Patents by Inventor Yuka KAWAMOTO

Yuka KAWAMOTO 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: 10935900
    Abstract: A toner for developing an electrostatic charge image includes toner particles containing a binder resin; and an external additive containing silica particles, in which a coefficient of variation of a Si content is determined by determining the Si content in 0.5 ?m×0.5 ?m square regions in a surface of each of the toner particles after performing a process of dispersing the toner in water and drying the dispersed toner, and an amount of change between this coefficient of variation of the Si content and a coefficient of variation of a Si content before the process ((coefficient of variation of Si content after process)?(coefficient of variation of Si content before process)) is 0.05 or more and 0.60 or less.
    Type: Grant
    Filed: August 6, 2019
    Date of Patent: March 2, 2021
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Daisuke Ishizuka, Narumasa Sato, Yuka Kawamoto, Erina Saito, Norimasa Ozora, Kotaro Yoshihara, Noriyuki Mizutani
  • Publication number: 20200292950
    Abstract: A toner for developing an electrostatic charge image includes toner particles containing a binder resin; and an external additive containing silica particles, in which a coefficient of variation of a Si content is determined by determining the Si content in 0.5 ?m×0.5 ?m square regions in a surface of each of the toner particles after performing a process of dispersing the toner in water and drying the dispersed toner, and an amount of change between this coefficient of variation of the Si content and a coefficient of variation of a Si content before the process ((coefficient of variation of Si content after process)?(coefficient of variation of Si content before process)) is 0.05 or more and 0.60 or less.
    Type: Application
    Filed: August 6, 2019
    Publication date: September 17, 2020
    Applicant: FUJI XEROX Co., Ltd.
    Inventors: Daisuke ISHIZUKA, Narumasa Sato, Yuka Kawamoto, Erina Saito, Norimasa Ozora, Kotaro Yoshihara, Noriyuki Mizutani
  • Patent number: 10578989
    Abstract: An electrostatic charge image developer includes: a toner that includes toner particles which contain a polyester resin and a styrene (meth)acrylic resin and form a sea-island structure which includes a sea portion containing the polyester resin and an island portion containing the styrene (meth)acrylic resin on a surface of the toner particle, and has an exposure rate of the styrene (meth)acrylic resin in a range of from about 5 atom % to about 20 atom %; and an external additive, and a carrier whose fluidity and bulk density under environment of a temperature of 25° C. and a humidity of 50% satisfy Expression: 65.0?fluidity×bulk density?72.5.
    Type: Grant
    Filed: February 9, 2018
    Date of Patent: March 3, 2020
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Kotaro Yoshihara, Daisuke Ishizuka, Narumasa Sato, Yuka Kawamoto, Erina Saito, Takahisa Tatekawa, Noriyuki Mizutani
  • Patent number: 10520841
    Abstract: An electrostatic image developing toner includes a toner particle and an external additive. The toner particle contains a binder resin and a release agent that includes a hydrocarbon wax. The binder resin includes a vinyl resin and a hybrid resin in which an amorphous resin unit other than polyester resins and a crystalline polyester resin unit are chemically bound together. The toner particle has hybrid resin domains and release agent domains. An average distance Lhyb from the surface of the toner particle to the centers of the hybrid resin domains and an average distance Lwax from the surface of the toner particle to the centers of the release agent domains satisfy Lwax<Lhyb.
    Type: Grant
    Filed: September 5, 2018
    Date of Patent: December 31, 2019
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Narumasa Sato, Erina Saito, Yuka Kawamoto, Noriyuki Mizutani, Kotaro Yoshihara, Daisuke Ishizuka
  • Publication number: 20190294063
    Abstract: An electrostatic image developing toner includes a toner particle and an external additive. The toner particle contains a binder resin and a release agent that includes a hydrocarbon wax. The binder resin includes a vinyl resin and a hybrid resin in which an amorphous resin unit other than polyester resins and a crystalline polyester resin unit are chemically bound together. The toner particle has hybrid resin domains and release agent domains. An average distance Lhyb from the surface of the toner particle to the centers of the hybrid resin domains and an average distance Lwax from the surface of the toner particle to the centers of the release agent domains satisfy Lwax<Lhyb.
    Type: Application
    Filed: September 5, 2018
    Publication date: September 26, 2019
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Narumasa SATO, Erina SAITO, Yuka KAWAMOTO, Noriyuki MIZUTANI, Kotaro YOSHIHARA, Daisuke ISHIZUKA
  • Publication number: 20180275543
    Abstract: An electrostatic charge image developer includes: a toner that includes toner particles which contain a polyester resin and a styrene (meth)acrylic resin and form a sea-island structure which includes a sea portion containing the polyester resin and an island portion containing the styrene (meth)acrylic resin on a surface of the toner particle, and has an exposure rate of the styrene (meth)acrylic resin in a range of from about 5 atom % to about 20 atom %; and an external additive, and a carrier whose fluidity and bulk density under environment of a temperature of 25° C. and a humidity of 50% satisfy Expression: 65.0?fluidity×bulk density?72.5.
