CORE-SHELL SILICA AND METHOD FOR PRODUCING IT

摘要

To provide a core-shell silica having a high sphericity and a narrow particle distribution and a method for easily producing the core-shell silica. A method for producing a core-shell silica, which comprises a step of dispersing substantially non-porous silica core particles having a sphericity of at least 0.8 and a coefficient of variation of at most 0.2 in a dispersion medium containing an alcohol and water in the presence of a surfactant to prepare a dispersion; a step of adding a silica material to the dispersion and reacting the silica material under a condition of pH of from 8 to 13 to form a shell precursor containing silica and the surfactant on the surface of each silica core particle; and a step of removing the surfactant from the shell precursor to form a porous shell.