| 摘要 |
<p>Nacreous pigments consist of mica platelets, pref. 5-200 microns in dia., coated with a layer of TiO2 and a thin film of MnO2. The pigments are produced by suspending the mica platelets in water at pH 0.5-5, heating the soln. to 50-100≰C, adding a soluble Ti salt and an opt. other metal oxide, increasing the pH to above 3 and adding Mn at 50-100≰C while keeping the pH constant to MnO2. The coated platelets are washed, dried and calcined to obtain the platelets with a good light stability.</p> |
