Patents by Inventor Toyoshi Sawada

Toyoshi Sawada 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).

  • Patent number: 9804515
    Abstract: A toner of the present invention includes at least a colorant and a resin, has crystallinity CX or 20 or greater, and has a dynamic viscoelasticity characteristic in which a logarithmic value Log G?(50) of storage elastic modulus (Pa) at 50° C. is from 6.5 to 8.0 and a logarithmic value Log G?(65) of storage elastic modulus (Pa) at 65° C. is from 4.5 to 6.0, when the dynamic viscoelasticity characteristic is measured by temperature sweep from 40° C., at a frequency of 1 Hz, at a strain amount control of 0.1%, and at a temperature elevating rate of 2° C./min.
    Type: Grant
    Filed: August 30, 2013
    Date of Patent: October 31, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideki Sugiura, Shinya Nakayama, Toyoshi Sawada
  • Patent number: 9785075
    Abstract: Provided is a toner containing a binder resin. The binder resin contains a crystalline resin. The toner has a maximum endothermic peak temperature (P1) of from 50° C. to 80° C. and a total endothermic amount (Q) of from 35 J/g to 90 J/g at a first temperature elevation of differential scanning calorimetry. A ratio (Qp/Q) of a total endothermic amount (Qp) of the toner in a temperature range of from 20° C. to the maximum endothermic peak temperature (P1) to the total endothermic amount (Q) of the toner is from 0.65 to 0.83.
    Type: Grant
    Filed: October 11, 2013
    Date of Patent: October 10, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinya Nakayama, Atsushi Yamamoto, Minoru Masuda, Susumu Chiba, Toyoshi Sawada, Hiroshi Yamashita
  • Patent number: 9594322
    Abstract: A toner is provided. The toner includes a crosslinked polyester resin, and a block copolymer. The crosslinked polyester resin includes a diol component, which includes an aliphatic diol component having 3 to 10 carbon atoms in an amount of 50% by mole, and a crosslinked component, which is at least one of a crosslinked component of an aliphatic alcohol having three or more valences and a crosslinked component of an aliphatic acid having three or more valences, and the block copolymer includes a crystalline segment (a) and a non-crystalline segment (b). The toner has a first glass transition temperature (Tg1st) of from 20° C. to 50° C., which is determined by subjecting the toner to differential scanning calorimetry (DSC) and measuring a glass transition temperature in a first temperature rising process in the differential scanning calorimetry (DSC).
    Type: Grant
    Filed: August 28, 2014
    Date of Patent: March 14, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Suzuka Amemori, Tsuyoshi Sugimoto, Akinori Saito, Toyoshi Sawada, Keiji Makabe
  • Publication number: 20160223926
    Abstract: Provided is a resin for a toner, which is a copolymer including a crystalline segment, and having a maximum elastic stress value at 100° C. (ES-100) of 1,000 Pa or less, and a maximum elastic stress value at 70° C. (ES70) of 1,000 Pa or greater when the temperature is lowered from 100° C. to 70° C., where the maximum elastic stress values are measured according to a large amplitude oscillatory shear procedure.
    Type: Application
    Filed: August 13, 2014
    Publication date: August 4, 2016
    Inventors: Azumi MIYAAKE, Daisuke ASAHINA, Toyoshi SAWADA, Hiroshi YAMASHITA, Tsuyoshi SUGIMOTO, Shinya NAKAYAMA, Susumu CHIBA, Satoyuki SEKIGUCHI
  • Publication number: 20160091812
    Abstract: A toner includes a binder resin including a copolymer resin containing structural units derived from crystalline and non-crystalline resins, respectively. Spin-spin relaxation time (t50) of the toner at 50° C. measured by pulse NMR is ?0.05 msec., spin-spin relaxation time (t130) at 130° C. when warmed from 50° C. to 130° C. is >15 msec., and spin-spin relaxation time (t?70) at 70° C. when cooled from 130° C. to 70° C. is ?1.00 msec. A binarized image obtained by binarizing a phase image of the toner observed by a tapping mode AFM based on intermediate value between maximum and minimum phase difference values in the phase image includes first phase difference images constituted by large phase-difference portions and a second phase difference image constituted by a small phase-difference portion. The first phase difference images are dispersed in the second phase difference image. The dispersion diameter of the first phase difference images is 150 nm or less.
