Studies On The Hydrolysis And Deposition Technique Of The Mica Pearlescent Pigments

Mica pearlescent pigments comprising mica particles coated with thin transparent film consisting of highly refractive metal oxides, When the light rays incident into pigment particle, a portion of light is reflected from the exterior of the film and interfere with the other portion of light transmitted through the film to the extremely smooth surface of mica plate where it is reflected again. Two portion of light suffers a phase change, Viewed by reflected light it exhibit pearly or iridescent optical effects , which depending upon the particle size and the thickness of coatings. The product can be used in plastics, varnishes, enamel, cosmetics, textiles, printings, etc.The laboratory experiments were made on the hydrolysis of TiCl4 solutions and deposition films of Titanium Hydroxides and oxyhydroxides onto the mica powder. And mainly studied the structure transformation of hydrolysis and deposition of the TiCl4 solutions and the dehydrolysis of the Titanium Hydroxides and oxyhydroxides under the sinter processing. Exclude mica powder, the specifically hydrolysis and deposition of some other metal salt such as FeCl3 solutions and the dehydrolysis of the metal Hydroxides and oxyhydroxides under the hydrothermal processing were also studied. Referenced the correlation studies on the other literatures, the common characteristic of hydrolysis of metal salt solution and the dehydrolysis of metal Hydroxides and oxyhydroxides by the hydrothermal method have been Summarized.We have made a lot of factory experiments on the hydrolysis of TiCl4 solutions and deposition the films of titanium hydroxides and oxyhydroxides on the mica powder. The effect mechanisms of temperature, acidity, concentration and velocity on the hydrolysis and deposition are also analysed.In order to evaluate the results of experiments and the quality of products,We also studied the performances such as color, dispersibility, lightfastness, particle sizes of some specifications pigments, and also constitutethe method of measureing these performances.The optical effect of thin film light interference was explained about the illusion of pearlescent pigment color. The interference conditions for thin films were also expoud.