POLYMERIZATION OF VINYL CHLORIDE-BASED MONOMER

PURPOSE:To carry out the subject polymerization with scale deposition on the inner wall of a polymerizer effectively prevented along with its persistency improved, by coating the inner wall, etc., of a polymerizer with a mixture of an alkali metal xanthate, polyethyleneimine and a dialdehyde. CONSTITUTION:Firstly, the surface(s) of the inner wall of a polymerizer and/or its attachment devices is(are) coated with a mixture of (A) an alkali metal xanthate (e.g., sodium ethylxanthate), (B) polyethyleneimine and (C) a dialdehyde (e.g., glyoxal). Thence, using the resultant polymerizer, vinyl chloride monomer or a mixture consisting mainly of vinyl chloride monomer is polymerized in an aqueous medium. A preferable coating treatment process is, e.g., that the components A, B and C are mutually mixed in a spray nozzle just before coating followed by spraying.