Effect pigments—past, present and future

Driven by trends in fashion, automotive and other consumer markets, pigments that generate special effects like angle-dependent color or decorative texture have a growing economic significance and can be found in various industrial products and end-user applications [G. Pfaff, K.D. Franz, R. Emmert, K. Nitta, R. Besold, Ullmann's Encyclopedia of Industrial Chemistry: Pigments, Inorganic, Section 4.3, sixth ed., VCH Verlagsgesellschaft, Weinheim, Germany, 1998 (electronic release)]. In decorative uses, special effect pigments provide three major advantages: (a) they can create the illusion of optical depth, which is for example be observed when applying pearlescent pigments in car paints; (b) they can generate subtle to startling angle-dependent eye-catching color effects, which can for example be used in car paints or decorative printing; (c) the have the ability to imitate the effect of natural pearls in buttons, plastic bottles, and many other decorative objects. Pearlescent pigments have been reviewed in a number of publications [L.M. Greenstein, in: P.R. Lewis (Ed.), Pigment Handbook, vol. I, second ed., John Wiley & Sons, New York, 1998, p. 829; R. Maisch, M. Weigand, Pearl Luster Pigments, Verlag Moderne Industrie, Landsberg/Lech, Germany, 1991; R. Glausch, M. Kieser, R. Maisch, G. Pfaff, J. Weitzel, in: U. Zorll (Ed.), Special Effect Pigments, Vincentz Verlag, Hannover, Germany, 1998; G. Pfaff, P. Reynders, Chem. Rev. 99 (1999) 1963; G. Pfaff, Chem. unserer Zeit 31 (1997) 6]. This paper provides additional information on the latest developments related to effect pigments and their production technology, the orientation behavior of effect pigment particles and the analytical methods used for the investigation of inorganic layers in effect pigments.