To obtain a magnetic recording medium in which the surface smoothness and stiffness of the nonmagnetic base layer can be improved, in which, when a magnetic recording layer is formed on the nonmagnetic base layer, the magnetic layer has higher surface smoothness, excellent stiffness, small transmittance for light and more excellent durability, and in which corrosion of an acicular metal magnetic powder essentially consisting of iron dispersed in the magnetic recording layer can be suppressed.
This magnetic recording medium consists of a nonmagnetic supporting body, nonmagnetic base layer formed on the nonmagnetic supporting body, and a magnetic recording layer formed on the nonmagnetic base layer. In this medium, the nonmagnetic particle powder is a titanium oxide particle powder having ≤0.3 μm average particle size, ≥15 m2/g BET specific surface area, ≤230 ppm soluble sodium salt content calculated as Na, ≤150 ppm soluble sulfate content calculated as SO4, and ≥8 pH of the powder. The magnetic particle powder is an acicular metal magnetic powder essentially consisting of iron having 0.05 to 10 wt.% aluminum content calculated as Al.
IWASAKI KEISUKE
HAYASHI KAZUYUKI
