Mehrschichtiger Aufzeichnungsträger und Verfahren zum Beschriften eines mehrschichtigen Aufzeichnungsträgers

摘要

For multicolour marking of identity cards and the like, the multilayer identity card is provided with an outer coloured layer in a first colour and an inner coloured layer in a second colour. While the outer coloured layer absorbs virtually none of the laser light used for marking, the second, inner coloured layer absorbs the laser light. This causes the material in the second coloured layer to be thermally degraded, i.e. evaporated, sublimed or subjected to a chemical or physical reaction, during the marking operation, with the consequence that formation of pressure causes the first layer to be broken up into particles, causing the second coloured layer to become visible. The second coloured layer may also be replaced by a transparent coat of varnish having appropriate properties in order to expose, for example, a multicolour security printed image under this transparent coat of varnish. ……