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 stretching the vertically stretched sheet in the lateral direction. In the method, the glass transition temperature of the polyester resin [Tg (°C)], 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 (30) [Ts (°C)] and the temperature of the surface of the film at the outlet part of the stretching zone in the lateral stretching apparatus (30) [Te (°C)] satisfy the requirements expressed by the following formulae (1) to (3). 3 <= Xc <= 20 (1) Tg-10 <= Ts <= Tc+20 (2) Tc-10 <= Te <= Tc+80 (3).