Weatherable block copolyestercarbonate compositions

A resinous composition having improved weatherability comprising the following and any reaction products thereof:

• a) at least one block copolyestercarbonate comprising organic carbonate blocks alternating with arylate blocks, said carbonate blocks having a degree of polymerization of at least about 3 and comprising structural units derived from bisphenol A, and said arylate blocks having a degree of polymerization of at least about 4 and comprising structural units derived from unsubstituted resorcinol and a mixture of isophthalate and terephthalate residues in a ratio of about 0.25-4.0:1 isophthalate to terephthalate;
• b) at least one poly(butylene terephthalate);
• and
• c) at least one acrylonitrile-styrene-butylacrylate copolymer.

A resinous composition having improved weatherability comprising the following and any reaction products thereof:

• d) at least one block copolymer comprising moieties of the formula
• wherein each R1 is independently halogen or C1-4 alkyl, each R2 is independently a divalent organic radical, p is 0-3, m is at least about 3 and n is at least about 4;
• e) at least one poly(alkylene dicarboxylate);
• and
• f) at least one impact modifier.