PREPARATION OF POLY(TRIMETHYLENE TEREPHTHALATE) WITH LOW LEVEL OF DI(1,3 PROPYLENE GLYCOL).

摘要

A process of preparing poly(trimethylene terephthalate) containing less than 2.0 mole % of DPG comprising: (a) providing a molar amount of 1,3 propanediol: C1 to C4 dialkyl ester of terephthalic acid of 1.2:1 to 1.9:1, (b) reacting the 1,3 propanediol with the C1 to C4 dialkyl ester of terephthalic acid to form bis(3 hydroxypropyl)terephthalate monomer in the presence of 10 100ppm (as titanium metal) of an organic titanate catalyst, by weight of the poly(trimethylene terephthalate), and (c) polymerizing the bis(3 hydroxypropyl)terephthalate monomer to obtain the poly(trimethylene terephthalate); and poly(trimethylene terephthalate) produced by the process.