Patent ID: 6797788
Filing Date: 2004-09-28
Classification: C08K,C08L

Abstract:
A process for preparation of a thermoplastic polyester composition, comprising:passing a thermoplastic aliphatic polyester into an extruder successively comprising a polymer loading zone, a melting zone, a homogenization zone, a reaction zone in which molten thermoplastic aliphatic polyester reacts with a radical generator employed in a quantity ranging from 0.01 to 0.2% by wt based on the thermoplastic aliphatic polyester, and a discharge zone, wherein the temperature of the loading zone is &lE;20Â° C., the temperature in the melting zone and in the homogenization zone is &gE; the melting temperature of the polymer and &lE; the temperature at which the half-life period of the radical generator is ten times greater than the dwell time of the material in each of said zones and the temperature of the reaction zone is &gE; the temperature at which the half-life period of the radical generator is &lE;the dwell time of the material in this zone, thereby producing an extrudate having an RMFI value ranging from 1.1 to 2.5; and obtaining the extruded polyester.