MULTI-COLOR COLORING LASER MARKING-USE CHROMATIC COLOR COLORANT, MULTI-COLOR COLORING LASER MARKING-USE COMPOSITION AND MOLDING CONTAINING IT, MULTI-COLOR MARKING-CARRYING MOLDING AND LASER MARKING METHOD

摘要

The objective of the present invention is to provide a chromatic coloring agent for multicolor laser marking, capable of forming clear markings having two or more different color tones when two or more laser beams having different energy levels are irradiated onto different places of a molded article, a composition for multicolor laser marking, for example, capable of forming a chromatic marking derived from the chromatic coloring agent and a white marking on the surface of a molded article whose base color is black or dark-color based color, a laser marking method, a multicolor-marked molded article and the like. The present chromatic coloring agent has an exothermic peak in the range of 360°C or higher and 590°C or lower, as measured by differential thermal analysis. The present laser marking composition comprises a chromatic coloring agent, a black substance (carbon black or the like) which is itself depleted or discolored by receiving a laser beam, and a polymer, and the contents of the chromatic coloring agent and the black substance are respectively 0.001 to 3 parts by mass and 0.01 to 2 parts by mass with respect to 100 parts by mass of the polymer.