Polymerization of vinyl chloride in the presence of a catalyst solubilized prior to exposure to monomer

In a process for producing a vinyl chloride polymer or copolymer by suspension polymerization in the presence of a monomer-soluble catalyst and a suspension stabilizer, comprising carrying out the polymerization at a temperature of 45.degree.-75.degree. C. in the presence of 0.4-8.0% by weight of an ethylene/vinyl acetate copolymer having a vinyl acetate content of 38% to 55% by weight, and a viscosity number of 95-210 ml/g, measured in toluene in a concentration of 0.005 g/cm.sup.3 at 25.degree. C.;

• the improvement wherein the catalyst is dissolved in a reaction compatible solvent when added to the polymerization charge and wherein the suspension stabilizer comprises 0.05-1.5% by weight, based on the amount of monomer or monomer mixture, of a methylcellulose having a methoxy substitution degree of 22-34% and a viscosity of 10-5,000 m Pa s, measured in a 2% by weight aqueous solution and measured according to the Brookfield method at 20.degree. C. and 20 rpm, or a methylhydroxypropylcellulose with a methoxy substitution degree of 20-32% and a hydroxy-propoxy substitution degree of 2-9% and a viscosity of 25-5,000 m Pa s, measured in a 2% by weight aqueous solution using a Ubbelohde capillary viscometer at 20.degree. C.