Patents Assigned to Dowa Electronics Materials Co., Ltd.
  • Publication number: 20180326497
    Abstract: There is provided a silver powder which has a small average particle diameter and a small thermal shrinkage percentage, and a method for producing the same. While a molten metal of silver heated to a temperature (1292 to 1692° C.), which is higher than the melting point (962° C.) of silver by 330 to 730° C., is allowed to drop, a high-pressure water is sprayed onto the molten metal of silver (preferably at a water pressure of 90 to 160 MPa) to rapidly cool and solidify the molten metal of silver to powderize silver to produce a silver powder which has an average particle diameter of 1 to 6 ?m and a shrinkage percentage of not greater than 8% (preferably not greater than 7%) at 500° C., the product of the average particle diameter by the shrinkage percentage at 500° C. being 1 to 11 ?m·% (preferably 1.5 to 10.5 ?m·%).
    Type: Application
    Filed: October 26, 2016
    Publication date: November 15, 2018
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Atsushi Ebara, Kenichi Inoue, Yoshiyuki Michiaki, Takahiro Yamada, Masahiro Yoshida
  • Patent number: 10099941
    Abstract: A magnetic ?-form iron oxide nanopowder is a novel magnetic iron oxide nanopowder having magnetic polarization and spontaneous electric polarization and having physical properties similar to those of half-metals; and a process produces the magnetic nanopowder. The magnetic powder has a composition represented by Fe2O3 and has a crystal structure belonging to the monoclinic system.
    Type: Grant
    Filed: June 18, 2015
    Date of Patent: October 16, 2018
    Assignees: THE UNIVERSITY OF TOKYO, DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shin-ichi Ohkoshi, Marie Yoshikiyo, Asuka Namai, Hiroko Tokoro, Waka Tarora, Tomomichi Nasu, Takayuki Yoshida, Manabu Tanaka
  • Patent number: 10090275
    Abstract: A method of bonding two different substances includes the steps of: applying a bonding material containing a flux component that includes an organic material having at least two carboxyl groups to a bonding surface of a bonding object, disposing an object to be bonded on the bonding material, performing preliminary firing at a preset temperature in a state in which the object to be bonded is disposed, and performing a main firing by heating at a temperature higher than the temperature of the preliminary firing.
    Type: Grant
    Filed: December 11, 2015
    Date of Patent: October 2, 2018
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Keiichi Endoh, Yutaka Hisaeda, Akihiro Miyazawa, Aiko Hirata, Toshihiko Ueyama
  • Patent number: 10088764
    Abstract: A carrier core material includes, a main component, a material represented by a composition formula MnXMYFe3?(X+Y)O4 (where M is selected from Mg, Ti, Cu, Zn and Ni, 0<X, 0?Y, 0<X+Y<1), in which 0.1 to 1.0 mol % of at least one of Sr element and Ca element is contained as the total amount by conversion to SrO or CaO and in which the frequency of a grain whose length RSm is equal or more than 8.0 ?m among grains appearing on the surface of particles of the carrier core material is equal to or less than 2.0 number percent. In this way, the degradation of a carrier caused by long-term use such as the separation of a coating resin is significantly reduced, stable charging performance is maintained and the cracking or chipping of the particles is reduced.
    Type: Grant
    Filed: March 22, 2016
    Date of Patent: October 2, 2018
    Assignees: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA IP CREATION CO., LTD.
    Inventors: Yuto Kamai, Takeshi Kawauchi
  • Publication number: 20180272425
    Abstract: A silver-coated copper powder obtained by coating the surface of a copper powder, which is obtained by the atomizing method or the like, with 5 wt % or more (with respect to the silver-coated copper powder) of a silver containing layer of silver or a silver compound, is added to a silver supporting solution of a potassium silver cyanide solution (or a potassium silver cyanide solution containing at least one selected from the group consisting of potassium pyrophosphate, boric acid, tripotassium citrate monohydrate, anhydrous citric acid and L-aspartic acid) to cause 0.01 wt % or more (with respect to the silver-coated copper powder) of silver to be supported on the surface of the copper powder coated with the silver containing layer.
