Patent ID: 8623312

Claim:
A process for producing a dispersion of hollow fine SiO 2 particles in a dispersion medium, comprising: reacting a precursor of SiO 2 at a pH higher than 8 in the presence of fine ZnO particles in a dispersion medium such that a dispersion of fine particles comprising the fine ZnO particles covered with SiO 2 is obtained; dissolving the fine ZnO particles with an acidic cation exchange resin by adding the acidic cation exchange resin to the dispersion of fine particles in an amount which makes a total exchange capacity of the acidic cation exchange resin within a range of from 1.1 to 5 times an amount of zinc ions generated in the dispersion of fine particles, adjusts the pH to within a range of from 2 to 8, and adsorbs the zinc ions; and separating the acidic cation exchange resin by solid-liquid separation after the fine ZnO particles are dissolved such that the dispersion of hollow fine SiO 2 particles is obtained without separation of the zinc ions by ultrafiltration.