Chemically Identified Carrier For Dry Toner Patents (Class 430/111.1)
  • Publication number: 20140072910
    Abstract: A carrier for developing an electrostatic latent image of the present invention includes a core material and a coating layer which coats the core material, wherein the coating layer includes a resin and fine particles, wherein the coating layer has an average layer thickness difference of 0.02 ?m to 3.0 ?m, and wherein the carrier for developing an electrostatic latent image has an arithmetic mean surface roughness Ra1 of 0.5 ?m to 0.9 ?m.
    Type: Application
    Filed: June 26, 2013
    Publication date: March 13, 2014
    Inventors: Hitoshi IWATSUKI, Shigenori Yaguchi, Toyoaki Tano, Mariko Takii, Koichi Sakata, Hiroyuki Kishida, Hiroshi Tohmatsu
  • Patent number: 8652735
    Abstract: A carrier including a magnetic core particle and a resin layer covering a surface of the magnetic core particle. The magnetic core particle is a ferrite particle including strontium in an amount of 0.005 to 3% by mass, measured by fluorescent X-ray spectroscopy. The resin layer comprises a resin obtained by heating a copolymer comprising a silicon-containing unit A and another silicon-containing specific unit B.
    Type: Grant
    Filed: August 19, 2011
    Date of Patent: February 18, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Koichi Sakata, Shigenori Yaguchi, Toyoshi Sawada, Kimitoshi Yamaguchi, Hitoshi Iwatsuki, Hiroshi Tohmatsu, Hiroyuki Kishida, Toyoaki Tano, Mariko Takii
  • Patent number: 8652736
    Abstract: The present invention provides a carrier core material for use in the production of an electrophotographic developer which, even when applied, for example, to MFPs (multifunction printers), can realize stable, high-quality and high-speed development, and has a prolonged replacing life of magnetic carriers, and a method of manufacturing the same, a magnetic carrier including the carrier core material, and an electrophotographic developer manufactured from the magnetic carrier. An electrophotographic development carrier is prepared by adding resin particles, a binder, a dispersant, a wetting agent, and water to a raw material powder, wet pulverizing the mixture, drying the pulverized product to give granulated powder, calcinatng the granulated powder, and then sintering the granulated powder to prepare a carrier core material having an internally hollow structure, and coating the carrier core material with a resin.
    Type: Grant
    Filed: September 25, 2006
    Date of Patent: February 18, 2014
    Assignees: Dowa IP Creation Co., Ltd., Dowa Electronics Materials Co., Ltd.
    Inventors: Ryusuke Nakao, Takeshi Kawauchi
  • Publication number: 20140023966
    Abstract: A carrier for developing electrostatic latent images includes a core material; and a covering layer formed of a resin comprising an electroconductive particulate material, overlying the core material, wherein the covering layer includes the electroconductive particulate material in an amount of from 58 to 73% by weight and has a resistivity of from 6.6 to 8.6 ?cm, and wherein the carrier has a high-brightness contrast part at an areal ratio less than 1% and 40 to 90% based on total area thereof at an acceleration voltage of 0.8 KV and 2.0 KV, respectively in an FE-SEM reflection electron image of the surface thereof.
    Type: Application
    Filed: July 1, 2013
    Publication date: January 23, 2014
    Inventors: Toyoshi SAWADA, Shigenori Yaguchi, Hiroshi Tohmatsu, Hitoshi Iwatsuki, Toyoaki Tano, Hiroyuki Kishida, Yumiko Yagi
  • Patent number: 8617781
    Abstract: 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: Grant
    Filed: January 25, 2011
    Date of Patent: December 31, 2013
    Assignees: Dowa Electronics Materials Co., Ltd., Dowa IP Creation Co., Ltd.
    Inventor: Takeshi Kawauchi
  • Patent number: 8518626
    Abstract: The carrier is used for a two-component developer for developing an electrostatic latent image, and includes a particulate magnetic core material; and a cover layer located on a surface of the particulate magnetic core material and including a crosslinked material. The crosslinked material is formed by hydrolyzing a copolymer including at least a unit (A) having a specific acrylic siloxane structure including a tris(trialkylsiloxy)silanyl group and a unit (B) having a specific acrylic silicone structure to form a material having a silanol group, and subjecting the material having a silanol group to a condensation reaction using an organic zirconium-containing catalyst.