    Type: Application
    Filed: November 27, 2013
    Publication date: March 31, 2016
    Inventors: Keiji MAKABE, Tsuyoshi SUGIMOTO, Akinori SAITO, Suzuka AMEMORI, Toyoshi SAWADA, Hiroshi YAMASHITA, Shinya NAKAYAMA, Atsushi YAMAMOTO, Daisuke ASAHINA, Satoyuki SEKIGUCHI
  • Patent number: 9176406
    Abstract: Toner contains a binder resin containing a crystalline resin having a urethane and/or urea bonding; and a colorant, wherein in a diffraction spectrum of the toner as measured by an X-ray diffraction instrument, a ratio {C/(C+A)} of an integral intensity C of the spectrum derived from the crystalline structure to an integral intensity A of the spectrum derived from the non-crystalline structure is 0.12 or greater, wherein the toner satisfies the following relation 1: T1?T2?30° C. (Relation 1), where T1 represents the maximum endothermic peak in the first temperature rising from 0° C. to 100° C. at the temperature rising rate of 10° C./min and T2 represents the maximum exothermic peak in the first temperature falling from 100° C. to 0° C. at the temperature falling rate of 10° C./min as T1 and T2 are measured by diffraction scanning calorimetry (DSC).
    Type: Grant
    Filed: August 5, 2013
    Date of Patent: November 3, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Satoyuki Sekiguchi, Hiroshi Yamashita, Minoru Masuda, Susumu Chiba, Tatsuya Morita, Atsushi Yamamoto, Shinya Nakayama, Masahide Yamada, Kohsuke Nagata, Keiji Makabe, Toyoshi Sawada
  • Patent number: 9176409
    Abstract: Toner contains a mother toner particle containing a binder resin and a coloring agent and an external additive to cover the mother toner particle, wherein the external additive contains a resin particle, wherein the resin particle has an outer shell layer formed of silica or modified silica, wherein the resin particle has a non-spherical form with a shape factor (SF) of 1.20 or greater as calculated by the following relationship 1, Shape factor(SF)=[(Absolute maximum length of particle)2/Projected area of particle)]×(?/4)??Relation 1.
    Type: Grant
    Filed: October 7, 2013
    Date of Patent: November 3, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Masayuki Ishii, Toyoshi Sawada
  • Patent number: 9146487
    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: Grant
    Filed: July 1, 2013
    Date of Patent: September 29, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Toyoshi Sawada, Shigenori Yaguchi, Hiroshi Tohmatsu, Hitoshi Iwatsuki, Toyoaki Tano, Hiroyuki Kishida, Yumiko Yagi
  • Publication number: 20150248073
    Abstract: Provided is a toner containing a binder resin. The binder resin contains a crystalline resin. The toner has a maximum endothermic peak temperature (P1) of from 50° C. to 80° C. and a total endothermic amount (Q) of from 35 J/g to 90 J/g at a first temperature elevation of differential scanning calorimetry. A ratio (Qp/Q) of a total endothermic amount (Qp) of the toner in a temperature range of from 20° C. to the maximum endothermic peak temperature (P1) to the total endothermic amount (Q) of the toner is from 0.65 to 0.83.
    Type: Application
    Filed: October 11, 2013
    Publication date: September 3, 2015
    Inventors: Shinya Nakayama, Atsushi Yamamoto, Minoru Masuda, Susumu Chiba, Toyoshi Sawada, Hiroshi Yamashita
  • Publication number: 20150227066
    Abstract: A toner of the present invention includes at least a colorant and a resin, has crystallinity CX or 20 or greater, and has a dynamic viscoelasticity characteristic in which a logarithmic value Log G?(50) of storage elastic modulus (Pa) at 50° C. is from 6.5 to 8.0 and a logarithmic value Log G?(65) of storage elastic modulus (Pa) at 65° C. is from 4.5 to 6.0, when the dynamic viscoelasticity characteristic is measured by temperature sweep from 40° C., at a frequency of 1 Hz, at a strain amount control of 0.1%, and at a temperature elevating rate of 2° C./min.
