With Group Ii Metal Or Lead Patents (Class 252/62.62)
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Patent number: 6994797Abstract: A ferrite magnet obtained by adding at least one element selected from the group consisting of Co, Ni, Mn and Zn to a ferrite having a hexagonal M-type magnetoplumbite structure, in which a portion of Sr, Ba, Pb or Ca is replaced with at least one element that is selected from the group consisting of the rare-earth elements (including Y) and Bi and that always includes La, during the fine pulverization process thereof, and then subjecting the mixture to re-calcining and/or sintering process(es). By adding a small amount of the element such as Co, Ni, Mn or Zn to the ferrite already having the hexagonal M-type magnetoplumbite structure during the fine pulverization process thereof, the magnetic properties can be improved.Type: GrantFiled: February 6, 2002Date of Patent: February 7, 2006Assignee: Neomax Co., Ltd.Inventors: Etsushi Oda, Sachio Toyota, Seiichi Hosokawa
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Patent number: 6991742Abstract: A Mn—Zn ferrite and a coil component are provided which obtains a low core loss in a frequency band above 1 MHz and even above 5 MHz and which can duly function in such a high frequency band. The Mn—Zn contains as basic components 44.00 to 50.0 mol % Fe2O3 (50 mol % excluded), 4.0 to 26.5 mol % ZnO, and remainder MnO, and has a dielectric loss tan ? of 0.3 or less at 1 kHz, and a complex relative permittivity ? of 1,000 or less at 1 MHz, whereby a core loss decreases in the high frequency band.Type: GrantFiled: August 8, 2002Date of Patent: January 31, 2006Assignee: Minebea Co., Ltd.Inventors: Kiyoshi Ito, Osamu Kobayashi, Yukio Suzuki
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Patent number: 6984337Abstract: An Mn—Zn ferrite includes base components of 44.0 to 49.8 mol % Fe2O3, 4.0 to 26.5 mol % ZnO, at least one of 0.1 to 4.0 mol % TiO2 and SnO2, 0.5 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 mol % Fe2O3 and a limited amount (0.5 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. And, since an appropriate amount of TiO2 and/or SnO2 is contained, an initial permeability is kept adequately high, whereby an excellent soft magnetism can be achieved in a high frequency band such as 1 MHz.Type: GrantFiled: January 28, 2004Date of Patent: January 10, 2006Assignee: Minebea Co., Ltd.Inventors: Osamu Kobayashi, Osamu Yamada, Kiyoshi Ito
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Patent number: 6984338Abstract: 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: GrantFiled: January 28, 2004Date of Patent: January 10, 2006Assignee: Minebea Co., Ltd.Inventors: Osamu Kobayashi, Osamu Yamada, Kiyoshi Ito
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Patent number: 6955768Abstract: A ferrite magnet obtained by adding a ferrite having a spinel-type structure to a ferrite having a hexagonal M-type magnetoplumbite structure, in which a portion of Sr, Ba, Pb or Ca is replaced with at least one element that is selected from the group consisting of the rare-earth elements (including Y) and Bi and that always includes La, during the fine pulverization process thereof. By adding a small amount of the element such as Co, Ni, Mn or Zn to the ferrite already having the hexagonal M-type magnetoplumbite structure during the fine pulverization process thereof, the magnetic properties can be improved.Type: GrantFiled: February 6, 2002Date of Patent: October 18, 2005Assignee: Neomax Co., Ltd.Inventors: Etsushi Oda, Seiichi Hosokawa, Sachio Toyota
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Patent number: 6940381Abstract: 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: GrantFiled: December 11, 2003Date of Patent: September 6, 2005Assignee: TDK CorporationInventors: Masahiko Watanabe, Katsushi Yasuhara
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Patent number: 6929758Abstract: A ferrite magnet obtained by adding either an oxide of Mn or oxides of Mn and Co to a ferrite having a hexagonal M-type magnetoplumbite structure, in which a portion of Sr, Ba, Pb or Ca is replaced with at least one element that is selected from the group consisting of the rare earth elements (including Y) and Bi and that always includes La, during the fine pulverization process thereof, and then subjecting the mixture to re-calcining and/or sintering process(es). By adding a small amount of the element Mn or elements Mn and Co to the ferrite already having the hexagonal M-type magnetoplumbite structure during the fine pulverization process thereof, the magnetic properties can be improved.Type: GrantFiled: December 6, 2001Date of Patent: August 16, 2005Assignee: Neomax Co., Ltd.Inventors: Etsushi Oda, Sachio Toyota, Seiichi Hosokawa
