公开(公告)号：US4136158A

公开(公告)日：1979-01-23

申请号：US847446

申请日：1977-11-01

申请人： Yosiro Okuda ,  Nanao Horiishi ,  Hiroshi Sumita ,  Tosiharu Harada

发明人： Yosiro Okuda ,  Nanao Horiishi ,  Hiroshi Sumita ,  Tosiharu Harada

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

CPC分类号： G11B5/70663 ,  C01G49/06 ,  C01P2004/54 ,  C01P2004/62 ,  C01P2006/42

摘要： In the production of acicular ferromagnetic iron oxide of highly uniform particle size by oxidizing an iron (II) hydroxide suspension at a pH of at least 11 with an oxygen-containing gas to form acicular iron (III) oxide hydroxide, reducing and optionally further reoxidizing this into ferromagnetic iron oxide, the improvement which comprises providing the iron (II) hydroxide suspension with a water-soluble silicate in an amount of less than 1.7% by atom based on the amount of the iron (II) hydroxide in the suspension and calculated as the ratio of Si to Fe (II) while prior to the oxidation of the suspension with the oxygen-containing gas.

公开(公告)号：US4873010A

公开(公告)日：1989-10-10

申请号：US039775

申请日：1987-04-15

申请人： Atsushi Takedoi ,  Hiroyuki Kondo ,  Masaru Isoai ,  Yoshitaka Yoshinaga ,  Tosiharu Harada ,  Yosiro Okuda ,  Hiroshi Sumita ,  Hirofumi Kawasaki ,  Kohji Mori

发明人： Atsushi Takedoi ,  Hiroyuki Kondo ,  Masaru Isoai ,  Yoshitaka Yoshinaga ,  Tosiharu Harada ,  Yosiro Okuda ,  Hiroshi Sumita ,  Hirofumi Kawasaki ,  Kohji Mori

IPC分类号： G11B5/706

CPC分类号： G11B5/70689 ,  G11B5/70652

摘要： Disclosed herein are magnetic iron oxide particles comprising spindle-like magnetite or maghemite particles having an aspect ratio(major:minor) of less than 4:1 and containing 0.1 to 20 atomic % of Si to Fe, and a process for producing the same.

摘要翻译： 本文公开了包含具有小于4:1的纵横比（主要：次要）且包含0.1至20原子％的Si与Fe的纺锤状磁铁矿或磁赤铁矿颗粒的磁性氧化铁颗粒及其制备方法。

公开(公告)号：US4495164A

公开(公告)日：1985-01-22

申请号：US512661

申请日：1983-07-11

申请人： Yosiro Okuda ,  Tosiharu Harada

发明人： Yosiro Okuda ,  Tosiharu Harada

IPC分类号： C01G49/06 ,  C01G49/08 ,  G11B5/706

CPC分类号： C01G49/06 ,  C01G49/08 ,  G11B5/70678 ,  C01P2004/03 ,  C01P2004/10 ,  C01P2004/54 ,  C01P2004/61 ,  C01P2004/62 ,  C01P2006/42

摘要： A process for producing acicular magnetite or maghemite of high axial ratio, which comprisespreparing an iron (II) hydroxide suspension at a pH of at least 11 with a magnesium sulfate or magnesium chloride in an amount of 0.5 to 7.0 atomic % based on the amount of the iron (II) hydroxide in the suspension and calculated as the ratio of Mg to Fe (II),oxidizing the resultant suspension with the oxygen-containing gas to form an acicular iron (III) oxide hydroxide in the form of particles having a long axis length of 0.3 to 2.0 .mu.m and an axial ratio of more than 20:1,reducing said acicular iron (III) oxide hydroxide into the acicular magnetite, and oxidizing the resultant acicular magnetite to form the acicular maghemite, if necessary.

摘要翻译： 一种制备高轴比的针状磁铁矿或磁赤铁矿的方法，其包括以0.5至7.0原子％的量以硫酸镁或氯化镁制备pH至少为11的氢氧化铁（II）悬浮液， 的悬浮液中的氢氧化铁（II），并以Mg与Fe（II）的比例计算，用含氧气体氧化所得的悬浮液，形成具有下列物质的颗粒形式的针状（III）氧化物氢氧化物 长轴长度为0.3〜2.0μm，轴比为20:1以上，将针状铁氧化物氢氧化物还原成针状磁铁矿，并根据需要氧化所得针状磁铁矿以形成针状磁赤铁矿。

