METHOD OF PRODUCING ETHYLENE-VINYL ACETATE COPOLYMER AND SAPONIFIED PRODUCT THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a method of producing ethylene-vinyl acetate copolymer and saponified product thereof that can control the defective appearance (particularly discoloration on molding) by improving the vinyl acetate-covering step. SOLUTION: The alcoholic solvent to be blown into the reaction system for recovering vinyl acetate is subjected to the deoxygenation treatment whereby the oxygen concentration in the alcohol solvent is reduced to <=60 ppm. The treated alcoholic solvent is blow in the form of vapor to recover vinyl acetate from the reaction mixture after the copolymerization of ethylene and vinyl acetate. Thus, the molded products of saponified ethylene-vinyl acetate copolymer can be inhibited from discoloration with oxygen.