Preparation method of special titanium dioxide pigment for electrophoretic paint

The invention provides a preparation method of a special titanium dioxide pigment for an electrophoretic paint. The preparation method comprises the steps: preparing a titanium dioxide rutile primary product which is prepared by a chlorination method into slurry, adjusting the pH value, adding a silicate dispersant, and carrying out grinding treatment after dispersion; heating the ground slurry, adding a water-soluble meta-aluminate solution, adjusting the pH value, aging, and covering surfaces of the titanium dioxide particles with a layer of hydrated alumina; adding the water-soluble meta-aluminate solution, adjusting the pH value, aging, and covering the surface of the hydrated alumina with a second layer of boehmite or imitation boehmite alumina; adjusting the pH value of the terminal point and aging; and washing with water, filtering and drying, and carrying out steam-powder treatment to obtain the special titanium dioxide pigment for the electrophoretic paint. The titanium dioxide pigment prepared by the method is excellent in light resistance, covering power and tinting strength; the special titanium dioxide pigment product shows a blue undertone, and is high in electrical resistivity and good in dispersing performance; therefore, the titanium dioxide pigment meets the requirements in the high-grade electrophoretic paint field.