Patents by Inventor Kozo Ogi
Kozo Ogi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11041229Abstract: An object of the present invention is to provide metal powder that can be used to form an external electrode, which is excellent in solder wettability and solder leach resistance while having a layer structure with fewer layers than in the related art and, furthermore, is excellent in electrical conductivity. This silver-coated alloy powder comprises a coating layer on a surface of an alloy core particle containing copper, nickel, zinc, and inevitable impurities, the coating layer containing silver.Type: GrantFiled: August 31, 2017Date of Patent: June 22, 2021Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.Inventors: Kyoso Masuda, Kenichi Inoue, Yuki Kaneshiro, Atsushi Ebara, Yoshiyuki Michiaki, Kozo Ogi, Takahiro Yamada, Masahiro Yoshida
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Patent number: 10458004Abstract: To provide a silver-bismuth powder, which includes: silver; and bismuth, wherein a mass ratio (silver:bismuth) of the silver to the bismuth is 95:5 to 40:60, wherein a cumulative 50% point of particle diameter (D50) of the silver-bismuth powder in a volume-based particle size distribution thereof as measured by a laser diffraction particle size distribution analysis is 0.1 ?m to 10 ?m, and wherein an oxygen content of the silver-bismuth powder is 5.5% by mass or less.Type: GrantFiled: October 21, 2015Date of Patent: October 29, 2019Assignee: DOWA Electronics Materials Co., Ltd.Inventors: Kozo Ogi, Kenichi Inoue, Atsushi Ebara, Akihiro Asano, Hideyuki Fujimoto, Takahiro Yamada
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Publication number: 20190194778Abstract: An object of the present invention is to provide metal powder that can be used to form an external electrode, which is excellent in solder wettability and solder leach resistance while having a layer structure with fewer layers than in the related art and, furthermore, is excellent in electrical conductivity. This silver-coated alloy powder comprises a coating layer on a surface of an alloy core particle containing copper, nickel, zinc, and inevitable impurities, the coating layer containing silver.Type: ApplicationFiled: August 31, 2017Publication date: June 27, 2019Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.Inventors: Kyoso MASUDA, Kenichi INOUE, Yuki KANESHIRO, Atsushi EBARA, Yoshiyuki MICHIAKI, Kozo OGI, Takahiro YAMADA, Masahiro YOSHIDA
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Patent number: 10062473Abstract: A silver-coated copper alloy powder, which has a low volume resistivity and excellent storage stability (reliability), is produced by coating a copper alloy powder, which has a chemical composition comprising 1 to 50 wt % of at least one of nickel and zinc and the balance being copper and unavoidable impurities (preferably a copper alloy powder wherein a particle diameter (D50 diameter) corresponding to 50% of accumulation in cumulative distribution of the copper alloy powder, which is measured by a laser diffraction particle size analyzer, is 0.1 to 15 ?m), with 7 to 50 wt % of a silver containing layer, preferably a layer of silver or an silver compound.Type: GrantFiled: January 15, 2013Date of Patent: August 28, 2018Assignee: Dowa Electronics Materials Co., Ltd.Inventors: Kenichi Inoue, Kozo Ogi, Atsushi Ebara, Yuto Hiyama, Takahiro Yamada, Toshihiko Ueyama
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Publication number: 20160040271Abstract: To provide a silver-bismuth powder, which includes: silver; and bismuth, wherein a mass ratio (silver:bismuth) of the silver to the bismuth is 95:5 to 40:60, wherein a cumulative 50% point of particle diameter (D50) of the silver-bismuth powder in a volume-based particle size distribution thereof as measured by a laser diffraction particle size distribution analysis is 0.1 ?m to 10 ?m, and wherein an oxygen content of the silver-bismuth powder is 5.5% by mass or less.Type: ApplicationFiled: October 21, 2015Publication date: February 11, 2016Inventors: Kozo OGI, Kenichi INOUE, Atsushi EBARA, Akihiro ASANO, Hideyuki FUJIMOTO, Takahiro YAMADA
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Patent number: 8992701Abstract: After a reducing agent is added to a water reaction system containing silver ions to deposit silver particles by reduction, the silver particles are dried to obtain a silver powder which is heat-treated at a temperature of higher than 100° C. and lower than 400° C. The silver powder thus heat-treated has a maximum coefficient of thermal expansion of not greater than 1.5% at a temperature of 50° C. to 800° C., and has no heating peak when the silver powder is heated from 50° C. to 800° C. The silver powder has an ignition loss of not greater than 1.0% when the silver powder is ignited until the weight of the silver powder is constant at 800° C. The silver powder has a tap density of not less than 2 g/cm3 and a BET specific surface area of not greater than 5 m2/g.Type: GrantFiled: May 10, 2012Date of Patent: March 31, 2015Assignee: Dowa Mining Co., Ltd.Inventors: Takatoshi Fujino, Kozo Ogi
