POWDER MIXTURE CONSISTING OF TITANIUM DIOXIDE, ZINC OXIDE AND ZINC/TITANIUM MIXED OXIDE

摘要

A powder mixture consisting of zinc/titanium mixed oxide particles, titanium dioxide particles and zinc oxide particles, wherein the zinc/titanium mixed oxide particles have a composition according to the formula (ZnO)1-x(TiO2)x, where 0.01 < x < 0.99, and are obtained from a thermal process and the powder mixture exhibits remission which, in the UV range from 320 to 400 nm, is lower than that of titanium dioxide and, in the UV range below 320 nm, is lower than that of zinc oxide. The powder mixture may be produced by introducing into a flame, as is used for the production of pyrogenic metal oxides by means of flame hydrolysis, an aerosol of a zinc compound, homogeneously mixing said aerosol with the flame hydrolysis gas mixture, allowing the aerosol/gas mixture to react in a flame, separating the solid reaction products from the stream of gas and then performing thermal treatment. The powder mixture may also be produced by dispersing titanium dioxide powder in the presence of a solution of a zinc compound, wherein the ratio of titanium dioxide and zinc salt corresponds to the subsequently desired ratio of titanium dioxide and zinc oxide in the final product, then removing the solvent by evaporation and thermally treating the residue. The powder mixture may be used in sunscreen preparations.