New Developments for Pearlescent Pigments and Flakes

Coloristic Variations on the Basis of Mica. Mica platelets can be coated with a variety of compounds to produce novel pigments. Solid state reactions and CVD-process enlarge the possibilities for the synthesis of mica pigments. In addition, the calcination of the materials in the presence of inert (e.g. N2, Ar) or reactive gases (e.g. NFI3, H2, hydrocarbons) allows the formation of phases which are not producible by working in air. Table 54 contains a summary of nacreous mica pigments with special coloristic properties. 

Reduction of suitable aqueous metal salts by electroless plating yields metal-coated mica pigments. They are less expensive than noble metal flakes (Au, Ag) and their brilliant metallic appearance is comparable with that of metallic flakes [5.192], [5.193], 

New Developments Based on Non-Micaceous Systems. The class of single crystal lustrous pigments is not limited to the non-absorbing types like bismuth oxychloride and basic lead carbonate. Recent developments are absorbing pigments such as platelet-like graphite, laminar phthalocyanines and flaky iron oxides. These flakes 

Ti02-x/Ti02/Mica Ti02/Mica + H2 (Ti, Si) T 900°C (solid state reaction) grey, blue-grey [5.230] 

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