Surface-treated silica powder, package, storage method

Abstract

The surface-treated silica powder of the present invention comprises silica particles that have been surface-treated with a silane coupling agent, wherein the specific surface area of ​​the surface-treated silica powder, as determined by the BET single-point method based on nitrogen adsorption, is 0.8 m² / g or more and 5.0 m² / g or less, and the water vapor adsorption isotherm of the surface-treated silica powder, as determined by a gas adsorption capacity measuring device, has a water vapor adsorption capacity of 0.35 cm³ (STP) / g or less at a relative pressure of 0.9. A surface-treated silica powder of the invention contains silica particles that have been surface-treated with a silane coupling agent, and satisfies the following conditions: the specific surface area of ​​the surface-treated silica powder, measured by the single-point BET method using nitrogen gas adsorption, is at least 0.8 m2 / g but not more than 5.0 m2 / g, and in a water vapor adsorption isotherm for the surface-treated silica powder, measured using a gas adsorption measurement device, the amount of water vapor adsorption at a relative pressure of 0.9 does not exceed 0.35 cm3 (STP) / g.