PROCESS FOR PREPARING TITANIUM DIOXIDE PIGMENT Russian patent published in 1994 - IPC

FIELD: manufacture of dyes. SUBSTANCE: the pH of an aqueous suspension of titanium dioxide is adjusted to 10.0 and heated to 90 C, a sodium silicate solution is added in an amount which is equivalent to 1.2 wt % silicon dioxide deposited, maintained at 90 C and the pH is adjusted to 9.4. After the silicon dioxide coating deposits and solidifies, the pH is adjusted to 3.0, a sodium aluminate solution is added in an amount which is equivalent to 2.8 wt % aluminium oxide and the pH is simultaneously adjusted to 5.0-6.0 and the pH is then adjusted to 7.6 and the pigment is obtained. The pH is adjusted to 10.0 and 7.5 by adding a sodium hydroxide solution and the pH is adjusted to 9.4, 3.0 and 5.0-6.0 by adding a sulfuric acid solution. EFFECT: improved properties of the pigment. 3 cl