| 摘要 |
<p>The invention relates to a copolyester having an inherent viscosity ranging from about 0.4 to about 1.4 dl/g and a cold crystallization temperature ranging from about 120 to about 160 °C. Such copolyesters comprise the reaction product of a glycol component comprising from about 85 to about 100 mole % of 1,3-propanediol, a dibasic acid component comprising from about 85 to about 100 mole % of a dibasic acid selected from terephthalic acid, napthalenedicarboxylic acid, anhydrides, acid chlorides, and lower alkyl esters thereof, and mixtures thereof, and from about 5 to about 15 mole % of a comonomer. The presence of the comonomer lowers the crystallization temperature of the copolyesters according to the invention such that amorphous preforms can be easily molded from the copolyesters. Such amorphous preforms are readily stretch blow molded into bottles or other container shapes or may be injection molded into various shapes or objects or extruded into film or sheeting. Accordingly, in another embodiment the invention relates to film and containers prepared from the copolyester composition described above. The films and containers according to the invention have improved gas barrier properties such that they may be used for packaging perishable goods, such as beverages, foods, and cosmetics.</p> |
