Pigments the change in color of which is dependent on visual angle, process of their preparation, their use for safety purposes and coating compositions containing such pigments as well as detection device

摘要

The invention describes luminescent optically variable pigments (OVP), methods for obtaining such pigments, as well as the use of such pigments as security elements in inks, coatings and articles. The luminescence centers are preferably incorporated into the dielectric material of the OVP's opticalFabry-Perot resonance cavity, allowing for the machine-discrimination of luminescent OVP from simple mixtures of luminescents and non-luminescent OVP.