Patent ID: 9205033
Filing Date: 2015-12-08
Classification: A61K,A61Q,B82Y,C01P,C09C

Abstract:
1. Composite spherical polymer particles used as a raw material for cosmetics comprising: a nanoparticulate pigment having an average primary particle size in a range from 0.1 to 0.005 μm; a (meth)acrylic resin that is a polymer obtained from a combination of monomer (A) and monomer (B) or the monomer (B) alone, a dispersant having a polyurethane structure or a poly(meth)acrylic molecular structure, a polystyrene equivalent weight average molecular weight from 3,000 to 30,000, functional groups capable of adsorbing on particle surfaces of the nanoparticulate pigment, and functional groups having compatibility with the monomers as a dispersion medium, wherein the composite spherical polymer particles are formed of the nanoparticulate pigment incorporated in a uniformly dispersed state in the (meth)acrylic resin in the presence of the dispersant, a content of the nanoparticulate pigment ranges from 5 to 70 wt % relative to the composite spherical polymer particles, the composite spherical polymer particles have an average particle size from 1 to 20 μm, and the composite spherical polymer particles have light transmittance in a range from about 50 to about 95% measured at a wavelength range from 390 to 750 nm when the composite spherical polymer particles include nanoparticulate titanium oxide or nanoparticulate zinc oxide as the nanoparticulate pigment in an amount in a range from 20 to 40 mass %.