| 摘要 |
PURPOSE:To obtain inexpensively a high specific gravity granular vinyl chloride resin excellent in flow, etc., by adding a coagulating agent and a hydrophobic poor solvent to an aqueous vinyl chloride resin latex, agitating the mixture, heating the formed resin beads in the aqueous medium, separating the beads from the free water and drying them. CONSTITUTION:An aqueous vinyl chloride resin latex is produced by emulsion polymerization or fine suspension polymerization. A coagulating agent (e.g. calcium acetate) and a hydrophobic poor solvent (e.g. mineral spirit) are slowly added to the aqueous latex under agitation to form vinyl chloride resin beads. The resin beads are heated in the aqueous medium, separated from the free water by decantation or the like and dried to obtain a granular vinyl chloride resin. In this way, drying is performed after most of the water is removed from the aqueous vinyl chloride resin latex, so that the energy for drying can be reduced. |
