Fujifilm Corporation

Eiki Ozawa

Norihito Kasada

Tetsuya Kaneko

Takuto Kurokawa

Atsushi Musha

Toshio Tada

Naoki Sano

Takashi Fujimoto

Masahito Oyanagi

Megumi Nakano

Kentaro Miyamoto

Michitaka Kondo

Provided are 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, and an intensity ratio (Int1/Int2) of diffraction intensities obtained by an X-ray diffraction analysis of the magnetic layer using an In-Plane method after the magnetic layer is pressed at a pressure of 70 atm is 1.0 or more and 6.5 or less, a magnetic tape cartridge and a magnetic recording and reproducing device each including the magnetic recording medium.

Magnetic recording medium having characterized magnetic layer, magnetic tape cartridge, and magnetic recording and reproducing device

A magnetic recording medium including a magnetic layer including a ferromagnetic powder. The ferromagnetic powder is an ε-iron oxide powder, and a ratio of Hr (45°) to Hr (0°) (Hr (45°)/Hr (0°)) is 0.50 or less. The Hr (0°) is a residual coercive force Hr 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 (45°) is a residual coercive force Hr obtained by setting an angle of the magnetic recording medium in the in-plane direction to 0°, setting an angle of the magnetic recording medium in a perpendicular direction to 90°, and making a pulse magnetic field having a pulse width of 0.76 ms be incident from a direction inclined by 45° toward the perpendicular direction from the in-plane direction and applying the pulse magnetic field to the magnetic recording medium.

Magnetic recording medium, magnetic tape cartridge, and magnetic recording and reproducing device

Provided are: a magnetic recording medium including a non-magnetic support and a magnetic layer containing a ferromagnetic powder, in which the ferromagnetic powder is an ε-iron oxide powder, a vertical squareness ratio SQ of the magnetic recording medium is 0.50 or more and 0.95 or less at a measurement temperature of 25° C., and an inclination of SQ obtained from SQ at a measurement temperature of 10° C., SQ at a measurement temperature of 25° C., and SQ at a measurement temperature of 40° C. is −0.0050° C.or more and −0.0003° C.or less; a magnetic tape cartridge including the magnetic recording medium which is a magnetic tape; and a magnetic recording and reproducing device including the magnetic recording medium.

Provided are: a magnetic recording medium including a non-magnetic support and a magnetic layer containing a ferromagnetic powder, in which the ferromagnetic powder is an ε-iron oxide powder, a vertical switching field distribution SFD of the magnetic recording medium is 0.20 or more and 3.00 or less at a measurement temperature of 25° C., and an inclination of SFD obtained from SFD at a measurement temperature of 10° C., SFD at a measurement temperature of 25° C., and SFD at a measurement temperature of 40° C. is 0.003° C.or more and 0.080° C.or less; a magnetic tape cartridge including the magnetic recording medium which is a magnetic tape; and a magnetic recording and reproducing device including the magnetic recording medium.

Magnetic recording medium having characterized vertical SFD, magnetic tape cartridge, and magnetic recording reproducing device

Provided are: a magnetic recording medium including a non-magnetic support and a magnetic layer containing a ferromagnetic powder, in which the ferromagnetic powder is an &#x3b5;-iron oxide powder, a vertical magnetization amount &#x3a6;m per unit area of the magnetic recording medium is 5 G&#xb7;&#x3bc;m or more and 100 G&#xb7;&#x3bc;m or less at a measurement temperature of 25&#xb0; C., and an inclination of &#x3a6;m obtained from &#x3a6;m at a measurement temperature of 10&#xb0; C., &#x3a6;m at a measurement temperature of 25&#xb0; C., and &#x3a6;m at a measurement temperature of 40&#xb0; C. is &#x2212;0.20 G&#xb7;&#x3bc;m/&#xb0; C. or more and &#x2212;0.03 G&#xb7;&#x3bc;m/&#xb0; C. or less; a magnetic tape cartridge including the magnetic recording medium which is a magnetic tape; and a magnetic recording and reproducing device including the magnetic recording medium.