    Type: Grant
    Filed: March 1, 2011
    Date of Patent: August 27, 2013
    Assignee: Ricoh Company, Limited
    Inventors: Saori Yamada, Minoru Masuda, Hisashi Nakajima, Kimitoshi Yamaguchi, Koichi Sakata, Hitoshi Iwatsuki, Yutaka Takahashi, Toyoaki Tano, Mariko Takii
  • Patent number: 8512929
    Abstract: A latent electrostatic image developing carrier including a carrier core material, and a coating layer containing a resin and provided on a surface of the carrier core material, wherein the coating layer includes a particulate material containing at least first fine conductive particles and second fine conductive particles, and wherein the first fine conductive particles and the second fine conductive particles satisfy the relationships expressed by Expressions 1 and 2, 3?D1/D2?15 . . . Expression 1, where D1 denotes a dispersed particle diameter of the first fine conductive particles and D2 denotes a dispersed particle diameter of the second fine conductive particles, and ?7E?R1×R2?8E . . . Expression 2, where R1 denotes a powder specific resistance of the first fine conductive particles and R2 denotes a powder specific resistance of the second fine conductive particles.
    Type: Grant
    Filed: September 10, 2010
    Date of Patent: August 20, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Hitoshi Iwatsuki, Kimitoshi Yamaguchi, Minoru Masuda, Yutaka Takahashi, Koichi Sakata, Toyoaki Tano
  • Patent number: 8512927
    Abstract: An electrostatic image developing carrier including at least a core material and a coating resin layer which coats the surface of the core material, the resin layer comprising a thermoplastic resin having an alicyclic group, a thermal reduction in accordance with the TGA method being in the range of 0.5 weight % to 5 weight % of the whole of the carrier in the range of 100° C. to 400° C., and further an endothermic quantity of the whole of the carrier in accordance with the DTA method is in the range of 7 mJ/g to 40 mJ/g in the range of 100° C. to 400° C.
    Type: Grant
    Filed: April 4, 2007
    Date of Patent: August 20, 2013
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Akihiro Iizuka, Fusako Kiyono, Tsuyoshi Murakami
  • Patent number: 8512928
    Abstract: A carrier comprising a magnetic core particle having a shape factor SF-2 of 130 to 160 and a resin layer covering a surface of the magnetic core particle. The resin layer comprises a conductive particle and a resin obtained by heating a copolymer comprising a silicon-containing A unit and another silicon-containing B unit.
    Type: Grant
    Filed: September 6, 2011
    Date of Patent: August 20, 2013
    Assignee: Rocoh Company, Ltd.
    Inventors: Hiroyuki Kishida, Shigenori Yaguchi, Kimitoshi Yamaguchi, Toyoshi Sawada, Hiroshi Tohmatsu, Koichi Sakata, Hitoshi Iwatsuki, Toyoaki Tano, Mariko Takii
  • Publication number: 20130189614
    Abstract: A carrier core particle for an electrophotographic developer including a core composition expressed by a general formula: (MnxMgyCaz) FeWO4+V (x+y+z+w=3, ?0.003<v) as a main ingredient, wherein 0.05?y?0.35 and 0.005?z?0.024.
    Type: Application
    Filed: July 26, 2011
    Publication date: July 25, 2013
    Applicants: DOWA IP CREATION CO., LTD., DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Takeshi Kawauchi, Yukihiro Matsuda
  • Patent number: 8481239
    Abstract: A carrier, including a magnetic particulate core material and a resin layer on the core material, wherein the resin layer includes a resin obtained by heat treatment of a copolymer including a site derived from a monomer component having the following formula (1) and a site derived from a monomer component having the following formula (2), and includes a cross-linked material obtained by hydrolysis of the copolymer to produce a silanol group and condensation using an organotitanium compound: wherein R1 represents a hydrogen atom or a methyl group; m represents an alkylene group having 1 to 8 carbon atoms; R2 represents an alkyl group having 1 to 4 carbon atoms; R3 represents an alkyl group having 1 to 8 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms; X represents 10 to 90 mol %; and Y represents 10 to 90 mol %.
