Patent classifications
G11B5/7356
Magnetic recording medium
An object of the present disclosure is to provide a magnetic recording medium excellent in electro-magnetic conversion characteristic and thermal stability. The present disclosure provides a tape-shaped magnetic recording medium including: a substrate; and a magnetic layer provided over the substrate and including a magnetic powder, in which the magnetic layer has an average thickness of equal to or less than 90 nm, the magnetic powder has an average aspect ratio of from 1.0 to 3.0, the magnetic powder has an average particle volume of equal to or less than 2,300 nm.sup.3, a coercive force Hc1 in a vertical direction of the magnetic recording medium is equal to or less than 4,500 Oe, a coercive force Hc2 in a longitudinal direction of the magnetic recording medium and the coercive force Hc1 satisfy a relation of Hc2/Hc1≤0.8, and the ratio Hrp/Hc1 of a residual coercive force Hrp of the magnetic recording medium measured using a pulsed magnetic field and the coercive force Hc1 is equal to or less than 2.0.
MAGNETIC RECORDING MEDIUM, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC RECORDING AND REPRODUCING DEVICE
A magnetic recording medium including a non-magnetic support, and a magnetic layer including a ferromagnetic powder. The ferromagnetic powder is an ε-iron oxide powder, a ratio (Hr (90°)/Hr (0°)) of Hr (90°) to Hr (0°) is 0.50 or less, the Hr (0°) is a residual coercive force obtained by applying a pulse magnetic field having a pulse width of 0.76 ms in an in-plane direction of the magnetic recording medium, and the Hr (90°) is a residual coercive force obtained by making a pulse magnetic field having a pulse width of 0.76 ms be incident from a vertical direction of the magnetic recording medium and applying the pulse magnetic field to the magnetic recording medium.
MAGNETIC TAPE, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC TAPE DEVICE
A magnetic tape in which a tape thickness of the magnetic tape is 5.2 μm or less, and in an environment with a temperature of 23° C. and a relative humidity of 50%, an AlFeSil abrasion value.sub.45° of a surface of the magnetic layer measured at a tilt angle of 45° of an AlFeSil prism is 20 μm to 50 μm, a standard deviation of an AlFeSil abrasion value of the surface of the magnetic layer measured at each of tilt angles of 0°, 15°, 30°, and 45° of the AlFeSil prism is 30 μm or less, and the tilt angle of the AlFeSil prism is an angle formed by a longitudinal direction of the AlFeSil prism and a width direction of the magnetic tape.
MAGNETIC TAPE, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC TAPE DEVICE
A magnetic tape in which a C—H derived C concentration calculated from a C—H peak surface area ratio in C1s spectra obtained by XPS performed on a surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 45 atom % to 65 atom %, and in an environment with a temperature of 23° C. and a relative humidity of 50%, an AlFeSil abrasion value.sub.45° of the surface of the magnetic layer measured at a tilt angle of 45° of an AlFeSil prism is 20 μm to 50 μm, a standard deviation of an AlFeSil abrasion value of the surface of the magnetic layer measured at each of given tilt angles of the AlFeSil prism is 30 μm or less, and the tilt angle of the AlFeSil prism is an angle formed by a longitudinal direction of the AlFeSil prism and a width direction of the magnetic tape.
MAGNETIC TAPE, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC TAPE DEVICE
A magnetic tape in which an edge weave amount of a tape edge on at least one side of the magnetic tape is 1.5 μm or less, and in an environment with a temperature of 23° C. and a relative humidity of 50%, an AlFeSil abrasion value.sub.45° of a surface of the magnetic layer measured at a tilt angle of 45° of an AlFeSil prism is 20 μm to 50 μm, a standard deviation of an AlFeSil abrasion value of the surface of the magnetic layer measured at each of tilt angles of 0°, 15°, 30°, and 45° of the AlFeSil prism is 30 μm or less, and the tilt angle of the AlFeSil prism is an angle formed by a longitudinal direction of the AlFeSil prism and a width direction of the magnetic tape.
MAGNETIC RECORDING MEDIUM, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC RECORDING AND REPRODUCING DEVICE
The magnetic recording medium includes a non-magnetic support; and a magnetic layer containing a ferromagnetic powder, in which the magnetic layer includes an abrasive, the abrasive is a carbide, an average primary particle diameter of the abrasive is 10 nm or more and 100 nm or less, and in an electron microscope image of a surface of the magnetic layer, assuming that a total area occupied by the abrasive is 100%, a ratio of an area occupied by the abrasive present in an aggregated state having a maximum Feret diameter of 0.2 .Math.m or more is 50% or more.
MAGNETIC TAPE
Provided is a magnetic tape in which a thickness of a back coating layer is equal to or smaller than 0.20 μm, a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the back coating layer at a photoelectron take-off angle of 10 degrees, is equal to or greater than 35 atom %, full widths at half maximum of spacing distribution measured by optical interferometry regarding the surface of the back coating layer before and after performing a vacuum heating with respect to the magnetic tape are respectively greater than 0 nm and equal to or smaller than 10.0 nm, and a difference between a spacing measured after performing the vacuum heating and a spacing measured before performing the vacuum heating is greater than 0 nm and equal to or smaller than 8.0 nm.
Magnetic tape cartridge and magnetic tape device having characterized winding deviation occurrence load
The magnetic tape cartridge includes a magnetic tape, and a cartridge reel. In the magnetic tape, a minimum winding deviation occurrence load measured after the magnetic tape is rewound around the cartridge reel by applying a tension of 0.40 N in a longitudinal direction of the magnetic tape is 300 N or less.
MAGNETIC TAPE, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC TAPE DEVICE
Provided are a magnetic tape including a non-magnetic support and a magnetic layer including a ferromagnetic powder, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape. An amount of a fluid lubricant collected by wiping a surface of the magnetic layer by a nonwoven fabric is in a range of 5 to 400 ng/m.sup.2 as a value per unit area of the surface of the magnetic layer.
MAGNETIC TAPE, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC TAPE DEVICE
The magnetic tape has one or more of each of an area A and an area B having different center line average surface roughness Ra measured on a surface of a magnetic layer in a region over a part of the magnetic tape in a longitudinal direction, with a ratio B.sub.Mag/A.sub.Mag of 1.20 to 10.00 and a ratio B.sub.Mag/B.sub.Back of equal to or greater than 2.0 in a case where extraction amounts per unit area of a component selected from the group consisting of fatty acid, fatty acid ester, and fatty acid amide extracted from a magnetic layer side of the area A and the area B are defined as A.sub.Mag and B.sub.Mag respectively, and an extraction amount per unit area of the above component extracted from a back coating layer side of the area B is defined as B.sub.Back.