| abstract |
(57) [Summary] Polyester capable of suppressing an increase in the amount of cyclic trimers contained in polyester resin and an increase in cyclic trimers during remelting, and hardly generating mold stains and die stains during molding. Provide resin. A polyester containing terephthalic acid and ethylene glycol as main components, wherein at least one metal element M selected from the group consisting of antimony, titanium, germanium, tin, and zinc contained in the polyester; A polyester resin having a molar ratio to sulfonic acid groups N contained in the polyester of N / M ≧ 0.01. |