POLYVINYL ALCOHOL POLYMER, DISPERSANT FOR SUSPENSION POLYMERIZATION, VINYL CHLORIDE RESIN AND PRODUCTION METHOD OF THE RESIN

摘要

PROBLEM TO BE SOLVED: To provide a dispersant for suspension polymerization, which has sufficient water solubility/water dispersibility, improves a porosity of a vinyl chloride resin that is obtained when the dispersant is used as a dispersant for suspension polymerization, and gives no adverse influence on a particle diameter of the vinyl chloride resin, and to provide a vinyl chloride resin and a production method of the resin having a superior porosity by using the dispersant.;SOLUTION: A polyvinyl alcohol polymer is prepared by saponifying a polymer comprising vinyl acetate and an unsaturated carboxylic acid; and the polyvinyl alcohol polymer has a copolymerization amount of the unsaturated carboxylic acid of 0.15 mol% or more and 0.4 mol% or less, a polymerization degree ranging from 200 to 350, and a saponification degree of 30 mol% or more and 50 mol% or less. By using the above polyvinyl alcohol polymer as a dispersant for suspension polymerization, a vinyl chloride resin having a superior porosity is obtained.;COPYRIGHT: (C)2014,JPO&INPIT