Plate-Like Pigments in Automotive Paints: a Review
- May 14, 2003
In recent years, automotive colors have become an important aspect of car design. Market experience shows that car buyers tend to prefer automotive coatings with high chroma shades based on effect pigments because of their visual impact.1 For creation of clearer, more brilliant and more exciting colors for automotive original equipment manufacturers (OEM) finishes the number of pigment types used has therefore increased considerably in the last decade. An end to this trend is not yet in sight.
In addition to conventional "one-dimensional" organic and inorganic pigments, which interact with light by absorption and/or scattering, more "two- and three-dimensional" plate-like pigments are finding their way onto the market.2 The optical impression of these pigments is based on three kinds of interaction of light. First, if they consist only of small metallic flakes with diameters more than five micrometers the incident light is almost all directly reflected. That means these pigments act as small mirrors, which results in a lightness flop with change of the viewing angle. The "dollar" and "corn flake" types of aluminum pigments belong to this "two-dimensional" pigment group.