| 摘要 |
<p>A polyester film suited for optical recording media, which has a photo elasticity coefficient up to 1.2 x 10-3 mm2/kgf, a surface roughness, Rt, up to 100 nm, and an average distance between surface projections, Sm, of 20 νm or more. The film does not cause scattering or interference of light and produces no optical distortion even when heated or pressed, thus being useful as a support layer or a cover layer of optical recording media such as optical cards, optical discs, optical recording tapes, etc.</p> |
