| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide porous silica based particles having excellent surface smoothness, and a cosmetic obtained by being blended with the porous silica based particles.SOLUTION: Provided is porous silica based particles in which the average particle diameter lies in the range of 0.5 to 30μm, and having surface smoothness in such a manner that the number of micro-particles present perμmof the plane obtained by capturing the whole surfaces of the particles with a scanning type electron microscope (SEM microscope) of 10,000 magnifications is 5 pieces or lower, and, when a difference between a circumscribed circle and an inscribed circle in the particle boundaries of the particles is measured with a photograph (TEM photograph) obtained by capturing the cross-sections of the porous silica based particles with a transmission electron microscope of 100,000 magnifications, and provided that the value is defined as a surface roughness value, the surface roughness value of the particles is 20 nm, the non-sphericity of the particles is 5% or lower, the particle variation coefficient (CV value) of the particles lies in the range of 5 to 50%, and the specific surface area of the porous silica based particles lies in the range of 97 to 320 m/g. Also provided is a cosmetic obtained by being blended with the porous silica based particles.</p> |
