发明名称 |
MAGNETIC RECORDING MEDIUM FOR A VIDEO TAPE RECORDER AND A METHOD FOR PREPARING THE SAME |
摘要 |
A magnetic recording medium for a video tape recorder is disclosed, comprising a nonmagnetic support having thereon in the following order an under magnetic layer containing ferromagnetic particles of metal oxide and an upper magnetic layer containing ferromagnetic particles of metal oxide, wherein said under magnetic layer contains the ferromagnetic particles having a specific surface area by a BET method of from 26 to 50 m2/g and a coercive force (Hc1) of from 500 to 1,000 Oe; said upper magnetic layer contains the ferromagnetic particles having a specific surface area by a BET method of from 30 to 60 m2/g and a coercive force (Hc2) of from 600 to 1,200 Oe; the dry thickness of the upper magnetic layer is from 0.1 to 1.0 mu m; and the coercive force (Hc2) of the ferromagnetic particles for the upper magnetic layer is higher than the coercive force (Hc1) of the ferromagnetic particles for the under magnetic layer.
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申请公布号 |
US5082729(A) |
申请公布日期 |
1992.01.21 |
申请号 |
US19880259668 |
申请日期 |
1988.10.19 |
申请人 |
FUJI PHOTO FILM CO., LTD. |
发明人 |
NISHIDA, TETSUJI;SAITO, SHINJI;CHINO, NAOYOSHI |
分类号 |
C09D5/23;G11B5/714;G11B5/716 |
主分类号 |
C09D5/23 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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