With Group I Metal Patents (Class 252/62.6)
  • Patent number: 7011764
    Abstract: A magnetic device and method for making it involve a magnetic device specifically constructed of grains in a matrix. The matrix may be cement or plaster. The grains have an average diameter that is greater than their magnetic domains. The device may be applied to shielding applications for frequencies ranging from 100 kHz to 10 GHz. The shielding may be applied to walls of a building, consumer products such as magnetic disks, and the like. The grains may be any ferromagnetic material, including ferrite.
    Type: Grant
    Filed: July 25, 2003
    Date of Patent: March 14, 2006
    Assignee: Epcos AG
    Inventors: Mauricio Esguerra, Ralph Lucke
  • Patent number: 6984338
    Abstract: An Mn—Zn ferrite includes base components of 44.0 to 49.8 mol % Fe2O3, 4.0 to 26.5 mol % ZnO, 0.8 mol % or less Mn2O3, and the remainder consisting of MnO, and contains 0.20 (0.20 excluded) to 1.00 mass % CaO as additive. Since the Mn—Zn ferrite contains less than 50.0 mol % Fe2O3 and a limited amount (0.8 mol % or less) of Mn2O3, an abnormal grain growth does not occur even if CaO content is more than 0.20 mass %, and a high electrical resistance can be gained thereby realizing an excellent soft magnetism in a high frequency band such as 1 MHz.
    Type: Grant
    Filed: January 28, 2004
    Date of Patent: January 10, 2006
    Assignee: Minebea Co., Ltd.
    Inventors: Osamu Kobayashi, Osamu Yamada, Kiyoshi Ito
  • Patent number: 6940381
    Abstract: A Mn—Zn based ferrite having a main component comprised of 51 to 54 mol % of an iron oxide in Fe2O3 conversion, 14 to 21 mol % of a zinc oxide in ZnO conversion and the rest of a manganese oxide, wherein a content (? [ppm]) of cobalt oxide in a CoO conversion with respect to 100 wt % of the main component satisfies a relation formula below. Relation formula: Y1???Y2??(1) Note that Y1 and Y2 are expressed by the formulas below and CoO>0 [ppm]. Y1=(?0.13·B2+1.5·B?15.6A+850)/(0.0003·B+0.0098)?233??(2) Y2=(?0.40·B2+4.6·B?46.7A+2546)/(0.0003·B+0.0098)+1074??(3) The A and B in the above Y1 and Y2 are A=Fe2O3 (mol %) and B=ZnO (mol %).
    Type: Grant
    Filed: December 11, 2003
    Date of Patent: September 6, 2005
    Assignee: TDK Corporation
    Inventors: Masahiko Watanabe, Katsushi Yasuhara
  • Patent number: 6908568
    Abstract: An oxide magnetic material is prepared by wet molding in a magnetic field a slurry containing a particulate oxide magnetic material, water and a polyhydric alcohol having the formula: Cn(OH)nHn+2 wherein n is from 4 to 100 as a dispersant. By improving the orientation in a magnetic field upon wet molding using water, an oxide magnetic material having a high degree of orientation, typically an anisotropic ferrite magnet, is obtained at a high rate of productivity. The method is advantageous from the environmental and economical standpoints.
    Type: Grant
    Filed: June 17, 2002
    Date of Patent: June 21, 2005
    Assignee: TDK Corporation
    Inventors: Kiyoyuki Masuzawa, Hitoshi Taguchi
  • Patent number: 6893581
    Abstract: A composite magnetic material contains first magnetic particles made of a first magnetic material and second magnetic particles made of a second magnetic material, the first and second magnetic particles being mixed with each other. A frequency characteristic of the first magnetic material is different from that of the second magnetic material. The first and second magnetic particles are mixed so that, at a frequency of an intersecting point between a first curve representing a frequency characteristic of a real part of a complex magnetic permeability of the first magnetic material and a second curve representing a frequency characteristic of a real part of a complex magnetic permeability of the second magnetic material, a value of a real part of a complex magnetic permeability of the composite magnetic material is larger than a value of the intersecting point.
    Type: Grant
    Filed: January 28, 2003
    Date of Patent: May 17, 2005
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Takashi Umemoto, Hideki Yoshikawa, Keiichi Kuramoto, Hitoshi Hirano
  • Patent number: 6872325
    Abstract: Briefly, in accordance with one embodiment of the present invention, a process for making a magnetic composite which comprises providing a polymeric resin and a magnetic powder, the magnetic powder having a mean particle size with a value for standard deviation that is less than the value for the mean particle size of the said magnetic powder, the said magnetic composite being made by mixing said magnetic powder with said polymeric resin and molding the said mixture into a desired shape and a size and said magnetic composite having a magnetic permeability between 30 and 50. In another embodiment the present invention is a composition for a magnetic composite comprising a polymeric resin and a magnetic powder, the said powder having a mean particle size with a value of standard deviation that is less than the value of the mean particle size of the magnetic powder, wherein said magnetic composite has a magnetic permeability between about 30 and about 50.
