Using Organic Binder Or Organometallic Patents (Class 264/612)
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Patent number: 9281107Abstract: There are provided a rare-earth permanent magnet and a manufacturing method thereof capable of preventing deterioration of magnet properties. In the method, magnet material is milled into magnet powder. Next, a mixture is prepared by mixing the magnet powder and a binder made of long-chain hydrocarbon and/or of a polymer or a copolymer consisting of monomers having no oxygen atoms. Next, the mixture is formed into a sheet-like shape so as to obtain a green sheet. After that, the green sheet is held for a predetermined length of time at binder decomposition temperature in a non-oxidizing atmosphere so as to remove the binder by causing depolymerization reaction or the like to the binder, which turns into monomer. The green sheet from which the binder has been removed is sintered by raising temperature up to sintering temperature. Thereby a permanent magnet 1 is obtained.Type: GrantFiled: March 15, 2012Date of Patent: March 8, 2016Assignee: NITTO DENKO CORPORATIONInventors: Keisuke Taihaku, Katsuya Kume, Toshiaki Okuno, Izumi Ozeki, Tomohiro Omure, Takashi Ozaki
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Patent number: 8563620Abstract: The process for the synthesis of a silica monolith comprises the following steps: hydrolysis of a silicon alkoxide in order to form a hydrolysis precursor followed by a condensation of said hydrolysis precursor in the presence of an organic solvent, in the presence of water and of a basic catalyst in order to form oligomeric clusters containing several silicon atoms; dispersion of said oligomeric clusters in a solution in order to form a sol; polymerization of the sol in order to obtain a gel via a first heat treatment, at a temperature below the boiling point of the constituents of the sol; drying of the gel via a second heat treatment; conversion of the gel to a xerogel via a third heat treatment; dehydration and densification of the xerogel until the silica monolith is obtained via a fourth heat treatment.Type: GrantFiled: October 1, 2009Date of Patent: October 22, 2013Assignees: Universite des Sciences et Technologies de Lille, Centre National de la Recherche Scientifique (CNRS)Inventors: Mohamed Bouazaoui, Bruno Capoen, Hicham El-Hamzaoui, Laurent Bigot, Géraud Bouwmans
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Publication number: 20130141195Abstract: There are provided a rare-earth permanent magnet and a manufacturing method thereof capable of preventing deterioration of magnet properties. In the method, magnet material is milled into magnet powder. Next, a mixture is prepared by mixing the magnet powder and a binder made of a fatty acid methyl ester and/or one of or a blend of polymers and copolymers each composed of monomers satisfying a given condition. Next, the mixture is formed into a sheet-like shape to obtain a green sheet. After that, the green sheet is held for a predetermined length of time at binder decomposition temperature in a non-oxidizing atmosphere so as to remove the binder by causing depolymerization reaction or the like to the binder, which turns into monomer. The green sheet from which the binder has been removed is sintered by raising temperature up to sintering temperature. Thereby a permanent magnet 1 is obtained.Type: ApplicationFiled: March 15, 2012Publication date: June 6, 2013Applicant: NITTO DENKO CORPORATIONInventors: Keisuke Taihaku, Katsuya Kume, Izumi Ozeki, Toshiaki Okuno, Tomohiro Omure, Takashi Ozaki
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Publication number: 20130015394Abstract: A ferromagnetic powder composition including soft magnetic iron-based core particles, wherein the surface of the core particles is provided with at least one phosphorus-based inorganic insulating layer and then at least partially covered with metal-organic compound(s), wherein the total amount of metal-organic compound(s) is between 0.005 and 0.05% by weight of the powder composition, and wherein the powder composition further includes a lubricant. Further, a process for producing the composition and a method for the manufacturing of soft magnetic composite components prepared from the composition, as well as the obtained component.Type: ApplicationFiled: February 9, 2011Publication date: January 17, 2013Applicant: HÖGANÄS ABInventors: Björn Skårman, Zhou Ye
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Publication number: 20120248913Abstract: A ferrite sintered magnet has a surface roughness Rz of 3.5 ?m or less. A method for producing a ferrite sintered magnet includes: mixing magnetic powders with at least a binder resin to obtain a magnetic powder mixture; injection molding the magnetic powder mixture inside of a mold having a surface roughness of a surface in contact with the magnetic powder mixture of 2.0 ?m or less with a magnetic field applied to the mold, to obtain a molded body; and sintering the molded body.Type: ApplicationFiled: March 27, 2012Publication date: October 4, 2012Applicant: TDK CORPORATIONInventors: Hideyuki UMEZAWA, Yoshihiko MINACHI, Osanori MIZONOUE
