Chemically Or Physically Identified Binder Or Coating Resin For Magnetic Carrier Patents (Class 430/111.35)
  • 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
  • Publication number: 20120251942
    Abstract: There are provided a resin-coated carrier for an electrophotographic developer, in which a magnetic particle is coated with a resin on its surface, and the coating resin contains a carbon nanotube having a carbon content of 75% by weight or more, and an electrophotographic developer using the resin-coated carrier.
    Type: Application
    Filed: March 28, 2012
    Publication date: October 4, 2012
    Applicant: POWDERTECH CO., LTD.
    Inventors: Tetsuya UEMURA, Makoto ISHIKAWA
  • 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: 20120214097
    Abstract: Provided are a magnetic carrier and a two-component developer comprising the magnetic carrier. The magnetic carrier comprises magnetic carrier particles, each of which comprises a magnetic carrier core, the surface of which is coated with a charge control agent and further coated with a resin coat layer containing a resin composition.
    Type: Application
    Filed: August 24, 2011
    Publication date: August 23, 2012
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Takeshi Naka, Yoshinobu Baba, Koh Ishigami
  • Publication number: 20120214098
    Abstract: A carrier for a two-component developer, includes: magnetic particles and a resin coating layer that is coated on the magnetic particles, the resin coating layer containing metal nitride particles having a volume average primary particle diameter of from about 300 to about 2,000 nm.
    Type: Application
    Filed: September 2, 2011
    Publication date: August 23, 2012
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Norihito FUKUSHIMA, Toshiaki HASEGAWA, Yosuke TSURUMI
  • Patent number: 8247150
    Abstract: A carrier for developing an electrostatic latent image which includes a core material and a resin coating layer provided on the core material. The resin coating layer includes a resin and a particulate tin oxide, and the surface of the particulate tin oxide is coated with carbon.
    Type: Grant
    Filed: September 17, 2009
    Date of Patent: August 21, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Hitoshi Iwatsuki, Kimitoshi Yamaguchi, Minoru Masuda, Yutaka Takahashi, Koichi Sakata
  • Patent number: 8247149
    Abstract: To provide an electrophotographic developer carrier including a carrier core material, and a coat layer containing a binder resin and conductivity-imparted microparticles which are produced by imparting conductivity to inorganic microparticles, the coat layer being formed over the carrier core material, wherein the electrophotographic developer carrier has a static resistivity of 10 [Log (?·cm)] or higher and a dynamic resistivity of 9 [Log (?)] or lower, and is used in an electrophotographic developer together with a negatively chargeable toner having an average circularity of 0.925 to 0.970, and wherein the toner includes a resin, a colorant and an inorganic layered mineral in which at least part of interlayer ions is modified with organic ions, and is granulated by dispersing and/or emulsifying an oil phase and/or a monomer phase containing at least a toner composition and/or a toner composition precursor in an aqueous medium.
    Type: Grant
    Filed: December 2, 2008
    Date of Patent: August 21, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinichiro Yagi, Kousuke Suzuki, Masashi Nagayama
  • Publication number: 20120202147
    Abstract: An anisotropic magnetic material-dispersed resin carrier including: fine magnetic particles; and a binder resin in which at least the fine magnetic particles are dispersed, wherein the anisotropic magnetic material-dispersed resin carrier has a magnetic anisotropy where magnetic fields of the fine magnetic particles are orientated in the same direction, and wherein the anisotropic magnetic material-dispersed resin carrier has a saturation magnetization of 16 emu/g to 30 emu/g, a coercive force of 15 kA/m to 40 kA/m, and a number average particle diameter of 15 ?m or more but less than 100 ?m.
    Type: Application
    Filed: January 31, 2012
    Publication date: August 9, 2012
    Applicant: RICOH COMPANY, LTD.
    Inventors: Kazumi SUZUKI, Masaki Yoshino, Hisao Kurosu, Tatsuya Morita, Tomoko Kino, Shingo Sakashita
  • Patent number: 8227163
    Abstract: The present disclosure provides carriers for use with toner compositions. In embodiments, a carrier may include a core having a polymeric coating on at least a portion thereof. The polymer coating possesses cation binding groups. Processes for coating such carriers with the polymeric coatings are also provided.