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Publication number: 20140346413Abstract: A silver-coated copper alloy powder, which has a low volume resistivity and excellent storage stability (reliability), is produced by coating a copper alloy powder, which has a chemical composition comprising 1 to 50 wt % of at least one of nickel and zinc and the balance being copper and unavoidable impurities (preferably a copper alloy powder wherein a particle diameter (D50 diameter) corresponding to 50% of accumulation in cumulative distribution of the copper alloy powder, which is measured by a laser diffraction particle size analyzer, is 0.1 to 15 ?m), with 7 to 50 wt % of a silver containing layer, preferably a layer of silver or an silver compound.Type: ApplicationFiled: January 15, 2013Publication date: November 27, 2014Inventors: Kenichi Inoue, Kozo Ogi, Atsushi Ebara, Yuto Hiyama, Takahiro Yamada, Toshihiko Ueyama
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Patent number: 8282702Abstract: After a reducing agent is added to a water reaction system containing silver ions to deposit silver particles by reduction, the silver particles are dried to obtain a silver powder which is heat-treated at a temperature of higher than 100° C. and lower than 400° C. The silver powder thus heat-treated has a maximum coefficient of thermal expansion of not greater than 1.5% at a temperature of 50° C. to 800° C., and has no heating peak when the silver powder is heated from 50° C. to 800° C. The silver powder has an ignition loss of not greater than 1.0% when the silver powder is ignited until the weight of the silver powder is constant at 800° C. The silver powder has a tap density of not less than 2 g/cm3 and a BET specific surface area of not greater than 5 m2/g.Type: GrantFiled: November 21, 2005Date of Patent: October 9, 2012Assignee: Dowa Mining Co., Ltd.Inventors: Takatoshi Fujino, Kozo Ogi
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Publication number: 20120219453Abstract: After a reducing agent is added to a water reaction system containing silver ions to deposit silver particles by reduction, the silver particles are dried to obtain a silver powder which is heat-treated at a temperature of higher than 100° C., and lower than 400° C. The silver powder thus heat-treated has a maximum coefficient of thermal expansion of not greater than 1.5% at a temperature of 50° C. to 800° C., and has no heating peak when the silver powder is heated from 50° C. to 800° C. The silver powder has an ignition loss of not greater than 1.0% when the silver powder is ignited until the weight of the silver powder is constant at 800° C. The silver powder has a tap density of not less than 2 g/cm3 and a BET specific surface area of not greater than 5 m2/g.Type: ApplicationFiled: May 10, 2012Publication date: August 30, 2012Applicant: DOWA MINING CO., LTD.Inventors: Takatoshi Fujino, Kozo Ogi
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Publication number: 20120045573Abstract: Provided is a silver conductive film, a thin film of silver comprising a sintered layer of silver particles having a mean particle size DTEM of at most 100 nm. Its specific resistance is at most 5 ??·cm, the ratio of the voids in the sintered layer is at most 3/?m2, and the film has a texture structure with a surface roughness Ra of from 10 to 100 nm. The silver conductive film having such a texture structure may be produced according to a production process comprising a step of applying a silver particle dispersion of silver particles having a mean particle size DTEM of at most 100 nm dispersed in a non-polar or poorly-polar liquid organic medium having a boiling point of from 60 to 300° C., onto a substrate to form a coating film thereon, and thereafter baking the coating film.Type: ApplicationFiled: October 14, 2011Publication date: February 23, 2012Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.Inventors: Kimitaka SATO, Yutaka HISAEDA, Taku OKANO, Kozo Ogi
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Patent number: 8003019Abstract: A silver particle dispersion liquid comprising a silver particle powder having an average particle diameter (DTEM) of 50 nm or less, the surface of the particle being covered with an organic protective material, dispersed in a non-polar or small polar liquid organic medium having a boiling point of 60 to 300° C., wherein the organic protective material is an amine compound having one or more unsaturated bonds in one molecule. The silver particle dispersion liquid can be produced by reducing a silver compound in a liquid including one or more alcohol or polyol acting as a reducing agent, wherein the reduction reaction is conducted in the presence of an amine compound having a molecular weight of 100 to 1,000 and having one or more unsaturated bonds in one molecule.Type: GrantFiled: January 9, 2007Date of Patent: August 23, 2011Assignee: Dowa Electronics Materials Co., Ltd.Inventors: Kimitaka Sato, Kozo Ogi