    Type: Application
    Filed: February 9, 2018
    Publication date: September 27, 2018
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Kotaro YOSHIHARA, Daisuke ISHIZUKA, Narumasa SATO, Yuka KAWAMOTO, Erina SAITO, Takahisa TATEKAWA, Noriyuki MIZUTANI
  • Patent number: 9715185
    Abstract: An electrostatic-image developing toner includes a toner particle including a polyester resin and a styrene-(meth)acrylic resin, and an external additive including a poly[alkyl (meth)acrylate] particle. The amount of the poly[alkyl (meth)acrylate] particles is about 0.05 parts by mass or more and about 1.0 parts by mass or less relative to 100 parts by mass of the toner particle. The ratio D50P/D50T of the number-average diameter D50P of the poly[alkyl (meth)acrylate] particles to the number-average diameter D50T of the toner particles satisfies 0.03?D50P/D50T?0.15. The proportion of the styrene-(meth)acrylic resin in a resin component deposited on the surface of the toner particle is about 5 atom % or more and about 30 atom % or less as determined by X-ray photoelectron spectroscopy (XPS).
    Type: Grant
    Filed: November 6, 2015
    Date of Patent: July 25, 2017
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Yuka Kawamoto, Kotaro Yoshihara, Daisuke Ishizuka, Asafumi Fujita, Narumasa Sato, Erina Saito
  • Patent number: 9612542
    Abstract: An electrostatic charge image developing toner includes a binder resin containing a polyester resin, a release agent, a colorant, and an aromatic aldehyde compound, the content of which exceeds 100 ppm and is equal to or smaller than 1200 ppm.
    Type: Grant
    Filed: October 6, 2014
    Date of Patent: April 4, 2017
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Yuki Takamiya, Yuka Kawamoto, Daisuke Ishizuka, Noriyuki Mizutani
  • Patent number: 9575428
    Abstract: An electrostatic-image developing toner contains toner particles. The toner particles contain a binder resin, a release agent, and a styrene-(meth)acrylic resin. The binder resin contains a polyester resin. About 70% or more of all release agent is present within about 800 nm from surfaces of the toner particles. The styrene-(meth)acrylic resin is present in an amount of about 5 to about 25 atomic percent of the resin components in the surfaces of the toner particles as determined by X-ray photoelectron spectroscopy (XPS).
    Type: Grant
    Filed: October 29, 2015
    Date of Patent: February 21, 2017
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Narumasa Sato, Kotaro Yoshihara, Daisuke Ishizuka, Asafumi Fujita, Erina Saito, Yuka Kawamoto, Noriyuki Mizutani
  • Publication number: 20160357120
    Abstract: An electrostatic-image developing toner includes a toner particle including a polyester resin and a styrene-(meth)acrylic resin, and an external additive including a poly[alkyl (meth)acrylate] particle. The amount of the poly[alkyl (meth)acrylate] particles is about 0.05 parts by mass or more and about 1.0 parts by mass or less relative to 100 parts by mass of the toner particle. The ratio D50P/D50T of the number-average diameter D50P of the poly[alkyl (meth)acrylate] particles to the number-average diameter D50T of the toner particles satisfies 0.03?D50P/D50T?0.15. The proportion of the styrene-(meth)acrylic resin in a resin component deposited on the surface of the toner particle is about 5 atom % or more and about 30 atom % or less as determined by X-ray photoelectron spectroscopy (XPS).
    Type: Application
    Filed: November 6, 2015
    Publication date: December 8, 2016
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Yuka KAWAMOTO, Kotaro YOSHIHARA, Daisuke ISHIZUKA, Asafumi FUJITA, Narumasa SATO, Erina SAITO
  • Publication number: 20160349643
    Abstract: An electrostatic-image developing toner includes a toner particle that includes a binder resin including an amorphous polyester resin and a crystalline polyester resin and that includes a styrene-alkyl(meth)acrylate copolymer. The glass transition temperature Tg(A) of the styrene-alkyl(meth)acrylate copolymer and the glass transition temperature Tg(B) of the amorphous polyester resin satisfy Relational expression (1): Tg(B)?10?Tg(A)?Tg(B)+2.5.
    Type: Application
    Filed: November 12, 2015
    Publication date: December 1, 2016
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Erina SAITO, Kotaro YOSHIHARA, Daisuke ISHIZUKA, Yuka KAWAMOTO
  • Publication number: 20160342101
    Abstract: An electrostatic-image developing toner contains toner particles. The toner particles contain a binder resin, a release agent, and a styrene-(meth)acrylic resin. The binder resin contains a polyester resin. About 70% or more of all release agent is present within about 800 nm from surfaces of the toner particles. The styrene-(meth)acrylic resin is present in an amount of about 5 to about 25 atomic percent of the resin components in the surfaces of the toner particles as determined by X-ray photoelectron spectroscopy (XPS).
