PRODUCTION OF VINYL CHLORIDE POLYMER

PURPOSE:To obtain the titled polymer having a high bulk density, a low fish eye content and excellent heat stability, by suspension-polymerizing a vinyl chloride monomer in an aqueous medium containing an oil-soluble nonionic surfactant and a specified polymer. CONSTITUTION:100pts.wt. polymerizable unsaturated carboxylic acid compound (e.g., acrylic acid) is reacted with 0.05-10pts.wt. compound having at least two polymerizable ethylenically unsaturated double bonds in the molecule (e.g. divinylbenzene) as a crosslinking agent in the presence of a polymerization initiator to obtain a partially crosslinked polymer of the polymerizable unsaturated carboxylic acid component. 100pts.wt. vinyl chloride or a mixture based thereon is suspension-polymerized in the presence of an oil-soluble radical polymerization initiator in an apparatus coated with a scale inhibitor and containing an aqueous medium containing 0.01-2pts.wt. above produced polymer, 0.05-1pt.wt. oil-soluble nonionic surfactant (e.g., sorbitan monostearate) and, optionally, 0.1wt% or below water-soluble basic substance.