Gerhard Wilker is part of the Marketing & Sales Marketing Coating Business, Technical Marketing Automotive Coating | Clariant (Deutschland) GmbH, Frankfurt, Germany<p>
Several pigment combinations are suitable for the formulation of green color shades. For economic reasons, “complementary pigment combinations” are often used. These are green shades that are generated by mixing yellow and blue pigments. However, these mixtures may bear significant risk in terms of weather fastness, especially when the fastness properties and the pigment concentrations are not balanced, or when the formulation contains a large portion of titanium dioxide. In combination with the effect of sunlight and weathering, all of this can lead to undesirable and unacceptable color changes in the coating.
Clariant undertook extensive tests to determine which pigment mixtures are suitable for outdoor use. Based on these tests, it could be demonstrated that different pigment mixtures generate color variations in green coatings, and suitable alternatives were identified. The results presented in this article for the color “green” can be generally transferred to other color shades.