Thermoplastic polyester resin composition

#The invention relates to a thermoplastic polyester resin composition which is excellent in mechanical characteristics in addition to flame resistance even if the resin composition does not include any halogen series flame retardant, and to a molded article using the same.

#The thermoplastic polyester resin is widely used for electrical and electronics equipment components in addition to automobile components from the viewpoint of the excellent characteristics. Heretofore, various recipes for such a resin have been developed so as to satisfy desired characteristics, and thereby achievement of high functionality and high performance has been made.

#However, in recent years, characteristics to be desired are becoming higher, and therefore, it is becoming difficult to manage to use conventional recipes. For example, in recent years, electronic components such as connector are getting more lightweight and smaller, and the thickness of such a molded article is getting thinner. Accordingly, to respond to this, there is a case that the resin composition for use in such molding is desired to have more excellent mechanical characteristics and flame resistance than conventional resin compositions.

#Contents of the present invention will be detailed below. Note that a word “ . . . to . . . ” in this specification will be used to indicate a range including the lower and upper limits represented by the numerals given therebefore and thereafter, respectively.

#The resin composition of the invention comprising 100 parts by weight of a thermoplastic polyester resin (A), 5 to 40 parts by weight of a phosphinate (B), and an organosiloxane (X); wherein the phosphinate (B) is a calcium salt or aluminium salt of phosphine acid of which the anion part is represented by the formula (1) or (2); which comprises, as the organosiloxane (X), 1.5 to 10 parts by weight of an organosiloxane compound (X-1) or 0.01 to 5 parts by weight of an organosiloxane polymer (X-2), relative to 100 parts by weight of the thermoplastic polyester resin (A); and wherein the organosiloxane compound (X-1) comprises organic groups bonding to a silicon atom directly or through an oxygen atom, wherein 40 mole % or more of the organic groups are an aryl group, and the organosiloxane polymer (X-2) is in the form of solid at 25° C.

#wherein R1's and R2 each independently are an alkyl group having 1 to 6 carbon atoms, or an aryl group which may have a substituent; R1's may be the same or different to each other; R3's are an alkylene group having 1 to 10 carbon atoms, an arylene group which may have a substituent, or a combination of at least two thereof; R3's may be the same or different to each other; and n is an integer of 0 to 4.