    Type: Grant
    Filed: October 1, 2010
    Date of Patent: July 9, 2013
    Assignee: Ricoh Company Limited
    Inventors: Hisashi Nakajima, Kimitoshi Yamaguchi, Minoru Masuda, Yutaka Takahashi, Koichi Sakata, Hitoshi Iwatsuki, Saori Yamada, Toyoaki Tano
  • Patent number: 8475988
    Abstract: 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: Grant
    Filed: February 2, 2011
    Date of Patent: July 2, 2013
    Assignee: Powdertech Co., Ltd.
    Inventors: Takao Sugiura, Takashi Hikichi, Hiromichi Kobayashi
  • Patent number: 8475989
    Abstract: The carrier is used for a two-component developer for developing an electrostatic latent image, and includes a particulate magnetic core material; and a cover layer located on a surface of the core material and including a crosslinked material and barium sulfate. The cover layer is formed by applying a coating medium including barium sulfate, a copolymer including a unit (A) having a specific acrylic siloxane structure including a tris(trialkylsiloxy)silanyl group and a unit (B) having a specific acrylic silicone structure having a crosslinking ability, and a condensation reaction catalyst, heating the applied medium to a temperature of from 100° C. to 230° C. so that the copolymer is hydrolyzed to produce a material having a silanol group, and the material and the catalyst are subjected to a condensation reaction to form the crosslinked material.
    Type: Grant
    Filed: October 4, 2010
    Date of Patent: July 2, 2013
    Assignee: Ricoh Company, Limited
    Inventors: Yutaka Takahashi, Minoru Masuda, Kimitoshi Yamaguchi, Hisashi Nakajima, Koichi Sakata, Hitoshi Iwatsuki, Saori Yamada, Toyoaki Tano, Mariko Takii
  • Patent number: 8470507
    Abstract: A hybrid developing carrier, comprising a resin layer formed on an outermost surface, wherein the surface of said resin layer is provided with sites formed of an inorganic compound having basic points or acidic points and sites where the resin forming the resin layer is exposed, a hybrid developing device equipped with the hybrid developing carrier, and an image-forming apparatus equipped with the hybrid developing device.
    Type: Grant
    Filed: December 15, 2008
    Date of Patent: June 25, 2013
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventor: Noboru Ito
  • Patent number: 8465898
    Abstract: 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: Grant
    Filed: June 16, 2011
    Date of Patent: June 18, 2013
    Assignee: Powdertech Co., Ltd.
    Inventors: Toru Iwata, Koji Aga
  • Patent number: 8445169
    Abstract: A toner for hybrid development, comprising toner particles containing at least a binder resin and a colorant and being charged when made in friction-contact with a carrier; reverse polarity particles that are charged to polarity reversed to the charged polarity of the toner particles when made in friction-contact with the carrier, and have a number-average primary particle size in a range from 95 to 850 nm; and same polarity particles that are charged into the same polarity as the charged polarity of the toner particles when made in friction-contact with the carrier, and have a number-average primary particle size in a range from 80 to 800 nm and a shape factor in a range from 100 to 160; a developer for hybrid development containing the above toner and a carrier; and an image-forming apparatus provided with the developer for hybrid development.
    Type: Grant
    Filed: June 3, 2009
    Date of Patent: May 21, 2013
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventor: Chikara Tsutsui
  • Patent number: 8435712
    Abstract: The use of electrographic printing to prepare prints which have a desired tactile feel or raised information in a controlled manner by utilizing a developer having toner particle size larger than 50 microns volume average diameter and carrier particles larger than the toner particle size such that the volume average distribution overlap between the toner distribution curve and carrier particle distribution curve is less than 35% and the carrier and toner particles have a volume average diameter size differential equal to or greater than 5 microns or the ratio of carrier-to-toner volume average diameter exceeds 1.25.
