Containers of a copolyester, copolyesters composition for this purpose and their representation

摘要

A container formed from a copolyester composition which comprises a copolyester containing 80 to 95 mol% of terephthalic acid and 20 to 5 mol% of 2,6-naphthalenedicarboxylic acid as acid components and ethylene glycol as a glycol component, wherein catalyst metals of a calcium compound, magnesium compound and cobalt compound are contained in the copolyester in such amounts that satisfy all the following expressions (1) to (4) based on the total of the whole acid component of the polymer:$\[ \text{0 Ca ≦ 35 (mmol\%)} \]$$\[ \text{0 Mg ≦ 80 (mmol\%)} \]$$\[ \text{40 ≦ (Mg + Ca) ≦ 90 (mmol\%)} \]$$\[ \text{0 ≦ Co ≦ 15 (mmol\%)} \]$;The above polyester container is excellent in gas barrier property, ultraviolet light screening property, hot water resistance, hue and transparency, is not whitened and has a small content of aldehyde.