METHOD FOR PRODUCING PELLET OF PARTIALLY SAPONIFIED ETHYLENE-VINYL ACETATE COPOLYMER

PROBLEM TO BE SOLVED: To enhance appearance characteristics by suppressing discoloration or the like of a product of partially saponified ethylene-vinyl acetate copolymer by adding improvement to a saponifying step. SOLUTION: When the ethylene-vinyl acetate copolymer is saponified in an alcoholic solvent in the presence of an alkali catalyst, water which is excluded as much as possible heretofore as catalytic poison is supplied into the solvent so as to be 100 to 15,000 ppm to the copolymer. For example, when a methanol solution of the copolymer and a methanol solution of the catalyst are respectively introduced from a tower top part 2 and a tower top part 3 (further a tower middle part 4 if needed) of a tower system saponification reactor 10 and a methanol vapor is blown from a tower bottom part 5, water of the above concentration is supplied to the methanol solution of the catalyst. COPYRIGHT: (C)2011,JPO&INPIT