    Type: Grant
    Filed: May 21, 2008
    Date of Patent: May 7, 2013
    Assignee: Eastman Kodak Company
    Inventors: Dinesh Tyagi, Patrick M. Lambert, Mark C. Zaretsky, Thomas N. Tombs
  • Patent number: 8431312
    Abstract: 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: Grant
    Filed: November 10, 2009
    Date of Patent: April 30, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Minoru Masuda, Kimitoshi Yamaguchi, Yutaka Takahashi, Koichi Sakata, Hitoshi Iwatsuki
  • Patent number: 8420285
    Abstract: A coated carrier regenerating method in accordance with the present invention includes the step of: determining an amount of a worn-away coating resin of a used coated carrier. Accordingly, an amount of the coating resin layer to be supplemented, namely an amount of the coating resin with which the coating resin layer is to be supplementarily coated is found based on this amount of the worn-away coating resin, whereby the supplementary coating of the used coated carrier can be carried out with the coating resin in the amount thus determined. This allows regeneration of a coated carrier in which a coating resin has a uniform thickness, that is, a coating resin layer has a thickness which is unchanged from the thickness obtained before use of the coated carrier, without the need of completely removing the coating resin from the used coated carrier.
    Type: Grant
    Filed: June 23, 2010
    Date of Patent: April 16, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Takeshi Kato
  • Patent number: 8419977
    Abstract: A conductive coating is described, suitable for coating a developer, charge or transfer roller in a developing apparatus to give a charge providing layer. The coating comprises a conductive polymer in a matrix. A roller is also described, suitable for a developing apparatus comprising, from the center to the periphery, a conductive mandrel, a conductive elastic base layer and a charge providing layer.
    Type: Grant
    Filed: April 15, 2009
    Date of Patent: April 16, 2013
    Assignee: Ten Cate Enbi International B.V
    Inventors: John Jansen, Tsuyoshi Tokiwa, Eiji Sawa
  • Publication number: 20130084521
    Abstract: The carrier core particles for electrophotographic developer include a core composition expressed by a general formula Fe3O4 as a main ingredient and 30 ppm to 400 ppm Na. Such carrier core particles can reduce environmental dependency thereof, while optimizing the resistivity.
    Type: Application
    Filed: May 17, 2011
    Publication date: April 4, 2013
    Applicants: DOWA IP CREATION CO., LTD., DOWA ELECTRONICS MSTERIALS CO., LTD
    Inventor: Takeshi Kawauchi
  • Patent number: 8409778
    Abstract: 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: Grant
    Filed: January 21, 2010
    Date of Patent: April 2, 2013
    Assignees: Sharp Kabushiki Kaisha, Kanto Denka Kogyo Co., Ltd.
    Inventors: Osamu Wada, Tadashi Iwamatsu, Takanori Kamoto, Nobuyuki Yoshioka, Natsuki Matsuura, Nobuhiro Seki, Masatomo Hayashi
  • Patent number: 8399171
    Abstract: A manufacturing apparatus provided with a rotary stirring section and a powder passage is used to manufacture the resin-layer coated carrier. At a fine resin particle adhering step, a magnetic base particle and a fine resin particle are inputted into the powder passage with the rotary stirring section rotating and the fine resin particle is adhered onto the surface of the magnetic base particle. At a spraying step, at least a liquid that plasticizes the fine resin particles is sprayed with spray gas from a spraying section on the magnetic base particle and the fine resin particle which are in a fluidized state in the powder passage. At a film-forming step, rotation by the rotary stirring section is continued to fluidize the magnetic base particles and the fine resin particles until the fine resin particles adhered to the magnetic base particles are softened to form a film.
    Type: Grant
    Filed: June 2, 2010
    Date of Patent: March 19, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takashi Hara, Yoshiaki Akazawa, Yoshitaka Kawase, Yoritaka Tsubaki, Yoshinori Mutoh, Keiichi Kikawa
  • Publication number: 20130011780
    Abstract: 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: Application
    Filed: March 29, 2011
    Publication date: January 10, 2013
    Applicants: DOWA IP CREATION CO., LTD., DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Takeshi Kawauchi, Sho Ogawa
  • Patent number: 8338067
    Abstract: 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: Grant
    Filed: March 26, 2010
    Date of Patent: December 25, 2012
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Susumu Yoshino, Hideo Maehata, Satoshi Hiraoka
  • Publication number: 20120322004
    Abstract: 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: Application
    Filed: October 27, 2011
    Publication date: December 20, 2012
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Takeshi SHOJI, Toshiaki HASEGAWA
  • Publication number: 20120295195
    Abstract: 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: Application
    Filed: January 25, 2011
    Publication date: November 22, 2012
    Applicants: Dowa IP Creation Co., Ltd., Dowa Electronics Materials Co., Ltd.
