-
71.发明公开公开(公告)号：US20240254004A1
公开(公告)日：2024-08-01
申请号：US18564394
申请日：2022-05-27
Applicant: POWDERTECH CO., LTD.
Inventor： Yuzuru YAMASAKI , Makoto ISHIKAWA , Tetsuya UEMURA
CPC classification number: C01G49/009 , G03G9/108 , G03G9/1132 , C01P2006/10 , C01P2006/42
Abstract: A ferrite particle having a spinel crystal structure belonging to a space group Fd-3m and having a ferrite composition represented by a specific formula, a carrier for an electrophotographic developer including the ferrite particle and a resin coating layer configured to coat a surface of the ferrite particle, an electrophotographic developer including the carrier for an electrophotographic developer and a toner, and a ferrite particle production method for producing the ferrite particle.
-
公开(公告)号：US20230144641A1
公开(公告)日：2023-05-11
申请号：US17915348
申请日：2021-03-17
Applicant: POWDERTECH CO.,LTD.
Inventor： Makoto ISHIKAWA , Tetsuya UEMURA
CPC classification number: G03G9/1085 , G03G9/1132
Abstract: The present invention relates to a ferrite particle containing a crystal phase component containing a perovskite crystal represented by a compositional formula: RZrO3 (provided that R represents an alkaline earth metal element), having a surface roughness Rz of 2.0 μm or more and 4.5 μm or less, and satisfying the following formulas: 6.5≤log H1000≤8.5 and 0.80≤log H1000/log H100≤1.00. The ferrite particle can be used as an electrophotographic developer carrier core material. In addition, an electrophotographic developer carrier and an electrophotographic developer can be obtained.
-
公开(公告)号：US20230085745A1
公开(公告)日：2023-03-23
申请号：US17795382
申请日：2021-01-27
Applicant: POWDERTECH CO., LTD.
Inventor： Koji AGA , Takashi KOJIMA , Takao SUGIURA , Sho KUWAHARA , Satomi KONNO , Tadashi TSUDUKI
Abstract: Provided are a ferrite powder capable of maintaining a high withstand voltage even when used in a resin composition having high magnetic properties and electrical resistivity and a high filling ratio, and a method for producing the same. A ferrite powder composed of spherical ferrite particles, wherein the ferrite powder contains iron (Fe): 55.0-70.0 mass % and manganese (Mn): 3.5-18.5 mass %, the ferrite powder containing more than 0.0 mass % to 7.5 mass % α-Fe2O3, and the ferrite powder has a volume average particle size (D50) of 15.0 μm or less.
-
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
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：US11422480B2
公开(公告)日：2022-08-23
申请号：US16492894
申请日：2018-03-29
Applicant: POWDERTECH CO., LTD.
Inventor： Makoto Ishikawa , Hiroki Sawamoto , Tetsuya Uemura
Abstract: The present invention provides: a ferrite carrier core material for an electrophotographic developer, the material having a mesh passing amount of 3 wt % or less as indicated by the ratio of the weight of particles passing through a 16 μm-mesh to the weight of whole particles constituting a powder, and having a particle strength index of 2 wt % or less as indicated by a difference between the mesh passing amounts before and after crushing; a ferrite carrier which is for an electrophotographic developer and in which the surface of the ferrite carrier core material is coated with a resin; and an electrophotographic developer which includes the ferrite carrier and a toner.
-
Patent Agency Ranking
公开(公告)号：US11359689B2
公开(公告)日：2022-06-14
申请号：US16466427
申请日：2017-12-12
Applicant: POWDERTECH CO., LTD.
Inventor： Koji Aga , Takashi Kojima
Abstract: Provided is an iron oxide powder for a brake friction material which can be suitably used in a brake friction material that is less likely to cause problems regarding brake squealing and that provides superior braking performance. The iron oxide powder for a brake friction material according to a first embodiment of the present invention is characterized by having a sulfur content of 150 ppm or less as measured by combustion ion chromatography, and a saturation magnetization of 20 emu/g or less. The iron oxide powder for a brake friction material according to a second embodiment of the present invention is characterized by having an average particle size of 1.0 μm or more, a chlorine content of 150 ppm or less as measured by combustion ion chromatography, and a saturation magnetization of 20 emu/g or less.
-
公开(公告)号：US20220163082A1
公开(公告)日：2022-05-26
申请号：US17666140
申请日：2022-02-07
Applicant: POWDERTECH CO., LTD.
Inventor： Koji AGA , Takashi KOJIMA
Abstract: Provided is an iron oxide powder for a brake friction material which can be suitably used in a brake friction material that is less likely to cause problems regarding brake squealing and that provides superior braking performance. The iron oxide powder for a brake friction material according to a first embodiment of the present invention is characterized by having a sulfur content of 150 ppm or less as measured by combustion ion chromatography, and a saturation magnetization of 20 emu/g or less. The iron oxide powder for a brake friction material according to a second embodiment of the present invention is characterized by having an average particle size of 1.0 μm or more, a chlorine content of 150 ppm or less as measured by combustion ion chromatography, and a saturation magnetization of 20 emu/g or less.
-
公开(公告)号：US11099495B2
公开(公告)日：2021-08-24
申请号：US16641987
申请日：2018-03-06
Applicant: POWDERTECH CO., LTD.
Inventor： Hiroki Sawamoto , Tetsuya Uemura
Abstract: To provide a magnetic core material and carrier for electrophotographic developer, which have small environmental dependence of the electric resistance, can suppress the carrier scattering, and can stably provide good images; a developer contains the carrier; and methods for producing them. The magnetic core material satisfying a value of Formula (1): a+b×10+c+d+e+f, being from 20 to 150, when a fluoride ion amount is denoted by a (ppm), a chloride ion amount is denoted by b (ppm), a bromide ion amount is denoted by c (ppm), a nitrite ion amount is denoted by d (ppm), a nitrate ion amount is denoted by e (ppm), and a sulfate ion amount is denoted by f (ppm), which are measured by a combustion ion chromatography method.
-
公开(公告)号：US11032955B2
公开(公告)日：2021-06-08
申请号：US16094081
申请日：2017-04-05
Applicant: POWDERTECH CO., LTD.
Inventor： Koji Aga , Tetsuya Igarashi
Abstract: The present invention provides a powdered ferrite having high dispersibility in a resin and high electromagnetic shielding characteristics. The powdered ferrite comprises platy ferrite particles having a spinel crystal structure. The powdered ferrite comprises at least 50 number % platy ferrite particles each having at least one protrusion on a surface of the particle, and the protrusion has a shape selected from the group consisting of a rectangular pyramid, a truncated rectangular pyramid, an elongated rectangular pyramid, and combinations thereof.
-
公开(公告)号：US11029618B2
公开(公告)日：2021-06-08
申请号：US16059405
申请日：2018-08-09
Applicant: POWDERTECH CO., LTD.
Inventor： Aya Sakuta , Makoto Ishikawa , Hiroki Sawamoto , Tetsuya Uemura
IPC: G03G9/113
Abstract: There is provided a carrier including a magnetic core material having a surface coated with a surfactant-containing resin mixture of an elemental fluorine-containing resin and a polyimide resin. The carrier has an elution amount of an eluted material into water in an elution test ranging from 180 ppm to 3,500 ppm.
-
-
-
-
-
-
-
-
-
Search Results
99
records
(took 0.019 seconds)
