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    Process for producing acicular goethite particles and acicular magnetic iron oxide particles
    62.
    发明授权
    Process for producing acicular goethite particles and acicular magnetic iron oxide particles 失效
    制备针状针铁矿颗粒和针状磁性氧化铁颗粒的方法

    公开(公告)号：US5399278A

    公开(公告)日：1995-03-21

    申请号：US22844

    申请日：1993-02-25

    Applicant: Katsumi Yamashita ,  Tosiharu Harada ,  Haruki Kurokawa ,  Kazuhisa Inaba ,  Hideaki Sadamura ,  Tomohisa Moriya ,  Junichi Kawano

    Inventor： Katsumi Yamashita ,  Tosiharu Harada ,  Haruki Kurokawa ,  Kazuhisa Inaba ,  Hideaki Sadamura ,  Tomohisa Moriya ,  Junichi Kawano

    IPC: C01G49/00 ,  C01G49/06 ,  C01G49/08 ,  G11B5/706 ,  H01F1/11

    CPC classification number: G11B5/70642 ,  B82Y30/00 ,  C01G49/06 ,  C01G49/08 ,  C01P2004/03 ,  C01P2004/10 ,  C01P2004/51 ,  C01P2004/54 ,  C01P2004/62 ,  C01P2004/64 ,  C01P2006/42

    Abstract: Disclosed herein are a process for producing acicular goethite particles comprising the steps of: blowing an oxygen-containing gas into a ferrous salt reaction solution containing colloidal ferrous hydroxide or iron-containing colloidal precipitates which is obtained by reacting an aqueous ferrous salt solution with less than one equivalent of an aqueous alkali hydroxide solution and/or an aqueous alkali carbonate solution based on Fe.sup.2 + in said aqueous ferrous salt solution so as to oxidize said colloidal ferrous hydroxide or iron-containing colloidal precipitates and to produce acicular goethite nucleus particles, adding to the resultant aqueous ferrous salt reaction solution containing said acicular goethite nucleus particles not less than one equivalent of an aqueous alkali carbonate solution based on Fe.sup.2 + in said aqueous ferrous salt reaction solution, and blowing an oxygen-containing gas into the mixed aqueous ferrous salt reaction solution so as to grow said goethite nucleus particles; and a process for producing acicular magnetic iron oxide particles by reducing the acicular goethite particles obtained in the above process to produce acicular magnetite particles, and if necessary, oxidizing the acicular magnetite particles to obtain acicular maghemite particles, and if necessary, modifying the acicular magnetite or maghemite particles with Co or Co and Fe.sup.2 +.

    Abstract translation: 本文公开了一种制备针状针铁矿颗粒的方法，包括以下步骤：将含氧气体吹入含有胶态氢氧化亚铁或含铁胶体沉淀物的亚铁盐反应溶液中，该溶液通过使亚铁盐水溶液与小于 1当量碱金属氢氧化物水溶液和/或基于Fe2 +的碱金属碳酸盐水溶液，在所述含水亚铁盐水溶液中氧化所述胶态氢氧化亚铁或含铁胶体沉淀物，并生成针状针铁矿颗粒，加入到 得到含有所述针状针铁矿颗粒的所述含水亚铁盐反应溶液，其含量不低于所述含水亚铁盐反应溶液中基于Fe2 +的碱金属碳酸盐水溶液的1当量，并将含氧气体吹入混合的含水亚铁盐溶液中， 成长为针铁矿核心部分 粒子 以及通过将上述方法中得到的针状针铁矿粒子还原而制造针状磁性氧化铁粒子的方法，制造针状磁铁矿粒子，根据需要，根据需要氧化针状磁铁矿粒子，得到针状磁赤铁矿粒子，根据需要，对针状磁铁矿 或具有Co或Co和Fe2 +的磁赤铁矿颗粒。

    Acicular ferromagnetic alloy particles and process for producing said particles
    69.
    发明授权
    Acicular ferromagnetic alloy particles and process for producing said particles 失效
    针状铁磁合金颗粒及其制备方法

    公开(公告)号：US4437881A

    公开(公告)日：1984-03-20

    申请号：US513866

    申请日：1983-07-14

    Applicant: Akio Mishima ,  Yoshiro Okuda ,  Tosiharu Harada ,  Akira Mukaizaka ,  Tomoyuki Imai

