| abstract |
Provided are an aliphatic polyester carbonate having biodegradability and having a content of carbonate unit of at least 5 mol%, a weight-average molecular weight of at least 100,000, a melt viscosity of 2,000-50,000 poises at 190°C and under a load of 60 kg and a melting point of 70-180°C, and a process for producing said aliphatic polyester carbonate which comprises reacting an aliphatic dihydroxy compound with an aliphatic dibasic acid in the presence of an ester exchange catalyst to obtain an oligomer and then reacting the oligomer with a diaryl carbonate in the presence of the ester exchange catalyst. As catalyst a combination of a zirconium or Hafnium compound with an YHrium, Lanthanum, zinc or tin compound is used. A phosphorus compound may be added to the aliphatic polyester carbonate for the purpose of stabilization. |