Magnetic recording medium
View Patent ↗In one aspect, the magnetic recording medium comprises a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder and a binder in this order on a nonmagnetic support. The quantity of metal ions comprised in the nonmagnetic powder is equal to or less than 40 ppm/g. In a second aspect, the magnetic recording medium comprises a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder and a binder in this order on a nonmagnetic support. The abrasiveness of the magnetic layer against a ferrite bar is equal to or less than 2×10 −5 μm/m. In both aspects, the quantity of metal ions extracted from the magnetic layer is equal to or less than 0.5 ppm/m 2 ·100 mL.
1. A magnetic recording medium comprising a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder and a binder in this order on a nonmagnetic support, wherein
the quantity of metal ions extracted from said magnetic layer by washing with water is equal to or less than 0.5 ppm/m 2 ·100 mL, and
the quantity of metal ions comprised in said nonmagnetic powder is equal to or less than 40 ppm/g, and wherein said magnetic layer has a surface electrical resistivity ranaina from 10 +6 to 10 +8 Ω.
2. The magnetic recording medium according to claim 1 , wherein the abrasiveness of said magnetic layer against a ferrite bar is equal to or less than 2×10 −5 μm/m.
3. The magnetic recording medium according to claim 1 , which has a backcoat layer on the surface of the nonmagnetic support, opposite to the surface having the magnetic layer.
4. The magnetic recording medium according to claim 1 , which is employed in a magnetic recording and reproduction device in which a magnetoresistive reproduction head is employed.
5. The magnetic recording medium according to claim 4 , wherein said magnetoresistive reproduction head is a shielded magnetoresistive reproduction head.
6. A method of reproducing a signal magnetically recorded on a magnetic recording medium with a magnetoresistive reproduction head, wherein
said magnetic recording medium is the magnetic recording medium according to claim 1 .
7. The method according to claim 6 , wherein said magnetoresistive reproduction head is a shielded magnetoresistive reproduction head.