| 摘要 |
<p>Disclosed is a polyester resin particle which enables to obtain a molded article having high transparency by thermoforming, while suppressing fusion bonding of particles when polyester prepolymer particles are subjected to crystallization or a heat treatment such as a solid-phase polycondensation without decreasing the solid-phase polycondensation rate. Specifically disclosed is a method for producing a polyester resin wherein a polyester prepolymer particle obtained by melt polycondensation of a dicarboxylic acid component and a diol component is subjected to a hot water treatment and a heat treatment in this order. When the hot water treatment is performed, a polyester prepolymer particle having an intrinsic viscosity of not less than 0.10 dL/g but not more than 1.0 dL/g and a density of not more than 1.36 g/cm3 is brought into contact with a hot water having a temperature higher than the glass transition temperature of the polyester prepolymer particle but lower than 100°C under the conditions satisfying the following formula (1). 40 <= (T-Tg)t <= 6000 (1) (In the formula, t represents hot water treatment time (second), T represents hot water temperature (°C), and Tg represents glass transition temperature of polyester prepolymer particle (°C).)</p> |
