公开(公告)号：US20240304215A1

公开(公告)日：2024-09-12

申请号：US18585700

申请日：2024-02-23

Applicant: FUJIFILM Corporation

Inventor： Masahide SATO

IPC: G11B5/725 ,  G11B5/84

CPC classification number: G11B5/7253 ,  G11B5/84

Abstract: There is provided a magnetic recording medium in which a contact angle with water, which is measured on a surface of the magnetic layer, is 96 degrees or more, a fluorine concentration F obtained by X-ray photoelectron spectroscopy performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 1.0 at % or more and less than 5.0 at %, and ΔC calculated by Equation ΔC=Cbefore−Cafter is 10.0 at % or more and 30.0 at % or less. The Cbefore is a C—H derived carbon concentration calculated from a C—H peak surface area ratio in C1s spectra obtained by the X-ray photoelectron spectroscopy performed on the surface of the magnetic layer at the photoelectron take-off angle of 10 degrees before a methanol extraction treatment, and the Cafter is a C—H derived carbon concentration after the methanol extraction treatment.

公开(公告)号：US20160293196A1

公开(公告)日：2016-10-06

申请号：US15084828

申请日：2016-03-30

Applicant: FUJIFILM Corporation

Inventor： Masahide SATO

IPC: G11B5/706 ,  G11B5/714 ,  G11B5/127 ,  G11B5/708 ,  G11B5/73

CPC classification number: G11B5/708 ,  G11B5/714 ,  G11B5/733 ,  G11B5/82

Abstract: The magnetic recording medium has a nonmagnetic layer containing nonmagnetic powder and binder on a nonmagnetic support, and a magnetic layer containing ferromagnetic powder and binder on the nonmagnetic layer, wherein a thickness of the nonmagnetic layer ranges from 0.10 to 0.60 μm; and the magnetic layer further contains nonmagnetic filler satisfying equation 1 below and having a Vickers hardness of less than or equal to 122 N/mm2: 1. 150≦D2/D1≦1.300   Equation 1: wherein, in equation 1, D1 is a value, with a unit of μm, obtained from equation 2 below: D   1 = 6 ρ · S , Equation   2 D2 is an average particle size, with a unit of μm, of the nonmagnetic filler, and in equation 2, ρ denotes a density, with a unit of g/cm3, of the nonmagnetic filler and S denotes a specific surface area, with a unit of m2/g, of the nonmagnetic filler.

公开(公告)号：US20150380037A1

公开(公告)日：2015-12-31

申请号：US14754918

申请日：2015-06-30

Applicant: FUJIFILM CORPORATION

Inventor： Yoshinori TAMADA ,  Masahide SATO ,  Kazufumi OMURA

IPC: G11B5/708

CPC classification number: G11B5/708 ,  G11B5/7013

Abstract: An aspect of the present invention relates to a magnetic recording medium, which comprises a nonmagnetic layer comprising nonmagnetic powder and binder on a nonmagnetic support, and a magnetic layer comprising ferromagnetic powder and binder on the nonmagnetic layer, wherein the magnetic layer further comprises carbon black, and a state in which the carbon black is present, as observed in a reflection electron image of a surface of the magnetic layer obtained by a scanning electron microscope, satisfies condition 1 and condition 2 below: condition 1: a number of carbon black particles with a particle size of greater than or equal to 140 nm is greater than or equal to 30 per 1,000 μm2 of area; and condition 2: a number of carbon black particles with a particle size of greater than or equal to 220 nm is less than or equal to 10 per 1,000 μm2 of area.

Abstract translation: 本发明的一个方面涉及一种磁记录介质，其包括在非磁性载体上包含非磁性粉末和粘合剂的非磁性层，以及在非磁性层上包含铁磁粉末和粘合剂的磁性层，其中所述磁性层还包含炭黑 ，并且如通过扫描型电子显微镜获得的磁性层的反射电子图像中观察到的存在炭黑的状态满足以下条件1和条件2：条件1：炭黑粒子的数量 粒径大于或等于140nm的面积大于或等于30; 条件2：粒径大于或等于220nm的数量的炭黑颗粒小于或等于每1,000平方米面积的10。

