Patents by Inventor Yuya HIROKAWA

Yuya HIROKAWA 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: 11904600
    Abstract: A printing method includes discharging ink to a substrate, heating a non-ink-discharged side of the substrate at T1, and heating an ink-discharged side of the substrate at T2, wherein the ink contains an organic solvent A (boiling point lower than 250 degrees C.), an organic solvent B (boiling point of 250 degrees C.), and a resin, where 0 degrees C. C?T2?T1?90 degrees C. is satisfied, the proportion (organic solvent A/ink) is 30 percent by mass or less, the proportion (organic solvent B/ink) is 1 to 3 percent by mass, the proportion (resin/ink) is 5 to 15 percent by mass, the ink has a viscosity of 8.0 to 11.0 mPa-s at 25 degrees C. and 5.5 to 11.0 mPa-s at 36 degrees C., and a 2.5 ?L ink droplet discharged to the substrate shrinks to 0.1 ?L within 10.0 seconds at 25 degrees C.
    Type: Grant
    Filed: March 29, 2022
    Date of Patent: February 20, 2024
    Assignee: RICOH COMPANY, LTD.
    Inventors: Naoto Shimura, Yuya Hirokawa, Yuusuke Koizuka, Takayuki Shimizu, Itsuro Sasaki, Shunsuke Horie, Nozomi Terai, Kenta Hagiwara
  • Publication number: 20240034851
    Abstract: Provided is a method of manufacturing a molded body. The method includes: producing a foam sheet having a crystallinity degree A of 7.5% or less by using a composition containing polylactic acid comprising 98 mol % or more of any one among a D-isomer of lactic acid and an L-isomer of lactic acid as a constituent monomer unit; and molding the foam sheet with heat to produce a molded body, and a difference (B?A) between the crystallinity degree A of the foam sheet and the crystallinity degree B of the molded body is 20.0% or more and 40.0% or less.
    Type: Application
    Filed: July 21, 2023
    Publication date: February 1, 2024
    Applicant: Ricoh Company, Ltd.
    Inventors: Yuya Hirokawa, Ryo Miyakoshi, Satoshi Ogawa, Yoshimitsu Kumai, Risa Tamura
  • Publication number: 20230331000
    Abstract: A printing method involves applying a processing fluid containing a multivalent metal salt to a print medium, to form a processing fluid layer; applying a white ink containing a white coloring material and water to form a white ink layer; and applying a non-white ink containing a non-white coloring material and water to the white ink layer, after securing a time interval of 0.5 seconds or longer after the white ink is applied without drying with a drying unit after the white ink is applied. The print medium has a Cobb water absorption of 20 g/m2 or greater but 75 g/m2 or less when contacted with water for 120 seconds, where the Cobb water absorption is stipulated by JIS-P8140.
    Type: Application
    Filed: August 20, 2021
    Publication date: October 19, 2023
    Applicant: Ricoh Company, Ltd.
    Inventors: Sei Yamamoto, Tomohiro Nakagawa, Kazuhiko Umemura, Yuya Hirokawa, Hiroki Hagiwara, Takuya Saiga
  • Publication number: 20230220226
    Abstract: An ink set includes a non-white ink and a white ink. The non-white ink contains water, a coloring material, an organic solvent, and an acetylene glycol compound. The white ink contains water, a coloring material, an organic solvent, and a compound represented by General formula (1) below where R represents a hydrogen atom or a methyl group, n1 and n2 represent integers of from 1 through 7, k represents an integer of from 0 through 5, and m represents an integer of from 1 through 20.
    Type: Application
    Filed: April 27, 2021
    Publication date: July 13, 2023
    Applicant: Ricoh Company, Ltd.
