| US 7,592,413 B2 | ||
| Manufacture of aromatic polyester | ||
| Joel D. Citron, Wilmington, Del. (US); David Neil Marks, Newark, Del. (US); and Marion G. Waggoner, Landenberg, Del. (US) | ||
| Assigned to E. I. du Pont de Nemours and Company, Wilmington, Del. (US) | ||
| Filed on Sep. 08, 2006, as Appl. No. 11/517,848. | ||
| Claims priority of provisional application 60/719376, filed on Sep. 22, 2005. | ||
| Prior Publication US 2007/0066793 A1, Mar. 22, 2007 | ||
| Int. Cl. C08G 63/00 (2006.01) | ||
| U.S. Cl. 528—308.3 [528/272; 528/308.6; 528/308.1; 528/271; 528/308] | 9 Claims |
| 1. 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.
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