| 摘要 |
PURPOSE:To provide a method for producing a highly crystalline polyester film or sheet excellent in transparency and a method for producing the aforementioned film or sheet. CONSTITUTION:A film or sheet obtained by melt molding a copolyester resin composed of 5-30mol% recurring units composed of ester units formed from terephthalic acid or its ester-forming derivative and a cycloalkylene diol and residual recurring units mainly composed of ester units formed from terephthalic acid or its ester-forming derivative and 1,4-butanediol is quenched to prepare a film or sheet having low crystallinity. The resultant film or sheet is aged at a specific temperature and further heat-treated at a specified temperature. |
