公开(公告)号：US6040041A

公开(公告)日：2000-03-21

申请号：US22673

申请日：1998-02-12

申请人： Klaus Gotz ,  Helmut Jakusch ,  Werner Loch ,  Erich Hoffmann ,  Hans-Georg Gottmann ,  Hans-Joachim Jenor ,  Johann Voit

发明人： Klaus Gotz ,  Helmut Jakusch ,  Werner Loch ,  Erich Hoffmann ,  Hans-Georg Gottmann ,  Hans-Joachim Jenor ,  Johann Voit

IPC分类号： G11B5/706 ,  G11B5/716

CPC分类号： G11B5/716 ,  Y10S428/90 ,  Y10T428/24975 ,  Y10T428/256 ,  Y10T428/257

摘要： A magnetic recording medium consisting of a nonmagnetic substrate and at least two magnetizable layers which are applied thereon and contain metal oxides as magnetic pigment is described, the pigment of the upper layer having a higher BET value than that in the lower layer. According to the invention, the upper layer has a thickness in the range of 3-5 .mu.m when dry and the lower layer a thickness in the range of 1.1-3 .mu.m when dry. Particularly advantageous results are obtained when the magnetic pigment of the upper layer is cobalt-doped .gamma.--Fe.sub.2 O.sub.3 and that of the lower layer is acicular CrO.sub.2. With the double-layer recording medium obtained according to the invention, in particular the output level at low frequencies is improved without the frequency curve showing the usual depression in the middle.

摘要翻译： 描述了由非磁性基底和至少两个可磁化层组成的磁记录介质，其上涂有金属氧化物作为磁性颜料，上层颜料的BET值高于下层。 根据本发明，当干燥时，上层的厚度为3-5μm，下层的干燥时的厚度为1.1-3μm。 当上层的磁性颜料是钴掺杂的γ-Fe2O3并且下层的磁性颜料是针状的CrO 2时，可以获得特别有利的结果。 利用根据本发明获得的双层记录介质，特别是在低频下的输出电平得到改善，而没有显示中间通常凹陷的频率曲线。