    Type: Application
    Filed: October 29, 2015
    Publication date: November 24, 2016
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Narumasa SATO, Kotaro YOSHIHARA, Daisuke ISHIZUKA, Asafumi FUJITA, Erina SAITO, Yuka KAWAMOTO, Noriyuki MIZUTANI
  • Patent number: 9482972
    Abstract: An electrostatic charge image developing toner includes toner particles including a binder resin that contains a copolymer formed by copolymerizing at least an aromatic vinyl monomer and an aliphatic unsaturated alkyl carboxylate ester, wherein a weight ratio of component M1 of the aromatic vinyl monomer and component M2 of the aliphatic unsaturated alkyl carboxylate ester in the copolymer satisfies the following expression (1), and a weight ratio of volatile component m1 of the aromatic vinyl monomer and volatile component m2 of the aliphatic unsaturated alkyl carboxylate ester, as measured by a headspace method, satisfies the following expression (2): 0.10?MW2/(MW1+MW2)?0.30??Expression (1) 0.70?mw2/(mw1+mw2)?0.98??Expression (2) wherein MW1 represents the weight of M1, MW2 represents the weight of M2, mw1 represents the weight of m1, and mw2 represents the weight of m2.
    Type: Grant
    Filed: February 26, 2015
    Date of Patent: November 1, 2016
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Daisuke Ishizuka, Yuki Takamiya, Yuka Kawamoto, Noriyuki Mizutani
  • Publication number: 20160313660
    Abstract: An electrostatic charge image developing toner includes toner particles containing a binder resin having a polyester resin and a styrene-(meth)acrylic acid alkyl copolymer resin, a release agent having a hydrocarbon release agent, and an oligomer which includes a styrene structure and whose content is in a range of 1% by weight to 6% by weight with respect to toner particles.
    Type: Application
    Filed: June 30, 2016
    Publication date: October 27, 2016
    Inventors: Erina SAITO, Noriyuki MIZUTANI, Daisuke ISHIZUKA, Kotaro YOSHIHARA, Yuki TAKAMIYA, Narumasa SATO, Yuka KAWAMOTO
  • Publication number: 20160070187
    Abstract: An electrostatic charge image developing toner includes toner particles containing a binder resin that contains a polyester resin having an ethylenically unsaturated double bond, a di- or higher valent metal ion, and (meth)acrylic acid alkyl ester that has an alkyl chain having 1 to 10 carbon atoms, wherein a content of the (meth)acrylic acid alkyl ester is in a range of 50 ppm to 500 ppm with respect to toner particles.
    Type: Application
    Filed: January 22, 2015
    Publication date: March 10, 2016
    Inventors: Yuka KAWAMOTO, Daisuke ISHIZUKA, Yuki TAKAMIYA, Noriyuki MIZUTANI
  • Publication number: 20160070186
    Abstract: An electrostatic charge image developing toner includes toner particles containing a binder resin having a polyester resin and a styrene-(meth)acrylic acid alkyl copolymer resin, a release agent having a hydrocarbon release agent, and an oligomer which includes a styrene structure and whose content is in a range of 1% by weight to 6% by weight with respect to toner particles.
    Type: Application
    Filed: February 2, 2015
    Publication date: March 10, 2016
    Inventors: Erina SAITO, Noriyuki MIZUTANI, Daisuke ISHIZUKA, Kotaro YOSHIHARA, Yuki TAKAMIYA, Narumasa SATO, Yuka KAWAMOTO
  • Publication number: 20160041485
    Abstract: An electrostatic charge image developing toner includes toner particles including a binder resin that contains a copolymer formed by copolymerizing at least an aromatic vinyl monomer and an aliphatic unsaturated alkyl carboxylate ester, wherein a weight ratio of component M1 of the aromatic vinyl monomer and component M2 of the aliphatic unsaturated alkyl carboxylate ester in the copolymer satisfies the following expression (1), and a weight ratio of volatile component m1 of the aromatic vinyl monomer and volatile component m2 of the aliphatic unsaturated alkyl carboxylate ester, as measured by a headspace method, satisfies the following expression (2): 0.10?MW2/(MW1+MW2)?0.30??Expression (1) 0.70?mw2/(mw1+mw2)?0.98??Expression (2) wherein MW1 represents the weight of M1, MW2 represents the weight of M2, mw1 represents the weight of m1, and mw2 represents the weight of m2.
    Type: Application
    Filed: February 26, 2015
    Publication date: February 11, 2016
    Inventors: Daisuke ISHIZUKA, Yuki TAKAMIYA, Yuka KAWAMOTO, Noriyuki MIZUTANI
  • Publication number: 20150370187
    Abstract: An electrostatic charge image developing toner includes a binder resin containing a polyester resin, a release agent, a colorant, and an aromatic aldehyde compound, the content of which exceeds 100 ppm and is equal to or smaller than 1200 ppm.
    Type: Application
    Filed: October 6, 2014
    Publication date: December 24, 2015
    Inventors: Yuki TAKAMIYA, Yuka KAWAMOTO, Daisuke ISHIZUKA, Noriyuki MIZUTANI