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Publication number: 20120229245Abstract: Provided is a soft magnetic powder used for obtaining a dust core having a low hysteresis loss, in particular, in a high temperature range. A soft magnetic powder includes an aggregate of composite magnetic particles, each including a soft magnetic particle containing Fe, Si, and Al, and an insulating coating film disposed on the surface thereof, and satisfies the expressions (1) and (2) below: Expression (1) . . . 27?2.5a+b?29 and Expression (2) . . . 6?b?9, where a represents the Si content (mass %) and b represents the Al content (mass %). The soft magnetic powder is capable of reducing the hysteresis loss, in a high-temperature environment, of a dust core obtained using the soft magnetic powder.Type: ApplicationFiled: May 17, 2011Publication date: September 13, 2012Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTDInventors: Asako Watanabe, Toru Maeda
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Publication number: 20120187611Abstract: A metal powder composition including: an iron or iron-based powder composition, and a lubricating combination including a substance A, a substance B, and a substance C; wherein: substance A is a polyolefin, substance B is chosen from a group of saturated and unsaturated fatty acid amides, saturated and unsaturated fatty acid bisamides, saturated fatty alcohols and fatty acid glycerols, and substance C is an amide oligomer having a molecular weight between 500 g/mol and 30 000 g/mol; and wherein the amounts of respective substances A, B and C in weight percent of the iron or iron-based powder composition are: 0.05?A+B<0.4 wt %, C?0.3 wt %, A+B+C?2.0 wt %, and the relation between substances A and B is: B/A>0.5. Also, a method of producing a metal powder composition and a method for producing a green component.Type: ApplicationFiled: September 1, 2010Publication date: July 26, 2012Applicant: HOGANAS AB (PUBL)Inventors: Mats Larsson, Karin Olsson, Hilmar Vidarsson
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Publication number: 20120187612Abstract: There are provided a permanent magnet and a manufacturing method thereof capable of densely sintering the entirety of the magnet without making a gap between a main phase and a grain boundary phase in the sintered magnet. To fine powder of milled neodymium magnet is added an organometallic compound solution containing an organometallic compound expressed with a structural formula of M-(OR)X (M represents Dy or Tb, R represents a substituent group consisting of a straight-chain or branched-chain hydrocarbon, X represents an arbitrary integer) so as to uniformly adhere the organometallic compound to particle surfaces of the neodymium magnet powder. Thereafter, desiccated magnet powder is held for several hours in hydrogen atmosphere at 200 through 900 degrees Celsius. Thereafter, the powdery calcined body calcined through the calcination process in hydrogen is held for several hours in vacuum atmosphere at 200 through 600 degrees Celsius for a dehydrogenation process.Type: ApplicationFiled: March 28, 2011Publication date: July 26, 2012Applicant: Nitto Denko CorporationInventors: Izumi Ozeki, Katsuya Kume, Keisuke Hirano, Tomohiro Omure, Keisuke Taihaku, Toshinobu Hoshino, Takashi Ozaki
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Publication number: 20110267160Abstract: The present invention relates to a permanent magnet manufactured by steps of: pulverizing a magnet raw material into fine particles having a grain size of 3 ?m or less; mixing the pulverized magnet raw material with a rust preventive oil in which a high-melting metal element-containing organic compound or a precursor of a high-melting ceramic is dissolved, thereby preparing a slurry; compression molding the slurry to form a molded body; and sintering the molded body.Type: ApplicationFiled: April 14, 2009Publication date: November 3, 2011Applicant: NITTO DENKO CORPORATIONInventors: Izumi Ozeki, Katsuya Kume, Junichi Nakayama, Yuuki Fukuda, Toshinobu Hoshino, Tomokazu Horio
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Publication number: 20110121498Abstract: The present invention relates to a method for producing a rare earth sintered magnet including the steps of: molding a mixture of magnetic powder containing a rare earth compound and oil-extended rubber containing oil and rubber to produce a molded body; removing the oil-extended rubber from the molded body; and calcining the molded body from which the oil-extended rubber is removed to produce a rare earth sintered magnet 10.Type: ApplicationFiled: November 22, 2010Publication date: May 26, 2011Applicant: TDK CorporationInventors: Shuichiro IRIE, Raitaro Masaoka, Toshiya Hozumi, Tetsuya Chiba
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Patent number: 7927501Abstract: A magnet comprising magnetic powder containing at least one rare earth metal element, and an oxide binder for binding the magnetic powder, wherein an inter-face distance of the binder determined by diffraction analysis is 0.25 to 2.94 nm. The disclosure also discloses a method of manufacturing a magnet comprising; compacting magnetic powder containing at least one rare earth element under pressure in a mold; impregnating the compacted magnetic powder molding with a precursor solution of an oxide material; and heat-treating the compacted magnetic molding impregnated with the precursor thereby to impart an inter-face distance determined by diffraction analysis to the binder in the compacted molding. The distance is 0.25 to 2.94 nm.Type: GrantFiled: November 20, 2007Date of Patent: April 19, 2011Assignee: Hitachi, Ltd.Inventors: Matahiro Komuro, Yuichi Satsu, Takao Imagawa, Hiroyuki Suzuki
