Patents by Inventor Ryuuta Yoshida

Ryuuta Yoshida 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).

  • Publication number: 20230147363
    Abstract: A toner includes: toner base particles each containing a binder resin; and resin particles on a surface of each of the toner base particles. A glass transition temperature (Tg) of the toner at the first heating in differential scanning calorimetry (DSC) is 20° C. or higher and 50° C. or lower. A glass transition temperature of a tetrahydrofuran (THF)-insoluble component of the toner at the first heating in DSC is ?40° C. or higher and 10° C. or lower. An average circularity of the toner is 0.970 or more and 0.985 or less. A standard deviation of the average circularity is 0.020 or less.
    Type: Application
    Filed: November 8, 2022
    Publication date: May 11, 2023
    Inventors: Ryuuta YOSHIDA, Akio TAKEI, Ryohei YAMAGUCHI, Toma TAKEBAYASHI
  • Publication number: 20230109578
    Abstract: A toner includes toner base particles each containing a binder resin and a release agent, and resin particles on a surface of each of the toner base particles. A ratio (Iw/Ir) is 0.10 or more and 0.30 or less, where Ir is a peak height of the binder resin and Iw is a peak height of the release agent, as measured through attenuated total reflection (ATR). A standard deviation ? (nm) of distances L (nm) between the resin particles that are adjacent to each other on the surface of each of the toner base particles is 150 nm or more and 500 nm or less.
    Type: Application
    Filed: September 29, 2022
    Publication date: April 6, 2023
    Inventors: Kazumasa TABATA, Akio TAKEI, Hiroshi YAMADA, Toma TAKEBAYASHI, Ryuuta YOSHIDA
  • Publication number: 20220342330
    Abstract: A toner includes toner base particles. Each of the toner base particles includes a binder resin, a colorant, and inorganic filler. An atomic concentration % of Al in the toner base particles as measured by XRF is 0.35 or greater but 0.85 or less. The toner satisfies 0.8<(M1/M2)/(M3/M4)<1.2. M1 is an atomic concentration % of Al in the toner base particles as measured by XPS, M2 is the atomic concentration % of Al in the toner base particles as measured by XRF, and M3 is an atomic concentration % of Al in particles as measured by XPS, and M4 is an atomic concentration % of Al in the particles as measured by XRF. The particles are particles obtained by classifying the toner base particles into 6/5 Dv, and Dv is a volume average particle diameter of the toner base particles.
    Type: Application
    Filed: April 18, 2022
    Publication date: October 27, 2022
    Applicant: Ricoh Company, Ltd.
    Inventors: Ryohei YAMAGUCHI, Ryuuta Yoshida, Yoshiyasu Adachi, Kazumasa Tabata, Akira Tanaka
  • Publication number: 20220137525
    Abstract: The present disclosure provides a toner having excellent low-temperature fixing, heat-resistant-storage property, cleaning performance, and filming resistance. A toner containing toner base particles having a crystalline polyester resin and an amorphous polyester resin includes a plurality of organic particles disposed at least partially embedded in a surface of the toner base particles. A percentage of the crystalline polyester resin occupying the surface of the toner base particles is 4% to 20%, a volume average particle size of the organic particles is 10 nm to 40 nm, and a standard deviation of a distance between adjacent particles of the organic particles that are not in contact is 500 nm or less.
    Type: Application
    Filed: November 2, 2021
    Publication date: May 5, 2022
    Applicant: Ricoh Company, Ltd.
    Inventors: Ryuuta Yoshida, Toma Takebayashi, Akio Takei, Yasuo Kamada
  • Patent number: 10073366
    Abstract: A toner is provided. The toner includes an amorphous resin, a crystalline resin dispersed in the amorphous resin, and a release agent. The toner satisfies the following inequality: B/A<0.8 where A represents a perimeter of the crystalline resin and B represents a length of a part of the perimeter A of the crystalline resin at which the crystalline resin is in contact with the amorphous resin, A and B being measured from a cross-sectional image of the toner observed with transmission electron microscope.
