公开(公告)号：US5079092A

公开(公告)日：1992-01-07

申请号：US556697

申请日：1990-07-24

申请人： Masaaki Maekawa ,  Norimichi Nagai ,  Norio Sugita

发明人： Masaaki Maekawa ,  Norimichi Nagai ,  Norio Sugita

IPC分类号： G11B5/706

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

摘要： Disclosed herein are plate-like composite ferrite fine particles for magnetic recording comprising plate-like composite ferrite containing Ba fine particles which contain Ti of 2 to 5.0 atomic % based on Fe.sup.3+ and Ni in the range of 1.2.ltoreq.Ni/Ti.ltoreq.4 by molar ratio, which have zinc in the vicinity of the particles surfaces in the form of a solid solution, which have an average particle diameter of 0.01 .mu.m to 0.08 .mu.m, and the coercive force of which scarcely varies with the rise in temperature in the temperature range of -20.degree. C. to 120.degree. C., and a process for producing such plate-like composite ferrite fine particles.

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：US4698182A

公开(公告)日：1987-10-06

申请号：US654194

申请日：1984-09-24

申请人： Norimichi Nagai ,  Nanao Horiishi ,  Masao Kiyama ,  Toshio Takada

发明人： Norimichi Nagai ,  Nanao Horiishi ,  Masao Kiyama ,  Toshio Takada

IPC分类号： C01G49/02 ,  C01G49/00 ,  C09D5/23 ,  C09D7/12 ,  G11B5/706 ,  G11B5/708 ,  G11B5/714 ,  H01F1/11 ,  C04B35/26

CPC分类号： G11B5/714 ,  G11B5/70678

摘要： Disclosed herein are hexagonal plate-like barium ferrite particles for magnetic recording, represented by the formula: BaFe.sub.12-x-y M.sub.x Ti.sub.y O.sub.19 wherein x and y are independently 0.6 to 1.2 and M is Co(II) or Co(II) and a divalent metal other than Co, having the width of the particle of 0.1 to 0.4 micrometer and a BET specific surface area (S) of 20 to 50 m.sup.2 /g, and showing a magnetization (M) of larger than 40 emu/g in a magnetic field of 10 KOe and a coercive force (Hc) of 500 to 1000 Oe, and a process for producing the same.

摘要翻译： 本文公开了用于磁记录的六角形板状钡铁氧体颗粒，其由下式表示：BaFe12-x-yMxTiyO19，其中x和y独立地为0.6至1.2，M为Co（II）或Co（II）和二价金属其他 比Co的宽度为0.1〜0.4微米，BET比表面积（S）为20〜50m 2 / g，在磁场中的磁化强度（M）大于40emu / g 10KOe和500〜1000Oe的矫顽力（Hc）及其制造方法。

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：US5238483A

公开(公告)日：1993-08-24

申请号：US921093

申请日：1992-07-29

申请人： Akio Mishima ,  Mamoru Tanihara ,  Yasutaka Ota ,  Hirofumi Kawasaki ,  Kenji Okinaka ,  Kunio Ikemoto ,  Kousaku Tamari ,  Kohji Mori ,  Norimichi Nagai

发明人： Akio Mishima ,  Mamoru Tanihara ,  Yasutaka Ota ,  Hirofumi Kawasaki ,  Kenji Okinaka ,  Kunio Ikemoto ,  Kousaku Tamari ,  Kohji Mori ,  Norimichi Nagai

IPC分类号： G11B5/706

CPC分类号： G11B5/70615

摘要： Disclosed herein are acicular magnetic iron based alloy particles for magnetic recording, containing 1.5 to 10 mol % of B based on Fe (calculated as B) and 1.5 to 10 mol % of Co based on Fe (calculated as Co) in the vicinity of the surfaces of said particles and having a saturation magnetization of not less than 125 emu/g and an S.F.D. value of not more than 0.50, and a process for producing the same.

