Patents by Inventor Junko Matsushita

Junko Matsushita 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: 9714338
    Abstract: An object of the present invention is to provide a polymer composition having properties resembling those of natural rubber, e.g. good durability (fracture resistance, wear resistance, and crack growth resistance), and a method for manufacturing the polymer composition. Specifically, the present invention provides a method for manufacturing a polymer composition including a mixture of polyisoprene and polystyrene/polybutadiene, comprising: polymerizing styrene monomer or butadiene monomer in the presence of a catalyst to synthesize polystyrene or polybutadiene; adding isoprene monomer to the polystyrene or polybutadiene thus synthesized, to synthesize polyisoprene and thus generate said mixture, wherein content of the styrene monomer or the butadiene monomer is set to be 10 mol % or less with respect to the total quantity of the styrene monomer/the butadiene monomer and the isoprene monomer.
    Type: Grant
    Filed: July 11, 2013
    Date of Patent: July 25, 2017
    Assignee: BRIDGESTONE CORPORATION
    Inventors: Satoru Tamaki, Shojiro Kaita, Junko Matsushita
  • Patent number: 9701776
    Abstract: The present invention provides a random copolymer that is used for manufacturing a rubber having high fracture strength and excellent low loss properties (low heat generation properties) and that includes randomly arranged monomer units of a conjugated diene compound and of a non-conjugated olefin, a rubber composition containing the random copolymer, a cross-linked rubber composition obtained by crosslinking the rubber composition, and a tire manufactured by using the rubber composition or the cross-linked rubber composition. A copolymer of a conjugated diene compound and a non-conjugated olefin includes a random copolymer having randomly arranged monomer units of the conjugated diene compound and of the non-conjugated olefin, which random copolymer contains, by at least 5 mol %, alternate bonding units of the conjugated diene compound and the non-conjugated olefin in a unit derived from the non-conjugated olefin.
    Type: Grant
    Filed: February 3, 2012
    Date of Patent: July 11, 2017
    Assignee: BRIDGESTONE CORPORATION
    Inventors: Yasuo Horikawa, Shojiro Kaita, Olivier Tardif, Junko Matsushita
  • Patent number: 9670302
    Abstract: Provided is a copolymer of a conjugated diene compound and a non-conjugated olefin, the copolymer being a tapered copolymer including: at least one of a block sequence including monomer units of the conjugated diene compound and a block sequence including monomer units of the non-conjugated olefin; and a random sequence including randomly arranged monomer units of the conjugated diene compound and monomer units of the non-conjugated olefin.
    Type: Grant
    Filed: July 26, 2011
    Date of Patent: June 6, 2017
    Assignee: BRIDGESTONE CORPORATION
    Inventors: Yasuo Horikawa, Shojiro Kaita, Olivier Tardif, Junko Matsushita
  • Patent number: 9623705
    Abstract: The invention provides a method for producing a modified conjugated diene (co)polymer, the method including comprising: a modification reaction step including causing an organic silane compound to react with a conjugated diene (co)polymer having an active site at the active site, the organic silane compound having a characteristic group for forming a silanol group through hydrolysis and, in the vicinity of the characteristic group, (i) a functional group which binds the organic silane compound to the conjugated diene (co)polymer via addition to or substitution at the active site and which promotes reaction between the silanol group and a reinforcing filler after the addition or substitution reaction, or (ii) a functional group which promotes reaction between the silanol group and a reinforcing filler, and a hydrolyzation step performed after the modification reaction step; a modified conjugated diene (co)polymer having, at a molecular end of the conjugated diene (co)polymer, a silanol group, and a functional
    Type: Grant
    Filed: March 10, 2009
    Date of Patent: April 18, 2017
    Assignee: BRIDGESTONE CORPORATION
    Inventors: Ken Tanaka, Noriko Mori, Yuki Itoh, Yoichi Ozawa, Ryuji Nakagawa, Junko Matsushita, Shigeaki Matsuo, Kouji Masaki, Fumihiro Shiraishi, Fuminori Oota
  • Patent number: 9540464
    Abstract: The polymer of the present invention is a synthesized polyisoprene or an isoprene copolymer. The polymer has a number average molecular weight (Mn) of 1.5 million or more when measured by using gel permeation chromatography (GPC).