    Type: Grant
    Filed: June 14, 2017
    Date of Patent: September 11, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Kohsuke Nagata, Ryuuta Yoshida, Shinya Nakayama, Tsuyoshi Sugimoto, Akinori Saitoh, Hideyuki Santo, Suzuka Karato, Koh Ohnuma, Takahiro Kadota, Shinsuke Nagai, Akihiro Takeyama
  • Publication number: 20170363980
    Abstract: A toner is provided. The toner includes an amorphous resin, a crystalline resin dispersed in the amorphous resin, and a release agent. The toner satisfies the following inequality: B/A<0.8 where A represents a perimeter of the crystalline resin and B represents a length of a part of the perimeter A of the crystalline resin at which the crystalline resin is in contact with the amorphous resin, A and B being measured from a cross-sectional image of the toner observed with transmission electron microscope.
    Type: Application
    Filed: June 14, 2017
    Publication date: December 21, 2017
    Inventors: Kohsuke NAGATA, Ryuuta YOSHIDA, Shinya NAKAYAMA, Tsuyoshi SUGIMOTO, Akinori SAITOH, Hideyuki SANTO, Suzuka KARATO, Koh OHNUMA, Takahiro KADOTA, Shinsuke NAGAI, Akihiro TAKEYAMA
  • Patent number: 9201326
    Abstract: A toner including: a binder resin containing a non-crystalline resin and a crystalline resin; a colorant; and, a releasing agent, wherein the releasing agent has a melting point of 55° C. to 80° C., and wherein the toner satisfies the following Expressions 1 and 2: (Expression 1): 20,000 Pa·s?G1?50,000 Pa·s; and (Expression 2): (G4/G2)/(G3/G1) 1.00, where G1 is a storage modulus, G2 is a loss modulus, G3 is a storage modulus and G4 is a loss modulus, and the storage modulus G1 and the loss modulus G2 are measured at 80° C. when the toner is heated from 70° C. to 150° C. and the storage modulus G3 and the loss modulus G4 are measured at 80° C. when the toner heated to 150° C. is cooled to 70° C.
    Type: Grant
    Filed: December 28, 2012
    Date of Patent: December 1, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Ryuuta Yoshida, Takahiro Honda, Junichi Awamura, Osamu Uchinokura, Masaki Watanabe, Daisuke Inoue, Tomoki Murayama, Mamoru Hozumi
  • Patent number: 8999618
    Abstract: A toner set, including: at least one chromatic toner containing a colorant; and a transparent toner containing no colorant, wherein the chromatic toner and the transparent toner each include a releasing agent and a binder resin, and wherein an amount of a tetrahydrofuran insoluble matter in the transparent toner is smaller than an amount of a tetrahydrofuran insoluble matter in the chromatic toner.
    Type: Grant
    Filed: May 20, 2013
    Date of Patent: April 7, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Ryuuta Yoshida, Satoshi Ogawa, Masaki Watanabe, Hyo Shu, Naohiro Watanabe
  • Patent number: 8778588
    Abstract: To provide a toner, which contains a binder resin, a colorant, and a releasing agent, wherein the binder resin contains a low molecular weight resin component, where the low molecular weight resin component has a resin softening coefficient (A), represented by the following formula (1), satisfying A>0.165, and has storage elastic modulus (dyne/cm2) G?(Tfb) satisfying G?(Tfb)?1×104 where Tfb is a flow onset temperature (° C.) of the low molecular weight resin component as measured by a capillary rheometer: A=|[(r1)?ln G?(r2)]/(T1?T2)|??Formula (1) (where T1 is temperature (° C.) at which storage elastic modulus G?(r1) is 1×105 (dyne/cm2) and T2 is temperature (° C.) at which storage elastic modulus G?(r2) is 1×103 (dyne/cm2) as measured by means of a viscoelasticity measuring device with measuring frequency of 1 Hz, and measuring distortion of 1 deg; and | | represents an absolute value.).