    Type: Grant
    Filed: September 9, 2002
    Date of Patent: March 29, 2005
    Assignee: General Electric Company
    Inventors: Krisanu Bandyopadhyay, Kunj Tandon, Amit Chakrabarti
  • Patent number: 6872251
    Abstract: A method for manufacturing single crystal ceramic powder is provided. The method includes a powder supply step for supplying powder consisting essentially of ceramic ingredients to a heat treatment area with a carrier gas, a heat treatment step for heating the powder supplied to the heat treatment area at temperatures required for single-crystallization of the powder to form a product, and a cooling step for cooling the product obtained in the heat treatment step to form single crystal ceramic powder. The method provides single crystal ceramic powder consisting of particles with a very small particle size and a sphericity being 0.9 or higher.
    Type: Grant
    Filed: May 29, 2002
    Date of Patent: March 29, 2005
    Assignee: TDK Corporation
    Inventors: Minoru Takaya, Yoshiaki Akachi, Hiroyuki Uematsu, Hisashi Kobuke
  • Publication number: 20040229151
    Abstract: A carrier core material containing at least one metal oxide (MLO) having a melting point of not higher than 1000° C. and at least one metal oxide (MHO) having a melting point of not lower than 1800° C., wherein the metal (MH) for constituting the metal oxide (MHO) has an electrical resistivity of not less than 10−5 &OHgr;·cm. Also disclosed is a two-component developing agent comprising a coated carrier, which comprises the carrier core material coated with a resin, and toner particles. Further disclosed is an image forming method comprising developing an electrostatic latent image formed on a photosensitive member with the two-component developing agent using an alternating electric field. The carrier core material and the coated carrier have high magnetization and are free from occurrence of leakage of electric charge over a wide range of electric field from low electric field to high electric field.
    Type: Application
    Filed: February 6, 2004
    Publication date: November 18, 2004
    Applicant: POWDERTECH CO., LTD.
    Inventors: Hiromichi Kobayashi, Issei Shinmura, Tsuyoshi Itagoshi, Yuji Sato
  • Patent number: 6814883
    Abstract: A high frequency magnetic material includes a Y or M type hexagonal ferrite, wherein the hexagonal ferrite is expressed by the composition formula (1-a-b)(Ba1-xSrx)O.aMeO.bFe2O3, where Me is at least one selected from the group consisting of Co, Ni, Cu, Mg, Mn and Zn, 0.205≦a≦0.25, 0.55≦b≦0.595, 0≦x≦1, and 2.2≦b/a<3. A high frequency circuit element includes magnetic layers and internal electrode layers, wherein the high frequency circuit element is a sintered compact and the magnetic layers include the high frequency magnetic material.
    Type: Grant
    Filed: August 27, 2002
    Date of Patent: November 9, 2004
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Hiroshi Marusawa
  • Patent number: 6800215
    Abstract: A Ni type ferrite material of a low magnetic loss. The Ni type ferrite material is formed by adding MnO2 in an amount of 0.1 to 10 mol % to a ferrite material of a composition containing Fe2O3 in 40 to 50 mol %, ZnO in 20 to 33 mol %, CuO in 2 to 10 mol %, and NiO in the remainder. Such Ni type ferrite material is adapted for use in a coil component as a core material because of a smaller magnetic loss in comparison with a prior material, and has a high electric resistance to allow direct coil winding on the core, thereby realizing reduction in both size and weight of the coil component.
    Type: Grant
    Filed: May 23, 2003
    Date of Patent: October 5, 2004
    Assignee: FDK Corporation
    Inventors: Masayuki Inagaki, Yoshio Matsuo, Toshiaki Tomozawa
  • Publication number: 20040183049
    Abstract: An Mn—Zn ferrite includes base components of 44.0 to 49.8 mol % Fe2O3, 4.0 to 26.5 mol % ZnO, 0.8 mol % or less Mn2O3, and the remainder consisting of MnO, and contains 0.20 (0.20 excluded) to 1.00 mass % CaO as additive. Since the Mn—Zn ferrite contains less than 50.0 mol % Fe2O3 and a limited amount (0.8 mol % or less) of Mn2O3, an abnormal grain growth does not occur even if CaO content is more than 0.20 mass %, and a high electrical resistance can be gained thereby realizing an excellent soft magnetism in a high frequency band such as 1 MHz.
    Type: Application
    Filed: January 28, 2004
    Publication date: September 23, 2004
    Applicant: Minebea Co., Ltd.
    Inventors: Osamu Kobayashi, Osamu Yamada, Kiyoshi Ito
  • Patent number: 6793842
    Abstract: A ferrite fine powder having a mean particle size of 0.1 to 30 &mgr;m and made of spherical single-crystal particles. The ferrite fine powder has superior physical properties and excellent magnetic properties desirable for use as a raw material for a dust core of coils, transformers, etc. The powder is prepared by forming a solution or suspension containing a compound or compounds of at least one of the metals forming the ferrite into fine droplets, and thermally decomposing the droplets at elevated temperatures.
    Type: Grant
    Filed: July 6, 2001
    Date of Patent: September 21, 2004
    Assignees: Shoei Chemical Inc., TDK Corporation
    Inventors: Yuji Akimoto, Kazuro Nagashima, Masahiro Ikemoto, Minoru Takaya, Yoshiaki Akachi, Hisashi Kobuke
  • Patent number: 6790379
    Abstract: A magnetic ferrite composition including at least one of Mg, Ni, Cu, Zn, Mn, and Li and having a content of carbon within a predetermined range, for example, over 9.7 weight ppm to less than 96 weight ppm. The composition may be used as the magnetic core for an inductor, transformer, coil, etc. used for radios, televisions, communication devices, office automation equipment, switching power sources, and other electronic apparatuses or magnetic heads for video apparatuses or magnetic disk drives or other electronic components.
