Ferrite Core-resin Shell Carrier Patents (Class 430/111.32)
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Patent number: 11960243Abstract: An electrostatic image developer includes a toner including toner particles that include a binder resin and a release agent and have an exposure ratio of the release agent of 15% or more and 30% or less, and a carrier including magnetic particles and resin cover layers covering the magnetic particles and including inorganic particles, wherein the inorganic particles have an arithmetic average particle size of 5 nm or more and 90 nm or less, the resin cover layers have an average thickness of 0.6 ?m or more and 1.4 ?m or less, and a fine-irregularity-structure surface roughness of surfaces of the carrier three-dimensionally analyzed has, in an analysis region, a ratio B/A of an irregularity-surface area B to a plan-view area A of 1.020 or more and 1.100 or less.Type: GrantFiled: August 24, 2021Date of Patent: April 16, 2024Assignee: FUJIFILM Business Innovation Corp.Inventors: Kazutsuna Sasaki, Yasuo Kadokura, Takuro Watanabe, Karin Sakai
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Patent number: 11513447Abstract: A carrier for forming an electrophotographic image is provided. The carrier comprises a core particle and a resin layer coating the core particle. The resin layer contains a chargeable particle A, a conductive particle B, a dispersing agent, and a defoaming agent.Type: GrantFiled: November 6, 2020Date of Patent: November 29, 2022Assignee: Ricoh Company, Ltd.Inventors: Yuuya Takabayashi, Shinya Nakagawa, Katsuhiko Fujii, Junjiroh Sogame
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Patent number: 11045780Abstract: A method of encapsulating particulate materials. The method of encapsulating particulate materials may be used to multi coat a coated thermoplastic particle. The method includes providing an amount of acidified water in an amount to hydrolyze a pre-determined amount of alkoxysilane. A particulate thermoplastic material is dispersed within the acidified water. Once dispersed, an amount of alkoxysilane having a pre-determined formula is added and an amount of time is allowed to pass thereby allowing the alkoxysilane to hydrolyze and build a particle having a pre-determined particle size. Once the particle with pre-determined particle size has been obtained, the particles may be combined with alkoxysilane having a pre-determined formula and an amount of time is allowed to pass thereby allowing the alkoxysilane to hydrolyze and build a particle having a pre-determined particle size. This provides an encapsulated particulate material having one or more coatings thereon.Type: GrantFiled: December 13, 2019Date of Patent: June 29, 2021Assignee: Quadsil, Inc.Inventor: John D. Blizzard
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Patent number: 10543472Abstract: A method of encapsulating particulate materials that enables the particulate materials to be used in end use applications where they currently are not useful. The method uses specific sol gel technology to encapsulate solid particles. In addition, the method can be used to multiple coat a coated particle.Type: GrantFiled: March 25, 2016Date of Patent: January 28, 2020Inventor: John D. Blizzard
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Patent number: 10409188Abstract: Provided is a magnetic carrier comprising a magnetic carrier particle having a magnetic body-dispersed resin carrier core material and a resin coating layer; the core material includes magnetic particles A and B having number average primary particle diameter of ra and rb (?m), respectively, satisfying ra?rb; the particles A each include an oxide of at least one nonferrous metal of Mn, Al, Mg, Ti, and Ni; and an iron oxide; M1 represents total content of the nonferrous metal and F1 represents content of an iron of the magnetic carrier particle measured by XRF diffraction, M1/F1 is 0.010 to 0.100; M2 represents total content of the nonferrous metal and F2 represents content of an iron is F2 of the magnetic carrier particle measured by XPS, M2/F2 is 1.0 to 10.0.Type: GrantFiled: February 6, 2018Date of Patent: September 10, 2019Assignee: CANON KABUSHIKI KAISHAInventors: Nobuyoshi Sugahara, Hironori Minagawa, Wakashi Iida
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Patent number: 9798264Abstract: Provided is a method for producing a carrier for developing an electrostatic latent image, the carrier including carrier particles each including a core particle with a surface coated with a coating material including a resin, and the method including the steps of: a) obtaining first coating resin particles by polymerizing an alicyclic methacrylate monomer using, as a polymerization initiator, an azo compound having a nitrogen atom-containing substituent; b) obtaining second coating resin particles by polymerizing an alicyclic methacrylate monomer using a persulfate as a polymerization initiator; and c) forming carrier particles by coating surfaces of core particles with a coating material obtained by mixing at least the first and second coating resin particles.Type: GrantFiled: October 3, 2016Date of Patent: October 24, 2017Assignee: KONICA MINOLTA, INC.Inventors: Kosuke Nakamura, Satoshi Uchino, Koji Shibata