    Type: Application
    Filed: January 6, 2016
    Publication date: September 27, 2018
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Noriaki Nogami, Hiroshi Kamiga
  • Publication number: 20180243831
    Abstract: An object of the present invention is to provide a phosphorus-containing copper powder with good volume resistivity and a small carbon content by suppressing an oxygen content to a relatively low value even if a particle size is made small, and a method for producing the same. In the phosphorus-containing copper powder containing phosphorus, a ratio of an oxygen content (wt. %) to a BET specific surface area (m2/g) (oxygen content/BET specific surface area) is 0.90 wt. %·g/m2 or less, a divalent copper compound is present on a surface of particles constituting the phosphorus-containing copper powder, a carbon content is 0.10 wt. % or less, and D50 is 7.11 ?m or less.
    Type: Application
    Filed: August 18, 2016
    Publication date: August 30, 2018
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Kenichi INOUE, Atsushi EBARA, Masahiro YOSHIDA, Kyoso MASUDA, Takahiro YAMADA, Shinichi UCHIYAMA
  • Publication number: 20180248080
    Abstract: Provided is a method of producing an n-type ohmic electrode that can form a good ohmic contact with an n-type AlxGa1?xN (0.5?x?1) layer. The method of producing an n-type ohmic electrode includes: a first step of forming a first layer 11 made of one of Ti and Hf on a surface of a layer 30; a second step of forming a second layer 12 made of Sn on the surface of the first layer 11; a third step of forming a third layer 13 made of one of V and Mo on the surface of the second layer 12; a fourth step of forming a fourth layer 14 made of Al on the surface of the third layer 13; and a fifth step of performing heat treatment on the first layer 11, the second layer 12, the third layer 13, and the fourth layer 14.
    Type: Application
    Filed: September 2, 2016
    Publication date: August 30, 2018
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventor: Tatsunori TOYOTA
  • Publication number: 20180244537
    Abstract: A ferrite powder for bonded magnets capable of producing a ferrite bonded magnet having a BHmax value of 2.65 MGOe or more when molded in a magnetic field and a method for producing the same, and a ferrite bonded magnet using the same, wherein a compression density is 3.50 g/cm3 or more, and an average value of a (long axis length/short axis length) ratio of ferrite particles having a long axis length of 1.0 ?m or more is, 1.60 or less.
    Type: Application
    Filed: February 23, 2016
    Publication date: August 30, 2018
    Applicants: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA F-TEC CO., LTD.
    Inventors: Tomoya YAMADA, Satoru TSUBOI, Keisuke AYABE, Yasunobu MISHIMA, Masayasu SENDA
  • Patent number: 10062473
    Abstract: 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: Grant
    Filed: January 15, 2013
    Date of Patent: August 28, 2018
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Kenichi Inoue, Kozo Ogi, Atsushi Ebara, Yuto Hiyama, Takahiro Yamada, Toshihiko Ueyama
  • Patent number: 10062806
    Abstract: We propose a method of producing a III nitride semiconductor light-emitting device including a p-type semiconductor layer, in which the p-type semiconductor layer is formed by the steps comprising: an electron blocking layer formation step for forming an electron blocking layer made of AlyGa1-yN (b<y?1) on a light emitting layer; and a p-type contact formation step for forming a p-type contact layer which is AlxGa1-xN (0?x?0.1), directly on the electron blocking layer, and in which the electron blocking layer formation step is performed using a carrier gas containing hydrogen as a main component, and the p-type contact formation step is performed using a carrier gas containing nitrogen as a main component.
    Type: Grant
    Filed: December 7, 2015
    Date of Patent: August 28, 2018
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventors: Takehiko Fujita, Yasuhiro Watanabe
  • Publication number: 20180218814
    Abstract: An object is to provide a magnetic compound excellent in high frequency properties and excellent in mechanical strength, and its related items, using the polyarylene sulfide resin, and to provide a technique regarding the magnetic compound having a metal magnetic powder and a polyarylene sulfide resin, and satisfying both mechanical strength and high frequency properties.
