Abstract:
In a plurality of asymmetric color-shifting flakes, each flake has an asymmetric magnetic core with a magnetic layer visible on the first side of the core and a non-magnetic reflector layer on the magnetic layer, visible on the second side of the core. The flake has a spacer layer and an absorber layer on the first side of the core, and also a spacer layer and an absorber layer on the second side of the core, for providing color shifting effects. The material of the magnetic layer is different from the material of the reflector layer, and may be more stable when exposed to a chemical. When a coating with the asymmetric color-shifting flakes is exposed to the chemical, it may have better optical performance than a coating with symmetric color-shifting flakes.
Abstract:
A security image and method of forming said image is disclosed wherein a substrate having an image or indicia thereon is coated with a dilute solution of pigment flakes in an ink or paint. The flakes are subsequently aligned in a magnetic field and are fixed after the field is applied. Most or all of the flakes in a region are aligned so as to be partially upstanding wherein their faces are essentially parallel. Coating the image with flakes yields a latent image which can be clearly seen at a small range of predetermined angles.
Abstract:
In a printed article, pigment flakes are magnetically aligned so as to form curved patterns in a plurality of cross-sections normal a continuous imaginary line, wherein radii of the curved patterns increase along the imaginary line from the first point to the second point. When light is incident upon the aligned pigment flakes from a light source, light reflected from the aligned pattern forms a bright image which appears to gradually change its shape and move from one side of the continuous imaginary line to another side of the continuous imaginary line when the substrate is tilted with respect to the light source.