ALIPHATIC POLYESTER AND PROCESS FOR PRODUCTION THEREOF

摘要

An aliphatic polyester which is produced without a chain extender such as isocyanate or carbonate and is excellent in moldability in injection, blow molding or extrusion, heat stability, and mechanical properties such as tensile characteristics. The aliphatic polyester comprises aliphatic diol units, aliphatic dicarboxylic acid units and units of an organic acid having a pKa value of 3.7 or below at 25°C, and has a carbonate linkage content of less than 1 mole% based on the whole of the monomer units constituting the polyester, a urethane linkage content of less than 0.06 mole%, a content of aliphatic monooxymonocarboxylic acid units of less than 0.02 mole%, a content of phosphorus resulting from one or more phosphorus compounds selected from among organic phosphinic acids, organic phosphonic acids, and hydrogenphosphates of less than 10<-9> mole%, and a reduced viscosity (etasp/C) of 1.6 or above.