METHOD FOR PRODUCING POLYESTER AND POLYESTER RESIN

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a polyester having an improved color tone and polymerizability with which a side reaction during a polycondensation reaction is suppressed. SOLUTION: The method for producing the polyester comprises (A) a step of carrying out an esterification reaction or a transesterification reaction of a dicarboxylic acid or a dialkyl dicarboxylate and a diol as main raw materials in the presence of a catalyst and producing an oligomer in≥90% esterification ratio or transesterification ratio and (B) a polycondensation step of continuously carrying out the polycondensation reaction of the oligomer in a molten state by using multistage reaction vessels. The method for producing the polyester is characterized as satisfying TMAX>T(ω) when the internal temperature of a vessel having the highest internal temperature in (B) the polycondensation step is TMAX°C and the internal temperature of the final vessel is T(ω)°C. COPYRIGHT: (C)2005,JPO&NCIPI