Patents by Inventor Toshihiko Ueyama

Toshihiko Ueyama 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).

  • Publication number: 20130323529
    Abstract: There is provided a bonding material capable of forming a bonding body under an inert gas atmosphere such as a nitrogen atmosphere, and capable of exhibiting a bonding strength that endures a practical use even if not a heat treatment is applied thereto at a high temperature, which is the bonding material containing silver nanoparticles coated with a fatty acid having a carbon number of 8 or less and having an average primary particle size of 1 nm or more and 200 nm or less, and silver particles having an average particle size of 0.5 ?m or more and 10 ?m or less, and an organic material having two or more carboxyl groups.
    Type: Application
    Filed: May 13, 2011
    Publication date: December 5, 2013
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Satoru Kurita, Keiichi Endoh, Yu Saito, Yutaka Hisaeda, Toshihiko Ueyama
  • Publication number: 20130270488
    Abstract: It is important that the metal particles used in a conductive paste used for wiring have the characteristic of being easily dispersed in a polar solvent in combination with another material such as a resin used in a paste. Provided is a metal particle powder which exhibits a pH value of 6 or less when 0.5 g of the metal particles to be evaluated are added to 100 mL of a potassium hydroxide solution with a pH of 11, and then an aqueous nitric acid solution in an amount in which pH becomes 5 by adding 0.10 mol/L nitric acid to 100 mL of a potassium hydroxide solution and 10 mL of ethyl alcohol (blank solution) with a pH of 11 is added.
    Type: Application
    Filed: January 18, 2012
    Publication date: October 17, 2013
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Toshihiko Ueyama, Shinya Sasaki
  • Patent number: 8486310
    Abstract: A composition containing fine silver particles which have a uniform particle size, can form a fine drawing pattern, and have a small environmental impact, a method for producing that composition, a method for producing fine silver particles, and a paste having fine silver particles are provided. The fine silver particles are produced by carrying out a fluid preparation step of preparing a reduction fluid, a silver reaction step, and a filtration/washing step. The reaction step is carried out by adding an aqueous silver nitrate fluid to a reduction fluid whose temperature has been increased to a range between 40 and 800 ° C. The aqueous silver nitrate fluid is added at a stretch. The composition containing fine silver particles is produced by dispersing the composition containing the fine silver particles in a polar fluid.
    Type: Grant
    Filed: July 20, 2011
    Date of Patent: July 16, 2013
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Yutaka Hisaeda, Toshihiko Ueyama
  • Publication number: 20130153835
    Abstract: When a substrate having a low heat resistance is used, heat treatment at approximately 120° C. at which deformation does not occur is desirable. When a low resistance is achieved regardless of the type of resin used for a conductive paste, a flexible design of a paste is possible according to purposes, and fields to which the paste could be applied are expanded. Thus, a conductive paste capable of forming a conductive film exhibiting a high conductivity even at low temperatures of approximately 120° C. regardless of whether the constituting resin is a thermosetting resin or a thermoplastic resin is provided. In a method for forming a conductive film, a conductive paste in which a dicarboxylic acid having 2 to 8 carbon atoms is added to a paste including silver nanoparticles coated with an organic substance having 2 to 6 carbon atoms, a dispersion medium, and a resin is used.
    Type: Application
    Filed: October 28, 2011
    Publication date: June 20, 2013
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Takashi Hinotsu, Yuto Hiyama, Toshihiko Ueyama
  • Publication number: 20130081759
    Abstract: Provided is a bonding material which enables formation of a bonded article in nitrogen, and can exhibit bonding strength to withstand practical use while having reduced bonding fluctuations between samples without a heat treatment procedure under pressurized or high temperature conditions. The bonding material comprises: silver nanoparticles having an average primary particle diameter of 1 to 200 nm and coated with an organic substance having 8 carbon atoms or less; a dispersion medium having a boiling point of 230° C. or higher; and a flux component including an organic matter having at least two carboxyl groups. Particularly, it is preferable to use the silver nanoparticles and submicron silver particles in combination.