公开(公告)号：US20140287271A1

公开(公告)日：2014-09-25

申请号：US14222119

申请日：2014-03-21

Applicant: FUJIFILM Corporation

Inventor： Masahide SATO

IPC: G11B5/708 ,  G11B5/70

CPC classification number: G11B5/708 ,  G11B5/7013

Abstract: The magnetic recording medium comprises protrusions on a surface of a magnetic layer such that when protrusions of equal to or more than 8 nm in height as measured by AFM on the surface of the magnetic layer are divided into protrusions A formed of a spherical material and protrusions B formed of a non-spherical material, a value a, obtained by adding three times a standard deviation σ of heights of protrusions A to an average value of the heights of protrusions A, a value b, obtained by adding three times a standard deviation σ of heights of protrusions B to an average value of the heights of protrusions B, and a difference c, obtained by subtracting b from a, are calculated, conditions 13 nm≦a≦25 nm, 13 nm≦b≦25 nm, and 0.0 nm≦c≦10 nm are satisfied.

Abstract translation: 磁记录介质包括在磁性层的表面上的突起，使得当在磁性层的表面上通过AFM测量的高度等于或大于8nm的突起被分成由球形材料形成的突起A和突起 B由非球形材料形成，a值，通过加三次标准偏差＆sgr获得; 突起A的高度相对于突起A的高度的平均值，通过将标准偏差加上三次而获得的值b; 计算突起B的高度与突起B的高度的平均值的平均值以及从a中减去b获得的差值c，条件为13nm＆lt; nlE; a＆nlE; 25nm，13nm＆nlE; b＆nlE; 25nm和0.0 nm＆nlE; c＆nlE; 10nm。

公开(公告)号：US20130130064A1

公开(公告)日：2013-05-23

申请号：US13682207

申请日：2012-11-20

Applicant: Fujifilm Corporation

Inventor： Masahide SATO

IPC: C09D7/12

CPC classification number: C09D7/63 ,  G11B5/7085 ,  H01F1/113 ,  H01F41/16

Abstract: An aspect of the present invention relates to an alumina dispersion, which is employed to manufacture a particulate magnetic recording medium, comprises alumina, a solvent, and a dispersing agent in the form of an aromatic hydrocarbon compound having a phenolic hydroxyl group, and essentially does not comprise ferromagnetic powder.

Abstract translation: 本发明的一个方面涉及用于制造颗粒状磁记录介质的氧化铝分散体，包括氧化铝，溶剂和具有酚羟基的芳族烃化合物形式的分散剂，并且基本上 不含铁磁性粉末。

公开(公告)号：US20130260179A1

公开(公告)日：2013-10-03

申请号：US13838996

申请日：2013-03-15

Applicant: FUJIFILM CORPORATION

Inventor： Norihito KASADA ,  Masahide SATO ,  Isamu WATANABE

IPC: G11B5/708 ,  G11B5/842

CPC classification number: G11B5/7085 ,  G11B5/70 ,  G11B5/7013 ,  G11B5/842

Abstract: An aspect of the present invention relates to a magnetic recording medium, which comprises a nonmagnetic layer containing a nonmagnetic powder and a binder and a magnetic layer containing a ferromagnetic powder and a binder in this order on a nonmagnetic support, wherein the nonmagnetic layer has a thickness of equal to or less than 300 nm; a composite elastic modulus as measured on a surface of the magnetic layer ranges from 6.0 to 8.0 GPa; the magnetic layer comprises an abrasive with a specific surface area by BET method ranging from 14 m2/g to 40 m2/g; and a surface abrasive occupancy on a surface of the magnetic layer ranges from 0.2% to 2%.

Abstract translation: 本发明的一个方面涉及一种磁记录介质，其在非磁性载体上依次包括含有非磁性粉末和粘合剂的非磁性层和含有铁磁粉末和粘合剂的磁性层，其中非磁性层具有 等于或小于300nm的厚度; 在磁性层表面测得的复合弹性模量为6.0-8.0GPa; 磁性层包括通过BET法测量的比表面积为14m 2 / g至40m 2 / g的研磨剂; 在磁性层的表面上的表面磨料占有率为0.2％〜2％。