COPOLYESTER, AND HOLLOW CONTAINER AND STRETCHED FILM MADE THEREFROM

摘要

PURPOSE:To prepare a copolyester which causes less staining of molds and is improved in thermal and mechanical strengths by reacting terephthalic acid with a diol comprising ethylene glycol, cyclohexanedimethanol and diethylene glycol. CONSTITUTION:A dicarboxylic acid component comprising terephthalic acid and a diol component comprising ethylene glycol, 0.5-3.5mol% cyclohexanedimethanol and 1.0-2.5mol% diethylene glycol are subjected to direct esterification under pressure, and the temperature is raised while gradually reducing the pressure to effect the polycondensation of the formed esters in the presence of a condensation catalyst containing a Ge compound into a copolyester having an intrinsic viscosity of 0.60-1.50dl/g, a Ge atom content of 30-60wt.ppm and a cyclic trimer content of 0.35wt.% or less.