Patent ID: 7855267

Claim:
A film or sheet comprising a polyester composition comprising at least one polyester which comprises: (a) a dicarboxylic acid component comprising: i) 80 to 100 mole % of terephthalic acid residues; ii) 0 to 20 mole % of aromatic dicarboxylic acid residues having up to 20 carbon atoms; and iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues having up to 16 carbon atoms; and (b) a glycol component comprising: i) 20 to 30 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues; and ii) 70 to 80 mole % of 1,4-cyclohexanedimethanol residues, wherein the total mole % of the dicarboxylic acid component is 100 mole %, and the total mole % of the glycol component is 100 mole %; wherein the inherent viscosity of the polyester is 0.60 to 0.75 dL/g as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a concentration of 0.5 g/100 ml at 25° C.; wherein said polyester has a Tg of 100 to 130° C.; wherein the polyester has a notched Izod impact strength of at least 7.5 ft-lb/inch at 23° C. according to ASTM D256 with a 10 mil notch in a ⅛ inch thick bar; wherein the melt viscosity of the polyester is less than 10,000 poise as measured at 1 radian/second on a rotary melt rheometer at 290° C.; and wherein said polyester composition contains no polycarbonate.