Patent ID: 7572493

Claim:
A preform having an open ended mouth forming portion, an intermediate body forming portion, and a closed base forming portion, and comprising a PET Copolymer comprising a diol component having repeat units from ethylene glycol and diethylene glycol and a diacid component having repeat units from terephthalic acid and naphthalenedicarboxylic acid, wherein, based on 100 mole percent of the diol component and 100 mole percent of the diacid component, respectively, the total combined amount of repeat units from diethylene glycol and repeat units from naphthalenedicarboxylic acid present in the PET Copolymer is in an amount from about 0.1 mole percent to about 2.8 mole percent, and the preform has an intrinsic viscosity less than 0.77 dL/g and a stretch ratio in the range from about 8 to about 13.