Patent ID: 7217745

Claim:
A laser-markable transparent or translucent plastic composition, which comprises a transparent or translucent plastic and a laser absorbing pigment mixture, said mixture consisting of a pearlescent pigment in combination with a laser-sensitive pigment, wherein the pearlescent pigment comprises a phyllosilicate substrate having one or more layers of metal oxide thereon, wherein the laser-sensitive pigment is composed of mica coated with one or more metal oxides, the nature and thickness of the coating(s) on the mica being such that no pearlescent effect occurs from the laser-sensitive pigment, and wherein the laser-markable plastic composition comprises from 0.1 to 2% by weight of the pearlescent pigment and from 0.1 to 1.0% by weight of the laser-sensitive pigment, based on the weight of the plastic.