Chemically Modified Mica
Institute of Inorganic Chemistry, Academy of Sciences of the Czech Republic, Rez near Prague
The surface-colored mica pigment is mica chemically modified by controlled homogeneous hydrolysis of sulfates mainly of transition metals, such as Ti, Cr, Fe, Co, Ni, Zn, Al, and Cu, in the presence of urea, with possible thermal after-treatment. Properties of the resulting pigment depend on granularity of mica, its degree of delamination, and on the thickness of the deposited metal oxide used after delamination. Flakes of colored mica were coated with metal oxide layers by homogeneous precipitation of metal sulfates with urea in aqueous medium at 95-98 °C.
Full text (PDF)