POWDER OF SAPONIFIED ETHYLENE-VINYL ACETATE COPOLYMER AND ITS USE

摘要

PURPOSE:To prepare the subject powder which gives an aq. dispersion having an excellent stability in standing and a low viscosity even at a high concn. by specifically treating a specific saponified ethylene-vinyl acetate copolymer. CONSTITUTION:The objective powder is prepd. by dissolving a saponified ethylene-vinyl acetate copolymer having an ethylene content of 20-60mol% and a degree of saponification of at least 90mol% in a mixture of water and a 1-4C alcohol under heating to give a soln. contg. 1-20wt.% the copolymer, cooling the soln. to precipitate the copolymer, adding an aliph. ketone (e.g. acetone) to the soln. contg. the precipitate under stirring to give a stable dispersion, and drying the dispersion to increase the content of the precipitate to 50wt.% or higher.