Copolyester til stöbning af flasker

摘要

A copolyester for molding a bottle which comprises 95 to 87 mol% of naphthalenedicarboxylic acid and 5 to 13 mol% of terephthalic acid as dicarboxylic acid components and a diol component consisting essentially of ethylene glycol, has an acetaldehyde content of 20 ppm or less and an intrinsic viscosity of 0.40 to 0.85 dl/g, and produces acetaldehyde in an amount of 30 ppm or less when the copolyester is kept molten with stirring at 300 DEG C for 5 minutes.