| abstract |
(57) [Summary] [Problem] It is possible to stably maintain excellent hydrophobicity and fluidity, and it is a fluidizing agent for various organic and inorganic powders, a thickener such as a resin, and a reinforcing filler. To provide a hydrophobic silica powder useful as a powder. Kind Code: A1 A silica powder surface-treated with a polysiloxane and a trimethylsilylating agent, wherein the trimethylsilyl group has a surface area of 1 nm of the original silica powder of the silica powder. 0.3 to 1.5 pieces per 2 Polysiloxane is the original silica powder of the silica powder 100 A / 20 to A / 5 parts by weight (where A is the specific surface area (m 2 / g) of the raw silica powder) is applied to the parts by weight. |