Patents by Inventor Mayuka Chiba

Mayuka Chiba 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: 11099494
    Abstract: Provided is a magenta toner which is more excellent in durability in a high temperature and high humidity environment than conventional ones. The magenta toner comprises a binder resin, a magenta colorant, a release agent and an external additive. The release agent has a maximum endothermic peak in a range of from 70° C. to 80° C. during temperature increase, in a DSC curve measured by a differential scanning calorimeter. Needle-shaped oxide fine particles having an average long diameter of from 30 nm to 500 nm and an aspect ratio of from 4 to 20 are contained therein. Zinc stearate particles having a number average primary particle diameter of from 0.1 ?m to 5 ?m are contained at an amount of from 0.01 part by mass to 0.5 part by mass with respect to 100 parts by mass of the colored resin particles, as the external additives.
    Type: Grant
    Filed: March 26, 2018
    Date of Patent: August 24, 2021
    Assignee: ZEON CORPORATION
    Inventors: Mayuka Chiba, Hiroshi Nakatani
  • Publication number: 20200285165
    Abstract: Provided is a magenta toner which is more excellent in durability in a high temperature and high humidity environment than conventional ones. The magenta toner comprises a binder resin, a magenta colorant, a release agent and an external additive, wherein a compound A, a compound B and a compound C each having a specific chemical structure are contained as the magenta colorant, and wherein the release agent has a maximum endothermic peak in a range of from 70° C. to 80° C. during temperature increase, in a DSC curve measured by a differential scanning calorimeter.
    Type: Application
    Filed: March 26, 2018
    Publication date: September 10, 2020
    Applicant: ZEON CORPORATION
    Inventors: Mayuka Chiba, Hiroshi Nakatani