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Patent number: 6929757Abstract: A magnetorheological fluid containing magnetorheological particles which are resistant to oxidation having regions rich in diffused nitrogen located therein and a method for producing such magnetorheological fluid.Type: GrantFiled: August 25, 2003Date of Patent: August 16, 2005Assignee: General Motors CorporationInventors: John C. Ulicny, Yang T. Cheng
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Patent number: 6908568Abstract: 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: GrantFiled: June 17, 2002Date of Patent: June 21, 2005Assignee: TDK CorporationInventors: Kiyoyuki Masuzawa, Hitoshi Taguchi
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Patent number: 6905629Abstract: An Mn—Zn ferrite wherein 0 to 5000 ppm of a Co oxide in a Co3O4 conversion is contained in a basic component constituted by Fe2O3: 51.5 to 57.0 mol % and ZnO: 0 to 15 mol % (note that 0 is not included) wherein the rest is substantially constituted by MnO; and a value ? in a formula (1) below in said ferrite satisfies ??0.93. ?=((Fe2+?Mn3+?Co3+)×(4.29×A+1.91×B+2.19×C+2.01×D))/((A?B?C?D)×100)??formula (1). Note that in the formula (1), (Fe2+?Mn3+?Co3+): [wt %], A: Fe2O3 [mol %], B: MnO [mol %], C: ZnO [mol %] and D: CoO [mol %]. According to the present invention, a highly reliable Mn—Zn ferrite used as a magnetic core of a power supply transformer, etc. of a switching power supply, etc., having a small core loss in a wide temperature range, furthermore, exhibiting a little deterioration of core loss characteristics under a high temperature (in a high temperature storage test) and having excellent magnetic stability, a transformer magnetic core and a transformer can be provided.Type: GrantFiled: August 29, 2003Date of Patent: June 14, 2005Assignee: TDK CorporationInventors: Yuji Sezai, Katsushi Yasuhara, Kenya Takagawa, Masahiko Watanabe
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Patent number: 6902685Abstract: A ferrite magnet powder and a ferrite magnet exhibiting improved magnetic properties are provided at a reduced manufacturing cost. An application product and manufacturing methods thereof are also provided. An oxide magnetic material includes, as a main phase, a ferrite having a hexagonal M-type magnetoplumbite structure. The material includes: A, which is at least one element selected from the group consisting of Sr, Ba, Pb and Ca; R, which is at least one element selected from the group consisting of Y (yttrium), the rare earth elements and Bi; Fe; and B (boron). The constituents A, R, Fe and B of the material satisfy the inequalities of 7.04 at %?A?8.68 at %, 0.07 at %?R?0.44 at %, 90.4 at %?Fe?92.5 at % and 0.015 at %?B?0.87 at % to the sum of the elements A, R, Fe and B.Type: GrantFiled: May 21, 2002Date of Patent: June 7, 2005Assignee: Neomax Co., Ltd.Inventors: Sachio Toyota, Isamu Furuchi, Yoshinori Kobayashi
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Patent number: 6893581Abstract: 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: GrantFiled: January 28, 2003Date of Patent: May 17, 2005Assignee: Sanyo Electric Co., Ltd.Inventors: Takashi Umemoto, Hideki Yoshikawa, Keiichi Kuramoto, Hitoshi Hirano
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Patent number: 6872325Abstract: 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: GrantFiled: September 9, 2002Date of Patent: March 29, 2005Assignee: General Electric CompanyInventors: Krisanu Bandyopadhyay, Kunj Tandon, Amit Chakrabarti
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Patent number: 6872251Abstract: 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: GrantFiled: May 29, 2002Date of Patent: March 29, 2005Assignee: TDK CorporationInventors: Minoru Takaya, Yoshiaki Akachi, Hiroyuki Uematsu, Hisashi Kobuke
