Titanium dioxide pigments
Gerhard Pfaff
Abstract
Abstract Titanium dioxide (TiO 2 ) is by far the most important white pigment. The extraordinary scattering behavior of TiO 2 together with the lack of absorption in the visible range and the stability in different application systems is the reason why TiO 2 is the most commonly used pigment. Of the three TiO 2 modifications, only rutile and anatase play a role for pigment uses, whereas brookite has no technical importance. Two main processes are used for the production of TiO 2 pigments, the sulfate process and the chloride process. Many TiO 2 pigments are equipped with an additional surface treatment (aftertreatment) to improve weather resistance and lightfastness of the pigment itself and of the pigmented organic matrix. A second aim of the surface treatment is the improvement of the dispersibility of the pigments in the application system.