Substrates

Abstract

This invention relates to improvements in substrates and in particular to new substrates having magnetic and visual security features, which provide security against imitation. A security substrate comprising a transparent carrier layer bearing indicia formed from a plurality of opaque and non-opaque regions and a transparent magnetic layer supported by the carrier layer containing a distribution of particles of a hard magnetic material of a size and distributed in a concentration at which the magnetic layer remains transparent.

1 . A security substrate comprising a transparent polymer carrier layer bearing indicia formed from a plurality of opaque and non opaque regions and a clear transparent magnetic layer supported by the carrier layer containing a distribution of particles of a hard magnetic material of a size and distributed in a concentration at which the magnetic layer remains transparent, characterized in that the magnetic layer contains between 1 and 50% by weight of magnetic material.  
   
   
       2 . A security substrate as claimed in  claim 1  in which the transparent magnetic layer comprises a varnish in which are suspended the magnetic particles.  
   
   
       3 . A security substrate as claimed in  claim 1  in which the transparent magnetic layer lies between the carrier layer and the indicia.  
   
   
       4 . A security substrate as claimed in  claim 1  in which the indicia are formed on the carrier layer and the transparent magnetic layer covers the indicia.  
   
   
       5 . A security substrate comprising a clear transparent polymer carrier layer, bearing indicia formed from a plurality of opaque and non opaque regions, which carrier layer contains a distribution of particles of a hard magnetic material of a size and distributed in a concentration at which the carrier layer remains clear and transparent.  
   
   
       6 . A security substrate as claimed in  claim 1  or  claim 5  further comprising an additional layer of a transparent polymer laminated to the magnetic layer and/or indicia.  
   
   
       7 . A security substrate as claimed in  claim 1  or  claim 5  further comprising a layer of adhesive applied to at least one side of the substrate.  
   
   
       8 . A security substrate as claimed in  claim 1  or  claim 5  in which a layer of adhesive overlies the indicia.  
   
   
       9 . A security substrate as claimed in  claim 1  or  claim 5  further comprising a layer of high refractive index material.  
   
   
       10 . A security substrate as claimed in  claim 1  or  claim 5  in which the indicia are provided by partially demetallising a metal layer, with remaining metal forming the opaque regions and the demetallised regions forming the non-opaque regions.  
   
   
       11 . A security substrate as claimed in  claim 1  or  claim 5  in which the indicia are printed.  
   
   
       12 . A security substrate as claimed in  claim 1  or  claim 5  further including additional printed regions formed from one or more inks having iridescent, luminescent, optically variable, liquid crystal, thermochromic and/or photochromic properties.  
   
   
       13 . A security substrate as claimed in  claim 1  or  claim 5  comprising indicia provided by demetallised and metallised regions and printed indicia.  
   
   
       14 . A security substrate as claimed in  claim 13  in which the printed indicia overlie at least some of the metallic regions.  
   
   
       15 . A security substrate as claimed in  claim 13  in which the printed indicia lie within the demetallised regions.  
   
   
       16 . A security substrate as claimed in  claim 1  or  claim 5  further comprising an optically variable device.  
   
   
       17 . A security substrate as claimed in  claim 16  in which the optically variable device is formed by embossing a layer of embossing lacquer.  
   
   
       18 . A security substrate as claimed in  claim 16  in which the embossing lacquer lies between the magnetic layer and the indicia.  
   
   
       19 . A security substrate as claimed in  claim 17  in which the embossing layer lies between the transparent magnetic layer and a layer of high refractive index.  
   
   
       20 . A security substrate as claimed in  claim 17  wherein the embossing layer overlies the indicia.  
   
   
       21 . An elongate security element made by the step of slitting the substrate as claimed in  claim 1  or  claim 5  in register with the indicia.  
   
   
       22 . A security document comprising a paper or polymer substrate incorporating a security thread as claimed in  claim 21.