To obtain fan-shaped or discoidal titanium dioxide having a high UV light- screening effect (especially UV-A screening effect), high dispersibility and high transparency and useful for sunscreen cosmetics, UV light-preventing coatings, UV light- preventing agents by aggregating and/or binding acircular titanium dioxide particles and specifying the side, thickness and specific surface area of the titanium dioxide.
This fan-shaped titanium dioxide has a side of 0.05-0.2μm, especially 0.08-0.15μm, a thickness of 0.02-0.1μm, especially 0.03-0.06μm, and a specific surface area of 90-180m2/g, especially 95-130m2/g. The fan-shaped titanium dioxide is produced by neutralizing a titanyl sulfate solution or titanium tetrachloride solution with an alkali, adding hydrochloric acid to the obtained orthotitanic acid, and subsequently subjecting the obtained solution having a TiO2 concentration of 80-140g/L and a hydrochloric acid concentration of 90-150g/L to a synthetic reaction at a temperature of 25-60°C. The obtained fan-shaped titanium dioxide particles and the discoidal titanium dioxide particles are coated with the water-containing oxide of aluminum, silicon, etc., further coated with water-containing iron oxide and subsequently calcined to obtain the material useful for sunscreen cosmetic.
YAMAZAKI TAKANORI
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