| 摘要 |
One aspect of the present invention provides a method for production of a polyester resin film comprising melt extruding a polyester resin into a sheet shape, cooling and solidifying the polyester resin sheet on a casting drum, then longitudinally stretching the polyester resin sheet in a longitudinal direction, and then passing the longitudinally stretched polyester resin film through a transverse stretching apparatus to transversely stretch the longitudinally stretched polyester resin film in a transverse direction, wherein Xc, Tc, Ts and Te satisfy the formulas of: Tc≰(Ts+Te)/2+2.66Xc≰Tc+60 (1) and 2≰Xc≰30 (2), in which Xc (%) indicates a crystallinity of the film after the longitudinal stretching, Tc (° C.) indicates a crystallization temperature of the film after the longitudinal stretching, Ts (° C.) indicates a film surface temperature at an entrance of a stretching zone of the transverse stretching apparatus, and Te (° C.) indicates a film surface temperature at an exit of the stretching zone of the transverse stretching apparatus. |
