Patents by Inventor Hitoshi Iwatsuki

Hitoshi Iwatsuki has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • 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
  • Publication number: 20110065037
    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: Application
    Filed: September 10, 2010
    Publication date: March 17, 2011
    Inventors: Hitoshi Iwatsuki, Kimitoshi Yamaguchi, Minoru Masuda, Yutaka Takahashi, Koichi Sakata, Toyoaki Tano
  • 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
  • Publication number: 20100233613
    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: Application
    Filed: March 10, 2010
    Publication date: September 16, 2010
    Inventors: Minoru MASUDA, Kimitoshi Yamaguchi, Yutaka Takahashi, Koichi Sakata, Hitoshi Iwatsuki, Toyoaki Tano
  • Patent number: 7745084
    Abstract: A toner including a binder resin and a colorant, wherein a pellet of the toner which is prepared by applying a pressure of 15 kg/cm2 to the toner has a tensile strength of from 900 Pa to 10,000 Pa, and wherein the toner has a methanol wettability of from 25 to 65% by volume, wherein the methanol wettability is measured by a method in which the toner is dispersed in a mixture solvent of water and methanol, and methanol is added to the toner dispersion while checking the transparency of the dispersion to determine a transparency fall starting point, wherein the methanol wettability is defined as {Vm/(Vm+Vw)}×100, wherein Vm represents a total volume (ml) of methanol in the dispersion at the transparency dropping point, and Vw represents the total volume of the pure water added.
    Type: Grant
    Filed: July 21, 2005
    Date of Patent: June 29, 2010
    Assignee: Ricoh Company Limited
    Inventors: Hideki Sugiura, Hitoshi Iwatsuki
  • Publication number: 20100068645
    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: Application
    Filed: September 17, 2009
    Publication date: March 18, 2010
    Inventors: Hitoshi Iwatsuki, Kimitoshi Yamaguchi, Minoru Masuda, Yutaka Takahashi, Koichi Sakata
  • Patent number: 7642032
    Abstract: A toner including a binder resin; and a colorant, wherein a hexafluoroisopropanol (HFIP)-soluble component satisfies the following relationship: 2,000 ?Mn ?7,000 and 1.5 ?Mn/Mw ?10 wherein Mn represents a number-average molecular weight and Mw represents a weight-average molecular weight.
    Type: Grant
    Filed: October 7, 2004
    Date of Patent: January 5, 2010
    Assignee: Ricoh Company, Limited
    Inventors: Hideki Sugiura, Satoshi Mochizuki, Akihiro Kotsugai, Yasuo Asahina, Osamu Uchinokura, Hisashi Nakajima, Tomoyuki Ichikawa, Shinya Nakayama, Kohichi Sakata, Tomoko Utsumi, Hitoshi Iwatsuki, Yasuaki Iwamoto
  • Patent number: 7592116
    Abstract: The object of the present invention is to provide a carrier for electrophotography which includes a core material and a coating layer comprising particles on a surface of the core material, in which the carrier for electrophotography comprises indium (In) in an amount of 0.0001% by mass to 0.5% by mass. The present invention also provides a developer using the carrier, a developer container, an image forming method, an image forming apparatus, and a process cartridge in each of which the carrier is used.
    Type: Grant
    Filed: November 10, 2005
    Date of Patent: September 22, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Kousuke Suzuki, Tomio Kondou, Shinichiro Yagi, Hitoshi Iwatsuki
  • Publication number: 20090232526
    Abstract: A developer cartridge is provided, which contains developer made of toner and carrier and is detachably mounted in a body of an image formation apparatus. The developer cartridge is configured to include an ID chip in which a carrier content rate of the developer contained in an inner container of the developer cartridge is stored.
    Type: Application
    Filed: March 17, 2009
    Publication date: September 17, 2009
    Inventors: Takuzi Yoneda, Mugijirou Uno, Kousuke Suzuki, Shinichiro Yagi, Masashi Nagayama, Hitoshi Iwatsuki
  • Patent number: 7566521
    Abstract: To provide a toner that can provide long-term removability and high-definition images with reduced image layer thickness and densely-packed toner particles, a developer capable of forming high-quality images using the toner, a toner container for containing the toner, a process cartridge using the toner, an image forming apparatus using the toner, and an image forming method using the toner. The toner of the present invention is a toner having a substantially spherical shape with irregularities on its surface and containing at least a binder resin and a colorant, wherein a surface factor SF-1 that represents the sphericity of toner particles is 105 to 180, a surface factor SF-2 that represents the degree of surface irregularities of the toner particles is correlated with the volume-average diameter of the toner particles, and the toner particles have an inorganic oxide particle-containing layer within 1 ?m from their surfaces.
