To provide a favorable polyethylene naphthalate which has a well balance among the haze, the transparency, the hue and the thermal stability when the polyethylene naphthalate is bottle-molded.
This polyethylene naphthalate is a polyester comprising a naphthalenedicarboxylic acid as a main acid component and ethylene glycol as a main glycol component. The polyethylene naphthalate has an inherent viscosity of 0.40-0.90 dL/g and contains a cobalt compound, a magnesium compound, a calcium compound, a phosphorus compound and an antimony compound as polymerization catalysts in each amount which satisfies respectively all of the following equations (1) to (5): 0.08≤Co≤1.2 mole (1), 2.0≤(Mg+Ca)≤6.0 mole (2), 1.3≤(Mg/Ca)≤6.0 (3), 1.0≤P/(Co+Ca+Mg)≤1.5 (4), 0.8≤Sb≤3.0 mole (5), wherein each symbol of metal elements represents the amount of each metal in number of moles relative to 106 g of the amount of the above-noted acid component.
SATO KIMIHIKO
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