Laser marking method and aqueous laser marking composition

摘要

This invention relates to a laser marking method which comprises heating a base article having on its surface a thin film of a laser marking composition containing a color former and a color developer having a melting point of 200 DEG C. or above, and then applying laser light to the thin film. The method of this invention is capable of no-break marking with vivid color development by application of laser light, without causing discoloration of the ground even under a condition of 120 DEG C. or above.