Magnetic recording medium using magnetic powder having a core portion and an outer layer portion including a rare earth element and magnetic recording cassette

摘要

A magnetic recording medium comprising a non-magnetic support, at least one primer layer formed on one surface of the non-magnetic support, comprising a non-magnetic powder and a binder resin, at least one magnetic layer formed on the primer layer, comprising a magnetic powder and a binder resin, and a back layer formed on the other surface of the non-magnetic support, wherein the magnetic powder contained in the uppermost layer of the magnetic layer is a rare earth metal-iron type magnetic powder of substantially spherical or ellipsoidal particles comprising a rare earth element and iron or a transition metal which comprises iron, and has a number average particle size 5 to 50 nm and an average axis ratio of 1 to 2, and the total thickness of the magnetic recording medium is less than 6 μm. This magnetic recording medium can achieve an excellent block error rate, which cannot be realized with magnetic recording media comprising conventional acicular magnetic powders.