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Patent number: 6858155Abstract: Ferrite materials, methods of forming the same, and products formed therefrom are disclosed, comprising, as main components, an iron oxide ranging from 55.5 to 58.0 mole percent calculated as Fe2O3, an amount of manganese oxide ranging from 38.0 to 41.0 mole percent calculated as MnO, and an amount of zinc oxide ranging from 3.3 to 4.7 mole percent calculated as ZnO. The present invention also includes, as minor components, an amount of calcium oxide ranging from 0.030 to 0.100 weight percent calculated as CaO, an amount of silicon oxide ranging from 0.015 to 0.040 weight percent calculated as SiO2, and an amount of niobium oxide ranging from 0.010 to 0.030 weight percent calculated as Nb2O5.Type: GrantFiled: December 12, 2001Date of Patent: February 22, 2005Assignee: Spang & CompanyInventors: Mark A. Fanton, Joseph F. Huth, III
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Patent number: 6852245Abstract: A composition for producing granules for molding ferrite, which comprises a ferrite slurry at least having raw ferrite powders; an ethylene-modified polyvinyl alcohol whose ethylene modified amount is from 4 to 10 mol %, average polymerization degree is from 500 to 1700, and average saponification degree is from 90.0 to 99.5 mol %; and water mixed therewith, ferrite granules produced from the composition, ferrite green body produced from the granules and ferrite sintered body produced from the sintered body are disclosed.Type: GrantFiled: April 26, 2002Date of Patent: February 8, 2005Assignee: TDK CorporationInventor: Hiroshi Harada
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Publication number: 20040229151Abstract: 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: ApplicationFiled: February 6, 2004Publication date: November 18, 2004Applicant: POWDERTECH CO., LTD.Inventors: Hiromichi Kobayashi, Issei Shinmura, Tsuyoshi Itagoshi, Yuji Sato
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Patent number: 6815063Abstract: There is disclosed a magnetic fluid medium which comprises a plurality of ferro- or ferri-magnetic particles, each of which particles has a largest dimension no greater than 100 nm, said particles having been prepared by a process which includes a step in which the particles are formed within an organic macromolecular shell.Type: GrantFiled: May 24, 2002Date of Patent: November 9, 2004Assignee: NanoMagnetics, Ltd.Inventor: Eric Mayes
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Patent number: 6814883Abstract: 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: GrantFiled: August 27, 2002Date of Patent: November 9, 2004Assignee: Murata Manufacturing Co., Ltd.Inventor: Hiroshi Marusawa
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Patent number: 6811718Abstract: In the method for manufacturing ferrite type permanent magnets according to the formula M1-xRxFe12-yTyO19: a) a mixture of the raw materials PM, PF, PR and PT of elements M, Fe, R and T, respectively, is formed, Fe and M being the main raw materials and R and T being substitute raw materials; b) the mixture is roasted to form a clinker; c) wet grinding of said clinker is carried out; d) the particles are concentrated and compressed in an orientation magnetic field to form an anisotropic, easy to handle green compact of a predetermined shape; and e) the anisotropic green compact D is sintered to obtain a sintered element. The surface are GS and percentage of at least one of the substitute raw materials is selected according to the surface area and percentage of the iron raw material to obtain magnets with high squareness and overall performance index properties.Type: GrantFiled: April 9, 2002Date of Patent: November 2, 2004Assignee: Ugimag SAInventors: Antoine Morel, Philippe Tenaud
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Patent number: 6800215Abstract: 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: GrantFiled: May 23, 2003Date of Patent: October 5, 2004Assignee: FDK CorporationInventors: Masayuki Inagaki, Yoshio Matsuo, Toshiaki Tomozawa
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Publication number: 20040183049Abstract: 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: ApplicationFiled: January 28, 2004Publication date: September 23, 2004Applicant: Minebea Co., Ltd.Inventors: Osamu Kobayashi, Osamu Yamada, Kiyoshi Ito