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Publication number: 20100038603Abstract: A silver particle dispersion liquid comprising a silver particle powder having an average particle diameter (DTEM) of 50 nm or less, the surface of the particle being covered with an organic protective material, dispersed in a non-polar or small polar liquid organic medium having a boiling point of 60 to 300° C., wherein the organic protective material is an amine compound having one or more unsaturated bonds in one molecule. The silver particle dispersion liquid can be produced by reducing a silver compound in a liquid including one or more alcohol or polyol acting as a reducing agent, wherein the reduction reaction is conducted in the presence of an amine compound having a molecular weight of 100 to 1,000 and having one or more unsaturated bonds in one molecule.Type: ApplicationFiled: January 9, 2007Publication date: February 18, 2010Inventors: Kimitaka Sato, Kozo Ogi
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Publication number: 20100025639Abstract: A silver particle composite powder produced by mixing a silver particle powder (A) which bears on the surface of each silver particle, an organic protective layer comprising an amine compound having at least one unsaturated bond in one molecule and having a molecular weight of from 100 to 1000, and has a mean particle diameter DTEM, as determined by TEM, of at most 50 nm and a silver particle powder (B) which bears on the surface of each silver particle, an organic protective layer comprising a fatty acid having a molecular weight of from 100 to 1000 and an amine compound having a molecular weight of from 100 to 1000 with at least any one of the fatty acid and the amine compound having at least one unsaturated bond in one molecule, and has a mean particle diameter DTEM of at most 50 nm, in a blend ratio by mass, A/B of from 3/1 to 1/3 in terms of silver.Type: ApplicationFiled: September 11, 2007Publication date: February 4, 2010Inventors: Kozo Ogi, Yutaka Hisaeda
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Patent number: 7641817Abstract: There is provided a method for producing a silver powder having excellent dispersibility and capable of forming a paste which do not form suspended matters by phase separation and which is printed on a substrate to form a film having a uniform thickness. In this method, an alkali or a complexing agent is added to an aqueous silver salt containing solution to form a silver oxide containing slurry or an aqueous silver complex salt containing solution. After or before silver particles are deposited by reduction by adding a reducing agent to the silver oxide containing slurry or aqueous silver complex salt containing solution while stirring it, at least one chelating agent selected from the group consisting of compounds having an azole structure, dicarboxylic acids, hydroxy carboxylic acids and salts thereof is added to a silver power containing slurry solution as a dispersing agent.Type: GrantFiled: January 28, 2005Date of Patent: January 5, 2010Assignee: Dowa Mining Co., Ltd.Inventors: Hiroshi Matsushima, Kozo Ogi
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Publication number: 20090236567Abstract: A powder of silver particles having an organic protective film, which has a broad particle size distribution of such that the CV value, as computed according to the following formula (1) in which the particle diameter is determined by TEM (transmission electromicroscopy), is at least 40%. The organic protective film comprises, for example, a fatty acid (oleic acid, etc.) having a molecular weight of from 100 to 1000 and an amine compound having a molecular weight of from 100 to 1000, and at least any one of the fatty acid and the amine compound has at least one unsaturated bond in one molecule.Type: ApplicationFiled: September 11, 2007Publication date: September 24, 2009Inventors: Kozo Ogi, Taku Okano
