Patents by Inventor Nobuko Nakagawa
Nobuko Nakagawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20230366101Abstract: A grain-oriented electrical steel sheet with extremely excellent magnetic properties by removing an etching resist coating well to form narrow grooves on a metal strip surface even with low-output laser, while reducing thermal effects on the metal strip caused by laser irradiation, and a method for forming grooves on a metal strip surface, having forming an etching resist coating with 0 to 70 lightness L* on at least one side of the metal strip, irradiating laser with less than 1.5 kW output on the etching resist coating while scanning the laser in a direction that intersects a rolling direction of the metal strip to remove a portion of the etching resist coating irradiated by the laser, and etching a portion of the metal strip below the removed portion of the etching resist coating to form grooves, the lightness L* being a L* value in a CIELAB color space (CIE1976L*a*b* color space).Type: ApplicationFiled: July 2, 2021Publication date: November 16, 2023Applicant: JFE STEEL CORPORATIONInventors: Shigehiro TAKAJO, Takeshi OMURA, Nobuko NAKAGAWA
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Publication number: 20230002908Abstract: Disclosed is an electrical steel sheet with an insulating coating formed by applying a surface-treatment agent to at least one surface of the electrical steel sheet and drying the surface-treatment agent, wherein the surface-treatment agent contains: certain trialkoxysilane and/or dialkoxysilane (A); a silane coupling agent (B) that does not contain a polymerizable unsaturated group in its structure; plate-like silica (C); a polymerizable unsaturated-group-containing compound (D); and water, within a range satisfying the following conditions (1) to (3): (1) a mass ratio (A/B) of (A) to (B) is from 0.05 to 1.00; (2) a content of (C) is 2 mass % to 30 mass % with respect to a total mass of (A) to (D) in the surface-treatment agent; and (3) a content of (D) is 2 mass % to 18 mass % with respect to the total mass of (A) to (D) in the surface-treatment agent.Type: ApplicationFiled: October 13, 2020Publication date: January 5, 2023Applicant: JFE STEEL CORPORATIONInventors: Nobuko NAKAGAWA, Chiyoko TADA, Naoki MURAMATSU
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Publication number: 20220372600Abstract: A non-oriented electrical steel sheet produced by hot-rolling a steel slab containing Si: 2.8 to 6.5 mass % and Zn: 0.0005 to 0.0050 mass % followed by cold rolling and finish annealing, a coating agent containing at least one element from Sn, Sb, P, S, Se, As, Te, B, Pb, and Bi is applied to the surface after annealing forming an insulation coating with nitriding-suppressing ability. Alternatively, an intermediate layer containing at least one element from Sn, Sb, P, S, Se, As, Te, B, Pb, and Bi and having a nitriding-suppressing ability forms on the steel sheet iron matrix after the annealing and forms an insulation coating, without above elements, on the intermediate layer thus obtaining a non-oriented electrical steel sheet wherein a high strength rotor core with and stator core with excellent magnetic is simultaneously obtained, and a motor core including a stator core and rotor core from the steel sheet.Type: ApplicationFiled: October 12, 2020Publication date: November 24, 2022Applicant: JFE STEEL CORPORATIONInventors: Yoshiaki ZAIZEN, Nobuko NAKAGAWA, Yoshihiko ODA, Tomoyuki OKUBO, Chiyoko TADA
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Publication number: 20220194055Abstract: An electromagnetic steel sheet coated with an insulating film with excellent hardness and suitable for use as a material for iron cores of large-sized electric-power generators; and a process for producing the electromagnetic steel sheet coated with an insulating film. The purpose is achieved with a coating material for forming insulating films, the coating material including a solvent and components (A) to (C) contained therein in the respective amounts on a solid basis. (A) A water-compatible carboxylated resin; 100 parts by mass. (B) An aluminum-containing oxide; more than 40 parts by mass but less than 300 parts by mass per 100 parts by mass of the component (A). (C) At least one crosslinking agent selected from the group containing of melamine, isocyanates, and oxazoline; 100 parts by mass or more but less than 300 parts by mass per 100 parts by mass of the component (A).Type: ApplicationFiled: March 15, 2022Publication date: June 23, 2022Applicant: JFE STEEL CORPORATIONInventors: Nobuko NAKAGAWA, Naoki MURAMATSU, Chiyoko TADA, Kengo NAKAMURA, Tomonori SUGISHITA