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Publication number: 20110043311Abstract: The present invention relates to a permanent magnet manufactured by steps of: pulverizing a magnet raw material; mixing the pulverized magnet raw material with a rust preventive oil in which a Dy compound or a Tb compound is dissolved, thereby preparing a slurry; compression molding the slurry to form a molded body; and sintering the molded body.Type: ApplicationFiled: April 14, 2009Publication date: February 24, 2011Applicant: NITTO DENKO CORPORATIONInventors: Izumi Ozeki, Katsuya Kume, Junichi Nakayama, Yuuki Fukuda, Toshinobu Hoshino, Tomokazu Horio
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Publication number: 20110037548Abstract: The present invention relates to a permanent magnet manufactured by steps of: wet-pulverizing a high-melting metal element-containing organic compound or a precursor of a high-melting ceramic in a solvent together with a magnet raw material to pulverize the magnet raw material into fine particles having a grain size of 3 ?m or less and to coat a surface of the pulverized magnet raw material with the high-melting metal element-containing organic compound or the precursor of the high-melting ceramic; adding a resin binder to the magnet raw material coated with the high-melting metal element-containing organic compound or the precursor of the high-melting ceramic; producing a slurry by kneading the magnet raw material and the resin binder; molding the slurry into a sheet form to prepare a green sheet; and sintering the green sheet.Type: ApplicationFiled: April 14, 2009Publication date: February 17, 2011Applicant: NITTO DENKO CORPORATIONInventors: Izumi Ozeki, Katsuya Kume, Junichi Nakayama, Yuuki Fukuda, Toshinobu Hoshino, Tomokazu Horio
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Publication number: 20110018664Abstract: The present invention relates to a permanent magnet obtained by wet-mixing a Dy compound or a Tb compound with a magnet raw material to coat a surface of the magnet raw material with the Dy compound or the Tb compound, and sintering a green sheet obtained by mixing the resulting magnet raw material with a resin binder and molding the resulting mixture. Since the present invention has the above-mentioned constitution, it becomes possible to sufficiently improve coercive force by Dy or Tb while decreasing the amount of Dy or Tb used. Further, it can be prevented that Dy or Tb is solid-solutionized in magnet particles to decrease residual magnetization.Type: ApplicationFiled: March 17, 2009Publication date: January 27, 2011Applicant: NITTO DENKO CORPORATIONInventors: Izumi Ozeki, Katsuya Kume, Junichi Nakayama, Yuuki Fukuda, Toshinobu Hoshino, Tomokazu Horio
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Publication number: 20110012700Abstract: The present invention relates to a permanent magnet obtained by sintering a green sheet which is produced by mixing a magnet raw material with a resin binder and molding the resulting mixture, and a method for producing the same. Since the present invention has such a constitution, the contraction due to sintering becomes uniform, whereby the deformations such as warpage and depressions do not occur after sintering. Further, it is unnecessary to perform the conventional correcting processing after sintering, which can simplify the production steps, because the pressure unevenness at the time of pressing disappears. Therefore, it becomes possible to mold the permanent magnet with a high degree of dimension accuracy. Furthermore, even when the permanent magnet is reduced in film thickness, the magnetic characteristics are not deteriorated by the processing-deteriorated layer on the surface.Type: ApplicationFiled: March 17, 2009Publication date: January 20, 2011Applicants: NTTO DENKO CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Izumi Ozeki, Katsuya Kume, Junichi Nakayama, Yuuki Fukuda, Toshinobu Hoshino, Tomokazu Horio, Kenji Nakamura
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Publication number: 20100224822Abstract: The present invention relates to ferromagnetic powders with an electrically insulating layer on iron particles intended for the manufacture of components having improved soft magnetic properties at low and medium frequencies. The invention comprises an iron powder coated with a dielectric insulating layer comprising boron bearing compounds to form an insulated ferromagnetic powder. The present invention also relates to a method of making these insulated ferromagnetic powders. The present invention further relates to a method of synthesizing a product made from insulated ferromagnetic powders via a post-heat treatment at a moderate temperature (300° C. to 700° C.), to form a glass-like coating which acts as an electrical insulator. A preferred embodiment of the present invention is obtained when small amounts of alkali bearing compounds are added to the precursors to modify the coating chemistry and significantly increase the electrical resistivity after heat treatment.Type: ApplicationFiled: March 5, 2009Publication date: September 9, 2010Applicant: Quebec Metal Powders, Ltd.Inventors: Guillem Vachon, Claude Gelinas
