Patent ID: 9327258
Filing Date: 2016-05-03
CPC Classification: A61K,A61Q,B01J,C01B,Y10T

Claim Text:
1. Porous silica-based particles formed from a plurality of fine silica primary particles, wherein the primary particles are spherical or non-spherical having an average particle diameter of 0.005 to 0.1 μm, wherein the porous silica-based particles are formed from bonding of the primary particles, the porous silica-based particles having an average particle diameter of 0.5 to 30 μm and having a surface smoothness of a level to such an extent that, when the entire surface of the porous silica-based particle is observed from a photograph thereof taken by a scanning electron microscope (SEM) with a magnifying power of 10,000, the number of foreign matter attached to the surface of the porous silica-based particle including foreign particles observed as white dots on the photograph per μm wherein, when a surface roughness value of the porous silica-based particle is given by measuring a difference between a circumscribed circle and an inscribed circle at a boundary of the porous silica-based particle observed from a photograph of a cross-section thereof taken by a transmission electron microscope (TEM) with a magnifying power of 100,000, the porous silica-based particles have a surface roughness value of not more than 20 nm, the porous silica-based particles have an oil absorption rate in a range of 20 to 300 ml/100 g, the porous silica-based particles have a pore volume in a range of 0.05 to 3.0 ml/g, the porous silica-based particles have a coefficient of variation (CV value) in a range of 5% to 50%, and the specific surface area of the particle is 97 to 320 m