公开(公告)号：US5968405A

公开(公告)日：1999-10-19

申请号：US880676

申请日：1997-06-23

申请人： Minoru Yamasaki ,  Katsunori Fujimoto ,  Toshitada Shigemura ,  Katsumi Yamashita

发明人： Minoru Yamasaki ,  Katsunori Fujimoto ,  Toshitada Shigemura ,  Katsumi Yamashita

IPC分类号： C01G49/00 ,  G11B5/712 ,  H01F1/11

CPC分类号： H01F1/112 ,  G11B5/712 ,  Y10T428/2991

摘要： Cobalt-coated acicular magnetic iron oxide particles of the present invention have an average major axial diameter of 0.15 to 0.50 .mu.m, and comprise:as seed crystal particles, acicular magnetic iron oxide particles containing 0.05 to 1.0 wt % of phosphorus, calculated as P, based on the weight of the cobalt-coated acicular magnetic iron oxide particles;as inner layers, spinel ferrite layers containing cobalt formed on the surfaces of said seed crystal particles; andas outer layers, coating layers comprising a hydroxide of magnesium formed on said spinel ferrite layers.Such cobalt-coated acicular magnetic iron oxide particles show a smaller change of coercive force with temperature, have a small switching field distribution and, hence, are suitable as magnetic particles for magnetic recording media.

摘要翻译： 本发明的钴包覆的针状磁性氧化铁颗粒的平均主轴径为0.15〜0.50μm，包括：作为晶种颗粒，含有0.05〜1.0重量％磷的针状磁性氧化铁颗粒，计算为P ，基于钴涂覆的针状磁性氧化铁颗粒的重量; 作为内层，在所述晶种颗粒的表面上形成含有钴的尖晶石铁氧体层; 并且作为外层，包含在所述尖晶石铁素体层上形成的包含镁的氢氧化物的涂层。 这种钴涂覆的针状磁性氧化铁颗粒随着温度显示出矫顽力变化较小，开关场分布小，因此适用于磁记录介质的磁性颗粒。

公开(公告)号：US4851292A

公开(公告)日：1989-07-25

申请号：US8439

申请日：1987-01-29

申请人： Norimichi Nagai ,  Akihiko Hirayama ,  Norio Sugita ,  Masao Kiyama ,  Toshio Takada ,  Katsunori Fujimoto ,  Yasutaka Ota

发明人： Norimichi Nagai ,  Akihiko Hirayama ,  Norio Sugita ,  Masao Kiyama ,  Toshio Takada ,  Katsunori Fujimoto ,  Yasutaka Ota

IPC分类号： G11B5/706

CPC分类号： G11B5/70678 ,  Y10S428/90 ,  Y10T428/2982 ,  Y10T428/2991

摘要： Disclosed herein are plate-like barium ferrite particles with a solid solution of zinc on the surface thereof, which have an average particle diameter of not less than 0.03 .mu.m and less than 0.1 .mu.m, a BET specific surface are of 55 to 80 m.sup.2 /g, a coercive force of 300 to 1,500 Oe and a magnetization of not less than 57 emu/g, preferably not less than 60 emu/g, in magnetic field of 10 KOe, and which are represented by the following formula (I):BaO.n[(Fe.sub.1-x-y Co.sub.x Ti.sub.y).sub.2 O.sub.3-x+y ] (I)wherein x and y are independently from 0.02 to 0.12 and n is from 4 to 11, the atomic ratio of Co to Fe(III) being from 0.02:1 to 0.13:1 and the molar ratio of Ti to Co being from more than 0 to not more than 0.8, and a process for producing the plate-like barium ferrite particles.

公开(公告)号：US4781981A

公开(公告)日：1988-11-01

申请号：US129628

申请日：1987-12-07

申请人： Tsutomu Katamoto ,  Norimichi Nagai ,  Yasutaka Ota ,  Katsunori Fujimoto ,  Akihiko Hirayama ,  Masao Kiyama

发明人： Tsutomu Katamoto ,  Norimichi Nagai ,  Yasutaka Ota ,  Katsunori Fujimoto ,  Akihiko Hirayama ,  Masao Kiyama

IPC分类号： G11B5/706 ,  C04B35/26

CPC分类号： G11B5/70678 ,  Y10T428/2991

摘要： Disclosed herein are Ba-containing plate-like magnetoplumbite type ferrite particles for magnetic recording containing ions of one metal (II) selected from Ni and Zn and ions of one metal (IV) selected from Ti, Sn and Zr, and having zinc incorporated as a solid solution close to the particle surface and the change of coercive force of said particles at a temperature of -20.degree. to 120.degree. C. in the range of -0.5 to +0.5 Oe/.degree.C., and a process for producing the same.

