发明授权
US5672423A Magnetic recording medium having an underlayer containing three
different powders
失效
具有含有三种不同粉末的底层的磁记录介质
- 专利标题: Magnetic recording medium having an underlayer containing three different powders
- 专利标题(中): 具有含有三种不同粉末的底层的磁记录介质
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申请号: US378366申请日: 1995-01-25
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公开(公告)号: US5672423A公开(公告)日: 1997-09-30
- 发明人: Hiroo Inaba , Kiyomi Ejiri
- 申请人: Hiroo Inaba , Kiyomi Ejiri
- 申请人地址: JPX Kanagawa
- 专利权人: Fuji Photo Film Co., Ltd.
- 当前专利权人: Fuji Photo Film Co., Ltd.
- 当前专利权人地址: JPX Kanagawa
- 优先权: JPX4-40509 19920131
- 主分类号: G11B5/738
- IPC分类号: G11B5/738 ; G11B5/68
摘要:
A magnetic recording medium containing a support having thereon in order, a non-magnetic layer unit and a magnetic layer unit, said magnetic recording medium having been produced by providing a non-magnetic layer unit containing at least one non-magnetic layer and comprising a non-magnetic powder dispersed in a binder on a non-magnetic support followed by providing, while the non-magnetic layer is still wet, a magnetic layer unit containing at least one magnetic layer and comprising a ferromagnetic powder dispersed in a binder on the non-magnetic layer, wherein the mean thickness of the magnetic layer is 1.0 .mu.m or less and the non-magnetic powder in the non-magnetic layer comprises (A) a tabular non-magnetic powder having a tabular size of from 0.01 to 0.3 .mu.m and an aspect ratio of from 3 to 20, or an acicular non-magnetic powder having a long axis of from 0.05 to 0.25 .mu.m and an aspect ratio of from 3 to 15, (B) a carbon black powder having a mean particle size of from 0.01 to 0.04 .mu.m and (C) a powder component having a larger mean particle size than the mean particle size of either powders (A) or (B).