Patents Assigned to Dowa Electronics Materials Co., Ltd.
  • Carrier core material
    Patent number: 10185238
    Abstract: A carrier core material is provided that is formed with ferrite particles which can uniformly adhere a coupling agent to the entire surface. A carrier core material is formed with ferrite particles, and the powder pH of the ferrite particles is equal to or more than 9. Here, the ferrite particles are preferably formed of Mn ferrite or Mn—Mg ferrite. The ferrite particles preferably contain 45 wt % or more but 65 wt % or less of Fe, 15 wt % or more but 30 wt % or less of Mn and 5 wt % or less of Mg.
    Type: Grant
    Filed: July 21, 2017
    Date of Patent: January 22, 2019
    Assignees: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA IP CREATION CO., LTD.
    Inventors: Yuto Kamai, Shinya Sasaki
  • SILVER ALLOY POWDER AND METHOD FOR PRODUCING SAME
    Publication number: 20190009341
    Abstract: While a molten metal obtained by melting silver and a metal, which is selected from the group consisting of tin, zinc, lead and indium, in an atmosphere of nitrogen is allowed to drop, a high-pressure water (preferably pure water or alkaline water) is sprayed onto the molten metal in the atmosphere or an atmosphere of nitrogen to rapidly cool and solidify the molten metal to produce a silver alloy powder which comprises silver and the metal which is selected from the group consisting of tin, zinc, lead and indium and which has an average particle diameter of 0.5 to 20 ?m, the silver alloy powder having a temperature of not higher than 300° C. at a shrinking percentage of 0.5%, a temperature of not higher than 400° C. at a shrinking percentage of 1.0% and a temperature of not higher than 450° C. at a shrinking percentage of 1.5% in a thermomechanical analysis.
    Type: Application
    Filed: December 26, 2016
    Publication date: January 10, 2019
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Masahiro YOSHIDA, Yoshiyuki MICHIAKI, Kenichi INOUE
  • GROUP III NITRIDE SEMICONDUCTOR LIGHT-EMITTING ELEMENT AND METHOD OF MANUFACTURING SAME
    Publication number: 20190006558
    Abstract: A group III nitride semiconductor light-emitting element having longer element life than conventional group III nitride semiconductor light-emitting elements and a method of manufacturing the same are provided. A group III nitride semiconductor light-emitting element 100 comprises, in the following order: an n-type group III nitride semiconductor layer 30; a group III nitride semiconductor laminated body 40 obtained by alternately laminating a barrier layer 40a and a well layer 40b narrower in bandgap than the barrier layer 40a in the stated order so that the number of barrier layers 40a and the number of well layers 40b are both N, where N is an integer; an AlN guide layer 60; and a p-type group III nitride semiconductor layer 70, wherein the AlN guide layer 60 has a thickness of 0.5 nm or more and 2.0 nm or less.
    Type: Application
    Filed: June 22, 2016
    Publication date: January 3, 2019
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventors: Yasuhiro WATANABE, Takehiko FUJITA
  • Silver powder and method for producing same
    Patent number: 10170213
    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: January 2, 2018
    Date of Patent: January 1, 2019
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Yoshiyuki Michiaki, Hiroshi Kamiga
  • ORIENTED BODY, METHOD FOR PRODUCING THE SAME, DEVICE FOR PRODUCING THE SAME, AND MAGNETIC RECORDING MEDIUM
    Publication number: 20180366151
    Abstract: There is provided an oriented body containing platinum group-substituted-6 iron oxide particles typified by Rh-substituted ?-iron oxide or Ru-substituted ?-iron oxide applicable to MAMR, MIMR, or F-MIMR system, and a technique related thereto, containing platinum group element-substituted ?-iron oxide particles in which a part of ?-iron oxide is substituted with at least one element of platinum group elements, as magnetic particles wherein the degree of orientation of the magnetic particles defined by the degree of orientation=SQ (direction of magnetization easy-axes)/SQ (direction of magnetization hard-axes) exceeds 5.0, and a coercive force exceeds 31 kOe.
    Type: Application
    Filed: November 30, 2016
    Publication date: December 20, 2018
    Applicants: THE UNIVERSITY OF TOKYO, DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shin-ichi OHKOSHI, Kenta IMOTO, Shizuka ANAN, Asuka NAMAI, Kenji MASADA
  • Method of producing III nitride semiconductor light-emitting device
    Patent number: 10147842
    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: Grant
    Filed: December 8, 2015
    Date of Patent: December 4, 2018
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventors: Takehiko Fujita, Yasuhiro Watanabe
  • SILVER POWDER AND METHOD FOR PRODUCING SAME
    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
  • Magnetic iron oxide nanopowder and process for producing the same
    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
  • Carrier core material and electrophotographic development carrier using same and electrophotographic developer
    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
  • Bonding method using bonding material
    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
  • SILVER-COATED COPPER POWDER AND METHOD FOR PRODUCING SAME
    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
  • METHOD OF PRODUCING N-TYPE OHMIC ELECTRODE AND N-TYPE OHMIC ELECTRODE, N-TYPE ELECTRODE, AND III NITRIDE SEMICONDUCTOR LIGHT-EMITTING DEVICE
    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
  • FERRITE POWDER FOR BONDED MAGNETS, METHOD FOR PRODUCING THE SAME AND FERRITE BONDED MAGNET
    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
  • PHOSPHORUS-CONTAINING COPPER POWDER AND METHOD FOR PRODUCING THE SAME
    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
  • Method of producing III nitride semiconductor light-emitting device and III nitride semiconductor light-emitting device
    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
  • Silver-coated copper alloy powder and method for producing same
    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
  • MAGNETIC COMPOUND AND ANTENNA
    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
  • FINE SILVER PARTICLE DISPERSING SOLUTION
    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
  • Bonding material and bonding method using the same
    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
  • EPSILON IRON OXIDE AND METHOD FOR PRODUCING THE SAME, MAGNETIC COATING MATERIAL AND MAGNETIC RECORDING MEDIUM
    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