    Type: Application
    Filed: June 10, 2011
    Publication date: April 4, 2013
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Keiichi Endoh, Yutaka Hisaeda, Akihiro Miyazawa, Aiko Nagahara, Toshihiko Ueyama
  • Publication number: 20130048902
    Abstract: A metal magnetic powder having a metal magnetic phase mainly composed of ferromagnetic elements, and composed of particles containing one or more kinds of elements selected from rare earth elements including Y, and Al, Si. And the method for producing the metal magnetic powder, including the steps of: eluting the non-magnetic components in the particles under an action of a reducing agent acting on the metal magnetic powder, in a solution containing a complexing agent capable of forming the complex with the non-magnetic components; and forming an oxide layer on the particles in the solution after eluting the non-magnetic components into the solution, without drying the particles.
    Type: Application
    Filed: March 31, 2011
    Publication date: February 28, 2013
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Hirohisa Omoto, Takayuki Kikuchi, Toshihiko Ueyama
  • Publication number: 20120298908
    Abstract: A hexagonal ferrite magnetic powder with a reduced amount of contaminants such as organic materials and a magnetic recording medium using the same are provided. The magnetic recording medium is formed using such a hexagonal ferrite magnetic powder that, when 0.10 mol/L nitric acid is added in an amount that changes the pH of 100 mL of a pH 11 potassium hydroxide solution (a blank solution) to 5 to a solution prepared by adding 0.05 g of the powder to 100 mL of the pH 11 potassium hydroxide solution, the pH of the resultant solution is 5 or higher.
    Type: Application
    Filed: March 29, 2011
    Publication date: November 29, 2012
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Toshihiko Ueyama, Kenji Masada
  • Publication number: 20120298009
    Abstract: A method of forming a bonded product using metal nanoparticles is provided. More specifically, provided is a paste containing a flux component that can form a metal phase even in an inert atmosphere. The use of this paste allows a bonding material that can give a practically acceptable bonding strength to be provided in an inert atmosphere such as a nitrogen atmosphere at low temperatures without performing conventionally used pressurization. The paste is a bonding material configured to include: silver nanoparticles having an average primary particle diameter of 1 to 200 nm and coated with an organic material having 8 or less carbon atoms; a flux component having at least two carboxyl groups; and a dispersion medium. The use of this bonding material allows materials to be bonded even at a temperature of 300° C. or lower.
    Type: Application
    Filed: April 23, 2010
    Publication date: November 29, 2012
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Keiichi Endoh, Yutaka Hisaeda, Akihiro Miyazawa, Aiko Nagahara, Toshihiko Ueyama
  • Patent number: 8293144
    Abstract: A composition containing fine silver particles which have a uniform particle size, can form a fine drawing pattern, and have a small environmental impact, a method for producing that composition, a method for producing fine silver particles, and a paste having fine silver particles are provided. The fine silver particles are produced by carrying out a fluid preparation step of preparing a reduction fluid, a silver reaction step, and a filtration/washing step. The reaction step is carried out by adding an aqueous silver nitrate fluid to a reduction fluid whose temperature has been increased to a range between 40 and 800° C. The aqueous silver nitrate fluid is added at a stretch. The composition containing fine silver particles is produced by dispersing the composition containing the fine silver particles in a polar fluid.
    Type: Grant
    Filed: October 23, 2008
    Date of Patent: October 23, 2012
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Yutaka Hisaeda, Toshihiko Ueyama
  • Patent number: 8293142
    Abstract: A composition containing fine silver particles which have a uniform particle size, can form a fine drawing pattern, and have a small environmental impact, a method for producing that composition, a method for producing fine silver particles, and a paste having fine silver particles are provided. The fine silver particles are produced by carrying out a fluid preparation step of preparing a reduction fluid, a silver reaction step, and a filtration/washing step. The reaction step is carried out by adding an aqueous silver nitrate fluid to a reduction fluid whose temperature has been increased to a range between 40 and 80° C. The aqueous silver nitrate fluid is added at a stretch. The composition containing fine silver particles is produced by dispersing the composition containing the fine silver particles in a polar fluid.
