| abstract |
A resin composition having laser marking properties with the CO2 laser with radiation at 10600 nm comprises a polyester thermoplastic resin, a sufficient amount of dark pigment for forming a dark background coloration, a mica material for absorbing said laser radiation, and an effective amount of a hydrated metal phosphate containing water of crystallization wherein said metal phosphate decomposes in laser struck areas to release said hydrated water whereby light colored markings in laser struck areas are obtained on said dark background coloration. |