| 摘要 |
PROBLEM TO BE SOLVED: To provide a supporting body excellent in dimensional stability and rigidity to be used for a magnetic recording medium such as a magnetic tape, in particular, to provide such a supporting body that when the body is used for a magnetic recording medium, the medium realizes a high-density magnetic recording medium causing no track shift even after long-term storage under the conditions of high temperature and high humidity, having excellent traveling durability and dimensional stability and showing preferable electromagnetic conversion characteristics. SOLUTION: The supporting body for a magnetic recording medium is produced by preparing a biaxially oriented polyester film made of polymers containing polyester and polyimide and having 2 to 6.5μm film thickness, 1.5 to 20 nm surface roughness Ra on one film surface (A) and 5 to 50 nm surface roughness Ra on the other surface (B) and by forming a reinforcing film made of one or more kinds of metal material selected from metals, semimetals, alloys and oxides and composite materials of these on at least the surface (B). The biaxially oriented polyester film contains polyester and polyimide. |
