Patents by Inventor Jun Hagiwara
Jun Hagiwara 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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Patent number: 10726983Abstract: A rare earth magnet capable of reducing an eddy current loss by virtue of a low-cost, simple configuration, when mounted in a motor, is to be provided. The rare earth magnet can include a magnet body that includes a rare earth element and iron; and a resistive layer formed on at least one surface of the magnet body, the resistive layer comprising a rare earth element, iron, and oxygen and having an average volume resistivity of 103 ?cm or more and a thickness of from 3 to 25 ?m.Type: GrantFiled: February 23, 2017Date of Patent: July 28, 2020Assignee: TDK CORPORATIONInventors: Jun Hagiwara, Fumitaka Baba, Makoto Iwasaki, Satoshi Koga
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Patent number: 9903009Abstract: A rare-earth element including a magnet body containing a rare-earth element, and a protective layer formed on a surface of the magnet body. The protective layer may include a first layer covering the magnet body and containing a rare-earth element, and a second layer covering the first layer and containing substantially no rare-earth element. Another protective layer in accordance may include an inner protective layer and an outer protective layer successively from the magnet body side. The outer protective layer is any of an oxide layer, a resin layer, a metal salt layer, and a layer containing an organic-inorganic hybrid compound.Type: GrantFiled: January 17, 2012Date of Patent: February 27, 2018Assignee: TDK CORPORATIONInventors: Masashi Miwa, Takeshi Sakamoto, Jun Hagiwara, Masami Mori
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Publication number: 20170278609Abstract: A rare earth magnet capable of reducing an eddy current loss by virtue of a low-cost, simple configuration, when mounted in a motor, is to be provided, where the rare earth magnet comprising: a magnet body comprising a rare earth element and iron; and a resistive layer formed on at least one surface of the magnet body, the resistive layer comprising a rare earth element, iron, and oxygen and having an average volume resistivity of 103 ?cm or more and a thickness of from 3 to 25 ?m, as is shown in FIG. 2.Type: ApplicationFiled: February 23, 2017Publication date: September 28, 2017Applicant: TDK CorporationInventors: Jun HAGIWARA, Fumitaka BABA, Makoto IWASAKI, Satoshi KOGA
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Patent number: 9773599Abstract: The present invention provides an R-T-B based sintered magnet including R2T14B crystal grains wherein; a grain boundary is formed by two or more adjacent R2T14B crystal grains, an R—O—C concentrated part, in which concentrations of R, O and C are higher than those in the R2T14B crystal grains respectively, is in the grain boundary, and a ratio (O/R) of O atom to R atom in the R—O—C concentrated part satisfies the following formula (1): 0.4<(O/R)<0.7.Type: GrantFiled: February 13, 2013Date of Patent: September 26, 2017Assignee: TDK CORPORATIONInventors: Masashi Miwa, Haruna Nakajima, Ken-ichi Nishikawa, Tetsuya Hidaka, Jun Hagiwara, Chikara Ishizaka
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Patent number: 9514869Abstract: The present invention provides an R-T-B based sintered magnet including R2T14B crystal grains wherein; a grain boundary is formed by two or more adjacent R2T14B crystal grains, an R—O—C concentrated part, in which concentrations of R, O and C are higher than those in the R2T14B crystal grains respectively, is in the grain boundary, and an area of the R—O—C concentrated part occupying in that of the grain boundary on a cut surface of the R-T-B based sintered magnet is within a range of 10% or more to 75% or less.Type: GrantFiled: February 13, 2013Date of Patent: December 6, 2016Assignee: TDK CORPORATIONInventors: Masashi Miwa, Haruna Nakajima, Ken-ichi Nishikawa, Tetsuya Hidaka, Jun Hagiwara, Chikara Ishizaka
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Publication number: 20150235750Abstract: The present invention provides an R-T-B based sintered magnet including R2T14B crystal grains wherein; a grain boundary is formed by two or more adjacent R2T14B crystal grains, an R—O—C concentrated part, in which concentrations of R, O and C are higher than those in the R2T14B crystal grains respectively, is in the grain boundary, and a ratio (O/R) of O atom to R atom in the R—O—C concentrated part satisfies the following formula (1): 0.4<(O/R)<0.7.Type: ApplicationFiled: February 13, 2013Publication date: August 20, 2015Applicant: TDK CorporationInventors: Masashi Miwa, Haruna Nakajima, Ken-ichi Nishikawa, Tetsuya Hidaka, Jun Hagiwara, Chikara Ishizaka
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Publication number: 20150155083Abstract: The present invention provides an R-T-B based sintered magnet including R2T14B crystal grains wherein; a grain boundary is formed by two or more adjacent R2T14B crystal grains, an R—O—C concentrated part, in which concentrations of R, O and C are higher than those in the R2T14B crystal grains respectively, is in the grain boundary, and an area of the R—O—C concentrated part occupying in that of the grain boundary on a cut surface of the R-T-B based sintered magnet is within a range of 10% or more to 75% or less.Type: ApplicationFiled: February 13, 2013Publication date: June 4, 2015Applicant: TDK CORPORATIONInventors: Masashi Miwa, Haruna Nakajima, Ken-ichi Nishikawa, Tetsuya Hidaka, Jun Hagiwara, Chikara Ishizaka
