Patents Assigned to Shoei Chemical Inc.
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Patent number: 6841495Abstract: A glass containing no lead and comprising, calculated as oxides: 40-60 wt. % ZnO, 15-35 wt. % B2O3, 1-16 wt. % SiO2, 1-10 wt. % Al2O3, 2-15 wt. % MnO2, and at least one selected from the group consisting of Li2O, Na2O and K2O in their total of 0.5-10 wt. %, and a glass with the above-described components where a total of at least one selected from the group consisting of Li2O, Na2O and K2O is 0-5 wt. %, and at least one selected from the group consisting of MgO, CaO, TiO2, Cr2O3, ZrO2, Ta2O5, SnO2, and Fe2O3 is further included in their total of 0.1-5 wt. %. A conductive paste using such a glass as an inorganic binder has a superior binder removal ability and a good sinterability and can form dense conductors with excellent characteristics with respect to resistance to plating solutions, adhesive strength, resistance to thermal shocks, etc.Type: GrantFiled: December 9, 2002Date of Patent: January 11, 2005Assignee: Shoei Chemical Inc.Inventors: Tetsuya Tanaka, Nobuko Morinaga, Yuko Koyama, Yoshiko Morinaga, Mikio Yamazoe, Megumi Kawahara, Kenji Morinaga
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Patent number: 6793842Abstract: A ferrite fine powder having a mean particle size of 0.1 to 30 &mgr;m and made of spherical single-crystal particles. The ferrite fine powder has superior physical properties and excellent magnetic properties desirable for use as a raw material for a dust core of coils, transformers, etc. The powder is prepared by forming a solution or suspension containing a compound or compounds of at least one of the metals forming the ferrite into fine droplets, and thermally decomposing the droplets at elevated temperatures.Type: GrantFiled: July 6, 2001Date of Patent: September 21, 2004Assignees: Shoei Chemical Inc., TDK CorporationInventors: Yuji Akimoto, Kazuro Nagashima, Masahiro Ikemoto, Minoru Takaya, Yoshiaki Akachi, Hisashi Kobuke
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Publication number: 20030131687Abstract: A method for preparing a highly crystallized metal powder, comprising: supplying at least one heat-decomposable metal compound powder into a reaction vessel using a carrier gas; and forming a metal powder by heating the metal compound powder in a state in which the metal compound powder is dispersed in a gas phase at a concentration of no more than 10 g/liter, at a temperature that is over the decomposition temperature of the metal compound powder and at least (Tm−200)° C. when the melting point of the metal contained in the metal compound powder is Tm° C. The method provides a high-purity, high-density, highly dispersible, fine, highly crystallized metal powder consisting of spherical particles of uniform size, which is suited to use in thick film pastes, and particularly conductor pastes and the like used in the preparation of multilayer ceramic electronic parts.Type: ApplicationFiled: January 14, 2003Publication date: July 17, 2003Applicant: Shoei Chemical Inc.Inventors: Yuji Akimoto, Kazuro Nagashima, Hiroshi Yoshida, Hirotaka Takushima, Masayuki Maekawa
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Patent number: 6551527Abstract: A conductive paste comprising a conductive powder, an organic binder and a solvent as principal components, wherein the paste also contains at least one selected from the group consisting of N-acylamino acids and salts thereof. The conductive paste has a greatly improved storability without causing separating out or precipitation of the conductive powder even after storing for a prolonged period of time.Type: GrantFiled: August 6, 2001Date of Patent: April 22, 2003Assignee: Shoei Chemical Inc.Inventors: Hiroshi Yoshida, Takashi Endo, Miyuki Mori
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Patent number: 6530972Abstract: A method for preparing a highly crystallized metal powder, involving the steps of: supplying at least one heat-decomposable metal compound powder into a reaction vessel using a carrier gas; and forming a metal powder by heating the metal compound powder in a state in which the metal compound powder is dispersed in a gas phase at a concentration of no more than 10 g/liter, at a temperature that is over the decomposition temperature of the metal compound powder and at least (Tm −200)° C. when the melting point of the metal contained in the metal compound powder is Tm° C. The method provides a high-purity, high-density, highly dispersible, fine, highly crystallized metal powder consisting of spherical particles of uniform size, which is suitable for use in thick film pastes, and particularly conductor pastes and the like used in the preparation of multilayer ceramic electronic parts.Type: GrantFiled: April 17, 2001Date of Patent: March 11, 2003Assignee: Shoei Chemical Inc.Inventors: Yuji Akimoto, Kazuro Nagashima, Hiroshi Yoshida, Hirotaka Takushima, Masayuki Maekawa