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Publication number: 20040185366Abstract: Disclosed is a carrier core material for an electrophotographic developing agent, which comprises 100 parts by weight of a ferrite component represented by a formula (A) and 0.1 to 5.0 parts by weight of ZrO2 that is present in the ferrite component without forming a solid solution, and which has a magnetization, at 1000(103/4&pgr;·A/m), of 65 to 85 Am2/kg and an electrical resistance, at an applied voltage of 1000 V, of 105 to 109 &OHgr;.Type: ApplicationFiled: February 6, 2004Publication date: September 23, 2004Inventors: Issei Shinmura, Hiromichi Kobayashi, Tsuyoshi Itagoshi, Yuji Sato
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Patent number: 6790379Abstract: 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: GrantFiled: September 12, 2003Date of Patent: September 14, 2004Assignee: TDK CorporationInventors: Takuya Aoki, Takeshi Nomura
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Publication number: 20040164269Abstract: 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: ApplicationFiled: February 25, 2003Publication date: August 26, 2004Inventor: Chaby Hsu
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Patent number: 6780555Abstract: 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: GrantFiled: January 22, 2002Date of Patent: August 24, 2004Assignee: Toda Kogyo CorporationInventors: Naoki Uchida, Minoru Kouzawa, Hiromitsu Misawa, Koso Aoki, Suehiko Miura
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Patent number: 6773619Abstract: An Mn—Zn based ferrite composition having a main component comprised of Fe2O3: 51.5 to 54.5 mol %, ZnO: 19.0 to 27.0 mol % and the rest of substantially MnO and a first sub component comprised of 0.002 to 0.040 wt % of SiO2, 0.003 to 0.045 wt % of CaO and 0.010 wt % or less of P with respect to 100 wt % of the main component. In a magnetic core for a transformer comprised of this composition, the THD of the transformer becomes −84 dB or less in a broad frequency band, so it can be preferably used as a magnetic core, for example, for an xDSL modem transformer.Type: GrantFiled: July 12, 2002Date of Patent: August 10, 2004Assignee: TDK CorporationInventors: Yuji Sezai, Ippou Hirai, Masahiko Watanabe
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Patent number: 6767478Abstract: 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: GrantFiled: August 2, 2002Date of Patent: July 27, 2004Assignee: Minebea Co., Ltd.Inventors: Kiyoshi Ito, Osamu Kobayashi, Yukio Suzuki
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Patent number: 6761830Abstract: A method for manufacturing type M hexaferrite powders fo the formula AFe12O19 where A is Ba, Sr, Ca, Pb or a mixture thereof. An iron oxide Fe2O3 and a compound A are mixed with a molar ratio n=Fe2O3/AO, formed and calcined, and the agglomerates which result from the calcining are ground to obtain a fine ferrite powder. The mixture is formed with a ratio n ranging between 5.7 and 6.1, and with a predetermined degree of homogeneity, and before or during the grinding process, an agent controlling the microstructure is introduced.Type: GrantFiled: February 15, 2002Date of Patent: July 13, 2004Assignee: Ugimag S.A.Inventors: Antoine Morel, Eric Brando, Philippe Tenaud
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Patent number: 6752932Abstract: A ferrite core is provided. This ferrite core has high saturation flux density Bs at a high temperature of 100° C. or higher, and in particular, at around 150° C., and has excellent magnetic stability at a high temperature, experiencing reduced deterioration of magnetic properties, and in particular, reduced core loss at such high temperature (even by trading off some improvement in the level of the loss).Type: GrantFiled: August 19, 2002Date of Patent: June 22, 2004Assignee: TDK CorporationInventors: Shigetoshi Ishida, Masahiko Watanabe, Katsushi Yasuhara
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Publication number: 20040116278Abstract: The present invention provides a method for producing a new catalyst of high polymerization activity for homo- or co-polymerization of ethylene, or more particularly a method for producing a titanium solid complex catalyst supported on a carrier containing magnesium, wherein said catalyst is capable of producing polymers of high bulk density and narrow particle size distribution with few fine particles.Type: ApplicationFiled: October 20, 2003Publication date: June 17, 2004Inventors: Chun-Byung Yang, Won-Young Kim, Weon Lee
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Patent number: 6736990Abstract: 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: GrantFiled: March 7, 2002Date of Patent: May 18, 2004Assignee: TDK CorporationInventors: Takuya Aoki, Ko Ito, Bungo Sakurai, Yukio Takahashi, Tatsuya Shimazaki, Hidenobu Umeda, Akinori Ohi