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Patent number: 7712213Abstract: A method is provided for making an encapsulated stack of circuit boards. The method includes assembling the stack of circuit boards from a plurality of circuit boards, the circuit boards being spaced apart from each other; inserting the stack into an internal volume of a shell, the shell having a first end and a second end opposite the first end, an input orifice adjacent the first end, and an output orifice adjacent the second end and on a side opposite the input orifice; positioning the shell such that the input orifice is at a lowest point of any part of the internal volume of the shell, and such that the output orifice is at a highest point of any part of the internal volume of the shell; angling the shell relative to horizontal; and injecting an encapsulating compound into the input orifice to fill the internal volume of the shell with the encapsulating compound.Type: GrantFiled: December 1, 2006Date of Patent: May 11, 2010Assignee: AAI CorporationInventor: Michael J. Karmazyn
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Publication number: 20090302512Abstract: The invention relates to a soft-magnetic material comprising a micro fraction composed of particles of a soft-magnetic material having a particle size in the range from 1 to 100 ?m and a nano fraction composed of particles of a soft-magnetic material having a particle size in the range from 100 to 200 nm, where the proportion of the nano fraction based on the total mass of micro fraction and nano fraction is from 5 to 70% by mass and the particles of the micro fraction and the particles of the nano fraction optionally consist of the same material, and also a process for producing an article composed of the soft-magnetic material.Type: ApplicationFiled: June 5, 2009Publication date: December 10, 2009Applicant: Tridelta Weichferrite GmbHInventors: Silvio Gablenz, Marko Kloucek
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Publication number: 20080248245Abstract: A soft magnetic material includes a plurality of composite magnetic particles. Each of the plurality of composite magnetic particles has a metal magnetic particle including iron, a lower film surrounding the surface of the metal magnetic particle and including a nonferrous metal, and an insulating upper film surrounding the surface of the lower film and including an inorganic compound. The inorganic compound contains at least one element of oxygen and carbon. The nonferrous metal has an affinity with at least one of oxygen and carbon that is larger than such affinity of iron. The nonferrous metal has a diffusion coefficient with respect to at least one of oxygen and carbon that is smaller than such diffusion coefficient of iron. Thus, a soft magnetic material that provides desirable magnetic properties, a method of manufacturing a soft magnetic material, a dust core, and a method of manufacturing a dust core are provided.Type: ApplicationFiled: July 20, 2006Publication date: October 9, 2008Inventors: Toru Maeda, Haruhisa Toyoda, Naoto Igarashi, Kazuhiro Hirose, Seiji Ishitani, Hiroko Morii, Kazuyuki Hayashi
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Patent number: 7425284Abstract: The purpose of the invention is a process for making a solid part designed to form all or part of an anode for the production of aluminium by fused bath electrolysis, containing a cermet formed from at least one metallic oxide such as a mixed oxide with spinel structure, and at least one metallic phase, in which a mixed oxide is used containing a metal R in the form of a cation in its chemical structure, the said metal R being fully or partly reducible by a reduction operation during the manufacturing process, so as to form all or part of the said metallic phase. This process can provide a cermet with a uniform distribution of fine metallic particles.Type: GrantFiled: October 5, 2004Date of Patent: September 16, 2008Assignee: Aluminum PechineyInventors: Philippe Tailhades, Abel Rousset, Armand Gabriel, Véronique Laurent, Valérie Baco-Carles, Airy-Pierre Lamaze
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Cobalt ferrite based magnetostrictive materials for magnetic stress sensor and actuator applications
Patent number: 7326360Abstract: Magnetostrictive material based on cobalt ferrite is described. The cobalt ferrite is substituted with transition metals (such manganese (Mn), chromium (Cr), zinc (Zn) and copper (Cu) or mixtures thereof) by substituting the transition metals for iron or cobalt to form substituted cobalt ferrite that provides mechanical properties that make the substituted cobalt ferrite material effective for use as sensors and actuators. The substitution of transition metals lowers the Curie temperature of the material (as compared to cobalt ferrite) while maintaining a suitable magnetostriction for stress sensing applications.Type: GrantFiled: July 23, 2004Date of Patent: February 5, 2008Assignee: Iowa State University Research Foundation, Inc.Inventors: David C. Jiles, Jason A. Paulsen, John E. Snyder, Chester C. H. Lo, Andrew P. Ring, Keith A. Bormann -