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Patent number: 6528166Abstract: Nickel composite particles having a layer of a nickel-containing spinel on at least a part of the surface of nickel particles, or nickel composite particles having an oxide layer of metals other than nickel on at least a part of the surface of nickel particles and a layer of a nickel-containing spinel at an interface between the nickel particles and the metal oxide layer. The nickel composite particles are produced by forming fine liquid droplets from a solution containing (a) at least one thermally decomposable nickel compound and (b) at least one thermally decomposable metal compound capable of forming a spinel together with nickel; and heating the liquid droplets at a temperature higher than the decomposition temperatures of the compound (a) and (b) to nickel particles and simultaneously deposit a nickel-containing spinel layer, or further a metal oxide layer on the spinel layer.Type: GrantFiled: November 15, 2001Date of Patent: March 4, 2003Assignee: Shoei Chemical Inc.Inventors: Yuji Akimoto, Kazuro Nagashima, Hiroshi Yoshida, Yiyi Ma
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Publication number: 20020114950Abstract: Nickel composite particles having a layer of a nickel-containing spinel on at least a part of the surface of nickel particles, or nickel composite particles having an oxide layer of metals other than nickel on at least a part of the surface of nickel particles and a layer of a nickel-containing spinel at an interface between the nickel particles and the metal oxide layer. The nickel composite particles are produced by forming fine liquid droplets from a solution containing (a) at least one thermally decomposable nickel compound and (b) at least one thermally decomposable metal compound capable of forming a spinel together with nickel; and heating the liquid droplets at a temperature higher than the decomposition temperatures of the compound (a) and (b) to nickel particles and simultaneously deposit a nickel-containing spinel layer, or further a metal oxide layer on the spinel layer.Type: ApplicationFiled: November 15, 2001Publication date: August 22, 2002Applicant: SHOEI CHEMICAL INC.Inventors: Yuji Akimoto, Kazuro Nagashima, Hiroshi Yoshida, Yiyi Ma
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Patent number: 6403218Abstract: Nickel composite particles having a layer of a nickel-containing spinel on at least a part of the surface of nickel particles, or nickel composite particles having an oxide layer of a metal other than nickel on at least a part of the surface of nickel particles and a layer of a nickel-containing spinel at an interface between the nickel particles and the metal oxide layer. The nickel composite particles are produced by forming fine liquid droplets from a solution containing (a) at least one thermally decomposable nickel compound and (b) at least one thermally decomposable metal compound capable of forming a spinel together with nickel; and heating the liquid droplets at a temperature higher than the decomposition temperatures of compounds (a) and (b) to form nickel particles and simultaneously deposit a nickel-containing spinel layer, or further, a metal oxide layer on the spinel layer.Type: GrantFiled: September 17, 1999Date of Patent: June 11, 2002Assignee: Shoei Chemical Inc.Inventors: Yuji Akimoto, Kazuro Nagashima, Hiroshi Yoshida, Yiyi Ma
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Patent number: 6060165Abstract: A metal powder having a vitreous thin layer on at least a part of the surface thereof wherein the amount of the vitreous thin layer is preferably 0.01 to 50% by weight based on the metal powder without the vitreous thin layer. The metal powder is prepared by a process comprising the steps of: bringing a solution comprising a heat-decomposable metal compound to fine droplets; and heating the droplets to a temperature above the decomposition temperature of the metal compound, wherein a precursor of an oxide, heat-decomposable to produce a vitreous material which, together with the metal, does not form a solid solution, is added to the solution and the vitreous material is deposited, upon the heating, in the vicinity of the surface of the metal powder. The powder is useful for the preparation of a thick film paste used in a multilayer ceramic electronic component or substrate, since it has an excellent oxidation resistance during storage, in a conductor paste, and during firing of the paste.Type: GrantFiled: September 23, 1997Date of Patent: May 9, 2000Assignee: Shoei Chemical Inc.Inventors: Eiichi Asada, Yuji Akimoto, Fumiyuki Shimizu, Kazuro Nagashima
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Patent number: 6040055Abstract: Disclosed is an improved surface discharge element comprising a dielectric substrate having a discharge electrode on one surface and an inductive electrode on the other surface of the substrate, at least said discharge electrode being of a thick film conductor including conductive powder and lead-free glass as main constituents. The lead-free discharge electrode is physically resistive to erosion by electric discharge, and accordingly it can have an elongated life in use.Type: GrantFiled: June 4, 1997Date of Patent: March 21, 2000Assignee: Densoken Co., Ltd. & Shoei Chemical Inc.Inventors: Seiji Baba, Takashi Endo
