摘要 |
<p>Titanium dioxide pigment prepared by the high pressure (e.g., 10-200 PSIG) oxidation of TiCl4 vapor is improved with respect to carbon black undertone, specific surface area, and gloss properties by the addition of a nucleant consisting essentially of a cesium substance which is present in the amount of about 8-2,000 parts per million, based on the weight of the TiO2. The foregoing process is also used wherein the residence time of the reactants in the mixing zone of the reactor is about 1-16 milliseconds.</p> |