公开(公告)号：US5470645A

公开(公告)日：1995-11-28

申请号：US156972

申请日：1993-11-24

申请人： Toshihiko Oguchi ,  Hajime Takeuchi ,  Minori Murano

发明人： Toshihiko Oguchi ,  Hajime Takeuchi ,  Minori Murano

IPC分类号： C09D5/23 ,  C09D175/00 ,  C09D175/04 ,  G11B5/716 ,  G11B5/73 ,  G11B5/00

CPC分类号： G11B5/716 ,  Y10S428/90 ,  Y10T428/24942 ,  Y10T428/25 ,  Y10T428/256 ,  Y10T428/257 ,  Y10T428/265 ,  Y10T428/31609

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.

摘要翻译： 磁记录介质包括非磁性基材，含有用于长波长范围记录的磁粉的下磁性层和含有用于在短波长范围内记录的磁粉的上磁层。 通过向上磁性层添加中值粒径为0.05〜0.3μm的小粒子磨料，通过适当选择上层磁性层中所含的树脂粘合剂的种类和量，可以获得令人满意的磨损效果 。 即使使用粒径小的研磨剂，也不需要增加其量，可以获得这种效果。 此外，通过使用该磨料，即使上部磁性层较薄，上部磁性层和下部磁性层的表面也能够平滑化。 因此，可以提供在宽波长范围内具有高记录和再现特性以及高运行耐久性的优异的磁记录介质。 特别地，可以提高短波长范围内的记录和再现特性。 可以使用六角铁氧体粉末作为在短波长范围内记录的磁粉。