    Type: Application
    Filed: August 30, 2013
    Publication date: August 13, 2015
    Inventors: Hideki Sugiura, Shinya Nakayama, Toyoshi Sawada
  • Publication number: 20150212442
    Abstract: A toner is provided. The toner includes mother toner particles. Each mother toner particle includes a binder resin and inorganic-layer-containing resin particles. Each inorganic-layer-containing resin particle includes a resin particle and an inorganic layer on the surface of the resin particle.
    Type: Application
    Filed: January 28, 2015
    Publication date: July 30, 2015
    Inventors: Masayuki ISHII, Toyoshi SAWADA, Keiji MAKABE
  • Publication number: 20150072287
    Abstract: A toner is provided. The toner includes a crosslinked polyester resin, and a block copolymer. The crosslinked polyester resin includes a diol component, which includes an aliphatic diol component having 3 to 10 carbon atoms in an amount of 50% by mole, and a crosslinked component, which is at least one of a crosslinked component of an aliphatic alcohol having three or more valences and a crosslinked component of an aliphatic acid having three or more valences, and the block copolymer includes a crystalline segment (a) and a non-crystalline segment (b). The toner has a first glass transition temperature (Tg1st) of from 20° C. to 50° C., which is determined by subjecting the toner to differential scanning calorimetry (DSC) and measuring a glass transition temperature in a first temperature rising process in the differential scanning calorimetry (DSC).
    Type: Application
    Filed: August 28, 2014
    Publication date: March 12, 2015
    Inventors: Suzuka AMEMORI, Tsuyoshi SUGIMOTO, Akinori SAITO, Toyoshi SAWADA, Keiji MAKABE
  • Patent number: 8927186
    Abstract: A toner for use in developing an electrostatic latent image is provided. The toner includes a colored particulate material including at least a binder resin and a colorant; and an external additive present on a surface of the colored particulate material and including a particulate crystalline hydroxyapatite. The particulate crystalline hydroxyapatite has an average aspect ratio of not less than 3 and less than 30.
    Type: Grant
    Filed: November 23, 2010
    Date of Patent: January 6, 2015
    Assignee: Ricoh Company, Limited
    Inventors: Masayuki Ishii, Toyoshi Sawada
  • Patent number: 8903270
    Abstract: A developing device including a developer bearing member containing a magnetic field generator having multiple magnetic poles and a developer containing chamber is provided. The developer containing chamber contains a two-component developer comprising magnetic carrier particles having a saturated magnetization of 58 to 70 emu/g in a magnetic field of 1KOe and toner particles, and has a divider to define an upper supply chamber and a lower collection chamber. The supply chamber includes a supply conveyer to supply the two-component developer to the developer bearing member at an upstream side from the developing area. The collection chamber includes a collection conveyer to collect the two-component developer from the developer bearing member at a downstream side from the developing area. The multiple magnetic poles includes three developer bearing poles capable of bearing the developer on its surface.
    Type: Grant
    Filed: March 5, 2012
    Date of Patent: December 2, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Koichi Sakata, Shigenori Yaguchi, Toyoshi Sawada, Hitoshi Iwatsuki, Hiroyuki Kishida
  • Publication number: 20140272696
    Abstract: Toner contains a mother toner particle that contains a crystalline resin; and wax; and a coloring agent, wherein the area of endothermic peak derived from the crystalline resin during a first temperature rising as measured by differential scanning calorimetry is at least 20 J/g, wherein the ratio of the area of endothermic peak derived from the wax during a second time temperature rising as measured by differential scanning calorimetry (DSC) to the area of endothermic peak derived from the wax during a first time temperature rising as measured by differential scanning calorimetry is at least 0.50, wherein the ratio of the area of endothermic peak derived from the wax during a first time temperature rising as measured by differential scanning calorimetry to the area of endothermic peak derived from the crystalline resin during a first temperature rising as measured by differential scanning calorimetry is at least 0.10.
