Patent ID: 8440762

Claim:
A composition comprising, based on the total weight of the composition: (a) from 10 to 80 wt. % of a polybutylene terephthalate; (b) from 10 to 80 wt. % of a copolyestercarbonate component, comprising a first copolyestercarbonate having a number average molecular weight of 15,000 to less than 28,000 Daltons, and a second copolyestercarbonate having a number average molecular weight of more than 28,000 to 40,000 Daltons, wherein a weight ratio of the first polyestercarbonate to the second polyestercarbonate is 75:25 to 25:75, and wherein each copolyestercarbonate comprises structural estercarbonate units of the formula: wherein each R 1 is independently the same or different C 6-30 aromatic group, each T is independently the same or different C 2-16 alkylene group, and x is the mole % of ester units in the copolyestercarbonate based on the total mole % of ester and carbonate units and is 5 to 10, wherein the ester and carbonate units represent at least 90 mole % of the polyestercarbonate; (c) from 3 to 30 wt. % of a particulate filler; (d) from 0.1 to 10 wt. % of a fluoropolymer; (e) from 3 to 25 wt. % of a polymeric impact modifier; (f) from 0 to 5 wt. % of an additive selected from the group consisting of an antioxidant, mold release agent, colorant, quencher, stabilizer, and combination thereof; and (g) from 0 to 30 wt. % of a polycarbonate; wherein melt viscosity is at least 15% lower, as compared to a composition in which the first and second copolyestercarbonates are replaced by bisphenol A polycarbonates of the same number average molecular weights, wherein the melt viscosity is less than 230 Pa·s, as determined in accordance with ISO 11443 at 265° C. at a shear rate of 1500 s −1 and wherein a 4-mm thick bar molded from the composition retains at least 80% of its notched Izod impact strength, as determined in accordance with ISO 180 at 23° C., as compared to the same composition in which the first and second copolyestercarbonates are replaced by bisphenol A polycarbonates of the same number average molecular weights.