SURFACE-MODIFICATION PROCESS OF SILICA PARTICLE USING TRIALKOXYSILANE COMPRISING PHENYL GROUP OR ALKYL GROUP SUBSTITUTED BY FUNCTIONAL GROUP AND SILICA PARTICLE THEREBY

摘要

A noble process of preparing surface-modified silica particles by adding trialkoxysilane comprising a phenyl group or an alkyl group substituted by a functional group to the silica particles during the formation of silica particles is provided, and a method for improving hydrophobicity of the silica particles by acid-treating silica particles prepared by the method is provided. A process of preparing surface-modified silica particles comprises the steps of: (A) mixing 100 volume parts of alcohol with 8.8 to 16.3 volume parts of alkoxysilane to prepare a first solution; (B) mixing 100 volume parts of alcohol, 2.5 to 4.7 volume parts of ammonia water, and 27.0 to 50.2 volume parts of water to prepare a second solution; (C) mixing the first solution with the second solution, and agitating the mixed solution for 3 to 5 hours; (D) adding 2.7 to 5.0 mole parts of a compound of the formula, L3-Si-M, where L is an alkoxy group with 1 to 5 carbon atoms, and M is a phenyl group or an alkyl group with 1 to 10 carbon atoms of which hydrogen of a terminal is substituted for a halogen atom, a nitro group, a sulfone group, a hydroxyl group, an amine group, an aldehyde group, or a carboxyl group, to the mixed solution of the first and second solutions, and additionally agitating the mixture for 18 to 24 hours; and (E) separating solid and liquid from the formed silica particles. Further, a step (F) of adding the silica particles into the acidic solution and reacting the silica particles-added acidic solution for 18 to 36 hrs is additionally comprised in the process after the step (E).