    Type: Grant
    Filed: March 6, 2013
    Date of Patent: January 10, 2017
    Assignee: BRIDGESTONE CORPORATION
    Inventors: Junko Matsushita, Shojiro Kaita, Satoru Tamaki
  • Patent number: 9499647
    Abstract: Provided are: a polymer capable of providing a crosslinked rubber composition with improved durability (i.e., breaking resistance, abrasion resistance, and crack growth resistance) and a method for producing the same, a rubber composition containing the polymer, a crosslinked rubber composition obtained by crosslinking the rubber composition, and a tire having the crosslinked rubber composition. The polymer is either a synthesized polyisoprene or an isoprene copolymer, and contains a residual catalyst in an amount of 300 ppm or less.
    Type: Grant
    Filed: March 6, 2013
    Date of Patent: November 22, 2016
    Assignee: BRIDGESTONE CORPORATION
    Inventors: Junko Matsushita, Shojiro Kaita, Satoru Tamaki
  • Patent number: 9284384
    Abstract: A method for producing a polymer containing silica that does not involve long kneading time, and a polymer composition having an intended low heat generation property. A polymerization catalyst composition is produced by mixing and aging a second element and a third element, and then adding a first element to the mixture to react the first element with the mixture. The first element contains a compound that contains a rare earth metal element, the second element contains a compound represented by the following formula (X), and the third element contains silica. YR1aR2bR3c (X) (In the formula, Y is a metal; R1 and R2 are hydrogen atoms or hydrocarbon groups; and R3 is a hydrocarbon group, and R1, R2, and R3 are the same as or different from each other, a, b, and c are 0 or 1.).
    Type: Grant
    Filed: April 18, 2013
    Date of Patent: March 15, 2016
    Assignee: BRIDGESTONE CORPORATION
    Inventors: Junko Matsushita, Shojiro Kaita
  • Patent number: 9212274
    Abstract: The present invention provides a rubber composition that is used for manufacturing a rubber excellent in weather resistance, fracture resistance and crack growth resistance, and that contains a conjugated diene compound/non-conjugated olefin copolymer, a conjugate diene-based polymer and a non-conjugated diene compound/non-conjugated olefin copolymer, a rubber composition for tire side use using the rubber composition for tire sidewall members, a crosslinked rubber composition obtained by crosslinking the rubber composition, and a tire. The rubber composition includes: (A) a conjugated diene compound/non-conjugated olefin copolymer containing a conjugated diene compound-derived unit by at least 40 mol %; (B) a conjugated diene-based polymer; and (C) a non-conjugated diene compound/non-conjugated olefin copolymer containing an ethylene-propylene-diene rubber.
    Type: Grant
    Filed: February 27, 2012
    Date of Patent: December 15, 2015
    Assignee: BRIDGESTONE CORPORATION
    Inventors: Junko Matsushita, Yasuo Horikawa, Shojiro Kaita, Olivier Tardif
  • Patent number: 9181376
    Abstract: Provided is a copolymer of a conjugated diene compound and a non-conjugated olefin, the copolymer being a block copolymer, the conjugated diene compound unit having 1,2 adduct (including 3,4 adduct) content of 5% or less or the conjugated diene compound unit having a cis-1,4 bond content of more than 92%, in which preferred examples of the conjugated diene compound include 1,3-butadiene and isoprene, and preferred examples of the non-conjugated olefin include ethylene, propylene, and 1-butene.
    Type: Grant
    Filed: July 26, 2011
    Date of Patent: November 10, 2015
    Assignee: BRIDGESTONE CORPORATION
    Inventors: Yasuo Horikawa, Shojiro Kaita, Olivier Tardif, Junko Matsushita
  • Patent number: 9139680
    Abstract: Provided is a block copolymer of a conjugated diene compound and a non-conjugated olefin, a rubber composition including the block copolymer, a crosslinked rubber obtained by crosslinking the rubber composition, and a tire using the rubber composition or the crosslinked rubber composition. The copolymer of the present invention is a block copolymer of a conjugated diene compound and a non-conjugated olefin, the copolymer having a peak area in a temperature range in a range of 70° C. to 110° C. that accounts for at least 60% of a peak area in a range of 40° C. to 140° C. and a peak area in a range of 110° C. to 140° C. that accounts for 20% or less of a peak area in a range of 40° C. to 140° C., the peak areas being measured by the differential scanning calorimetry (DSC) according to JIS K 7121-1987.
