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 and being provided with a chemically reactive coating comprising a mixture of oxide and oxychloride selected from Al₂O₃ and AIOCI, SiO₂ and SiOCl₂, and ZrO₂ and ZrOCl₂.;These particles are prepared as follows: the surface of the TiO_z particles is activated in a moving bed by means of a thermal treatment with an anhydrous gas at 400°-600°C, and the particles are then made to react in a moving bed at 350°C to 600°C, in the presence of a carrier gas, with an inorganic chloride selected from AlCl₃, SiCl₄ and ZrCl₄.;This new product is useful, for example for preparing TiO₂ pigments coated with organic substances which impart to the pigments an affinity for organic vehicles, for example in paints.