SECURITY DOCUMENT INCLUDING A MAGNETIC WATERMARK AND METHOD OF PRODUCTION THEREOF

摘要

One aspect of the present invention provides a security document (1) comprising: a sheet-like substrate of plastics material (6) having first and second opposing surfaces (7, 8), and a first layer of polymer material (12, 13) coating at least said first opposing surface, wherein said first layer (12, 13) contains magnetic particles for forming a magnetic watermark (14) in a first location on said security document. Another aspect of the present invention provides a method of producing a security document (1), comprising the steps of: (a) forming a sheet-like substrate of plastics material (6) having first and second opposing surfaces (7, 8), (b) coating a first layer of polymer material (12, 13) containing magnetic particles on said first opposing surface, (c) melting at least a portion of said first layer (12) such that the magnetic particles can orient under the influence of a magnetic field, (d) applying said magnetic field so as to form a magnetic watermark (14), and (e) allowing said first layer portion (14) to cool so as to fix the orientation of said magnetic particles.