Abstract: A thermoplastic molding composition comprising poly(butylene terephthalate), a reinforcing component, and a mixed flame retardant containing melamine pyrophosphate and an aromatic phosphate oligomer in selected proportions exhibits improved flame resistance, relatively low melt viscosity for good melt processability, and good physical properties, particularly tensile strength and tensile elongation.

Abstract: This invention relates to flame retardants for polyester and polyamide compositions, and specifically relates to compositions containing (1) about 30 to about 70 weight percent of a polyester or a synthetic, aliphatic polyamide or a mixture thereof; (2) about 15 to about 40 weight percent of glass or mineral reinforcing agent; and (3) a flame retardant of (a) about 20 to about 30 weight percent of melamine phosphate and up to about 10 weight percent of a charring catalyst; (b) about 15 to about 30 weight percent of melamine phosphate, up to about 10 weight percent of a charring catalyst and up to about 10 weight percent of a char former; (c) about 5 to about 45 weight percent of melamine pyrophosphate; (d) about 15 to about 30 weight percent of melamine pyrophosphate and up to about 10 weight percent of a charring catalyst; (e) about 15 to about 30 weight percent of melamine pyrophosphate, up to about 10 weight percent of a charring catalyst and up to about 10 weight percent of a char former, or (f) about 20