    Type: Grant
    Filed: September 12, 2003
    Date of Patent: September 14, 2004
    Assignee: TDK Corporation
    Inventors: Takuya Aoki, Takeshi Nomura
  • Publication number: 20040164269
    Abstract: A low temperature co-fired ferrite-ceramic (FECERA) composite consisting of two different dielectric materials (Ceramic and Ferrite) can be used to make a diversification combination filter component by the process of a multi-layer passive component, so that the combination filter component can prevent the function of electromagnetic interference (EMI) and has an excellent electromagnetic couple effect.
    Type: Application
    Filed: February 25, 2003
    Publication date: August 26, 2004
    Inventor: Chaby Hsu
  • Patent number: 6780555
    Abstract: Black magnetic iron oxide particles having an average particle diameter of 0.05 to 1.0 &mgr;m have a three-phase structure comprising: a core portion containing at least one metal element other than Fe selected from the group consisting of Mn, Zn, Cu, Ni, Cr, Cd, Sn, Mg, Ti, Ca and Al in an amount of 0.1 to 10% by weight based on whole Fe contained in the particles; a surface coat portion containing at least one metal element other than Fe selected from the group consisting of Mn, Zn, Cu, Ni, Cr, Cd, Sn, Mg, Ti, Ca and Al in an amount of 0.1 to 10% by weight based on whole Fe contained in the particles; and an intermediate layer disposed between the core portion and the surface coat portion, containing substantially none of the metal elements other than Fe.
    Type: Grant
    Filed: January 22, 2002
    Date of Patent: August 24, 2004
    Assignee: Toda Kogyo Corporation
    Inventors: Naoki Uchida, Minoru Kouzawa, Hiromitsu Misawa, Koso Aoki, Suehiko Miura
  • Patent number: 6767478
    Abstract: The Mn—Zn ferrite of the present invention contains basic components of 44.0 to 50.0 mol % (50.0 mol % is excluded) Fe2O3, 4.0 to 26.5 mol % ZnO and the remainder MnO, and has a real part &egr;′ of complex relative permittivity of 20,000 or less at 1 kHz and 50 or less at 1 MHz, thereby maintaining initial permeability in a wide frequency band, showing a low stray capacitance with a coil provided, and ensuring an excellent impedance in a wide frequency band. And a coil using the Mn—Zn ferrite as a magnetic core is also provided.
    Type: Grant
    Filed: August 2, 2002
    Date of Patent: July 27, 2004
    Assignee: Minebea Co., Ltd.
    Inventors: Kiyoshi Ito, Osamu Kobayashi, Yukio Suzuki
  • Patent number: 6749768
    Abstract: Provided is magnetic ferrite powder in which a peak intensity ratio of Z phase (M3Me2Fe24O41: M=one or more kinds of alkaline-earth metal, Me=one or more kinds from Co, Ni, Mn, Zn, Mg and Cu) of hexagonal ferrite is 30% or higher in X-ray diffraction and a peak value of a grain size distribution is in a range from 0.1 &mgr;m to 3 &mgr;m.
    Type: Grant
    Filed: February 14, 2002
    Date of Patent: June 15, 2004
    Assignee: TDK Corporation
    Inventors: Masami Endo, Atsuyuki Nakano
  • Patent number: 6736990
    Abstract: There can be provided an NiCuZn-based ferrite material containing an iron oxide, a copper oxide, zinc oxide and a nickel oxide in predetermined amounts as main components and a bismuth oxide, a silicon oxide, magnesium oxide and a cobalt oxide in predetermined amounts as additional components. Due to the predetermined amounts of the additional components, the ferrite material has an extremely good temperature characteristic (a change in permeability along with a change in temperature is small), a high quality coefficient Q and high strength.
    Type: Grant
    Filed: March 7, 2002
    Date of Patent: May 18, 2004
    Assignee: TDK Corporation
    Inventors: Takuya Aoki, Ko Ito, Bungo Sakurai, Yukio Takahashi, Tatsuya Shimazaki, Hidenobu Umeda, Akinori Ohi
  • Publication number: 20040051075
    Abstract: A magnetic ferrite composition including at least one of Mg, Ni, Cu, Zn, Mn, and Li and having a content of carbon within a predetermined range, for example, over 9.7 weight ppm to less than 96 weight ppm. The composition may be used as the magnetic core for an inductor, transformer, coil, etc. used for radios, televisions, communication devices, office automation equipment, switching power sources, and other electronic apparatuses or magnetic heads for video apparatuses or magnetic disk drives or other electronic components.
