Patent ID: 7300998

Claim:
A polyester resin of which the polymerizability parameter satisfies the following formula (A-1), the stability parameter satisfies the following formula (B-1), and the metal content parameter further satisfies the following formula (C-1): V ssp≧ 0.025( dl/g·h ) (A-1) wherein V ssp is calculated from the intrinsic viscosity of polyester resin, and the intrinsic viscosity of polyester resin after solid polycondensation of this polyester resin at 220° C. under nitrogen atmosphere for any hours between 2 hours and 12 hours, by the following calculation formula: V ssp =([ IV] 1 -[ IV] 0 )/ T wherein [IV] 0 and [IV] 1 represent intrinsic viscosities (dl/g) before and after the solid polycondensation, respectively, and T represents solid polycondensation time (h); ΔAA≦7.0 (ppm) (B-1) wherein ΔAA is calculated from the acetaldehyde amount contained originally in the polyester resin, and the acetaldehyde amount contained in a preform obtained by molding this polyester resin with an injection molding machine at a cylinder temperature of 265 to 275° C. for 26±1 seconds of a molding cycle, by the following calculation formula: ΔAA=[AA] 1 -[AA] 0 wherein [AA] 0 and [AA] 1 represent acetaldehyde contents (ppm by weight) before and after the molding, respectively; M≦50 (ppm) (C-1) wherein M represents the total amount (ppm by weight) of the metal atoms contained in the polyester resin.