    Type: Application
    Filed: February 4, 2014
    Publication date: September 18, 2014
    Inventors: Hiroshi YAMASHITA, Toyoshi Sawada, Hideyuki Santo
  • Publication number: 20140272698
    Abstract: Toner contains a binder resin containing two or more kinds of crystalline resins; and a coloring agent, wherein the two or more kinds of crystalline resins have at least two endothermic peak temperatures in a set of endothermic peak temperatures of the two or more kinds of crystalline resins as measured by differential scanning calorimetry (DSC).
    Type: Application
    Filed: March 14, 2014
    Publication date: September 18, 2014
    Inventors: Masahide YAMADA, Atsushi Yamamoto, Satoyuki Sekiguchi, Keiji Makabe, Kohsuke Nagata, Toyoshi Sawada
  • Patent number: 8785093
    Abstract: An image forming toner, including a mother particle including a paraffin wax having a melting point of from 60 to 90° C. and a binder resin, wherein the mother particle has an endothermic peak of the paraffin wax of from 2.0 J/g to 5.5 J/g when measured by a DSC and an aspect ratio of from 0.8 to 0.90.
    Type: Grant
    Filed: October 29, 2008
    Date of Patent: July 22, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Toyoshi Sawada, Tomomi Suzuki, Tsuneyasu Nagatomo, Satoshi Kojima
  • Patent number: 8787804
    Abstract: A developing device including a developer container and a developer bearing member is provided. The developer container contains a two-component developer comprising toner particles and magnetic carrier particles having a ten-point average surface roughness Rz of 0.5 to 3.0 ?m. The developer bearing member is a cylindrical member containing a magnetic field generator having multiple magnetic poles. The developer bearing member is adapted to bear the two-component developer on a surface thereof and to convey the two-component developer as the surface rotates. The developer bearing member has a ten-point average surface roughness Rz of 10 to 30 ?m. The multiple magnetic poles include three developer bearing poles each adapted to generate a magnetic field having a strength enough for retaining the two-component developer on a surface of the developer bearing member. The three developer bearing poles consist of a developing pole, a pre-developing pole, and a post-developing pole.
    Type: Grant
    Filed: June 18, 2012
    Date of Patent: July 22, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroyuki Kishida, Shigenori Yaguchi, Toyoshi Sawada, Toyoaki Tano, Koichi Sakata
  • Patent number: 8778587
    Abstract: A carrier for developing an electrostatic latent image, including a particulate core material having a magnetism having developed spontaneous magnetization; and a covering layer comprising an electroconductive material, covering the surface of the particulate core material, wherein the carrier has an electrical resistivity Log R [?cm] of from 8.0 to 12.0 when measured by a method, including filling the carrier in a cell containing a pair of facing electrodes, each having a surface area of 2×4 [cm2] with a gap of 2 [mm] therebetween; and applying a DC voltage of 1,000 [V] therebetween to measure a DC resistivity, and a weight-average particle diameter (Dw) of from 25 to 45 ?m.
    Type: Grant
    Filed: October 10, 2012
    Date of Patent: July 15, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Kimitoshi Yamaguchi, Shigenori Yaguchi, Toyoshi Sawada, Hiroshi Tohmatsu, Hitoshi Iwatsuki, Toyoaki Tano
  • Patent number: 8778583
    Abstract: A toner including a mother particle and an external additive covering a surface of the mother particle is provided. The mother particle includes a binder resin, a colorant, and a release agent. The external additive includes a particulate cellulose having a number average particle diameter within a range of 15 to 105 nm.
    Type: Grant
    Filed: November 16, 2012
    Date of Patent: July 15, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Masayuki Ishii, Toyoshi Sawada