发明授权
US5470645A Magnetic recording medium having two magnetic layers comprising magnetic
powder and binder
失效
磁记录介质具有包含磁性粉末和粘合剂的两个磁性层
- 专利标题: Magnetic recording medium having two magnetic layers comprising magnetic powder and binder
- 专利标题(中): 磁记录介质具有包含磁性粉末和粘合剂的两个磁性层
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申请号: US156972申请日: 1993-11-24
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公开(公告)号: US5470645A公开(公告)日: 1995-11-28
- 发明人: Toshihiko Oguchi , Hajime Takeuchi , Minori Murano
- 申请人: Toshihiko Oguchi , Hajime Takeuchi , Minori Murano
- 申请人地址: JPX Kanagawa JPX Tokyo
- 专利权人: Kabushiki Kaisha Toshiba,Konica Corporation
- 当前专利权人: Kabushiki Kaisha Toshiba,Konica Corporation
- 当前专利权人地址: JPX Kanagawa JPX Tokyo
- 优先权: JPX3-114440 19910520
- 主分类号: C09D5/23
- IPC分类号: C09D5/23 ; C09D175/00 ; C09D175/04 ; G11B5/716 ; G11B5/73 ; G11B5/00
摘要:
A magnetic recording medium comprises a non-magnetic base material, a lower magnetic layer containing a magnetic powder for recording in a long wavelength range, and an upper magnetic layer containing a magnetic powder for recording in a short wavelength range. By adding a small particle abrasive with a median diameter in the range from 0.05 to 0.3 .mu.m to the upper magnetic layer and by properly selecting the type and amount of a resin binder contained in the upper magnetic layer, a satisfactory abrasion effect can be obtained. This effect can be obtained, even if the abrasive with a small particle diameter is used without necessity of increase of the amount thereof. In addition, by using this abrasive, even if the upper magnetic layer is thin, the surfaces of the upper magnetic layer and the lower magnetic layer can be smoothened. Therefore, an excellent magnetic recording medium having high recording and reproduction characteristics in a wide wavelength range and high running durability can be provided. In particular, the recording and reproduction characteristics in a short wavelength range can be improved. A hexagonal ferrite powder can be used as a magnetic powder for recording in a short wavelength range.
公开/授权文献
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