Study On Preparation Of Mica Pearlescent Pigments In Chemical Liquid Deposition Method And Formation Mechanism

Mica pearlescent pigments were prepared by one or more layers of high refractive index oxides depositing on the surface of mica flakes which had a pearl luster effect under the irradiation of light. With its excellent chemical stability, color diversity, high security and other advantages in life, mica pearlescent pigments were widely used. Mica pearlescent pigments can be divided into the one-layer structure and multi-layer structure. Among them, one-layer structure of mica-titanium pearlescent pigments and mica-iron oxide pearlescent pigments were the most widely used. The study on how to prepare rutile mica-titanium pearlescent pigments quickly discussed most, while pure anatase mica-titanium pearlescent pigments and mica-iron oxide pearlescent pigments got much less attention.In this paper, mica-titanium pearlescent pigments were synthesized by the chemical liquid phase deposition method which was used fluorophlogopite as the substrate coating one lay of metal oxide on it. First of all, we used different titanium sources and crystal accelerators seperately to prepare the pure rutile and pure anatase mica-titanium pearlescent pigments. Then we prepared the mica-iron oxide pearlescent pigments.The influence of preparation process factors like the pre-treatment of mica powders, solution concentration, pH value, reaction temperature, dropping rate, stirring rate, the ratio of solid to liquid, calcination temperature and calcination time on the mica pearlescent pigments were studied by XRD, SEM, EDS, TG-DTA tests and pearlescent degree analysis. At the same time, the phase transformation process and formation mechanism of mica pearlescent pigments were discussed by these tests including XPS.