摘要翻译： 本文公开了用于磁记录的针状磁性铁基合金颗粒，其含有1.5至10mol％的基于Fe的B（以B计）和1.5至10mol％的基于Fe（以Co计算）的Co在附近 所述颗粒的表面具有不小于125emu / g的饱和磁化强度和SFD 值不大于0.50，及其制造方法。

公开(公告)号：US5156922A

公开(公告)日：1992-10-20

申请号：US728328

申请日：1991-07-08

申请人： Akio Mishima ,  Mamoru Tanihara ,  Yasutaka Ota ,  Hirofumi Kawasaki ,  Kenji Okinaka ,  Kunio Ikemoto ,  Kousaku Tamari ,  Kohji Mori ,  Norimichi Nagai

发明人： Akio Mishima ,  Mamoru Tanihara ,  Yasutaka Ota ,  Hirofumi Kawasaki ,  Kenji Okinaka ,  Kunio Ikemoto ,  Kousaku Tamari ,  Kohji Mori ,  Norimichi Nagai

IPC分类号： G11B5/706

CPC分类号： G11B5/70615 ,  Y10T428/12181

摘要： Disclosed herein are acicular magnetic iron based alloy particles for magnetic recording, containing 1.5 to 10 mol % of B based on Fe (calculated as B) and 1.5 to 10 mol % of Co based on Fe (calculated as Co) in the vicinity of the surfaces of said particles and having a saturation magnetization of not less than 125 emu/g and an S.F.D. value of not more than 0.50, and a process for producing the same.

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：US4529524A

公开(公告)日：1985-07-16

申请号：US666253

申请日：1984-10-29

申请人： Norimichi Nagai ,  Nanao Horiishi ,  Masao Kiyama ,  Toshio Takada

发明人： Norimichi Nagai ,  Nanao Horiishi ,  Masao Kiyama ,  Toshio Takada

IPC分类号： C09D5/23 ,  C01G49/00 ,  C01G51/00 ,  C09D7/12 ,  G11B5/706 ,  H01F1/11 ,  C04B35/26

CPC分类号： B82Y30/00 ,  C01G49/0036 ,  C01G49/0063 ,  C01G49/0072 ,  C01G49/009 ,  C01G51/006 ,  G11B5/70678 ,  C01P2002/54 ,  C01P2004/20 ,  C01P2004/62 ,  C01P2004/64 ,  C01P2006/12 ,  C01P2006/42 ,  C01P2006/60 ,  C01P2006/80

摘要： Disclosed herein is a process for producing plate-like barium ferrite particles for magnetic recording, represented by the formula:BaFe.sub.12-x-y M.sub.x Ti.sub.y O.sub.19wherein x and y are independently not more than 1.2 and M is Co(II) or Co(II) and a divalent metal other than Co, which comprises adding a compound of Si(IV) to an aqueous highly alkaline suspension of ferric hydroxide containing Ti(IV), Ba(II) and Co(II) or Co(II) and a divalent metal other than Co as M(II), and autoclaving the resultant aqueous highly alkaline suspension of ferric hydroxide at the temperature of 200.degree. to 330.degree. C., thereby obtaining the plate-like barium ferrite particles having the thickness thereof controlled according to the atomic ratio of Si(IV) to Fe(III).

摘要翻译： 本发明公开了一种用于制备用于磁记录的板状钡铁氧体颗粒的方法，由下式表示：BaFe12-x-yMxTiyO19，其中x和y独立地不大于1.2，M是Co（II）或Co（II），和 除了Co之外的二价金属，其包括将Si（IV）的化合物加入到含有Ti（IV），Ba（II）和Co（II）或Co（II）的氢氧化铁的高碱性悬浮液和二价金属 除了Co为M（II）以外，在200〜330℃的温度下高压蒸馏所得的氢氧化铁水溶液高碱性悬浮液，由此得到其厚度根据原子的量控制的板状钡铁氧体颗粒 Si（IV）与Fe（III）的比例。

公开(公告)号：US5075169A

公开(公告)日：1991-12-24

申请号：US358019

申请日：1989-05-30

申请人： Norimichi Nagai ,  Norio Sugita

发明人： Norimichi Nagai ,  Norio Sugita

IPC分类号： G11B5/706 ,  G11B5/712

CPC分类号： G11B5/70678 ,  G11B5/70657 ,  G11B5/712 ,  Y10T428/2982 ,  Y10T428/2991

摘要： Disclosed herein are plate-like composite ferrite particles for magnetic recording comprising plate-like composite ferrite containing Ba particles having a composition represented by 19

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.