| 摘要 |
<p>The purpose of the present invention is to provide a polyester film which has excellent transparency after a thermal processing, is not susceptible to the precipitation of cyclic oligomers, and also has excellent heat resistance and durability in use applications including display members for which high quality is required. According to the present invention, a polyester film is provided, which comprises a polyethylene terephthalate resin, said film being characterized in that the polyethylene terephthalate resin has an intrinsic viscosity of 0.60 dl/g or more and the ratio (WCy3/WCy4) of the weight fraction (WCy3) of a cyclic trimeric oligomer to the weight fraction (WCy4) of a cyclic tetrameric oligomer in the film is 5 or less.</p> |
