| 摘要 |
PURPOSE:To improve running durability, more specifically the running durability after long-period preservation by incorporating polycarbonate polyurethane and specific fatty acid ester compd. as a binder into a magnetic layer. CONSTITUTION:The polycarbonate polyurethane and the fatty acid ester compd. expressed by the formula are incorporated as the resins for the binder to be used for forming the magnetic layer into said layer. In the formula, R denotes a hydrocarbon group of >=6C; R<1> denotes a hydrogen atom or hydrocarbon group; R<2> and R<3> denote hydrocarbon groups which may be the same or different from each other. The wear resistance of the recording medium during the traveling in contact with members such as magnetic head and guide poles is thereby greatly improved and since the coefft. of friction to the members of the traveling system is decreased, the running durability of the magnetic layer is extremely improved. |