Patent number: 7255807Abstract: A ferrite magnetic powder for bond magnet that experiences only small decrease in coercivity when molded into a bond magnet is provided, which is a ferrite magnetic powder that includes an alkaline-earth metal constituent and exhibits a decrease in coercivity of not greater than 600 Oe when subjected to a prescribed molding test. The magnetic powder can be obtained by mixing a fine ferrite powder of an average particle diameter of greater than 0.50 to 1.0 ?m and a coarse ferrite powder of an average particle diameter of greater than 2.50 to 5.0 ?m at ratio to incorporate the fine powder at a content ratio of 15-40 wt %.Type: GrantFiled: April 22, 2004Date of Patent: August 14, 2007Assignee: Dowa Mining Co., Ltd.Inventors: Masayasu Senda, Shinichi Suenaga, Keisuke Ayabe, Toshiyuki Sakai
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Ferrite core for RFID application, method of manufacturing the same, and ferrite coil using the same
Patent number: 7195717Abstract: A ferrite core comprising a sintered oxide containing at least 48.6 to 53.9 mol % of Fe on Fe2O3 basis, 12.3 to 35.2 mol % of Ni on NiO basis and 16.4 to 37.0 mol % of Zn on ZnO basis as metal elements, and contains a crystal phase comprising two or more kinds of solid solutions selected from NiFe2O4, ZnFe2O4 and FeFe2O4, wherein full width at half maximum of a diffraction peak, of crystal phase of which diffraction angle 2? is in a range from 34.6 to 36.4° as measured by X-ray diffraction analysis using Cu—K? beam, is 0.4° or less.Type: GrantFiled: July 27, 2004Date of Patent: March 27, 2007Assignee: Kyocera CorporationInventors: Chisato Ishida, Masayuki Moriyama, Hidehiro Takenoshita -
Patent number: 6571858Abstract: A method of manufacturing a preform for compounding use which, is to be impregnated with a molten metal to be compounded with a matrix material, is provided. The method includes the step of mixing short fibers, ceramic particles and a binder material together to make a mixture. The average of lengths of the short fibers is 100 to 200 &mgr;m while the volumetric percentage of the short fibers is 1 to 7%. The content of the binder material in the mixture is 0.3 to 5.0 mass %. The method includes also the steps of forming the mixture so as to have a predetermined shape, and sintering the mixture at a temperature of 1000 to 1150° C. to form the preform. Thus, it is restrained that the preform is deformed or an un-reinforced region is formed in the compounded portion.Type: GrantFiled: September 20, 2001Date of Patent: June 3, 2003Assignee: Mazda Motor CorporationInventor: Makoto Fujita
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Patent number: 6562458Abstract: The invention concerns a process for the preparation of an insulated soft magnetic powder comprising the steps of mixing particles of a soft magnetic iron base powder with an acidic, aqueous insulating-layer forming solution, in which MgO has been dissolved; and drying the obtained mixture to obtain an electrically insulating Mg containing layer on the particle surfaces. The invention also concerns the powder per se as well as compressed soft magnetic powder cores prepared from the powder.Type: GrantFiled: January 16, 2001Date of Patent: May 13, 2003Assignee: Höganäs ABInventors: Cecilia Elgelid, Anne Larsson-Westberg, Lars-Åke Larsson
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Publication number: 20030062660Abstract: A method for forming composite parts of two or more dissimilar materials by injection molding. Two or more different metallic- or ceramic-based powder materials are used to form two or more different feedstocks, which are each melted and injected under heat and pressure into mold cavities and allowed to solidify to form a composite green compact. In an example of the present invention, two or more powder materials are each mixed with a binder system and granulated to form feedstocks, the feedstocks are melted and concurrently or sequentially injected into a mold and allowed to solidify, and the solidified composite green compact is then subjected to binder removal and sintering processes.Type: ApplicationFiled: October 3, 2001Publication date: April 3, 2003Inventors: Bradley D. Beard, Matthew W. Crump, Tom L. Stuart
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Patent number: 6517744Abstract: A heat-conductive sheet comprising a cured or semi-cured binder wherein a carbon fiber is orientated in the direction of the thickness of the heat-conductive sheet. This heat-conductive sheet exhibits a high anisotropic heat conductivity along the direction of the thickness thereof to thereby enable efficiently releasing heat from a heating element such as a semiconductor element or semiconductor package. Moreover, the heat-conductive sheet is excellent in not only heat resistance, durability and mechanical strength but also adherence to the heating element.Type: GrantFiled: November 14, 2000Date of Patent: February 11, 2003Assignee: JSR CorporationInventors: Takeo Hara, Shin-ichiro Iwanaga, Hozumi Sato, Ryoji Setaka