    Type: Grant
    Filed: July 13, 2007
    Date of Patent: July 28, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Akihiro Kotsugai, Satoshi Mochizuki, Hisashi Nakajima, Yasuo Asahina, Osamu Uchinokura, Masayuki Ishii, Tomoyuki Ichikawa, Shinya Nakayama, Koichi Sakata, Tomoko Utsumi, Hitoshi Iwatsuki, Yasuaki Iwamoto, Hideki Sugiura, Masami Tomita
  • Patent number: 7553598
    Abstract: A carrier contains a core; and a cover layer located overlying the core, wherein the cover layer comprises a binder resin, a first particulate material and a second particulate material, wherein the following relationships are satisfied: 1<(D1/h)<10, and 0.001<(D2/h)<1, wherein D1(?m) represents a volume average particle diameter of the first particulate material, D2(?m) represents a volume average particle diameter of the second particulate material, and h (?m) represents a thickness of the cover layer, and wherein the second particulate material has a volume resistivity of not greater than 1.0×1012 ?·cm.
    Type: Grant
    Filed: March 20, 2006
    Date of Patent: June 30, 2009
    Assignee: Ricoh Company, Limited
    Inventors: Kousuke Suzuki, Tomio Kondoh, Shinichiro Yagi, Hitoshi Iwatsuki
  • Patent number: 7527908
    Abstract: A carrier contains a core material; and a coated film containing a binder resin, and a particulate material, the coated film covering the core material, wherein a ratio (D/h) of an average particle diameter (D) of the particulate material to an average thickness (h) of the coated film is from 0.01 to 1, and wherein the carrier has concavities and convexities on the surface of the carrier, the concavities and convexities having a difference of elevation of from 0.05 to 2.0 ?m.
    Type: Grant
    Filed: April 6, 2006
    Date of Patent: May 5, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Hitoshi Iwatsuki, Tomio Kondou, Shinichiro Yagi, Kousuke Suzuki
  • Publication number: 20090074450
    Abstract: An image forming apparatus including an image bearing member; and a developing device including a developer bearing member, a developer containing portion, a developer supplying passage supplying the developer to the developer bearing member while feeding the developer in a direction, and a developer agitating passage feeding a mixture of the developer fed through the developer supplying passage without used for developing, and the developer used for developing, in the opposite direction. The developer supplying passage, and developer agitating passage are separated from each other except for at least both the end portions. The developer includes a toner and a carrier having a cover layer thereon, which includes a binder resin and a particulate material. The ratio of the volume average particle diameter of the particulate material to the average thickness of the resinous portion of the cover layer is greater than 1 and less than 10.
    Type: Application
    Filed: September 12, 2008
    Publication date: March 19, 2009
    Inventors: Masashi NAGAYAMA, Tomio Kondou, Shinichiro Yagi, Hitoshi Iwatsuki
  • Publication number: 20090041510
    Abstract: An image forming apparatus is provided containing an image bearing member, a developer bearing member, and a developer control member being magnetic. The electrostatic latent image on the image bearing member is developed with a toner to form a toner image. The carrier includes magnetic core particles having a cover layer on the surfaces thereof, including fine particles having a weight average particle diameter of from 0.02 to 0.5 ?m. The carrier has a weight average particle diameter of from 22 to 32 ?m, and a ratio (E10/E100) of from 1.00 to 1.20. The ratio (E10/E100) is a ratio of a total energy (E10) to a total energy (E100) at a leading edge speed of the blade of 10 mm/s and 100 mm/s, respectively, measured using a power rheometer at an angle of approach of ?5°.