    Type: Application
    Filed: September 12, 2003
    Publication date: March 18, 2004
    Applicant: TDK Corporation
    Inventors: Takuya Aoki, Takeshi Nomura
  • Patent number: 6695972
    Abstract: This invention relates to the formula and preparation method for a multi-layer chip inductor material used in very high frequencies. The main composition of this material is planar hexagonal soft magnetic ferrite, and ingredient is low temperature sintering aid. Preparation method is a synthetic method of solid phase reaction. The sintering aid is prepared by secondary doping. By the process of ball grinding, drying, pre-calcining, ball grinding, drying, granulating, forming, sintering, and so forth, very high frequency inductor material of superior quality is obtained, realizing low temperature sintering under a temperature lower than 900° C. This invention is of low cost, high performance, suitable for multi-layer chip inductors at very high frequencies of 300M-800 MHz.
    Type: Grant
    Filed: January 14, 2002
    Date of Patent: February 24, 2004
    Assignees: Tsinghua Tongfang Co., Ltd., Tsinghua University
    Inventors: Xiaohui Wang, Longtu Li, Ji Zhou, Shuiyuan Su, Zhilun Gui, Zhenxing Yue, Zhenwei Ma, Li Zhang
  • Publication number: 20040031946
    Abstract: A Ni type ferrite material of a low magnetic loss. The Ni type ferrite material is formed by adding MnO2 in an amount of 0.1 to 10 mol % to a ferrite material of a composition containing Fe2O3 in 40 to 50 mol %, ZnO in 20 to 33 mol %, CuO in 2 to 10 mol %, and NiO in the remainder. Such Ni type ferrite material is adapted for use in a coil component as a core material because of a smaller magnetic loss in comparison with a prior material, and has a high electric resistance to allow direct coil winding on the core, thereby realizing reduction in both size and weight of the coil component.
    Type: Application
    Filed: May 23, 2003
    Publication date: February 19, 2004
    Inventors: Masayuki Inagaki, Yoshio Matsuo, Toshiaki Tomozawa
  • Patent number: 6689287
    Abstract: The subject invention includes a composite material comprising a ferroelectric material and a ferromagnetic material having a loss factor (tan &dgr;) for the composite material which includes a dielectric loss factor of the ferroelectric material and a magnetic loss factor of the ferromagnetic material. The composite material achieves the loss factor of from 0 to about 1.0 for a predetermined frequency range greater than 1 MHz. The ferroelectric material has a dielectric loss factor of from 0 to about 0.5 and the ferromagnetic material has a magnetic loss factor of from 0 to about 0.5 for the predetermined frequency range. The ferroelectric material is present in an amount from 10 to 90 parts by volume based on 100 parts by volume of the composite material and the ferromagnetic material is present in an amount from 10 to 90 parts by volume based upon 100 parts by volume of the composite material such that the amount of the ferroelectric material and the ferromagnetic material equals 100 parts by volume.
    Type: Grant
    Filed: November 1, 2001
    Date of Patent: February 10, 2004
    Assignee: Delphi Technologies, Inc.
    Inventors: Norman W. Schubring, Joseph V. Mantese, Adolph L. Micheli
  • Patent number: 6666991
    Abstract: A fluorescent or luminous composition, comprising a multilayered film-coated powder having at least two coating films on a base particle, and a fluorescent or luminous substance; the composition, wherein at least one layer of the coating films contains the fluorescent or luminous substance; a genuine/counterfeit discrimination object, in which the fluorescent or luminous composition; and a genuine/counterfeit discrimination method, comprising recognizing fluorescence or luminescence by irradiating, with a light, the genuine/counterfeit discrimination object.
    Type: Grant
    Filed: May 29, 2001
    Date of Patent: December 23, 2003
    Assignees: Nittetsu Mining Co., Ltd.
    Inventors: Takafumi Atarashi, Kiyoshi Hoshino, Katsuto Nakatsuka
  • Patent number: 6660179
    Abstract: There is provided a sintered body at least 80% of which is constituted of a Y-type hexagonal ferrite. The sintered body contains, as main components, a cobalt oxide, a copper oxide, an iron oxide and AO (AO is at least one of BaO or SrO) in predetermined amounts in mol %, more preferably contains MO (MO is at least one of NiO, ZnO or MgO) in a predetermined amount in mol % in addition to the above components, and also contains, as additional components, bismuth oxide (Bi2O3), borosilicate glass, borosilicate zinc glass or bismuth glass in predetermined amounts in wt %. Thus, a sintered body which exhibits good magnetic properties and is usable up to a high frequency band ranging from several hundred megahertz to gigahertz, contains as few hetero phases other than a Y-type hexagonal ferrite as possible and can be calcined at a temperature of not higher than 1,000° C., particularly about 900° C., and a high-frequency circuit component using the sintered body can be provided.
    Type: Grant
    Filed: March 12, 2002
    Date of Patent: December 9, 2003
    Assignee: TDK Corporation
    Inventors: Hidenobu Umeda, Taku Murase
  • Patent number: 6652768
    Abstract: A magnetic ferrite composition including at least one of Mg, Ni, Cu, Zn, Mn, and Li and having a content of carbon within a predetermined range, for example, over 9.7 weight ppm to less than 96 weight ppm. The composition may be used as the magnetic core for an inductor, transformer, coil, etc. used for radios, televisions, communication devices, office automation equipment, switching power sources, and other electronic apparatuses or magnetic heads for video apparatuses or magnetic disk drives or other electronic components.
