(B) mean particle diameter is below 20nm the resin constituent for the laser marking

摘要

PROBLEM TO BE SOLVED: To obtain the subject composition capable of providing a clear white- based laser marking product excellent in contrast by compounding a carbon black having a specific average particle diameter and DBP oil absorption in a specific amount with a thermoplastic polyester resin. ;SOLUTION: The objective composition comprises (A) a thermoplastic polyester resin (e.g. a polybutylene terephthalate), (B) 0.001-3 wt.%, preferably 0.005-2.5 wt.%, more preferably 0.008-2.0 wt.% carbon black having ≤20 nm, preferably 10-18 nm average particle diameter and 35-130 ml/100 g, preferably 50-115 ml/100 g DBP oil absorption and, optionally, (C) a well-known additive, a filler, a pigment, a dyestuff or the like. A carbon black having a tinctorial power providing a molded product having ≤17.5 L value when compounding 0.15 wt.% component B to the component A and molding a flat board having 2 mm thickness therefrom is preferably used as the component B.;COPYRIGHT: (C)1999,JPO