PRODUCTION OF VINYL CHLORIDE POLYMER

PROBLEM TO BE SOLVED: To prevent the outbreak of scale on the inside wall, etc., of a polymerization reactor in radical polymerization of vinyl chloride monomer. SOLUTION: A coating of a polycondensation product of ketone.pyrogallol or its oxide is previously given on inside wall of a polymerization reactor, an agitator and a baffle, etc., in case of polymerization of vinyl chloride monomer or vinyl chloride monomer mixture consisting of other copolymerizable monomer in an aqueous medium. The polycondensation product of ketone.pyrogallol is obtained by condensing three components such as acetone, methyl ethyl ketone with pyrogallol, the amount of the unit(A) based on acetone and the unit(B) based on methyl ethyl ketone is preferably in the range of (A)/(B)=30-70 mole %/70-30 mole %, based on the total of them. The coating is carried out by spray method, etc., in an amount of 0.001-5g/m .