Polyester compositions which comprise cyclobutanediol and certain thermal stabilizers, and/or reaction products thereof

A polyester composition comprising:

• (I) at least one polyester which comprises:
• (a) a dicarboxylic acid component comprising:
• (i) 70 to 100 mole % of terephthalic acid residues;
• (ii) 0 to 30 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 cyclohexanedimethanol residues;
• and
• (II) at least one thermal stabilizer chosen from at least one of alkyl phosphate esters, aryl phosphate esters, mixed alkyl aryl phosphate esters, reaction products thereof, or mixtures thereof;
• wherein the weight ratio of total tin atoms to total phosphorus atoms in the final polyester is 2-10:1;
• wherein the total mole % of the dicarboxylic acid component is 100 mole %,
• wherein the total mole % of the glycol component is 100 mole %;
• wherein the inherent viscosity of the polyester is from 0.60 to 0.75 dL/g as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a concentration of 0.25 g/50 ml at 25° C.;
• and
• wherein the polyester has a Tg from 100 to 130° C;
• wherein said 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 said 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.