Oriented semi-crystalline polyester films, method for their manufacture and their use as support for magnetic coatings.

摘要

The invention relates to oriented films having the set of following properties: - F5 MD >/= 18 daN/mm<2> - F5 TD >/= 10 daN/mm<2> - EMD >/= 800 daN/mm<2> - ETD >/= 400 daN/mm<2> - EMD + ETD >/= 1200 daN/mm<2> - RMD 105 </= 1.5 % - RMD 150 </= 5.2 % - Rr TD/F5 TD </= 2.2 and to their production by a film-forming method employing a drawing step in inverse sequence preceded by a longitudinal drawing step carried out under conditions leading to a uni-axially drawn film having an axial birefrigence less than or equal to 0.015 and an average refractive index less than or equal to 1.5775.