    Inventor: Takeshi Kawauchi
  • Patent number: 8309293
    Abstract: 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: Grant
    Filed: September 21, 2009
    Date of Patent: November 13, 2012
    Assignee: Xerox Corporation
    Inventors: Daryl W. Vanbesien, Michael S. Hawkins, Corey L. Tracy, Richard P. N. Veregin, Karen Ann Moffat, Biby Esther Abraham
  • Patent number: 8293446
    Abstract: A resin-coated carrier is provided. A resin-coated carrier includes a carrier core and a resin coating layer formed on a surface of the carrier core. The carrier core is composed of a porous material having surface fine pores formed on a surface thereof, and has an apparent density of 1.6 to 2.0 g/cm3. The resin coating layer contains cross-linked fine resin particles. Additionally, the resin-coated carrier is configured such that a volume average particle size of the cross-linked fine resin particles contained in the resin coating layer and an area average diameter of the surface fine pores satisfy a predetermined relational expression.
    Type: Grant
    Filed: April 28, 2010
    Date of Patent: October 23, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Osamu Wada, Takanori Kamoto, Nobuyuki Yoshioka, Ayae Nagaoka, Tadashi Iwamatsu
  • Patent number: 8263302
    Abstract: A carrier for electrophotographic developer, including a core material; and a layer comprising a binder resin, located overlying the core material, wherein the binder resin includes a segment including one or more polymerizable vinyl monomers as a structural unit; and another segment including a partial cleavage structure of polyhedral oligomeric silsesquioxane and/or another partial cleavage structure of polyhedral oligomeric silsesquioxane as a structural unit.
    Type: Grant
    Filed: September 8, 2009
    Date of Patent: September 11, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshihiro Moriya, Akihiro Kotsugai, Toyoshi Sawada, Ryota Inoue, Akiyoshi Sabu, Shingo Sakashita
  • Patent number: 8257896
    Abstract: A carrier which is capable of avoiding excess blocking of the carrier particles at the time of forming a covering layer and is excellent in durability, a developer containing the carrier, and a developer container containing the developer, as well as an image forming method and a process cartridge which use the developer are provided. A carrier including at least a core material particle and a covering layer, a surface of the core material particle being covered with the covering layer, wherein the covering layer contains a condensate which is obtained by condensation of a silicone resin having at least one of a silanol group and a functional group which can be converted to the silanol group by hydrolysis, using a titanium diisopropoxy bis(ethylaceto-acetate) catalyst.
    Type: Grant
    Filed: March 10, 2010
    Date of Patent: September 4, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Minoru Masuda, Kimitoshi Yamaguchi, Yutaka Takahashi, Koichi Sakata, Hitoshi Iwatsuki, Toyoaki Tano
  • Publication number: 20120208121
    Abstract: A carrier core material for electrophotographic developer containing a soft ferrite, expressed by (MgXMn1-x)Fe2O4 (wherein X is in a range of 0.1?X<1.), wherein an analysis value of P on the surface of the carrier core material is 0.1 mass % or more, an analysis value of Mg is 2 mass % or more, a content of Mg in the carrier core material is 2 mass % or more by EDS, and when the content of Mg in the carrier core material is expressed by M1, and the analysis value of Mg on the surface of the carrier core material by EDS is expressed by M2, a value of M2/M1 exceeds 1.0.
    Type: Application
    Filed: June 28, 2010
    Publication date: August 16, 2012
    Applicants: DOWA IP CREATION CO., LTD., DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Masahiro Nakamura, Takeshi Kawauchi, Toshiya Kitamura
  • Patent number: 8213833
    Abstract: An image forming apparatus including at least an image bearer; a charger charging the image bearer; an irradiator irradiating the image bearer to form an electrostatic latent image thereon; an image developer developing the electrostatic latent image with a developer comprising a toner and a carrier to form a toner image on the image bearer; a developer feeder feeding a supplemental developer including the toner and the carrier into the image developer; and a developer collector collecting the developer in the image developer, wherein the developer feeder includes a cylindrical supplemental developer container containing the supplemental developer, including a spiral developer guide race on the inner circumferential surface thereof; and a sub-hopper configured to store the supplemental developer, and wherein the carrier includes a core material; and a layer coated on the core material, including a binder resin and non-black or a non-color inorganic particulate material.