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Patent number: 6488885Abstract: A health support device having a lamination of a semiconductor film on a surface of a partially-reduced sintered material of titanium oxide. The semiconductor film is preferably a p-type semiconductor film of silicon or germanium. The partially-reduced sintered material is preferably represented by TiO2−x, where 0<×<0.5. The thickness of the semiconductor film is preferably from 1 nm to 500 nm. In production, a mixture of a titanium oxide powder and a binder is press-molded, and the molded material is sintered at a temperature of from 500° C. to 1100° C. in a vacuum, inert or reducing atmosphere. A p-type semiconductor film is formed on a surface of the resulting partially-reduced sintered material of titanium oxide.Type: GrantFiled: September 19, 2000Date of Patent: December 3, 2002Assignee: Furukawa Co., Ltd.Inventors: Saburo Ishiguro, Yoshitsugu Fujita, Tetsuhiro Iwata
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Patent number: 6423264Abstract: A method of a manufacturing rotating electromagnetic component to have both soft and hard (permanent) magnet regions, in which powder technologies are used to net-shape mold the component. A soft magnet powder material and an insert or powder of a permanent magnet material are compacted to form a rotating electromagnetic body containing soft and hard magnet regions. A partial sintering operation is then performed on the body at a temperature of 1600° F. (about 870° C.) or less, preferably about 1400° F. to 1500° F. (about 760° C. and 830° C.), and most preferably at 1500° F. to at least partially fuse the soft magnet powder materials with the permanent magnet material. The soft powder component of the resulting electromagnetic body is sufficiently fused to exhibit mechanical properties comparable to a fully sintered body (i.e., sintered at 2050° F. (about 1120° C.) or more), but without degrading the magnetic properties of the hard magnet region.Type: GrantFiled: October 14, 1999Date of Patent: July 23, 2002Assignee: Delphi Technologies, Inc.Inventor: David Earl Gay
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Publication number: 20020084439Abstract: An extrudable magnet composition includes composite particles including thermoplastic resin and magnetic material, and a surface additive selected from silicon dioxide particles and ferrite particles, wherein the surface additive is applied to a surface of the composite particles.Type: ApplicationFiled: December 28, 2000Publication date: July 4, 2002Applicant: Xerox CorporationInventors: Steven C. Hart, Lois A. Eckstrom
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Patent number: 6403017Abstract: A process for producing Mn—Zn ferrite having large electrical resistance and being durable to the use in high frequency region exceeding 1 MHz easily and at low cost is disclosed. The process comprises pressing a mixed powder comprising a composition of 44.0 to 50.0 mol % of Fe2O3, 4.0 to 26.5 mol % of ZnO, 0.1 to 8.0 mol % of at least one member selected from the group consisting of TiO2 and SnO2, and the remainder being MnO, and if desired 0.1 to 16.0 mol % of CuO, sintering the resulting green compact in the air or an atmosphere containing an appropriate amount of oxygen, and then cooling the green compact, thereby securing the estimated high initial permeability even in a high frequency region of 1 MHz or more.Type: GrantFiled: November 18, 1999Date of Patent: June 11, 2002Assignee: Minebea Co., Ltd.Inventors: Osamu Kobayashi, Osamu Yamada, Koji Honda, Shunji Kawasaki
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Patent number: 6387293Abstract: A composition for a rare earth bonded magnet, the rare earth bonded magnet and the method for manufacturing the rare earth bonded magnet are provided that produce little decline in mechanical strength caused by the addition of a lubricant and have excellent molding properties. The rare earth bonded magnet of the present invention is manufactured from the composition for the magnet that contains rare earth magnetic powder, binding resin containing thermoplastic resin, and fluorine-based resin powder, by compaction molding, extrusion molding or injection molding. The fluorine-based resin powder has the properties of improving mainly lubrication between a molding and a metallic mold. The content of the fluorine-based resin powder in the composition for the rare earth bonded magnet is preferably less than 20 vol % relative to the thermoplastic resin, and the particle diameter of the fluorine-based resin powder is preferably 2-30 &mgr;m.Type: GrantFiled: March 16, 2000Date of Patent: May 14, 2002Assignee: Seiko Epson CorporationInventors: Koji Akioka, Yoshiki Nakamura, Ken Ikuma
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Patent number: 6379579Abstract: 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: GrantFiled: March 7, 2000Date of Patent: April 30, 2002Assignee: TDK CorporationInventor: Hiroshi Harada
