Process for preparing magnetic iron oxide and magnetic iron oxide
produced thereby
    1.
    发明授权
    Process for preparing magnetic iron oxide and magnetic iron oxide produced thereby 失效
    由此制备磁性氧化铁和磁性氧化铁的方法

    公开(公告)号:US4200680A

    公开(公告)日:1980-04-29

    申请号:US586443

    申请日:1975-06-12

    摘要: A magnetic iron oxide having a large coercive force and an improved squareness ratio prepared by coating the surface of needle-like particles of magnetic iron oxide with a cobalt compound, placing the coated iron oxide particles in a unidirectionally oriented magnetic field thereby orienting the particles in the direction of the magnetic field, and heat-treating the needle-like particles in this state with the application of an external magnetic field, or heat-treating the needle-like particles in a magnetized state.

    摘要翻译: 通过用钴化合物涂覆磁性氧化铁的针状颗粒的表面而制备的具有大的矫顽力和改善的矩形比的磁性氧化铁,将涂覆的氧化铁颗粒置于单向取向的磁场中,从而使颗粒定向 磁场的方向,在这种状态下通过施加外部磁场对针状颗粒进行热处理,或者将针状颗粒热处理为磁化状态。

    Process for stabilization of ferromagnetic material and magnetic
recording member
    2.
    发明授权
    Process for stabilization of ferromagnetic material and magnetic recording member 失效
    强磁性材料和磁记录元件的稳定化工艺

    公开(公告)号:US4015030A

    公开(公告)日:1977-03-29

    申请号:US591681

    申请日:1975-06-30

    CPC分类号: G11B5/70694

    摘要: A process for stabilizing a ferromagnetic material comprising heat-treating a needle-like ferromagnetic material represented by the formula MO.sub.x wherein M is a ferromagnetic metal ion or a ferromagnetic non-metal ion and another metal ion, and x is the degree of oxidation which ranges from 1.36 to 1.47, and containing at least 0.5 atom % Co, at a temperature of at least about 40.degree. C, and a process for stabilizing a magnetic recording member comprising heat-treating a magnetic recording member produced by providing a ferromagnetic recording layer comprising (a) a ferromagnetic material represented by the formula MO.sub.x wherein M and x are the same as defined above, and containing at least 0.5 atom % Co, and (b) a binder, on a support, at a temperature of at least about 40.degree. C.

    摘要翻译: 一种用于稳定铁磁材料的方法,包括热处理由式MOx表示的针状铁磁材料,其中M是铁磁金属离子或铁磁性非金属离子和另一种金属离子,x是氧化程度 1.36至1.47,并且在至少约40℃的温度下含有至少0.5原子%的Co,以及用于稳定磁性记录元件的方法,该方法包括热处理通过提供铁磁性记录层产生的磁性记录元件,所述磁性记录元件包括 (a)由式MOx表示的铁磁材料,其中M和x与上述定义相同,并且在载体上至少包含至少约40的温度下含有至少0.5原子%的Co和(b)粘合剂 DEG C.

    Process for producing cobalt-containing ferromagnetic iron oxide powder
    3.
    发明授权
    Process for producing cobalt-containing ferromagnetic iron oxide powder 失效
    含钴铁磁性氧化铁粉末的生产工艺

    公开(公告)号:US4267207A

    公开(公告)日:1981-05-12

    申请号:US39028

    申请日:1979-05-14

    摘要: A process for producing a cobalt-containing ferromagnetic iron oxide powder suitable for magnetic recording which comprises(a) mixing cobalt ion, ferrous ion and an alkali with an aqueous dispersion of acicular ferromagnetic iron oxide nuclei under non-oxidizing conditions at a temperature of about 50.degree. C. or less;(b) heating the dispersion to a temperature of at least about 60.degree. C. but below the boiling point of the dispersion under non-oxidizing conditions to cause a reaction; and(c) treating the dispersion at a temperature of at least about 60.degree. C. but below the boiling point of the dispersion under the following conditions:(1) initially treating the dispersion under non-oxidizing conditions for about 5 minutes or more;(2) subsequentially treating the dispersion under oxidizing conditions for about 5 minutes or more prior to the termination of the reaction; and(3) a total treating time under non-oxidizing conditions and oxidizing conditions of at least about 30 minutes.