    Inventor： Akio Mishima ,  Yoshiro Okuda ,  Tosiharu Harada ,  Akira Mukaizaka ,  Tomoyuki Imai

    IPC: G11B5/706 ,  B22F9/22

    CPC classification number: G11B5/70615

    Abstract: Acicular ferromagnetic alloy particles doped with silicon, chromium and nickel and optionally magnesium and a process for producing said particles comprising heating at 300.degree. to 500.degree. C. under reducing atmosphere acicular particles of .alpha.-iron(III) oxide hydroxide doped with silicon, chromium and nickel and optionally magnesium or acicular particles of .alpha.-ferric oxide doped with silicon, chromium and nickel and optionally magnesium obtained by dehydrating the acicular particles of .alpha.-iron(III) oxide hydroxide doped with silicon, chromium and nickel and optionally magnesium are disclosed herein.

    Abstract translation: 掺杂有硅，铬和镍以及任选的镁的针状铁磁性合金颗粒和一种制备所述颗粒的方法，包括在还原性气氛下在300℃至500℃下加热掺杂有硅，铬（III）的α-铁氧化物氢氧化物的针状颗粒 公开了镍和任选的掺有硅，铬和镍的α-氧化铁的镁或针状颗粒和任选的镁，其通过使掺杂有硅，铬和镍以及任选的镁的α-铁（III）氧化物氢氧化物的针状颗粒脱水获得， 这里。

    Method of producing a powder of cobalt-containing needle-like shaped gamma-ferric oxide particles as magnetic recording material
    70.
    发明授权
    Method of producing a powder of cobalt-containing needle-like shaped gamma-ferric oxide particles as magnetic recording material 失效
    含有类似针状形状的游离氧化锰颗粒作为磁记录材料的生产方法

    公开(公告)号：US3720618A

    公开(公告)日：1973-03-13

    申请号：US3720618D

    申请日：1971-02-25

    Applicant: TODA KOGYO CORP

    Inventor： TODA H ,  SHIMIZU S ,  IHARA H

    IPC: C01G49/06 ,  G11B5/706 ,  C04B35/00

    CPC classification number: B82Y30/00 ,  C01G49/06 ,  C01P2004/03 ,  C01P2004/10 ,  C01P2004/54 ,  C01P2004/62 ,  C01P2004/64 ,  C01P2006/12 ,  C01P2006/42 ,  G11B5/70673 ,  Y10S264/58

    Abstract: Procedure is described for producing a powder of cobaltcontaining, needle-like shaped gamma-ferric oxide, gamma -Fe2O3 particles useful for magnetic recording and the making of magnetic tape, magnetic sheet and magnetic disk with the powder which has high coercive force, high remanence and good dispersibility, uniform chemical composition, the cobalt uniformly dispersed on each particle, no twin particle structure, a particle length of 0.2-0.5 micron, a specific surface area of 15-25 m2/g and a content of anion such as SO42 less than 0.1 percent. Alkali is added to a mixture of a ferrous salt solution and a cobalt salt solution until the pH exceeds 11, an oxidizing gas of constant oxygen partial pressure is blown into the solution as uniformly fine air bubbles, also causing agitation while maintaining the solution at 30*-50*C, whereupon alpha-Fe2O3 hydrate particles precipitate with the cobalt ions in solid solution, and by washing, dehydrating, reducing and oxidizing conversion into the desired gamma -Fe2O3 particles results.

    Abstract translation: 描述了制备含钴针状γ-氧化铁粉末，用于磁记录的γ-Fe2O3颗粒和制备具有高矫顽力的粉末的磁带，磁性片和磁盘的粉末的方法， 高残留性和良好的分散性，均匀的化学成分，钴均匀分散在每个颗粒上，没有双颗粒结构，颗粒长度为0.2-0.5微米，比表面积为15-25 m2 / g，阴离子含量如 SO42 < - >小于0.1％。 将碱加入到亚铁盐溶液和钴盐溶液的混合物中，直到pH超过11，将氧分压恒定的氧气气体均匀地吹入溶液中，同时在使溶液保持在30℃的同时引起搅拌 ℃-50℃，此时α-Fe 2 O 3水合物颗粒与固溶体中的钴离子一起沉淀，并通过洗涤，脱水，还原和氧化转化成所需的γ-Fe 2 O 3颗粒。

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