The magnetic tape includes a non-magnetic support and a magnetic layer including ferromagnetic powder, in which the ferromagnetic powder is &#x3b5;-iron oxide powder, and a coefficient of variation of particle size of the &#x3b5;-iron oxide powder in a longitudinal direction of the magnetic layer is 0.50% or more and 5.00% or less.

Magnetic tape having characterized coefficient of variation of e-iron oxide powder particle size, magnetic tape cartridge, and magnetic recording and reproducing apparatus

The magnetic recording medium includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic support, in which a difference (S&#x2212;S) between a spacing Smeasured by optical interferometry regarding a surface of the magnetic layer under a pressing force of 0.5 atm after n-hexane cleaning and a spacing Smeasured by optical interferometry regarding the surface of the magnetic layer under a pressing force of 13.5 atm after n-hexane cleaning is equal to or smaller than 3.0 nm, and a magnetic recording and reproducing device including this magnetic recording medium.

Magnetic recording medium and magnetic recording and reproducing device

An information processing device includes a recording unit that records a plurality of objects including data and metadata related to the data on a magnetic recording medium, and executes, after recording at least one of the objects, processing of recording first set data which is a set of the metadata included in the object. The first set data is the set of the metadata included in the object recorded after recording the first set data that is recorded immediately before. The magnetic recording medium has a magnetic layer containing a ferromagnetic powder and a binding agent on a non-magnetic support. A difference between spacings Sand Smeasured under pressures of 0.5 atm and 13.5 atm by an optical interference method after n-hexane cleaning on a surface of the magnetic layer is equal to or less than 3.0 nm.

Recording device, reading device, recording method, recording program, reading method, reading program, and magnetic tape

The magnetic recording medium includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder, in which an isoelectric point of a surface zeta potential of the magnetic layer after pressing the magnetic layer at a pressure of 70 atm is equal to or less than 3.8.

The magnetic tape includes a non-magnetic support; and a magnetic layer, in which the magnetic layer has a timing-based servo pattern, an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference L&#x2212;Lbetween a value Lof a cumulative distribution function of 99.9% and a value Lof a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the magnetic tape in a longitudinal direction is 180 nm or less, and an absolute value &#x394;N of a difference between a refractive index Nxy of the magnetic layer, measured in an in-plane direction and a refractive index Nz of the magnetic layer, measured in a thickness direction is 0.25 or more and 0.40 or less.

Magnetic tape, magnetic tape cartridge, and magnetic tape apparatus

The magnetic tape includes a non-magnetic support and a magnetic layer including ferromagnetic powder and a binding agent, in which the magnetic layer has a timing-based servo pattern, an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference (L&#x2212;L) between a value Lof a cumulative distribution function of 99.9% and a value Lof a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the magnetic tape in a longitudinal direction is 180 nm or less, and an isoelectric point of a surface zeta potential of the magnetic layer is 3.8 or less.

The magnetic recording medium includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder, in which one or more kinds of component selected from the group consisting of a fatty acid and a fatty acid amide are included in a portion of the magnetic layer side on the non-magnetic support, and a C&#x2014;H derived C concentration calculated from a C&#x2014;H peak surface area ratio in C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on a surface of the magnetic layer at a photoelectron take-off angle of 10 degrees, after pressing the magnetic layer at a pressure of 70 atm is 45 atom % or more.

Magnetic recording medium having characterized magnetic layer and magnetic recording and reproducing device

The magnetic tape includes a non-magnetic support; and a magnetic layer in which the magnetic layer has a timing-based servo pattern, an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference between a value Lof a cumulative distribution function of 99.9% and a value Lof a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the magnetic tape in a longitudinal direction is 180 nm or less, and a difference between a spacing Smeasured on a surface of the magnetic layer by an optical interferometry after methyl-ethyl-ketone cleaning and a spacing Smeasured on the surface of the magnetic layer by an optical interferometry before methyl-ethyl-ketone cleaning is greater than 0 nm and 15.0 nm or less.

The magnetic recording medium includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder, in which an isoelectric point of a surface zeta potential of the magnetic layer after pressing the magnetic layer at a pressure of 70 atm is equal to or greater than 5.5.

Growing community of inventors

Minami-ashigara, Japan

Eiki Ozawa