    Type: Grant
    Filed: October 10, 2002
    Date of Patent: November 25, 2003
    Assignee: TDK Corporation
    Inventors: Takuya Aoki, Takeshi Nomura
  • Patent number: 6652767
    Abstract: In a composition for a plastic magnet, containing an Nd—Fe—B based alloy powder and a ferrite magnetic material powder mixed to a resin material, the Nd—Fe—B based alloy powder has particle sizes distributed in a range of 100 to 400 &mgr;m, and the ferrite magnetic material powder has an average particle size of approximately 1 &mgr;m. The weight ratio of the Nd—Fe—B based alloy powder to the ferrite magnetic material powder is in a range of 30:70 to 70:30. Further, the ratio of the total weight of the Nd—Fe—B based alloy powder 2 and the ferrite magnetic material powder 3 to the weight of the resin material is in a range of 90:10 to 80:20. Thus, in a plastic magnet 1 formed using the composition, peripheries of particles of the Nd—Fe—B based alloy powder 2 are surrounded by particles of the ferrite magnetic material powder 3 and the resin material.
    Type: Grant
    Filed: April 9, 2002
    Date of Patent: November 25, 2003
    Assignee: Enplas Corporation
    Inventor: Satoshi Kazamaturi
  • Patent number: 6645394
    Abstract: A high frequency magnetic material ceramic composition including materials having the general formula (Ca, A)zCuxB8−x−zO12 is prepared. A represents Y and/or at least one element selected from the rare earth elements excluding Y; B represents metal elements which are different from A and include at least Fe and V. x has a value of 0.002<x<0.2; and z is a value of 3.0<z≦3.09. The Ca/V ratio is 2.0<Ca/V≦2.4. A irreversible circuit component containing center electrodes electrically insulated from each other in a ferrite member made of the high frequency magnetic material ceramic is provided.
    Type: Grant
    Filed: May 17, 2002
    Date of Patent: November 11, 2003
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Yuko Fujita, Tatsuya Matsunaga
  • Patent number: 6569346
    Abstract: A ferrite with a high permeability and a high dielectric constant is introduced. Raw material powders, such as TiO2, Fe2O3 and the oxide of Mn, Ni, Cu, Mg, Li or Zn is prepared and combined in the proportion Tix(MFe2O4+2x/y)y, where x+y=1 and 0<×<1. M is any one of a mixture of metals selected from Mn, Ni, Cu, and Zn. The ratio between x and y can be adjusted according to practical needs to obtain ferrites with different permeabilities and dielectric constants. The ferrite can simultaneously be a magnetic material and a dielectric material in an electronic element. This can avoid the possible drawbacks due to sintering of two different materials in the prior art.
    Type: Grant
    Filed: December 28, 2001
    Date of Patent: May 27, 2003
    Assignee: Industrial Technology Research Institute
    Inventors: Mean-Jue Tung, Yu-Ting Huang, Yen-Ping Wang
  • Publication number: 20030085375
    Abstract: The subject invention includes a composite material comprising a ferroelectric material and a ferromagnetic material having a loss factor (tan &dgr;) for the composite material which includes a dielectric loss factor of the ferroelectric material and a magnetic loss factor of the ferromagnetic material. The composite material achieves the loss factor of from 0 to about 1.0 for a predetermined frequency range greater than 1 MHz. The ferroelectric material has a dielectric loss factor of from 0 to about 0.5 and the ferromagnetic material has a magnetic loss factor of from 0 to about 0.5 for the predetermined frequency range. The ferroelectric material is present in an amount from 10 to 90 parts by volume based on 100 parts by volume of the composite material and the ferromagnetic material is present in an amount from 10 to 90 parts by volume based upon 100 parts by volume of the composite material such that the amount of the ferroelectric material and the ferromagnetic material equals 100 parts by volume.
    Type: Application
    Filed: November 1, 2001
    Publication date: May 8, 2003
    Applicant: Delphi Technologies Inc.
    Inventors: Norman W. Schubring, Joseph V. Mantese, Adolph L. Micheli
  • Patent number: 6558566
    Abstract: Ni—Cu—Zn based oxide magnetic materials, in that not only the internal conductor is stabilized at very low firing temperatures, but also the characteristics in the high frequency zones of 100 MHz or higher are excellent. The oxide magnetic materials comprises, Fe2O3: 35.0 to 51.0 mol %, CuO: 1.0 to 35 mol %, NiO: 38.0 to 64.0 mol %, ZnO: 0 to 10.0 mol % (including 0%) and Ca: 0.3 wt % or lower (not including 0%), and, optionally, CoO: 0.7 wt % or lower.
    Type: Grant
    Filed: March 12, 2001
    Date of Patent: May 6, 2003
    Assignee: TDK Corporation
    Inventors: Takuya Ono, Ko Ito
  • Publication number: 20030052298
    Abstract: This invention relates to the formula and preparation method for a multi-layer chip inductor material used in very high frequencies. The main composition of this material is planar hexagonal soft magnetic ferrite, and ingredient is low temperature sintering aid. Preparation method is a synthetic method of solid phase reaction. The sintering aid is prepared by secondary doping. By the process of ball grinding, drying, pre-calcining, ball grinding, drying, granulating, forming, sintering, and so forth, very high frequency inductor material of superior quality is obtained, realizing low temperature sintering under a temperature lower than 900° C. This invention is of low cost, high performance, suitable for multi-layer chip inductors at very high frequencies of 300M-800 MHz.
