Degussa Aktiengesellschaft

Nippon Aerosil Co., Ltd.

Evonik Degussa Gmbh

Hitoshi Kobayashi

Kai Schumacher

Hirokuni Shirono

Naruyasu Ishibashi

Masamichi Murota

Paul Brandl

Pyrogenically produced silicon dioxide powder in the form of aggregates of primary particles having a BET surface area of 300&#xb1;25 m/g, wherein the aggregates display an average surface area of 4800 to 6000 nm, an average equivalent circle diameter (ECD) of 60 to 80 nm and an average circumference of 580 to 750 nm. It is produced by a pyrogenic process in which silicon tetrachloride and a maximum of up to 40 wt. % of a second silicon component comprising HSiCl, HSiCl, HSiCl, CHSiCl, (CH)SiCl, (CH)SiCl and/or (n-CH)SiClare 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 1390 to 1450&#xb0; C. is obtained. It can be used as a filler.

Pyrogenically produced silicon dioxide powder

A fumed-silica, which can make a slurry having sufficient wettability to a polar liquid, excellent dispersibility, and low viscosity even in the high concentration, and a slurry thereof. A fumed-silica and its slurry are provided, wherein the water content is controlled so that a weight loss after drying Y, and a dynamic wetting rate to water Z, have specified values.

Low viscosity-increment fumed-silica and its slurry

Growing community of inventors

Yokkaichi, Japan

Hitoshi Kobayashi