Polymer scale preventive agent from naphthoquinone dye

摘要

A polymer scale preventive agent for use in polymerization of vinyl chloride monomer or a monomer mixture containing vinyl chloride monomer as a major component, comprising: (A) a naphthoquinone natural dye and (B) a polyvinyl alcohol with a saponification degree of at least 50 mol %. The polymer scale preventive agent is formed as coating on the inner wall, etc. of a polymerization vessel. Deposition of polymer scale can be always effectively prevented. Polymers with a high whiteness can be produced, and products formed from the polymer have only a small number of fish eyes.