    Type: Grant
    Filed: January 11, 2008
    Date of Patent: July 3, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinichiro Yagi, Tomio Kondou, Masashi Nagayama, Hltoahi Iwatsuki
  • Patent number: 8211610
    Abstract: The carrier includes a particulate core material having magnetism; and a resin layer located on the surface of the particulate core material. The resin layer is prepared by forming a layer including a copolymer, which includes a unit (A) having a specific acrylic siloxane structure, a unit (B) having a specific acrylic silicone structure having a crosslinking ability, and a unit (C) having a specific acrylic structure in a specific ratio, on the particulate core material, and then subjecting the layer to a heat treatment to crosslink the layer.
    Type: Grant
    Filed: March 1, 2010
    Date of Patent: July 3, 2012
    Assignee: Ricoh Company Limited
    Inventors: Kimitoshi Yamaguchi, Minoru Masuda, Yutaka Takahashi, Koichi Sakata, Hitoshi Iwatsuki, Toyoaki Tano
  • Patent number: 8192908
    Abstract: A carrier of the present invention is used in a developer including a toner which includes at least a binder resin and an organic colorant, and the carrier has a core and a coating formed on the surface of the core, the coating including (i) a charge control agent for controlling a charge whose polarity is the same as a polarity of a charge controlled by a charge control agent included in the toner, and (ii) a conductive particles. The use of the carrier of the present invention enables: prevention of decrease in the charging amount of the toner which includes at least a binder resin and an organic colorant; and formation of a stable, high-resolution, high-quality image which has very few image defects such as a photographic fog.
    Type: Grant
    Filed: May 28, 2008
    Date of Patent: June 5, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takanori Kamoto, Tadashi Iwamatsu, Nobuyuki Yoshioka, Yoshinori Mutoh, Hiroyuki Hirakawa, Takashi Hara
  • Patent number: 8163452
    Abstract: A developing agent includes a carrier; a toner in which an inorganic oxide external additive has a coverage of from 60 to 120% relative to a core toner; and a charging auxiliary particle having charge properties of a positive electrode and having a volume average particle size of from 5 to 15 ?m in an addition amount of from 0.5 to 6% by weight relative to the developing agent.
    Type: Grant
    Filed: October 21, 2008
    Date of Patent: April 24, 2012
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventor: Yosuke Imamura
  • Patent number: 8153342
    Abstract: A developer including a toner and a carrier, wherein the carrier is a ferrite carrier coated with a silicone resin and the following relationships are satisfied: log(?Q(t)/Q?)=?kobt ?Q(t)=Q??Q(t) ?2.5 ?log(kob)??1 wherein Q(t) is a charge quantity (?C/g) of the developer after t sec which is a stirring time of the toner and the carrier; Q? is a saturated charge quantity (?C/g) of the developer; and kob is a chargeable speed of the developer.
    Type: Grant
    Filed: September 17, 2007
    Date of Patent: April 10, 2012
    Assignee: Ricoh Company, Ltd.
    Inventor: Akira Izutani
  • Patent number: 8142972
    Abstract: Provided is a developer for replenishment capable of forming a high-quality image even upon duration. The developer for replenishment includes at least a toner and a magnetic carrier, and in the developer for replenishment, 1 part by mass of the magnetic carrier is blended with 2 to 50 parts by mass of the toner, and the magnetic carrier contains a ferrite core and a resin component, has a true specific gravity of 2.5 to 4.2 g/cm3, has a 50% particle diameter on a volume basis (D50) of 15 to 70 ?m, and has an average circularity of 0.850 to 0.950, the average circularity having a coefficient of variation of 1.0 to 10.0%.