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Publication number: 20040061090Abstract: A ferrite magnet obtained by adding a ferrite having a spinel-type structure to a ferrite having a hexagonal M-type magnetoplumbite structure, in which a portion of Sr, Ba, Pb or Ca is replaced with at least one element that is selected from the group consisting of the rare-earth elements (including Y) and Bi and that always includes La, during the fine pulverization process thereof. By adding a small amount of the element such as Co, Ni, Mn or Zn to the ferrite already having the hexagonal M-type magnetoplumbite structure during the fine pulverization process thereof, the magnetic properties can be improved.Type: ApplicationFiled: July 22, 2003Publication date: April 1, 2004Inventors: Etsushi Oda, Seiichi Hosokawa, Sachio Toyota
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Publication number: 20040051075Abstract: 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: ApplicationFiled: September 12, 2003Publication date: March 18, 2004Applicant: TDK CorporationInventors: Takuya Aoki, Takeshi Nomura
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Patent number: 6695972Abstract: 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: GrantFiled: January 14, 2002Date of Patent: February 24, 2004Assignees: Tsinghua Tongfang Co., Ltd., Tsinghua UniversityInventors: Xiaohui Wang, Longtu Li, Ji Zhou, Shuiyuan Su, Zhilun Gui, Zhenxing Yue, Zhenwei Ma, Li Zhang
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Publication number: 20040031946Abstract: 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: ApplicationFiled: May 23, 2003Publication date: February 19, 2004Inventors: Masayuki Inagaki, Yoshio Matsuo, Toshiaki Tomozawa
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Publication number: 20040026654Abstract: A ferrite magnet powder and a ferrite magnet exhibiting improved magnetic properties are provided at a reduced manufacturing cost. An application product and manufacturing methods thereof are also provided. An oxide magnetic material includes, as a main phase, a ferrite having a hexagonal M-type magnetoplumbite structure. The material includes: A, which is at least one element selected from the group consisting of Sr, Ba, Pb and Ca; R, which is at least one element selected from the group consisting of Y (yttrium), the rare earth elements and Bi; Fe; and B (boron). The constituents A, R, Fe and B of the material satisfy the inequalities of 7.04 at %≦A=8.68 at %, 0.07 at %≦R≦0.44 at %, 90.4 at %≦Fe≦92.5 at % and 0.015 at %≦B≦0.87 at % to the sum of the elements A, R, Fe and B.Type: ApplicationFiled: March 24, 2003Publication date: February 12, 2004Inventors: Sachio Toyota, Isamu Furuchi, Yoshinori Kobayashi
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Patent number: 6689287Abstract: 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: GrantFiled: November 1, 2001Date of Patent: February 10, 2004Assignee: Delphi Technologies, Inc.Inventors: Norman W. Schubring, Joseph V. Mantese, Adolph L. Micheli
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Publication number: 20030235689Abstract: The present invention is directed to hexagonal ferrite particles coated with a dispersant and having an exceptionally uniform particle size distribution that makes them particularly useful in the manufacture of high density magnetic tape.Type: ApplicationFiled: May 29, 2003Publication date: December 25, 2003Inventors: William Rafaniello, Pete C. LeBaron, Melinda H. Keefe, Promod Kumar, Eric J. Swedburg
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Patent number: 6666991Abstract: 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: GrantFiled: May 29, 2001Date of Patent: December 23, 2003Assignees: Nittetsu Mining Co., Ltd.Inventors: Takafumi Atarashi, Kiyoshi Hoshino, Katsuto Nakatsuka
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Patent number: 6652767Abstract: 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: GrantFiled: April 9, 2002Date of Patent: November 25, 2003Assignee: Enplas CorporationInventor: Satoshi Kazamaturi
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Patent number: 6652768Abstract: 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: GrantFiled: October 10, 2002Date of Patent: November 25, 2003Assignee: TDK CorporationInventors: Takuya Aoki, Takeshi Nomura
