METHOD FOR PRODUCING ETHYLENE-VINYL ACETATE RESIN EMULSION

摘要

PROBLEM TO BE SOLVED: To provide a method for producing an ethylene-vinyl acetate resin emulsion with which the emulsion polymerization controllability is excellent with slight discoloration and the amount of the unreacted vinyl acetate monomer in the emulsion polymerization system can be reduced to <=0.2 wt.% with the result that formaldehyde is scarcely contained or not contained at all. SOLUTION: This method for producing the ethylene-vinyl acetate resin emulsion comprises carrying out emulsion polymerization of ethylene with vinyl acetate using a vinyl alcoholic polymer having >=70 mol% degree of saponification as a dispersing agent and a redox polymerization initiator composed of hydrogen peroxide, tartaric acid and/or its metal salt. The method is characterized as follows. The pH of the polymerization system is regulated to 3-7 and an iron compound is added to conduct the emulsion polymerization. Furthermore, hydroperoxides are added when the amount of the unreacted vinyl acetate monomer in the polymerization system is <=5 wt.%.