Polyester film

摘要

A polyester film contains a polyester having an intrinsic viscosity (IV) in the range from 0.65 to 0.8 and an antioxidant. The polyester has an endothermic high temperature peak at a temperature of (A) DEG C and an endothermic low temperature peak at a temperature of (B) DEG C, both peaks being measured by differential scanning calorimetry (DSC), and the value of (A - B) is in the range from 25 DEG C to 50 DEG C. The polyester film is suitable for use an insulation film, exhibiting improved ageing properties.