ALS SUBSTRAT FUER MAGNETISCHE AUFZEICHNUNGSMEDIEN GEEIGNETE POLYESTERFOLIE
摘要
A polyester film suitable for use as a substrate for magnetic recording media, characterized in that said polyester film is a biaxially oriented polyester film having an average refractive index &upbar& n and a planar orientation DELTA P, which respectively satisfy the following equations [I] and [II]: &upbar& n>/=1.600 [I] DELTA P</=(1.43x &upbar& n)- 2.128 [II] and the surface roughness of the film is 0.015 mu m or lower.
