Irreversible application of an invisible marking to polymer mouldings

摘要

The invention relates to a process for the irreversible application of a marking invisible to the naked eye to a polymer moulding with the aid of laser radiation. The invention also relates to polymer compositions suitable for this purpose and to invisibly markable and marked mouldings that are entirely or partly made of the polymer composition. Invisible markings are for example useful for security purposes, for example to prevent unauthorized copying. The moulding is entirely or partly made of a polymer composition containing a polymer and a compound (I), which compound through laser radiation can be irreversibly converted into a compound (II) that yields a visible contrast in the polymer composition only when irradiated with electromagnetic radiation at a wavelength outside the visible range of 400 to 700 nm.