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Publication number: 20220106689Abstract: An electrical steel sheet having excellent coating peel resistance that can be exhibited during a stamping process, so that sticking of the coating to a die is inhibited. The electrical steel sheet has an insulating coating disposed on at least one surface of the electrical steel sheet. The insulating coating (i) includes a composite comprising P and Al, (ii) has an aspect ratio in a range of 1 to 10, and (iii) has a thickness in a range of 500 nm to 2000 nm. The composite has a particle diameter in a range of 10 nm to 1000 nm.Type: ApplicationFiled: September 26, 2019Publication date: April 7, 2022Applicant: JFE STEEL CORPORATIONInventors: Naoki MURAMATSU, Nobuko NAKAGAWA, Chiyoko TADA
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Publication number: 20220028576Abstract: An electrical steel sheet provided with an insulating coating wherein the insulating coating is formed by a method includes forming an insulating coating on an electrical steel sheet, including: preparing a treatment solution that does not contain an Fe compound by adding an Si compound to water; applying the treatment solution to a surface of the electrical steel sheet; leaving the treatment solution on the surface of the electrical steel sheet to allow Fe in the electrical steel sheet to be dissolved in the treatment solution; and baking the treatment solution to form the insulating film such that a coating weight of Si in the insulating coating in terms of SiO2 is 50% to 99% of the total coating weight, and a ratio (Fe/Si) of content of Fe to content of Si in the insulating coating is 0.01 to 0.6 on a molar basis.Type: ApplicationFiled: October 5, 2021Publication date: January 27, 2022Inventors: Kazumichi Sashi, Nobuko Nakagawa, Naoki Muramatsu, Chiyoko Tada, Nobue Fujibayashi
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Patent number: 11186076Abstract: Provided is a method of manufacturing an electrical steel sheet with an adhesive insulating coating that has excellent high-temperature adhesive property and high-temperature oil resistance and, even after being stacked and subjected to stress relief annealing, has excellent magnetic properties (iron loss, magnetic flux density). The method comprises: applying a coating material to at least one side of an electrical steel sheet, the coating material containing (a) an aqueous epoxy resin, (b) a high-temperature hardening crosslinking agent in an amount of 30 parts by mass or less with respect to 100 parts by mass of the aqueous epoxy resin, in terms of solid content, (c) metal oxide particles, and (d) a solvent; and baking the coating material applied to the electrical steel sheet, under a condition of a peak steel sheet temperature of 150° C. or more and less than 230° C.Type: GrantFiled: December 11, 2017Date of Patent: November 30, 2021Assignee: JFE STEEL CORPORATIONInventors: Nobuko Nakagawa, Naoki Muramatsu, Chiyoko Tada
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Patent number: 11177052Abstract: A method for forming an insulating coating on an electrical steel sheet is provided. The method includes preparing a treatment solution by adding a Si compound to water and applying the treatment solution to a surface of the electrical steel sheet. Fe in the electrical steel sheet dissolves in the treatment solution and, thereafter, the electrical steel sheet and treatment solution are baked to form the insulating film. In the insulating film, a coating weight of Si in terms of SiO2 is 50% to 99% of the total coating weight, and a ratio (Fe/Si) of content of Fe to content of Si in the insulating coating is 0.01 to 0.6 on a molar basis.Type: GrantFiled: July 22, 2019Date of Patent: November 16, 2021Assignee: JFE Steel CorporationInventors: Kazumichi Sashi, Nobuko Nakagawa, Naoki Muramatsu, Chiyoko Tada, Nobue Fujibayashi
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Publication number: 20210324491Abstract: An electrical steel sheet with an insulating film having excellent chromium elution resistance, even in the case where the insulating film is baked by utilizing rapid heating, which improves productivity, and a method for manufacturing the steel sheet. The insulating film contains Fe, Cr, an organic resin, and an organic reducing agent on at least one surface of an electrical steel sheet. A ratio of the Fe content to the Cr content (Fe/Cr) is 0.010 to 0.6 in terms of molar ratio in the insulating film.Type: ApplicationFiled: July 8, 2019Publication date: October 21, 2021Applicant: JFE STEEL CORPORATIONInventors: Chiyoko TADA, Nobuko NAKAGAWA, Takashi WADA, Shota TSUJI, Naoki MURAMATSU
