Sony Corporation

Sony Group Corporation

Mitsubishi Denki Kabushiki Kaisha

Bayer Aktiengesellschaft

Renesas Technology Corp.

Noboru Sekiguchi

Minoru Yamaga

Tomoe Ozaki

Junichi Tachibana

Takashi Aizawa

Tetsuo Endo

Ryoichi Hiratsuka

Tooru Sato

Teruo Sai

Hikaru Terui

Mitsuo Kimoto

Yuuko Kamoshita

Kazuyoshi Maekawa

Koji Suzuki

Kazuhiro Abe

Katsunori Maeshima

Yoichi Kanemaki

Kimio Hagi

Tomoo Fukuda

Kazuya Hashimoto

Kazuo Murakami

Jota Ito

Futoshi Sasaki

Minoru Shimada

Akiko Watanabe

Yasuhiro Kanda

Toshio Toyama

Syunji Aoki

Fumio Matsumoto

Takanori Arai

Hisashi Naoshima

Hiroto Atagi

Tadatoshi Kitao

Kazuhisa Mochida

Toshio Hayami

Katsumi Togasaki

Katsumi Morita

Yusuke Masutani

Hiroji Kameda

Akihiro Koga

Mitsuo Inoue

Tetsuya Yonemoto

Kenji Ishihara

A magnetic recording medium sequentially includes a base, an underlayer, and a magnetic layer. The magnetic layer includes magnetic particles, conductive first particles, and second particles having a Mohs hardness of 7.0 or more. The magnetic layer has a concavoconvex shape on a magnetic surface, and the concavoconvex shape includes a first protrusion including the first particles and a second protrusion including the second particles. A ratio H1/H2 of an average height H1 of the first protrusion and an average height H2 of the second protrusion satisfies H1/H2≤2.3, a height range ΔH obtained from statistical information on a height of the concavoconvex shape satisfies 3.00 nm≤ΔH≤6.00 nm, and a gradient range ΔA obtained from statistical information on a gradient of the concavoconvex shape satisfies 4.00 degrees≤ΔA≤9.00 degrees.

Magnetic recording medium and cartridge

Provided is a magnetic recording medium capable of curbing deterioration in electromagnetic conversion characteristics. A magnetic recording medium with a tape shape includes a substrate that contains polyesters, an underlayer that is provided on the substrate, and a magnetic layer that is provided on the underlayer and contains a magnetic powder. The magnetic recording medium contains a lubricant. An average value of arithmetic average roughnesses Ra of a surface of the magnetic layer is 1.3 nm or less. In a case where an average value of peak half widths of a spacing increase region generated on an entrance side of a glass pseudo head which the magnetic recording medium enters when the magnetic recording medium is slid over the glass pseudo head is set as a spacing index SRL and an average value of peak half widths of a spacing increase region generated in the vicinity of an edge of the magnetic recording medium in a width direction when the magnetic recording medium is slid over the glass pseudo head is set as a spacing index SRT, the spacing index SRL is 35 μm or less and the spacing index SRT is 68 μm or less.

A magnetic recording medium is a magnetic recording medium having a tape shape and includes a substrate, an underlayer provided on the substrate, and a magnetic layer provided on the underlayer. The magnetic layer has a surface having an uneven shape, a height range ΔH obtained from statistical information of a height of the uneven shape is in a range of 4.00 nm≤ΔH≤10.00 nm, and a gradient range ΔA obtained from statistical information of a gradient of the uneven shape is in a range of 2.50 degrees≤ΔA.

A magnetic recording medium is a tape-shaped magnetic recording medium, including: a substrate; an underlayer provided on the substrate; and a magnetic layer provided on the underlayer. The substrate contains polyester, each of the underlayer and the magnetic layer contains a lubricant, the magnetic layer has a surface on which a large number of holes is provided, the arithmetic average roughness Ra of the surface is 2.5 nm or less, a BET specific surface area of the entire magnetic recording medium measured in a state where the magnetic recording medium has been washed and dried is 3.5 m/g or more and 7.0 m/g or less, a squareness ratio of the magnetic layer in a vertical direction is 65% or more, an average thickness of the magnetic layer is 80 nm or less, an average thickness of the magnetic recording medium is 5.6 μm or less, and a servo pattern is recorded on the magnetic layer and a statistical value σindicating a non-linearity of the servo pattern is 24 nm or less.

Magnetic recording medium

[Solving Means] A magnetic recording medium according to an embodiment of the present technology is a tape-shaped magnetic recording medium, including: a magnetic layer including a servo band, a servo signal being recorded on the servo band. An index expressed by Sq×Fact.(p−p)/F0(p−p) is 0.42 or more, Sq being a squareness ratio of the magnetic layer in a perpendicular direction, F0(p−p) being a peak-to-peak value of a first magnetic force gradient strength observed by a magnetic force microscope when a servo signal is saturation-recorded on the magnetic layer, Fact.(p−p) being a peak-to-peak value of a second magnetic force gradient strength for the servo signal recorded on the servo band observed by the magnetic force microscope.

Magnetic recording medium and servo signal recording device

A magnetic recording medium is a magnetic recording medium having a tape shape and includes a substrate, an underlayer provided on the substrate, and a magnetic layer provided on the underlayer. The magnetic layer has a surface having an uneven shape, a height range ΔH obtained from statistical information of a height of the uneven shape is in a range of 4.00 nm≤ΔH≤10.00 nm, and a gradient range ΔA obtained from statistical information of a gradient of the uneven shape is in a range of 2.50 degrees ≤ΔA.

