Process for polymerization with suppressed polymer scale formation

摘要

A polymer scale preventive agent for use in polymerization of a monomer having an ethylenically unsaturated double bond, comprising an alkaline solution containing: (A) a condensation product of (A-1) a condensate of acetone with a hydroxybenzene compound having at least two hydroxyl groups, and (A-2) an aldehyde compound; (B) an inorganic colloid; and (C) a water-soluble polymeric compound. This agent is used for forming a coating on the inner wall, etc. of a polymerization vessel. Such a vessel is effective in preventing polymer scale deposition, not only on the areas in the liquid-phase region but also on the areas around the interface between the gas and liquid phases in the vessel, and useful in producing a polymer that shows very few fish eyes and good whiteness when formed into sheets or the like.