发明申请
- 专利标题: MAGNETIC RECORDING MEDIUM AND PROCESS FOR PRODUCING THE SAME
- 专利标题(中): 磁记录介质及其制造方法
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申请号: US12056568申请日: 2008-03-27
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公开(公告)号: US20080241600A1公开(公告)日: 2008-10-02
- 发明人: Hiroyuki Tanaka , Tsutomu Ide , Osamu Inoue
- 申请人: Hiroyuki Tanaka , Tsutomu Ide , Osamu Inoue
- 申请人地址: JP Tokyo
- 专利权人: TDK Corporation
- 当前专利权人: TDK Corporation
- 当前专利权人地址: JP Tokyo
- 优先权: JP2007-094976 20070330
- 主分类号: G11B5/66
- IPC分类号: G11B5/66 ; B05D5/12
摘要:
The present invention provides a magnetic recording medium wherein a fine non-magnetic inorganic powder, the dispersibility of which is improved, is used to improve the surface smoothness of a lower non-magnetic layer, thereby giving an excellent surface smoothness of an upper magnetic layer and electromagnetic conversion property; and a production process thereof. A magnetic recording medium comprising at least a non-magnetic support, a lower non-magnetic layer on one surface of the non-magnetic support, and an upper magnetic layer on the lower non-magnetic layer, wherein the upper magnetic layer contains at least a ferromagnetic powder, and a binder resin material, and the lower non-magnetic layer contains at least carbon black, iron oxide, and a binder resin material, and the iron oxide has an average major axis length of 30 to 100 nm, and a specific surface area based on the BET method of 80 to 120 m2/g, and the iron oxide contains moisture in an amount per unit specific surface area of 0.13 to 0.25 mg/m2.