PROCESS FOR PRODUCING SPHERICAL COMPOUND HARDENED MELAMINE RESIN PARTICLES

摘要

The present invention relates to a process for producing spherical composite cured melamine resin particles excellent in water resistance, in which colloidal silica is localized near the surface thereof, wherein the process makes possible to control particle size thereof in broad ranges from a submicron to micron order. Concretely, the present invention is a process for producing spherical composite cured melamine resin particles comprising (a) a step of reacting a melamine compound with an aldehyde compound in an aqueous medium under a basic condition in the presence of a suspension of colloidal silica having an average particle size of 5 to 70 nm to produce an aqueous solution of a precondensate of water-soluble melamine resin; and (b) a step of adding an acid catalyst to the aqueous solution produced in the step (a) to separate out spherical composite cured melamine resin particles, and further (c) a step of coating the surface of the spherical composite cured melamine resin particles with inorganic compound particles.