Patents by Inventor Yuka Yokoyama

Yuka Yokoyama 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: 10066090
    Abstract: Provided are a rubber composition for tires that shows a balanced improvement in properties such as fuel economy, processability, heat aging resistance, abrasion resistance, wet-grip performance, performance on snow and ice, and handling stability, and a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition for tires, containing: a highly purified, modified natural rubber having a pH adjusted to 2-7; carbon black and/or a white filler; and a styrene-butadiene rubber having a styrene content of 30% by mass or more, and also relates to a pneumatic tire formed from the rubber composition.
    Type: Grant
    Filed: November 27, 2014
    Date of Patent: September 4, 2018
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Toshiaki Sakaki, Masanobu Nakamura, Yuka Yokoyama
  • Publication number: 20180236815
    Abstract: The present invention provides a cap tread rubber composition and a pneumatic tire formed from the rubber composition which are excellent in grip performance and abrasion resistance during high speed running. Provided is a cap tread rubber composition, containing: styrene butadiene rubber and/or polybutadiene rubber; an isoprene-based rubber; a filler; and a plasticizer, the rubber composition containing, based on 100% by mass of a rubber component therein, at least 90% by mass in total of the styrene butadiene rubber and/or polybutadiene rubber and 0.3% to 10% by mass of the isoprene-based rubber, the filler including, based on 100% by mass thereof, at least 80% by mass of silica, the rubber composition containing, per 100 parts by mass of the rubber component, at least 110 parts by mass of the silica and at least 50 parts by mass of the plasticizer.
    Type: Application
    Filed: January 11, 2018
    Publication date: August 23, 2018
    Applicant: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Yuka YOKOYAMA, Suguru IZUMO
  • Publication number: 20180093530
    Abstract: Provided is a cold weather tire achieving a balanced improvement in fuel economy, abrasion resistance, performance on ice and snow, and high-speed performance (handling stability, grip performance) on snow- and ice-free roads at low temperatures. The cold weather tire includes a cap tread formed of a rubber composition that contains: a rubber component including polybutadiene rubber, styrene butadiene rubber, and natural rubber and/or polyisoprene rubber; and a filler, the rubber composition having a combined amount of the natural rubber, polyisoprene rubber, and polybutadiene rubber of 80% by mass or more, an amount of the polybutadiene rubber of 30% by mass or more, and an amount of the styrene butadiene rubber of 0.3-10% by mass, each based on 100% by mass of the rubber component, the filler including 60% by mass or more of silica based on 100% by mass of the filler, the cap tread having cells and/or voids.
    Type: Application
    Filed: September 29, 2017
    Publication date: April 5, 2018
    Applicant: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Shuichiro ONO, Yuka YOKOYAMA
  • Publication number: 20180093531
    Abstract: Provided are a cap tread rubber composition for cold weather tires enabling a balanced improvement in fuel economy, abrasion resistance, performance on ice/snow, and high-speed performance on snow-/ice-free cold roads, and a cold weather tire formed from the same. The rubber composition contains: a rubber component including BR, SBR, and NR and/or IR; and a filler, the composition having a combined amount of NR, IR, and BR of 80% by mass or more, an amount of BR of 30% by mass or more, and an amount of SBR of 0.3-10% by mass, each per 100% by mass of the rubber component, the filler including 60% by mass or more of silica per 100% by mass of the filler, the composition containing, per 100 parts by mass of the rubber component, 50 parts by mass or more of a fine particle silica having a N2SA of 190 m2/g or more.
    Type: Application
    Filed: September 29, 2017
    Publication date: April 5, 2018
    Applicant: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Yuka Yokoyama, Shuichiro Ono
  • Publication number: 20180093533
    Abstract: The present invention provides a cold weather tire achieving a balanced improvement in conductivity, fuel economy, performance on ice and snow, high speed performance (handling stability, grip performance) on snow- and ice-free cold roads, and road noise performance. Provided is a pneumatic tire including: a two-layer tread including a base tread and a cap tread, the base tread being formed of a rubber composition for base treads containing: predetermined amounts of a rubber component including natural rubber and/or polyisoprene rubber, and a filler including silica and carbon black, the cap tread being formed of a rubber composition for cap treads containing a predetermined amount of silica, the cap tread having cells and/or voids.
