Patent ID: 8845803
Filing Date: 2014-09-30
Classification: B82Y,C01P,C09C,C09D,D21H

Abstract:
1. A method for the surface treatment of inorganic pigment particles, comprising the steps of: a) providing an aqueous suspension of untreated titanium dioxide particles with a pH value of at least about 8; b) subsequently adding phosphoric acid and an alkaline aluminum compound; c) subsequently, adding an acid aluminum compound to obtain a pH value of from about 4.5 to about 7; d) preparing an aqueous solution having a pH of from about 4.5 to about 7 from at least one alkaline aluminum compound and an acid component, or from at least one acid aluminum compound and an alkaline component; e) precipitating a precipitation product comprising one or more inorganic aluminum compounds from the aqueous solution, where the precipitation product consists of agglomerates of fine primary particles and/or of single crystals, f) Addition of the precipitation product to the aqueous titanium dioxide suspension.