    Type: Grant
    Filed: December 5, 2006
    Date of Patent: March 27, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yojiro Hotta, Kazuo Terauchi, Kunihiko Nakamura, Hiroyuki Fujikawa, Yoshinobu Baba, Takayuki Itakura, Hirohide Tanikawa
  • Publication number: 20120064451
    Abstract: A carrier comprising a magnetic core particle having a shape factor SF-2 of 130 to 160 and a resin layer covering a surface of the magnetic core particle. The resin layer comprises a conductive particle and a resin obtained by heating a copolymer comprising a silicon-containing A unit and another silicon-containing B unit having.
    Type: Application
    Filed: September 6, 2011
    Publication date: March 15, 2012
    Inventors: Hiroyuki Kishida, Shigenori Yaguchi, Kimitoshi Yamaguchi, Toyoshi Sawada, Hiroshi Tohmatsu, Koichi Sakata, Hitoshi Iwatsuki, Toyoaki Tano, Mariko Takii
  • Patent number: 8101330
    Abstract: A two component developer comprising a toner and a carrier, wherein the toner includes: colored particles; and external additive particles comprising a complex oxide incorporating silicon atoms and at least one of titanium atoms and aluminum atoms, and a surface existing ratio of the silicon atoms (R2) in a surface of the external additive particles being larger than an average existing ratio of the silicon atoms (R1) in an entirety of the external additive particles, and carrier particles comprise magnetic material powder dispersed in a phenol-formaldehyde resin, and have an average of the shape coefficient SF-1 of 1.0 to 12 and an average of the shape coefficient SF-2 of 1.1 to 2.5, and a volume based median diameter of from 10 to 100 ?m.
    Type: Grant
    Filed: March 4, 2009
    Date of Patent: January 24, 2012
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Masahiro Anno, Masahiko Nakamura, Tsuyoshi Uchida, Kenichi Onaka, Junya Onishi, Naoya Tonegawa
  • Publication number: 20120015291
    Abstract: An electrostatic image developing carrier includes a core particle and a coating layer on the core particle. The coating layer contains a resin having a crosslinked structure formed by using at least one compound selected from boric acid and boric acid derivatives.
    Type: Application
    Filed: March 14, 2011
    Publication date: January 19, 2012
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Susumu YOSHINO, Sumiaki YAMASAKI, Satoshi HIRAOKA, Shigeru SEITOKU, Hirofumi SHIOZAKI, Kazuhiko YANAGIDA
  • Patent number: 8092965
    Abstract: Provided is a method for forming an image containing the steps of: (a) forming an electrostatic latent image on an electrostatic latent image carrier; and (b) developing the electrostatic latent image by a two component developer comprising a toner and a carrier, wherein the two component developer is continually replenished in the developing step (b); and the toner includes: colored particles; and external additive particles comprising a complex oxide incorporating silicon atoms and at least one of titanium atoms and aluminum atoms, and a surface existing ratio of the silicon atoms (R2) in a surface of the external additive particles being larger than an average existing ratio of the silicon atoms (R1) in an entirety of the external additive particles.
    Type: Grant
    Filed: February 17, 2009
    Date of Patent: January 10, 2012
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Masahiro Anno, Masahiko Nakamura, Tsuyoshi Uchida, Kenichi Onaka, Junya Onishi, Naoya Tonegawa
  • Patent number: 8062822
    Abstract: An electrostatic latent image developing carrier is provided which comprises a core particle and a resin coating layer containing conductive particles dispersed therein, the carrier having a volume average particle diameter of 25 to 60 ?m and an average degree of circularity of 0.975 or more, wherein the core particle has a BET specific surface area of 0.1 to 0.3 m2/g and an internal void ratio of 10% or less.
    Type: Grant
    Filed: December 7, 2005
    Date of Patent: November 22, 2011
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Satoshi Inoue, Masahiro Takagi, Koutarou Yoshihara
  • Patent number: 8039183
    Abstract: A pigment particle coated with at least one of a resin and a charge control surface additive, wherein the pigment particle is a pearlescent or metallic pigment. The pigment adds pearlescent effects and is of a size and charge as to be used as a toner material in electrostatographic or xerographic image formation.
