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 TiO<Sub>2</Sub> particles having pigmentary granulometric and morphological characteristics and being provided with a chemically reactive coating comprising a mixture of oxide and oxychloride selected from Al<Sub>2</Sub>O<Sub>3</Sub> and AIOCI, SiO<Sub>2</Sub> and SiOCl<Sub>2</Sub>, and ZrO<Sub>2</Sub> and ZrOCl<Sub>2</Sub>.

These particles are prepared as follows: the surface of the TiO<Sub>z</Sub> 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 AlCl<Sub>3</Sub>, SiCl<Sub>4</Sub> and ZrCl<Sub>4</Sub>.

This new product is useful, for example for preparing TiO<Sub>2</Sub> pigments coated with organic substances which impart to the pigments an affinity for organic vehicles, for example in paints.