It is an object of the present technology to provide a magnetic recording medium that has a small total thickness and achieves excellent travelling stability. The present technology provides a tape-shaped magnetic recording medium including a magnetic layer, an underlayer, a base layer, and a back layer, in which a servo pattern is recorded in the magnetic layer, a statistical value &#x3c3;indicating non-linearity of a servo band and being obtained from a reproduction waveform of a servo signal of the servo pattern is 24 nm or less, the base layer contains polyester as a main component, an average thickness tof the magnetic recording medium is 5.6 &#x3bc;m or less, the magnetic recording medium contains a lubricant, pores are formed in the magnetic recording medium, and an average diameter of the pores of the magnetic recording medium that is measured in a state where the lubricant has been removed from the magnetic recording medium and the magnetic recording medium has been dried, is 6 nm or more and 11 nm or less.

A magnetic recording medium is a tape-shaped magnetic recording medium, including: a substrate; an underlayer provided on the substrate; and a magnetic layer provided on the underlayer. The substrate contains polyester, each of the underlayer and the magnetic layer contains a lubricant, the magnetic layer has a surface on which a large number of holes is provided, the arithmetic average roughness Ra of the surface is 2.5 nm or less, a BET specific surface area of the entire magnetic recording medium measured in a state where the magnetic recording medium has been washed and dried is 3.5 m/g or more and 7.0 m/g or less, a squareness ratio of the magnetic layer in a vertical direction is 65% or more, an average thickness of the magnetic layer is 80 nm or less, an average thickness of the magnetic recording medium is 5.6 &#x3bc;m or less, and a servo pattern is recorded on the magnetic layer and a statistical value &#x3b4;indicating a non-linearity of the servo pattern is 24 nm or less.

A magnetic recording medium is provided and includes a magnetic layer, a non-magnetic layer, a base layer and a back layer, wherein an average thickness tof the magnetic recording medium is t&#x2264;5.3 a dimensional change amount &#x394;w in a width direction with respect to a change in tension in a longitudinal direction is 700 ppm/N&#x2264;&#x394;w, a thickness of the non-magnetic layer is 2.0 &#x3bc;m or less, a squareness ratio measured in a vertical direction of the magnetic recording medium is 65% or more, and the magnetic layer includes a magnetic powder.

A magnetic recording medium includes a flexible and elongated substrate, a soft magnetic layer having an average thickness of 10 nm or more to 50 nm or less, and a recording layer. The soft magnetic layer is disposed between the substrate and the recording layer, and a difference in Young's modulus between the magnetic recording medium and the substrate in a longitudinal direction of the substrate is 2.4 GPa or more.

A magnetic recording medium includes a layer structure including a magnetic layer, a base layer, and a back layer in this order, in which an average thickness tis t&#x2264;5.5 &#x3bc;m, a dimensional variation &#x394;w in a width direction to tension change in a longitudinal direction is 660 ppm/N&#x2264;&#x394;w, and a surface roughness Rof the base layer on a side of the back layer is 4.2 nm&#x2264;R&#x2264;8.5 nm.

Magnetic recording medium having a controlled dimensional variation

A magnetic recording medium is a magnetic recording medium having a tape-like shape and includes a base substrate and a magnetic layer provided on the base substrate. A plurality of data tracks can be formed in the magnetic layer, a width of a data track is 2900 nm or less, and in a case of defining, as wand w, a maximum value and a minimum value respectively out of average values of a width of the magnetic recording medium measured under four kinds of environment in which temperature and relative humidity are set to (10&#xb0; C., 10%), (10&#xb0; C., 80%), (29&#xb0; C., 80%), and (45&#xb0; C., 10%), wand wsatisfy a relation of (w&#x2212;w)/w&#x2264;400 [ppm].

Magnetic recording medium having controlled dimensional characteristics

A tape-like magnetic recording medium includes a reinforced substrate, and a recording layer arranged on the reinforced substrate, and the reinforced substrate includes a substrate that has a first face and a second face opposed to each other, and has an average thickness of 4 &#x3bc;m or smaller, and a metal layer that contains cobalt, arranged on the first face, the reinforced substrate by itself causing thereon a depth of indentation of 0.25 &#x3bc;m or shallower, when a 0.7-mm-diameter hard sphere is impressed against the second face under 5.0 gf load for 10 seconds.

Magnetic recording medium having reinforced substrate

There is provided a magnetic recording medium including a base; a seed layer; a foundation layer; and a recording layer, the seed layer being disposed between the base and the foundation layer, having an amorphous state, including an alloy containing Ti, Cr and O, a percentage of Ti being 30 atomic % to 100 atomic % based on a total amount of Ti and Cr contained in the seed layer, and a percentage of O being 15 atomic % or less based on a total amount of Ti, Cr and O contained in the seed layer. Also, a production method thereof is provided.

Magnetic recording medium and method of producing the same

In a magnetic recording medium, an average thickness tis t&#x2264;5.5 &#x3bc;m, a dimensional variation &#x394;w in a width direction to tension change in a longitudinal direction is 650 ppm/N&#x2264;&#x394;w, and a rate of shrinkage in the longitudinal direction is 0.08% or less.

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Miyagi, Japan

Noboru Sekiguchi