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Publication number: 20200086619Abstract: Provided is a method of manufacturing an electrical steel sheet with an adhesive insulating coating that has excellent high-temperature adhesive property and high-temperature oil resistance and, even after being stacked and subjected to stress relief annealing, has excellent magnetic properties (iron loss, magnetic flux density). The method comprises: applying a coating material to at least one side of an electrical steel sheet, the coating material containing (a) an aqueous epoxy resin, (b) a high-temperature hardening crosslinking agent in an amount of 30 parts by mass or less with respect to 100 parts by mass of the aqueous epoxy resin, in terms of solid content, (c) metal oxide particles, and (d) a solvent; and baking the coating material applied to the electrical steel sheet, under a condition of a peak steel sheet temperature of 150° C. or more and less than 230° C.Type: ApplicationFiled: December 11, 2017Publication date: March 19, 2020Applicant: JFE STEEL CORPORATIONInventors: Nobuko NAKAGAWA, Naoki MURAMATSU, Chiyoko TADA
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Patent number: 10526672Abstract: The disclosure provides an electrical steel sheet with an insulating coating excellent in both punchability and powdering resistance, without any chromium compound being contained in the insulating coating. The electrical steel sheet with an insulating coating includes an electrical steel sheet and an insulating coating formed on the electrical steel sheet. The insulating coating contains Si and particulate organic resin. The organic resin contains primary particles having an average primary particle size of 1.0 ?m or less, and 5% or more and 50% or less of the primary particles of the organic resin are agglomerated particles.Type: GrantFiled: April 5, 2016Date of Patent: January 7, 2020Assignee: JFE STEEL CORPORATIONInventors: Naoki Muramatsu, Nobuko Nakagawa, Kazumichi Sashi, Chiyoko Tada
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Publication number: 20190348195Abstract: A method for forming an insulating coating on an electrical steel sheet is provided. The method includes preparing a treatment solution by adding a Si compound to water and applying the treatment solution to a surface of the electrical steel sheet. Fe in the electrical steel sheet dissolves in the treatment solution and, thereafter, the electrical steel sheet and treatment solution are baked to form the insulating film. In the insulating film, a coating weight of Si in terms of SiO2 is 50% to 99% of the total coating weight, and a ratio (Fe/Si) of content of Fe to content of Si in the insulating coating is 0.01 to 0.6 on a molar basis.Type: ApplicationFiled: July 22, 2019Publication date: November 14, 2019Inventors: Kazumichi Sashi, Nobuko Nakagawa, Naoki Muramatsu, Chiyoko Tada, Nobue Fujibayashi
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Patent number: 10403417Abstract: An electrical steel sheet is provided with insulating coating. The insulating coating contains Si and Fe. The coating weight of Si in the insulating coating in terms of SiO2 is 50% to 99% of the total coating weight. The ratio (Fe/Si) of the content of Fe to the content of Si in the insulating coating is 0.01 to 0.6 on a molar basis. The ratio (C (the organic resin+the lubricant)/(Fe2O3+SiO2)) of the coating weight of the organic resin and/or the lubricant in terms of C to the sum of the coating weight of Fe in terms of Fe2O3 and the coating weight of Si in terms of SiO2 preferably is 0.05 to 0.8.Type: GrantFiled: November 11, 2014Date of Patent: September 3, 2019Assignee: JFE Steel CorporationInventors: Kazumichi Sashi, Nobuko Nakagawa, Naoki Muramatsu, Chiyoko Tada, Nobue Fujibayashi
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Publication number: 20190160786Abstract: An electromagnetic steel sheet coated with an insulating film with excellent hardness and suitable for use as a material for iron cores of large-sized electric-power generators; and a process for producing the electromagnetic steel sheet coated with an insulating film. The purpose is achieved with a coating material for forming insulating films, the coating material including a solvent and components (A) to (C) contained therein in the respective amounts on a solid basis. (A) A water-compatible carboxylated resin; 100 parts by mass. (B) An aluminum-containing oxide; more than 40 parts by mass but less than 300 parts by mass per 100 parts by mass of the component (A). (C) At least one crosslinking agent selected from the group containing of melamine, isocyanates, and oxazoline; 100 parts by mass or more but less than 300 parts by mass per 100 parts by mass of the component (A).Type: ApplicationFiled: August 1, 2017Publication date: May 30, 2019Applicant: JFE STEEL CORPORATIONInventors: Nobuko NAKAGAWA, Naoki MURAMATSU, Chiyoko TADA, Kengo NAKAMURA, Tomonori SUGISHITA
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Publication number: 20180251869Abstract: The disclosure provides an electrical steel sheet with an insulating coating excellent in both punchability and powdering resistance, without any chromium compound being contained in the insulating coating. The electrical steel sheet with an insulating coating includes an electrical steel sheet and an insulating coating formed on the electrical steel sheet. The insulating coating contains Si and particulate organic resin. The organic resin contains primary particles having an average primary particle size of 1.0 ?m or less, and 5% or more and 50% or less of the primary particles of the organic resin are agglomerated particles.Type: ApplicationFiled: April 5, 2016Publication date: September 6, 2018Applicant: JFE STEEL CORPORATIONInventors: Naoki MURAMATSU, Nobuko NAKAGAWA, Kazumichi SASHI, Chiyoko TADA
