Agglomerated ferromagnetic iron particles
    1.
    发明授权
    Agglomerated ferromagnetic iron particles 失效
    聚集铁磁铁颗粒

    公开(公告)号:US4470844A

    公开(公告)日:1984-09-11

    申请号:US324915

    申请日:1981-11-25

    摘要: Spherical agglomerates of surface-stabilized primary particles substantially consisting of iron, having a BET surface of about 5 to 50 m.sup.2 /g, measured on the agglomerate, in non-pyrophoric form and having a bulk density of about 0.5 to 2.0 kg/l and an agglomerate diameter of about 0.5 to 10 mm are produced by(a) reducing in dry phase particles consisting essentially of iron oxide,(b) intensively dispersing the particles in liquid phase,(c) coating the particles with an inorganic and/or organic coating optionally containing corrosion inhibitors,(d) separating the particles from the liquid phase by evaporating the volatile components with a continuously rotating and simultaneously tumbling movement, and(e) subjecting the resulting granulates to a thermal treatment. The particles are especially useful for the production of magnetic recording media.

    摘要翻译: 基本上由铁组成的表面稳定的一次粒子的球形附聚物,具有约5至50m 2 / g的BET表面积,在附聚物上以非自燃形式测量,堆积密度为约0.5至2.0kg / l, 通过(a)在干相中还原基本上由氧化铁组成的颗粒,(b)将颗粒集中分散在液相中,(c)用无机和/或有机物涂覆颗粒,产生约0.5至10mm的团块直径 任选地含有腐蚀抑制剂的涂层,(d)通过以连续旋转和同时翻转的运动蒸发挥发性组分,和(e)使所得颗粒经受热处理,从而将颗粒与液相分离。 颗粒对于制造磁记录介质特别有用。

    Preparation and use of iron magnetic pigments
    3.
    发明授权
    Preparation and use of iron magnetic pigments 失效
    铁磁性颜料的制备和使用

    公开(公告)号:US4631090A

    公开(公告)日:1986-12-23

    申请号:US740090

    申请日:1985-05-31

    CPC分类号: G11B5/712 H01F1/06 H01F1/065

    摘要: A magnetic pigment consisting essentially of iron, having an X-ray crystallite size with the 110 reflex of from 14 to 22 nm, a coercive force from 55 to 88 kA/m and a switching field distribution of the oriented pigment particles of less than 0.55 is produced by precipitating an iron (II)-salt with a super-stoichiometric quantity of an aqueous alkali metal carbonate solution and oxidizing it to produce .alpha.-FeOOH, .gamma.-Fe.sub.2 O.sub.3, Fe.sub.3 O.sub.4 or betholoid iron oxides, subsequently reducing it to the metal, and providing the iron oxides or oxide hydroxides with an inorganic protection from sintering at the latest during reduction.

    摘要翻译: 一种主要由铁组成的磁性颜料,具有X射线微晶尺寸,其反射率为14至22nm,矫顽力为55至88kA / m,取向颜料颗粒的切换场分布小于0.55 通过用超化学计量的碱金属碳酸盐水溶液沉淀铁(II) - 盐,并将其氧化以产生α-FeO​​OH,γ-Fe 2 O 3,Fe 3 O 4或氧化铝铁氧化物,随后将其还原成金属, 并且在还原期间最终提供具有无机保护的氧化铁或氧化物氢氧化物以免烧结。

    Ferromagnetic metal pigment essentially consisting of iron and a process
for its production
    4.
    发明授权
    Ferromagnetic metal pigment essentially consisting of iron and a process for its production 失效
    基本上由铁组成的铁磁金属颜料及其生产方法

    公开(公告)号:US4290799A

    公开(公告)日:1981-09-22

    申请号:US124399

    申请日:1980-02-25

    CPC分类号: H01F1/065 G11B5/70615

    摘要: A metal powder, suitable for magnetic recording, consisting essentially of iron, the individual particles being acicular and containing on average no more then 5 pores and consisting on average of no more than 2 metal cores is produced by precipitating and oxidizing an aqueous iron-(II)-salt solution to produce finely divided acicular iron-(III)-oxide-hydroxide, stabilizing it as by treatment with cadmium, lead, calcium, magnesium, zinc, aluminum, chromium, tungsten, a phosphorus oxide and/or a boron oxide, converting it into ferromagnetic iron oxide of low pore content, and reducing it to metallic iron with a gaseous reducing agent at about 300.degree. to 600.degree. C.

    摘要翻译: 一种适用于磁记录的金属粉末,主要由铁组成,单个颗粒是针状的并且平均包含不超过5个孔,平均不超过2个金属芯构成,通过沉淀和氧化铁 - ( II)盐溶液以产生细分的针状铁 - (III) - 氧化物氢氧化物,通过用镉,铅,钙,镁,锌,铝,铬,钨,磷氧化物和/或硼处理来稳定化 氧化物,将其转化成低孔含量的铁磁性氧化铁,并在约300℃至600℃下用气态还原剂将其还原成金属铁。