What is necessary to know about pigments and coatings to compose a "sparkling" visual texture?

To achieve a color or color travel in an effect coating a high area coverage of the surface by the effect pigment in charge is required. To achieve a pronounced sparkle in effect coatings it requires a low area concentration of highly reflecting effect pigments. In practice different effect pigments are compared for both purposes by producing samples having the same mass concentrations, - irrespective to the pigment density and the geometric dimension of the plate-shaped pigments. This paper gives the results of color and sparkle data on samples prepared either with the same number concentration or the same area coverage of pigments. In this way the results of integral coloristic and texture assessments are compared with those of the individual pigments reflectance obtained by micro-spectrometric analysis. For the study typical effect pigments showing a broad range in size, thickness, aspect ratio and reflectivity are chosen. The mean nearest neighbor distances cover also the situation in which the sparkle points detected by the naked eye are produced solely by single pigment flake reflections. These data are suitable to explain the different behavior of transparent and opaque effect pigments in white three-coat-systems.
Duration: 24:25
Speaker: Kirsten Fritsche
Company: Merck KGaA
Conference: European Coatings CONGRESS
Session: Pigments
Location: Nürnberg
Date: 20.04.2015