    Type: Grant
    Filed: October 12, 2011
    Date of Patent: July 15, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Teruki Kusahara, Junichi Awamura, Tsuyoshi Sugimoto, Hyo Shu, Tomomi Suzuki, Osamu Uchinokura, Takahiro Honda, Satoshi Kojima, Satoshi Ogawa, Daisuke Inoue, Koshi Sato, Daisuke Ito, Ryuuta Yoshida, Syouko Satoh
  • Publication number: 20130316280
    Abstract: A toner set, including: at least one chromatic toner containing a colorant; and a transparent toner containing no colorant, wherein the chromatic toner and the transparent toner each include a releasing agent and a binder resin, and wherein an amount of a tetrahydrofuran insoluble matter in the transparent toner is smaller than an amount of a tetrahydrofuran insoluble matter in the chromatic toner.
    Type: Application
    Filed: May 20, 2013
    Publication date: November 28, 2013
    Inventors: Ryuuta YOSHIDA, Satoshi OGAWA, Masaki WATANABE, Hyo SHU, Naohiro WATANABE
  • Publication number: 20130196260
    Abstract: A toner including: a binder resin containing a non-crystalline resin and a crystalline resin; a colorant; and, a releasing agent, wherein the releasing agent has a melting point of 55° C. to 80° C., and wherein the toner satisfies the following Expressions 1 and 2: (Expression 1): 20,000 Pa·s?G1?50,000 Pa·s; and (Expression 2): (G4/G2)/(G3/G1) 1.00, where G1 is a storage modulus, G2 is a loss modulus, G3 is a storage modulus and G4 is a loss modulus, and the storage modulus G1 and the loss modulus G2 are measured at 80° C. when the toner is heated from 70° C. to 150° C. and the storage modulus G3 and the loss modulus G4 are measured at 80° C. when the toner heated to 150° C. is cooled to 70° C.
    Type: Application
    Filed: December 28, 2012
    Publication date: August 1, 2013
    Inventors: Ryuuta YOSHIDA, Takahiro HONDA, Junichi AWAMURA, Osamu UCHINOKURA, Masaki WATANABE, Daisuke INOUE, Tomoki MURAYAMA, Mamoru HOZUMI
  • Publication number: 20130022371
    Abstract: To provide a toner, which contains a binder resin, a colorant, and a releasing agent, wherein the binder resin contains a low molecular weight resin component, where the low molecular weight resin component has a resin softening coefficient (A), represented by the following formula (1), satisfying A>0.165, and has storage elastic modulus (dyne/cm2) G?(Tfb) satisfying G?(Tfb)?1×104 where Tfb is a flow onset temperature (° C.) of the low molecular weight resin component as measured by a capillary rheometer: A=|[ln G?(r1)?ln G?(r2)]/(T1?T2)|??Formula (1) (where T1 is temperature (° C.) at which storage elastic modulus G?(r1) is 1×105 (dyne/cm2) and T2 is temperature (° C.) at which storage elastic modulus G?(r2) is 1×103 (dyne/cm2) as measured by means of a viscoelasticity measuring device with measuring frequency of 1 Hz, and measuring distortion of 1 deg; and ? represents an absolute value.
    Type: Application
    Filed: October 12, 2011
    Publication date: January 24, 2013
    Applicant: Ricoh Company, Ltd.
    Inventors: Teruki Kusahara, Junichi Awamura, Tsuyoshi Sugimoto, Hyo Shu, Tomomi Suzuki, Osamu Uchinokura, Takahiro Honda, Satoshi Kojima, Satoshi Ogawa, Daisuke Inoue, Koshi Sato, Daisuke Ito, Ryuuta Yoshida, Syouko Satoh