METHOD OF PREPARING HYDROPHOBIC DISPERSE MATERIAL Russian patent published in 1997 - IPC

FIELD: disperse materials. SUBSTANCE: essence of invention consists in activation of silicon dioxide or metal oxide by alkali metal carbonates under mechanical stirring and chemically modifying surface at elevated temperature with organoelemental compound with general formula Cl_4-nSiR_n where n = 1-3, R is methyl, ethyl, chloromethyl, or phenyl followed by chemical treatment with 0.5-1.0 wt % of compound selected from group: tetramethoxysilane, tetraethoxysilane, polymethyl(ethyl)siloxane oligomer, and polymethylsilazane oligomer. Chemical modification of disperse material is carried out at 20-200 C and disperse material to organoelemental modifier weight ratio (4- 15):1. According to invention, starting material is preliminarily dried to moisture content not higher than 1 wt %, and activation and surface modification are conducted for 30-120 min, evolved gas products being removed using inert gas or air blowing through alkali neutralizer. EFFECT: essentially simplified chemical modification process and 27-40 times reduced power consumption. 4 cl, 1 tbl