| 摘要 |
PROBLEM TO BE SOLVED: To provide a biaxially oriented polyester film enhanced in Young's modulus, low in surface roughness, reduced in thickness irregularity and reduced in surface damage. SOLUTION: A biaxially oriented polyester film is characterized by that the Young's modulus in the longitudinal and lateral directions thereof is 5.8 GPa or more, the surface roughness (Ra) of at least the single surface thereof is 2-15 nm and the number of coarse surface damages with a length of 2 mm or more thereof is 20 pieces/m2 or less. Further, the number of fine surface damages with a height of 0.81μm or more of the film is preferably 10 pieces/100 cm2 or less. |