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Patent number: 9028981Abstract: A metal magnet 10 including a magnet body 12 and a coating layer 14 over the magnet body 12, in which the coating layer 14 has a Martens hardness of 2000 N/mm2 or more and an elastic resilience of 25% or less, and a motor including the metal magnet 10.Type: GrantFiled: June 11, 2010Date of Patent: May 12, 2015Assignee: TDK CorporationInventors: Kenichi Yoshida, Jun Hagiwara
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Patent number: 8436129Abstract: A polycarbonate resin having at least one terminal group which is represented by formula (1), and a resin composition and an optical material comprising the polycarbonate resin are disclosed. In the formula, R1-R9 each independently represent a hydrogen atom, halogen atom or an alkyl group. X1 represents a direct bond or alkylene group.Type: GrantFiled: April 23, 2009Date of Patent: May 7, 2013Assignee: Mitsubishi Gas Chemical Company, Inc.Inventors: Noriyuki Kato, Shu Yoshida, Toshiaki Yamada, Jun Hagiwara
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Patent number: 8383252Abstract: The present invention has aimed to provide a method which is capable of producing a rare earth magnet having a protective layer that can provide a sufficient water resistance. The present invention provides a method for producing a rare earth magnet comprising a magnet body containing a rare earth element and a protective layer with high water resistance formed on the surface of the magnet body, the method comprising a first step in which a zinc compound soluble in an alkaline solution is dissolved in an alkali silicate solution to prepare a treatment solution, a second step in which the treatment solution is attached on the surface of the magnet body, and a third step in which the treatment solution attached on the magnet body surface is cured to form a protective layer comprising the cured product of the treatment solution.Type: GrantFiled: September 25, 2008Date of Patent: February 26, 2013Assignee: TDK CorporationInventors: Masashi Miwa, Jun Hagiwara
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Publication number: 20120112862Abstract: A rare-earth element including a magnet body containing a rare-earth element, and a protective layer formed on a surface of the magnet body. The protective layer may include a first layer covering the magnet body and containing a rare-earth element, and a second layer covering the first layer and containing substantially no rare-earth element. Another protective layer in accordance may include an inner protective layer and an outer protective layer successively from the magnet body side. The outer protective layer is any of an oxide layer, a resin layer, a metal salt layer, and a layer containing an organic-inorganic hybrid compound.Type: ApplicationFiled: January 17, 2012Publication date: May 10, 2012Applicant: TDK CORPORATIONInventors: Masashi MIWA, Takeshi Sakamoto, Jun Hagiwara, Masami Mori
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Patent number: 8058384Abstract: The invention relates to a method for producing a thermoplastic resin, comprising using a composition at least comprising a fluorene-containing dihydroxy compound represented by the following formula (1) and a fluorene-containing hydroxy compound represented by the following formula (2) in an amount of from 0.5 parts by weight to 1.5 parts by weight relative to 100 parts by weight of the fluorene-containing dihydroxy compound of formula (1).Type: GrantFiled: October 26, 2009Date of Patent: November 15, 2011Assignee: Mitsubishi Gas Chemical Company, Inc.Inventors: Noriyuki Kato, Toshiaki Yamada, Shu Yoshida, Jun Hagiwara, Hiroki Furuhashi, Kazuaki Kaneko, Keiichi Kameyama
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Patent number: 8026336Abstract: The present invention relates to a polycarbonate resin composition which comprises a polycarbonate resin having the repeating unit that is represented by the following general formula (1) and a hydroxyl group at terminal thereof and has the concentration of the terminal hydroxyl group of 1000 ppm or more.Type: GrantFiled: February 16, 2010Date of Patent: September 27, 2011Assignee: Mitsubishi Gas Chemical Company, Inc.Inventors: Noriyuki Kato, Yoshinori Isahaya, Shu Yoshida, Jun Hagiwara, Kazuaki Kaneko, Keiichi Kameyama