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Publication number: 20020008336Abstract: Provided are an inexpensive Mn—Zn ferrite material having a high resistance, a high permeability, and a low core loss, a manufacturing method thereof, and a deflection yoke core using the material. The ferrite material contains, as main components, 43.0-49.5 mol % of Fe2O3, 33.5-49.0 mol % of MnO, and 8.0-17.0 mol % of ZnO, wherein the ratio of ZnO mol %/Fe2O3 mol % is in a range of 0.35 or less. Preferably, the ferrite material further contains, as sub-components, at least one or more of 0.006-0.12 wt % of CaO, 0.001-0.05 wt % of SiO2, and 0.1-1.0 wt % of Bi2O3. The oxygen concentration of its atmosphere for sintering of the deflection yoke core is specified in a range of 3 to 13%. Preferably, the cooling rate until cooled to 500° C. after the sintering is set in a range of 120° C./hr to 400° C./hr.Type: ApplicationFiled: July 20, 1999Publication date: January 24, 2002Inventors: SHUICHI OTOBE, TETUJI AKIYAMA, YASUYUKI MASUDA
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Patent number: 6296791Abstract: A process for producing Mn—Zn ferrite is disclosed, which enables regeneration and reuse of scraps of a sintered product. The process comprises reusing a powder obtained by milling the sintered product of Mn—Zn ferrite, subjecting the powder to a component adjustment so as to have a composition of 44.0 to 50.0 mol % of Fe2O3, 4.0 to 26.5 mol % of ZnO, 0.1 to 8.0 mol % of at least one member selected from the group consisting of TiO2 and SnO2, and the remainder being MnO, and optionally 0.1 to 16.0 mol % of CuO, pressing the resulting mixed powder after the component adjustment, and then sintered a green compact.Type: GrantFiled: April 3, 2000Date of Patent: October 2, 2001Assignee: Minebea Co., Ltd.Inventors: Osamu Kobayashi, Osamu Yamada, Koji Honda, Shunji Kawasaki
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Publication number: 20010019771Abstract: The invention concerns a process for the preparation of an insulated soft magnetic powder comprising the steps of mixing particles of a soft magnetic iron base powder with an acidic, aqueous insulating-layer forming solution, in which MgO has been dissolved; and drying the obtained mixture to obtain an electrically insulating Mg containing layer on the particle surfaces. The invention also concerns the powder per se as well as compressed soft magnetic powder cores prepared from the powder.Type: ApplicationFiled: January 16, 2001Publication date: September 6, 2001Inventors: Cecilia Elgelid, Anne Larsson-Westberg, Lars-Ake Larsson
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Patent number: 6248289Abstract: A method for molding relatively complex and large shapes by a co-injection molding process which results in a significantly less expensive and lighter molded product. The process steps include first injection molding a thermoplastic material highly densified with ceramic or stainless steel particulate material to form a shell structure having a homogeneous dispersion of the ceramic or stainless steel material within its matrix and then injecting a significantly less expensive material into the core of the preformed thermoplastic/ceramic or stainless steel structure and thereafter sintering the resulting molded structure. The resultant structure is a hollow shell of highly densified ceramic or stainless steel.Type: GrantFiled: June 23, 2000Date of Patent: June 19, 2001Assignee: Xerox CorporationInventor: Jay lee Schneider
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Patent number: 6221270Abstract: A process for producing a compound for a rare earth metal resin-bonded magnet includes: a slurry preparation step of mixing materials containing a magnetic alloy powder of a rare earth metal alloy, a resin binder, and an organic solvent into a slurry; and a drying step of spraying and drying the slurry by means of a spray dryer apparatus to produce the compound containing the magnetic alloy powder of the rare earth metal alloy and the resin binder.Type: GrantFiled: June 18, 1999Date of Patent: April 24, 2001Assignee: Sumitomo Special Metal Co., Ltd.Inventors: Katsuyoshi Saito, Yasunari Kaneko, Naoyuki Ishigaki, Shin Mishima, Shinji Otsuki, Yoshihiko Nishino
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Patent number: 6217820Abstract: A method of manufacturing a ferrite sintered body includes the steps of: adding B4C in a ferrite raw material and firing the ferrite raw material, whereby the ferrite sintered body has a high &mgr;i and a high Q, is less irregular in its characteristics, has a high volume resistivity and is capable of preventing deterioration of insulating resistance.Type: GrantFiled: December 2, 1999Date of Patent: April 17, 2001Assignee: Murata Manufacturing Co., Ltd.Inventors: Junji Kurobe, Hideo Ajichi, Takashi Kodama, Takehiro Konoike, Akihiro Nakamura
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Patent number: 6193903Abstract: Ceramic-coated powdered ferromagnetic materials for forming magnetic articles, and which maintain the mechanical and magnetic properties of the articles at high temperatures, such as during annealing to relieve stresses induced during the forming operation. The ceramic coatings are formed by one of several techniques to provide an encapsulating layer on each ferromagnetic particle. The particles are then compacted to form a solid magnetic article, which can be annealed without concern for degrading the ceramic coating.Type: GrantFiled: May 14, 1999Date of Patent: February 27, 2001Assignee: Delphi Technologies, Inc.Inventors: David Earl Gay, David Allen Score
