Combination mica-based pigments

The development of the mica-based pigments started with pearlescent colors (Fig. 76 A, TiOz - mica). It was followed by brilliant, mass-tone-colored combination pigments (i.e., mica, Ti02, and another metal oxide) with one color (interference color same as mass tone) or two colors (interference and mass tone different) that depend on composition and viewing angle (Fig. 76 B). In the 1980s further development was made by coating mica particles with transparent layers of iron(III) oxide (Fig. 76 C) [5.222]. 

Nacreous and interference pigments are used as colorants or part of color formulations for all applications where traditional pigments are used, but where additional color depth, brilliance, iridescence, color shift (flop), and other spectacular effects are desired [5.253]. Mica-based pigments dominate their combination of pearl and interference effects, brilliance, stability, and weather resistance is unsurpassed. Furthermore, they are non-toxic [5.221],... 

The development of the mica-based pigments started with pearl luster colors (Figure 5.18(A), Ti02-mica). This was followed by brilliant, mass-tone-colored, combination pigments (i.e., mica-Ti02, and another metal oxide) with one color (interference... 

Improved color strength and very high luster are produced by the combination of precise thickness silica flake substrate materials, selected for their interference chro-maticity, and by deposition of titania or iron oxide coating layers of the precise thickness required to generate the same interference color. These pearl luster pigments show stronger chromaticity L a b -values than can be produced with mica-based designs. 

On the other hand, new pigments based on transparent silica flakes show extremely strong optical effects, which are different to mica pigments [5.244]. Angle dependent colors and other effects, achieved by the combination of these Si02-flakes with... 

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