发明名称 |
POWDER FOR SUBLAYER OF COATING TYPE MAGNETIC RECORDING MEDIUM AND MAGNETIC RECORDING MEDIUM COMPRISING THE SAME |
摘要 |
A powder for an underlayer of a coating-type magnetic recording medium comprises acicular iron oxide particles having an average major axis length in the range of 20-200 nm, has a specific surface area measured by the BET method of 30-100 m<SUP>2</SUP>/g and has a powder pH of not greater than 7. The underlayer powder preferably contains 0.1-5.0 wt. % of P and optionally contains an amount of R (where R represents one or more rare earth elements, defined as including Y) such that R/Fe expressed in atomic percentage (at. %) is 0.1-10 at. %. The iron oxide powder enhances the properties required of a powder for forming the underlayer of a multi-layer structure coating-type magnetic recording tape, most notably the surface smoothness and strength of the tape. |
申请公布号 |
EP1492089(A4) |
申请公布日期 |
2005.04.13 |
申请号 |
EP20030746417 |
申请日期 |
2003.04.02 |
申请人 |
DOWA MINING CO., LTD. |
发明人 |
MATSUMOTO, KAZUYUKI;INOUE, KENICHI;INOUE, KEN |
分类号 |
C01G49/06;G11B5/738;(IPC1-7):G11B5/738;G11B5/70 |
主分类号 |
C01G49/06 |
代理机构 |
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代理人 |
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