate of the resin (with an average particle size of 50-500mum), and separating the flocculate from the aq. phase.