| 摘要 |
The present invention describes a novel method for the formation of optically variant pigments by the coating of layers onto a substrate and the fracturing of the coated material into pigment particles after the coating operation and novel pigments produced thereby. Coating techniques such as slot die coating (especially multiple slot die coating), spin coating, meniscus coating, curtain coating, and the like have proven successful. It is preferred that multiple die slots are used to coat multiple layers in a single pass so that manufacturing costs are minimized. The use of these coating techniques, and especially multiple die slot coating, allows for many layers to be coated, with from three to fifty layers being readily possible. This offers a relatively inexpensive way of coating out a wide variety of layers, and especially the pigment materials needed for optically variable pigments, quickly and with high quality. The coating materials may be sols, polymers, composites, reactive mixtures and the like, including combinations of these materials. The properties of the optically variable pigment are determined by the composition, properties and thickness of the coated layers.
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