METHOD FOR PRODUCTION OF POLYESTER RESIN FILM, AND POLYESTER RESIN FILM, ANTIREFLECTIVE FILM AND DIFFUSION FILM PRODUCED BY THE METHOD

摘要

Disclosed is a method for producing a polyester resin film, which comprises the steps of: melt-extruding a polyester resin into a sheet; cooling the sheet on a casting drum to solidify the sheet; stretching the sheet in the vertical direction; and passing the vertically stretched sheet through a lateral stretching apparatus to stretch the sheet in the lateral direction. In the method, the degree of crystallinity of the film after the vertical stretching[Xc (%)], the crystallization temperature of the film after the vertical stretching[Tc (°C)], the temperature of the surface of the film at the inlet part of the stretching zone in the lateral stretching apparatus[Ts (°C)]and the temperature of the surface of the film at the outlet part of the stretching zone in the lateral stretching apparatus[Te (°C)]satisfy the requirements expressed by the following formulae (1) and (2). Tc <= (Ts+Te)/2+2.66Xc <= Tc+60 (1) 2 <= Xc <= 30 (2).