Patents Assigned to Dowa F-Tec Co., Ltd.
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Patent number: 10665371Abstract: A ferrite powder for bonded magnets having a high iHc value usable even in a low temperature environment, a method for producing the same, and a bonded magnet using the ferrite powder and having high iHc value which can be used even in a low temperature environment, wherein a specific surface area is 2.20 m2/g or more and less than 3.20 m2/g; a compression density is 3.30 g/cm3 or more and less than 3.60 g/cm3, and a compressed molding has a coercive force of 3250 Oe or more and less than 3800 Oe.Type: GrantFiled: September 30, 2015Date of Patent: May 26, 2020Assignees: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA F-TEC CO., LTD.Inventors: Satoru Tsuboi, Yasunobu Mishima, Keisuke Ayabe, Masayasu Senda
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Patent number: 10453596Abstract: There is provided a ferrite powder for bonded magnets capable of producing ferrite bonded magnets with high BHmax, excellent in MFR when converted to a compound, with high p-iHc, wherein an average particle size of particles obtained by a dry laser diffraction measurement is 5 ?m or less, a specific surface area is 1.90 m2/g or more and less than 3.00 m2/g, a compression density is 3.40 g/cm3 or more and less than 3.73 g/cm3, and a compressed molding has a coercive force of 2800 Oe or more and less than 3250 Oe.Type: GrantFiled: September 30, 2015Date of Patent: October 22, 2019Assignees: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA F-TEC CO., LTD.Inventors: Satoru Tsuboi, Yasunobu Mishima, Keisuke Ayabe, Masayasu Senda
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Publication number: 20180244537Abstract: A ferrite powder for bonded magnets capable of producing a ferrite bonded magnet having a BHmax value of 2.65 MGOe or more when molded in a magnetic field and a method for producing the same, and a ferrite bonded magnet using the same, wherein a compression density is 3.50 g/cm3 or more, and an average value of a (long axis length/short axis length) ratio of ferrite particles having a long axis length of 1.0 ?m or more is, 1.60 or less.Type: ApplicationFiled: February 23, 2016Publication date: August 30, 2018Applicants: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA F-TEC CO., LTD.Inventors: Tomoya YAMADA, Satoru TSUBOI, Keisuke AYABE, Yasunobu MISHIMA, Masayasu SENDA
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Publication number: 20170316857Abstract: There is provided a ferrite powder for bonded magnets capable of producing ferrite bonded magnets with high BHmax, excellent in MFR when converted to a compound, with high p-iHc, wherein an average particle size of particles obtained by a dry laser diffraction measurement is 5 ?m or less, a specific surface area is 1.90 m2/g or more and less than 3.00 m2/g, a compression density is 3.40 g/cm3 or more and less than 3.73 g/cm3, and a compressed molding has a coercive force of 2800 Oe or more and less than 3250 Oe.Type: ApplicationFiled: September 30, 2015Publication date: November 2, 2017Applicants: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA F-TEC CO., LTD.Inventors: Satoru TSUBOI, Yasunobu MISHIMA, Keisuke AYABE, Masayasu SENDA
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Publication number: 20170309381Abstract: A ferrite powder for bonded magnets capable of producing a ferrite bonded magnet having high BHmax, and excellent in fluidity when converted to a compound, and having a high p-iHc value, and a method for producing the same, and a ferrite bonded magnet using the ferrite powder for bonded magnets, wherein an average particle size of particles obtained by a dry laser diffraction measurement is 5 ?m or less; a specific surface area is 1.90 m2/g or more and less than 2.80 m2/g; a compression density is 3.50 g/cm3 or more and less than 3.78 g/cm3, and a compressed molding has a coercive force of 2300 Oe or more and less than 2800 Oe.Type: ApplicationFiled: September 30, 2015Publication date: October 26, 2017Applicants: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA F-TEC CO., LTD.Inventors: Satoru TSUBOI, Yasunobu MISHIMA, Keisuke AYABE, Masayasu SENDA
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Publication number: 20170301440Abstract: A ferrite powder for bonded magnets having a high iHc value usable even in a low temperature environment, a method for producing the same, and a bonded magnet using the ferrite powder and having high iHc value which can be used even in a low temperature environment, wherein a specific surface area is 2.20 m2/g or more and less than 3.20 m2/g; a compression density is 3.30 g/cm3 or more and less than 3.60 g/cm3, and a compressed molding has a coercive force of 3250 Oe or more and less than 3800 Oe.Type: ApplicationFiled: September 30, 2015Publication date: October 19, 2017Applicants: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA F-TEC CO., LTD.Inventors: Satoru TSUBOI, Yasunobu MISHIMA, Keisuke AYABE, Masayasu SENDA
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Patent number: 9708221Abstract: Provided are an inexpensive brick, etc., naturally exhibiting excellent radiation shielding effects, demonstrating high strength while being chemically stable and not including harmful substances, and also being suitable for use in facility in which devices affected by magnetic fields are installed. Manufactured are a brick, etc., for constructing a ?-shielding structure or constructing an X-ray shielding structure, in which a molding material including hematite in a ratio of at least 90% by mass is molded into a predetermined shape to obtain a molded article, and the molded article is fired, whereby the fired molded article is endowed with a bulk density of at least 2.8 g/cm3, and the fired molded article is endowed with a residual magnetization of 1.0 A·m2·g?1 or less.Type: GrantFiled: February 25, 2014Date of Patent: July 18, 2017Assignees: MITSUISHI TAIKA RENGA CO., LTD., DOWA F-TEC CO., LTD., DOWA ELECTRONICS MATERIALS CO., LTD.Inventors: Yasumichi Miyao, Toshiya Kitamura, Yasunobu Mishima