    Type: Application
    Filed: June 1, 2016
    Publication date: August 2, 2018
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Takayuki YOSHIDA, Masahiro GOTOH, Toshihiko UEYAMA, Takuyuki BABA, Toru SUZUKI, Koji TANAKA
  • Publication number: 20180179409
    Abstract: There is produced a fine silver particle dispersing solution which contains: fine silver particles (the content of silver in the fine silver particle dispersing solution being 30 to 95% by weight), which have an average primary particle diameter of greater than 100 nm and not greater than 300 nm and which are coated with an amine having a carbon number of 8 to 12, such as octylamine, serving as an organic protective material; a polar solvent (5 to 70% by weight) having a boiling point of 150 to 300° C.; and an acrylic dispersing agent (5% by weight or less with respect to the fine silver particles), such as a dispersing agent of at least one of acrylic acid ester and methacrylic acid ester.
    Type: Application
    Filed: April 22, 2016
    Publication date: June 28, 2018
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shingo Teragawa, Takashi Hinotsu, Taro Torigoe, Shinichi Konno
  • Patent number: 10008471
    Abstract: A bonded product is obtained by applying a silver paste containing silver nanoparticles having an average primary particle diameter of 1 to 200 nm, and performing firing. A diameter of a crystallite of the bonded product on a (111) plane of Ag when heated at 250° C. for 10 minutes in an inert atmosphere is 65 nm or larger.
    Type: Grant
    Filed: December 11, 2015
    Date of Patent: June 26, 2018
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Keiichi Endoh, Yutaka Hisaeda, Akihiro Miyazawa, Aiko Hirata, Toshihiko Ueyama
  • Publication number: 20180170767
    Abstract: An epsilon iron oxide has an average particle size of 10 to 18 nm, a part of the iron element being substituted with a substitutional element and has a coercive force of 14 kOe or less, wherein a coefficient of variation of the particle size is 40% or less. A method for producing the same, a magnetic coating material and a magnetic recording medium using the epsilon iron oxide, includes depositing a metal compound of a substitutional element on iron oxide hydroxide to thereby obtain iron oxide hydroxide on which the metal compound is deposited; coating the iron oxide hydroxide on which the metal compound is deposited, with silicon oxide to thereby obtain iron oxide hydroxide coated with the silicon oxide; and applying heat treatment to the silicon oxide-coated iron oxide hydroxide in an oxidizing atmosphere, wherein a part of an iron element is substituted with the substitutional element.
    Type: Application
    Filed: June 13, 2016
    Publication date: June 21, 2018
    Applicants: THE UNIVERSITY OF TOKYO, DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shin-ichi OHKOSHI, Syunsuke OKA, Asuka NAMAI, Kenji MASADA
  • Publication number: 20180166604
    Abstract: We propose a method of producing a III nitride semiconductor light-emitting device 1 having a p-type semiconductor layer 150 in this order, wherein the p-type semiconductor layer 150 is formed by the steps comprising: an electron blocking layer formation step for forming an electron blocking layer 51 having an Al content higher than that of the barrier layer 42, on the light emitting layer 40; a nitrogen carrier gas supply step for supplying at least a carrier gas containing nitrogen as a main component to a surface of the electron blocking layer 51; and a second p-type contact formation step for forming a second p-type contact layer 55 made of AlyGa1-yN on the electron blocking layer 51 after the nitrogen carrier gas supply step, and wherein the second p-type contact formation step is performed using a carrier gas containing hydrogen as a main component.
