公开(公告)号：US5609789A

公开(公告)日：1997-03-11

申请号：US635540

申请日：1996-04-22

申请人： Kiyoshi Asano ,  Arata Koyama ,  Nobusuke Takumi ,  Shigeru Takatori ,  Kouichi Tamura ,  Tokuo Suita

发明人： Kiyoshi Asano ,  Arata Koyama ,  Nobusuke Takumi ,  Shigeru Takatori ,  Kouichi Tamura ,  Tokuo Suita

IPC分类号： C01G49/06 ,  G11B5/706 ,  C04B35/26

CPC分类号： C01G49/06 ,  G11B5/70673 ,  G11B5/70684 ,  C01P2006/12 ,  C01P2006/42 ,  Y10T428/2991

摘要： Cobalt-containing magnetic iron oxide particles extremely suitable for magnetic recording mediums, especially for image recording mediums and a process for producing the same from the precursor, .gamma.-FeOOH which is advantageous in industry are disclosed. Cobalt-containing magnetic iron oxide particles satisfying the following equations (1), (2) and (3):20.ltoreq.SSA.ltoreq.50 (1)-16.70.ltoreq.log [V].ltoreq.-3.05 log [SSA]-11.35 (2)0.10.ltoreq.Fe.sup.2+ /total Fe.ltoreq.0.30 (3)where SSA is a BET specific surface area (m.sup.2 /g), and V is a magnetic switching unit (cm.sup.3), can be produced by producing iron oxide particles having a concentration of Fe.sup.2+ of 0.10 to 0.36 as expressed by Fe.sup.2+ /total Fe from the precursor, .gamma.-FeOOH, and coating a cobalt compound or a combination of a cobalt compound and other metal compounds on the surfaces of the iron oxide particles.

摘要翻译： 公开了非常适合于磁记录介质的钴的磁性氧化铁颗粒，特别是对于图像记录介质及其从前体制备的方法，其在工业上是有利的。 满足以下等式（1），（2）和（3）的含钴磁性氧化铁颗粒：20

公开(公告)号：US4551327A

公开(公告)日：1985-11-05

申请号：US513033

申请日：1983-07-12

申请人： Ichiro Honma ,  Arata Koyama ,  Masatoshi Amano ,  Nobusuke Takumi

发明人： Ichiro Honma ,  Arata Koyama ,  Masatoshi Amano ,  Nobusuke Takumi

IPC分类号： C01G51/00 ,  C01G49/00 ,  C01G49/06 ,  G11B5/706 ,  H01F1/10 ,  H01F1/11

CPC分类号： G11B5/70673 ,  G11B5/70684

摘要： An aqueous slurry of a magnetic iron oxide powder is mixed with a suspension prepared by neutralizing an aqueous ferrous salt solution with an alkali to form ferrous hydroxide and then adding an aqueous cobalt salt solution thereto, and the excess OH concentration of the mixed slurry is adjusted to 0.05 to 3 mol/l, thereby obtaining a cobalt-and ferrous iron-containing ferromagnetic iron oxide. The cobalt-and ferrous iron-containing ferromagnetic iron oxide is excellent in coercivity, distribution of coercivity and other magnetic properties, and the magnetic tape produced by using such iron oxide is also excellent in coercivity and switching field distribution.

摘要翻译： 将磁性氧化铁粉末的水性浆料与通过用碱中和亚铁盐水溶液制备的悬浮液混合形成氢氧化亚铁，然后向其中加入钴盐水溶液，并调节混合浆料的过量OH浓度 至0.05至3mol / l，从而获得含铁和含铁铁的铁磁性氧化铁。 含钴铁和含铁铁的铁磁性氧化铁的矫顽力，矫顽力分布等磁性能优异，通过使用这种氧化铁制造的磁带也具有优异的矫顽力和切换场分布。

公开(公告)号：US5041307A

公开(公告)日：1991-08-20

申请号：US442223

申请日：1989-11-28

申请人： Arata Koyama ,  Makoto Ogasawara ,  Shigeru Takatori

发明人： Arata Koyama ,  Makoto Ogasawara ,  Shigeru Takatori

IPC分类号： G11B5/706

CPC分类号： G11B5/70684 ,  G11B5/70663 ,  G11B5/70668

摘要： A process for producing magnetic ion oxide particles for magnetic rcording which comprises heat-treating a magnetic iron oxide particles of magnetite, berthollide or maghemite as a starting materials, in the presence of a zinc component or both a zinc component and a silicon component at a temperature of 400.degree. to 700.degree. C. in a specific atmosphere, and if necessary, subjecting the heat-treated particles to wet treatment and/or dry treatment, thereby doping the particles with zinc ions resulting in magnetic iron oxide particles having an improved saturation magnetization, a proportion of said zinc ions being 2 to 9 at. % by weight relative to the total amount of iron ions.

公开(公告)号：US4414245A

公开(公告)日：1983-11-08

申请号：US401214

申请日：1982-07-23

申请人： Kokichi Miyazawa ,  Kazuo Nakata ,  Tsuneo Ishikawa ,  Ichiro Honma ,  Arata Koyama ,  Masatoshi Amano

发明人： Kokichi Miyazawa ,  Kazuo Nakata ,  Tsuneo Ishikawa ,  Ichiro Honma ,  Arata Koyama ,  Masatoshi Amano

IPC分类号： C01G49/02 ,  G11B5/706 ,  C01G49/06 ,  B05D5/12

CPC分类号： G11B5/70684 ,  G11B5/70673

摘要： A process which comprises coating a cobalt compound or a combination of a cobalt compound and a ferrous compound on the surface of magnetic iron oxide particles and then heating the coated particles in the presence of water vapor. The cobalt containing ferromagnetic iron oxide produced by this process is excellent in coercivity and thermal stability. Further, magnetic tape produced from this iron oxide has a high coercivity and is excellent in squareness, orientability and remanent induction.

摘要翻译： 一种方法，其包括在磁性氧化铁颗粒的表面上涂覆钴化合物或钴化合物和亚铁化合物的组合，然后在水蒸气存在下加热涂覆的颗粒。 通过该方法生产的含铁的铁磁性氧化铁具有优异的矫顽力和热稳定性。 此外，由该氧化铁制成的磁带具有高的矫顽力，并且具有优异的矩形性，取向性和残留感应性。

公开(公告)号：US4486467A

公开(公告)日：1984-12-04

申请号：US449692

申请日：1982-12-14

申请人： Kazuo Nakata ,  Tsuneo Ishikawa ,  Ichiro Honma ,  Arata Koyama ,  Masaharu Hirai ,  Masatoshi Amano

发明人： Kazuo Nakata ,  Tsuneo Ishikawa ,  Ichiro Honma ,  Arata Koyama ,  Masaharu Hirai ,  Masatoshi Amano

IPC分类号： C01G49/02 ,  G11B5/706

CPC分类号： G11B5/70673 ,  G11B5/70684

摘要： A phosphorus-containing magnetic iron oxide powder is subjected to the activation with an aqueous alkaline medium under pressure and then coated with a cobalt compound or a cobalt compound and other metallic compound(s) to produce a cobalt-containing magnetic iron oxide powder. The magnetic iron oxide powder obtained according to this process finds its best application to the production of magnetic recording media.

摘要翻译： 将含磷磁性氧化铁粉末在含水碱性介质的压力下进行活化，然后用钴化合物或钴化合物和其它金属化合物涂覆以制备含钴磁性氧化铁粉末。 根据该方法得到的磁性氧化铁粉末，最适用于制造磁记录介质。