PRODUCTION OF POLYMERIC PARTICLE

PURPOSE:To efficiently obtain truly spherical monodispersed polymer particles having a specific particle diameter according to a simple process by slowly adding an aqueous dispersion of a polymerizable monomer and an aqueous solution of a water-soluble polymeric compound to an aqueous dispersion of seed particles. CONSTITUTION:A polymerizable monomer (preferably containing >=3wt.% polyfunctional vinylic monomer) is polymerized on seed particles while continuously or intermittently and slowly adding (B) an aqueous dispersion prepared by mixing 100 pts.wt. polymerizable monomer with 15-200 pts.wt. water, as necessary, 0.05-5 pts.wt. surfactant, 0.1-10 pts.wt. polymerization initiator (preferably an azo compound) and 0.02-10 pts.wt. polymerization inhibitor and (C) an aqueous solution of a water-soluble polymeric compound (preferably polyvinyl alcohol, etc.) in an amount of 0.5-50 pts.wt. based on 100 pts.wt. polymerizable monomer at 0.1-20wt.% concentration to (A) an aqueous dispersion obtained by mixing 100 pts.wt. water with 0.1-20 pts.wt. seed particles (preferably polymeric particles such as styrenic polymeric particles). Thereby, the objective polymeric particles having 0.5-50mum particle diameter are obtained.