    Inventors: Hiroki HAGIWARA, Tomohiro Nakagawa, Kazuhiko Umemura, Masayuki Koyano, Sei Yamamoto, Yuya Hirokawa, Takuya Saiga
  • Patent number: 11639064
    Abstract: An image forming method includes discharging ink containing water, a coloring material, a polymerization initiator, and a polymerizable compound to a recording medium by a line head to obtain an image, exposing the image to active energy radiation, applying a processing fluid to the image, and drying the image with heat, wherein the time interval between when the ink is discharged in the discharging from the line head to the recording medium passing under a bottom portion of the line head and when the recording medium is exposed to the active energy radiation in the exposing is from 0.5 to 15 seconds.
    Type: Grant
    Filed: October 20, 2021
    Date of Patent: May 2, 2023
    Assignee: RICOH COMPANY, LTD.
    Inventors: Takuya Saiga, Hidetoshi Fujii, Shigeyuki Harada, Yuya Hirokawa
  • Publication number: 20230051878
    Abstract: Provided is an image printing method including a first processing fluid applying step of applying a first processing fluid containing a multivalent metal salt to a predetermined region of a print medium, and a second processing fluid applying step of applying a second processing fluid containing a resin emulsion containing an anionic functional group to the predetermined region of the print medium to which the first processing fluid is applied and any other region of the print medium to which the first processing fluid is not applied.
    Type: Application
    Filed: July 28, 2022
    Publication date: February 16, 2023
    Inventors: Sei YAMAMOTO, Kazuhiko UMEMURA, Yuya HIROKAWA, Hiroki HAGIWARA, Takuya SAIGA, Risa TAMURA
  • Publication number: 20230032881
    Abstract: An active energy ray polymerization initiator has a structure of Chemical Formula (1) or (2), L1 represents Chemical Formula (I), L2 represents Chemical Formula (II), one of L3 and L4 and one of L5 and L6 represent the same group as L1, the rest of L3 and L4 and one of L5 and L6 represent the same group as L2, Link 2 represents a single bond, —O—, —CO—, —SO2—, —C(CF3)2—, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an aromatic group having 6 to 15 carbon atoms, Z represents a tertiary amine. R represents a hydrocarbon group having one to three carbon atoms or methoxy group, n represents 0 or an integer of from 1 to 3, Link 1 represents —(CH2)x—(OC2H4)y—, where x represents an integer of from 2 to 12 and y represents 0 or an integer of from 1 to 11.
    Type: Application
    Filed: July 1, 2022
    Publication date: February 2, 2023
    Applicant: Ricoh Company, Ltd.
    Inventors: Shigeyuki HARADA, Yuya Hirokawa
  • Publication number: 20230012907
    Abstract: An image forming method includes a processing fluid applying step and an ink applying step. The processing fluid applying step involves applying a processing fluid containing a multivalent metal salt, a resin TA, a resin TB different from the resin TA, and a silicone-based surfactant to a non-permeating base material by an inkjet method, where the processing fluid is free of an organic solvent having a boiling point of 200° C. or higher at normal pressure. The ink applying step involves applying an ink containing a coloring material, an organic solvent, and a resin onto the processing fluid.
    Type: Application
    Filed: July 1, 2022
    Publication date: January 19, 2023
    Applicant: Ricoh Company, Ltd.
    Inventors: Tatsuya Takarada, Yuusuke Koizuka, Naoto Shimura, Nozomi Terai, Yuya Hirokawa
  • Patent number: 11548294
    Abstract: A method of printing includes applying a processing fluid to a substrate and inkjet discharging a white ink to the substrate onto which the processing fluid has been applied, wherein the processing fluid contains a tri-valent metal salt, a nonionic urethane resin, and water and the white ink contains a white pigment, a resin, and water.
    Type: Grant
    Filed: October 10, 2021
    Date of Patent: January 10, 2023
    Assignee: RICOH COMPANY, LTD.
