METHOD FOR MAKING INORGANIC POWDER HYDROPHOBIC

摘要

PROBLEM TO BE SOLVED: To provide a method for making inorganic powder hydrophobic through a short time at a moderate temperature by using a proper amount of relatively economical treatment agent. SOLUTION: An inorganic powder is treated by a silylation agent in the presence of a third reagent selected from groups of Brϕnsted acids and linear phosphorus nitride halides. As the inorganic powder, fumed silica is preferable; as the Brϕnsted acids, ones having 120 deg.C or lower boiling point under atmospheric pressure can be usable and formic acid is preferable; and as the linear phosphorus nitride halides, a linear phosphorus nitride chloride is preferable.