Manufacture of magnetic recording media having a wear-resistant surface
    8.
    发明授权
    Manufacture of magnetic recording media having a wear-resistant surface 失效
    具有耐磨表面的磁记录介质的制造

    公开(公告)号:US4272563A

    公开(公告)日:1981-06-09

    申请号:US765159

    申请日:1977-02-03

    CPC分类号: G11B5/72 G11B5/84

    摘要: A process for the manufacture of wear-resistant magnetic recording media comprising a dimensionally stable base, a thin ferromagnetic metal layer, containing cobalt and/or nickel, firmly bonded thereto and a thin protective layer applied thereon. The protective layer is produced by treating the recording medium in a liquid basic medium, containing gaseous oxygen, for from 1 to 60 minutes at from 5.degree. to 70.degree. C., washing and drying the treated recording medium and then heating it in air at from 170.degree. to 300.degree. C. This method offers a particularly simple way of providing the ferromagnetic layer of the recording medium with a thin but uniform, mechanically stable and wear-resistant protective layer.

    摘要翻译: 一种用于制造耐磨磁记录介质的方法,其包括尺寸稳定的基底,与包含钴和/或镍的薄的铁磁金属层,其牢固地结合到其上并施加有薄的保护层。 保护层通过在含有气态氧的液体碱性介质中在5至70℃下处理记录介质1至60分钟来制备,洗涤和干燥经处理的记录介质,然后在空气中加热 从170℃到300℃。该方法提供了一种特别简单的方式来提供记录介质的铁磁层,其具有薄而均匀的机械稳定且耐磨的保护层。

    Manufacture of acicular cobalt-modified magnetic iron oxide
    9.
    发明授权
    Manufacture of acicular cobalt-modified magnetic iron oxide 失效
    针状钴改性磁性氧化铁的制造

    公开(公告)号:US4188302A

    公开(公告)日:1980-02-12

    申请号:US872262

    申请日:1978-01-25

    摘要: A process for the manufacture of an acicular magnetic iron oxide containing from 0.5 to 10 percent by weight of cobalt and up to 24 percent by weight of divalent iron, each based on the amount of iron(III) oxide, wherein an aqueous suspension of gamma-iron(III) oxide, containing cobalt(II) and iron(II) ions, the suspension having a hydroxyl ion concentration of more than 3.6.times.10.sup.-6 moles/liter, is heated at from 50.degree. to 100.degree. C. for at least 15 minutes, and the resulting precipitate is filtered off, washed until neutral, dried at below 100.degree. C. and thereafter heated at from 100.degree. to 200.degree. C.The products thus obtained give, even when their cobalt content is low, a very high coercive force, while the effect of temperature on the coercive force and residual induction is very slight.

    摘要翻译: 一种用于制造针状磁性氧化铁的方法,其含有0.5至10重量%的钴和至多24重量%的二价铁,每个基于氧化铁(III)的量,其中γ 氧化铁(III),含有钴(II)和铁(II)离子,羟基离子浓度大于3.6×10 -6摩尔/升的悬浮液在50℃至100℃下加热至 至少15分钟,滤出所得沉淀物,洗涤至中性,在100℃以下干燥,然后在100〜200℃下加热。由此得到的产物即使在钴含量低的情况下也能得到 矫顽力非常高,而温度对矫顽力和残余感应的影响非常小。