Abstract: The present invention relates to a silica powder for a cosmetic material, including: amorphous silica particles, in which the silica particles have an average circularity of 0.75 or more, and the silica powder satisfies at least one of the following conditions (1) to (3), (1) a degree of aggregation of 60% or more, (2) an angle of difference between an angle of repose and an angle of collapse of 15 degrees or less, or (3) a degree of dispersion of 50% or less.

Abstract: The present invention relates to a method for producing a spherical silica powder, the method including, firing a spherical and porous silica precursor in a state where particles of the silica precursor are in contact with each other, in which the silica precursor has a sodium concentration of 1 ppm by mass to 300 ppm by mass and assuming the sodium concentration as x (ppm by mass) and a heat treatment temperature as y (° C.), the silica precursor is subjected to the heat treatment at a temperature satisfying ?0.97x+1180<y<?0.97x+1310, or the silica precursor has a pore volume of 0.1 ml/g to 2.0 ml/g and a specific surface area of 200 m2/g to 1000 m2/g.

Abstract: The present invention relates to light-scattering silica particles having a light scattering property, the light-scattering silica particles including: a plurality of hollow portions each having a closed pore structure inside the particle, in which the light-scattering silica particles have a volume-based cumulative 50% particle diameter of 1 ?m to 500 ?m and an average circularity of 0.80 or more, and in use of the light-scattering silica particles, a reflectance A of a water cake containing 20 mg/cm2 of silica per measurement cross-sectional area at an ultraviolet wavelength of 310 nm is 30% or more.

Abstract: The present invention relates to hydrophobic silica particles including silica particles each being impregnated with a higher alcohol having 19 or more carbon atoms, and having a binding degree of the higher alcohol to the silica particles of 70% or more measured by the following measuring method: the measuring method: 1 g of the hydrophobic silica particles is dispersed in 10 mL of tetrahydrofuran, and after maintaining the dispersed state for 5 minutes, a filtered residue is washed with 20 mL of tetrahydrofuran and 20 mL of hexane and dried, and a ratio, represented by Equation (1), of a carbon content of the hydrophobic silica particles after washing to a carbon content of the hydrophobic silica particles before washing is defined as the binding degree, binding degree (%)=carbon content (%) of hydrophobic silica particles after washing/carbon content (%) of hydrophobic silica particles before washing×100 (1).

Abstract: To produce scaly silica particles in which formation of irregular particles is prevented. A process for producing scaly silica particles, which comprises a step of subjecting a silica powder containing silica agglomerates having scaly silica particles agglomerated, to acid treatment at a pH of at most 2, a step of subjecting the silica powder subjected to the acid treatment, to alkali treatment at a pH of at least 8 to deflocculate the silica agglomerates, and a step of wet disintegrating the silica powder subjected to the alkali treatment to obtain scaly silica particles.