Polyester resin and production method thereof

摘要

A polyester resin comprising a polyester resin chip (A) and a polyester resin fine particle (B) which has the same composition as the (A) and which passes through a 10.5 mesh screen in a proportion of 0.1 - 300 ppm, wherein a cyclic trimer increases in a proportion of not more than 0.30 wt% upon melting at a temperature of 290 DEG C for 60 minutes; a polyester resin characterized in that a cyclic timer increases in a proportion of not more than 0.30 wt% upon melting at a temperature of 290 DEG C for 60 minutes, and the contents of Na, Ca, Mg and/or Si in the polyester resin is 0.001 - 5 ppm and the total of these contents is not more than 10 ppm; and production methods thereof. According to the polyester resin of the present invention, mold such as stretch blow mold, heat setting mold, vacuum forming mold and the like are less stained in sheet forming, bottle forming and the like, so that forming can be continued for a long time to easily produce a multitude of formed articles with superior transparency. As a result hollow articles having superior transparency and heat resistance of the finish part can be obtained.