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Patent number: 9778586Abstract: The present invention provides a magnetic carrier for an electrophotographic developer which has an excellent durability and a stable charging property and is free from occurrence of spent toner thereonto, and a two-component system developer comprising the magnetic carrier for an electrophotographic developer and a toner. The present invention relates to a core material of a magnetic carrier for an electrophotographic developer comprising spherical composite particles comprising at least ferromagnetic iron oxide fine particles and a cured phenol resin and having an average particle diameter of 1 to 100 ?m, a resin index of the spherical composite particles being within the range of 35 to 80%, and a magnetic carrier obtained by coating a surface of respective particles of the magnetic carrier core material with a resin.Type: GrantFiled: April 12, 2012Date of Patent: October 3, 2017Assignee: TODA GOKYO CORPORATIONInventors: Kaori Kinoshita, Eiichi Kurita
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Patent number: 9513571Abstract: A magnetic carrier contains a resin-filled magnetic core particle and a resin covering layer provided on a surface of the resin-filled magnetic core particle. The resin-filled magnetic core particle is a porous magnetic particle containing a resin in pores thereof. The magnetic carrier has a 50% particle diameter (D50) of 30.0 ?m or more and 80.0 ?m or less on a volume basis. An electric current flowing through the magnetic carrier at a voltage of 500 V ranges from 8.0 to 50.0 ?A. A proportion JR1 of a composition that is made up of the resin in a magnetic carrier portion of a region R1 and a proportion JR2 of the composition in a magnetic carrier portion of a region R2 satisfy the following relationship. The region R1 and the region R2 are illustrated in FIG. 1. 1.20?JR2/JR1?2.00.Type: GrantFiled: May 29, 2014Date of Patent: December 6, 2016Assignee: Canon Kabushiki KaishaInventors: Nobuyoshi Sugahara, Hironori Minagawa, Yuto Onozaki, Minoru Yoshifuku, Wakashi Iida
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Patent number: 9341973Abstract: There is provided a magnetic carrier having a resin coating layer formed on the surface of each of particles prepared by putting resin in the pores of porous magnetic particles, wherein (i) the surface roughness Ra of the porous magnetic particles ranges from 0.180 ?m to 0.250 ?m, (ii) the pore size ranges from 0.40 ?m to 1.00 ?m, (iii) the amount of the resin held in the pores ranges from 3.0 parts by mass to 5.5 parts by mass relative to 100 parts by mass of the porous magnetic particles, (iv) the amount of resin used for forming the coating resin layer ranges from 1.0 parts by mass to 3.0 parts by mass relative to 100 parts by mass of the porous magnetic particles, and (v) the surface roughness Ra of the magnetic carrier ranges from 0.160 ?m to 0.220 ?m.Type: GrantFiled: May 29, 2014Date of Patent: May 17, 2016Assignee: Canon Kabushiki KaishaInventors: Minoru Yoshifuku, Wakashi Iida, Hironori Minagawa, Nobuyoshi Sugahara, Yuto Onozaki
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Patent number: 9274446Abstract: A method for manufacturing carrier core particles for electrophotographic developer that include manganese, magnesium, and iron as a core composition. The method includes a granulation step (A) of granulating a mixture of raw materials containing manganese, magnesium, and iron with a reducing agent added at a ratio of 0.10% to 1.00% by mass to a total mass of the raw materials containing manganese, magnesium, and iron, and a firing step of firing the granular material granulated in the granulation step. The firing step includes a first heating step (C) of applying heat at a constant temperature ranging from 500° C. to 800° C. in an atmosphere with an oxygen concentration of 1000 ppm to 15000 ppm for a predetermined period of time and a second heating step (D) of applying heat at a temperature higher than 800° C. for a predetermined period of time after the first heating step.Type: GrantFiled: November 30, 2012Date of Patent: March 1, 2016Assignees: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA IP CREATION CO., LTD.Inventor: Takeshi Kawauchi
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Patent number: 9268246Abstract: Provided is a method for manufacturing carrier core particles for electrophotographic developer capable of stably maintaining high chargeability over a long time. The method for manufacturing carrier core particles includes a granulation step of granulating a mixture of raw materials containing manganese, iron, strontium, and calcium and a firing step of firing the mixture granulated in the granulation step. The firing step includes a heating process of heating the granular mixture with an increase in temperature to a predetermined degree and a cooling process of cooling the granular mixture, after the heating process, in an atmosphere with an oxygen concentration ranging from 5000 ppm to 20000 ppm. The molar ratio of the sum of strontium and calcium to the sum of the manganese, iron, strontium, and calcium is 0.0026 to 0.013.Type: GrantFiled: February 20, 2014Date of Patent: February 23, 2016Assignees: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA IP CREATION CO., LTD.Inventors: Takeshi Kawauchi, Sho Ogawa, Haruka Seki
