| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polyester resin compsn. which, when used in marking by means of a laser beam, can yield a marking letter having excellent contrast by incorporating a graphite intercalation compd. into a thermoplastic polyester resin. SOLUTION: A thermoplastic polyester resin (A) (e.g. polybutylene terephthalate) in an amt. of 100 pts.wt., 0.01 to 5 pts.wt. graphite intercalation compd. (B), 3 to 50 pts.wt. bromine-based flame retardant (C) (e.g. brominated epoxy resin), and 1 to 30 pts.wt. antimony-based flame retardant (D) (e.g. Sb2 O3 ) are mixed together to prepare this polyester resin compsn. The graphite intercalation compd. should be a compd. having a crystal structure with the lattice-to- lattice spacing of carbon being not less than 7Åand is prepd. by intercalating an intercalating substance, such as an acid, an alkali metal, a halogen or the like into a purified graphite by electrolytic treatment or the like. Exposure of the surface of a molded article obtd. from the resultant polyester resin compsn. to a laser beam can offer a marking letter having a high contrast in a short time. |
