Patents by Inventor Ryota KITAGO

Ryota KITAGO 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: 11571931
    Abstract: Provided are a method for manufacturing a rubber composition for a tire and a method for manufacturing a tire including this manufacturing method for the rubber composition in the present invention, which are characterized by including the steps of: starting to knead a rubber component, a sulfur donor, and a sulfur atom-containing vulcanization accelerator together before kneading the rubber component with a filler; and then adding a filler to an obtained kneaded product and performing kneading at a kneading temperature of 120° C. or higher. According to the manufacturing methods of the present invention, a rubber composition for a tire and a tire which have good fracture property can be manufactured.
    Type: Grant
    Filed: September 21, 2016
    Date of Patent: February 7, 2023
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Ryota Kitago, Ryuichi Tokimune, Soh Ishino
  • Publication number: 20220389206
    Abstract: The present disclosure provides a tire having excellent enduring performance. The present disclosure relates to a tire including a tread containing a rubber composition, the rubber composition satisfying the following relationships 1) to 3) when measured within 180 days after vulcanization: 1) Hso/Hsa×100?95 wherein Hso: hardness at room temperature, Hsa: hardness at room temperature after heat treatment at 80° C. for 168 hours; 2) As/Ts×100?70 wherein Ts: sulfur content before acetone extraction, As: sulfur content after acetone extraction; and 3) Swell?330 wherein Swell: toluene swelling index.
    Type: Application
    Filed: July 9, 2020
    Publication date: December 8, 2022
    Applicant: Sumitomo Rubber Industries, Ltd.
    Inventors: Ryota KITAGO, Daisuke SATO, Hayato YOSHIYASU, Akihiro TAKEUCHI
  • Patent number: 11458767
    Abstract: A pneumatic tire includes bead cores, a carcass ply, an inner liner and the tread, and the crosslinked rubber composition, of the present invention, wherein the tread and the crosslinked rubber composition have a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5 or less at elongation by an applied stress of 3.0 MPa and a ratio of 40% by mass or more of a component having a weight-average molecular weight of not less than 1,000,000 in a molecular weight distribution measured by gel permeation chromatography are excellent in abrasion resistance.
    Type: Grant
    Filed: October 21, 2016
    Date of Patent: October 4, 2022
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Ryo Mashita, Hiroyuki Kishimoto, Ryota Kitago
  • Patent number: 11440349
    Abstract: The pneumatic tire of the present invention characterized by comprising: bead cores, a carcass ply, an inner liner and a tread having a volume of the low density region of 35% or more, at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5% or less at elongation by an applied stress of 3.0 MPa and a glass transition temperature of ?20° C. or lower, and the crosslinked rubber composition of the present invention having a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5 or less at elongation by an applied stress of 3.0 MPa and a glass transition temperature of ?20° C. or lower are excellent in abrasion resistance.
    Type: Grant
    Filed: October 21, 2016
    Date of Patent: September 13, 2022
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Ryo Mashita, Hiroyuki Kishimoto, Ryota Kitago
  • Patent number: 11427029
    Abstract: A pneumatic tire includes bead cores, a carcass ply, an inner liner, and a tread having a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5% or less at elongation by an applied stress of 3.0 MPa and a hardness of 65 or more and the crosslinked rubber composition of the present invention having a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5 or less at elongation by an applied stress of 3.0 MPa and a hardness of 65 or more are excellent in abrasion resistance.
    Type: Grant
    Filed: October 21, 2016
    Date of Patent: August 30, 2022
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Ryo Mashita, Hiroyuki Kishimoto, Ryota Kitago
  • Publication number: 20220220287
    Abstract: The purpose is to provide rubber compositions and pneumatic tires which have reduced changes in tan ? over time. The present invention relates to rubber compositions containing at least one copolymer obtained by copolymerizing an aromatic vinyl compound and a conjugated diene compound, the rubber compositions having a heat aging resistance index defined by equation (1) of 2.0 or less.
    Type: Application
    Filed: October 15, 2019
    Publication date: July 14, 2022
    Applicant: Sumitomo Rubber Industries, Ltd.
    Inventors: Ryota KITAGO, Rie YASUDA, Shogo HIRAO
  • Publication number: 20220119626
    Abstract: The purpose is to provide rubber compositions and pneumatic tires which have reduced changes in complex modulus E* over time. The present invention relates to rubber compositions containing at least one copolymer obtained by copolymerizing an aromatic vinyl compound and a conjugated diene compound, the rubber compositions having a heat aging resistance index defined by equation (1) of 27 or less.
    Type: Application
    Filed: October 15, 2019
    Publication date: April 21, 2022
    Applicant: Sumitomo Rubber Industries, Ltd.