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Patent number: 6007743Abstract: A nickel powder having at at least part of the surface thereof a layer of a composite oxide represented by the formula: A.sub.x B.sub.y O.sub.(x+2y), wherein A stands for at least one element selected from the group consisting of Ca, Sr and Ba; B stands for at least one element selected from the group consisting of Ti and Zr; and x and y represent numbers satisfying the formula: 0.5.ltoreq.y/x.ltoreq.4.5). The nickel powder may further contains at least one selected from among boron oxide, aluminum oxide and silicon oxide. The nickel powder is produced by spray pyrolyzing a solution of thermal decomposable starting compounds of nickel and additive elements and the resultant powder is suitable for use in a thick-film conductor paste having a sintering-starting temperature close to that of ceramic layers and a shrinkage behavior close to that of a ceramic without detriment to the conductivity and electric properties thereof.Type: GrantFiled: February 17, 1998Date of Patent: December 28, 1999Assignee: Shoei Chemical, Inc.Inventors: Eiichi Asada, Yuji Akimoto, Kazuro Nagashima, Hiroshi Yoshida, Yiyi Ma
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Patent number: 5964918Abstract: A process for preparing a metal powder, comprising the steps of: bringing a solution comprising at least one metal salt to fine droplets; and heating the droplets to a temperature above the decomposition temperature of the metal salt, wherein at least one compound which is heat-decomposable to produce a metal, a semimetal or an oxide of the metal or semimetal capable of remaining unmelted upon heating at the heat temperature is added to the solution and at least one selected from the group consisting of the metal, semimetal and oxide is heat-segregated in the vicinity of the surface of the metal powder. The resultant metal powder has a uniform particle size and good dispersibility without fusing or aggregation and is useful for the preparation of thick film pastes used in electronic circuits or components.Type: GrantFiled: September 23, 1997Date of Patent: October 12, 1999Assignee: Shoei Chemical Inc.Inventors: Eiichi Asada, Yuji Akimoto, Kazuro Nagashima, Mineto Iwasaki
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Patent number: 5871840Abstract: A nickel powder having a composite oxide layer comprising lanthanum and nickel and, optionally an oxide of chromium, on at least a part of the surface thereof. The nickel powder is produced by a process comprising the steps of: bringing a solution comprising at least one heat-decomposable nickel compound and at least one heat-decomposable lanthanum compound and, optionally, at least one heat-decomposable chromium compound, to fine droplets; and heating the droplets at a temperature above the decomposition temperatures of these compounds to prepare a nickel powder and, at the same time, to deposit a composite oxide layer comprising lanthanum and nickel and, when present, chromium oxide, in the vicinity of the surface of the nickel powder.Type: GrantFiled: September 23, 1997Date of Patent: February 16, 1999Assignee: Shoei Chemical Inc.Inventors: Eiichi Asada, Yuji Akimoto, Kazuro Nagashima
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Patent number: 5763339Abstract: A lead-free insulating glass composition comprises (A) 50 to 85 wt. % of a glass comprising, on a weight basis, 28 to 38% of SiO.sub.2, 4 to 10% of B.sub.2 O.sub.3, 8 to 16% of Al.sub.2 O.sub.3, 15 to 23% of MgO, 1 to 12% of CaO, 3 to 9% of BaO, 8 to 16% of ZnO, and 3 to 8% of ZrO.sub.2 ; and (B) 50 to 15 wt. % of at least one filler selected from the group consisting of alumina and zircon. When using this glass composition as an insulating layer of a thick-film multilayer circuit board, there can be obtained a highly reliable thick-film multilayer circuit board in which the warpage of the substrate and leakage current are greatly reduced and the withstand voltage is highly improved.Type: GrantFiled: January 10, 1997Date of Patent: June 9, 1998Assignee: Shoei Chemical Inc.Inventors: Eiichi Asada, Tetsuya Tanaka
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Patent number: 5645765Abstract: A nontoxic lead-free conductive paste comprising (a) a lead-free glass frit having a crystallization temperature of 700.degree.-870.degree. C. and consisting essentially of, by weight %, 20-38% of SiO.sub.2, 5.5-13.5% of B.sub.2 O.sub.3, 8-15.5% of Al.sub.2 O.sub.3, 4-19% of CaO, 20-29% of ZnO, 0-6% of ZrO.sub.2, 4-16% of TiO.sub.2 and 0.1-3.8% of MoO.sub.3 ; (b) finely divided particles of electrically conductive material; (c) at least one inorganic additive selected from the group consisting of bismuth oxide, zinc oxide-containing containing oxide material, manganese oxide, copper oxide and molybdenum oxide; and (d) an organic medium. The nontoxic conductive paste is free from environmental and health problems and results in conductors having excellent solderability, solder leach resistance, adhesion strength and electrical properties, both on ceramic substrates such as alumina or on dielectric bodies.Type: GrantFiled: May 22, 1996Date of Patent: July 8, 1997Assignee: Shoei Chemical Inc.Inventors: Eiichi Asada, Tetsuya Tanaka