    Type: Application
    Filed: August 11, 2008
    Publication date: February 12, 2009
    Inventors: Naoki Imahashi, Tomio Kondou, Kimitoshi Yamaguchi, Hitoshi Iwatsuki
  • Publication number: 20080213684
    Abstract: To provide a carrier for electrophotographic developer including core particles and a cover layer covering the particles, wherein at least one of the carrier to be supplied in a developing apparatus and carrier contained in the developing apparatus has a weight average particle diameter Dw of 22 ?m or more and 32 ?m or less, a ratio Dw/Dp of the weight average particle diameter Dw to the number average particle diameter Dp that satisfies the relationship 1.00?Dw/Dp?1.20, particles whose particle diameter x (?m) is within a range of 0<x<20 in an amount of 7 wt % or less, and particles whose particle diameter y (?m) is within a range of 0<y<36 in an amount of 90 wt % or more and 100 wt % or less.
    Type: Application
    Filed: January 16, 2008
    Publication date: September 4, 2008
    Inventors: Masashi NAGAYAMA, Tomio Kondou, Shinichiro Yagi, Hitoshi Iwatsuki
  • Publication number: 20080213682
    Abstract: Provided is a toner for developing electrostatic image, comprising particles of oil phase containing at least a toner composition and/or toner composition precursor in an aqueous medium, wherein the toner composition and/or toner composition precursor comprises an organic-modified layered inorganic mineral prepared by modifying at least partially an ion of a layered inorganic mineral into an organic ion, and the organic ion-modification ratio X satisfies the relation of 100<X(%)<150 in the organic-modified layered inorganic mineral.
    Type: Application
    Filed: February 29, 2008
    Publication date: September 4, 2008
    Inventors: Akinori SAITOH, Masahide Yamada, Osamu Uchinokura, Junichi Awamura, Tomomi Suzuki, Shinichiro Yagi, Tomio Kondou, Masashi Nagayama, Hitoshi Iwatsuki
  • Publication number: 20080152393
    Abstract: A carrier for electrophotographic developer that comprises a particle of core material and a coating layer that coats the particle of core material, wherein a toner and a carrier are supplied into a developing device where a toner and a carrier being contained, and the surplus developer within the developing device is discharged, a coating layer on at least one of the supplied carrier and the carrier contained in the developing device comprises a white conductive fine particle that includes tin dioxide and indium oxide on a base material.
    Type: Application
    Filed: December 18, 2007
    Publication date: June 26, 2008
    Inventors: Masashi NAGAYAMA, Tomio Kondou, Shinichiro Yagi, Hitoshi Iwatsuki
  • Patent number: 7381513
    Abstract: A carrier containing a core material and a resin coating layer located overlying the surface of the core material. The resin coating layer contains resin and electroconductive particles having an oil absorption amount of from 10 to 300 ml/100 g. The electroconductive particle contains a base material particle and an electroconductive coating layer located overlying the surface of the base material particle. The electroconductive coating layer contains an underlayer containing tin dioxide and an upper layer containing indium oxide and tin dioxide, located overlying the underlayer.
    Type: Grant
    Filed: July 27, 2005
    Date of Patent: June 3, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Kohsuke Suzuki, Tomio Kondoh, Shinichiro Yagi, Hitoshi Iwatsuki
  • Publication number: 20080096121
    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: Application
    Filed: October 11, 2007
    Publication date: April 24, 2008
    Inventors: Hitoshi IWATSUKI, Tomio Kondou, Shinichiro Yagi, Masashi Nagayama
  • Publication number: 20080014527
    Abstract: To provide a toner that can provide long-term removability and high-definition images with reduced image layer thickness and densely-packed toner particles, a developer capable of forming high-quality images using the toner, a toner container for containing the toner, a process cartridge using the toner, an image forming apparatus using the toner, and an image forming method using the toner. The toner of the present invention is a toner having a substantially spherical shape with irregularities on its surface and containing at least a binder resin and a colorant, wherein a surface factor SF-1 that represents the sphericity of toner particles is 105 to 180, a surface factor SF-2 that represents the degree of surface irregularities of the toner particles is correlated with the volume-average diameter of the toner particles, and the toner particles have an inorganic oxide particle-containing layer within 1 ?m from their surfaces.
    Type: Application
    Filed: July 13, 2007
    Publication date: January 17, 2008
    Inventors: Akihiro Kotsugai, Satoshi Mochizuki, Hisashi Nakajima, Yasuo Asahina, Osamu Uchinokura, Masayuki Ishii, Tomoyuki Ichikawa, Shinya Nakayama, Koichi Sakata, Tomoko Utsumi, Hitoshi Iwatsuki, Yasuaki Iwamoto, Hideki Sugiura, Masami Tomita