Patent ID: 7332561
Filing Date: 2008-02-19
Classification: C08G,D01F,Y10T

Abstract:
1. A process for producing poly(trimethylene terephthalate) composition particles comprising the following steps (1) to (4): (1) a step of reacting terephthalic acid and/or a lower alcohol ester derivative of terephthalic acid with 1,3-propanediol in the presence of a catalyst having polycondensation activity to form 1,3-propanediol ester of terephthalic acid and/or a polymer thereof; (2) a step of granulating the 1,3-propanediol ester of terephthalic acid and/or a polymer thereof obtained in the step (1) to produce composition particles having a particle size of 3 mm or less, and a particle weight of less than 1 mg/particle; (3) a step of heating the composition particles to subject the particles to solid-state polymerization, whereby the intrinsic viscosity is increased by 0.1 dl/g or more; and (4) a step wherein the composition particles obtained in the step (3) are subjected to a step comprising contacting the particles with a polar compound of at least one substance selected from the group consisting of water, methanol, phosphoric acid, hydrogen chloride, sulfuric acid and ammonia at a temperature of 50° C. or above and for 60 minutes or less in order to deactivate a part of or the entire polycondensation activity of the catalyst.