Patent ID: 10125252

Abstract:
By first forming an emulsion in a system that separates into two phases which include a solution phase containing an ethylene-vinyl alcohol copolymer (A) as the main component and a solution phase containing a polymer (B) different from the ethylene-vinyl alcohol copolymer (A) as the main component when the copolymer (A), the polymer (B), and an organic solvent (C) having an SP value of 20 (J/cm3)1/2 to 30 (J/cm3)1/2 are dissolved and mixed together, and then causing the ethylene-vinyl alcohol copolymer (A) to precipitate as microparticles by bringing a poor solvent (D) of the ethylene-vinyl alcohol copolymer (A) into contact with the emulsion, it is possible to obtain ethylene-vinyl alcohol copolymer microparticles that have a narrow particle size distribution wherein the particle size distribution index in a dry-powder state is 2 or less, have a true spherical particle shape, and exhibit excellent re-dispersibility into liquid.