    Inventors: Ryota KITAGO, Rie YASUDA, Shogo HIRAO
  • Publication number: 20220017729
    Abstract: The purpose is to provide rubber compositions and pneumatic tires which have reduced changes in hardness over time. The present invention relates to a rubber composition containing a copolymer obtained by copolymerizing an aromatic vinyl compound and a conjugated diene compound, the rubber composition having a heat aging resistance index defined by equation (1) of 10 or less.
    Type: Application
    Filed: October 15, 2019
    Publication date: January 20, 2022
    Applicant: Sumitomo Rubber Industries, Ltd.
    Inventors: Ryota KITAGO, Rie YASUDA, Shogo HIRAO
  • Publication number: 20210371628
    Abstract: The purpose is to provide rubber compositions and pneumatic tires which have reduced changes in tan ? peak temperature over time. The present invention relates to rubber compositions containing at least one copolymer obtained by copolymerizing an aromatic vinyl compound and a conjugated diene compound, the rubber compositions having a heat aging resistance index defined by equation (1) of 0.45 or less.
    Type: Application
    Filed: October 15, 2019
    Publication date: December 2, 2021
    Applicant: Sumitomo Rubber Industries, Ltd.
    Inventors: Ryota KITAGO, Rie YASUDA, Shogo HIRAO
  • Patent number: 10654316
    Abstract: The pneumatic tire characterized by comprising the tread and the crosslinked rubber composition, of the present invention, wherein the tread and the crosslinked rubber composition comprise two or more kinds of rubber components and a filler and have a volume of the low density region of 35% or more, a volume of the void portion of 7.5 or less and a filler distribution D represented by the following formula (I) of 2.0 or less are excellent in abrasion resistance. D=(A1/B1)/(A0/B0)??(I) In the formula (I), A1 represents a volume fraction of a rubber component A in a filler gel, B1 represents a volume fraction of a rubber component B in a filler gel, A0 represents a volume fraction of a compounded rubber component A, B0 represents a volume fraction of a compounded rubber component B.
    Type: Grant
    Filed: October 21, 2016
    Date of Patent: May 19, 2020
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Ryo Mashita, Hiroyuki Kishimoto, Ryota Kitago
  • Patent number: 10639932
    Abstract: The pneumatic tire of the present invention characterized by comprising: bead cores, a carcass ply, an inner liner disposed at an inner side than the carcass ply in a direction of a tire diameter, and a tread disposed at an outer side than the carcass ply in a direction of a tire diameter and having a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5% or less at elongation by an applied stress of 3.0 MPa and a filler dispersibility index ?G* shown by the following equation (I) of 3 or less and the crosslinked rubber composition having a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5 or less at elongation by an applied stress of 3.0 MPa and a filler dispersibility index ?G* shown by the following equation (I) of 3 or less are excellent in abrasion resistance.
    Type: Grant
    Filed: October 21, 2016
    Date of Patent: May 5, 2020
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Ryo Mashita, Hiroyuki Kishimoto, Ryota Kitago
  • Patent number: 10590254
    Abstract: The present invention provides rubber compositions that can achieve both abrasion resistance and low heat build-up properties, and pneumatic tires including such rubber compositions. The present invention relates to a rubber composition containing one or more carbon blacks, at least one of which is produced from a feedstock oil that has a BMCI value of not greater than 150 and an aliphatic hydrocarbon content of not less than 30% by mass.
    Type: Grant
    Filed: February 1, 2017
    Date of Patent: March 17, 2020
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Ryota Kitago, Yuuki Kawana
  • Patent number: 10479880
    Abstract: Provided are a rubber composition for tires which achieves both abrasion resistance and processability while maintaining fuel economy, and a pneumatic tire including the rubber composition. A rubber composition for tires, containing an organosilicon compound represented by the average compositional formula (I) below having a ratio of the number of sulfur atoms to the number of silicon atoms of 1.0 to 1.5, wherein x represents the average number of sulfur atoms; m represents an integer of 6 to 12; and R1 to R6 are the same or different and each represent a C1-C6 alkyl or alkoxy group, at least one of R1 to R3 and at least one of R4 to R6 are the alkoxy groups, and two or more of the alkyl or alkoxy groups for R1 to R6 may be joined to form a ring.
    Type: Grant
    Filed: September 21, 2017
    Date of Patent: November 19, 2019
    Assignees: SUMITOMO RUBBER INDUSTRIES, LTD., SHIN-ETSU CHEMICAL CO., LTD.
