Abstract
A colored pearly luster pigment without any coloring materials was developed by electroless nickel plating onto titanium dioxide coated mica (TiO2-mica) which showed interference color. Various appearance colors could be obtained by controlling the thickness of TiO2-mica plate. Their appearance colors and blightness were almost equal to the interference color of TiO2-mica of a raw material. SEM analysis showed that TiO2-mica were coated with ultra fine nickel particles (particle size < 5nm). Furthermore, XPS analysis showed that the oxidation states of the nickel particle on the TiO2-mica could be controlled with the drying temperature or through the calcinating process. Ni(OH)2 and Ni were found in the sample treated at 25°C for 24 hr, and Ni2O2 and Ni at 150°C for 24hr. Nickel particle composed of Ni2O2 and Ni was stable at further calcination, because of the passive valence state Ni2O2.