    Type: Grant
    Filed: July 20, 2011
    Date of Patent: October 23, 2012
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Yutaka Hisaeda, Toshihiko Ueyama
  • Publication number: 20120103515
    Abstract: In a bonding material using nanoparticles and a bonding method, use in combination with microparticles is proposed. However, there is the problem in which it is not easy to uniformly mix the nanoparticles and the microparticles. The present invention uses a bonding material including metal nanoparticles having an average particle diameter of 100 nm or less and a surface coated with an organic substance having 6 to 8 carbon atoms, and a polar solvent in an amount of 5 to 20% by mass with respect to a powder of the metal nanoparticles, and objects to be bonded with the bonding material interposed therebetween are fired at 200 to 350° C. under pressure. Thus, the metal nanoparticles are melted and returned to a bulk material, and therefore a bonding layer of the bulk material can be formed at a low temperature equal to or lower than a melting point.
    Type: Application
    Filed: October 23, 2009
    Publication date: May 3, 2012
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Keiichi Endoh, Aiko Nagahara, Yutaka Hisaeda, Toshihiko Ueyama
  • Publication number: 20110278508
    Abstract: A composition containing fine silver particles which have a uniform particle size, can form a fine drawing pattern, and have a small environmental impact, a method for producing that composition, a method for producing fine silver particles, and a paste having fine silver particles are provided. The fine silver particles are produced by carrying out a fluid preparation step of preparing a reduction fluid, a silver reaction step, and a filtration/washing step. The reaction step is carried out by adding an aqueous silver nitrate fluid to a reduction fluid whose temperature has been increased to a range between 40 and 80° C. The aqueous silver nitrate fluid is added at a stretch. The composition containing fine silver particles is produced by dispersing the composition containing the fine silver particles in a polar fluid.
    Type: Application
    Filed: July 20, 2011
    Publication date: November 17, 2011
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventors: Yutaka HISAEDA, Toshihiko Ueyama
  • Publication number: 20110272642
    Abstract: A composition containing fine silver particles which have a uniform particle size, can form a fine drawing pattern, and have a small environmental impact, a method for producing that composition, a method for producing fine silver particles, and a paste having fine silver particles are provided. The fine silver particles are produced by carrying out a fluid preparation step of preparing a reduction fluid, a silver reaction step, and a filtration/washing step. The reaction step is carried out by adding an aqueous silver nitrate fluid to a reduction fluid whose temperature has been increased to a range between 40 and 80° C. The aqueous silver nitrate fluid is added at a stretch. The composition containing fine silver particles is produced by dispersing the composition containing the fine silver particles in a polar fluid.
    Type: Application
    Filed: July 20, 2011
    Publication date: November 10, 2011
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventors: Yutaka HISAEDA, Toshihiko Ueyama
  • Publication number: 20110155968
    Abstract: A metal-containing composition that can provide, by low-temperature heat treatment, a sintered state comparable to that obtained by high-temperature heat treatment, a conductive paste, a metal film are provided. A method for manufacturing a metal-containing composition that can manufacture the metal-containing composition by simple operation steps is also provided. The metal-containing composition contains fine metal particles, and the ratio ?f of a true density ?200 to a true density ?150 (=?200/?150) is 1.10 or less where ?150 is the true density of the metal-containing composition after heating at 150° C. for 60 minutes, and ?200 is the true density after heating at 200° C. for 60 minutes. The ratio of ?150 to ?M (?150/?M) and the ratio of ?200 to ?M (?200/?M) are 0.8 or more, where ?M is the density of the fine metal particles in a bulk form. An organic material having a molecular weight of 200 or less is caused to adhere to the fine metal particles.
    Type: Application
    Filed: August 7, 2008
    Publication date: June 30, 2011
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Kosuke Iha, Yutaka Hisaeda, Toshihiko Ueyama
  • Publication number: 20110147642
    Abstract: A magnetic powder for magnetic recording medium comprises acicular particles constituted primarily of Fe, wherein the powder contains Co in an amount such that the Co/Fe ratio is 50 at. % or less and the Co is contained in a manner such that the surface portion has a higher concentration than the core portion of the particles, and upon subjecting the magnetic powder for magnetic recording medium to TG measurement, the powder exhibits at least two oxidation starting points: a low-temperature side oxidation starting point and a high-temperature side oxidation starting point. The magnetic powder achieves improved resistance to oxidation without sacrificing magnetic characteristics.
