| abstract |
The invention provides a method for treating particulate titanium dioxide. The method comprises: i) providing particulate titanium dioxide, wherein the particulate titanium dioxide is coated with aluminum oxide and / or includes within its crystalline structure aluminum oxide in molar excess of the amount required to compensate for any Nb2056 in said crystal structure; and, subsequently, ii) treating the particulate titanium dioxide with a coating agent that is an alkyl phosphoric acid or an ester thereof, wherein the alkyl phosphoric acid has an alkyl group of 6 to 22 carbon atoms and steam micronizing the dioxide of particulate titanium, where the outlet temperature of the steam leaving the steam micronizer is 150 ° C or more, in order to obtain a micronized particulate titanium dioxide that is provided with a coating agent on its outer surface. The treated particulate titanium dioxide as obtained by the method can be incorporated into a polymer composition so as to increase its fluidity index, improve its dispersibility, increase its hydrophobicity and / or increase its bulk density. |