| 摘要 |
<p>The present invention provides an improved substrate film for magnetic tapes. The base film is a biaxially oriented PENBB film, i.e. a biaxially oriented copolyester film containing the structural unit (I) (bibenzoate, BB). Such particle containing films exhibit improved modulus in the machine and transverse direction and show surface protrusions such that their height crosses the line of log10 y = -18x + 3.7 twice.</p> |