    Type: Grant
    Filed: May 29, 2012
    Date of Patent: September 22, 2015
    Assignee: BRIDGESTONE CORPORATION
    Inventors: Yasuo Horikawa, Shojiro Kaita, Olivier Tardif, Junko Matsushita
  • Publication number: 20150232602
    Abstract: A copolymer having properties (durability (fracture resistance, abrasion resistance, and crack-growth resistance)) similar to those of natural rubber and a method of producing the copolymer are provided. An isoprene copolymer has a styrene block or a butadiene block at a terminal thereof, wherein styrene monomers account for less than 5 mol % of all monomers forming the isoprene copolymer having the styrene block; butadiene monomers account for 10 mol % or less of all monomers forming the isoprene copolymer having the butadiene block; and cis-1,4 bond content of a portion derived from isoprene accounts for at least 95% in total.
    Type: Application
    Filed: July 11, 2013
    Publication date: August 20, 2015
    Applicant: BRIDGESTONE CORPORATION
    Inventors: Satoru Tamaki, Junko Matsushita, Shojiro Kaita
  • Publication number: 20150197630
    Abstract: An object of the present invention is to provide a polymer composition having properties resembling those of natural rubber, e.g. good durability (fracture resistance, wear resistance, and crack growth resistance), and a method for manufacturing the polymer composition. Specifically, the present invention provides a method for manufacturing a polymer composition including a mixture of polyisoprene and polystyrene/polybutadiene, comprising: polymerizing styrene monomer or butadiene monomer in the presence of a catalyst to synthesize polystyrene or polybutadiene; adding isoprene monomer to the polystyrene or polybutadine thus synthesized, to synthesize polyisoprene and thus generate said mixture, wherein content of the styrene monomer or the butadiene monomer is set to be 10 mol % or less with respect to the total quantity of the styrene monomer/the butadiene monomer and the isoprene monomer.
    Type: Application
    Filed: July 11, 2013
    Publication date: July 16, 2015
    Applicant: BRIDGESTONE CORPORATION
    Inventors: Satoru Tamaki, Shojiro Kaita, Junko Matsushita
  • Patent number: 9056936
    Abstract: Provided is a copolymer of a conjugated diene compound and a non-conjugated olefin, the copolymer being a random copolymer including randomly arranged monomer units of the conjugated diene compound and of the non-conjugated olefin, in which the non-conjugated olefin is preferably an acyclic olefin, the non-conjugated olefin preferably has 2 to 10 carbon atoms, and specific examples of the non-conjugated olefin preferably include ethylene, propylene, and 1-butene.
    Type: Grant
    Filed: July 26, 2011
    Date of Patent: June 16, 2015
    Assignee: BRIDGESTONE CORPORATION
    Inventors: Yasuo Horikawa, Shojiro Kaita, Olivier Tardif, Junko Matsushita
  • Publication number: 20150112021
    Abstract: A method for producing a polymer containing silica that does not involve long kneading time, and a polymer composition having an intended low heat generation property. A polymerization catalyst composition is produced by mixing and aging a second element and a third element, and then adding a first element to the mixture to react the first element with the mixture. The first element contains a compound that contains a rare earth metal element, the second element contains a compound represented by the following formula (X), and the third element contains silica. YR1aR2bR3c (X) (In the formula, Y is a metal; R1 and R2 are hydrogen atoms or hydrocarbon groups; and R3 is a hydrocarbon group, and R1, R2, and R3 are the same as or different from each other, a, b, and c are 0 or 1.