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Publication number: 20170162295Abstract: An electrical steel sheet is provided with insulating coating. The insulating coating contains Si and Fe. The coating weight of Si in the insulating coating in terms of SiO2 is 50% to 99% of the total coating weight. The ratio (Fe/Si) of the content of Fe to the content of Si in the insulating coating is 0.01 to 0.6 on a molar basis. The ratio (C (the organic resin+the lubricant)/(Fe2O3+SiO2)) of the coating weight of the organic resin and/or the lubricant in terms of C to the sum of the coating weight of Fe in terms of Fe2O3 and the coating weight of Si in terms of SiO2 preferably is 0.05 to 0.8.Type: ApplicationFiled: November 11, 2014Publication date: June 8, 2017Inventors: Kazumichi Sashi, Nobuko Nakagawa, Naoki Muramatsu, Chiyoko Tada, Nobue Fujibayashi
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Publication number: 20170117758Abstract: A stacked electrical steel sheet used for a stacked iron core of an automotive motor and the like required to have high-temperature bond property and high-temperature oil resistance is provided. An electrical steel sheet for stacking includes: an electrical steel sheet; and a bond-type insulating coating formed on at least one surface of the electrical steel sheet and having Martens hardness HM of 50 or more and less than 500.Type: ApplicationFiled: July 24, 2015Publication date: April 27, 2017Applicant: JFE STEEL CORPORATIONInventors: Nobuko NAKAGAWA, Kazumichi SASHI, Naoki MURAMATSU, Chiyoko TADA
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Patent number: 9534136Abstract: A semi-organic insulation coating includes an inorganic component and an organic resin, a Zr compound and an Si compound contains a plate-like silica as an inorganic component and are included in a ratio in a dry coating of 20 to 70 mass % of Zr compound (converted to ZrO2) and 10 to 50 mass % of Si compound containing plate-like silica (converted to SiO2), and the remainder is substantially an organic resin, whereby a magnetic steel sheet with a semi-organic insulation coating has no deterioration of corrosion resistance and water resistance without containing a chromium compound and being excellent in powdering resistance, scratch resistance, sticking resistance, TIG weldability, punchability and coating appearance.Type: GrantFiled: July 21, 2011Date of Patent: January 3, 2017Assignee: JFE Steel CorporationInventors: Kazumichi Sashi, Hiroyuki Ogata, Chiyoko Tada, Nobuko Nakagawa, Nobue Fujibayashi, Tomofumi Shigekuni, Kenichi Sasaki
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Publication number: 20160230024Abstract: A coating material that forms an insulation coating, containing apart from a solvent: an aqueous carboxy group-containing resin as component (A) in an amount of 100 parts by mass in terms of solid content; an aluminum-containing oxide as component (B) in an amount of not less than 100 parts by mass but less than 300 parts by mass in terms of solid content, based on the component (A) present in an amount of 100 parts by mass in terms of solid content; and at least one crosslinking agent as component (C) selected from the group consisting of melamine, isocyanate and oxazoline, in an amount of more than 20 parts by mass but less than 100 parts by mass in terms of solid content, based on the component (A) present in an amount of 100 parts by mass in terms of solid content.Type: ApplicationFiled: August 18, 2014Publication date: August 11, 2016Inventors: Nobuko Nakagawa, Chiyoko Tada, Kengo Nakamura, Hiroaki Kimura
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Publication number: 20150044475Abstract: The present invention includes an electrical steel sheet with an insulation coating having a large interlaminar insulation resistance when laminated; a coating material for forming the insulation coating that is used for the electrical steel sheet and the coating material for forming the insulation coating, which includes apart from a solvent an aqueous carboxy group-containing resin as component (A), an aluminum-containing oxide as component (B), and at least one crosslinking agent as component (C) selected from the group consisting of melamine, isocyanate and oxazoline. There are component (A); 100 parts by mass; 40 parts by mass<component (B)<150 parts by mass; 20 parts by mass<component (C)<100 parts by mass.Type: ApplicationFiled: February 25, 2013Publication date: February 12, 2015Applicants: JFE STEEL CORPORATION, DAI NIPPON TORYO CO., LTD.Inventors: Nobuko Nakagawa, Tomofumi Shigekuni, Takahiro Kubota, Osamu Tanida