发明名称 |
Manufacture of acicular ferromagnetic iron particles |
摘要 |
A process for the manufacture of acicular ferromagnetic iron particles by reducing acicular iron(III) oxide hydroxides which consist of pure synthetic lepidocrocite or a mixture of synthetic goethite and at least 70% by weight of synthetic lepidocrocite. The iron(III) oxide hydroxides used carry, on their surface, an alkaline earth metal cation and an anion of a monobasic, dibasic or tribasic aliphatic carboxylic acid of up to 6 carbon atoms or an organic compound containing at least two groups capable of chelating the alkaline earth metal cation, and are produced in such a way that they consist of at least 70 percent by weight of lepidocrocite and have a length-to-width ratio of not less than 15:1. Reduction of such iron(III) oxide hydroxides gives iron particles with pronounced shape anisotropy, which exhibit both good magnetic properties and a narrow field strength distribution.
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申请公布号 |
US4178171(A) |
申请公布日期 |
1979.12.11 |
申请号 |
US19780888508 |
申请日期 |
1978.03.20 |
申请人 |
BASF AG |
发明人 |
BRODT, RUDOLF;JAKUSCH, HELMUT;KOESTER, EBERHARD;OHLINGER, MANFRED;SARNECKI, WILHELM;STECK, WERNER |
分类号 |
G11B5/706;B22F9/22;C09D5/23;C09D7/12;C21B15/00;G11B5/712;G11B5/714;H01F1/06;(IPC1-7):B22F9/00 |
主分类号 |
G11B5/706 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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