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：US4752407A

公开(公告)日：1988-06-21

申请号：US7760

申请日：1987-01-28

申请人： Norimichi Nagai ,  Katsunori Fujimoto ,  Yasutaka Ota ,  Masao Kiyama ,  Toshio Takada

发明人： Norimichi Nagai ,  Katsunori Fujimoto ,  Yasutaka Ota ,  Masao Kiyama ,  Toshio Takada

IPC分类号： C01G49/00 ,  G11B5/706 ,  H01F1/11 ,  C04B35/26

CPC分类号： B82Y30/00 ,  C01G49/009 ,  G11B5/70678 ,  H01F1/11 ,  C01P2002/32 ,  C01P2004/04 ,  C01P2004/20 ,  C01P2004/64 ,  C01P2006/12 ,  C01P2006/42

摘要： Disclosed herein are plate-like barium particles which are suitable for use in precursor of sintered magnets and magnetic recording media, which have an average particle diameter of not less than 0.03 .mu.m and less than 0.1 .mu.m, and which are represented by the following formula (I):BaO.n[Fe.sub.1-x-y Co.sub.x Ti.sub.y).sub.2 O.sub.3-x+y ] (i)wherein x and y are independently from 0.02 to 0.12 and n is from 4 to 7, the atomic ratio of Co to Fe(III) being from 0.02:1 to 0.13:1 and the molar ratio of Ti to Co being from more than 0 to not more than 0.8, and a process for producing the plate-like barium ferrite particles.

摘要翻译： 本文公开了适用于平均粒径不小于0.03μm且小于0.1μm的烧结磁体和磁记录介质的前体的板状钡颗粒，并且由以下 式（I）：BaO.n [Fe1-x-yCoxTiy] 2O3-x + y]（i）其中x和y独立地为0.02〜0.12，n为4〜7，Co与Fe的原子比（ III）为0.02:1至0.13:1，Ti与Co的摩尔比大于0至不大于0.8，以及制备板状钡铁氧体颗粒的方法。

公开(公告)号：US5599378A

公开(公告)日：1997-02-04

申请号：US450205

申请日：1995-05-25

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 ,  H01F1/11 ,  H01F1/36

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：US4806429A

公开(公告)日：1989-02-21

申请号：US8466

申请日：1987-01-29

申请人： Norimichi Nagai ,  Akihiko Hirayama ,  Norio Sugita ,  Masao Kiyama ,  Toshio Takada ,  Katsunori Fujimoto ,  Yasutaka Ota

发明人： Norimichi Nagai ,  Akihiko Hirayama ,  Norio Sugita ,  Masao Kiyama ,  Toshio Takada ,  Katsunori Fujimoto ,  Yasutaka Ota

IPC分类号： G11B5/706 ,  B32B5/16

CPC分类号： G11B5/70678 ,  Y10S428/90 ,  Y10T428/2982 ,  Y10T428/2991

摘要： Disclosed herein are plate-like barium ferrite particles with a solid solution of zinc on the surface thereof, which have an average particle diameter of 0.05 to 0.3 .mu.m, a coercive force of 300 to 1,500 Oe and a magnetization of not less than 55 emu/g in magnetic field of 10 KOe, and which are represented by the following formula (I):BaO.multidot.n[(Fe.sub.1-2x Co.sub.x Ti.sub.x).sub.2 O.sub.3 ](I)wherein x is 0 to 0.1 and n is from 4 to 11, the molar ratio of Ti to Co being 1, and a process for producing the plate-like barium ferrite particles.

摘要翻译： 本文公开了具有锌表面固溶体的板状钡铁氧体颗粒，其平均粒径为0.05〜0.3μm，矫顽力为300〜1500Oe，磁化强度为55emu以上 （I）表示：BaOxn [（Fe1-2xCoxTix）2O3]（I）其中x为0〜0.1，n为4〜11，摩尔比 的Ti至Co为1，以及制备板状钡铁氧体颗粒的方法。