    Inventors: Takuya Saiga, Sei Yamamoto, Kazuhiko Umemura, Yuya Hirokawa, Hiroki Hagiwara
  • Publication number: 20220324241
    Abstract: A printing method includes discharging ink to a substrate, heating a non-ink-discharged side of the substrate at T1, and heating an ink-discharged side of the substrate at T2, wherein the ink contains an organic solvent A (boiling point lower than 250 degrees C.), an organic solvent B (boiling point of 250 degrees C.), and a resin, where 0 degrees C. C?T2?T1?90 degrees C. is satisfied, the proportion (organic solvent A/ink) is 30 percent by mass or less, the proportion (organic solvent B/ink) is 1 to 3 percent by mass, the proportion (resin/ink) is 5 to 15 percent by mass, the ink has a viscosity of 8.0 to 11.0 mPa-s at 25 degrees C. and 5.5 to 11.0 mPa-s at 36 degrees C., and a 2.5 ?L ink droplet discharged to the substrate shrinks to 0.1 ?L within 10.0 seconds at 25 degrees C.
    Type: Application
    Filed: March 29, 2022
    Publication date: October 13, 2022
    Inventors: Naoto SHIMURA, Yuya HIROKAWA, Yuusuke KOIZUKA, Takayuki SHIMIZU, Itsuro SASAKI, Shunsuke HORIE, Nozomi TERAI, Kenta HAGIWARA
  • Publication number: 20220177718
    Abstract: An ink contains organic solvents containing 1,2-propane diol and 1,2-hexane diol, a pigment, water, and a polyoxyethylene ether compound.
    Type: Application
    Filed: December 6, 2021
    Publication date: June 9, 2022
    Applicant: Ricoh Company, Ltd.
    Inventors: Kazuhiko Umemura, Sei Yamamoto, Yuya Hirokawa, Hiroki Hagiwara, Takuya Saiga, Tomohiro Nakagawa
  • Publication number: 20220169034
    Abstract: Provided is a processing fluid including nonionic acrylic resin particles, and a polyvalent metal salt. A volume average particle diameter of the nonionic acrylic resin particles is 100 nm or greater but 300 nm or less. A proportion of the nonionic acrylic resin particles in the processing fluid is greater than 2.0% by mass. An average reflectance of the processing fluid to light having a wavelength of 400 nm or greater but 700 nm or less is 70% or greater.
    Type: Application
    Filed: November 22, 2021
    Publication date: June 2, 2022
    Applicant: Ricoh Company, Ltd.
    Inventors: Hiroki HAGIWARA, Tomohiro Nakagawa, Sei Yamamoto, Kazuhiko Umemura, Yuya Hirokawa, Takuya Saiga, Risa Tamura
  • Publication number: 20220126605
    Abstract: An image forming method includes discharging ink containing water, a coloring material, a polymerization initiator, and a polymerizable compound to a recording medium by a line head to obtain an image, exposing the image to active energy radiation, applying a processing fluid to the image, and drying the image with heat, wherein the time interval between when the ink is discharged in the discharging from the line head to the recording medium passing under a bottom portion of the line head and when the recording medium is exposed to the active energy radiation in the exposing is from 0.5 to 15 seconds.
    Type: Application
    Filed: October 20, 2021
    Publication date: April 28, 2022
    Applicant: Ricoh Company, Ltd.
    Inventors: Takuya Saiga, Hidetoshi Fujii, Shigeyuki Harada, Yuya Hirokawa
  • Publication number: 20220118774
    Abstract: A method of printing includes applying a processing fluid to a substrate and inkjet discharging a white ink to the substrate onto which the processing fluid has been applied, wherein the processing fluid contains a tri-valent metal salt, a nonionic urethane resin, and water and the white ink contains a white pigment, a resin, and water.
    Type: Application
    Filed: October 10, 2021
    Publication date: April 21, 2022
    Applicant: Ricoh Company, Ltd.
    Inventors: Takuya SAIGA, Sei Yamamoto, Kazuhiko Umemura, Yuya Hirokawa, Hiroki Hagiwara
  • Patent number: 11267255
    Abstract: An image forming method is provided. The method includes the steps of (a) applying an ink to a recording medium to form an image and (b) applying a pressure to the recording medium to which the ink has been applied. The ink comprises water, an organic solvent, and a colorant. When the ink is formed into an ink film, a maximum value of logarithmic damping ratio of the ink film is 1.50 or less and a time elapsed until the logarithmic damping ratio reaches the maximum value is 3,800 seconds or less, when measured by a rigid-body pendulum test at 60° C.
