Method For Producing Aqueous Ethylene/Vinyl Alcohol Based Copolymer Dispersion

Abstract

It is the object of the present invention to provide a method of producing, in an industrially advantageous manner, an ethylene/vinyl alcohol copolymer aqueous dispersion which has a high concentration and is excellent in long-term storage stability and in which the resin particles in the aqueous dispersion obtained are small in particle diameter. The present invention is a method of producing an ethylene/vinyl alcohol copolymer aqueous dispersion, which comprises: (1) a step of dissolving an ethylene/vinyl alcohol copolymer in a mixed solvent comprising 5 to 65% by weight of water and 35 to 95% by weight of a water-soluble organic solvent, with heating, (2) a step of cooling a solution obtained in said step to precipitate the ethylene/vinyl alcohol copolymer, (3) a step of reducing a concentration of the water-soluble organic solvent in said mixed solvent to a level lower than 35% by weight relative to the total amount of the water and water-soluble organic solvent by adding water, and (4) a step of distilling off said water-soluble organic solvent.

Dependencies are inferred from the claim text.