    Type: Grant
    Filed: March 23, 2010
    Date of Patent: July 24, 2012
    Assignee: Xerox Corporation
    Inventors: Richard P. N. Veregin, Daryl W. Vanbesien, Michael S. Hawkins, Corey L. Tracy
  • Patent number: 8216759
    Abstract: The present invention provides an electrophotographic carrier which includes a core particle, a first resin layer containing a charge-generating material for coating the core particle, and a second resin layer containing a hole-transporting material for coating the first resin layer. The invention also provides a two-component developer comprising said carrier, and an image-forming process and apparatus using said developer. According to the invention, high quality images can be formed, with excellent image density (especially when developing solid images) and less fogging.
    Type: Grant
    Filed: June 23, 2009
    Date of Patent: July 10, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Keigo Mitamura
  • 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: 8187781
    Abstract: Employed are a resin-filled ferrite carrier for an electrophotographic developer filled with a resin in voids of a porous ferrite core material, wherein the resin filled in the voids is a silicone resin which has a softening point of 40° C. or above and is cured at or above such softening point, and the filled amount is 7 to 30 parts by weight based on 100 parts by weight of the core material, a method for producing thereof band an electrophotographic developer using this ferrite carrier.
    Type: Grant
    Filed: March 4, 2008
    Date of Patent: May 29, 2012
    Assignee: Powdertech Co., Ltd.
    Inventors: Hiromichi Kobayashi, Takao Sugiura
  • Publication number: 20120129087
    Abstract: The present invention relates to a magnetic carrier for an electrophotographic developer comprising spherical magnetic composite particles comprising a phenol resin as a binder and ferromagnetic iron oxide particles bonded to each other through the phenol resin, wherein the spherical magnetic composite particles have a ten-point mean roughness Rz of 0.3 to 2.0 ?m. The magnetic carrier for an electrophotographic developer according to the present invention exhibits an excellent durability against peeling-off and abrasion of coating resins formed thereon and a high stability to mechanical stress exerted onto the carrier, is free from occurrence of spent toner, can be stably held over a long period of time without occurrence of fogging and unevenness in density of toner images, and can keep high-quality images with an excellent gradation for a long period of time.
    Type: Application
    Filed: June 4, 2010
    Publication date: May 24, 2012
    Inventors: Katsuji Iwami, Shigenori Harada, Eiichi Kurita, Kaori Kinoshita
  • Publication number: 20120122028
    Abstract: A carrier for developing an electrostatic image, includes: magnetic core material particles and a coated layer coated on the magnetic core material particles, the coated layer containing a resin having a monomer unit represented by formula (A): wherein R1 represents a hydrogen atom or a methyl group; R2 to R4 each independently represent a hydrogen atom, an alkyl group, an aryl group or an aralkyl group; R5 independently represents an alkyl group, an aryl group or an aralkyl group; n represents an integer of from 0 to 7; and L1 represents a single bond or an alkylene group, provided that at least one of R3 and R4 is not a hydrogen atom.
    Type: Application
    Filed: April 21, 2011
    Publication date: May 17, 2012
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Yasuaki HASHIMOTO, Yosuke TSURUMI
  • Patent number: 8178273
    Abstract: To provide (1) a method for manufacturing a carrier, including: dissolving a coating material composed of a plurality of types of materials in a fluid containing at least one of a supercritical fluid and a subcritical fluid; and lowering the solubility of the solution by controlling at least one of pressure and temperature to form a coating layer on a core surface, or (2) a method for manufacturing a carrier, including: dispersing or dissolving a coating material in a fluid containing at least one of a supercritical fluid and a subcritical fluid; and lowering solubility of the solution by controlling at least one of pressure and temperature to form a coating layer on a core surface, wherein the coating material contains at least a silicone resin, and the silicone resin has a weight-average molecular weight (Mw) of 800 to 5,000.
