Patent ID: 8318842

Claim:
A titanium-containing PET copolyester resin, suitable for use in producing a refillable large volume container having an inner volume greater than 10 litters and capably returnable and refillable up to 20 loops of returning, comprising polyethylene terephthalate as a major component and contains titanium component in an amount of 10-25 ppm based on the total PET copolyester weight, X mole % of isophthalic acid based on the PET copolyester, Y mole % of diethylene glycol based on the PET copolyester, and Z mole % of 2,6-naphthalene dicarboxylic acid based on the PET copolyester, wherein X, Y, Z conforms to the following conditions: 0 ≦X≦ 2.5; 1.0 ≦Y≦ 2.5; 0 ≦Z≦ 2.5; 2.5 ≦X+Y+Z≦ 7.5; and the PET copolyester has an intrinsic viscosity of 0.72-0.90 dl/g and a maximum amount of heat released during crystallization transition of the copolyester through a differential scanning calorimeter analysis at a given heating rate of 20° C./min being less than 10 joules/gram.