Patent ID: 8476381

Claim:
A polyester resin (PE) produced via reaction of a crystalline polyoxyalkylene polyol, and a polycarboxylic acid (F), the crystalline polyoxyalkylene polyol having a number average molecular weight of 500 to 20,000 and produced by a method comprising: performing ring-opening polymerization of an alkylene oxide (a) with a salen complex used as a catalyst (B) in a condition that an amount of the salen complex is 6 to 100 parts by weight with respect to 100 parts by weight of said alkylene oxide (a), the salen complex being represented by the formula (1): wherein R 1 to R 4 each independently represent a hydrogen atom, or an aliphatic, alicyclic, aromatic, or aromatic aliphatic hydrocarbon group, or a halogen atom, or any pair of the R 1 to R 4 may be linked together to form a ring; a hydrogen atom or hydrogen atoms bonded to a carbon atom in the hydrocarbon group may be substituted or unsubstituted; R 5 to R 12 each independently represent a hydrogen atom, or an aliphatic, alicyclic, aromatic, or aromatic aliphatic hydrocarbon group, or a halogen atom, or any adjacent pair of the R 5 to R 12 may be linked together to form a ring; a hydrogen atom or hydrogen atoms bonded to a carbon atom in the hydrocarbon group may be substituted or unsubstituted; M represents a metal atom belonging to any one of groups III to XIII; L represents a ligand; n represents an integer of 1 or 2, and when n is 2, one ligand L of two Ls may be the same as or different from the other, or the formula (2): wherein R 13 to R 16 each independently represent a hydrogen atom, or an aliphatic, alicyclic, aromatic, or aromatic aliphatic hydrocarbon group, or a halogen atom, or any pair of the R 13 to R 16 may be linked together to form a ring; a hydrogen atom or hydrogen atoms bonded to a carbon atom in the hydrocarbon group may be substituted or unsubstituted; and R 5 to R 12 , M, L, and n represent the same as defined for the formula (1).