METHOD FOR SURFACE TREATMENT OF A TITANIUM DIOXIDE PIGMENT.

摘要

The invention relates to a method for the surface treatment of a titanium dioxide with aluminium phosphate and aqueous aluminium oxide, which results in pigments having improved greying stability and at the same time good brightness and opacity. The method is characterised in that, first of all, phosphoric acid is added to a TiO2 suspension having a pH of at least 8, whereupon the pH drops to 3 or below. Subsequently an alkaline aluminium compound is added and the pH increases to at least 5 and thereafter an acid aluminium compound is added, the pH adjusting to 4.5 to 7. The pigment produced according to the method of the invention is excellently suitable for use in decorative paper.