Non-magnetic undercoat layer for magnetic recording medium, magnetic
recording medium and non-magnetic particles
    2.
    发明授权
    Non-magnetic undercoat layer for magnetic recording medium, magnetic recording medium and non-magnetic particles 失效
    用于磁记录介质的非磁性底涂层,磁记录介质和非磁性颗粒

    公开(公告)号:US5604015A

    公开(公告)日:1997-02-18

    申请号:US240512

    申请日:1994-05-10

    摘要: The disclosure describes a non-magnetic undercoating layer for a magnetic recording medium, coated on the surface of a non-magnetic substrate comprising:non-magnetic particles selected from the group consisting of particles (1) and (2):(1) coated acicular or spindle-shaped .alpha.-Fe.sub.2 O.sub.3 particles which are produced by adhering not less than 0.01 to 20 wt % (calculated as Al, SiO.sub.2 or Al and SiO.sub.2, and based on acicular or spindle-shaped .alpha.-Fe.sub.2 O.sub.3 particles as a core material) of an oxide or a hydroxide containing Al, Si or both Al and Si to the surfaces of acicular or spindle-shaped .alpha.-Fe.sub.2 O.sub.3 particles as a core material, and have a molecular weight-dependent parameter .alpha. represented by the following formula of not less than 0.5:As=K.sub.1 .multidot.M.sup..alpha.wherein M represents the number-average molecular weight of a binder resin, As represents the saturation adsorption of said binder resin, and K.sub.1 represents a constant used for measuring As and dependent on the binder resin and a solvent,(2) BaO.4.5Fe.sub.2 O.sub.3 particles having an average particle diameter of not more than 0.1 .mu.m; anda binder resin.

    摘要翻译: 本发明描述了一种涂覆在非磁性基材表面上的用于磁记录介质的非磁性底涂层,包括:选自颗粒(1)和(2)的非磁性颗粒:(1)涂覆 通过粘附不小于0.01至20重量%(以Al,SiO 2或Al和SiO 2计算,并以针状或纺锤形α-Fe2O3颗粒为核心材料)制备的针状或纺锤状α-Fe2O3颗粒, 含有Al,Si或Al和Si的氧化物或氢氧化物作为核心材料的针状或纺锤形α-Fe2O3颗粒的表面,并且具有不低于下列公式的分子量依赖参数α 比0.5:As =K1xMα其中M表示粘合剂树脂的数均分子量,As表示所述粘合剂树脂的饱和吸附,K1表示用于测量As的常数,并且取决于粘合剂树脂和溶剂, ( 2)平均粒径不大于0.1μm的BaO.4.5Fe2O3颗粒; 和粘合剂树脂。

    Non-magnetic undercoating layer for magnetic recording medium, magnetic
recording medium and non-magnetic particles
    3.
    发明授权
    Non-magnetic undercoating layer for magnetic recording medium, magnetic recording medium and non-magnetic particles 失效
    用于磁记录介质的非磁性底涂层,磁记录介质和非磁性颗粒

    公开(公告)号:US5830557A

    公开(公告)日:1998-11-03

    申请号:US392199

    申请日:1995-02-22

    摘要: The disclosure describes a non-magnetic undercoating layer for a magnetic recording medium, coated on the surface of a non-magnetic substrate comprising: non-magnetic particles selected from the group consisting of particles (1) and (2): (1) coated acicular or spindle-shaped .alpha.-Fe.sub.2 O.sub.3 particles which are produced by adhering not less than 0.01 to 20 wt % (calculated as Al, SiO.sub.2 or Al and SiO.sub.2, and based on acicular or spindle-shaped .alpha.-Fe.sub.2 O.sub.3 particles as a core material) of an oxide or a hydroxide containing Al, Si or both Al and Si to the surfaces of acicular or spindle-shaped .alpha.-Fe.sub.2 O.sub.3 particles as a core material, and have a molecular weight-dependent parameter .alpha. represented by the following formula of not less than 0.5: As=K.sub.1 .multidot.M.sup..alpha. wherein M represents the number-average molecular weight of a binder resin, As represents the saturation adsorption of said binder resin, and K.sub.1 represents a constant used for measuring As and dependent on the binder resin and a solvent, (2) BaO.multidot.4.5Fe.sub.2 O.sub.3 particles having an average particle diameter of not more than 0.1 .mu.m; and a binder resin.