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Patent number: 9256150Abstract: A two-component developer of the present disclosure contains a carrier and toner particles. The carrier includes a carrier core, a first layer coating a surface of the carrier core, and a second layer coating a surface of the first layer. The first layer contains a fluorine-based resin, and the second layer contains a polyamide-imide resin and/or a melamine resin. The toner particles each include a toner core containing a binder resin and a shell layer coating a surface of the toner core. The shell layer contains a thermosetting resin.Type: GrantFiled: October 13, 2014Date of Patent: February 9, 2016Assignee: KYOCERA Document Solutions Inc.Inventors: Yusuke Kurano, Hiroaki Moriyama
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Patent number: 9034551Abstract: Provided is a two-component developer containing: a magnetic carrier obtained by coating a magnetic core with a resin; and toner, in which: the magnetic core contains at least a ferrite component and at least one kind of an oxide selected from the group consisting of SiO2 and Al2O3; the content of the oxide is 4.0 mass % or more and 40.0 mass % or less with respect to the magnetic core; the magnetic core has a specific resistance of 5.0×104 ?·cm or more and 5.0×108 ?·cm or less at the time of the application of 1,000 V/cm; the magnetic carrier has an intensity of magnetization in 79.6 kA/m of 40.0 Am2/kg or more and 65.0 Am2/kg or less, and a residual magnetization after the application of an external magnetic field of 79.6 kA/m of 3.0 Am2/kg or less; and the toner has a weight-average particle diameter (D4) of 3.0 ?m or more and 10.0 ?m or less and an average circularity of 0.940 or more and 0.990 or less.Type: GrantFiled: March 10, 2009Date of Patent: May 19, 2015Assignee: CANON KABUSHIKI KAISHAInventors: Tomoko Endo, Koh Ishigami, Naoki Okamoto, Yoshinobu Baba
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Patent number: 9034552Abstract: The carrier core particles for electrophotographic developer have a volume size distribution with a median particle size ranging from 30 ?m to 40 ?m, the ratio of the carrier core particles having a diameter of 22 ?m or lower in the volume size distribution is from 1.0% to 2.0%, the ratio of the carrier core particles having a diameter of 22 ?m or lower in a number size distribution is 10% or lower, and the magnetization of the carrier core particles in an external magnetic field of 1000 Oe is from 50 emu/g to 75 emu/g.Type: GrantFiled: March 1, 2012Date of Patent: May 19, 2015Assignees: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA IP CREATION CO., LTD.Inventors: Tomohide Iida, Tomoya Yamada, Takashi Fujiwara
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Patent number: 9029060Abstract: A carrier for electrostatic latent image developing is composed of carrier core containing a binder resin and magnetic material particles, and a shell layer that covers the carrier core. The binder has an acid value of at least a predetermined value, and contains a resin having a carboxyl group. The shell layer is composed of a resin selected from melamine resin and urea resin.Type: GrantFiled: September 25, 2013Date of Patent: May 12, 2015Assignee: KYOCERA Document Solutions Inc.Inventors: Masami Tujihiro, Yoshio Ozawa
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Patent number: 8945805Abstract: The present invention provides an image of high image quality by using a magnetic carrier coated with a novel coating resin composition. Further, the present invention stably provides a good image which is hardly influenced by environmental fluctuation and long-term use and has a superior stability of a charging amount when left to stand especially under high temperature and high humidity environments. The present invention also provides a magnetic carrier characterized in that a carrier core surface is coated with a copolymer containing at least, as copolymerization components, an acrylic monomer having a specific structure and an acrylic macromonomer having a specific structure.Type: GrantFiled: February 26, 2009Date of Patent: February 3, 2015Assignee: Canon Kabushiki KaishaInventors: Yoshinobu Baba, Koh Ishigami, Naoki Okamoto, Tomoko Endo
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Patent number: 8921023Abstract: Provided is a magnetic carrier excellent in leakage, uniformity of a solid image having satisfactory charging stability and developing performance at low electric field. The magnetic carrier is a magnetic carrier comprising: a magnetic substance-dispersed resin carrier core, which contains a magnetic substance and a binding resin, and a coating resin on a surface thereof, wherein: the carrier core has resistivity at 1000 V/cm of 5.0×106-8.0×107 ?·cm, the magnetic substance has a number average particle diameter of 0.20-0.35 ?m; and comprises magnetic-substance particles having vertexes and a particle diameter of 0.53 ?m or more in an amount of 10.0-32.0 vol % based on a total amount of the magnetic substance; and wherein: the carrier core has Fe2O3 content of 98.00% by mass or more; and ZnO content of 0.06-0.50% by mass.Type: GrantFiled: August 7, 2013Date of Patent: December 30, 2014Assignee: Canon Kabushiki KaishaInventors: Yoshinobu Baba, Koh Ishigami, Masayuki Hama, Kentaro Kamae, Hiroaki Kawakami
