Study On Surface Modification Of Titanium Dioxide Pigment

Dispersing method,particle size,pH and dispersant are critical parameters which affect the dispersibility of TiO2 related to coating effect,It has been investigated that dispersion is favored by sand milling, classification,pH cotrolling and suitable dispersant.By means of liquid phase deposition(LPD)method,the experiment for inorganic coatings on rutile TiO2 particles were made under different conditions,hence-after composite particles with a surface layer of dense silica and alumina coating on rutile TiO₂ were obtained and then the surface of rutile TiO2 was modified. The effects on coating results were studied under different technological conditions. The technological parameters were decided according to the change of acid solubility, dispersion and whiteness of TiO2 particles after coating. The mechanism of TiO2 particles coating was studied. It was founded that, the optimal coating method is silica and alumina coating, dense silica coating, Si/Al ratio 1:4. The weatherability and optic capability of the samples is the best under this technological condition.By means of orthogonal experiments, the optimal surface modifying agent was selected. The process conditions: concentration, the amount, time, temperature were discussed, and the optimal organic modifying agent and method were obtained.