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Publication number: 20090053469Abstract: Provided is a silver conductive film, a thin film of silver comprising a sintered layer of silver particles having a mean particle size DTEM of at most 100 nm. Its specific resistance is at most 5 ??·cm, the ratio of the voids in the sintered layer is at most 3/?m2, and the film has a texture structure with a surface roughness Ra of from 10 to 100 nm. The silver conductive film having such a texture structure may be produced according to a production process comprising a step of applying a silver particle dispersion of silver particles having a mean particle size DTEM of at most 100 nm dispersed in a non-polar or poorly-polar liquid organic medium having a boiling point of from 60 to 300° C., onto a substrate to form a coating film thereon, and thereafter baking the coating film.Type: ApplicationFiled: January 9, 2007Publication date: February 26, 2009Inventors: Kimitaka Sato, Yutaka Hisaeda, Taku Okano, Kozo Ogi
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Patent number: 7462301Abstract: There is provided a method for producing a silver powder having excellent dispersibility and capable of forming a paste which do not form suspended matters by phase separation and which is printed on a substrate to form a film having a uniform thickness. In this method, an alkali or a complexing agent is added to an aqueous silver salt containing solution to form a silver oxide containing slurry or an aqueous silver complex salt containing solution. After or before silver particles are deposited by reduction by adding a reducing agent to the silver oxide containing slurry or aqueous silver complex salt containing solution while stirring it, at least one chelating agent selected from the group consisting of compounds having an azole structure, dicarboxylic acids, hydroxy carboxylic acids and salts thereof is added to a silver power containing slurry solution as a dispersing agent.Type: GrantFiled: April 17, 2007Date of Patent: December 9, 2008Assignee: Dowa Mining Co., Ltd.Inventors: Hiroshi Matsushima, Kozo Ogi
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Publication number: 20080035895Abstract: There is provided a method for a silver powder capable of decreasing the viscosity of a photosensitive paste using the silver powder and improving the film state, sensitivity and linearity of the paste even if the particle diameter of the silver powder is small. The surface of a silver powder produced by a wet reducing method is smoothed by a surface smoothing process for mechanically causing particles of the silver powder to collide with each other, and thereafter, silver agglomerates are removed by classification. The surface smoothing process is carried out by putting a dried silver powder into an apparatus, which is capable of mechanically fluidizing particles, e.g., a mixer or mill such as a cylindrical high-speed mixer, for mechanically causing the particles to collide with each other.Type: ApplicationFiled: October 3, 2007Publication date: February 14, 2008Inventors: Kozo Ogi, Yoshio Hasegawa
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Publication number: 20070181858Abstract: There is provided a method for producing a silver powder having excellent dispersibility and capable of forming a paste which do not form suspended matters by phase separation and which is printed on a substrate to form a film having a uniform thickness. In this method, an alkali or a complexing agent is added to an aqueous silver salt containing solution to form a silver oxide containing slurry or an aqueous silver complex salt containing solution. After or before silver particles are deposited by reduction by adding a reducing agent to the silver oxide containing slurry or aqueous silver complex salt containing solution while stirring it, at least one chelating agent selected from the group consisting of compounds having an azole structure, dicarboxylic acids, hydroxy carboxylic acids and salts thereof is added to a silver power containing slurry solution as a dispersing agent.Type: ApplicationFiled: April 17, 2007Publication date: August 9, 2007Applicant: DOWA MINING CO., LTD.Inventors: Hiroshi Matsushima, Kozo Ogi
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Publication number: 20060107791Abstract: After a reducing agent is added to a water reaction system containing silver ions to deposit silver particles by reduction, the silver particles are dried to obtain a silver powder which is heat-treated at a temperature of higher than 100° C. and lower than 400° C. The silver powder thus heat-treated has a maximum coefficient of thermal expansion of not greater than 1.5% at a temperature of 50° C. to 800° C., and has no heating peak when the silver powder is heated from 50° C. to 800° C. The silver powder has an ignition loss of not greater than 1.0% when the silver powder is ignited until the weight of the silver powder is constant at 800° C. The silver powder has a tap density of not less than 2 g/cm3 and a BET specific surface area of not greater than 5 m2/g.Type: ApplicationFiled: November 21, 2005Publication date: May 25, 2006Inventors: Takatoshi Fujino, Kozo Ogi