From the aspect of actual use of electro-conductive powders in polymers, the color and dispersibility of ATO-coated TiO2 powders are important characteristics in addition to electro-conductivity. To investigate how to best meet these requirements, the roles of various factors, such as the Sb/SnO2 weight ratio, the double coating ratio during the hydrolysis step, adjustment of pH, duration of PC dispersion, and degrees of pulverization were experimentally examined. The color and electro-conductivity of ATO-coated powders can be controlled to some extent by selecting a suitable Sb/SnO2 weight ratio as well as by adjusting the pH. To obtain powders of high whiteness, it is desirable to increase the Na2O content in ATO-coated powders. The dispersibility of electro-conductive powders in polymer and the surface resistivity of the resulting composite can be easily adjusted by using sodium hydroxide for the hydrolysis of an acidified mixture of metal chlorides in a solution of ATO composition. Hydrolysis at low pH benefits low surface resistivity, while hydrolysis at a high pH value results in superior dispersibility.