    Type: Application
    Filed: January 14, 2002
    Publication date: March 20, 2003
    Applicant: Tsinghua Tongfang Co., Ltd.
    Inventors: Xiaohui Wang, Longtu Li, Ji Zhou, Shuiyuan Su, Zhilun Gui, Zhenxing Yue, Zhenwei Ma, Li Zhang
  • Publication number: 20030052299
    Abstract: There is provided a sintered body at least 80% of which is constituted of a Y-type hexagonal ferrite. The sintered body contains, as main components, a cobalt oxide, a copper oxide, an iron oxide and AO (AO is at least one of BaO or SrO) in predetermined amounts in mol %, more preferably contains MO (MO is at least one of NiO, ZnO or MgO) in a predetermined amount in mol % in addition to the above components, and also contains, as additional components, bismuth oxide (Bi2O3), borosilicate glass, borosilicate zinc glass or bismuth glass in predetermined amounts in wt %. Thus, a sintered body which exhibits good magnetic properties and is usable up to a high frequency band ranging from several hundred megahertz to gigahertz, contains as few hetero phases other than a Y-type hexagonal ferrite as possible and can be calcined at a temperature of not higher than 1,000° C., particularly about 900° C., and a high-frequency circuit component using the sintered body can be provided.
    Type: Application
    Filed: March 12, 2002
    Publication date: March 20, 2003
    Inventors: Hidenobu Umeda, Taku Murase
  • Publication number: 20030038273
    Abstract: A magnetic ferrite composition including at least one of Mg, Ni, Cu, Zn, Mn, and Li and having a content of carbon within a predetermined range, for example, over 9.7 weight ppm to less than 96 weight ppm. The composition may be used as the magnetic core for an inductor, transformer, coil, etc. used for radios, televisions, communication devices, office automation equipment, switching power sources, and other electronic apparatuses or magnetic heads for video apparatuses or magnetic disk drives or other electronic components.
    Type: Application
    Filed: October 10, 2002
    Publication date: February 27, 2003
    Applicant: TDK Corporation
    Inventors: Takuya Aoki, Takeshi Nomura
  • Publication number: 20030006394
    Abstract: A high frequency magnetic material ceramic composition including materials having the general formula (Ca, A)zCuxB8-x-zO12 is prepared. A represents Y and/or at least one element selected from the rare earth elements excluding Y; B represents metal elements which are different from A and include at least Fe and V. x has a value of 0.002<x<0.2; and z is a value of 3.0<z≦3.09. The Ca/V ratio is 2.0<Ca/V≦2.4. A irreversible circuit component containing center electrodes electrically insulated from each other in a ferrite member made of the high frequency magnetic material ceramic is provided.
    Type: Application
    Filed: May 17, 2002
    Publication date: January 9, 2003
    Inventors: Yuko Fujita, Tatsuya Matsunaga
  • Patent number: 6495059
    Abstract: A magnetic ferrite composition including at least one of Mg, Ni, Cu, Zn, Mn, and Li and having a content of carbon within a predetermined range, for example, over 9.7 weight ppm to less than 96 weight ppm. The composition may be used as the magnetic core for an inductor, transformer, coil, etc. used for radios, televisions, communication devices, office automation equipment, switching power sources, and other electronic apparatuses or magnetic heads for video apparatuses or magnetic disk drives or other electronic components.
    Type: Grant
    Filed: September 13, 2000
    Date of Patent: December 17, 2002
    Assignee: TDK Corporation
    Inventors: Takuya Aoki, Takeshi Nomura
  • Patent number: 6451220
    Abstract: A magnetic composition comprised of cobalt ferrite nanoparticles dispersed in an ionic exchange resin.
    Type: Grant
    Filed: January 21, 1997
    Date of Patent: September 17, 2002
    Assignee: Xerox Corporation
    Inventors: Ronald F. Ziolo, Javier Tejada Palacios, Elizabeth C. Kroll, Xixiang Zhang, Rachel Pieczynski
  • Patent number: 6440323
    Abstract: This invention provides a Mn—Zn ferrite which has a high electrical resistance and can sufficiently satisfy the use in a high frequency region exceeding 1 MHz. This invention further provides a production process of the Mn—Zn ferrite in which mixed powder whose components are adjusted so as to have a basic component composition containing 44.0 to 50.0 mol% Fe2O3, 4.0 to 26.5 mol % ZnO, 0.1 to 8.0 mol % one or two from TiO2 and SnO2 and the remainder consisting of MnO, and further to contain 0.01 to 2.00 mass % one or more of CoO, NiO, and MgO as additive is pressed, then sintered and cooled in the air or in an atmosphere containing some amount of oxygen.
    Type: Grant
    Filed: October 18, 2000
    Date of Patent: August 27, 2002
    Assignee: Minebea Co., Ltd.
    Inventors: Osamu Kobayashi, Osamu Yamada, Kiyoshi Ito
  • Patent number: 6436307
    Abstract: A ferrite material based on nickel, copper and zinc has the following formula: NixZnyCuzCo&egr;Fe2±&dgr;O4 in which: x+y+Z+&egr;=1±&dgr; &dgr;≦0.05 0.04≦&egr; 0.05≦z≦0.35 A material of this kind has the advantage of showing reduced losses.
