Security element with thin-layer element
AssigneeGiesecke & Devrient GmbH
InventorsManfred Heim, Ralf Liebler, Markus Krombholz
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Abstract
The invention relates to a security element for security papers, documents of value and the like having a thin-layer element (12) with color shift effect, which has a reflection layer (14), an absorber layer (18) and a spacer layer (16) disposed between reflection layer (14) and absorber layer (18). According to the invention the spacer layer (16) is formed by a printed layer having dispersion particles (20) with monomodal or oligomodal size distribution.
Claims57
A security element for security papers, documents of value and the like, comprising a thin-layer element with color shift effect, said element including a reflection layer, an absorber layer and a spacer layer disposed between reflection layer and absorber layer, and wherein the spacer layer is formed by a printed layer having dispersion particles with monomodal or oligomodal size distribution;
- wherein the printed layer contains a main species of mainly spherical, monodisperse dispersion particles, the diameter of which determines the thickness of the spacer layer;
- and
- wherein the dispersion particles of the main species have a core-shell structure with a high-melting core and an easily film-forming shell.
A method for manufacturing a security element for security papers, documents of value and the like, which contains a thin-layer element with color shift effect that has a reflection layer, an absorber layer and a spacer layer disposed between reflection layer and absorber layer, comprising applying the spacer layer by a printing method with a printing ink having dispersion particles with monomodal or oligomodal size distribution;
- and
- wherein the printed spacer layer is subjected to a heating step, during which at least one constituent of the printing ink melts.
A printing ink with optically variable coloring pigments, comprising interference layer particles, the layer structure of which has a reflection layer, an absorber layer and a spacer layer disposed between reflection layer and absorber layer, wherein the spacer layer is formed by a printing method with dispersion particles having monomodal or oligomodal size distribution, or the layer structure of which comprises a first absorber layer, a first spacer layer, a reflection layer, a second spacer layer and a second absorber layer, wherein the first spacer layer is disposed between the reflection layer and the first absorber layer, the second spacer layer is disposed between the reflection layer and the second absorber layer, and wherein the first and second spacer layer are formed by a first or second printed layer having dispersion particles with monomodal or oligomodal size distribution;
- and
- wherein the dispersion particles of the main species of the first and/or second printed layer have a core-shell structure with a high-melting core and an easily film-forming shell.
A method for producing a printing ink having optically variable coloring pigments, wherein a thin-layer element with color shift effect is applied onto a substrate by applying a reflection layer, an absorber layer, and a spacer layer onto the substrate, wherein the spacer layer is applied with the help of a printing method with dispersion particles having monomodal or oligomodal size distribution, the thin-layer element is removed from the substrate, the removed thin-layer element is ground into a predetermined particle size and the particles are mixed with a binding agent as optically variable coloring pigments;
- and
- wherein after its application the printing ink is subjected to a heating step, during which at least one constituent of the printing ink melts.
Dependencies are inferred from the claim text.