# US 2015/0147584 A1 · Fibrous copper microparticles and method for manufacturing same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2015/0147584 A1 - Document ID: US20150147584A1 - Status: Published application - Kind: A1 - Application number: 14/405,166 - Filed: 2013-06-11 - Published: 2015-05-28 - Earliest claimed: 2012-06-11 - Assignees: Unitika Ltd. - Inventors: Munenori Yamada; Kou Takeuchi; Mutsumi Matsushita; Akira Shigeta; Masahiro Hosoda; Yoshiaki Echigo - Web page: https://patentgrep.com/patent/US20150147584A1 ## CPC - B22F 9/24: starting from liquid metal compounds, e.g. solutions - B22F 1/062: Fibrous particles - C22C 9/00: Alloys based on copper - H01B 1/026: {Alloys based on copper} - H01B 1/16: the conductive material comprising metals or alloys - Y10T 428/12: All metal or with adjacent metals - Y10T 428/256: Heavy metal or aluminum or compound thereof - 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}) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract Fibrous copper microparticles having a minor axis of 1 μm or less and an aspect ratio of 10 or more, wherein the content of the copper particles having a minor axis of 0.3 μm or more and an aspect ratio of 1.5 or less is 0.1 or less copper particle per one fibrous copper microparticle. ## Claims ### Claim 1 Fibrous copper microparticles having a minor axis of 1 μm or less and an aspect ratio of 10 or more, wherein a content of copper particles having a minor axis of 0.3 μm or more and an aspect ratio of 1.5 or less is 0.1 or less copper particle per one fibrous copper microparticle. ### Claim 2 (depends on 1) The fibrous copper microparticles according to claim 1, wherein a length of the fibrous copper microparticles is 1 μm or more. ### Claim 3 (depends on 1) A method for manufacturing the fibrous copper microparticles according to claim 1, comprising precipitating the fibrous copper microparticles from an aqueous solution containing copper ion, an alkaline compound, a nitrogen-containing compound to form a complex with copper ion, and a reducing compound, wherein a residual rate A of a dissolved oxygen concentration in the alkaline aqueous solution represented by the following formula [1] is 0.5 or more: Residual rate A of dissolved oxygen concentration=(Dissolved oxygen concentration (C10) after 10 minutes from addition of reducing compound)/(dissolved oxygen concentration (C0) before addition of reducing compound) [1] ### Claim 4 (depends on 3) The method for manufacturing fibrous copper microparticles according to claim 3, wherein the reducing compound is one or more compounds selected from ascorbic acid, erythorbic acid and glucose. ### Claim 5 (depends on 3) The method for manufacturing fibrous copper microparticles according to claim 3, wherein a residual rate B of the dissolved oxygen concentration in the alkaline aqueous solution represented by the following formula [2] is 0.9 or less: Residual rate B of dissolved oxygen concentration=(Dissolved oxygen concentration (C60) after 60 minutes from addition of reducing compound)/(dissolved oxygen concentration (C10) after 10 minutes from addition of reducing compound) [2] ### Claim 6 (depends on 5) The method for manufacturing fibrous copper microparticles according to claim 5, wherein the reducing compound is ascorbic acid and/or erythorbic acid. ### Claim 7 (depends on 1) An electrically conductive coating agent comprising the fibrous copper microparticles according to claim 1. ### Claim 8 (depends on 1) An electrically conductive layer comprising the fibrous copper microparticles according to claim 1. ### Claim 9 (depends on 8) An electrically conductive film comprising a substrate, and the electrically conductive layer according to claim 8, formed on the substrate. ### Claim 10 (depends on 2) A method for manufacturing the fibrous copper microparticles according to claim 2, comprising precipitating the fibrous copper microparticles from an aqueous solution containing copper ion, an alkaline compound, a nitrogen-containing compound to form a complex with copper ion, and a reducing compound, wherein a residual-rate A of a dissolved oxygen concentration in the alkaline aqueous solution represented by the following formula [1] is 0.5 or more: Residual rate A of dissolved oxygen concentration=(Dissolved oxygen concentration (C10) after 10 minutes from addition of reducing compound)/(dissolved oxygen concentration (C0) before addition of reducing compound) [1] ### Claim 11 (depends on 10) The method for manufacturing fibrous copper microparticles according to claim 10, wherein the reducing compound is one or more compounds selected from ascorbic acid, erythorbic acid and glucose. ### Claim 12 (depends on 10) The method for manufacturing fibrous copper microparticles according to claim 10, wherein a residual rate B of the dissolved oxygen concentration in the alkaline aqueous solution represented by the following formula [2] is 0.9 or less: Residual rate B of dissolved oxygen concentration=(Dissolved oxygen concentration (C60) after 60 minutes from addition of reducing compound)/(dissolved oxygen concentration (C10) after 10 minutes from addition of reducing compound) [2] ### Claim 13 (depends on 12) The method for manufacturing fibrous copper microparticles according to claim 12, wherein the reducing compound is ascorbic acid and/or erythorbic acid. ### Claim 14 (depends on 2) An electrically conductive coating agent comprising the fibrous copper microparticles according to claim 2. ### Claim 15 (depends on 2) An electrically conductive layer comprising the fibrous copper microparticles according to claim 2. ### Claim 16 (depends on 15) An electrically conductive film comprising a substrate, and the electrically conductive layer according to claim 15, formed on the substrate.