| 摘要 |
PURPOSE: To obtain a biaxially oriented laminated polyester film having excellent wear resistance when the film is fed on a metal guide at a high speed by laminating a polyester film and specifying the surface roughness. CONSTITUTION: The biaxially oriented laminated polyester film is formed by laminating a polyester A on one surface of a polyester B. The film has 5 to 40nm of the centerline surface roughness of the surface of the laminated part, 0.5wt.% or less of the content of the surface layer of the surface, 15μm or less of the surface protrusion interval in the longitudinal direction of the surface, and 1.665 or more of the longitudinal refractive index of the surface layer part of the surface. As the orienting method, it is effective to use a sequentially biaxially orienting of orienting first in the longitudinal direction and then in the lateral direction. The longitudinal orienting is conducted at the higher temperature by 10 deg.C or higher than the glass transition temperature Tg of the polyester. |