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Publication number: 20140370432Abstract: The instant disclosure describes acrylate-coated carrier resins exhibiting both high charge and improved RH sensitivity, carrier compositions comprising the acrylate coated carriers and developers comprising the carrier resins.Type: ApplicationFiled: June 14, 2013Publication date: December 18, 2014Inventors: Richard PN Veregin, Qingbin Li, Andriy Kovalenko, Sergey Gusarov, Daryl W. Vanbesien, Michael S. Hawkins
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Patent number: 8865386Abstract: A carrier core particle for an electrophotographic developer includes a core composition expressed by a general formula: MnxFe3?xO4+y (0<x?1, 0<y) as a main ingredient, 0.1 wt % or more of Si, and 0.03 wt % or more of at least one metal element selected from the group consisting of Ca, Sr and Mg.Type: GrantFiled: March 29, 2011Date of Patent: October 21, 2014Assignees: Dowa Electronics Materials Co., Ltd., Dowa IP Creation Co., Ltd.Inventors: Takeshi Kawauchi, Sho Ogawa
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Patent number: 8790858Abstract: An electrostatic charge image developing carrier has magnetic particles and a coating resin layer that coats surfaces of the magnetic particles and contains a hindered amine compound.Type: GrantFiled: August 10, 2012Date of Patent: July 29, 2014Assignee: Fuji Xerox Co., Ltd.Inventors: Toshiaki Hasegawa, Mona Tasaki, Fusako Kiyono
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Patent number: 8790615Abstract: A method of synthesizing carbon-magnetite nanocomposites. In one embodiment, the method includes the steps of (a) dissolving a first amount of an alkali salt of lignosulfonate in water to form a first solution, (b) heating the first solution to a first temperature, (c) adding a second amount of iron sulfate (FeSO4) to the first solution to form a second solution, (d) heating the second solution at a second temperature for a first duration of time effective to form a third solution of iron lignosulfonate, (e) adding a third amount of 1N sodium hydroxide (NaOH) to the third solution of iron lignosulfonate to form a fourth solution with a first pH level, (f) heating the fourth solution at a third temperature for a second duration of time to form a first sample, and (g) subjecting the first sample to a microwave radiation for a third duration of time effective to form a second sample containing a plurality of carbon-magnetite nanocomposites.Type: GrantFiled: March 22, 2011Date of Patent: July 29, 2014Assignee: Board of Trustees of the University of ArkansasInventor: Tito Viswanathan
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Patent number: 8785100Abstract: The present invention relates to a two-component developer which comprises a toner, and a carrier having a surface of a core material particle coated with a resin having a unit of general formula (1). The present invention provides a two-component developer which has enhanced environmental stability of carrier charging performance.Type: GrantFiled: December 27, 2012Date of Patent: July 22, 2014Assignee: Konica Minolta Business Technologies, Inc.Inventors: Hitomi Motani, Tomoko Mine, Tomomi Oshiba
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Patent number: 8778587Abstract: A carrier for developing an electrostatic latent image, including a particulate core material having a magnetism having developed spontaneous magnetization; and a covering layer comprising an electroconductive material, covering the surface of the particulate core material, wherein the carrier has an electrical resistivity Log R [?cm] of from 8.0 to 12.0 when measured by a method, including filling the carrier in a cell containing a pair of facing electrodes, each having a surface area of 2×4 [cm2] with a gap of 2 [mm] therebetween; and applying a DC voltage of 1,000 [V] therebetween to measure a DC resistivity, and a weight-average particle diameter (Dw) of from 25 to 45 ?m.Type: GrantFiled: October 10, 2012Date of Patent: July 15, 2014Assignee: Ricoh Company, Ltd.Inventors: Kimitoshi Yamaguchi, Shigenori Yaguchi, Toyoshi Sawada, Hiroshi Tohmatsu, Hitoshi Iwatsuki, Toyoaki Tano
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Patent number: 8765347Abstract: A two-component developing agent includes toner and a carrier including carrier particles. The toner includes a binding resin. The carrier particle includes a porous ferrite core particle and a resin covering layer. The resin covering layer covers the porous ferrite core particle. The resin covering layer includes ferrite particles. An average particle diameter of the ferrite particles ranges from 0.1 to 1.0 ?m.Type: GrantFiled: December 27, 2012Date of Patent: July 1, 2014Assignee: Konica Minolta Business Technologies, Inc.Inventors: Kosuke Nakamura, Okushi Okuyama
