| 主权项 |
1. A magnetic recording medium,
which comprises a nonmagnetic layer comprising nonmagnetic powder and binder on a nonmagnetic support and a magnetic layer comprising ferromagnetic powder, binder, and abrasive on the nonmagnetic layer, wherein the nonmagnetic layer satisfies conditions 1 to 4 below: condition 1: a ratio of as total area accounted for by voids observed to an area of a region being observed falls within a range of 13.0% to 25.0% in a sectional image taken by a scanning electron microscope; condition 2: R+σr is less than or equal to 58.0 nm and R−σr is greater than or equal to 21.0 nm when denoting an average value of diameters of corresponding circles for voids observed in the sectional image as R, denoting a standard deviation of the diameters of the corresponding circles as σr, and denoting R and σr in units of nm; condition 3: N+σn is less than or equal to 185 voids/μm2 and N−σn is greater than or equal to 120 voids/μm2 when denoting an average number of voids observed per μm2 unit area of the region being observed in the sectional image as N, denoting a standard deviation of the number as σn, and denoting N and σn in units of voids/μm2; condition 4: a thickness of the nonmagnetic layer is greater than or equal to 0.20 μm. |