    Type: Grant
    Filed: September 11, 2007
    Date of Patent: May 15, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Ryota Inoue, Chiaki Tanaka, Shinichi Kuramoto
  • Publication number: 20120115078
    Abstract: 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: Application
    Filed: June 15, 2010
    Publication date: May 10, 2012
    Inventors: Kaori Kinoshita, Shinji Uemoto, Eiichi Kurita
  • Patent number: 8142971
    Abstract: An electrostatic charge developer includes a carrier having a core material and a resin coating layer covering the surface of the core material, and a toner having a binder resin that contains a non-crystalline polyester resin and a crystalline polyester resin. The resin coating layer contains a copolymer that contains a nitrogen-containing acrylic ester or nitrogen-containing methacrylic ester and an alicyclic acrylic ester or alicyclic methacrylic ester. The non-crystalline polyester resin contains at least an alkyl succinic acid or an anhydride or lower alkyl ester thereof, or an alkenyl succinic acid or an anhydride or lower alkyl ester thereof. The crystalline polyester resin is an aliphatic polyester resin.
    Type: Grant
    Filed: October 14, 2008
    Date of Patent: March 27, 2012
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Noriyuki Mizutani, Yasuhiro Arima, Fusako Kiyono, Susumu Yoshino
  • Publication number: 20120052435
    Abstract: A tin-zinc complex oxide powder includes particles containing a tin-zinc complex oxide and having a volume resistivity of about 1×105 ?·cm or less.
    Type: Application
    Filed: May 17, 2011
    Publication date: March 1, 2012
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Kazunori ANAZAWA, Tomoko MIYAHARA, Kaoru TORIKOSHI
  • Patent number: 8114562
    Abstract: A two-component developer containing a yellow toner and a magnetic carrier, wherein the yellow toner has the characteristics: (i) when the concentration of the yellow toner in a solution of the yellow toner in chloroform is represented by Cy (mg/ml) and the absorbance of the solution at a wavelength of 422 nm is represented by A422, a relationship between Cy and A422 satisfies the relationship of 6.00<A422/Cy<14.40; (ii) the lightness L* and chroma C* of the yellow toner determined in a powder state satisfy the relationships of 85.0?L*?95.0 and 100.0?C*?115.0; and (iii) the absolute value for the triboelectric charge quantity of the yellow toner measured by a two-component method using the yellow toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.
    Type: Grant
    Filed: March 3, 2010
    Date of Patent: February 14, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Koh Ishigami, Kazuo Terauchi, Noriyoshi Umeda, Tetsuya Ida, Naoki Okamoto, Yojiro Hotta, Yoshinobu Baba, Takayuki Itakura, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo
  • Patent number: 8067136
    Abstract: To provide: a charge control agent having negative chargeability, which contributes to environmental conservation and the like to an increased degree, has high performance (high charge amount, quick rise-up of charge, excellent stability with time, and high environmental stability), and has improved dispersibility; a toner for developing an electrostatic charge image containing the charge control agent; and an image forming method and an image forming apparatus each using the toner for developing an electrostatic charge image. A charge control agent for controlling a charged state of powder, characterized by including one or more units each represented by the following chemical formula (1) in a molecule.
    Type: Grant
    Filed: June 9, 2005
    Date of Patent: November 29, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tetsuya Yano, Takashi Kenmoku, Tatsuki Fukui, Ako Kusakari, Chieko Mihara
  • 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: 8053073
    Abstract: A process for producing resin-coated metal particles includes coating surfaces of metal particles with silica; allowing a polymerizable group to adsorb onto the surfaces of the silica-coated particles by the use of a silane coupling agent; and coating the surfaces of the silica-coated particles with a polymeric resin by mixing the particles to which the polymerizable groups have been adsorbed, a polymerizable monomer, a polymerization initiator, and a dispersant to polymerize the polymerizable monomer and the polymerizable groups.
    Type: Grant
    Filed: September 15, 2004
    Date of Patent: November 8, 2011
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Kiyoko Ueda, Ichiro Nakamura, Kiyoyasu Sakurada
  • Patent number: 8043785
    Abstract: The present invention provides a method for producing a carrier that includes dissolving at least a coating material in carbon dioxide in a liquid state, and forming a coating layer on a core material surface by reducing the solubility of the liquid with at least the coating material dissolved therein through control of at least any one of the pressure and temperature. The present invention also provides a carrier produced by the method for producing a carrier.
