MOLECULAR SILICA SOLS AS NEW SILICA FORM A METHOD OF PREPARATION THEREOF Russian patent published in 1999 - IPC

FIELD: inorganic syntheses. SUBSTANCE: new silica form has general formula {Si₂O_x(OH)_y}_n, wherein x=3-3.8, y=0.4-2, n=40-20000, and particle size 3-60 nm, and can exist in dissolved state in anhydrous organic solvent selected from group including dioxan, acetone, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, ethylacetate, and butyl acetate. Preparation method includes formation of molecular structure by hydrolysis of superbranched polyethoxysiloxane in solvating solvent at concentration 0.5-20% followed by intramolecular cyclization of product under boiling conditions in presence of acid accompanied by distilling off water with organic solvent until conversion of ethoxyl groups is completed. New form is soluble in anhydrous organic solvent. Depending on product application areas, solution containing silica with specified characteristics (particle size 3-60 nm) can be obtained by varying process parameters. EFFECT: enabled process control. 5 cl, 4 dwg, 4 ex