| abstract |
The invention relates to titanium dioxide pigment particles which have improved photo stability, their surface being coated with a dense SiO2 skin that is doped with at least one doping element. The SiO2 skin is characterized in that the doping with the at least one doping element reduces the energy level densities in the valence band and/or in the conduction band in the vicinity of the band gap or that additional energy levels in the band gap are produced. The doped dense SiO2 skin is applied using known wet-chemical methods or is applied in the gas phase to the surface of the titanium dioxide particles. Particularly suitable doping elements are Sn, Sb, In, Ge, Y, Nb, F, Mn, Cu, Mo, Cd, Ce, W and Bi. The following known doping elements AI, B, Ge, Mg, Nb, P, Zr for the gas phase method and Ag, AI, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Mg, Mn, Ni, Nb, Sn, Sr, Ti, Zn, Zr for the wet-chemical method are excluded from the invention. |