    Type: Grant
    Filed: November 23, 2007
    Date of Patent: October 25, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Ryota Inoue, Chiaki Tanaka, Masayuki Ishii, Yoshihiro Moriya, Shingo Sakashita
  • Patent number: 8039184
    Abstract: Provided is a two-component developer with which degradation of development is inhibited even in the case of prolonged use, and thereby a high quality image exhibiting high resolution and sufficient image density can be formed for a long duration. Also disclosed is a two-component developer possessing a carrier and a toner, wherein the carrier in which magnetic material powder is dispersed in a binder resin containing a phenol formaldehyde resin has a shape coefficient SF-1 of 1.0-1.2, a shape coefficient SF-2 of 1.1-2.5 and a volume-based median particle diameter of 10-100 ?m, and the toner possesses a colored particle and an external additive particle, wherein the external additive particle comprises a titanic acid compound and iron, and the iron content is 100-1,000 ppm, based on the titanic acid compound.
    Type: Grant
    Filed: March 5, 2009
    Date of Patent: October 18, 2011
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Masahiro Anno, Masahiko Nakamura, Tsuyoshi Uchida, Kenichi Onaka, Junya Onishi, Naoya Tonegawa
  • Patent number: 8039189
    Abstract: The present invention can provide small-diameter core material particles for electro photographic carrier, the particles that can prevent occurrences of carrier adhesions and reduce toner spent, have excellent durability and cause little fluctuations in image density with a narrow particle diameter distribution, and an efficient, cost-effective production method thereof. That is, the core material particles for electro photographic carrier are particles wherein the weight average particle diameter, Dw, is in the range of 22 ?m to 32 ?m, the ratio of Dw to the number average particle diameter, Dp, satisfies the condition, 1<Dw/Dp<1.20, the content of particles smaller than 20 ?m in diameter is in the range of 0% by mass to 7% by mass and smaller than 36 ?m is in the range of 90% by mass to 100% by mass, and the BET specific surface area is in the range of 300 cm2/g to 900 cm2/g.
    Type: Grant
    Filed: April 17, 2007
    Date of Patent: October 18, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Kimitoshi Yamaguchi, Naoki Imahashi, Masashi Nagayama
  • Publication number: 20110236820
    Abstract: An electrostatic charge image development carrier includes magnetic core particles and a resin coating layer that contains titanium dioxide particles doped with niobium and coats each of the magnetic core particles.
    Type: Application
    Filed: August 26, 2010
    Publication date: September 29, 2011
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Toshiaki HASEGAWA, Takeshi SHOJI, Sakon TAKAHASHI, Fusako KIYONO
  • Publication number: 20110236815
    Abstract: The present disclosure provides carriers for use with toner compositions. In embodiments, a carrier may include a core having a polymeric coating on at least a portion thereof. The polymer coating possesses cation binding groups. Processes for coating such carriers with the polymeric coatings are also provided.
    Type: Application
    Filed: March 23, 2010
    Publication date: September 29, 2011
    Applicant: XEROX CORPORATION
    Inventors: Richard P.N. Veregin, Daryl W. Vanbesien, Michael S. Hawkins, Corey L. Tracy
  • 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: 20110229817
    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: Application
    Filed: March 1, 2011
    Publication date: September 22, 2011
    Inventors: Saori YAMADA, Minoru Masuda, Hisashi Nakajima, Kimitoshi Yamaguchi, Koichi Sakata, Hitoshi Iwatsuki, Yutaka Takahashi, Toyoaki Tano, Mariko Takii
  • Patent number: 7981582
    Abstract: A toner having a crystalline or semi-crystalline polyester resin, an amorphous resin and a colorant. The toner preferably exhibits a resistivity of at least 1×1011 ohm-cm. A developer may be produced including the toner and optionally a carrier. If a carrier is included, the carrier preferably exhibits a resistivity of greater than 1×107 ohm-cm. An electrophotographic machine includes the toner exhibiting high resistivity.
