| abstract |
The present invention provides a process for the preparation of a biodegradable lactic acid-based polyester composition excellent in thermal stability, storage stability, flexibility, heat resistance, mechanical and physical properties and moldability which comprises kneading a lactic acid-based polyester and a polyester consisting of dicarboxylic acid component(s) and diol component(s) with a chelating agent, an acidic phosphoric acid ester, a molecular weight increasing agent, etc., and then devolatilizing the kneaded mixture. The present invention also provides a molding process of the foregoing lactic acid-based polyester composition. A process for the preparation of a lactic acid-based polyester composition is provided, which comprises melt-kneading a lactic acid-based polyester (A), a polyester (B) consisting of dicarboxylic acid component(s) and diol component(s) and a chelating agent and/or acidic phosphoric acid ester (C) in an amount such that the weight ratio (A)/(B) is from 99/1 to 10/90 and the proportion of (C) is 0.001 to 5 parts by weight based on 100 parts by weight of the sum of (A) and (B). A process for molding a lactic acid-based polyester composition is also provided, which comprises kneading a lactic acid-based polyester (A) and a polyester (B) consisting of dicarboxylic acid component(s) and diol component(s) with a chelating agent and/or acidic phosphoric acid ester (C), and then molding the material. |