Magnetic recording medium
View Patent ↗The present invention relates to a magnetic recording medium comprising a magnetic layer on at least one side of a nonmagnetic substrate, the magnetic layer containing magnetic particles of a CuAu type or Cu 3 Au type ferromagnetic ordered phase, wherein a conductive layer is provided on at least one side of the nonmagnetic substrate.
1. A magnetic recording medium comprising a magnetic layer on at least one side of an inorganic nonmagnetic substrate, the magnetic layer containing magnetic particles of a CuAu-type or Cu 3 Au-type ferromagnetic ordered phase produced by a liquid phase method, wherein a conductive layer containing polyvinylbenzene sulfonate, polyvinyl benzyl trimethyl animonium chloride, or a quaternary salt polymer is provided on at least one side of the inorganic nonmagnetic substrate, the conductive layer having a thickness of 10 to 400 nm.
2. The magnetic recording medium according to claim 1 , wherein the thickness of the conductive layer is 20 to 400 nm.
3. A magnetic recording medium comprising a magnetic layer on at least one side of an inorganic nonmagnetic substrate, the magnetic layer containing magnetic particles of a CuAu-type or Cu 3 Au-type ferromagnetic ordered phase produced by a liquid phase method, wherein a conductive layer containing a conductive metal oxide is provided on at least one side of the inorganic nonmagnetic substrate, the conductive layer having a thickness of 10 to 400 nm.
4. The magnetic recording medium according to claim 1 , wherein the conductive layer is disposed between the inorganic nonmagnetic substrate and the magnetic layer.
5. The magnetic recording medium according to claim 1 , wherein the conductive layer is disposed on the inorganic nonmagnetic substrate on a side opposite to the magnetic layer.
6. The magnetic recording medium according to claim 1 , wherein the conductive layer is disposed on an edge of the inorganic nonmagnetic substrate.
7. The magnetic recording medium according to claim 3 , wherein the conductive metal oxide is selected from ZnO Al 2 O 3 , In 2 O 3 , SiO 2 , MgO, BaO, MoO 3 , V 2 O 5 and complex oxides thereof.
8. The magnetic recording medium according to claim 3 , wherein the conductive metal oxide has a volume resistivity of not more than 10 7 Ωcm.
9. The magnetic recording medium according to claim 1 , wherein the magnetic recording medium has a surface electric resistance of not more than 10 10 Ω/sq.
10. The magnetic recording medium according to claim 1 further comprising another magnetic layer, a nonmagnetic layer, or a back layer on a side opposite to the magnetic layer.
11. The magnetic recording medium according to claim 1 further comprising a protection film on the magnetic layer.
12. The magnetic recording medium according to claim 3 , wherein the conductive layer is disposed on an edge of the inorganic nonmagnetic substrate.
13. The magnetic recording medium according to claim 1 , wherein the CuAu-type or Cu 3 Au-type ferromagnetic ordered phase produced by a liquid phase method is selected from FeNi, FePd, FePt, CoPt, CoAu, Ni 3 Fe, FePd 3 , Fe 3 Pt, FePt 3 , CoPt 3 , Ni 3 Pt, CrPt 3 and Ni 3 Mn.
14. The magnetic recording medium according to claim 3 , wherein the CuAu-type or Cu 3 Au-type ferromagnetic ordered phase produced by a liquid phase method is selected from FeNi, FePd, FePt, CoPt, CoAu, Ni 3 Fe, FePd 3 , Fe 3 Pt, FePt 3 , CoPt 3 , Ni 3 Pt, CrPt 3 and Ni 3 Mn.
15. The magnetic recording medium according to claim 7 , wherein the CuAu-type or Cu 3 Au-type ferromagnetic ordered phase produced by a liquid phase method is selected from FeNi, FePd, FePt, CoPt, CoAu, Ni 3 Fe, FePd 3 , Fe 3 Pt, FePt 3 , CoPt 3 , Ni 3 Pt, CrPt 3 and Ni 3 Mn.