Method of removing foam during polymerization of vinyl chloride polymers

摘要

The present invention provides a method of producing vinyl chloride polymers, including the steps of subjecting vinyl chloride monomer or a mixture of monomers containing vinyl chloride monomer to suspension polymerization reaction in an aqueous medium within a polymerization vessel equipped with a reflux condenser, and subsequently, after the completion of the polymerization reaction, recovering any unreacted monomer, wherein foam generated on the surface of the liquid phase inside the polymerization vessel is eliminated by discharging a high pressure water having a pressure of 20 kg/cm2 or more substantially linearly to the surface of the liquid phase. The high pressure water discharging is carried out at the polymerization step, particularly from the time when operation of the reflux condenser begins, and/or at the recovery step. A vinyl chloride polymer is thus obtained without the splashing of foam over the gaseous phase section of the polymerization vessel, regardless of whether the heat removal rate of the reflux condenser, or the recovery rate per unit time for the unreacted monomer are increased.