| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a polyester film having superior hydrolysis resistance and capable of holding adhesion to an adherend and withstand voltage properties for a long period of time.SOLUTION: The method of manufacturing a polyester film includes: an extrusion step of melt extruding a polyester material resin containing at least one kind selected from a group consisting of aluminum and an aluminum compound as polymerization catalyst and having intrinsic viscosity of ≥0.71 and ≤0.90 by an extruder, wherein the discharge amount (Q/N; Q represents an extrusion amount per unit time [kg/hr] and N represents screw rotation speed [rpm]) of the extruder is set to 50 to 80% of the theoretical maximum discharge amount; an unoriented film forming step of forming an unoriented film by cooling and solidifying the melt extruded polyester resin on a cast roll; a biaxial orientation step of biaxially orienting the formed unoriented film in a longitudinal direction and a lateral direction; and a thermal fixing step of thermally fixing the oriented film formed by the biaxial orientation. |
