| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of producing a polyester resin having high flowability while keeping its own mechanical strength properties such as tensile rupture-inducing distortion strength without impairing its own polycondensation reactivity and quality and being slight in fear of thickening (gelation).SOLUTION: A method for producing a polyester (resin) comprises: an esterification step of carrying out an esterification reaction and/or transesterification reaction between a dicarboxylic acid component comprising terephthalic acid or its ester-forming derivative and a diol comprising 1,4-butanediol, and a polycondensation step of carrying out a polycondensation reaction of the resultant oligomer obtained in the esterification step, wherein a fatty acid ester compound composed of the corresponding fatty acid and polyhydric alcohol and/or a polycarboxylic acid ester compound composed of the corresponding polycarboxylic acid and alcohol are incorporated into the reaction system. |