    摘要翻译: 一种适用于磁记录的含钴铁磁性氧化铁粉末的制造方法,其特征在于,包括:(a)在非氧化条件下,将钴离子,亚铁离子和碱与针状铁磁性氧化铁核的水分散体混合, 50℃以下; (b)在非氧化条件下将分散体加热到至少约60℃但低于分散体的沸点以引起反应; 和(c)在以下条件下,在至少约60℃但低于分散体沸点的温度下处理分散体:(1)最初在非氧化条件下处理分散体约5分钟或更长时间; (2)在反应终止之前,在氧化条件下将分散体顺序处理约5分钟或更长时间; 和(3)在非氧化条件和氧化条件下的总处理时间为至少约30分钟。

    Magnetic recording medium and method for magnetic recording and
reproduction
    8.
    发明授权
    Magnetic recording medium and method for magnetic recording and reproduction 失效
    磁记录介质和磁记录和再现方法

    公开(公告)号:US4982302A

    公开(公告)日:1991-01-01

    申请号:US179352

    申请日:1988-04-08

    摘要: A method for magnetic recording and reproduction comprising the steps of: (1) magnetically multiple-recording signals on a magnetic recording medium comprising a support having thereon an upper magnetic recording layer comprising barium ferrite having an increased coercive force at 60.degree. C. or more and a lower magnetic recording layer comprising at least one of chromium dioxide and Co-modified iron oxide, having a decreased coercive force at 60.degree. C. or more, disposed between said upper magnetic recording layer and said support; (2) heating said magnetic recording layers prior to reproduction due to a reproducing head; and (3) reproducing said magnetically recorded signal from said heated magnetic recording medium which is multiple-recorded.

    摘要翻译: 一种用于磁记录和再现的方法,包括以下步骤:(1)磁记录介质上的磁记录信号,该磁记录介质包括一个载体,其上有一个上磁记录层,该磁记录层包括在60℃以上矫顽力增加的钡铁氧体 以及设置在所述上​​部磁记录层和所述支撑体之间的包含二氧化铬和Co改性氧化铁中的至少一种,具有降低的矫顽力在60℃以上的低磁记录层; (2)由于再现头而在再现之前加热所述磁记录层; 和(3)从被记录的多个加热磁记录介质再现所述磁记录信号。

    Process for producing magnetic FE oxide
    9.
    发明授权
    Process for producing magnetic FE oxide 失效
    磁性FE氧化物的制造方法

    公开(公告)号:US4179387A

    公开(公告)日:1979-12-18

    申请号:US862884

    申请日:1977-12-21

    CPC分类号: G11B5/70689 G11B5/70626

    摘要: A magnetic Fe oxide containing Co, and optionally, a divalent metal, in which the oxidation degree indicated by the following formula ranges from about 30% to 80%; ##EQU1## wherein y is the amount of the Co, plus the divalent metal if present, in atomic % contained in the magnetic Fe oxide, and R is the ratio of the divalent Fe ion to the total Fe ions;and a process for producing a magnetic Fe oxide containing Co, and optionally, a divalent metal, and having an oxidizing degree of about 30 to 80%, which comprises dehydrating and reducing goethite containing Co, and optionally, the divalent metal, to obtain magnetic containing Co, and optionally, a divalent metal, and oxidizing gradually the magnetite at a relatively low temperature of lower than about 100.degree. C.

    摘要翻译: 含有Co和任选的二价金属的磁性Fe氧化物,其中由下式表示的氧化度范围为约30%至80%; 其中y是Co的量,加上存在的二价金属,以磁性Fe氧化物中的原子%计,R是二价Fe离子与总Fe离子的比例; 以及含有Co和任选的二价金属,氧化度为约30〜80%的磁性Fe氧化物的制造方法,其包括脱水和还原含有Co的目标物和任选的二价金属,得到磁性 含有Co和任选的二价金属,并在低于约100℃的较低温度下逐渐氧化磁铁矿。