Patents by Inventor Masahiro YUKIKAWA

Masahiro YUKIKAWA 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: 12287605
    Abstract: A toner includes toner base particles each including: a binder resin, a colorant, and wax; and resin particles on surfaces of the toner base particles. A standard deviation of a distance between the resin particles next to each other on the surfaces of the toner base particles is less than 500 nm.
    Type: Grant
    Filed: May 12, 2021
    Date of Patent: April 29, 2025
    Assignee: Ricoh Technology, Ltd.
    Inventors: Yasuo Kamada, Hiroshi Yamada, Akinori Saitoh, Akio Takei, Toma Takebayashi, Masahiro Yukikawa
  • Publication number: 20250085647
    Abstract: A polyester resin emulsion contains resin particles (S) containing an amorphous polyester resin (A) in which the carboxyl group of a polyester resin obtained by polycondensation of the alcohol component and the carboxylic acid component is neutralized by a basic substance and an aqueous medium where the resin particles (S) are dispersed, wherein the following relationship 1 is satisfied: 0.89 ? B / A ? 2.23 , where A represents an acid value of the amorphous polyester resin (A) and B represents an amount in mmol/g of cation derived from the basic substance.
    Type: Application
    Filed: August 26, 2024
    Publication date: March 13, 2025
    Applicant: Ricoh Company, Ltd.
    Inventors: Masahiro Yukikawa, Junichi Watanabe, Akinori Saitoh, Yuka Mizoguchi
  • Publication number: 20240392064
    Abstract: A polyester resin emulsion contains resin particles(S), each containing a polyester resin (A) obtained by polycondensation of an alcohol component and a carboxylic acid component, and an aqueous medium in which the resin particles(S) are dispersed, wherein the alcohol component contains tri- or tetra-alcohol having a backbone of a linear or branched saturated fatty acid with a carbon number of 4 to 6, and the ratio (OHV/AV) of a hydroxyl value (OHV) of the polyester resin (A) to an acid value (AV) of the polyester resin (A) is from 0.20 to 0.60.
    Type: Application
    Filed: May 21, 2024
    Publication date: November 28, 2024
    Applicant: Ricoh Company, Ltd.
    Inventors: Shinya Nakayama, Junichi Watanabe, Akinori Saitoh, Masahiro Yukikawa, akio Takei
  • Publication number: 20240228770
    Abstract: Resin particles, each include amorphous polyester resins, a crystalline polyester resin, and a release agent. The amorphous polyester resins include (i) an amorphous polyester resin including a sulfonic acid salt group-containing polyester resin and (ii) an amorphous polyester resin different from the amorphous polyester resin including the sulfonic acid salt group-containing polyester resin. The sulfonic acid salt group-containing polyester resin has a solubility parameter of from 10 to 13. Each of the resin particles has a core-shell structure including a core layer and a shell layer. The shell layer includes the (i) amorphous polyester resin including the sulfonic acid salt group-containing polyester resin.
    Type: Application
    Filed: January 3, 2024
    Publication date: July 11, 2024
    Applicant: Ricoh Company, Ltd.
    Inventors: Akinori Saitoh, Junichi Watanabe, Yuka Mizoguchi, Masahiro Yukikawa
  • Publication number: 20240210845
    Abstract: An amorphous polyester resin includes an environmentally friendly component. An environmentally friendly component content of the amorphous polyester resin is 40% by mass or greater and 80% by mass or less. The amorphous polyester resin is a sulfo group-containing amorphous polyester resin. A sulfo group content of the sulfo group-containing amorphous polyester resin is 2 mol % or greater and 10 mol % or less.
    Type: Application
    Filed: December 18, 2023
    Publication date: June 27, 2024
    Applicant: Ricoh Company, Ltd.
    Inventors: Junichi WATANABE, Akinori SAITOH, Masahiro YUKIKAWA, Akio TAKEI, Yuka MIZOGUCHI
  • Publication number: 20240192620
    Abstract: A resin particle contains an amorphous resin, a crystalline resin C containing a biomass-derived resin, and at least one of polyethylene terephthalate or polybutylene terephthalate, wherein the resin particle has a core-shell structure comprising a core resin and a shell resin, the core resin comprises the crystalline resin C, and the proportion of the total mass of the biomass-derived resin, the polyethylene terephthalate, and the polybutylene terephthalate to the resin particle at 100 percent by mass is 30 or more percent by mass.
    Type: Application
    Filed: November 22, 2023
    Publication date: June 13, 2024
    Applicant: Ricoh Company, Ltd.
    Inventors: Yuka Mizoguchi, Akio Takei, Junichi Watanabe, Akinori Saitoh, Masahiro Yukikawa
  • Publication number: 20230305412
    Abstract: A toner includes toner matrix particles containing resin and wax; and an external additive, wherein an average number of voids per toner is 5 or more and 10 or less per toner with a void diameter ? (nm) of voids in the toner matrix particles being 500 ? ? ? 200, as measured based on cross-sectional observation by a scanning electron microscope (SEM).
    Type: Application
    Filed: March 10, 2023
    Publication date: September 28, 2023
    Applicant: Ricoh Company, Ltd
    Inventors: Masahiro YUKIKAWA, Akio Takei, Akinori Saito, Hideto Suzuki
  • Publication number: 20230014605
    Abstract: A toner includes toner base particles and external additives deposited on a surface of the toner base particle. The toner base particle includes an amorphous polyester resin, a crystalline polyester resin, a release agent, and resin particles. An abundance ratio of the crystalline polyester resin in the surface of the toner base particle as observed by TEM is 2.5% or greater but 25% or less. The resin particles are deposited at the surface of the toner base particle as observed by SEM. A ratio of aggregates of the resin particles occupying the surface of the toner base particle is 1% or greater but 70% or less, where R is a major axis of the minimum particle of the resin particles, and the resin particle having a major axis of 3R or greater is determined as the aggregate.
    Type: Application
    Filed: July 6, 2022
    Publication date: January 19, 2023
    Applicant: Ricoh Company, Ltd.
    Inventors: Akinori SAITOH, Akio Takei, Toma Takebayashi, Masahiro Yukikawa, Tomomi Harashima, Hiroshi Yamada
  • Publication number: 20210356877
    Abstract: A toner includes toner base particles each including: a binder resin, a colorant, and wax; and resin particles on surfaces of the toner base particles. A standard deviation of a distance between the resin particles next to each other on the surfaces of the toner base particles is less than 500 nm.
    Type: Application
    Filed: May 12, 2021
    Publication date: November 18, 2021
    Inventors: Yasuo KAMADA, Hiroshi YAMADA, Akinori SAITOH, Akio TAKEI, Toma TAKEBAYASHI, Masahiro YUKIKAWA