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Patent number: 6174453Abstract: Disclosed is a method for the preparation of a ferrite beads composition suitable for compression-molding into a compression-molded ferrite body to be subjected to a sintering heat treatment to give a sintered ferrite member having usefulness as an electromagnetic material. The method comprises the steps of: forming ferrite beads from ferrite particles and an organic binder compound; and uniformly mixing the ferrite beads with a limited amount of a higher fatty acid ester of a hexitan compound such as sorbitan mono- or sesquioleate. The ferrite beads composition of the invention is advantageous not only in respect of the behavior in compression molding such as high density of the compression-molded body, low withdrawal pressure from the metal mold and a decrease in the phenomenon of springback but also in respect of the properties of the ferrite body after sintering.Type: GrantFiled: September 21, 1999Date of Patent: January 16, 2001Assignee: TDK CorporationInventor: Hiroshi Harada
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Patent number: 6113843Abstract: The process for the preparation of an oxide magnetic compact of the invention comprises:a step of preparing a mixed material which comprises 44 to 50 mole % of iron calculated as Fe.sub.2 O.sub.3, 0.1 to 8 mole % of manganese calculated as Mn.sub.2 O.sub.3, with the sum of iron and manganese being 50 to 54 mole % calculated as Fe.sub.2 O.sub.3 and Mn.sub.2 O.sub.3, 20 to 38 mole % of magnesium calculated as MgO, 17 to 22 mole % of zinc calculated as ZnO and not more than 5 mole % of copper calculated as CuO, anda step of molding the aforesaid mixed material to a predetermined shape and then firing it in an atmosphere of low oxygen concentration of 2.5 to 12% by volume. Therefore, there appears an extremely excellent effect that the oxide magnetic compact having excellent electromagnetic properties can be obtained at low cost.Type: GrantFiled: March 23, 1999Date of Patent: September 5, 2000Assignee: TDK CorporationInventors: Takuya Aoki, Taku Murase, Kazuhiro Takakura, Jun Sawai, Naoyoshi Sato
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Patent number: 6086781Abstract: The magnetic powder and the sintered magnet of the invention contains a primary phase of a hexagonal ferrite containing A, Co or R wherein A represents Sr, Ba or Ca, and R represents at least one element which may be rare earth elements including Y, and Bi, and have at least two different Curie temperatures, wherein the two different Curie temperatures are present within a range of from 400 to 480.degree. C., and an absolute value of a difference therebetween is 5.degree. C. or more. As both the saturation magnetization and the magnetic anisotropy of the M type ferrite therein are increased, the magnetic powder and the wintered magnet have a high residual magnetic flux density and a high coercive force, which conventional M type ferrite magnets could not have, while having excellent temperature characteristics of coercive force.Type: GrantFiled: May 19, 1999Date of Patent: July 11, 2000Assignee: TDK CorporationInventors: Hitoshi Taguchi, Kiyoyuki Masuzawa, Yoshihiko Minachi, Kazumasa Iida, Mitsuaki Sasaki, Fumihiko Hirata
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Patent number: 6063322Abstract: A method for producing shaped bodies from hard ferrites, includes (a) providing a powder of hard ferrite material having a fine particle size; (b) adding to the powder a plastifying and bonding agent which comprises (a) at least one of cyclododecane, cyclododecanol, and stearyl alcohol and (b) stearic acid to provide a mixture; (c) shaping the mixture into a blank; (d) heating at a temperature effective to remove the plastifying and bonding agent from the blank; and (e) subsequently heating the blank to a temperature effective to sinter the powder. The method is suitable for the production of magnets, in particular segmental magnets.Type: GrantFiled: January 10, 1997Date of Patent: May 16, 2000Assignee: Robert Bosch GmbHInventors: Waldemar Draxler, Wilfried Aichele, Uwe Laukant, Horst Boeder
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Patent number: 5711912Abstract: A process for forming a ceramic coated element formed by first encapsulating the element within a sacrificial material and then encapsulating the element and the sacrificial material with an unsintered ceramic material. The resultant combination of materials and elements is then controllably heated to a temperature that burns the sacrificial material prior to the curing of the ceramic material so as to permit the permeation of the burned sacrificial material through the ceramic material. As the ceramic material is sintered it shrinks around the encapsulated element to form the ceramic coated element. In the preferred embodiment of the invention the coated element is a magnet or magnetizable material that is magnetized to a preferred axis of magnetization during the cooling phase of the process.Type: GrantFiled: June 16, 1996Date of Patent: January 27, 1998Assignee: Eastman Kodak CompanyInventors: Dilip K. Chatterjee, Edward Paul Furlani, Syamal K. Ghosh