Process for producing a polyester

Abstract

A method for producing a polyester includes: a) preparing a first monomer represented by Formula (1) for example—bis(β-hydroxyethyl) terephthalate (BHET); and b) preparing a second monomer represented by Formula (2) represented by Formula (2)—2-(2-hydroxyethoxy)ethyl 2-hydroxyethyl terephthalate (BHEET). The prepared first and second monomer are then mixed to form a mixture, and then the mixture is subjected to a pre-polymerization reaction at a first temperature not higher than 230° C. to form a prepolymer while a glycol compound represented by Formula (3) wherein R independently represents hydrogen, a C1-C6 linear or branched alkyl group, or phenyl; is continuously removed by distillation. The method also includes subjecting the prepolymer to a polymerization reaction at a second temperature higher than the first temperature to obtain the polyester.

Dependencies are inferred from the claim text.