| 摘要 |
PURPOSE:To produce porous PVC having a sharp particle diameter distribution, by suspension-polymerizing vinyl chloride in the presence of a sorbitan higher fatty acid ester and a water-soluble dispersant by using specific conditions. CONSTITUTION:To an aqueous medium vinyl chloride and 0.05-5wt% oleophilic sorbitan higher fatty acid ester (e.g., sorbitan monolaurate) as a dispersant are added, and the polymerization of the mixture is started at 40-70 deg.C in the presence of an oil-soluble radical polymerization catalyst (e.g., benzoyl peroxide) with agitation effected chiefly by recirculation. When the polymer conversion reaches 5-40%, 0.02-1wt% based on the vinyl chloride, water-soluble dispersant (e.g., partially saponified PVA) is added to the reaction system, and the polymerization of the system is brought to completion. EFFECT:It is possible to prevent polymer scale deposition on the inside wall of a polymerizer during polymerization.
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