    Type: Application
    Filed: April 18, 2013
    Publication date: April 23, 2015
    Applicant: BRIDGESTONE CORPORATION
    Inventors: Junko Matsushita, Shojiro Kaita
  • Patent number: 8987347
    Abstract: The present invention provides a copolymer of a conjugated diene compound and a non-conjugated olefin that is used for manufacturing a rubber excellent in crack growth resistance, heat resistance and ozone resistance and that includes a cis-1,4 bond at a unit derived from the conjugated diene compound, a rubber composition containing the copolymer, a rubber composition for tire treads using the rubber composition for tire tread members, a crosslinked rubber composition obtained by crosslinking the rubber composition, and a tire using the rubber composition or the crosslinked rubber composition. In the copolymer of a conjugated diene compound and a non-conjugated olefin, the cis-1,4 bond content of a unit derived from the conjugated diene compound is more than 92%.
    Type: Grant
    Filed: February 1, 2012
    Date of Patent: March 24, 2015
    Assignee: Bridgestone Corporation
    Inventors: Yasuo Horikawa, Shojiro Kaita, Olivier Tardif, Junko Matsushita
  • Publication number: 20150080525
    Abstract: Provided is a rubber composition including a rubber component. The rubber component contains at least a polymer that is a synthesized polyisoprene or an isoprene copolymer and that has 20% or less gel fraction.
    Type: Application
    Filed: March 6, 2013
    Publication date: March 19, 2015
    Applicant: BRIDGESTONE CORPORATION
    Inventors: Junko Matsushita, Shojiro Kaita, Satoru Tamaki
  • Patent number: 8962752
    Abstract: This invention relates to a rubber composition being excellent in the low heat buildup and fracture properties (resistance to crack growth). and more particularly to a rubber composition, characterized by compounding 10-100 parts by mass of an inorganic filler and/or carbon black based on 100 parts by mass of a rubber component including not less than 10 mass % of a modified conjugated diene-based polymer having a cis-1,4 bond content of not less than 90% and a vinyl bond content of not more than 1.2% and a primary amino group. In this case, the modified conjugated diene-based polymer is obtained by (1) reacting the predetermined conjugated diene-based polymer having an active terminal with a compound having two or more predetermined functional groups and (2) further reacting the resulting product with a compound having a primary amino group.
    Type: Grant
    Filed: April 22, 2014
    Date of Patent: February 24, 2015
    Assignee: Bridgestone Corporation
    Inventors: Junko Matsushita, Yoichi Ozawa
  • Patent number: 8962744
    Abstract: The present invention provides a random copolymer that is used for manufacturing a tire having excellent rollability and wear resistance and that includes randomly arranged monomer units of a conjugated diene compound and of a non-conjugated olefin, a rubber composition containing the random copolymer, a cross-linked rubber composition obtained by crosslinking the rubber composition, and a tire manufactured by using the rubber composition or the cross-linked rubber composition. A copolymer of a conjugated diene compound and a non-conjugated olefin, including a random copolymer having randomly arranged monomer units of the conjugated diene compound and of the non-conjugated olefin, and containing, by more than 30 mol %, a unit derived from the conjugated diene compound.
    Type: Grant
    Filed: February 2, 2012
    Date of Patent: February 24, 2015
    Assignee: Bridgestone Corporation
    Inventors: Yasuo Horikawa, Shojiro Kaita, Olivier Tardif, Junko Matsushita
  • Publication number: 20150025173
    Abstract: Provided are: a polymer capable of providing a crosslinked rubber composition with improved durability (i.e., breaking resistance, abrasion resistance, and crack growth resistance) and a method for producing the same, a rubber composition containing the polymer, a crosslinked rubber composition obtained by crosslinking the rubber composition, and a tire having the crosslinked rubber composition. The polymer is either a synthesized polyisoprene or an isoprene copolymer, and contains a residual catalyst in an amount of 300 ppm or less.
    Type: Application
    Filed: March 6, 2013
    Publication date: January 22, 2015
    Applicant: BRIDGESTONE CORPORATION
    Inventors: Junko Matsushita, Shojiro Kaita, Satoru Tamaki
  • Publication number: 20150011701
    Abstract: The polymer of the present invention is a synthesized polyisoprene or an isoprene copolymer. The polymer has a number average molecular weight (Mn) of 1.5 million or more when measured by using gel permeation chromatography (GPC).
    Type: Application
    Filed: March 6, 2013
    Publication date: January 8, 2015
    Applicant: BRIDGESTONE CORPORATION
    Inventors: Junko Matsushita, Shojiro Kaita, Satoru Tamaki