公开(公告)号：US11952286B2

公开(公告)日：2024-04-09

申请号：US16967197

申请日：2019-02-06

Applicant: POWDERTECH CO., LTD.

Inventor： Koji Aga ,  Takashi Kojima ,  Kazutaka Ishii ,  Tetsuya Igarashi ,  Sho Kuwahara

IPC: C01G49/00 ,  C08K3/22 ,  C08L29/04 ,  H01F1/34 ,  H01F1/37 ,  H05K9/00

CPC classification number: C01G49/0072 ,  C08L29/04 ,  H01F1/344 ,  H01F1/37 ,  H05K9/0081 ,  C01P2004/32 ,  C01P2004/51 ,  C01P2004/61 ,  C01P2006/11 ,  C01P2006/12 ,  C08K3/22 ,  C08K2201/005 ,  C08K2201/006 ,  C08K2201/01

Abstract: Provided are: an Mn ferrite powder characterized by including a plurality of ferrite particles, having a volume-average particle diameter of 1-10 μm, and having a 2.106 μm volume-based cumulative distribution (sieved) of 0.1-50.0 vol %; and a resin composition characterized by including said powder and a resin material.

公开(公告)号：US10775711B2

公开(公告)日：2020-09-15

申请号：US16084420

申请日：2017-03-29

Applicant: POWDERTECH CO., LTD.

Inventor： Takao Sugiura ,  Kazutaka Ishii ,  Koji Aga

IPC: G03G9/107 ,  G03G9/113 ,  C01G49/00 ,  G03G9/08

Abstract: An object of the present invention is to provide a ferrite carrier core material for an electrophotographic developer having desired resistance properties and charging properties with small environmental variation of resistivity and charge amount while maintaining the advantages of ferrite carriers, a ferrite carrier for an electrophotographic developer, an electrophotographic developer using the ferrite carrier, and a method for manufacturing the ferrite carrier core material for an electrophotographic developer. In order to solve the problem, a ferrite carrier core material comprising ferrite particles containing 15 mass % or more and 25 mass % or less of Mn, 0.5 mass % or more and 5.0 mass % or less of Mg, 0.05 mass % or more and 4.0 mass % of Sr, and 45 mass % or more and 55 mass % or less of Fe, with Si localized in the surface thereof is used.

公开(公告)号：US11651881B2

公开(公告)日：2023-05-16

申请号：US16650647

申请日：2018-09-27

Applicant: POWDERTECH CO., LTD.

Inventor： Takashi Kojima ,  Kazutaka Ishii ,  Takao Sugiura ,  Tetsuya Igarashi ,  Koji Aga

IPC: H01F1/34 ,  H01F1/33 ,  H01F1/37 ,  H01F27/255 ,  C01G49/00 ,  C30B29/22

CPC classification number: H01F1/344 ,  C01G49/009 ,  C01G49/0072 ,  C30B29/22 ,  H01F1/33 ,  H01F1/37 ,  C01P2004/04 ,  C01P2004/32 ,  C01P2004/61 ,  C01P2004/62 ,  C01P2004/64 ,  C01P2006/42 ,  H01F27/255 ,  Y10T428/32

Abstract: Mn—Zn ferrite particles according to the present invention contain 44-60% by mass of Fe, 10-16% by mass of Mn and 1-11% by mass of Zn. The ferrite particles are single crystal bodies having an average particle diameter of 1-2,000 nm, and have polyhedral particle shapes, while having an average sphericity of 0.85 or more but less than 0.95.

公开(公告)号：US11521768B2

公开(公告)日：2022-12-06

申请号：US16496357

申请日：2018-03-30

Applicant: POWDERTECH CO., LTD.

Inventor： Kazutaka Ishii ,  Koji Aga ,  Takao Sugiura ,  Takashi Kojima

IPC: H01F1/11 ,  B29C41/08 ,  G11B5/706 ,  G11B5/714 ,  H01F1/113

Abstract: The ferrite powder of the present invention is a ferrite powder containing a plurality of ferrite particles, wherein the ferrite particles each are a single crystal body having an average particle diameter of 1-2,000 nm, and have a polyhedron shape, and wherein the ferrite particles each contain 2.0-10.0 mass % of Sr, and 55.0-70.0 mass % of Fe.

