Patent ID: 7592413

Claim:
A process for the production of an aromatic polyester, comprising, contacting, in an extruder at elevated temperature one of the following: (a) one or more diesters of aliphatic carboxylic acids and dihydroxyaromatic compounds, and one or more aromatic dicarboxylic acids; or (b) one or more diesters of aliphatic carboxylic acids and dihydroxyaromatic compounds, one or more aromatic dicarboxylic acids, and one or more esters of aliphatic carboxylic acids and aromatic hydroxyacids; or (c) one or more esters of aliphatic carboxylic acids and aromatic hydroxyacids; wherein said esters and/or diesters are preformed before entering said extruder; provided that during said contacting aliphatic carboxylic acid byproduct is removed from said extruder and a residence time in said extruder is less than 20 minutes.