Patent ID: 6576704
Filing Date: 2003-06-10
Classification: C08F

Abstract:
A method for continuous treatment of a saponified ethylene-vinyl acetate copolymer (A) with acid(s) (B) and/or salt(s) thereof (C) which comprisescontinuously feeding to a column reactor from the top a saponified ethylene-vinyl acetate copolymer (Aâ€²) in pellet form, which contains incorporated therein the acid(s) (B) and/or salt(s) (C), wherein at least part of said acid(s) (B) and/or salt(s) (C) is a boric acid or its salt, simultaneously continuously feeding an aqueous solution of the acid(s) (B) and/or salt(s) (C), wherein at least part of said acid(s) (B) and/or salt(s) (C) is boric acid or its salt, from the bottom of the reactor to thereby effect a countercurrent contact of (Aâ€²) with the aqueous solution of (B) and/or (C), continuously withdrawing the excess of the aqueous solution of acid(s) (B) and/or salt(s) (C) from the reactor top, and continuously withdrawing the treated saponified ethylene-vinyl acetate copolymer from the reactor bottom.