To ensure satisfactory electromagnetic transducing characteristics, to ensure satisfactory running durability even when the total thickness of a medium is reduced and to attain high density and high capacity recording.
A magnetic layer with iron oxide-base magnetic powder dispersed in a binder as an upper layer is formed on a non-magnetic layer with non-magnetic powder dispersed in a binder as a lower layer to obtain the objective magnetic recording medium. The non-magnetic powder has <0.2 μm major axis size and the ratio of the major axis size of the non-magnetic powder to the minor axis size is higher than the ratio of the major axis size of the magnetic power to the minor axis size. The non-magnetic power is hematite powder surface-modified with an Al or Si compd. A vinyl chloride copolymer having an average polymn. degree of ≤180 and contg. a metallic sulfonate as polar groups accounts for ≥50 wt.% of the binder contained in the lower layer. Binders accounting for ≥50 wt.% of the binder contained in the upper and lower layers are the same.
SATO HIROYUKI
KIKAWADA JUN
Next Patent: DISCOID MAGNETIC RECORDING MEDIUM