Patents by Inventor Chika HAMA

Chika HAMA 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).

  • SILICA COMPOSITE PARTICLES AND METHOD OF PREPARING THE SAME
    Publication number: 20160137848
    Abstract: Silica composite particles in which a silica particle surface is sequentially surface-treated with a titanium compound in which an organic group is bonded to a titanium atom through an oxygen atom, and a hydrophobizing agent are provided, in which a titanium content in the silica composite particles measured using fluorescence X-ray is from 0.001% by weight to 10% by weight; a titanium content of a surface layer of the silica composite particles satisfies the following Formula (1); an average particle diameter of the silica composite particles is from 30 nm to 500 nm; and a particle size distribution index of the silica composite particles is from 1.1 to 1.5: 0.6<Y/X<1.8??(1) wherein X represents a titanium content in silica composite particles measured using fluorescence X-ray, and Y represents a titanium content of the silica composite particle surface obtained by XPS measurement.
    Type: Application
    Filed: January 26, 2016
    Publication date: May 19, 2016
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Takeshi IWANAGA, Yuka ZENITANI, Yasunobu KASHIMA, Chika HAMA, Yoshifumi IIDA
  • Silica composite particles and method of preparing the same
    Patent number: 9243145
    Abstract: Silica composite particles in which a silica particle surface is sequentially surface-treated with a titanium compound in which an organic group is bonded to a titanium atom through an oxygen atom, and a hydrophobizing agent are provided, in which a titanium content in the silica composite particles measured using fluorescence X-ray is from 0.001% by weight to 10% by weight; a titanium content of a surface layer of the silica composite particles satisfies the following Formula (1); an average particle diameter of the silica composite particles is from 30 nm to 500 nm; and a particle size distribution index of the silica composite particles is from 1.1 to 1.5: 0.6<Y/X<1.8??(1) wherein X represents a titanium content in silica composite particles measured using fluorescence X-ray, and Y represents a titanium content of the silica composite particle surface obtained by XPS measurement.
    Type: Grant
    Filed: July 3, 2013
    Date of Patent: January 26, 2016
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Takeshi Iwanaga, Yuka Zenitani, Yasunobu Kashima, Chika Hama, Yoshifumi Iida
  • Electrostatic charge image developing toner, electrostatic charge image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method
    Patent number: 8999617
    Abstract: An electrostatic charge image developing toner includes toner particles and silica particles that have a titanium content of from 0.001% by weight to 10% by weight in a surface layer, an average particle diameter of from 30 nm to 500 nm, and a particle size distribution index of from 1.1 to 1.5, and are surface-treated with a titanium compound in which an organic group is bonded to a titanium atom via an oxygen atom, and a hydrophobizing agent in sequence.
    Type: Grant
    Filed: July 25, 2013
    Date of Patent: April 7, 2015
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Yoshifumi Iida, Takeshi Iwanaga, Yuka Zenitani, Yasunobu Kashima, Chika Hama
  • SILICA COMPOSITE PARTICLES AND METHOD OF PRODUCING THE SAME
    Publication number: 20140356624
    Abstract: Disclosed are silica composite particles in which silica particles are subjected to surface treatment with an aluminum compound in which an organic group is bonded to an aluminum atom through an oxygen atom, and an aluminum surface coverage is from 0.01 atomic % to 30 atomic %, an average particle size is from 30 nm to 500 nm, and a particle size distribution index is from 1.1 to 1.5.
    Type: Application
    Filed: October 22, 2013
    Publication date: December 4, 2014
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Chika HAMA, Yoshifumi IIDA, Hiroyoshi OKUNO
  • ELECTROSTATIC CHARGE IMAGE DEVELOPING TONER, ELECTROSTATIC CHARGE IMAGE DEVELOPER, TONER CARTRIDGE, PROCESS CARTRIDGE, IMAGE FORMING APPARATUS, AND IMAGE FORMING METHOD
    Publication number: 20140295340
    Abstract: An electrostatic charge image developing toner includes toner particles and silica particles that have a titanium content of from 0.001% by weight to 10% by weight in a surface layer, an average particle diameter of from 30 nm to 500 nm, and a particle size distribution index of from 1.1 to 1.5, and are surface-treated with a titanium compound in which an organic group is bonded to a titanium atom via an oxygen atom, and a hydrophobizing agent in sequence.
    Type: Application
    Filed: July 25, 2013
    Publication date: October 2, 2014
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Yoshifumi IIDA, Takeshi IWANAGA, Yuka ZENITANI, Yasunobu KASHIMA, Chika HAMA
  • SILICA COMPOSITE PARTICLES AND METHOD OF PREPARING THE SAME
    Publication number: 20140212667
    Abstract: Silica composite particles in which a silica particle surface is sequentially surface-treated with a titanium compound in which an organic group is bonded to a titanium atom through an oxygen atom, and a hydrophobizing agent are provided, in which a titanium content in the silica composite particles measured using fluorescence X-ray is from 0.001% by weight to 10% by weight; a titanium content of a surface layer of the silica composite particles satisfies the following Formula (1); an average particle diameter of the silica composite particles is from 30 nm to 500 nm; and a particle size distribution index of the silica composite particles is from 1.1 to 1.5: 0.6<Y/X<1.8??(1) wherein X represents a titanium content in silica composite particles measured using fluorescence X-ray, and Y represents a titanium content of the silica composite particle surface obtained by XPS measurement.
    Type: Application
    Filed: July 3, 2013
    Publication date: July 31, 2014
    Inventors: Takeshi IWANAGA, Yuka ZENITANI, Yasunobu KASHIMA, Chika HAMA, Yoshifumi IIDA
  • Method of preparing silica composite particles
    Patent number: 8779173
    Abstract: Provided is a method of preparing silica composite particles, including treating silica particles, wherein the treating is for treating the silica particles with a metal compound in which a metal atom binds to an organic group via an oxygen atom, in supercritical carbon dioxide, and the metal atom is selected from a group consisting of Ti, Al, Zr, V, and Mg.
    Type: Grant
    Filed: January 24, 2013
    Date of Patent: July 15, 2014
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Hiroyoshi Okuno, Takeshi Iwanaga, Yoshifumi Iida, Chika Hama, Yasunobu Kashima, Shunsuke Nozaki
  • METHOD OF PREPARING SILICA COMPOSITE PARTICLES
    Publication number: 20130331591
    Abstract: Provided is a method of preparing silica composite particles, including treating silica particles, wherein the treating is for treating the silica particles with a metal compound in which a metal atom binds to an organic group via an oxygen atom, in supercritical carbon dioxide, and the metal atom is selected from a group consisting of Ti, Al, Zr, V, and Mg.
    Type: Application
    Filed: January 24, 2013
    Publication date: December 12, 2013
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Hiroyoshi OKUNO, Takeshi IWANAGA, Yoshifumi IIDA, Chika HAMA, Yasunobu KASHIMA, Shunsuke NOZAKI