BIAXIALLY ORIENTED POLYESTER FILM EXCELLENT IN TAKING-UP PROPERTIES

摘要

PURPOSE:To obtain a biaxially oriented polyester film excellent in winding properties and capable of being taken up in a roll shape having a good wound posture while satisfying high recording density, long-time recording properties and the enhancement of quality as a film for magnetic recording. CONSTITUTION:Recessed parts with a mean diameters 5-50mum are formed to at least the single surface of a biaxially oriented polyester film in an occupying area ratio of 2-50% so as to make it possible to uniformly disperse air taken in between wound films over the entire surface of the film.