Taggent flakes for covert security applications having a selected shape
View Patent ↗A plurality of flakes are provided that can be used in ink or paint wherein the flakes are of a size that requires magnification to see their shape, in the form of polygons, such as squares, triangle or rectangles. A breaking or grinding process is used to break a foil into these shaped flakes and frames or walls are provided within the foil sheet so as to delineate the shapes and these lines provided by frames or walls will facilitate breakage in a preferred manner such that the flakes break into selected shaped polygons. Remnants are typically present along flake edges due to the grinding and breakage process however with magnification, one can see the resultant regular polygonal shape. To clearly see the remnants one requires increased magnification and the remnant itself provides a type of signature. It can be seen as a taggent within a taggent.
1. A plurality of shaped flakes, wherein each flake has a same general polygonal shape, each flake having a thickness greater than or equal to 0.01 μm and less than or equal to 10 μm, and wherein each flake has a remnant in the form of a protruding wall segment on one side of each of the flake wherein the remnant is result of breaking or grinding to form the shaped flakes, and wherein a width of the remnant is less than 20% of a major dimension of the flake so that the general polygonal shape of each flake is distinguishable.
2. A plurality of shaped flakes as defined in claim 1 , wherein one surface of the flake is substantially planar and wherein another opposite surface of the flake is not entirely planar due to the presence of one or more remnants, and wherein the flake is of a size such that the polygonal shape can only be seen with magnification.
3. A plurality of shaped flakes as defined in claim 2 wherein edges of each of the flakes are jagged as a result of a breaking or grinding process.
4. A plurality of shaped flakes as defined in claim 3 comprising a binder.
5. A plurality of shaped flakes wherein the shaped flakes as defined in claim 1 wherein the flakes have indicia thereon.
6. A plurality of shaped flakes as defined in claim 1 wherein a remnant has a width and length in the plane of the flake, and a height.
7. A plurality of shaped flakes as defined in claim 1 wherein the shaped flakes comprise bright flakes.
8. A plurality of shaped flakes of claim 7 wherein the shaped flakes have a grating pattern, the selected shape being visible at a first magnification and the grating pattern not being visible at the first magnification, wherein the grating pattern is visible at a second magnification, the second magnification being greater than the first magnification.
9. A plurality of shaped flakes of claim 1 wherein the shaped flakes include a grating pattern which can only be seen with magnification.
10. A plurality of shaped flakes of claim 2 wherein the flakes have a reflective layer, a spacer layer, and an absorber layer.
11. A plurality of shaped flakes as defined in claim 1 , wherein the shaped flakes include single-layer inorganic dielectric taggent flakes.