Patent ID: 7947369

Claim:
Fine spherical thermoplastic resin particles produced by a method comprising the steps of: preparing a resin composition comprising: a matrix comprising a water-soluble material, and fine particles comprising a water-insoluble thermoplastic resin and being dispersed in the matrix, the fine particles and the matrix each being melted or softened in the resin composition; cooling and solidifying the resin composition under such conditions that the resin composition does not undergo deformation due to stress; and removing the water-soluble material by washing with water to thereby yield fine spherical particles comprising the water-insoluble thermoplastic resin, wherein the particles each have a major axis “a” and a minor axis “h”, and wherein 95% or more of the particles have a ratio “a/b” of “a” to “b” of 1.25 or less, wherein the water-soluble material is a material that moltens or softens at temperatures at which the water-insoluble thermoplastic resin is molten or softened, that can thereby be kneaded with the water-insoluble thermoplastic resin, and that separates from the water-insoluble thermoplastic resin into two phases in a molten or solidified state, wherein the fine spherical thermoplastic resin particles have an average particle diameter of 0.1 to 30 μm, and wherein a coefficient of variation of particle diameters of the fine spherical thermoplastic resin particles is 20% or less.