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Patent number: 8735041Abstract: A method for producing a low density resin-coated carrier having a small resin amount to a carrier core material and having a uniform resin coating layer formed on the carrier core material is provided. A resin-coated carrier has a carrier core material and a resin coating layer formed on the surface of the carrier core material. The carrier core material has pores and an apparent density of 1.6 g/cm3 to 2.0 g/cm3 and a remanent magnetization of 10 emu/g of less. The resin coating layer is formed by a dry process of adhering resin particles to a surface of the carrier core material and applying heat and impact force to the resin particles. A volume average particle size of the resin particles is less than 1 ?m. A two-component developer containing the resin-coated carrier is charged in a developing device in an image forming apparatus, and an image is formed.Type: GrantFiled: March 24, 2010Date of Patent: May 27, 2014Assignee: Sharp Kabushiki KaishaInventors: Takanori Kamoto, Takayuki Yamanaka, Osamu Wada, Tadashi Iwamatsu, Nobuyuki Yoshioka
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Patent number: 8728699Abstract: A porous ferrite core material for an electrophotographic developer, the porous ferrite core material including Mg in a content of 0.3 to 3% by weight, Ti in a content of 0.4 to 3% by weight and Fe in a content of 60 to 70% by weight, and the porous ferrite core material having a pore volume of 0.04 to 0.16 ml/g, a peak pore size of 0.4 to 1.6 ?m, a saturation magnetization of 40 to 80 Am2/kg, a remanent magnetization of less than 7 Am2/kg and a coercive force of less than 43 A/m; a resin-filled ferrite carrier for an electrophotographic developer obtained by filling a resin in the voids of the porous ferrite core material; and an electrophotographic developer using the ferrite carrier.Type: GrantFiled: October 19, 2010Date of Patent: May 20, 2014Assignee: Powedertech Co., Ltd.Inventors: Toru Iwata, Koji Aga
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Patent number: 8728698Abstract: The present invention is to provide a carrier and a developer, which have fewer occurrences of carrier adhesion and background smear, excellent granularity and longer durability. The carrier comprises the core material particles having magnetism and resin coating layer covering the core material particles, and wherein the weight average particle diameters is in the range of 22 m to 32 m, the proportion of the weight average particle diameters relative to the number average particle diameter is in the range of 1.00 to 1.20, the content of particles having a diameter of 20 m or smaller is 7% by mass, the content of carrier particles having a diameter of 36 m or smaller is in the range of 90% by mass to 100% by mass, and the proportion of the particle density of the core material particles is in the range of 85% to 100% of the true density of the core material particles.Type: GrantFiled: March 6, 2007Date of Patent: May 20, 2014Assignee: Ricoh Company, Ltd.Inventors: Masashi Nagayama, Kimitoshi Yamaguchi, Naoki Imahashi
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Patent number: 8722303Abstract: An image forming method using a two component developing system is provided in which a print speed is not less than 300 mm/s, a peak-to-peak voltage of an AC component in a developing bias is not more than 1.3 kV, a sufficient image density can be ensured, and a recorded image having a small amount of magnetic carrier remaining on the image and having high image quality can be obtained. A magnetic carrier that forms a two component developer contains a magnetic core and a resin. The magnetic core is a ferrite containing Sr and Ca inside thereof at the same time, having a small crystal grain diameter, a high density crystal-grain boundary structure, and an extremely large capacitance of the grain boundary. Use of the ferrite can provide the above method.Type: GrantFiled: August 24, 2012Date of Patent: May 13, 2014Assignee: Canon Kabushiki KaishaInventors: Juun Horie, Takeshi Yamamoto, Yoshinobu Baba, Koh Ishigami
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Patent number: 8697325Abstract: To provide a carrier for an electrophotographic developer in which high image quality and full colorization are possible while carrier scattering is reduced, and a method for producing the carrier, and an electrophotographic developer including the carrier. A carrier core material for an electrophotographic developer is produced so that the half-value width B of a peak having a maximum intensity in an XRD pattern satisfies B?0.160 (degree). A carrier for an electrophotographic developer and an electrophotographic developer are produced from the carrier core material for an electrophotographic developer.Type: GrantFiled: March 21, 2008Date of Patent: April 15, 2014Inventors: Tomoya Yamada, Takashi Fujiwara, Ryusuke Nakao, Yukihiro Matuda, Tomokazu Mouri
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Patent number: 8673529Abstract: The present invention relates to a magnetic carrier for an electrophotographic developer comprising spherical composite particles comprising spherical composite core particles comprising at least ferromagnetic iron oxide fine particles and a cured phenol resin and having an average particle diameter of 1 to 100 ?m, and a melamine resin coating layer formed on the respective core particles, wherein a ratio of R100 to R300 (R100/R300) in which R100 is an electric resistance value as measured when applying a voltage of 100 V to the magnetic carrier; and R300 is an electric resistance value as measured when applying a voltage of 300 V to the magnetic carrier, is controlled to lie within the range of 1 to 50.Type: GrantFiled: June 15, 2010Date of Patent: March 18, 2014Assignee: Toda Kogyo CorporationInventors: Kaori Kinoshita, Shinji Uemoto, Eiichi Kurita
