Patent ID: 7196123

Claim:
A polyester block copolymer composition which comprises thermally-kneading 100 parts by weight of a polyester block copolymer (P1) obtained by a reaction of a crystalline aromatic polyester (A1) with lactones (B) with 0.5–5.0 parts by weight of a mono or more functional epoxy compound (C) and 0.01–3.0 parts by weight of an oxalic bisbenzylidene hydrazide (G), wherein the epoxy compound (C) comprises the combination of at least one compound (c1) selected from the group consisting of (c1-1) the compound represented by the following formula (I) and (c1-2) an adduct of ε-caprolactone monomer to 3,4-epoxycyclohexylmethyl-3′,4′-epoxcyclohexanecarboxylate, and at least one compound selected from the group consisting of the compounds represented by the following formulae (III)–(V) and wherein “n1” is 1–5 and “n2” is 0–5.