Polymer scale preventive agent.

摘要

A polymer scale preventive agent for use in polymerization of a monomer having an ethylenically unsaturated double bond, comprising (A) a pyrogallol-acetone resin, and (B) at least one member selected from the group consisting of water-soluble polymeric compounds, colloidal silicas and alkali metal silicates. When a coating comprising the polymer scale preventive agent is formed on inner wall surfaces of a polymerization vessel and the polymerization is carried out by use of the vessel, deposition of polymer scale can be effectively prevented not only in the areas in the liquid phase inside the vessel but also in the vicinity of the interface between the gas phase and the liquid phase in the vessel. The polymeric product thus obtained can then be processed into sheets or other formed products which have few fish eyes and low initial coloration.