| 摘要 |
PROBLEM TO BE SOLVED: To provide a biaxially oriented polyester film suited for a capacitor dielectric which achieves high electrostatic capacity, while maintaining high withstand voltage characteristic. SOLUTION: Provided is a manufacturing process for the biaxially oriented polyester film in which the film thickness t measured by a gravimetric method is 2.5μm or less, the thickness unevennessΔt/t in the longitudinal direction of the film is 0.15 or less, and the relationship between the mean particle size d50 (μm) of the particle A having the largest mean particle size and the film thickness t satisfies the formula (1) 0.5t≤d50≤1.0t, characterized in that a plate or a cover is installed in the vicinity of the ground point at which a meltdown state polyester sheet adheres to a cooling roll. COPYRIGHT: (C)2010,JPO&INPIT |