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Patent number: 9460850Abstract: To provide ferrite magnetic powders for bond magnet capable of surely suppressing residual hexavalent chrome, being an environmental load substance, having no adverse influence on the magnetic characteristics, which is an obstacle in use, and without damaging productivity and at a low cost. The method includes the steps of obtaining sintered powders by sintering raw material powders; wet-pulverizing the sintered powders; wet-cleaning the sintered powders; and annealing the cleaned sintered powders, wherein in the step of the wet-pulverization and in the step of wet-cleaning, generation of the hexavalent chrome, being an environmental load substance, is suppressed by performing the pulverization and cleaning while maintaining pH of a dispersion solvent at 8.5 or less, at the time of pulverization and cleaning.Type: GrantFiled: April 17, 2014Date of Patent: October 4, 2016Assignees: DOWA F-TEC CO., LTD., DOWA ELECTRONICS MATERIALS CO., LTD.Inventors: Shuichi Kohayashi, Hiroya Ikeda, Hideki Katayama, Keisuke Ayabe
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Publication number: 20140225316Abstract: To provide ferrite magnetic powders for bond magnet capable of surely suppressing residual hexavalent chrome, being an environmental load substance, having no adverse influence on the magnetic characteristics, which is an obstacle in use, and without damaging productivity and at a low cost. The method includes the steps of obtaining sintered powders by sintering raw material powders; wet-pulverizing the sintered powders; wet-cleaning the sintered powders; and annealing the cleaned sintered powders, wherein in the step of the wet-pulverization and in the step of wet-cleaning, generation of the hexavalent chrome, being an environmental load substance, is suppressed by performing the pulverization and cleaning while maintaining pH of a dispersion solvent at 8.5 or less, at the time of pulverization and cleaning.Type: ApplicationFiled: April 17, 2014Publication date: August 14, 2014Applicants: DOWA F-TEC CO., LTD., DOWA ELECTRONICS MATERIALS CO., LTD.Inventors: Shuichi KOHAYASHI, Hiroya IKEDA, Hideki KATAYAMA, Keisuke AYABE
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Patent number: 8337714Abstract: The present invention provides ferrite powders for bonded magnet capable of suppressing increase of SFD, while widening a particle size distribution for obtaining flowability and compressed density, and also capable of suppressing deterioration of orientation and magnetizability, and provides a process for a production magnetoplumbite-type ferrite powders containing an oxide of at least one or more kinds of transition metals selected from a group consisting of Zr, Ti, Zn, Co, Mn, and Ni, having a mean particle size of 0.20 ?m or more and less than 5.00 ?m, being the ferrite powders for bonded magnet with the ratio of particles having particle size of 1 ?m or less being 20 mass % or more in the magnetoplumbite-type ferrite powder size distribution obtained by a laser diffraction type particle size distribution analyzer.Type: GrantFiled: September 26, 2008Date of Patent: December 25, 2012Assignees: Dowa Electronics Materials Co., Ltd., Dowa F-Tec Co., Ltd.Inventors: Kazuyuki Nakaue, Shinichi Suenaga, Masahiro Kojima, Hiroya Ikeda, Satoru Tsuboi
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Publication number: 20100295643Abstract: The present invention provides ferrite powders for bonded magnet capable of suppressing increase of SFD, while widening a particle size distribution for obtaining flowability and compressed density, and also capable of suppressing deterioration of orientation and magnetizability, and provides a process for a production magnetoplumbite-type ferrite powders containing an oxide of at least one or more kinds of transition metals selected from a group consisting of Zr, Ti, Zn, Co, Mn, and Ni, having a mean particle size of 0.20 ?m or more and less than 5.00 ?m, being the ferrite powders for bonded magnet with the ratio of particles having particle size of 1 ?m or less being 20 mass % or more in the magnetoplumbite-type ferrite powder size distribution obtained by a laser diffraction type particle size distribution analyzer.Type: ApplicationFiled: September 26, 2008Publication date: November 25, 2010Applicants: DOWA ELECTRONICS MATERIALS CO., LTD, DOWA F-TEC CO., LTDInventors: Kazuyuki Nakaue, Shinichi Suenaga, Masahiro Kojima, Hiroya Ikeda, Satoru Tsuboi
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Publication number: 20100230630Abstract: To provide ferrite magnetic powders for bond magnet capable of surely suppressing residual hexavalent chrome, being an environmental load substance, having no adverse influence on the magnetic characteristics, which is an obstacle in use, and without damaging productivity and at a low cost. The method includes the steps of obtaining sintered powders by sintering raw material powders; wet-pulverizing the sintered powders; wet-cleaning the sintered powders; and annealing the cleaned sintered powders, wherein in the step of the wet-pulverization and in the step of wet-cleaning, generation of the hexavalent chrome, being an environmental load substance, is suppressed by performing the pulverization and cleaning while maintaining pH of a dispersion solvent at 8.5 or less, at the time of pulverization and cleaning.Type: ApplicationFiled: March 6, 2007Publication date: September 16, 2010Applicants: DOWA F-TEC CO., LTD., DOWA ELECTRONICS MATERIALS CO., LTD.Inventors: Shuichi Kohayashi, Hiroya Ikeda, Hideki Katayama, Keisuke Ayabe