| 摘要 |
The present invention is directed to a blend comprising a normally-solid polyestercarbonate copolymer or terpolymer and a normally-solid aromatic hydrocarbylene polycarbonate resin, the polyestercarbonate copolymer or terpolymer containing a plurality of repeating units corresponding to the Formula I: I wherein each R is independently aromatic hydrocarbylene or inertly-substituted aromatic hydrocarbylene, each R' is independently meta- or para-phenylene and X is a number from 0.05 to 10. The invention is characterized in that the polyestercarbonate copolymer or terpolymer comprises from 10 to 26 weight percent of the blend, the polycarbonate resin comprises from 90 to 74 weight percent of the blend, and the mole percent ester in the blend ranges from 10 to 22 based upon the sum of the number of moles of ester and carbonate groups. The blends of this invention exhibit mechanical and thermal properties very similar to a synthesized 29,368-F polyestercarbonate copolymer or terpolymer having the same overall ratio of ester to carbonate groups. Surprisingly, these blends exhibit toughness superior to that of any of the component polymers at temperatures below -25.degree.C and improved Izod impact strength over a wide range of temperatures where the notch has a 5 mil (0.13 mm) radius. These blends are used in applications where a tough rigid thermoplastic is required. |
