ORIENTED POLYESTER FILM

摘要

PURPOSE:To prepare a polyester film excellent in the wear and mar resistance and suitable for a magnetic recording medium by incorporating a small specified amt. of Al2O3 particles having a specified specific surface area and synthesized by a specific production method into the polyester film. CONSTITUTION:The title film contains 0.01-2wt.% Al2O3 particles having a specific surface area of 70-100m<2>/g and synthesized by the thermal decomposition of ammonium alum. The film is excellent in the friction and wear characteristics with various substrates and is suitably used in many applications including a base film for magnetic recording. The use of the Al2O3 particles serves to avoid substantially the wear of an apparatus in the slurry preparation step which has been a frequently arising problem with formerly used high-hardness particles.