| 摘要 |
PURPOSE:To readily obtain an excellently pearlescent pigment having rutile titanium dioxide film of high weatherability, by the treatment, using as a flux a metal (belonging to the II-group in the periodic table) halide, of a mica having hydrated or anatase-type titanium dioxide film followed by calcination. CONSTITUTION:A flaky particulate mica coated with hydrated or anatase-type titanium dioxide film is treated, for example, at 50 deg.Cfor 1hr., with an aqueous solution of metal (belonging to the II-group in the periodic table) halide (e.g., MgCl2, ZnCl2, CaCl2, BaCl2), a flux for titanium dioxide, to attach said halide to the particulate mica surface followed by calcination at 800-1,000 deg.C, then gradual cooling. The amount of said aqueous solution to be used is pref. 0.1-1.0 time that of the titanium dioxide. Subsequently, said metal helide is washed off followed by drying, thus obtaining the objective pigment coated with titanium dioxide film mainly of rutile type.
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