    Type: Grant
    Filed: June 23, 2005
    Date of Patent: July 19, 2011
    Assignee: Xerox Corporation
    Inventors: Richard P. N. Veregin, Michael S. Hawkins, Vladislav Skorokhod, Valerie M. Farrugia
  • Patent number: 7964330
    Abstract: There are adopted an electrophotographic resin-coated ferrite carrier having a carrier core coated with a resin, wherein a product of an apparent density ? (g/cm3), average particle size d (?m) and BET specific surface area S (m2/g) of the carrier core satisfies the following condition, a method for producing the same, and an electrophotographic developer. 4.5??×d×S?8.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: June 21, 2011
    Assignee: Powertech Co., Ltd.
    Inventors: Issei Shinmura, Kanao Kayamoto
  • Patent number: 7939233
    Abstract: A magnetic carrier and a two-component developer are provided which have remedied blank areas, fog after leaving, carrier sticking during running, and image density variations before and after running. The magnetic carrier has magnetic carrier particles having at least porous magnetic core particles and a resin. The magnetic carrier particles satisfying the specific conditions (a), (b) and (c) where, in a reflected electron image of cross sections of the magnetic carrier particles as photographed with a scanning electron microscope, straight lines that divide a cross section of a magnetic carrier particle into 72 at intervals of 5° are drawn from a reference point of the cross section thereof toward the surface of the magnetic carrier particle; the magnetic carrier particles being contained in an amount of 60% by number or more.
    Type: Grant
    Filed: January 21, 2010
    Date of Patent: May 10, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Chika Inoue, Hiroyuki Fujikawa, Koh Ishigami, Kunihiko Nakamura, Nozomu Komatsu, Tomoko Endo, Yoshinobu Baba, Takayuki Itakura
  • Patent number: 7939232
    Abstract: A toner or two-component developer is obtained by mixing, aggregating, and heating resin particles, colorant particles, and wax particles in an aqueous medium. A gel permeation chromatography (GPC) measurement of the resin particles shows that a weight-average molecular weight is 10000 to 60000, and the ratio of the weight-average molecular weight to a number-average molecular weight is 1.5 to 6. The wax particles include at least a first wax and a second wax. An endothermic peak temperature (melting point Tmw1 (° C.)) of the first wax based on a DSC method is 50° C. to 90° C. An endothermic peak temperature (melting point Tmw2 (° C.)) of the second wax based on the DSC method is at least 5° C. to 50° C. higher than Tmw1. Thus, the toner can have a smaller particle size and a sharp particle size distribution without requiring a classification process, can achieve a longer life, and can suppress transfer voids or scattering during transfer.
    Type: Grant
    Filed: November 1, 2005
    Date of Patent: May 10, 2011
    Assignee: Panasonic Corporation
    Inventors: Yasuhito Yuasa, Hidekazu Arase, Masahisa Maeda
  • Patent number: 7939234
    Abstract: An image forming apparatus, including a latent image-holding member, a developing unit, a transfer unit, a cleaning unit, and a recycling unit, wherein the developer includes a toner having an external-additive adhesiveness index SA in the range of approximately 50% to approximately 95% and: a carrier containing magnetic particles and a coating layer coating the surface of the magnetic particles and having a total energy of approximately 1,420 to approximately 2,920 mJ; or a carrier containing magnetic powder-dispersed particles and a coating layer coating the surface of the magnetic powder-dispersed particles and having a total energy of, approximately 890 to approximately 1,390 mJ.
