TITANIUM DIOXIDE PIGMENT AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To produce a titanium dioxide pigment improved in hydrophobicity and dispersibility by adding an organosilane compound to an aqueous slurry of an acidic titanium dioxide and hydrolyzing the organosilane compound to fix a hydrolyzate of the compound on the surfaces of the titanium dioxide particles. SOLUTION: An acid is added to an aqueous slurry containing 50-800 g/l, desirably 100-500 g/l of titanium dioxide having a mean particle diameter of 0.1-0.4μm to adjust its pH to 0.5-6. An organosilane compound of the formula: Rx -Si(OR')4-n (R is a 10C or lower hydrocarbon group containing at least one alkyl, vinyl or methacrylic group, R' is methyl or ethyl; and n is 1-3) is added to the above obtained slurry and hydrolyzed to fix a hydrolyzate or the compound on the surfaces of the titanium dioxide particles and to obtain a titanium dioxide pigment having a water content of 1,700 ppm or below and a dispersibility of 20 kg/cm<2> or below.