公开(公告)号：US4406694A

公开(公告)日：1983-09-27

申请号：US285983

申请日：1981-07-23

申请人： Akio Mishima ,  Yosiro Okuda ,  Tosiharu Harada ,  Akira Mukaizaka

发明人： Akio Mishima ,  Yosiro Okuda ,  Tosiharu Harada ,  Akira Mukaizaka

IPC分类号： G11B5/62 ,  B22F1/00 ,  B22F9/22 ,  C09D5/23 ,  C09D7/12 ,  C22C38/00 ,  H01F1/06 ,  B22F1/02 ,  B22F9/18

CPC分类号： H01F1/065

摘要： A process for producing an acicular ferromagnetic alloy particles mainly containing iron and magnesium, which comprises preparing a suspension of iron(II) hydroxide and water-soluble magnesium salt, the suspension having a pH value of at least 11 and containing the magnesium salt in an amount of 0.5 to 20.0 atomic % based on the amount of the iron(II) hydroxide in the suspension and calculated as the ratio of Mg to Fe(II), oxidizing the suspension with an oxygen-containing gas to form an acicular particles of iron(III) oxide hydroxide substituted with magnesium, forming coats of phosphorus compound and subsequent silicon compound on the acicular particles, heating the resultant particle at 500.degree. to 900.degree. C. under a non-reducing atmosphere and then reheating the particle thus treated at 350.degree. to 600.degree. C. under reducing atmosphere.

摘要翻译： 一种主要含铁和镁的针状铁磁性合金颗粒的制造方法，包括制备氢氧化铁（II）和水溶性镁盐的悬浮液，所述悬浮液的pH值至少为11，并含有镁盐 相对于悬浮液中的氢氧化铁（II）的量为0.5〜20.0原子％，以Mg与Fe（II）的比例计算，用含氧气体氧化悬浮液，形成针状的铁粒子 （III）氧化物氢氧化物，用镁取代，在针状颗粒上形成磷化合物和随后的硅化合物的涂层，在非还原气氛下在500-900℃下加热所得颗粒，然后在350℃下再加热处理的颗粒 在还原气氛下，温度为600℃。

公开(公告)号：US5480571A

公开(公告)日：1996-01-02

申请号：US309743

申请日：1994-09-21

申请人： Masaru Isoai ,  Tosiharu Harada ,  Tokihiro Kurata ,  Kazuhiro Fujita ,  Kazushi Takama ,  Shigekazu Jikuhara

发明人： Masaru Isoai ,  Tosiharu Harada ,  Tokihiro Kurata ,  Kazuhiro Fujita ,  Kazushi Takama ,  Shigekazu Jikuhara

IPC分类号： C01G49/06 ,  C01G49/08

CPC分类号： B82Y30/00 ,  C01G49/06 ,  C01G49/08 ,  C01P2004/03 ,  C01P2004/10 ,  C01P2004/51 ,  C01P2004/54 ,  C01P2004/62 ,  C01P2004/64 ,  C01P2006/42

摘要： Disclosed herein are a process for producing acicular goethite particles comprising the step off: 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, an aqueous alkali carbonate solution, or an aqueous alkali hydroxide and alkali carbonate solution based on Fe.sup.2+ in said aqueous ferrous salt solution, in the presence of ascorbic acid or a salt thereof so as to oxidize said colloidal ferrous hydroxide or iron-containing colloidal precipitates and to produce acicular goethite particles throught green rust; 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+.

摘要翻译： 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 一种碱金属氢氧化物水溶液，碱金属碳酸盐水溶液或碱金属氢氧化物和碱金属碳酸盐水溶液中，在所述含水亚铁盐水溶液中，在抗坏血酸或其盐的存在下，氧化所述胶体 含氢氧化铁或含铁胶体沉淀物，并通过绿锈生成针状针铁矿颗粒; 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。

公开(公告)号：US5466306A

公开(公告)日：1995-11-14

申请号：US118287

申请日：1993-09-09

申请人： Akio Mishima ,  Tosiharu Harada ,  Mamoru Tanihara ,  Yasutaka Ota ,  Kenji Okinaka ,  Kohji Mori ,  Hirofumi Kawasaki ,  Norimichi Nagai ,  Katsunori Fujimoto ,  Yoshiro Okuda

发明人： Akio Mishima ,  Tosiharu Harada ,  Mamoru Tanihara ,  Yasutaka Ota ,  Kenji Okinaka ,  Kohji Mori ,  Hirofumi Kawasaki ,  Norimichi Nagai ,  Katsunori Fujimoto ,  Yoshiro Okuda

IPC分类号： G11B5/706 ,  G11B5/714 ,  H01F1/06

CPC分类号： G11B5/70621 ,  G11B5/70615 ,  G11B5/714 ,  H01F1/061

摘要： Disclosed herein are spindle-shaped magnetic iron based alloy particles containing at least one selected from the group consisting of Ni, Al, Si, P, Co, Mg, B and Zn, which have a particle length of 0.05 to 0.40 .mu.m, a crystallite size of 110 to 180 .ANG., a specific surface area of 30 to 60 m.sup.2 /g, a coercive force of 1,300 to 1,700 Oe and a saturation magnetization (.sigma.s) of not less than 100 emu/g and a process for producing the same.