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Patent number: 8663892Abstract: A latent electrostatic image developing carrier including: core particles each having magnetism; and a coating layer covering each of the core particles, wherein the latent electrostatic image developing carrier has a shape factor SF-2 of 115 to 150 and has a bulk density of 1.8 g/cm3 to 2.4 g/cm3, wherein the core particles have a shape factor SF-2 of 120 to 160 and have an arithmetic mean surface roughness Ra of 0.5 ?m to 1.0 ?m, and wherein the coating layer contains a resin and a filler and an amount of the filler contained in the coating layer is 50 parts by mass to 500 parts by mass per 100 parts by mass of the resin contained in the coating layer.Type: GrantFiled: August 23, 2012Date of Patent: March 4, 2014Assignee: Ricoh Company, Ltd.Inventors: Shigenori Yaguchi, Kimitoshi Yamaguchi, Toyoshi Sawada, Hitoshi Iwatsuki, Toyoaki Tano, Hiroshi Tohmatsu
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Patent number: 8628905Abstract: A ferrite core material for a resin-filled type carrier, and a resin-filled type carrier which is used as an electrophotographic developer by mixing a toner, sufficiently secure the image density, have no carrier adhesion and can maintain high-quality images over a long period, and an electrophotographic developer using the carrier, are provided. A ferrite core material for a resin-filled type carrier characterized in a void fraction of 10 to 60%, a resin-filled type carrier filled in the carrier core material with a resin, and an electrophotographic developer composed of the resin-filled type carrier and a toner, are provided.Type: GrantFiled: May 31, 2006Date of Patent: January 14, 2014Assignee: Powdertech Co. Ltd.Inventors: Hiromichi Kobayashi, Tsuyoshi Itagoshi, Tomoyuki Suwa, Toshio Honjo
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Patent number: 8617781Abstract: The carrier core particles 11 for electrophotographic developer contain lithium as a core composition. When the carrier core particles 11 are immersed in pure water at a weight ratio of 1 part core particles 11 to 10 parts pure water and shaken, the amount of lithium that leaches out to the pure water is 0.10 ppm or lower.Type: GrantFiled: January 25, 2011Date of Patent: December 31, 2013Assignees: Dowa Electronics Materials Co., Ltd., Dowa IP Creation Co., Ltd.Inventor: Takeshi Kawauchi
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Patent number: 8603716Abstract: An electrostatic image developing carrier includes a ferrite particle and a resin layer that coats the ferrite particle, wherein a magnesium element content of the ferrite particle is from about 3.0% by weight to about 20.0% by weight; wherein a manganese element content of the ferrite particle is from about 0.2% by weight to about 0.8% by weight; and wherein a content of toluene is more than about 100 ppm and not more than about 2,000 ppm.Type: GrantFiled: April 7, 2010Date of Patent: December 10, 2013Assignee: Fuji Xerox Co., Ltd.Inventors: Takeshi Shoji, Akihiro Iizuka, Yosuke Tsurumi, Fusako Kiyono
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Patent number: 8592123Abstract: To provide a carrier for electrophotographic developer, capable of realizing a high image quality and full colorization and reducing carrier scattering, and a manufacturing method of the same, and an electrophotographic developer containing the carrier. A carrier core material for electrophotographic developer, with a general formula expressed by MgxMn(1-x)FeyO4 (where 0<x<1, and 1.6?y?2.4), wherein a half-value width B of a peak having a maximum intensity in a powder XRD pattern satisfies B?0.180 (degree), is manufactured and from this carrier core material for electrophotographic developer, the carrier for electrophotographic developer and the electrophotographic developer are manufactured.Type: GrantFiled: April 9, 2008Date of Patent: November 26, 2013Assignees: Dowa Electronics Materials Co., Ltd., Dowa IP Creation Co., Ltd.Inventors: Tomoya Yamada, Takashi Fujiwara, Ryusuke Nakao, Yukihiro Matuda, Tomokazu Mouri
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Patent number: 8580475Abstract: An electrostatic charge image developing carrier includes a core particle and a coating layer with which the surface of the core particle is coated. The coating layer includes an acrylic resin having a constituent unit in which a silicone chain is disposed in a branch.Type: GrantFiled: October 27, 2011Date of Patent: November 12, 2013Assignee: Fuji Xerox Co., Ltd.Inventors: Takeshi Shoji, Toshiaki Hasegawa