    Type: Application
    Filed: September 29, 2017
    Publication date: April 5, 2018
    Applicant: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Yuka YOKOYAMA, Shuichiro ONO
  • Publication number: 20180030250
    Abstract: Provided are a rubber composition for tires that shows a balanced improvement in fuel economy, abrasion resistance, wet performance, and handling stability, and a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition for tires containing a modified diene rubber containing a functional group reactive with silica, a fine particle silica having a nitrogen adsorption specific surface area of 180 m2/g or more, and a silane coupling agent represented by a specific formula.
    Type: Application
    Filed: February 15, 2016
    Publication date: February 1, 2018
    Applicant: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventor: Yuka YOKOYAMA
  • Publication number: 20180030248
    Abstract: Provided are a rubber composition for tires that achieves a balanced improvement in fuel economy, abrasion resistance, and performance on ice, and a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition for tires containing predetermined amounts of natural rubber, polybutadiene rubber, silica, and a silane coupling agent represented by a specific formula.
    Type: Application
    Filed: February 15, 2016
    Publication date: February 1, 2018
    Applicant: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Seiji HATANO, Yuka YOKOYAMA
  • Patent number: 9879109
    Abstract: Provided are rubber compositions for tires capable of providing tire components and pneumatic tires that have the same level of fuel efficiency and wet grip performance (particularly, wet grip performance) as those of tire components and pneumatic tires containing conventional synthetic rubber, while satisfying the requirements for a sound material-cycle society. The present invention relates to rubber compositions for tires containing a biomass-derived rubber polymerized from an aromatic vinyl compound and a diene, the biomass-derived rubber having a pMC (percent modern carbon) measured in accordance with ASTM D 6866-10 of 1% or higher.
    Type: Grant
    Filed: September 6, 2013
    Date of Patent: January 30, 2018
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Ryoji Kojima, Yuka Yokoyama, Masafumi Yoshino
  • Patent number: 9862814
    Abstract: Provided are pneumatic tires or studless winter tires that achieve a balanced improvement in fuel economy, reinforcing properties (flex crack growth resistance, abrasion resistance, tensile strength, adhesive strength, resistance to air permeation), grip performance (wet-grip performance, performance on snow and ice), handling stability, and heat aging resistance, and methods for producing such a pneumatic tire or studless winter tire. The present invention relates to a pneumatic tire including at least one component selected from the group consisting of a sidewall, a base tread, a bead apex, a clinch apex, an innerliner, and an undertread, each of which is formed from a rubber composition that contains a highly purified, modified natural rubber whose pH is adjusted to 2 to 7, and carbon black and/or a white filler.
    Type: Grant
    Filed: May 12, 2014
    Date of Patent: January 9, 2018
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Toshiaki Sakaki, Yuka Yokoyama
  • Patent number: 9856362
    Abstract: Provided are a rubber composition for tires that shows a balanced improvement in properties such as fuel economy, processability, heat aging resistance, abrasion resistance, wet-grip performance, performance on snow and ice, and handling stability, and a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition for tires, containing: a highly purified, modified natural rubber having a pH adjusted to 2 to 7, and a silica having a CTAB specific surface area of 180 m2/g or more and a BET specific surface area of 185 m2/g or more, and also relates to a pneumatic tire formed from the rubber composition.
    Type: Grant
    Filed: November 27, 2014
    Date of Patent: January 2, 2018
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Toshiaki Sakaki, Yuka Yokoyama, Seiji Hatano
  • Publication number: 20170355836
    Abstract: A method for manufacturing a tire rubber composition includes kneading a rubber component, a silane coupling agent and a silica having a BET specific surface area of 210 m2/g or more, adding a vulcanization accelerator to a first kneaded material including the rubber component, silane coupling agent and silica, kneading a first resulting mixture including the rubber component, silane coupling agent, silica and vulcanization accelerator such that a second kneaded material including the rubber component, silane coupling agent, silica and vulcanization accelerator is obtained, adding a vulcanization agent to the second kneaded material including the rubber component, silane coupling agent, silica and vulcanization accelerator, and kneading a second resulting mixture including the rubber component, silane coupling agent, silica, vulcanization accelerator and vulcanization agent. The first kneaded material has a pH of 6.5 or less, and the second kneaded material has a pH of 8.0 or more.
