| 摘要 |
PROBLEM TO BE SOLVED: To provide a biaxially oriented polyester film for a magnetic recording medium excellent in windability, scraping resistance and running durability and useful particularly as a base film of a magnetic recording medium for a high-speed duplicator. SOLUTION: This film comprises 0.001 to 0.03wt.% crosslinked high-molecular particles A having an average particle size dA of 0.8 to 1.6μm, 0.1 to 0.8wt.% inert particles B having an average particle size dB of 0.4 to 0.8μm, 0.02 to 0.5wt.% spherical inert particles C having an average particle size dC of 0.1 to 0.5μm, and 0.01 to 0.3wt.% inert inorganic particles D having an average particle size dD of 0.1 to 0.3μm and a Mohs hardness of at least 7, and dA, dB, dC and dD satisfies the following relationship: dA>dB>dC>dD. |