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Publication number: 20110201762Abstract: To provide a polycarbonate resin composition excellent in low-birefringence and environment resistance properties to be used for optical materials such as lenses, films or sheets. Disclosed is a polycarbonate resin composition comprising a polycarbonate resin (A) prepared by forming carbonate bonds in a dihydroxy compound represented by formula (1) with a diester carbonate, and a polycarbonate resin (B) prepared by forming carbonate bonds in 2,2-bis(4-hydroxyphenyl)propane with a diester carbonate or phosgene. In the formula, R1 and R2 each independently represent a hydrogen atom or methyl.Type: ApplicationFiled: July 23, 2009Publication date: August 18, 2011Applicant: MITSUBISHI GAS CHEMICAL COMPANY, INC.Inventors: Noriyuki Kato, Toshiaki Yamada, Shu Yoshida, Jun Hagiwara, Kazuaki Kaneko
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Publication number: 20110112271Abstract: A polycarbonate resin having at least one terminal group which is represented by formula (1), and a resin composition and an optical material comprising the polycarbonate resin are disclosed. In the formula, R1-R9 each independently represent a hydrogen atom, halogen atom or an alkyl group. X1 represents a direct bond or alkylene group.Type: ApplicationFiled: April 23, 2009Publication date: May 12, 2011Applicant: MITSUBISHI GAS CHEMICAL COMPANY, INC.Inventors: Noriyuki Kato, Shu Yoshida, Toshiaki Yamada, Jun Hagiwara
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Publication number: 20100330361Abstract: A metal magnet 10 including a magnet body 12 and a coating layer 14 over the magnet body 12, in which the coating layer 14 has a Martens hardness of 2000 N/mm2 or more and an elastic resilience of 25% or less, and a motor including the metal magnet 10.Type: ApplicationFiled: June 11, 2010Publication date: December 30, 2010Applicant: TDK CORPORATIONInventors: Kenichi YOSHIDA, Jun Hagiwara
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Publication number: 20100210811Abstract: The present invention relates to a polycarbonate resin composition which comprises a polycarbonate resin having the repeating unit that is represented by the following general formula (1) and a hydroxyl group at terminal thereof and has the concentration of the terminal hydroxyl group of 1000 ppm or more.Type: ApplicationFiled: February 16, 2010Publication date: August 19, 2010Applicant: MITSUBISHI GAS CHEMICAL COMPANY, INC.Inventors: Noriyuki KATO, Yoshinori ISAHAYA, Shu YOSHIDA, Jun HAGIWARA, Kazuaki KANEKO, Keiichi KAMEYAMA
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Publication number: 20100194508Abstract: There is provided a rare-earth permanent magnet optimized to an IPM type motor for a car, capable of improving corrosion resistance, abrasion resistance, and impact resistance. The rare-earth permanent magnet 16 is configured by forming an electroplated Ni coating film 21, of which thickness is 15 ?m or more and 30 ?m or less and of which shape is a columnar crystal structure, on a surface of a R—Fe—B system permanent magnet (R is a rare-earth element) 22. The electroplated Ni coating film 21 has a high hardness region, where the Vickers hardness is 300 or more and 600 or less, and a low hardness region, where the Vickers hardness is 150 or more and 300 or less. The rare-earth permanent magnet 16 is used in a state where the rare-earth permanent magnet 16 is inserted into a slot of a yoke in a rotor of an IPM type motor for a car.Type: ApplicationFiled: January 28, 2010Publication date: August 5, 2010Inventors: Jun HAGIWARA, Takeshi Nagai, Toshiyasu Komatsu, Yasutaka Shintani, Makoto Kubota, Tadao Nishiyama, Hidenori Okada
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Publication number: 20100144995Abstract: The invention relates to a method for producing a thermoplastic resin, comprising using a composition at least comprising a fluorene-containing dihydroxy compound represented by the following formula (1) and a fluorene-containing hydroxy compound represented by the following formula (2) in an amount of from 0.5 parts by weight to 1.5 parts by weight relative to 100 parts by weight of the fluorene-containing dihydroxy compound of formula (1).Type: ApplicationFiled: October 26, 2009Publication date: June 10, 2010Applicant: MITSUBISHI GAS CHEMICAL COMPANY, INC.Inventors: Noriyuki KATO, Toshiaki Yamada, Shu Yoshida, Jun Hagiwara, Hiroki Furuhashi, Kazuaki Kaneko, Keiichi Kameyama
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Publication number: 20090087672Abstract: The present invention has aimed to provide a method which is capable of producing a rare earth magnet having a protective layer that can provide a sufficient water resistance. The present invention provides a method for producing a rare earth magnet comprising a magnet body containing a rare earth element and a protective layer with high water resistance formed on the surface of the magnet body, the method comprising a first step in which a zinc compound soluble in an alkaline solution is dissolved in an alkali silicate solution to prepare a treatment solution, a second step in which the treatment solution is attached on the surface of the magnet body, and a third step in which the treatment solution attached on the magnet body surface is cured to form a protective layer comprising the cured product of the treatment solution.Type: ApplicationFiled: September 25, 2008Publication date: April 2, 2009Applicant: TDK CORPORATIONInventors: Masashi MIWA, Jun HAGIWARA