    Type: Application
    Filed: May 30, 2017
    Publication date: December 14, 2017
    Applicant: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventor: Yuka YOKOYAMA
  • Publication number: 20170327671
    Abstract: A method for manufacturing a tire rubber composition includes kneading a rubber component, a silane coupling agent and silica such that a content of the silica exceeds 50 parts by mass with respect to 100 parts by mass of the rubber component, adding a vulcanization accelerator to a kneading mixture including the rubber component, the silane coupling agent and the silica, kneading the vulcanization accelerator and the kneading mixture including the rubber component, the silane coupling agent and the silica, adding a vulcanization agent to a resulting mixture including the rubber component, the silane coupling agent, the silica and the vulcanization accelerator, and kneading the vulcanization agent and the resulting mixture including the rubber component, the silane coupling agent, the silica and the vulcanization accelerator such that a kneaded material obtained by the kneading of the vulcanization agent and the resulting mixture has a gel fraction of 30% or less.
    Type: Application
    Filed: May 12, 2017
    Publication date: November 16, 2017
    Applicant: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventor: Yuka YOKOYAMA
  • Publication number: 20170305192
    Abstract: To provide a rubber compound for tires, a pneumatic tire and an airless tire capable of improving the steering stability of the tire while exerting excellent low fuel consumption performance. A rubber compound for tires characterized in that, of vulcanized rubber's physical properties, a complex elastic modulus E*70 (unit: MPa) and a loss tangent tan?70 under initial strain of 10%, dynamic strain of 2% and temperature of 70 degrees C., satisfy 90<E70<250, and E*70/tan ?70>800. A pneumatic tire provided with a rubber member made of the above-mentioned rubber compound. An airless tire provided with a rubber member made of the above-mentioned rubber compound. An airless tire provided in a tread ring with a shear rubber layer made of the above-mentioned rubber compound.
    Type: Application
    Filed: September 30, 2015
    Publication date: October 26, 2017
    Applicant: Sumitomo Rubber Industries, Ltd.
    Inventors: Yuka YOKOYAMA, Mutsuki SUGIMOTO, Wako IWAMURA, Makoto SUGIYA
  • Patent number: 9732165
    Abstract: Provided are a rubber composition for tires that shows a balanced improvement in properties such as fuel economy, processability, heat aging resistance, abrasion resistance, wet-grip performance, performance on snow and ice, and handling stability, and a pneumatic tire formed from the rubber composition.
    Type: Grant
    Filed: November 27, 2014
    Date of Patent: August 15, 2017
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Toshiaki Sakaki, Akira Minagoshi, Yuka Yokoyama
  • Publication number: 20170225512
    Abstract: According to a production method of a rubber composition for tire of the present invention comprising a rubber component (A) comprising at least one selected from the group consisting of a natural rubber and a synthetic diene rubber, a filler, a coupling agent (D) of (CpH2p+1O)3—Si—(CH2)q—S—CO—CkH2k+1, and a vulcanizing agent (E) comprising a vulcanizer and a vulcanization accelerator, the method comprising: a step X1 of kneading all amount of A, a part of the filler and a part of D, a step X2 of kneading the kneaded product of step X1, the remaining amount of the filler and D, and a step F of kneading the kneaded product of step X2 and E, it is possible to produce a rubber composition for tire in which fuel efficiency and abrasion resistance are improved in a good balance.
