Titanium dioxide powder and cosmetic formulated therewith
AssigneeShiseido Company, Ltd.
InventorHideo Hata
Life of this patent
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Abstract
A titanium dioxide powder has excellent red light-selective transmission function while maintaining hiding power. A cosmetic formulated therewith provides a natural finish and makes skin irregularities (pores) inconspicuous while having good covering properties. A titanium dioxide powder is obtained by firing titanium dioxide having acicular projections on the particle surface at 500-800° C. The titanium dioxide powder for the cosmetic is characterized by an apparent average particle size is 100-500 nm, an average crystallite size measured by X-ray diffraction is 15-30 nm, and a specific surface area is 10-30 m2/g.
Claims4
A method for producing a titanium dioxide powder, comprising:
- a step of calcining rutile titanium dioxide particles having needle projections on the surfaces thereof;
- and
- having an average particle size of 100 nm to 600 nm;
- an average crystallite size of 1 nm to 25 nm;
- and a specific surface area of 40 m2/g to 200 m2/g;
- wherein the obtained titanium dioxide powder has an average particle size of 100 nm to 500 nm;
- an average crystallite size of 15 nm to 30 nm;
- and a specific surface area of 10 m2/g to 30 m2/g, and
- wherein said average particle size is measured using a scale, and said average crystallite size is measured using an X-ray diffraction method.
Dependencies are inferred from the claim text.