Verfahren zur Herstellung von verseiften Äthylen-Vinylacetat-Copolymeren

A method for producing a saponified ethylene-vinyl acetate copolymer, which comprises washing chips of a saponified ethylene-vinyl acetate copolymer. In this method, the chips containing impurities and methanol are introduced into a washing column through an upper portion thereof; water is introduced into the washing column through a lower portion thereof; while the methanol concentration in the solution in the upper portion of the column is maintained in the range of 25 to 45 wt % and the chips are allowed to fall (i.e. sink) from the upper portion of the column, methanol and water with at least a part of the impurities are discharged from the column through an upper portion thereof; and the chips are taken out of the column through a lower portion thereof with water that contains methanol in a lower concentration than the methanol concentration in the solution in the upper portion of the column. According to this method, a saponified ethylene-vinyl acetate copolymer is produced efficiently and safely, and visual imperfections are inhibited when the saponified copolymer is formed into a molded product such as a film.