BigPatents India

Pyrogenically produced silicon dioxide powder in the form of aggregates of primary particles having a BET surface area of 90 ± 15 m2/g, wherein the aggregates display an average surface area of 10000 to 20000 nm2, an average equivalent circle diameter (ECD) of 90 to 130 nm and an average circumference of 1000 to 1400 nm. It is produced by a pyrogenic process in which silicon tetrachloride and a second silicon component comprising H3SiCl, H2SiCl2, HsiCl3, CH3SiCl3, (CH3)2SiCl2, and/or (CH3)3SiCl are mixed with primary air and a combustion gas and burnt into a reaction chamber, secondary air also being introduced into the reaction chamber, and the feed materials being chosen such that an adiabatic flame temperature of 1810 to 18900C is obtained. Dispersion containing the pyrogenically produced silicon dioxide powder. (FIG.nil)