A resin composition including an aromatic polyester resin and having high levels of hydrolysis resistance and moldability is provided. The resin composition includes an aromatic polyester resin having a terminal carboxyl group content of not more than 30 eq/ton (component A), a cyclic carbodiimide compound having at least two carbodiimide rings, each having only one carbodiimide group (component B), and a polyvalent hydroxyl group-containing compound having a hydroxyl value of not less than 200 (component C).
Disclosed is a cyclic carbodiimide compound useful as an end-capping agent for polymer compounds. The cyclic carbodiimide compound is represented by the following formula (i):
wherein X is a specific divalent group or tetravalent group, q is 0 when X is a divalent group, while q is 1 when X is a tetravalent group, and Ar
1
to Ar
4
are selected from aromatic groups each independently optionally substituted with a group that serves as X.