    Type: Grant
    Filed: April 17, 2020
    Date of Patent: March 8, 2022
    Assignee: Ricoh Company, Ltd.
    Inventors: Shun Saito, Hiromi Sakaguchi, Takashi Tamai, Sayuri Kojima, Yuya Hirokawa
  • Publication number: 20220056298
    Abstract: Provided is a processing fluid including: water; a flocculant; and a urethane resin. A dry film formed of the processing fluid and having an average thickness of 500 micrometers has a tensile strength of 3.5 MPa or greater and a breaking elongation of 80% or greater.
    Type: Application
    Filed: July 27, 2021
    Publication date: February 24, 2022
    Applicant: Ricoh Company, Ltd.
    Inventors: Kazuhiko Umemura, Tomohiro Nakagawa, Hiroki Hagiwara, Sei Yamamoto, Masayuki Koyano, Yuya Hirokawa, Takuya Saiga
  • Publication number: 20220056299
    Abstract: A printing method includes: a processing fluid applying step of applying a processing fluid containing silica and a multivalent metal salt to a print medium; and an ink applying step of applying an ink containing a coloring material and water to the print medium. The print medium has a Cobb water absorption of 20 g/m2 or greater but 75 g/m2 or less when contacted with water for 120 seconds. The Cobb water absorption is stipulated by JIS-P8140.
    Type: Application
    Filed: July 28, 2021
    Publication date: February 24, 2022
    Applicant: Ricoh Company, Ltd.
    Inventors: Sei Yamamoto, Tomohiro Nakagawa, Kazuhiko Umemura, Masayuki Koyano, Yuya Hirokawa, Takuya Saiga, Hiroki Hagiwara
  • Patent number: 11021625
    Abstract: An ink includes a coloring material, an acrylic resin particle, an organic solvent, and water, wherein a solid dry film of the ink has a breaking elongation ratio of 50 percent or more, a storage elastic modulus G? of 1.0×106 Pa or more at 50 degrees C., and a swelling ratio of 40 percent or less to ethylacetate.
    Type: Grant
    Filed: June 26, 2019
    Date of Patent: June 1, 2021
    Assignee: Ricoh Company, Ltd.
    Inventors: Ryota Iwasaki, Ryo Miyakoshi, Yuya Hirokawa
  • Publication number: 20200238731
    Abstract: An image forming method is provided. The method includes the steps of (a) applying an ink to a recording medium to form an image and (b) applying a pressure to the recording medium to which the ink has been applied. The ink comprises water, an organic solvent, and a colorant. When the ink is formed into an ink film, a maximum value of logarithmic damping ratio of the ink film is 1.50 or less and a time elapsed until the logarithmic damping ratio reaches the maximum value is 3,800 seconds or less, when measured by a rigid-body pendulum test at 60° C.
    Type: Application
    Filed: April 17, 2020
    Publication date: July 30, 2020
    Inventors: Shun SAITO, Hiromi Sakaguchi, Takashi Tamai, Sayuri Kojima, Yuya Hirokawa
  • Patent number: 10723142
    Abstract: An image forming method is provided. The method includes the steps of (a) applying an ink to a recording medium to form an image and (b) applying a pressure to the recording medium to which the ink has been applied. The ink comprises water, an organic solvent, and a colorant. When the ink is formed into an ink film, a maximum value of logarithmic damping ratio of the ink film is 1.50 or less and a time elapsed until the logarithmic damping ratio reaches the maximum value is 3,800 seconds or less, when measured by a rigid-body pendulum test at 60° C.
    Type: Grant
    Filed: October 25, 2017
    Date of Patent: July 28, 2020
    Assignee: Ricoh Company, Ltd.
    Inventors: Shun Saito, Hiromi Sakaguchi, Takashi Tamai, Sayuri Kojima, Yuya Hirokawa