Patent ID: 7605222

Claim:
A copolyetherimide having a glass transition temperature of at least 240° C., and a weight average molecular weight as determined by gel permeation chromatography relative to polystyrene standards of at least 40,000 grams per mole, and copolyetherimide comprising structural units of the formulas (I) and (II) and structural units of the formula (III), wherein R 1 independently at each occurrence a divalent aromatic radical derived from bisphenol A or 4,4′-biphenol; R 2 is a divalent aromatic radical having formula (IV) wherein R 3 is independently at each occurrence halogen, a C 1 -C 10 aliphatic radical, a C 3 -C 12 cycloaliphatic radical, or a C 3 -C 15 aromatic radical, and “a” and “b” are independently at each occurrence integers from 0 to 4; said copolyetherimide being characterized by a mole percentage of structural units derived from 4,4′-biphenol in a range from about 55% to about 85% of all bisphenol-derived structural units present in the copolyetherimide composition; said copolyetherimide being characterized by a mole percentage of structural units derived from bisphenol A in a range from about 45% to about 15% of all bisphenol-derived structural units present in the copolyetherimide composition; said copolyetherimide being characterized by a total mole percentage of structural units derived from bisphenol A or 4,4′-biphenol of at least 95% of all bisphenol-derived structural units present in the copolyetherimide composition; said copolyetherimide being characterized by a total amount of bisimide-containing structural units, said structures I, II, and III representing at least 95 percent of the total amount of bisimide-containing structural units; said copolyetherimide being characterized by a molar ratio of structural subunits (V) and (VI) said molar ratio being in a range from about 85 mole percent (V) to about 99 mole percent (V) and about 15 mole percent (VI) to about 1 mole percent (VI).