    Type: Grant
    Filed: October 25, 2007
    Date of Patent: October 18, 2011
    Assignee: Xerox Corporation
    Inventors: Richard P. N. Veregin, Karen A. Moffat, Michael S. Hawkins, Cuong Vong, Eric M. Strohm, Wafa Faisul Bashir, Shigang Qiu
  • Publication number: 20110244389
    Abstract: Disclosed are a ferrite carrier core material for an electrophotographic developer including a ferrite particle having an apparent density of 2.30 to 2.80 g/cm3, a BET specific surface area of 0.09 to 0.70 m2/g and an average degree of circularity of 0.90 or more, wherein the Cl concentration of the ferrite carrier core material measured by an elution method is 0.1 to 100 ppm, a ferrite carrier for an electrophotographic developer obtained by coating the surface of the ferrite carrier core material with a resin, and methods for producing the ferrite carrier core material and the ferrite carrier, and an electrophotographic developer using the ferrite carrier.
    Type: Application
    Filed: March 25, 2011
    Publication date: October 6, 2011
    Applicant: POWDERTECH CO., LTD.
    Inventors: Takashi KOJIMA, Tetsuya UEMURA
  • Publication number: 20110244388
    Abstract: There is provided a resin-coated carrier for an electrophotographic developer, including: a carrier core particle; and a coating resin layer comprising a silicone resin or a modified silicone resin formed on a surface of the carrier core particle, wherein a titanium-ethyl acetoacetate chelate or a titanium-octylene glycol chelate is contained in the coating resin layer as a titanium chelate, and wherein the content of the titanium-ethyl acetoacetate chelate or the titanium-octylene glycol chelate is 5.0 to 50.0% by weight based on coating resin solids. There is also provided an electrophotographic developer using the resin-coated carrier.
    Type: Application
    Filed: March 25, 2011
    Publication date: October 6, 2011
    Applicant: POWDERTECH CO., LTD.
    Inventors: Tetsuya UEMURA, Tomoaki KOBAYASHI, Masashi AOKI
  • Publication number: 20110236812
    Abstract: An electrostatic latent image developing toner includes a mother particle which contains a coloring agent, a release agent and a binder resin; and an inorganic particle which is added to the surface of the mother particle, and wherein a relation between a relaxation time t and a relaxation modulus G(t) which are determined from the dynamic viscoelasticity measurement made on the toner satisfies the following equations (1) and (2); G(t1)<100 Pa??(1) 515<(G(t2)?G(t1))/(log(t1)?log(t2))<1,230??(2) wherein t1 represents the maximum relaxation time and t2 represents the minimum relaxation time.
    Type: Application
    Filed: August 17, 2010
    Publication date: September 29, 2011
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Yuka ISHIHARA, Masaki NAKAMURA, Satoshi INOUE, Katsumi DAIMON
  • Patent number: 8026032
    Abstract: A carrier for use in an image forming apparatus in which a toner and a carrier are fed to an image developer thereof and an extra developer including the toner and the carrier in the image developer is discharged therefrom, wherein at least one of the carrier fed to the image developer and a carrier readily contained therein includes a core material; and a coated film coating the core material, and wherein the coated film includes a binder resin and a particulate material having a ratio of an average particle diameter thereof to an average thickness of the coated film of from 0.01 to 1, and includes concavities and convexities having an average difference of elevation of from 0.02 to 3.0 ?m.
    Type: Grant
    Filed: October 11, 2007
    Date of Patent: September 27, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Hitoshi Iwatsuki, Tomio Kondou, Shinichiro Yagi, Masashi Nagayama
  • Publication number: 20110217643
    Abstract: A carrier for electrostatic image development includes: a carrier body including a core and a resin coating layer on the core; and first spherical silica particles having a volume-average particle diameter of from 50 nm to 300 nm that adhere to the surface of the carrier body at a ratio of from 0.001 parts by weight to 0.100 parts by weight relative to 100 parts by weight of the carrier body.
    Type: Application
    Filed: August 12, 2010
    Publication date: September 8, 2011
    Applicant: FUJI XEROX CO., LTD.
    Inventor: Daisuke ISHIZUKA
  • Publication number: 20110217649
    Abstract: 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 cone 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: Application
    Filed: November 10, 2009
    Publication date: September 8, 2011
    Inventors: Minoru Masuda, Kimitoshi Yamaguchi, Yutaka Takahashi, Koichi Sakata, Hitoshi Iwatsuki