Radiation curable embossed ink security devices for security documents

Abstract

A method of manufacturing a security document comprising the steps of providing a transparent plastics substrate, applying a radiation curable ink directly to at least side of the substrate and simultaneously embossing and curing with radiation different regions in the same area of the ink on one side of the substrate with at least two different embossed relief structures, each forming a different type of diffractive security element integrated within the same area to form a composite security device.

What is claimed is: 
     
         1 . A security document comprising a transparent plastics substrate and a continuous layer of embossed radiation cured ink applied to a surface of the substrate, wherein the embossed ink includes at least two different embossed relief structures embossed into said layer of the radiation cured ink on one side of the substrate, each embossed relief structure forming a different type of diffractive security element integrated into a different region of said layer of radiation curable ink to form a composite security device, wherein said security element are located within 0.3 mm of one another. 
     
     
         2 . The security document according to  claim 1 , wherein at least one of the security elements is a light transmissive security element. 
     
     
         3 . The security document according to  claim 2 , wherein the, or each, light transmissive security element is formed from an embossed transparent ink. 
     
     
         4 . The security document according to  claim 1 , wherein at least one security element is configured for verifying another security feature provided on the security document. 
     
     
         5 . The security document according to  claim 1 , wherein one security element is configured for verifying another security feature provided on the security document, and the other security element is an inspectable security element. 
     
     
         6 . The security document according to  claim 5 , wherein the security element configured for verifying another security feature provided on the security document includes a diffractive filter or holographic filter. 
     
     
         7 . The security document according to  claim 1 , wherein said security elements are located within 0.1 mm of one another. 
     
     
         8 . The security document according to  claim 1 , wherein the composite security device is located in a window area of the substrate. 
     
     
         9 . The security document according to  claim 1 , wherein the composite security device is located in a half-window area of the substrate. 
     
     
         10 . The security document according to  claim 1 , wherein the security document is a banknote. 
     
     
         11 . A method of manufacturing a security document comprising the steps of:
 providing a transparent plastics substrate;   applying a radiation curable ink directly to at least side of the substrate; and   simultaneously embossing and curing with radiation different regions in the same area of the ink on one side of the substrate with at least two different embossed relief structures each forming a different type of diffractive security element integrated within the same area to form a composite security device.   
     
     
         12 . The method according to  claim 11 , wherein the radiation curable ink is a transparent ink or lacquer formed from a clear resin material. 
     
     
         13 . The method according to  claim 12 , including the step of applying a metallic ink composition onto the transparent ink or lacquer. 
     
     
         14 . The method according to  claim 11 , wherein the radiation curable ink is applied in a gravure printing process. 
     
     
         15 . The method according to  claim 11 , wherein the radiation curable ink includes a metallic ink composition applied in a layer which is sufficiently think to allow the transmission of light. 
     
     
         16 . The method according to  claim 11 , wherein the composite security device is located in a window region of the substrate. 
     
     
         17 . The method according to  claim 11 , wherein the composite security device is located in a half-window region of the substrate. 
     
     
         18 . The method according to  claim 11 , wherein the security document is a banknote.