Title: Pyrogenic SiO2 particles and its producing method
Application Number: 02143977 Application Date: 2002.09.28
Publication Number: 1408642 Publication Date: 2003.04.09
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: C01B33/18;C08G77/02
Applicant(s) Name: Nippon Shokubai Co., Ltd. Address:
Inventor(s) Name: Oishi hideki;Kiyomizu Shuji;Irikuchi Jiro
Attorney & Agent: xu xiaoqin
Abstract:
    Provided is a calcined silica particle and a manufacturing method of the same, the calcined silica particle having a low hygroscopicity, and a narrow range of particle size distribution, and substantially even particle diameter, and containing little of large-diameter fused aggregation of the particulates of the calcined silica particle. A silica particle is obtained by hydrolyzing and condensing a hydrolyzable silicon compound in an organic solvent containing water, for example, at a reaction temperature ranging from 0 DEG C. to 50 DEG C., and then dried. Then, the silica particle is calcined at a temperature ranging from 1000 DEG C. to 1200 DEG C. It is preferable that the organic solvent contains the silicon compound in a range between 0.05 to 1.2 mol/L, the water in a range between 2.0 to 25.0 mol/L, and a catalyst in a range between 0.8 to 9.4 mol/L. The calcined silica particle has an average particle diameter ranging between 0.04 mum and 5.0 mum; a standard deviation of the average particle diameter of 1.3 mum or less; a moisture absorption amount of 0.2 wt % or less, measured after the calcined silica particle is kept for 1 day in an environment at 30 DEG C. and at 90% relative humidity; and a content of a fused aggregation of the calcined silica particle of 0.02 wt % or less, the fused aggregation having a particle diameter of 20 mum or more.
Time: 9
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