    Type: Application
    Filed: March 3, 2011
    Publication date: June 23, 2011
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shinichi KONNO, Kenichi INUOE, Toshihiko UEYAMA, Kenji MASADA, Shinya SASAKI
  • Publication number: 20100243967
    Abstract: A composition containing fine silver particles which have a uniform particle size, can form a fine drawing pattern, and have a small environmental impact, a method for producing that composition, a method for producing fine silver particles, and a paste having fine silver particles are provided. The fine silver particles are produced by carrying out a fluid preparation step of preparing a reduction fluid, a silver reaction step, and a filtration/washing step. The reaction step is carried out by adding an aqueous silver nitrate fluid to a reduction fluid whose temperature has been increased to a range between 40 and 80° C. The aqueous silver nitrate fluid is added at a stretch. The composition containing fine silver particles is produced by dispersing the composition containing the fine silver particles in a polar fluid.
    Type: Application
    Filed: October 23, 2008
    Publication date: September 30, 2010
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Yutaka Hisaeda, Toshihiko Ueyama
  • Patent number: 7763352
    Abstract: A magnetic powder is provided composed of particles having a balanced shape and distribution, the particles having a small, uniform volume, making it possible to achieve improved density and reliability of a coating type magnetic recording medium. The magnetic powder has Fe as a main component, and is comprised of particles having a cross-section perpendicular to the particle major axis that is substantially round or elliptical, wherein a standard geometrical deviation indicating the variation in cross-sectional area thereof is within the range of 1.01 to 3.0. The invention is also directed to a magnetic powder in which the standard geometrical deviation indicating the variation in the particle volume is within the range of 1.01 to 4.0, and the standard geometrical deviation indicating variation in the flat acicularity is within 1.01 to 2.0.
    Type: Grant
    Filed: September 14, 2006
    Date of Patent: July 27, 2010
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Yoshiyuki Shoji, Toshihiko Ueyama
  • Patent number: 7641990
    Abstract: Non-magnetic powder of particles for non-magnetic lower layer applications is provided that enables a multilayer coating type magnetic recording medium having good surface smoothness to be obtained. The particles are iron compound particles having a long axis with a standard geometrical deviation, as obtained from a transmission electron microscope image, that is greater than 1.5, and a short axis with a standard geometrical deviation, as obtained from a TEM image, that is greater than 1.35. The iron compound particles may be hematite or iron oxyhydroxide.
    Type: Grant
    Filed: June 23, 2006
    Date of Patent: January 5, 2010
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Shinichi Konno, Toshihiko Ueyama, Kenichi Inoue, Takayuki Yoshida, Ken Inoue
  • Patent number: 7473469
    Abstract: A ferromagnetic metal powder for a magnetic recording medium that combines good magnetic properties and oxidation stability, and a magnetic recording medium using the powder. A method of producing the magnetic powder comprises using oxygen to form an oxide film, then changing the state of the oxide film by using moderate gas phase activation treatment in an active gas, using, for example, CO or H2 or other such gas having reducing properties. ESCA-based measurements show that the binding energy peak of the powder is more to the low energy side compared to when the above treatment is not used, showing that the oxide film has oxidation resistance. The storage stability of a magnetic recording medium is improved by using the powder.
    Type: Grant
    Filed: December 23, 2005
    Date of Patent: January 6, 2009
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Shinichi Konno, Kenichi Inoue, Toshihiko Ueyama
  • Patent number: 7357980
    Abstract: A nonmagnetic powder, used for the nonmagnetic layer of a coated type magnetic recording medium having a multilayer structure, has good dispersibility in the binder in which it is dispersed to prepare a coating material that is applied to the nonmagnetic layer. The nonmagnetic powder has an iron compound as its principal component and exhibits a maximum pore volume value in a pore diameter range of 0.01 ?m to 0.05 ?m within a pore diameter range of 0.0018 ?m to 0.1 ?m in which the relationship between pore diameter and pore volume is calculated by a mercury injection method. The nonmagnetic powder exhibits a cumulative pore volume value in a pore diameter range of 0.0018 ?m to 0.01 ?m that is not more than 30% of the cumulative pore volume value in the pore diameter range of 0.0018 ?m to 0.1 ?m.
    Type: Grant
    Filed: August 19, 2005
    Date of Patent: April 15, 2008
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Shinichi Konno, Kenichi Inoue, Toshihiko Ueyama, Ken Inoue