    Type: Grant
    Filed: May 30, 2007
    Date of Patent: May 10, 2011
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Akira Matsumoto, Akihiro Iizuka, Fusako Kiyono
  • Publication number: 20110097662
    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. 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: Application
    Filed: October 22, 2009
    Publication date: April 28, 2011
    Applicant: XEROX CORPORATION
    Inventors: Daryl W. Vanbesien, Michael S. Hawkins, Suxia Yang, Richard P.N. Veregin, Karen Ann Moffat
  • Publication number: 20110091802
    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: Application
    Filed: October 4, 2010
    Publication date: April 21, 2011
    Inventors: Yutaka TAKAHASHI, Minoru Masuda, Kimitoshi Yamaguchi, Hisashi Nakajima, Koichi Sakata, Hitoshi Iwatsuki, Saori Yamada, Toyoaki Tano, Mariko Takii
  • Patent number: 7927775
    Abstract: Provided is a magnetic carrier giving a high quality image free of density variation without the occurrence of fogging or carrier adhesion and having excellent dot reproducibility even during long-term use. The magnetic carrier has magnetic carrier particles produced by filling pores of porous magnetic core particles with a resin. The magnetic carrier contains 80% by number or more of the magnetic carrier particles satisfying the specific conditions (a) and (b) when 18 straight lines passing through a reference point of a cross section of the magnetic carrier particle are drawn at intervals of 10° in a reflected electron image of the cross section of the magnetic carrier particle photographed by a scanning electron microscope.
    Type: Grant
    Filed: January 21, 2010
    Date of Patent: April 19, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Nozomu Komatsu, Koh Ishigami, Hiroyuki Fujikawa, Kunihiko Nakamura, Chika Inoue, Yoshinobu Baba, Takayuki Itakura, Tomoko Endo
  • Publication number: 20110086307
    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: Application
    Filed: October 1, 2010
    Publication date: April 14, 2011
    Inventors: Hisashi NAKAJIMA, Kimitoshi Yamaguchi, Minoru Masuda, Yutaka Takahashi, Koichi Sakata, Hitoshi Iwatsuki, Saori Yamada, Toyoaki Tano
  • Patent number: 7914964
    Abstract: An image forming method of forming images on both sides of a recording sheet; comprising the steps of: fixing a first toner image on a first surface a recording sheet; and fixing a second toner image on a second surface of the recording sheet; wherein in two-component developer includes toner particles each containing a binder resin having a glass transition temperature Tg° C. and a colorant and carrier particles in each on which magnetic powder is dispersed in a binder resin including a phenol formaldehyde obtained by a polymerization process, and the first toner image is fixed with first heat in such a way that the surface temperature of the first surface of the recording sheet is a temperature in a range of Tg° C. or more and lower than 100° C.
    Type: Grant
    Filed: July 20, 2007
    Date of Patent: March 29, 2011
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Hiroshi Yamazaki, Ken Ohmura
  • Publication number: 20110070540
    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: Application
    Filed: September 21, 2009
    Publication date: March 24, 2011
    Applicant: XEROX CORPORATION
    Inventors: Daryl W. Vanbesien, Michael S. Hawkins, Corey L. Tracy, Richard P.N. Veregin, Karen Ann Moffat, Biby Esther Abraham
  • Patent number: 7906262
    Abstract: A two-component developer containing a cyan toner and a magnetic carrier, wherein the cyan toner has the characteristics: (i) when the concentration of the cyan toner in a solution of the cyan toner in chloroform is represented by Cc (mg/ml) and the absorbance of the solution at a wavelength of 712 nm is represented by A712, a relationship between Cc and A712 satisfies the relationship of 2.00<A712/Cc<8.15; (ii) the lightness L* and chroma C* of the cyan toner determined in a powder state satisfy the relationships of 25.0?L*?40.0 and 50.0?C*?60.0; and (iii) the absolute value for the triboelectric charge quantity of the cyan toner measured by a two-component method using the cyan toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.
    Type: Grant
    Filed: March 3, 2010
    Date of Patent: March 15, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Koh Ishigami, Kazuo Terauchi, Noriyoshi Umeda, Tetsuya Ida, Naoki Okamoto, Yojiro Hotta, Yoshinobu Baba, Takayuki Itakura, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo
  • Publication number: 20110020747
    Abstract: An electrophotographic carrier includes a magnetic core material and a resin layer that coats the magnetic core material, the resin layer comprising a resistance control agent and a polymer including a repeating unit derived from an alicyclic group-containing methacrylic ester, the resin layer including a monomer as a base material of the repeating unit in the polymer in an amount of from about 0.5% by weight to about 3.0% by weight relative to the total amount of the resin layer.
