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°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°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.
一种聚酯
树脂,由聚酯
树脂片(A)和聚酯
树脂细粒(B)组成,其组成与(A)相同,通过10.5目筛的比例为0.1-300ppm,其中环状三聚体在290℃的温度下熔融60分钟后增加的比例不超过0.30 wt%;一种聚酯
树脂,其特征在于,在290℃的温度下熔融60分钟后,环状三聚体以不超过0.30 wt%的比例增加,聚酯
树脂中Na、Ca、Mg和/或Si的含量为0.001-5ppm,这些含量的总和不超过10ppm;及其生产方法。根据本发明的聚酯
树脂,拉伸吹塑模具、热定型模具、真空成型模具等模具在片材成型、瓶子成型等过程中的沾污较少,因此可以长时间持续成型,从而轻松生产出大量具有优异透明度的成型物品。因此,可以获得成品透明度和耐热性都很好的中空制品。