| 摘要 |
PURPOSE:To improve durability by specifying the packing ratio of magnetic hexagonal ferrite powder in a magnetic layer. CONSTITUTION:The packing ratio of the magnetic hexagonal ferrite powder in the magnetic layer is specified to <=35vol%, by which a binder component for binding this kind of the magnetic powder onto a substrate, polishing agent for reinforcing the magnetic layer and lubricating agent component to impart a good lubricating effect to the magnetic layer are thoroughly incorporated into the magnetic layer and the durability is substantially improved. The holes in the magnetic layer are specified to >=20vol%, by which a cushioning property is provided to the magnetic layer itself and the impact by the sliding contact with the magnetic head is absorbed. A substantial amt. of the lubricating agent is held in the holes thereof by which the durability is additionally improved. The durability is further improved by selecting the grain size of the magnetic hexagonal ferrite powder at relatively large sizes of >=0.05mum. |