    摘要翻译: 本发明描述了一种涂覆在非磁性基材表面上的用于磁记录介质的非磁性底涂层,包括:选自颗粒(1)和(2)的非磁性颗粒:(1)涂覆 通过粘附不小于0.01至20重量%(以Al,SiO 2或Al和SiO 2计算,并以针状或纺锤形α-Fe2O3颗粒为核心材料)制备的针状或纺锤状α-Fe2O3颗粒, 含有Al,Si或Al和Si的氧化物或氢氧化物作为核心材料的针状或纺锤形α-Fe2O3颗粒的表面,并且具有不低于下列公式的分子量依赖参数α 比0.5:As =K1xMα其中M表示粘合剂树脂的数均分子量,As表示所述粘合剂树脂的饱和吸附,K1表示用于测量As的常数,并且取决于粘合剂树脂和溶剂, ( 2)平均粒径不大于0.1μm的BaO x 4.5 Fe 2 O 3粒子; 和粘合剂树脂。

    Non-magnetic coated particles having a defined parameter .alpha. of not
less than 0.5
    5.
    发明授权
    Non-magnetic coated particles having a defined parameter .alpha. of not less than 0.5 失效
    具有不小于0.5的限定参数α的非磁性涂覆颗粒

    公开(公告)号:US5882795A

    公开(公告)日:1999-03-16

    申请号:US392259

    申请日:1995-02-22

    IPC分类号: G11B5/733 G11B5/738 B32B1/00

    摘要: The disclosure describes a non-magnetic undercoating layer for a magnetic recording medium, coated on the surface of a non-magnetic substrate comprising:non-magnetic particles selected from the group consisting of particles (1) and (2):(1) coated acicular or spindle-shaped .alpha.-Fe.sub.2 O.sub.3 particles which are produced by adhering not less than 0.01 to 20 wt % (calculated as Al, SiO.sub.2 or Al and SiO.sub.2, and based on acicular or spindle-shaped .alpha.-Fe.sub.2 O.sub.3 particles as a core material) of an oxide or a hydroxide containing Al, Si or both Al and Si to the surfaces of acicular or spindle-shaped .alpha.-Fe.sub.2 O.sub.3 particles as a core material, and have a molecular weight-dependent parameter .alpha. represented by the following formula of not less than 0.5:As=K.sub.1 .multidot.M.sup..alpha. wherein M represents the number-average molecular weight of a binder resin, As represents the saturation adsorption of said binder resin, and K.sub.1 represents a constant used for measuring As and dependent on the binder resin and a solvent,(2) BaO.4.5Fe.sub.2 O.sub.3 particles having an average particle diameter of not more than 0.1 .mu.m; anda binder resin.

    摘要翻译: 本发明描述了一种涂覆在非磁性基材表面上的用于磁记录介质的非磁性底涂层,包括:选自颗粒(1)和(2)的非磁性颗粒:(1)涂覆 通过粘附不小于0.01至20重量%(以Al,SiO 2或Al和SiO 2计算,并以针状或纺锤形α-Fe2O3颗粒为核心材料)制备的针状或纺锤状α-Fe2O3颗粒, 含有Al,Si或Al和Si的氧化物或氢氧化物作为核心材料的针状或纺锤形α-Fe2O3颗粒的表面,并且具有不低于下列公式的分子量依赖参数α 比0.5:As =K1xMα其中M表示粘合剂树脂的数均分子量,As表示所述粘合剂树脂的饱和吸附,K1表示用于测量As的常数,并且取决于粘合剂树脂和溶剂, ( 2)平均粒径不大于0.1μm的BaO.4.5Fe2O3颗粒; 和粘合剂树脂。

    Magnetic recording medium and process for producing the same
    6.
    发明授权
    Magnetic recording medium and process for producing the same 失效
    磁记录介质及其制造方法

    公开(公告)号:US06821618B2

    公开(公告)日:2004-11-23

    申请号:US10185728

    申请日:2002-07-01

    IPC分类号: C23C1408

    摘要: A magnetic recording medium exhibiting a high coercive force and excellent squareness having a substrate, an underlayer formed on the substrate, and a spinel-type iron oxide thin film with maghemite as a main component formed on the underlayer. The spinel-type iron oxide thin film has a thickness (t) of 5 to 50 nm, is constituted by grains having an average grain size (D) of 5 to 30 nm, standard deviation of sizes of grain of not more than 4 nm and a ratio (D/t) of the average grain size (D) to the thickness (t) of less than 1.0, exhibits a coercive force of not less than 159 kA/m (2,000 Oe) and a coercive squareness ratio S* of not less than 0.5:1 in a longitudinal recording medium or a squareness ratio not less than 0.75:1 in a perpendicular recording medium.

    摘要翻译: 具有高矫顽力和具有基底的优良矩形性的磁记录介质,在基底上形成的底层和在底层上形成有以磁赤铁矿为主要成分的尖晶石型氧化铁薄膜。 尖晶石型氧化铁薄膜的厚度(t)为5〜50nm,由平均粒径(D)为5〜30nm的晶粒构成,粒径不超过4nm的标准偏差 平均粒径(D)与厚度(t)的比(D / t)小于1.0时,矫顽力为159kA / m 2(2000Oe),矫顽截面比S * 在纵向记录介质中不小于0.5:1,或垂直记录介质中不小于0.75:1的矩形比。

    Magnetic metal particles containing iron as main component, process for producing the same and magnetic recording medium using the same
    8.
    发明授权
    Magnetic metal particles containing iron as main component, process for producing the same and magnetic recording medium using the same 失效
    含有铁作为主要成分的磁性金属颗粒,其制造方法和使用其的磁性记录介质