    Type: Application
    Filed: March 18, 2010
    Publication date: January 27, 2011
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Fusako Kiyono, Takeshi Shoji, Yosuke Tsurumi, Akihiro Iizuka
  • Patent number: 7867683
    Abstract: A toner that when the complex elastic modulus measured at an angular frequency of 6.28 rad/sec., and a strain amount of 0.3% is 1×106 Pa or more and 1×108 Pa or less, the tangent loss is 0.5 or more and 1.8 or less.
    Type: Grant
    Filed: April 20, 2007
    Date of Patent: January 11, 2011
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Masanobu Ninomiya, Toyofumi Inoue, Masataka Kuribayashi, Masashi Ikeda, Takafumi Koide
  • Patent number: 7862977
    Abstract: A method to form an image using a trickle developing system, wherein (a) the toner comprises colorant particles with a volume median diameter of 3 to 8 ?m having first inorganic particles on surfaces of the colorant particles to form toner particles; (b) the carrier comprises magnetic particles with a weight average particle diameter (D4) of 20 to 40 ?m having second inorganic particles on surfaces of the magnetic particles to form carrier particles; and (c) an area ratio of element (A) based on a total area of surfaces of the carrier particles is 0.5 to 3.0 area % determined by using an X-ray analysis, provided that element (A) represents one or more elements commonly contained in the first inorganic particles and in the second inorganic particles.
    Type: Grant
    Filed: April 3, 2007
    Date of Patent: January 4, 2011
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Makoto Kobayashi, Yoshiyasu Matsumoto
  • Patent number: 7858283
    Abstract: A magnetic carrier which has magnetic carrier particles each having at least porous magnetic core particles and a resin, in which, in a backscattered electron image of the magnetic carrier particles, photographed with a scanning electron microscope as taken at an accelerating voltage of 2.0 kV, magnetic carrier particles having area proportion S1 found from a specific expression (1) of from 0.5 area % or more to 8.0 area % or less are in a proportion of 8.0% by number or more in the magnetic carrier, an average proportion Av1 of the total area of portions having a high luminance which come from a metal oxide on the magnetic carrier particles to the total projected area of the magnetic carrier particles is from 0.5 area % or more to 8.0 area % or less, and an average proportion Av2 found from a specific expression (2) is 10.0 area % or less.
    Type: Grant
    Filed: January 21, 2010
    Date of Patent: December 28, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Koh Ishigami, Hiroyuki Fujikawa, Kunihiko Nakamura, Nozomu Komatsu, Chika Inoue, Tomoko Endo, Yoshinobu Baba, Takayuki Itakura
  • Patent number: 7846631
    Abstract: Provided is a toner including toner particles each containing at least a binder resin, a colorant, and a wax component, and an inorganic fine powder, the toner being wherein: in a microscopic compression test on the toner, a recovery ratio Z(25) and the gradient of a load-displacement curve R(25) each satisfy a specific range; and the toner has a glass transition temperature (TgA) measured with a differential scanning calorimeter (DSC) in a specific range and a temperature (P1) of the highest endothermic peak measured with the DSC in a specific range, and the temperature (P1) of the highest endothermic peak and the glass transition temperature (TgA) satisfy a specific relationship.
    Type: Grant
    Filed: January 20, 2009
    Date of Patent: December 7, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasushi Katsuta, Koji Inaba, Ken-ichi Nakayama, Kenta Kamikura
  • Publication number: 20100273103
    Abstract: 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: Application
    Filed: February 26, 2009
    Publication date: October 28, 2010
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Yoshinobu Baba, Koh Ishigami, Naoki Okamoto, Tomoko Endo
  • Publication number: 20100239975
    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: Application
    Filed: March 1, 2010
    Publication date: September 23, 2010
    Inventors: Kimitoshi YAMAGUCHI, Minoru MASUDA, Yutaka TAKAHASHI, Koichi SAKATA, Hitoshi IWATSUKI, Toyoaki TANO