Post-treated titanium dioxide, a process for obtaining the same, and a process for preparing a titanium dioxide pigment

摘要

This invention concerns a new product consisting of TiO2 particles having pigmentary granulometric and morphological characteristics. It includes a chemically reactive coating consisting of a mixture of oxides and oxychlorides selected from the group consisting of Al2O3 and AlOCl; SiO2 and SiOCl2; and ZrO2 and ZrOCl2. The particles of reactive TiO2 product are prepared as follows: the surface of the TiO2 particles is activated by thermally treating the particles in a moving bed with an anhydrous gas at 400 DEG -600 DEG C. The particles are then made to react in a moving bed at 350 DEG C. to 600 DEG C., in the presence of a carrier gas, with an inorganic chloride selected from the group consisting of AlCl3, SiCl4 and ZrCl4. This new product is useful, for instance, in TiO2 pigments coated with organic molecules which provide an affinity for the vehicles of paints.