# US 12,009,137 B2 · Magnetic particles, dust core, and coil component > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,009,137 B2 - Document ID: US12009137B2 - Status: Granted - Kind: B2 - Application number: 17/938,004 - Filed: 2022-10-04 - Published: 2023-02-09 - Granted: 2024-06-11 - Earliest claimed: 2017-01-12 - Assignees: Murata Manufacturing Co., Ltd. - Applicants: Murata Manufacturing Co., Ltd. - Inventors: Hironobu Kubota; Yuya Ishida - Web page: https://patentgrep.com/patent/US12009137B2 ## CPC - H01F 27/255: made from particles (H01F27/26 takes precedence) - B22F 1/102: Metallic powder coated with organic material - B22F 5/106: {Tube or ring forms} - H01F 1/147: Alloys characterised by their composition {(treatment thereof for enhancing their electromagnetic properties C21D8/12)} - H01F 1/26: by macromolecular organic substances - H01F 3/08: made from powder (powder coatings on sheets H01F3/02; on strips or ribbons H01F3/04; on wires H01F3/06) - H01F 27/28: Coils; Windings; Conductive connections - H01F 41/0246: {Manufacturing of magnetic circuits by moulding or by pressing powder (magnetic cores made by moulding or by pressing powder H01F27/255; soft magnetic particles H01F1/20, H01F1/36)} - B22F 1/10: Metallic powder containing lubricating or binding agents; Metallic powder containing organic material - B22F 2301/35: Iron - C22C 33/02: by powder metallurgy - C22C 2202/02: Magnetic - H01F 1/24: the particles being insulated - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES - 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) ## Abstract Magnetic particles, each including a core made of a magnetic material, and an insulating coating film which covers a surface of the core made of a magnetic material. The insulating coating film is formed of a sol-gel reaction product of a mixture containing a metal alkoxide and an organic phosphoric acid or a salt thereof. ## Claims ### Claim 1 Magnetic particles, each comprising a core made of a magnetic material, and a first insulating coating film and a second insulating coating film which cover the core made of a magnetic material, wherein the first insulating coating film and the second insulating coating film are formed of a sol-gel reaction product, and one or both of the first insulating coating film and the second insulating coating film includes a surfactant that is at least one selected from the group consisting of sodium polyoxyalkylene styryl phenyl ether phosphate, sodium polyoxyalkylene alkyl ether phosphate, polyoxyalkylene alkyl aryl ether phosphoric acid monoethanolamine salt, sodium alkyl ether phosphate, unsaturated polyoxyethylene alkyl phenyl ether ammonium phosphate, sodium polyoxyethylene tridecyl ether sulfate, sodium dodecylbenzenesulfonate, polyoxyethylene alkyl ether styrenated phenyl ether ammonium sulfate, polyoxyethylene tridecyl ether, polyoxyethylene sorbitan monostearate, lauryl trimethyl ammonium chloride, and lauryl dimethyl ethyl ammonium ethyl sulfate, wherein a content of the surfactant is 0.05 parts by weight or more relative to 100 parts by weight of the magnetic material. ### Claim 2 (depends on 1) The magnetic particles according to claim 1, wherein one or both of the first insulating coating film and the second insulating coating film are formed of a sol-gel reaction product of a mixture of a metal alkoxide and the surfactant. ### Claim 3 (depends on 2) The magnetic particles according to claim 2, wherein the first insulating coating film is formed of a sol-gel reaction product of a mixture of a metal alkoxide, the surfactant, and a silane coupling agent. ### Claim 4 (depends on 3) The magnetic particles according to claim 3, wherein the second insulating coating film is formed of a material different from that of the first insulating coating film. ### Claim 5 (depends on 2) The magnetic particles according to claim 2, wherein the second insulating coating film is formed of a material different from that of the first insulating coating film. ### Claim 6 (depends on 2) The magnetic particles according to claim 2, wherein the weight ratio of the metal alkoxide to the surfactant is from 0.06 to 40.0. ### Claim 7 (depends on 1) The magnetic particles according to claim 1, wherein the first insulating coating film is formed of a sol-gel reaction product of a mixture of a metal alkoxide, the surfactant, and a silane coupling agent. ### Claim 8 (depends on 7) The magnetic particles according to claim 7, wherein the second insulating coating film is formed of a material different from that of the first insulating coating film. ### Claim 9 (depends on 1) The magnetic particles according to claim 1, wherein the second insulating coating film is formed of a material different from that of the first insulating coating film. ### Claim 10 (depends on 1) The magnetic particles according to claim 1, wherein the magnetic particles have a relative permeability of 28 or greater and a specific resistance of 7.8×10{circumflex over ( )}6 Ω·cm or greater. ### Claim 11 (depends on 1) The magnetic particles according to claim 1, wherein the magnetic particles have a relative permeability of 34 or greater and a specific resistance of 1.1×10{circumflex over ( )}9 Ω·cm or greater. ### Claim 12 Magnetic particles, each comprising a core made of a magnetic material, and an insulating coating film which covers the core made of a magnetic material, wherein the insulating coating film is formed of a reaction product of a metal alkoxide and a surfactant, the surfactant being at least one selected from the group consisting of sodium polyoxyalkylene styryl phenyl ether phosphate, sodium polyoxyalkylene alkyl ether phosphate, polyoxyalkylene alkyl aryl ether phosphoric acid monoethanolamine salt, sodium alkyl ether phosphate, unsaturated polyoxyethylene alkyl phenyl ether ammonium phosphate, sodium polyoxyethylene tridecyl ether sulfate, sodium dodecylbenzenesulfonate, polyoxyethylene alkyl ether styrenated phenyl ether ammonium sulfate, polyoxyethylene tridecyl ether, polyoxyethylene sorbitan monostearate, lauryl trimethyl ammonium chloride, and lauryl dimethyl ethyl ammonium ethyl sulfate, wherein a content of the surfactant is 0.05 parts by weight or more relative to 100 parts by weight of the magnetic material. ### Claim 13 (depends on 12) The magnetic particles according to claim 12, wherein the insulating coating film is formed of a reaction product of a metal alkoxide, the surfactant, and a silane coupling agent.