METHOD OF PREPARING HYDROPHOBIC ORGANOPHILIC SILICA Russian patent published in 2000 - IPC

FIELD: chemical industry. SUBSTANCE: described is method of preparing hydrophobic organophilic silica. Method comprises chemical modification of silica surface during mechanical agitation and at elevated temperature. Modification is carried out by using compounds of general formula: or or wherein n is 1-3; m is 1-2; R is H, methyl, ethyl, Cl is methyl, propyl, phenyl; R′ is OCH₃OC₂H₅ Hal is Cl, Br or I: R″ is vinyl, allyl, methoxy, ethoxy. Original silica is subjected to hydroxylation with water vapor. Modification with compounds of formula: or is carried out in the presence of volatile acids. EFFECT: wider range of modifiers which make it possible to carry out chemical grafting of hydrocarbon, radicals and polymerization of compounds in surface layer. 3 cl, 3 ex, 1 tbl