| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetic recording medium which attains both miniaturization of a ferromagnetic powder and high packing of a magnetic layer and is excellent in flatness of the surface of the magnetic layer and electromagnetic conversion characteristic. SOLUTION: A magnetic recording medium has a non magnetic support, a lower non magnetic layer on the one surface of the non magnetic support, and an upper magnetic layer on the lower non magnetic layer, wherein the lower non magnetic layer includes carbon black, non magnetic inorganic powder other than the carbon black, and binder resin while the upper magnetic layer includes the ferromagnetic powder and the binder resin having a polarized group. The ferromagnetic powder is the ferromagnetic metal powder with an average length of long axis of 10 to 50 nm or hexagonal crystal ferrite magnetic powder with an average plate span of 5 to 40 nm, and the binder resin of the upper magnetic layer having the polarized group includes the polarized group with quantity ranging from 0.18 to 0.35μmol/m<SP>2</SP>per unit specific surface (according to BET method) of the ferromagnetic powder. COPYRIGHT: (C)2009,JPO&INPIT
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