    Type: Grant
    Filed: June 19, 2000
    Date of Patent: August 20, 2002
    Assignee: Thomson-CSF
    Inventors: Richard Lebourgeois, Jérôme Ageron, Jean-Charles Bremaud, Georges Peyresoubes, Jean-Pierre Joulain
  • Patent number: 6416682
    Abstract: The present invention relates to methods of producing synthetic crystals (typically minerals) or comparable inorganic compounds by reactions of metal salts and metal oxyhydroxides under near-critical, critical or supercritical solvent conditions, avoiding thereby many of the difficulties associated with conventional solid state or wet chemistry synthesis. The metal oxyhydroxides are typically divalent or trivalent metals and the preferred solvent is typically (but not exclusively) water under near-critical, critical or supercritical conditions. The crystals so produced have a controlled particle size distribution. The crystals produced by the present invention also have morphologies with favorable properties for compaction into green bodies for subsequent sintering into near-net-shapes, approaching maximum theoretical densities. Avoidance of noxious by-products is another advantage of the present synthetic methods.
    Type: Grant
    Filed: November 4, 1999
    Date of Patent: July 9, 2002
    Assignee: Ceramic Oxides International B.V.
    Inventors: Pieter Krijgsman, Daniel J. W. Ijdo
  • Patent number: 6416681
    Abstract: Granule for forming ferrite is provided by mixing powders of ferrite raw material, polyvinyl alcohol as a binder and polyethylene glycol added as plasticizer and having molecular weight being 1000 to 6000, and forming granules.
    Type: Grant
    Filed: August 23, 2000
    Date of Patent: July 9, 2002
    Assignee: TDK Corporation
    Inventor: Hiroshi Harada
  • Patent number: 6379579
    Abstract: Provided are a method for preparing an Ni—Cu—Zn ferrite powder having excellent sinterability at a lower temperature, and a method for producing a laminated chip inductor from the above ferrite powder. The method for preparing the ferrite powder is a method for the preparation of a soft magnetic ferrite powder composed of Fe, Ni, Cu and Zn as main components, and comprises the step of allowing an organic additive to be present in a slurry containing a calcined product of a starting powder and water, wherein the organic additive is an organic compound having a hydroxyl group and a carboxyl group or a neutralization salt or lactone thereof, or the organic additive is an organic compound having a hydroxymethylcarbonyl group, an organic compound having an enol type hydroxyl group dissociable as an acid or a salt thereof.
    Type: Grant
    Filed: March 7, 2000
    Date of Patent: April 30, 2002
    Assignee: TDK Corporation
    Inventor: Hiroshi Harada
  • Patent number: 6375862
    Abstract: The present invention can provide a MgCuZn-based ferrite sintered compact which is constituted by having as substantial main component compositions 7.5 to 23.0 mole % of magnesium oxide, 7.0 to 20.0 mole % of copper oxide, 19.0 to 24.2 mole % of zinc oxide and 48.5 to 50.3 mole % of ferric oxide, and the average particle diameter of the ferrite sintered compact is in a range of 1.10 to 7.30 &mgr;m while the standard deviation &sgr; of the size distribution is in a range of 0.60 to 10.00, resulting in the ferrite sintered compact which has a high impedance with a frequency of not less than 50 MHz and is capable of efficiently cutting of radiant noise by selecting inexpensive materials.
    Type: Grant
    Filed: September 18, 2000
    Date of Patent: April 23, 2002
    Assignee: TDK Corporation
    Inventors: Hidenobu Umeda, Taku Murase, Isao Kanada, Tatsuya Shimazaki
  • Publication number: 20010022354
    Abstract: To use a media agitating mill of a wet internal circulation type when grinding materials, and offer oxide magnetic materials and coils in which influences of ZrO2 and Y2O3 mixing when using partially stabilized zirconia as media beads are improved. The magnetic materials and coils are characterized in that Fe2O3, ZnO, NiO and CuO are main components, and Y2O3, ZrO2 and Bi2O3 are contained with respect to these main components, where an amount of Y2O3 is 0.007 to 0.028 wt % for the total amount, an amount of ZrO2 is 0.12 to 0.55 wt % therefor and an amount of Bi2O3 is 0.03 to 10.12 wt % for the same.
    Type: Application
    Filed: January 19, 2001
    Publication date: September 20, 2001
    Applicant: TDK CORPORATION
    Inventors: Ko Ito, Yukio Takahashi
  • Patent number: 6287479
    Abstract: Magnetic ceramic compositions include a Fe compound, a Zn compound, a Ni compound and a Cu compound as primary components, and also includes a bismuth compound and a cobalt compound as additive components. The primary component composition ratio (Fe2O3, ZnO, NiO+CuO) represented by molar percent of Fe2O3, ZnO, and (NiO and CuO), is in the region enclosed by point A (48.0, 0.5, 51.5), point B (48.0, 1.5, 50.5), point C (45.5, 4.0, 50.5), point D (44.0, 4.0, 52.0), and point E (44.0, 0.5, 55.5) in a ternary diagram. About 8.0 to 14.0 molar percent of the Cu compound is included in 100 molar percent of the primary components as Fe2O3, ZnO, NiO, and CuO. About 0.25 to 1.0 part by weight of the bismuth compound as Bi2O3 and about 0.25 to 3.0 parts by weight of the cobalt compound as Co3O4 with respect to 100 parts by weight of the primary components are included.
