# US 2022/0274162 A1 · Nickel powder, method for manufacturing nickel powder, internal electrode paste using nickel powder, and electronic component > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0274162 A1 - Document ID: US20220274162A1 - Status: Published application - Kind: A1 - Application number: 17/744,086 - Filed: 2022-05-13 - Published: 2022-09-01 - Earliest claimed: 2016-03-18 - Assignees: Sumitomo Metal Mining Co., Ltd.; Murata Manufacturing Co., Ltd. - Applicants: Sumitomo Metal Mining Co., Ltd.; Murata Manufacturing Co., Ltd. - Inventors: Junji ISHII; Shingo MURAKAMI; Hiroyuki TANAKA; Takahiro KAMATA; Toshiaki TERAO; Masaya YUKINOBU; Yuji WATANABE; Tsutomu TANIMITSU; Yoshiyuki KUNIFUSA; Haruo NISHIYAMA - Web page: https://patentgrep.com/patent/US20220274162A1 ## CPC - B22F 9/24: starting from liquid metal compounds, e.g. solutions - B22F 1/065: Spherical particles - B22F 1/16: Metallic particles coated with a non-metal (coated with lubricating or binding agents or with organic material B22F1/10) - C22C 19/03: based on nickel - H01B 1/02: mainly consisting of metals or alloys - H01B 1/22: the conductive material comprising metals or alloys - B22F 2301/15: Nickel or cobalt - B22F 2304/054: Particle size between 1 and 100 nm - B22F 2304/056: Particle size above 100 nm up to 300 nm - B22F 2304/058: Particle size above 300 nm up to 1 micrometer - B22F 2999/00: Aspects linked to processes or compositions used in powder metallurgy - B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER - C22C: ALLOYS (treatment of alloys C21D, C22F) - H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K}) ## Abstract To provide a fine nickel powder for an internal electrode paste of an electronic component, the nickel powder obtained by a wet method and having high crystallinity, excellent sintering characteristics, and heat-shrinking characteristics. The nickel powder is obtained by precipitating nickel by a reduction reaction in a reaction solution including at least water-soluble nickel salt, salt of metal nobler than nickel, hydrazine as a reducing agent, and alkali metal hydroxide as a pH adjusting agent and water; the reaction solution is prepared by mixing a nickel salt solution including the water-soluble nickel salt and the salt of metal nobler than nickel with a mixed reducing agent solution including hydrazine and alkali metal hydroxide; and the hydrazine is additionally added to the reaction solution after a reduction reaction initiates in the reaction solution. ## Claims ### Claim 1 A manufacturing method of nickel powder comprising a crystallization process to obtain nickel crystallization powder by precipitating nickel by a reduction reaction in a reaction solution including at least water-soluble nickel salt, metal salt of metal that is nobler than nickel, hydrazine as a reducing agent, alkali metal hydroxide as a pH adjusting agent, and water; the reaction solution prepared by mixing a nickel salt solution including the water-soluble nickel salt and the metal salt of metal that is nobler than nickel with a mixed reducing agent solution including the hydrazine and the alkali metal hydroxide; the hydrazine additionally added to the reaction solution after a reduction reaction initiates in the reaction solution; and an amount of initial hydrazine that is hydrazine among the hydrazine being formulated in the mixed reducing agent solution set in a range of 0.05 to 1.0 at a molar ratio to nickel, and an amount of additional hydrazine among the hydrazine being additionally added to the reaction solution set in a range of 1.0 to 3.2 at a molar ratio to nickel. ### Claim 2 A manufacturing method of nickel powder comprising a crystallization process to obtain nickel crystallization powder by precipitating nickel by a reduction reaction in a reaction solution including at least water-soluble nickel salt, metal salt of metal that is nobler than nickel, hydrazine as a reducing agent, alkali metal hydroxide as a pH adjusting agent, and water; the reaction solution prepared by mixing a nickel salt solution including the water-soluble nickel salt and the metal salt of metal that is nobler than nickel with a reducing agent solution including the hydrazine but not including the alkali metal hydroxide, and then adding an alkali metal hydroxide solution including the alkali metal hydroxide thereto; the hydrazine additionally added to the reaction solution after a reduction reaction initiates in the reaction solution; and an amount of initial hydrazine that is hydrazine among the hydrazine being formulated in the reducing agent solution set in a range of 0.05 to 1.0 at a molar ratio to nickel; further, the amount of additional hydrazine among the hydrazine being additionally added to the reaction solution set in a range of 1.0 to 3.2 at a molar ratio to nickel. ### Claim 3 (depends on 1) The manufacturing method of nickel powder according to claim 1, wherein the additional