    Type: Application
    Filed: November 6, 2015
    Publication date: August 10, 2017
    Applicant: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Ayuko YAMANA, Yuka YOKOYAMA, Masako NAKATANI, Takashi MIKI, Takuya HORIGUCHI, Yoichi MIZUNO, Takahiro KAWACHI, Noboru OKABE, Natsuki SUGIMOTO, Kenichi UESAKA, Tetsuya MAEKAWA, Yumi SUZUKI, Fumiya KATO
  • Publication number: 20170218170
    Abstract: A rubber composition comprising silica that has a BET specific surface area of not more than 130 m2/g and hardness of granulated particles as measured based on JIS K6221-1982 6.3.3 of not less than 23.5 cN can provide a rubber composition which is excellent in rubber physical properties while maintaining energy efficiency. A tire comprising a component consisted of the rubber composition can be also provided.
    Type: Application
    Filed: July 29, 2015
    Publication date: August 3, 2017
    Applicant: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Seiji HATANO, Yuka YOKOYAMA, Kouhei TANAKA, Akira MINAGOSHI, Kazuo HOCHI, Masanobu NAKAMURA, Toshikazu KONDO, Kenichiro OGATA
  • Publication number: 20170194503
    Abstract: A highly reliable semiconductor device which uses an oxide semiconductor film for a backplane is provided. A semiconductor device includes a first conductive film, a first insulating film over the first conductive film, an oxide semiconductor film which is over the first insulating film and overlaps with the first conductive film, a second insulating film over the oxide semiconductor film, and a pair of second conductive films electrically connected to the oxide semiconductor film through an opening portion included in the second insulating film. The second insulating film overlaps with a region of the oxide insulating film in which a carrier flows between the pair of second conductive films and overlaps with end portions of the oxide semiconductor film.
    Type: Application
    Filed: March 17, 2017
    Publication date: July 6, 2017
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Masahiro KATAYAMA, Chieko MISAWA, Yuka YOKOYAMA, Hironobu TAKAHASHI, Kenichi OKAZAKI
  • Patent number: 9663445
    Abstract: The present invention provides a synthesis system that can synthesize aniline and/or styrene efficiently, a synthesis system that can synthesize butadiene (1,3-butadiene) efficiently, a rubber chemical for a tire which is synthesized from the aniline obtained by the synthesis system, a synthetic rubber for a tire which is synthesized from the styrene and/or butadiene obtained by the synthesis systems, and a pneumatic tire produced using the rubber chemical for a tire and/or the synthetic rubber for a tire. The present invention relates to a synthesis system for synthesizing aniline and/or styrene from an alcohol having two or more carbon atoms via an aromatic compound.
    Type: Grant
    Filed: July 16, 2015
    Date of Patent: May 30, 2017
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Takayuki Hattori, Takao Wada, Keitaro Fujikura, Yuka Yokoyama, Toshiro Matsuo
  • Patent number: 9657121
    Abstract: The present invention provides rubber compositions for tires capable of providing tire components and pneumatic tires having low-temperature properties and abrasion resistance that are equivalent to those of tire components and pneumatic tires formed from conventional synthetic rubber, respectively, while meeting the demand for a sound material-cycle society. The present invention relates to rubber compositions for tires containing a biomass-derived rubber obtained by polymerizing a biomass-derived monomer component, the biomass-derived rubber having a pMC (percent modern carbon) value of 1% or greater as determined in conformity with ASTM D6866-10, and having a Tg (glass transition temperature) value of ?120° C. to ?80° C.
    Type: Grant
    Filed: July 24, 2013
    Date of Patent: May 23, 2017
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Ryoji Kojima, Yuka Yokoyama
  • Patent number: 9601634
    Abstract: A highly reliable semiconductor device which uses an oxide semiconductor film for a backplane is provided. A semiconductor device includes a first conductive film, a first insulating film over the first conductive film, an oxide semiconductor film which is over the first insulating film and overlaps with the first conductive film, a second insulating film over the oxide semiconductor film, and a pair of second conductive films electrically connected to the oxide semiconductor film through an opening portion included in the second insulating film. The second insulating film overlaps with a region of the oxide insulating film in which a carrier flows between the pair of second conductive films and overlaps with end portions of the oxide semiconductor film.
    Type: Grant
    Filed: December 1, 2014
    Date of Patent: March 21, 2017
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Masahiro Katayama, Chieko Misawa, Yuka Yokoyama, Hironobu Takahashi, Kenichi Okazaki