POLYESTER FILM AND METHOD FOR PRODUCING SAME

摘要

Provided are a polyester film that satisfies formulas (1) to (4), and a method for producing the polyester film. W/1000 < [(Ss1 - Ss2)/CS1/100] < 2W (1) 0 < (Ss1 - Ss2) < 0.5 (2) -1 < (Ss1 + Ss2 + SCT)/3 < 3 (3) 0 < Cs1 < 0.2 (4) [Ss1 represents the machine direction thermal shrinkage rate (%) of the film at an edge having a large machine direction thermal shrinkage rate among the edges in the film width direction. Ss2 represents the machine direction thermal shrinkage rate (%) of the film at an edge having a small machine direction thermal shrinkage rate among the edges in the film width direction. SCT represents the machine direction thermal shrinkage rate (%) at the center of the film in the film width direction. CS1 represents the maximum value (m) of the magnitude of curvature at the edge having a large machine direction thermal shrinkage rate among the film edges in the film width direction. W represents the film width (m)].