Biaxially oriented laminated polyester film

摘要

A biaxially oriented, laminated polyester film comprising a polyester substrate layer (A) and a polyester surface layer (B) laminated on at least one surface of the polyester substrate layer (A), the polyester surface layer (B) containing inert particles, having a thickness of 0.02 to 3 mu m, having a surface roughness Ra of 3 to 40 nm and having a surface roughness Ra fluctuation ratio of 5 % or less when measured along a distance of 500 mm in the film width direction. The surface roughness of the polyester surface layer (B) of this film is uniform in the width direction, and the laminated polyester film gives an excellent form of a roll and pancakes of slit films from said laminated polyester film.