Surface-modified zinc oxide particles, liquid dispersion, and cosmetic

Surface-modified zinc oxide particles,

• wherein the surface-modified zinc oxide particles have a silane coupling agent having an alkoxy group on surfaces thereof, and a particle diameter d50 thereof is 4 μm or less,
• wherein the particle diameter d50 reflects a dispersion state of the surface-modified zinc oxide particles, including a degree of agglomeration thereof, in a measurement solution,
• wherein the particle diameter d50 represents a particle diameter at which a cumulative volume percentage of a particle size distribution of the surface-modified zinc oxide particles in the measurement solution is 50%,
• wherein the particle diameter d50 is obtained when the surface-modified zinc oxide particles are measured with a laser diffraction/scattering type particle size distribution-measuring instrument by following a measurement method
• wherein the measurement method includes the following:
• 10 g of the surface-modified zinc oxide particles, 88 g of cyclopentasiloxane, and 2 g of polyglyceryl-3 polydimethylsiloxyethyl dimethicone are mixed to obtain a liquid mixture,
• a dispersion treatment is performed on the liquid mixture at 9,500 rpm for 5 minutes using a homogenizer to obtain a liquid dispersion,
• the liquid dispersion is diluted with cyclopentasiloxane so that a content of the surface-modified zinc oxide particles in the liquid dispersion is 0.01% by mass to produce the measurement solution, and
• the particle diameter d50 is measured with the laser diffraction/scattering type particle size distribution-measuring instrument using the measurement solution.