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Patent number: 8535867Abstract: There is provided a ferrite core material for an electrophotographic developer, the ferrite core material having a ferrite particle composition represented by the formula (1) shown below, containing SrO replacing a part of (MnO) and/or (MgO) in the formula (1) shown below, and having a Cl concentration of 0.1 to 100 ppm, as measured by an elution method of the ferrite core material: (MnO)x(MgO)y(Fe2O3)z??(1) wherein x=35 to 45 mol %, y=5 to 15 mol %, z=40 to 60 mol %, and x+y+z=100 mol %.Type: GrantFiled: February 3, 2011Date of Patent: September 17, 2013Assignee: Powdertech Co., Ltd.Inventors: Tomoyuki Suwa, Toru Iwata, Koji Aga
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Patent number: 8507169Abstract: A two-component developer is disclosed, composing a toner comprising parent toner particles with an attached external additive and a carrier provided with a resin covering layer on a surface of a core particle, wherein the resin covering layer comprises a binder resin comprising an acrylic resin and when the resin covering layer is divided in half to a core particle side and a surface side, a nitrogen element content of the core particle side is larger than a nitrogen element content of the surface side.Type: GrantFiled: February 28, 2012Date of Patent: August 13, 2013Assignee: Konica Minolta Business Technologies, Inc.Inventors: Tomoko Mine, Mikihiko Sukeno, Tatsuya Nagase, Tomomi Oshiba, Hiroyuki Kozuru, Saburou Hiraoka, Yoshiyasu Matsumoto, Kosuke Nakamura, Hitomi Motani, Takanari Kayamori
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Patent number: 8486600Abstract: A carrier for developing an electrostatic charge image, including a core, and a coating layer including a resin and inorganic oxide particles that exhibit electroconductivity, by which the core is coated, wherein the inorganic oxide particles have, when they are aggregated, an aggregation size of, or when they are not aggregated, a primary particle size of, from 230 nm to 970 nm.Type: GrantFiled: February 24, 2011Date of Patent: July 16, 2013Assignee: Fuji Xerox Co., Ltd.Inventors: Norihito Fukushima, Akihiro Iizuka, Yosuke Tsurumi, Takahiro Yamashita, Shintaro Anno, Yasuaki Hashimoto
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Publication number: 20130171559Abstract: A two-component developing agent includes toner and a carrier including carrier particles. The toner includes a binding resin. The carrier particle includes a porous ferrite core particle and a resin covering layer. The resin covering layer covers the porous ferrite core particle. The resin covering layer includes ferrite particles. An average particle diameter of the ferrite particles ranges from 0.1 to 1.0 ?m.Type: ApplicationFiled: December 27, 2012Publication date: July 4, 2013Applicant: KONICA MINOLTA BUSINESS TECHNOLOGIES, INC.Inventors: Kosuke NAKAMURA, Okushi OKUYAMA
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Patent number: 8475988Abstract: Disclosed are a resin-filled ferrite carrier core material for an electrophotographic developer, including a porous ferrite particle, wherein the composition of the porous ferrite particle is represented by the following formula (1), and part of (MgO) and/or (Fe2O3) in the following formula (1) is replaced with SrO; a ferrite carrier obtained by filling a resin in the voids of the ferrite carrier core material; and an electrophotographic developer using the ferrite carrier: ( MgO ) ? x ? ( Fe 2 ? O 3 ) ? y ? ( x = 10 ? ? mol ? ? % ? ? or ? ? more ? ? and ? ? less ? ? than ? ? 25 ? ? mol ? ? % y = exceeding ? ? 75 ? ? mol ? ? % ? ? and ? ? 90 ? ? mol ? ? % ? ? or ? ? less x + y = 100 ? ? mol ? ? % ) .Type: GrantFiled: February 2, 2011Date of Patent: July 2, 2013Assignee: Powdertech Co., Ltd.Inventors: Takao Sugiura, Takashi Hikichi, Hiromichi Kobayashi
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Patent number: 8465898Abstract: There are provided a ferrite carrier core material for an electrophotographic developer, which contain 10 to 30% by weight of Mn, 1.0 to 3.0% by weight of Mg, 0.3 to 1.5% by weight of Ti and 40 to 60% by weight of Fe, a ferrite carrier for an electrophotographic developer obtained by coating the ferrite core material, and an electrophotographic developer using the ferrite carrier.Type: GrantFiled: June 16, 2011Date of Patent: June 18, 2013Assignee: Powdertech Co., Ltd.Inventors: Toru Iwata, Koji Aga
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Patent number: 8431312Abstract: The present invention provides a carrier which includes core material particles, and a coating layer on surfaces of the core material particles, wherein the coating layer contains a crosslinked product which is obtained by condensation of a silicone resin with an organic zirconium catalyst, the silicone resin having at least one of a silanol group and a functional group capable of generating a silanol group by means of hydrolysis.Type: GrantFiled: November 10, 2009Date of Patent: April 30, 2013Assignee: Ricoh Company, Ltd.Inventors: Minoru Masuda, Kimitoshi Yamaguchi, Yutaka Takahashi, Koichi Sakata, Hitoshi Iwatsuki
