BIAXIALLY ORIENTED POLYESTER FILM AND METHOD FOR PRODUCING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a biaxially oriented polyester film that excels in thermal dimensional stability and suppresses the occurrence of "blackout" when a display device such as a liquid crystal display is mounted with the film as a polarizer protection film, a retardation film for a circularly polarizing plate, and a transparent electrode film.SOLUTION: There is provided a biaxially oriented polyester film that satisfies following conditions (a) and (b). (a) The biaxially oriented polyester film has a leaning angle of the main orientation axis of 30° or more and 60° or less to the longitudinal direction thereof. (b) The biaxially oriented polyester film has a thermal shrinkage of 0.0% or more and 1.0% or less in the longitudinal direction and a thermal shrinkage of 0.0% or more and 1.0% or less in the width direction after being subjected to a heat treatment for 30 minutes at 150°C.SELECTED DRAWING: None