Patents by Inventor Hitoshi Itabashi

Hitoshi Itabashi 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: 10295922
    Abstract: A toner containing a toner particle including a binder resin, a resin A having a pKa of 6.0-9.0, and a pigment having a pKb of 4.0-7.0, wherein the pKa is an acid dissociation constant measured by preparing a resin solution in which 1.0 part by mass of the resin A, 70.0 parts by mass of toluene and 30.0 parts by mass of ethanol are mixed, and carrying out neutralization titration with a potassium hydroxide ethanol solution of 0.1 mol/L, and the pKb is a basic dissociation constant measured by preparing a pigment dispersion in which 10.0 parts by mass of the pigment, 140.0 parts by mass of toluene and 60.0 parts by mass of ethanol are mixed, and carrying out neutralization titration with a hydrochloric acid ethanol solution of 0.1 mol/L.
    Type: Grant
    Filed: March 13, 2017
    Date of Patent: May 21, 2019
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Yuhei Terui, Yu Yoshida, Haruko Kubo, Hitoshi Itabashi
  • Patent number: 10095144
    Abstract: In a toner containing a binder resin, a pigment, a pigment dispersant, and a fixing assistant, the pigment dispersant has a structure represented by formula (1) or a tautomer thereof and a polymer moiety, the binder resin and the fixing assistant satisfy formula (2), and a hydrophobic parameter HP1 of the pigment dispersant and a hydrophobic parameter HP2 of the fixing assistant satisfy formula (3).
    Type: Grant
    Filed: August 26, 2016
    Date of Patent: October 9, 2018
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yu Yoshida, Yuhei Terui, Haruko Kubo, Hitoshi Itabashi
  • Patent number: 10078285
    Abstract: Provided is a toner comprising a toner particle containing: a binder resin; a pigment; a resin having an acidic functional group; and a fixing auxiliary agent, wherein the pigment is a pigment having a structure derived from a basic compound, and the binder resin and the fixing auxiliary agent satisfy following Formula (1): (TgA?TgB)?5.0° C.??Formula (1) and given HP1 as a hydrophobic parameter of the resin having an acidic functional group and HP2 as a hydrophobic parameter of the fixing auxiliary agent, the HP1 is at least 0.60, and following Formula (2) is satisfied: |HP1?HP2|?0.30??Formula (2).
    Type: Grant
    Filed: March 13, 2017
    Date of Patent: September 18, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Haruko Kubo, Yuhei Terui, Yu Yoshida, Hitoshi Itabashi
  • Patent number: 10012922
    Abstract: A toner comprising a toner particle containing a pigment, a resin A and a resin B, wherein the pigment is a pigment having a structure derived from a basic compound, the resin A has an acidic functional group, the resin B has an acid value of at least 2.0 mg KOH/g, the resin B has a glass transition temperature TgB of at least 50° C., and the hydrophobic parameter HPA of the resin A and the hydrophobic parameter of the resin B satisfy the following formulae: HPA?0.60 HPB?0.70 HPA?HPB>0.
    Type: Grant
    Filed: March 13, 2017
    Date of Patent: July 3, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Yu Yoshida, Yuhei Terui, Haruko Kubo, Hitoshi Itabashi
  • Patent number: 9996018
    Abstract: In a toner containing a resin, a pigment, and a pigment dispersant, the resin contains a polar resin having an acid value of 2.0 to 30.0 mgKOH/g, and the pigment dispersant has the structure represented by the following formula (1) and a polymer moiety bonded thereto.
    Type: Grant
    Filed: August 30, 2016
    Date of Patent: June 12, 2018
    Assignee: Canon Kabushiki Kaisha
    Inventors: Haruko Kubo, Yu Yoshida, Yuhei Terui, Hitoshi Itabashi
  • Patent number: 9964879
    Abstract: Provided is a toner comprising a toner particle containing a binder resin, a resin A, and a pigment, wherein the resin A has a pKa of at least 6.0 and not more than 9.0, and also has a hydrophobic parameter HPA of at least 0.65 and not more than 0.95.
    Type: Grant
    Filed: March 13, 2017
    Date of Patent: May 8, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Yuhei Terui, Yu Yoshida, Haruko Kubo, Hitoshi Itabashi
  • Publication number: 20170269491
    Abstract: Provided is a toner comprising a toner particle containing a binder resin, a resin A, and a pigment, wherein the resin A has a pKa of at least 6.0 and not more than 9.0, and also has a hydrophobic parameter HPA of at least 0.65 and not more than 0.95.