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Patent number: 8409778Abstract: A resin coated carrier is provided that can stably charge a toner having added thereto an external additive having a large particle size over a long period of time and can prevent blocking of a developer. The resin coated carrier satisfies the following formula (1): log(Mb/Ma)>2??(1) in which Ma is a weight average molecular weight of a silicone resin having the minimum weight average molecular weight, contained in a resin coating layer, and Mb is a weight average molecular weight of a silicone resin having the maximum weight average molecular weight, and the following formula (2) is satisfied: 0.5??log(A/B)?2.5??(2) in which A is a volume resistance (?/cm) under electric field of 1,000 V/cm obtained by conducting a stirring test, and B is a volume resistance (?/cm) under electric field of 1,000 V/cm before the stirring test.Type: GrantFiled: January 21, 2010Date of Patent: April 2, 2013Assignees: Sharp Kabushiki Kaisha, Kanto Denka Kogyo Co., Ltd.Inventors: Osamu Wada, Tadashi Iwamatsu, Takanori Kamoto, Nobuyuki Yoshioka, Natsuki Matsuura, Nobuhiro Seki, Masatomo Hayashi
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Patent number: 8389191Abstract: The present disclosure provides carriers for use with toner compositions. In embodiments, a carrier may include a core, having a dry powder polymer coating. The polymer coating possesses a carbon to oxygen from about 3:1 to about 8:1. In embodiments, the coating may also include a colorant, such as carbon black. Processes for coating such carriers with the dry powder polymer coatings are also provided.Type: GrantFiled: October 22, 2009Date of Patent: March 5, 2013Assignee: Xerox CorporationInventors: Daryl W. Vanbesien, Michael S. Hawkins, Suxia Yang, Richard P. N. Veregin, Karen Ann Moffat
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Patent number: 8383308Abstract: A positively chargeable two-component developer, including at least a toner and a carrier, wherein the toner contains a binder resin, a colorant, a wax, and a charge control agent, the binder resin contains at least a polyester resin and an addition polymerization resin grafted with a polyolefin, the wax and the addition polymerization resin grafted with a polyolefin are contained at a wax:addition polymerization resin grafted with a polyolefin ratio of from about 40:60 to about 80:20, and the carrier is a magnetic powder having a coating layer containing a methyl-containing silicone resin.Type: GrantFiled: October 29, 2008Date of Patent: February 26, 2013Assignee: Fuji Xerox Co., Ltd.Inventors: Sakon Takahashi, Daisuke Ishizuka, Michio Take, Seijiro Ishimaru, Chiaki Suzuki
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Patent number: 8357480Abstract: There are provided a carrier which enables stable charging of toner and formation of a stable, high-definition and high-quality image which has very few image defects such as a fog, as well as a developer, a developing apparatus, and an image forming apparatus. A carrier is obtained by including a carrier core and a coating layer with which a surface of the carrier core is coated, the coating layer being obtained by curing a resin composition for coating that includes a crosslinked silicone-modified acrylic resin containing a macromonomer represented by the following general formula (1). A developer is obtained by such a carrier and a toner.Type: GrantFiled: March 6, 2009Date of Patent: January 22, 2013Assignee: Sharp Kabushiki KaishaInventor: Takanori Kamoto
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Patent number: 8354214Abstract: The present disclosure provides carriers for use with toner compositions. In embodiments, a carrier may include a core, having a dry powder polymer coating. In embodiments, the coating may also include a colorant, such as carbon black. Processes for coating such carriers with the dry powder polymer coatings are also provided.Type: GrantFiled: September 21, 2009Date of Patent: January 15, 2013Assignee: Xerox CorporationInventors: Daryl W. Vanbesien, Michael S. Hawkins, Suxia Yang, Richard P. N. Veregin, Karen Ann Moffat
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Patent number: 8338067Abstract: An electrostatic image developer is provided, the electrostatic image developer including: a carrier for an electrostatic image developer, the carrier including a core particle which has a plurality of projections on a surface of the core particle; and electrostatic image developing toners, wherein the electrostatic image developer satisfies following relationships of formulae (1) and (2): 0.5t<H??(1) 21/2t<L<5t??(2) wherein t represents a volume average particle diameter (?m) of the toners; H represents an average height difference (?m) in the recesses and projections of the core particle; and L represents an average distance (?m) between the projections.Type: GrantFiled: March 26, 2010Date of Patent: December 25, 2012Assignee: Fuji Xerox Co., Ltd.Inventors: Susumu Yoshino, Hideo Maehata, Satoshi Hiraoka
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Patent number: 8309293Abstract: The present disclosure provides carriers for use with toner compositions. In embodiments, a carrier may include a core, having a dry powder polymer coating. In embodiments, the coating may also include a colorant, such as carbon black. Processes for coating such carriers with the dry powder polymer coatings are also provided.Type: GrantFiled: September 21, 2009Date of Patent: November 13, 2012Assignee: Xerox CorporationInventors: Daryl W. Vanbesien, Michael S. Hawkins, Corey L. Tracy, Richard P. N. Veregin, Karen Ann Moffat, Biby Esther Abraham