Patent ID: 8344093

Claim:
A continuous method of producing an aliphatic polyester, comprising, in the following order: (I) mixing an aliphatic dicarboxylic acid and an aliphatic diol, to obtain a slurry; (II) esterifying the dicarboxylic acid and aliphatic diol, to produce an esterification reaction product; and (III) polycondensing the esterification reaction product, thereby obtaining the aliphatic polyester, wherein, during (I), a temperature range of the slurry is from the coagulation point of the aliphatic diol to 80° C., and a moisture content in the slurry is from 0.01 to 10% by weight, based on a total weight of the slurry, wherein the aliphatic diol comprises 70 mol % or more of 1,4-butanediol, and the aliphatic dicarboxylic acid comprises 70 mol % or more of succinic acid, and wherein the aliphatic dicarboxylic acid in the slurry is in the form of particles having an average particle diameter D(50) and particle diameter D(90) in 90% of an accumulated volume percentage curve of particle diameter that satisfy formulae (1) and (2): 1 μm≦ D (50)≦500 μm (1) D (90)/ D (50)≦2.5 (2).