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Patent number: 5420744Abstract: A multilayered ceramic capacitor having internal electrodes comprising a substantially single-crystal metallic powder as a conductor, the powder having been produced by spraying a solution containing at least one metal salt to form droplets and heating the droplets to a temperature higher than the decomposition temperature of the metal salt and the melting point of the metal. When the metal salt forms an oxide at a temperature not higher than the melting point of the metal, the droplets are heated to a temperature higher than the decomposition temperature of the oxide. The multilayered capacitor is free from generated cracks in the ceramic material.Type: GrantFiled: September 21, 1993Date of Patent: May 30, 1995Assignee: Shoei Chemical Inc.Inventors: Eiichi Asada, Kazurou Nagashima
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Patent number: 5402305Abstract: An oxidation-resistant palladium powder containing one or more alkaline earth metal elements in a total amount of at least 0.005% by weight relative to Pd. The palladium powder is useful as a conductive component of a thick-film conductive paste and the resultant conductive paste can provide internal electrodes to a multilayered ceramic capacitor with minimized structural defects such as cracks or delamination. The palladium powder is produced by spraying a palladium salt solution containing one or more alkaline earth metal elements to form droplets and heating the droplets to a temperature of at least 1000.degree. C. The preferred amount of the alkaline earth metal elements in the Pd powder is from 0.005 to 0.1% by weight relative to Pd and the preferred alkaline earth metal elements are one or more elements selected from the group consisting of Mg, Ca, Sr and Ba.Type: GrantFiled: November 29, 1993Date of Patent: March 28, 1995Assignee: Shoei Chemical Inc.Inventors: Eiichi Asada, Yuji Akimoto, Shinichi Ono, Kazurou Nagashima, Mineto Iwasaki, Masayuki Maekawa
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Patent number: 4986933Abstract: A resistor composition comprising at least one electrically conductive powder selected from the group consisting of (a) tin oxide power and (b) powder resulting from heat treatment of tin oxide and tantalum oxide, a glass frit and double oxide of tantalum dispersed in an organic vehicle. In the resistor composition, the mixing amount of the double oxide of tantalum is preferably 30 parts by weight or less with respect to 100 parts by weight of the sum of the electrically conductive powder and the glass frit. The resistor composition provides highly reproducible thick film resistors having superior properties and high stability over a wide range of resistance by addition of the tantalum double oxides.Type: GrantFiled: March 21, 1990Date of Patent: January 22, 1991Assignee: Shoei Chemical Inc.Inventors: Eiichi Asada, Mikio Yamazoe, Shigeru Matsumura
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Patent number: 4752442Abstract: A bonding wire for use in semiconductor devices which consists essentially of 0.0003 to 0.01 wt. % of barium and the balance gold, the gold purity of said bonding wire being at least 99.99%. The bonding wire may further contain at least one element selected from the group consisting of 0.0005 to 0.005 wt. % of aluminum, 0.0001 to 0.003 wt. % of calcium, 0.0005 to 0.005 wt. % of silver and 0.0005 to 0.005 wt. % of palladium. The total content of the elements and barium in the bonding wire should not exceed 0.01 wt. % based on the weight of the bonding wire so that the gold purity of the bonding wire is at least 99.99%. The use of the additive elements improve the mechanical strength and wire-bondability, making the bonding wire highly suitable for use in wire bonding of semiconductor elements, especially for high-speed bonding.Type: GrantFiled: July 16, 1987Date of Patent: June 21, 1988Assignee: Shoei Chemical Inc.Inventors: Eiichi Asada, Kazuo Yokoyama, Masahiro Yata, Kenichi Hirano
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Patent number: 4574055Abstract: A resistor composition comprising conductive particles, a glass frit and a vehicle in which RuO.sub.2 particles coated with a polynary oxide of Bi and/or Pb and Ru are employed and, by using the surface-coated RuO.sub.2, the composition can provide readily a improved resistor having a advantageous combination of properties, particularly a very small absolute TCR and high voltage stability throughout a wide resistance range. The produced resistor can be successfully laser-trimmed without adversely affecting the properties thereof.Type: GrantFiled: December 12, 1984Date of Patent: March 4, 1986Assignee: Shoei Chemical Inc.Inventors: Eiichi Asada, Toshio Inokuma, Mikio Yamazoe