Ink composition for marking and identification of objects

摘要

An ink for marking and authenticating articles contains: (a) a dye or non-photochromic pigment; (b) a dye or photochromic pigment; and (c) a solvent. The dye or photochromic pigment changes the absorption spectrum under the effect of a 1st light source emitting in the Uv, in such a way that when it is illuminated later and solely by a 2nd light emitting in the visible region, it gives a colour different from that given when it is exposed to the 2nd light source without previous exposure to the 1st light source. The colour is also different from that given by the dye or the non-photochromic pigment when this is exposed to the 2nd light source.