    Type: Application
    Filed: December 8, 2015
    Publication date: June 14, 2018
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventors: Takehiko FUJITA, Yasuhiro WATANABE
  • Patent number: 9993871
    Abstract: A silver powder, including: an organic substance on a surface of the silver powder, the organic substance containing at least one carboxyl group and at least one hydroxyl group in one molecule of the organic substance, wherein a BET specific surface area of the silver powder is 0.1 m2/g or more but 2.0 m2/g or less, and wherein a cumulative 50% point of particle diameter (D50) of the silver powder in a volume-based particle size distribution of the silver powder as measured by a laser diffraction particle size distribution analysis is 0.1 ?m or more but 6.0 ?m or less, and a ratio of [(D90?D10)/D50] is 3.0 or less, where D50 is the cumulative 50% point of particle diameter, D90 is a cumulative 90% point of particle diameter of the silver powder, and D10 is a cumulative 10% point of particle diameter of the silver powder.
    Type: Grant
    Filed: July 27, 2015
    Date of Patent: June 12, 2018
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventors: Taro Nakanoya, Hiroshi Kamiga
  • Publication number: 20180158564
    Abstract: There is provided a silver powder, which is able to obtain a conductive paste having a high thixotropic ratio and a high Casson yield value and which is able to form a conductive pattern having a low resistance, and a method for producing the same. An aliphatic amine such as hexadecylamine is added to a silver powder, the surface of which is coated with a fatty acid such as stearic acid, to be stirred and mixed to form the aliphatic amine on the outermost surface of the silver powder while allowing the fatty acid to react with the aliphatic amine to form an aliphatic amide such as hexadecanamide between the fatty acid and the aliphatic amine.
    Type: Application
    Filed: January 2, 2018
    Publication date: June 7, 2018
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Yoshiyuki Michiaki, Hiroshi Kamiga
  • Publication number: 20180151279
    Abstract: A magnetic compound having a small dielectric loss and an antenna constituted by the magnetic compound and an electronic device incorporating the antenna are provided by a metal magnetic powder which is well dispersed in a resin having small dielectric loss, and a magnetic powder composite including: a metal magnetic powder; and one or more elements selected from carboxylic acid or its anhydride, aromatic carboxylic acid ester, and a derivative thereof, having a property that real part ?? permeability is 1.45 or more, tan ?? is 0.1 or less, tan ?? is 0.05 or less at a measuring frequency of 2 GHz, when a magnetic powder composite is prepared by adding 5 parts by mass of one or more elements selected from the carboxylic acid or its anhydride, the aromatic carboxylic acid ester, and the derivative thereof to 100 parts by mass of the metal magnetic powder.
    Type: Application
    Filed: June 1, 2016
    Publication date: May 31, 2018
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Toshihiko UEYAMA, Masahiro GOTOH, Takayuki YOSHIDA, Takuyuki BABA
  • Patent number: 9984788
    Abstract: There is provided a silver powder, which is able to obtain a conductive paste having a high thixotropic ratio and a high Casson yield value and which is able to form a conductive pattern having a low resistance, and a method for producing the same. An aliphatic amine such as hexadecylamine is added to a silver powder, the surface of which is coated with a fatty acid such as stearic acid, to be stirred and mixed to form the aliphatic amine on the outermost surface of the silver powder while allowing the fatty acid to react with the aliphatic amine to form an aliphatic amide such as hexadecanamide between the fatty acid and the aliphatic amine.
    Type: Grant
    Filed: July 24, 2015
    Date of Patent: May 29, 2018
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Yoshiyuki Michiaki, Hiroshi Kamiga
  • Patent number: 9964878
    Abstract: A carrier core material is represented by a composition formula MxFe3-xO4 (where M is Mn and/or Mg, and X is a total of Mn and Mg and is a substitution number of Fe by Mn and Mg, 0<X?1), in which 5 to 20 number percent of bound particles where 2 to 5 spherical particles are bound together are contained and in which the maximum peak-to-trough depth Rz of the surface of normal spherical particles other than the bound particles is equal to or more than 1.5 ?m but equal to or less than 2.1 ?m. In this way, it is possible to increase the amount of toner supplied to a development region, and the surface of a photosensitive member is prevented from being scratched by a magnetic brush.
    Type: Grant
    Filed: March 1, 2016
    Date of Patent: May 8, 2018
    Assignees: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA IP CREATION CO., LTD.
    Inventors: Yohei Ishikawa, Shinya Sasaki