    Type: Application
    Filed: March 13, 2017
    Publication date: September 21, 2017
    Inventors: Yuhei Terui, Yu Yoshida, Haruko Kubo, Hitoshi Itabashi
  • Publication number: 20170269496
    Abstract: Provided is a toner comprising a toner particle containing: a binder resin; a pigment; a resin having an acidic functional group; and a fixing auxiliary agent, wherein the pigment is a pigment having a structure derived from a basic compound, and the binder resin and the fixing auxiliary agent satisfy following Formula (1): (TgA?TgB)?5.0° C.??Formula (1) and given HP1 as a hydrophobic parameter of the resin having an acidic functional group and HP2 as a hydrophobic parameter of the fixing auxiliary agent, the HP1 is at least 0.60, and following Formula (2) is satisfied: |HP1?HP2|?0.30??Formula (2).
    Type: Application
    Filed: March 13, 2017
    Publication date: September 21, 2017
    Inventors: Haruko Kubo, Yuhei Terui, Yu Yoshida, Hitoshi Itabashi
  • Publication number: 20170269495
    Abstract: A toner containing a toner particle including a binder resin, a resin A having a pKa of 6.0-9.0, and a pigment having a pKb of 4.0-7.0, wherein the pKa is an acid dissociation constant measured by preparing a resin solution in which 1.0 part by mass of the resin A, 70.0 parts by mass of toluene and 30.0 parts by mass of ethanol are mixed, and carrying out neutralization titration with a potassium hydroxide ethanol solution of 0.1 mol/L, and the pKb is a basic dissociation constant measured by preparing a pigment dispersion in which 10.0 parts by mass of the pigment, 140.0 parts by mass of toluene and 60.0 parts by mass of ethanol are mixed, and carrying out neutralization titration with a hydrochloric acid ethanol solution of 0.1 mol/L.
    Type: Application
    Filed: March 13, 2017
    Publication date: September 21, 2017
    Inventors: Yuhei Terui, Yu Yoshida, Haruko Kubo, Hitoshi Itabashi
  • Publication number: 20170269494
    Abstract: A toner comprising a toner particle containing a pigment, a resin A and a resin B, wherein the pigment is a pigment having a structure derived from a basic compound, the resin A has an acidic functional group, the resin B has an acid value of at least 2.0 mg KOH/g, the resin B has a glass transition temperature TgB of at least 50° C., and the hydrophobic parameter HPA of the resin A and the hydrophobic parameter of the resin B satisfy the following formulae: HPA?0.60 HPB?0.70 HPA?HPB>0.
    Type: Application
    Filed: March 13, 2017
    Publication date: September 21, 2017
    Inventors: Yu Yoshida, Yuhei Terui, Haruko Kubo, Hitoshi Itabashi
  • Publication number: 20170060013
    Abstract: In a toner containing a binder resin, a pigment, a pigment dispersant, and a fixing assistant, the pigment dispersant has a structure represented by formula (1) or a tautomer thereof and a polymer moiety, the binder resin and the fixing assistant satisfy formula (2), and a hydrophobic parameter HP1 of the pigment dispersant and a hydrophobic parameter HP2 of the fixing assistant satisfy formula (3).
    Type: Application
    Filed: August 26, 2016
    Publication date: March 2, 2017
    Inventors: Yu Yoshida, Yuhei Terui, Haruko Kubo, Hitoshi Itabashi
  • Publication number: 20170060015
    Abstract: In a toner containing a resin, a pigment, and a pigment dispersant, the resin contains a polar resin having an acid value of 2.0 to 30.0 mgKOH/g, and the pigment dispersant has the structure represented by the following formula (1) and a polymer moiety bonded thereto.
    Type: Application
    Filed: August 30, 2016
    Publication date: March 2, 2017
    Inventors: Haruko Kubo, Yu Yoshida, Yuhei Terui, Hitoshi Itabashi
  • Patent number: 9575426
    Abstract: It is an object of the present invention to provide a toner capable of being fixed at low energy and forming an image with high resistance to external forces, such as rubbing and scratching. The object is achieved by a toner including toner particles that contain a binder resin and a colorant, a sea-island structure including a sea portion composed of the crystalline resin C serving as a main component and island portions composed of the amorphous resin A serving as a main component is observed at the observation of a cross section of each of the toner particles.
    Type: Grant
    Filed: June 27, 2014
    Date of Patent: February 21, 2017
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsutomu Shimano, Shintaro Noji, Hitoshi Itabashi
  • Patent number: 9505723
    Abstract: The present invention provides a dispersant excellent in the solubility to a solvent, the adsorption power to a coloring material, and the coloring material dispersibility, and reduced in the self-coloring property, a compound and a polymerizable compound for preparing the dispersant, and a toner using the dispersant. The dispersant has a structure in which a structure represented by the following specific formula (3) or a tautomer thereof is bonded with a polymer, and the toner contains the dispersant.
    Type: Grant
    Filed: January 5, 2016
    Date of Patent: November 29, 2016
    Assignees: CANON KABUSHIKI KAISHA, CANON FINETECH INC.
