| 摘要 |
PROBLEM TO BE SOLVED: To provide a biaxially oriented polyester film for a magnetic recording medium useful as a base film of the medium particularly for a rapid duplicator to be manufactured by a low manufacturing cost with excellent windability, cutting resistance and feeding durability. SOLUTION: The biaxially oriented polyester film for a magnetic recording medium comprises 0.0001 to 0.03 wt.% of inert particles A each having a mean particle size dA of 0.8 to 1.6μm and Mohs' hardness of less than 3, 0.1 to 0.8 wt.% of inert particles B each having a mean particle size dB of 0.4 to 0.8μm and Mohs' hardness of 3 to less than 8, 0.05 to 1.0 wt.% of inert particles C each having a mean particle size dC of 0.01 to 0.3μm and Moh's hardness of 8 or more, in such a manner that a difference of the Moh's of the particles A from that of the particles B is 2 or more and a difference of the Mohs' of the particles B from that of the particles C is 3 or more.
|