    公开(公告)号:US07172642B2

    公开(公告)日:2007-02-06

    申请号:US10305353

    申请日:2002-11-27

    IPC分类号: B22F1/00 B22F9/20 H01F1/16

    摘要: Magnetic metal particles containing iron as a main component, comprising cobalt in an amount of usually 20 to 50 atm %, calculated as Co, based on whole Fe, aluminum in an amount of usually 3 to 15 atm %, calculated as Al, based on whole Fe and a rare earth element in an amount of usually 3 to 20 atm %, calculated as rare earth element, based on whole Fe, and having an average major axis diameter of usually 0.02 to 0.065 μm, preferably from 0.02 to less than 0.05 μm, a coercive force of usually 159.2 to 222.9 kA/m (2,000 to 2,800 Oe), a soluble Na content of usually not more than 30 ppm, a soluble Ca content of usually not more than 100 ppm, and an oxidation stability Δσs of usually not more than 10%.

    摘要翻译: 以铁为主要成分的磁性金属颗粒,其含量通常为20〜50atm%,以Co为基准,以Fe为基准,以Al计,通常为3〜15atm% 整个Fe和稀土元素,通常为3〜20atm%,以稀土元素计,以Fe为基准,平均长轴直径通常为0.02〜0.065μm,优选为0.02〜0.05wt% 妈妈,通常为159.2〜222.9kA / m(2,000〜2,800Oe)的矫顽力,通常不超过30ppm的可溶性Na含量,通常不大于100ppm的可溶性Ca含量,以及氧化稳定性Deltasigmas 通常不超过10%。

    Perpendicular magnetic recording medium
    9.
    发明授权
    Perpendicular magnetic recording medium 失效
    垂直磁记录介质

    公开(公告)号:US06916530B2

    公开(公告)日:2005-07-12

    申请号:US10255075

    申请日:2002-09-26

    摘要: A perpendicular magnetic recording medium, comprises a substrate; a soft-magnetic layer formed on the substrate; an NaCl-type oxide layer for orientation control formed on the soft-magnetic layer, having a thickness of from more than 0 to less than 10 nm; and a magnetic recording layer formed on the NaCl-type oxide layer for orientation control, comprising a maghemite thin film. Such a perpendicular magnetic recording medium is capable of showing excellent magnetic properties, a high recording resolution and improved surface properties.

    摘要翻译: 垂直磁记录介质,包括基板; 形成在所述基板上的软磁性层; 用于定向控制的NaCl型氧化物层形成在软磁层上,其厚度大于0至小于10nm; 以及形成在用于取向控制的NaCl型氧化物层上的磁记录层,包括磁赤铁矿薄膜。 这样的垂直磁记录介质能够显示优异的磁性能,高记录分辨率和改进的表面性能。

    Spindle-shaped goethite particles, spindle-shaped hematite particles and magnetic spindle-shaped metal particles containing iron as main component
    10.
    发明授权
    Spindle-shaped goethite particles, spindle-shaped hematite particles and magnetic spindle-shaped metal particles containing iron as main component 失效
    主轴形针铁矿颗粒,纺锤状赤铁矿颗粒和含有铁作为主要成分的磁性纺锤状金属颗粒

    公开(公告)号:US06309479B1

    公开(公告)日:2001-10-30

    申请号:US09260481

    申请日:1999-03-02

    IPC分类号: H01F1053

    摘要: Spindle-shaped metal particles and a process for producing magnetic spindle-shaped metal particle containing iron as a main component, which contains cobalt of 8 to 45 atm % calculated as Co, aluminum of 5 to 20 atm %, calculated as Al, and a rare earth element of 1 to 15 atm %, calculated as rare earth element, wherein the particles have an average major axial diameter of 0.05 to 0.15 &mgr;m, an average minor axial diameter of 0.010 to 0.022 &mgr;m, an aspect ratio of 4:1 to 8:1, a particle size distribution of not more than 0.20, and an X-ray crystallite size D110 of 12.0 to 17.0 nm. The spindle-shaped metal particles have a high coercive force, an excellent particle coercive force distribution, a large saturation magnetization and an excellent oxidation stability, and are excellent in a squareness (Br/Bm) of the sheet due to a good dispersibility in a binder resin.

    摘要翻译: 主轴形金属颗粒和以铁计为主要成分的磁性纺锤形金属颗粒的制造方法,其以Co计为8〜45atm%的钴,以Al计为5〜20atm%的铝, 稀土元素为1〜15atm%,以稀土元素计,其中平均主轴径为0.05〜0.15μm,平均小轴径为0.010〜0.022μm,纵横比为4:1〜 8:1,粒径分布不大于0.20,X射线晶粒尺寸D110为12.0〜17.0nm。 纺锤形金属颗粒具有高的矫顽力,优异的颗粒矫顽力分布,大的饱和磁化强度和优异的氧化稳定性,并且由于分散性良好,片材的矩形度(Br / Bm)优异 粘合剂树脂。