| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a plastic multilayered sheet which enables laser marking not damaging appearance, good in contrast and excellent in surface smoothness and has excellent heat resistance, and a laser marking method using it. <P>SOLUTION: The multilayered sheet for laser marking composed of a first surface layer, an inner layer and a second surface layer is formed of first and second transparent surface layers composed of a thermoplastic resin composition (A) containing 0.0001-5 pts.wt. of mica and/or carbon black with respect to 100 pts.wt. of a transparent thermoplastic resin and the inner layer comprising a thermoplastic resin composition (B) containing 0.001-3 pts.wt. of an energy absorber for absorbing a laser beam with respect to 100 pts.wt. of the thermoplastic resin. The thickness constitution ratio of the sheet of first surface layer/inner layer/second surface layer is 1:4:1-1:10:1. The multilayered sheet for laser marking is formed by the melt coextrusion of the first surface layer/inner layer/second surface layer. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
