Amorphous silica particles having a double structure, process for producing the same and use

摘要

The present invention provides the amorphous silica particles having a double structure of a core of the dense amorphous silica and a shell of the bulky amorphous silica, having a volume-based median diameter of from 1 to 5 mu m and containing not more than 10% by volume of fine particles having a particle diameter of not larger than 0.5 mu m. The amorphous silica particles of the double structure have constant particle diameters not only in the powdery state but also in a state where they are blended in a coating material or in a resin, without developing fine particles, exhibit excellent delustering action and antiblocking action, exhibit decreased abrading property, and exhibit excellent resistance against scars or abrasion.