PURPOSE: To obtain the titled resin capable of lowering the viscosity of a plastisol and improving the mechanical strength of the product, by adding an emulsifier to the system for the polymerization of vinyl chloride using an oil-soluble catalyst, after the initiation of polymerization or to the polymer obtained by the polymerization.
CONSTITUTION: The objective resin is prepared by the suspension (co)polymerization of vinyl chloride or its mixture with a copolymerizable monomer[e.g. vinyl acetate, (methyl) (meth)acrylate, etc.]in the presence of preferably 0.1W2 PHR of a polymeric suspension stabilizer[e.g. (partially saponified) polyvinyl alcohol]and an oil-soluble thermal-decomposition type radical generator (e.g. lauroyl peroxide). In the above process, an emulsifier (e.g. dodecylbenzenesulfonic acid sodium salt) is added to the polymerization system after the intiation of the polymerization, preferably after the conversion reaches 30%, or to the dried resin in an amount of 0.002W5PHR.
KAMETANI HIDEYUKI
AOISHI EIJI
