Process for preventing polymer scale using an alkaline solution of a condensation product of an aromatic dibasic acid dihydrazide and an aromatic tetracarboxylic acid anhydride

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 condensation product of (A) an aromatic dibasic acid dihydrazide compound, and (B) an aromatic tetracarboxylic acid anhydride. 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 and useful in producing a polymer that shows very few fish eyes and good whiteness when formed into sheets or the like.