Method for rendering inorganic powder hydrophobic

摘要

Inorganic powder, preferably fumed silica, is rendered hydrophobic by treatment with a silylating agent in the presence of a third reagent selected from the group consisting of protonic acids, especially those having a boiling point at atmospheric pressure up to 120 DEG C., preferably formic acid, and linear phosphonitrilic halides, preferably linear phosphonitrilic chlorides.