| 摘要 |
<p>A biaxially oriented polyester film for magnetic recording media which contains cross-linked polymer particles (A) having a mean particle diameter (dA) of 0.8 to 1.6 νm in an amount ranging from 0.0005 wt.% to 0.001 wt.% (both exclusive), inert particles (B) having a mean particle diameter (dB) of 0.4 to 0.8 νm in an amount of 0.1 to 0.8 wt.% and inert inorganic particles (C) having a mean particle diameter (dC) of 0.01 to 0.3 νm and a Moh's hardness of 7 or above in an amount of 0.05 to 1.0 wt.%, with the dA/dB ratio ranging from 1.5 to 3, and which has an SRz/SRa ratio of 20 or above (wherein SRz is the three-dimensional ten-point average surface roughness of the film and SRa is the three-dimensional center line average surface roughness thereof). This film is excellent in windability, chipping resistance and durability in traveling and can be produced at a low cost, thus being useful particularly as base films for magnetic recording media for high-speed duplicators.</p> |