    Inventors: Ryuichi Tokimune, Tsuyoshi Tsuchida, Ryota Kitago, Soh Ishino, Hiroyuki Kishimoto, Munenao Hirokami, Tetsuro Yamada
  • Patent number: 10414906
    Abstract: The present invention aims to provide pneumatic tires that can achieve both abrasion resistance and low heat build-up properties. The present invention relates to a pneumatic tire including a tread formed from a rubber composition, the rubber composition containing: a rubber component including an isoprene-based rubber and a high-cis polybutadiene rubber having a cis content of 90% by mass or more; one or more types of carbon black; and sulfur, at least one of the one or more types of carbon black being produced from a feedstock oil that has a BMCI value of 150 or less and an aliphatic hydrocarbon content of 30% by mass or more, the BMCI value being calculated from the average boiling point T (° C.) and the specific gravity D (60/60° F.) relative to water at 60° F. according to the equation below, BMCI=48,640/(T+273)+473.7D?456.8.
    Type: Grant
    Filed: September 30, 2015
    Date of Patent: September 17, 2019
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Ryota Kitago, Takayuki Nagase, Yuuki Kawana, Takayuki Hattori, Takao Wada, Soh Ishino, Yuhei Yamashiro, Masaki Oshimo, Masanobu Nakamura
  • Patent number: 10280286
    Abstract: A method for manufacturing a rubber composition includes kneading a rubber component, an inorganic filler and a thioester-based silane coupling agent, and adding a vulcanizing agent and one or more compounds selected from the group of an imide compound and an N-oxyl compound to a mixture of the rubber component, the inorganic filler, and the thioester-based silane coupling agent such that the vulcanizing agent and the imide compound and/or the N-oxyl compound are kneaded with the mixture including the rubber component, the inorganic filler, and the thioester-based silane coupling agent.
    Type: Grant
    Filed: April 10, 2017
    Date of Patent: May 7, 2019
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Ryota Kitago, Yasumasa Bito, Ryuichi Tokimune
  • Publication number: 20180304683
    Abstract: The pneumatic tire of the present invention characterized by comprising: bead cores, a carcass ply, an inner liner and a tread having a volume of the low density region of 35% or more, at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5% or less at elongation by an applied stress of 3.0 MPa and a glass transition temperature of ?20° C. or lower, and the crosslinked rubber composition of the present invention having a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5 or less at elongation by an applied stress of 3.0 MPa and a glass transition temperature of ?20° C. or lower are excellent in abrasion resistance.
    Type: Application
    Filed: October 21, 2016
    Publication date: October 25, 2018
    Applicant: SUMITOMO RUBBER INDUSTRIES LTD.
    Inventors: Ryo MASHITA, Hiroyuki KISHIMOTO, Ryota KITAGO
  • Publication number: 20180305504
    Abstract: The present invention provides a rubber composition having good abrasion resistance and a pneumatic tire formed from the rubber composition. Provided is a rubber composition containing: a rubber component including a diene rubber; and a particulate zinc carrier, the particulate zinc carrier including a silicate particle and finely divided zinc oxide or finely divided basic zinc carbonate supported on the surface of the silicate particle.
    Type: Application
    Filed: March 26, 2018
    Publication date: October 25, 2018
    Applicant: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventor: Ryota KITAGO
  • Publication number: 20180304682
    Abstract: A pneumatic tire includes bead cores, a carcass ply, an inner liner and the tread, and the crosslinked rubber composition, of the present invention, wherein the tread and the crosslinked rubber composition have a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5 or less at elongation by an applied stress of 3.0 MPa and a ratio of 40% by mass or more of a component having a weight-average molecular weight of not less than 1,000,000 in a molecular weight distribution measured by gel permeation chromatography are excellent in abrasion resistance.
    Type: Application
    Filed: October 21, 2016
    Publication date: October 25, 2018
    Applicant: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Ryo MASHITA, Hiroyuki KISHIMOTO, Ryota KITAGO
  • Publication number: 20180297405
    Abstract: A pneumatic tire includes bead cores, a carcass ply, an inner liner, and a tread having a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5% or less at elongation by an applied stress of 3.0 MPa and a hardness of 65 or more and the crosslinked rubber composition of the present invention having a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5 or less at elongation by an applied stress of 3.0 MPa and a hardness of 65 or more are excellent in abrasion resistance.
    Type: Application
    Filed: October 21, 2016
    Publication date: October 18, 2018
    Applicant: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Ryo MASHITA, Hiroyuki KISHIMOTO, Ryota KITAGO
  • Publication number: 20180297403
    Abstract: Provided are a method for manufacturing a rubber composition for a tire and a method for manufacturing a tire including this manufacturing method for the rubber composition in the present invention, which are characterized by including the steps of: starting to knead a rubber component, a sulfur donor, and a sulfur atom-containing vulcanization accelerator together before kneading the rubber component with a filler; and then adding a filler to an obtained kneaded product and performing kneading at a kneading temperature of 120° C. or higher. According to the manufacturing methods of the present invention, a rubber composition for a tire and a tire which have good fracture property can be manufactured.
    Type: Application
    Filed: September 21, 2016
    Publication date: October 18, 2018
    Applicant: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Ryota KITAGO, Ryuichi TOKIMUNE, Soh ISHINO