MANUFACTURING METHOD FOR POLYESTER RESIN FILM, POLYESTER RESIN FILM MANUFACTURED THEREBY, ANTIREFLECTION FILM, AND DIFFUSION FILM

摘要

PROBLEM TO BE SOLVED: To provide a manufacturing method for a polyester resin film suppressed in the occurrence of thickness irregularity, and to provide the polyester resin film manufactured by this manufacturing method. SOLUTION: In the manufacturing method for the polyester resin film by extruding a polyester resin into a sheetlike shape in a molten state to cool and solidify the extrudate on a casting drum 12 and stretching the extrudate in a longitudinal direction while passing the stretched extrudate through a lateral stretching device 30 to stretch the same in a lateral direction, when the degree of crystallization of the film after longitudinal stretching is set to Xc(%), the crystallizing temperature of the film after longitudinal stretching is set to Tc(°C), the surface temperature of the film at the inlet of the stretching zone of the lateral stretching device is set to Ts(°C) and the surface temperature of the film at the outlet of the stretching zone of the lateral stretching device is set to Te(°C), the formula (1):Tc≤(Ts+Te)/2+2.66Xc≤Tc+60 and the formula (2):2≤Xc≤30 are satisfied. COPYRIGHT: (C)2009,JPO&INPIT