| 摘要 |
PURPOSE:To obtain a container having both transparency and high crystallinity and both transparency and heat resistance under heating atmosphere by treating a sheet obtd. from a polybutylene terephthalate copolymer wherein a specified amt. of a specified comonomer unit is incorporated at a specified condition and molding and processing it. CONSTITUTION:A copolymerized polyester resin wherein 5-35mol% repeating unit consists of an ester unit consisting of terephthalic acid or an ester-forming derivative thereof and a diol of formula and the remaining repeating unit consists of an ester unit consisting of terephthalic acid or an ester-forming derivative thereof and 1,4-butane diol is melt-molded and quenched to prepare a sheet with a low crystallinity and then, it is aged at a cold crystallization temp. or lower to prepare a sheet with a cold heat capacity or crystallization or 5.0J/g or larger and finally, it is thermally molded. In the formula, R is a group selected from -CH2CH2-, -CH2CH(CH3)- and -CH(CH3)CH2 and may be the same or different each other; each of n is an integer of 0-2 and they are the same or different each other. |