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Patent number: 6650068Abstract: The induction coil core used for an induction coil of a discharge lamp, the discharge lamp including: a bulb containing discharge gas inside; and the induction coil for generating an electromagnetic field with a frequency in a range of 50 kHz to 1 MHz inclusive in the bulb. The core is made of a Mn—Zn polycrystalline ferrite and has a Curie temperature of 270° C. or more.Type: GrantFiled: March 2, 2001Date of Patent: November 18, 2003Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Toshiaki Kurachi, Koji Miyazaki, Katsushi Seki, Mamoru Takeda
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Patent number: 6627103Abstract: The invention provides a manganese-zinc ferrite production process comprising a maximum temperature holding step for firing and a cooling step in a nitrogen atmosphere. The nitrogen atmosphere changeover temperature T in the cooling step is below 1,1500° C. and equal to or higher than 1,0000° C., and the cooling rate V1 conforms to the condition defined by: T≦(V1+1,450)/1.5 (1) Here T is the nitrogen atmosphere changeover temperature in ° C. and V1 is the cooling rate in ° C./hour from T down to 900° C.Type: GrantFiled: March 16, 2001Date of Patent: September 30, 2003Assignee: TDK CorporationInventors: Katsushi Yasuhara, Kenya Takagawa
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Patent number: 6623879Abstract: Soft-magnetic hexagonal ferrite composite particles composed of 100 parts by weight of soft-magnetic hexagonal ferrite particles containing a Z-type ferrite, Y-type ferrite or W-type ferrite as a main phase, 0.3 to 10 parts by weight of barium carbonate particles, strontium carbonate particles or their mixture and 0.1 to 5 parts by weight of silicon dioxide particles.Type: GrantFiled: April 5, 2002Date of Patent: September 23, 2003Assignee: Toda Kogyo CorporationInventors: Yoji Okano, Takayuki Yoshida, Norio Sugita
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Publication number: 20030116746Abstract: An Mn-Zn based ferrite composition having a main component comprised of Fe2O3: 51.5 to 54.5 mol %, ZnO: 19.0 to 27.0 mol % and the rest of substantially MnO and a first sub component comprised of 0.002 to 0.040 wt % of Sio2, 0.003 to 0.045 wt % of CaO and 0.010 wt % or less of P with respect to 100 wt % of the main component. In a magnetic core for a transformer comprised of this composition, the THD of the transformer becomes −84 dB or less in a broad frequency band, so it can be preferably used as a magnetic core, for example, for an XDSL modem transformer.Type: ApplicationFiled: July 12, 2002Publication date: June 26, 2003Applicant: TDK CorporationInventors: Yuji Sezai, Ippou Hirai, Masahiko Watanabe
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Patent number: 6583699Abstract: A magnetic material includes main components having Fe2O3 of 46.0 to 51.0 mol %, CuO of 0.5 to 15.0 mol % and the rest being NiO. With respect to the main components of 100 wt parts, additives are added. The additives are bismuth oxide of 4.0 to 10.0 wt part in terms of Bi2O3, magnesium oxide of 1.0 to 5.0 wt part in terms of MgO, silicon oxide of 2.0 to 8.0 wt part in terms of SiO2, and cobalt oxide of 0.2 to 0.5 wt part in terms of CoO. Further, an inductor has a core including the above magnetic material, and is composed by molding a resin.Type: GrantFiled: October 29, 2001Date of Patent: June 24, 2003Assignee: TDK CorporationInventor: Ryo Yokoyama
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Patent number: 6569346Abstract: 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: GrantFiled: December 28, 2001Date of Patent: May 27, 2003Assignee: Industrial Technology Research InstituteInventors: Mean-Jue Tung, Yu-Ting Huang, Yen-Ping Wang
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Publication number: 20030085375Abstract: 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: ApplicationFiled: November 1, 2001Publication date: May 8, 2003Applicant: Delphi Technologies Inc.Inventors: Norman W. Schubring, Joseph V. Mantese, Adolph L. Micheli
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Patent number: 6558566Abstract: 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: GrantFiled: March 12, 2001Date of Patent: May 6, 2003Assignee: TDK CorporationInventors: Takuya Ono, Ko Ito