hydrazine is additionally added to the reaction solution over multiple times. ### Claim 4 (depends on 1) The manufacturing method of nickel powder according to claim 1, wherein the additional hydrazine is additionally added by dripping continuously. ### Claim 5 (depends on 4) The manufacturing method of nickel powder according to claim 4, wherein the dripping speed is in a range of 0.8/h to 9.6/h at a molar ratio to nickel. ### Claim 6 (depends on 1) The manufacturing method of nickel powder according to claim 1, wherein, as the metal salt of metal that is nobler than nickel, at least any one of a copper salt, and one or more noble metal salts selected from gold salt, silver salt, platinum salt, palladium salt, rhodium salt, and iridium salt is used. ### Claim 7 (depends on 6) The manufacturing method of nickel powder according to claim 6, wherein the copper salt and the noble metal salt are concurrently used, and a molar ratio of the noble metal salt to the copper salt is within a range of 0.01 to 5.0. ### Claim 8 (depends on 1) The manufacturing method of nickel powder according to claim 1, wherein, purified hydrazine where organic impurities included in hydrazine have been removed is used as the hydrazine. ### Claim 9 (depends on 1) The manufacturing method of nickel powder according to claim 1, wherein any one of sodium hydroxide, potassium hydroxide, and a mixture of these is used as the alkali metal hydroxide. ### Claim 10 (depends on 1) The manufacturing method of nickel powder according to claim 1, wherein a complexing agent is included to at least either of the nickel salt solution and the reducing agent solution. ### Claim 11 (depends on 10) The manufacturing method of nickel powder according to claim 10, wherein, as the complexing agent, one or more selected from hydroxy carboxylic acid, hydroxy carboxylic acid salt, hydroxy carboxylic acid derivatives, carboxylic acid, carboxylic acid salt, and carboxylic acid derivatives is used, and an amount of the complexing agent is within a range of 0.05 to 1.2 in a molar ratio to nickel. ### Claim 12 (depends on 1) The manufacturing method of nickel powder according to claim 1, wherein a reaction initiation temperature that is a temperature of the reaction solution at an initiation of the crystallization reaction is in a range of 60° C. to 95° C. ### Claim 13 (depends on 1) The manufacturing method of nickel powder according to claim 1, wherein a sulfur coating agent is added to nickel powder slurry that is an aqueous solution including the nickel powder obtained in the crystallization to obtain nickel powder having a surface modified with sulfur. ### Claim 14 (depends on 13) The manufacturing method of nickel powder according to claim 13, wherein, water-soluble sulfur compounds including at least either of mercapto group and disulfide group is used. ### Claim 15 (depends on 2) The manufacturing method of nickel powder according to claim 2, wherein the additional hydrazine is additionally added to the reaction solution over multiple times. ### Claim 16 (depends on 2) The manufacturing method of nickel powder according to claim 2, wherein the additional hydrazine is additionally added by dripping continuously. ### Claim 17 (depends on 2) The manufacturing method of nickel powder according to claim 2, wherein, as the metal salt of metal that is nobler than nickel, at least any one of a copper salt, and one or more noble metal salts selected from gold salt, silver salt, platinum salt, palladium salt, rhodium salt, and iridium salt is used. ### Claim 18 (depends on 2) The manufacturing method of nickel powder according to claim 2, wherein, purified hydrazine where organic impurities included in hydrazine have been removed is used as the hydrazine. ### Claim 19 (depends on 2) The manufacturing method of nickel powder according to claim 2, wherein any one of sodium hydroxide, potassium hydroxide, and a mixture of these is used as the alkali metal hydroxide. ### Claim 20 (depends on 2) The manufacturing method of nickel powder according to claim 2, wherein a complexing agent is included to at least either of the nickel salt solution and the reducing agent solution. ### Claim 21 (depends on 2) The manufacturing method of nickel powder according to claim 2, wherein a reaction initiation temperature that is a temperature of the reaction solution at an initiation of the crystallization reaction is in a range of 60° C. to 95° C. ### Claim 22 (depends on 2) The manufacturing method of nickel powder according to claim 2, wherein a sulfur coating agent is added to nickel powder slurry that is an aqueous solution including the nickel powder obtained in the crystallization to obtain nickel powder having a surface modified with sulfur. ### Claim 23 (depends on 2) The manufacturing method of nickel powder according to claim 2, wherein, water-soluble sulfur compounds including at least either of mercapto group and disulfide group is used.