摘要翻译： 本文公开了含有选自Ni，Al，Si，P，Co，Mg，B和Zn中的至少一种的锭状磁铁基合金粒子，其粒径为0.05〜0.40μm，a 微晶尺寸为110〜180，比表面积为30〜60m2 / g，矫顽力为1300〜1700Oe，饱和磁化强度（sigma）为100emu / g以上， 相同。

公开(公告)号：US5399278A

公开(公告)日：1995-03-21

申请号：US22844

申请日：1993-02-25

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

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

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

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

摘要： 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 +.

摘要翻译： 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。

公开(公告)号：US4437881A

公开(公告)日：1984-03-20

申请号：US513866

申请日：1983-07-14

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

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

IPC分类号： G11B5/706 ,  B22F9/22

CPC分类号： G11B5/70615

摘要： 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.

摘要翻译： 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。

公开(公告)号：US5378380A

公开(公告)日：1995-01-03

申请号：US22847

申请日：1993-02-25

申请人： Masaru Isoai ,  Tosiharu Harada ,  Tokihiro Kurata ,  Kazuhiro Fujita ,  Kazushi Takama ,  Shigekazu Jikuhara

发明人： Masaru Isoai ,  Tosiharu Harada ,  Tokihiro Kurata ,  Kazuhiro Fujita ,  Kazushi Takama ,  Shigekazu Jikuhara

IPC分类号： C01G49/06 ,  C01G49/08

CPC分类号： B82Y30/00 ,  C01G49/06 ,  C01G49/08 ,  C01P2004/03 ,  C01P2004/10 ,  C01P2004/51 ,  C01P2004/54 ,  C01P2004/62 ,  C01P2004/64 ,  C01P2006/42

摘要： Disclosed herein are a process for producing acicular goethite particles comprising the step 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, an aqueous alkali carbonate solution, or an aqueous alkali hydroxide and alkali carbonate solution based on Fe.sup.2+ in said aqueous ferrous salt solution, in the presence of ascorbic acid or a salt thereof so as to oxidize said colloidal ferrous hydroxide or iron-containing colloidal precipitates and to produce acicular goethite particles throught green rust; 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+.

摘要翻译： 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 一种碱金属氢氧化物水溶液，碱金属碳酸盐水溶液或碱金属氢氧化物和碱金属碳酸盐水溶液中，在所述含水亚铁盐水溶液中，在抗坏血酸或其盐的存在下，氧化所述胶体 含氢氧化铁或含铁胶体沉淀物，并通过绿锈生成针状针铁矿颗粒; 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。

公开(公告)号：US6153296A

公开(公告)日：2000-11-28

申请号：US266018

申请日：1999-03-11

申请人： Kazuyuki Hayashi ,  Keisuke Iwasaki ,  Tosiharu Harada ,  Hiroko Morii

发明人： Kazuyuki Hayashi ,  Keisuke Iwasaki ,  Tosiharu Harada ,  Hiroko Morii

IPC分类号： C01G49/00 ,  C01G49/06 ,  G11B5/733

CPC分类号： C01G49/06 ,  B82Y30/00 ,  C01G49/0018 ,  G11B5/738 ,  C01P2002/54 ,  C01P2004/10 ,  C01P2004/54 ,  C01P2004/62 ,  C01P2004/64 ,  C01P2006/12 ,  C01P2006/22 ,  C01P2006/42 ,  Y10S428/90 ,  Y10T428/256 ,  Y10T428/257 ,  Y10T428/2982 ,  Y10T428/2991

摘要： Acicular hematite particles of the present invention contain zirconium of 0.05 to 30% by weight (calculated as Zr) based on the total weight of the particles, which is present within the particle, which have an average major axis diameter of not more than 0.3 .mu.m and a pH value of not less than 8, and contain not more than 300 ppm of soluble sodium salt, calculated as Na and not more than 150 ppm of soluble sulfate, calculated as SO.sub.4.Such acicular hematite particles are suitable as non-magnetic particles for a non-magnetic undercoat layer of a magnetic recording medium which exhibits a low light transmittance, an excellent smooth surface, a high strength and an excellent durability, and can be prevented from being deteriorated in magnetic properties due to the corrosion of magnetic acicular metal particles containing iron as a main component which are dispersed in a magnetic recording layer thereof.

摘要翻译： 本发明的针状赤铁矿颗粒含有基于颗粒内存在的平均长径不大于0.3μm的颗粒总重量为0.05〜30重量％（以Zr计算）的锆 m，pH值不小于8，并且含有不大于300ppm的可溶性钠盐，以Na计，不超过150ppm的可溶性硫酸盐，以SO 4计算。 这种针状赤铁矿颗粒适用于磁记录介质的非磁性底涂层的非磁性颗粒，其表现出低的透光率，优异的光滑表面，高强度和优异的耐久性，并且可以防止劣化 由于以分散在其磁记录层中的以铁为主要成分的磁性针状金属颗粒的腐蚀而导致的磁特性。