    Type: Grant
    Filed: February 22, 2000
    Date of Patent: September 11, 2001
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Hiromi Tanaka
  • Patent number: 6264875
    Abstract: The present invention relates to a method for preparing multi-purpose magnetized and sintered ceramics, comprising the steps of adding water to a mixture of Maek-Ban Stone and soft sericite, stirring and maturing at a room temperature, sintering, and irradiating with a magnetic field. The ceramics obtained by the present invention produce various effects such as keeping food fresh, deodorization and purification.
    Type: Grant
    Filed: December 14, 1999
    Date of Patent: July 24, 2001
    Inventor: Sang-Yool Pyun
  • Patent number: 6251299
    Abstract: Magnetic material has a ceramics having a composition in the range of Fe2O3 35.0 to 44.5 mol %, NiO 47.0 to 56.5 mol % and CuO 5.0 to 12.0 mol %, and the ceramics having relative magnetic permeability of 15 or less, and composes the inductance element comprising this magnetic material and the internal metallic conductor. For making laminated inductance elements by concurrently baking ceramic green sheets and internal metallic conductors, substances to be used as ceramic green sheets, which substances have the composition in the above mentioned range are used, and a silver or silver alloys are used as the internal metallic conductor, and the calcination is carried out at temperature of 880 to 920° C.
    Type: Grant
    Filed: December 22, 1999
    Date of Patent: June 26, 2001
    Assignee: TDK Corporation
    Inventors: Takashi Ito, Yukio Takahashi, Fumio Uchikoba
  • Patent number: 6210597
    Abstract: Since the radio wave absorbent of the present invention has the main component of a magnesium-zinc system ferrite material containing 45 to 50 mol % of iron oxide, 7 to 19.7 mol % of magnesium oxide, 24 to 28.5 mol % of zinc oxide, 4 to 16 mol % of copper oxide, and 0.1 to 6 mol % of manganese oxide, a matching thickness is less than 8 mm, and the total weight of the radio wave absorbent for use in the inner wall of a radio wave dark room or the outer wall of a building or the like is remarkably reduced as compared with the radio wave absorbent obtained by sintering the conventional magnesium-zinc system ferrite material. Moreover, since the radio wave absorbent can be obtained by sintering the material at a relatively low sintering temperature of about 950 to 1150° C., the manufacture cost can be reduced relative to the radio wave absorbent obtained by sintering the conventional nickel-zinc system ferrite material.
    Type: Grant
    Filed: May 21, 1999
    Date of Patent: April 3, 2001
    Assignee: TDK Corporation
    Inventors: Taku Murase, Masatsugu Morita, Naoyoshi Sato
  • Patent number: 6210596
    Abstract: A magnetic ceramic composition containing ferrite serving as a primary component and a sintering aid. The composition can be sintered at low temperature. The sintering aid contains about 2-45 mol % Li2O; about 5-40 mol % RO, with R being at least one of Ba, Sr, Ca, and Mg; and about 30-70 mol % (Ti, Si)O2 with SiO2 accounting for at least about 15 mol %. The resultant composition provides inductor elements in which migration of inner conductors is suppressed, and insulation deterioration and increase of direct-current resistance is restrained.
    Type: Grant
    Filed: December 23, 1998
    Date of Patent: April 3, 2001
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Kazuhiko Takenaka, Tatsuru Takaoka
  • Patent number: 6200493
    Abstract: There is disclosed an MnMgCuZn ferrite material which contains ranges of 46.5 to 50.4 mol % of iron oxide, 10.5 to 22.0 mol % of magnesium oxide, 22.5 to 25.0 mol % of zinc oxide, 6.0 to 16.0 mol % of copper oxide, and 0.1 to 3.5 mol % of manganese oxide. Advantages of an MnMgCuZn ferrite material that resistivity is relatively high and material cost is low are utilized to realize a superior MnMgCuZn ferrite material which is much smaller in magnetic loss than conventional materials of the same series and which has a sufficient saturated magnetic flux density.
    Type: Grant
    Filed: March 18, 1999
    Date of Patent: March 13, 2001
    Assignee: TDK Corporation
    Inventors: Taku Murase, Takuya Aoki, Naoyoshi Sato, Isao Kanada
  • Patent number: 6187218
    Abstract: A method of producing a Ni—Cu—Zn ferrite material comprises the steps of preparing a mixture of an iron compound powder having a specific surface area of about 8.5 m2/g or more, a nickel compound powder, copper compound powder and a zinc compound powder, the mixture having a specific surface area of about 8.0 m2/g or more; pre-calcining the mixture such that the pre-calcined mixture has a surface area of about 5.0 m2/g or more and a spinel crystal synthesizability within a range of about 80.5% to 98%; and milling the pre-calcined mixture to obtain a powder of a Ni—Cu—Zn ferrite material having a specific surface area of about 6.0 m2/g or more.
    Type: Grant
    Filed: September 29, 1999
    Date of Patent: February 13, 2001
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Takashi Kodama, Hideo Ajichi, Takehiro Konoike, Kunisaburo Tomono