公开(公告)号：US10825593B2

公开(公告)日：2020-11-03

申请号：US16336644

申请日：2017-06-07

Applicant: POWDERTECH CO., LTD.

Inventor： Takashi Kojima ,  Kazutaka Ishii ,  Takao Sugiura ,  Tetsuya Igarashi ,  Koji Aga

IPC: H01F1/375 ,  C22C38/08 ,  C22C38/16 ,  G03G9/107

Abstract: An object of the present invention is to provide ferrite particles having high saturation magnetisation and electrical resistivity, excellent in dispersibility in a resin, a solvent, or a resin composition; a rein composition containing the ferrite particles; and a resin molding composed of the resin composition. A Ni-Zn-Cu ferrite particle is in a single crystalline body having an average particle diameter of 1 to 2000 nm, has a polyhedral particle shape, and comprises 5 to 10 wt % of Ni, 15 to 30 wt % of Zn, 1 to 5 wt % of Cu, and 25 to 50 wt % of Fe.

公开(公告)号：US11542174B2

公开(公告)日：2023-01-03

申请号：US16307794

申请日：2017-05-31

Applicant: POWDERTECH CO., LTD.

Inventor： Takashi Kojima ,  Kazutaka Ishii ,  Takao Sugiura ,  Tetsuya Igarashi ,  Koji Aga

IPC: C01G49/00 ,  C08K3/22 ,  C08K7/18 ,  C30B29/22 ,  C30B29/60 ,  H01F1/34 ,  H05K9/00

Abstract: An object of the present invention is to provide ferrite particles having a high magnetic permeability in a frequency band of 1 MHz to 1 GHz. Another object is to provide a resin composition containing the ferrite particles and an electromagnetic wave shielding material composed of the resin composition. The ferrite particles are composed of a single crystalline body having an average particle size of 1 to 2000 nm and has a spherical particle shape, wherein the ferrite particles contain substantially no Zn, 3 to 25 wt % of Mn, and 43 to 65 wt % of Fe, and a real part μ′ of a complex magnetic permeability measured using a molding composed of the ferrite particles and a binder resin has a maximal value in a frequency band of 100 MHz to 1 GHz.

公开(公告)号：US11014826B2

公开(公告)日：2021-05-25

申请号：US16082102

申请日：2017-02-22

Applicant: POWDERTECH CO., LTD.

Inventor： Takashi Kojima ,  Kazutaka Ishii ,  Takao Sugiura ,  Tetsuya Igarashi ,  Koji Aga

IPC: H01F1/36 ,  H01F1/37 ,  H01F1/375 ,  C01G49/00 ,  C08K3/22 ,  C08L101/00 ,  C30B29/22 ,  C08K7/18 ,  H05K1/02 ,  H05K1/03

Abstract: An object of the present invention is to provide ferrite particles having a high saturation magnetisation, and being excellent in the dispersibility in a resin, a solvent or a resin composition, a resin composition including the ferrite particles, and a resin film composed of the resin composition. The ferrite particles are a single crystalline body having an average particle size of 1 to 2000 nm, and Mn-based ferrite particles having a spherical shape, and have a saturation magnetisation of 45 to 95 Am2/kg. The resin composition includes the ferrite particles as a filler. The resin film is composed of the resin composition.

公开(公告)号：US10564561B2

公开(公告)日：2020-02-18

申请号：US16084466

申请日：2017-03-29

Applicant: POWDERTECH CO., LTD.

Inventor： Takao Sugiura ,  Kazutaka Ishii ,  Koji Aga

IPC: G03G9/113 ,  G03G9/107 ,  G03G9/093

Abstract: An object of the present invention is to provide a ferrite carrier core material for an electrophotographic developer having desired resistance properties and charging properties with small environmental variation of resistivity and charge amount while maintaining the advantages of ferrite carriers, a ferrite carrier for an electrophotographic developer, an electrophotographic developer using the ferrite carrier, and a method for manufacturing the ferrite carrier core material for an electrophotographic developer. In order to solve the problem, a ferrite carrier core material comprising ferrite particles containing 15 mass % or more and 25 mass % or less of Mn, 0.5 mass % or more and 5.0 mass % or less of Mg, 0.05 mass % or more and 4.0 mass % of Sr, and 45 mass % or more and 55 mass % or less of Fe, with Zr localized in the surface thereof is used.