    Inventors: Haruko Kubo, Suzuka Ueno, Junko Chizuwa, Tomoya Yamamoto, Hitoshi Itabashi, Yuhei Terui, Yu Yoshida, Yasuaki Murai, Takayuki Toyoda
  • Publication number: 20160130233
    Abstract: The present invention provides a dispersant excellent in the solubility to a solvent, the adsorption power to a coloring material, and the coloring material dispersibility, and reduced in the self-coloring property, a compound and a polymerizable compound for preparing the dispersant, and a toner using the dispersant. The dispersant has a structure in which a structure represented by the following specific formula (3) or a tautomer thereof is bonded with a polymer, and the toner contains the dispersant.
    Type: Application
    Filed: January 5, 2016
    Publication date: May 12, 2016
    Inventors: Haruko Kubo, Suzuka Ueno, Junko Chizuwa, Tomoya Yamamoto, Hitoshi Itabashi, Yuhei Terui, Yu Yoshida, Yasuaki Murai, Takayuki Toyoda
  • Patent number: 9223240
    Abstract: Since a charge amount of a toner and a charge rise characteristic thereof are liable to be influenced by the change in temperature and humidity condition, the change in image density occurs in printing, and in particular, in high temperature and high humidity environment, inconveniences, such as image fogging, occur due to non-uniformity of the charge amount distribution. In a toner including toner particles obtained by dispersing a monomer composition containing a polymerizable monomer and a colorant in an aqueous medium to form droplets and polymerizing the polymerizable monomer in the droplets, the toner particles contain a polymer formed by a polymerization reaction of the polymerizable monomer and a metal compound having a vinyl group.
    Type: Grant
    Filed: September 5, 2012
    Date of Patent: December 29, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takashi Kenmoku, Hitoshi Itabashi, Akane Masumoto
  • Patent number: 9098002
    Abstract: A toner including toner particles, each of which comprising a charging component, a polymer having a partial structure represented by the following formula (1) as the side chain, and a colorant: (R1 represents a hydroxyl group, a carboxyl group, an alkyl group having 1 to 18 carbon atoms, or an alkoxyl group having 1 to 18 carbon atoms; R2 represents a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 18 carbon atoms, or an alkoxyl group having 1 to 18 carbon atoms; m represents an integer of 0 to 3; if m is 2 or 3, R1 can be each independently selected; n represents an integer of 1 to 3; and * represents a coupling site in the polymer.
    Type: Grant
    Filed: May 17, 2012
    Date of Patent: August 4, 2015
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Takashi Kenmoku, Hitoshi Itabashi, Akane Masumoto
  • Patent number: 9098003
    Abstract: A toner including toner particles containing a binder resin, a colorant and a charge controlling agent, wherein the charge controlling agent is a polymer A having a structure “a” represented by formula (1), and the polymer A has a weight average molecular weight (Mw) of 1,000 to 100,000: wherein R1 represents a hydroxyl group, a carboxyl group, an alkyl group having 1 to 18 carbon atoms, or an alkoxyl group having 1 to 18 carbon atoms, R2 represents a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 18 carbon atoms, or an alkoxyl group having 1 to 18 carbon atoms, and g represents an integer of 1 to 3 and h represents an integer of 0 to 3, wherein when h is 2 or 3, R1 can be each independently selected.
    Type: Grant
    Filed: May 17, 2012
    Date of Patent: August 4, 2015
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Akane Masumoto, Hitoshi Itabashi, Takashi Kenmoku
  • Patent number: 9029056
    Abstract: Provided is a toner having high charging rapidity to reach a sufficient charging amount in a short time, high stability of charging from the initial stage to a time when a large amount of sheets is printed out, and high stability of charging under a high temperature and high humidity. In a toner including toner particles, each of which contains at least a binder resin, a colorant, and a charge controlling resin, the charge controlling resin is a copolymer of a structure A having at least a specific salicylic acid derivative structure and a structure B having sulfonic acid or sulfonic acid ester as a substituent.
    Type: Grant
    Filed: May 17, 2012
    Date of Patent: May 12, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takashi Kenmoku, Hitoshi Itabashi, Akane Masumoto
  • Patent number: 8975000
    Abstract: The method of producing polymerized toner, the method including: dispersing a polymerizable monomer composition containing at least a polymerizable monomer and a colorant in an aqueous medium; and polymerizing the polymerizable monomer in the aqueous medium with a polymerization initiator to produce toner particles, and is characterized in that a polymerization initiator which has a specific structure and the hydrogen bond dissociation energies of which satisfy specific relationships is used as the polymerization initiator.
    Type: Grant
    Filed: July 24, 2008
    Date of Patent: March 10, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventors: Atsushi Tani, Norikazu Fujimoto, Hitoshi Itabashi