Patents by Inventor Tetsuji Kawazura

Tetsuji Kawazura 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: 8557926
    Abstract: A modified polymer is produced by reacting (A) a polymer with (B) a compound having a nitroxide free radical in the molecule stable at room temperature and in the presence of oxygen, (C) an organic peroxide, and (D) a radically polymerizable monomer having a functional group in the presence of (E) an amine compound comprising a monoamine compound represented by the general formula: NR1R2R3 (R1: C1-C20 alkyl group or aryl group; R2 and R3: H, C1-C20 alkyl group, or aryl group) or a polyamine compound represented by the general formula: (R4)2N(R5N)nR6N(R4)2 (R4: H or C1-C6 alkyl group; R5 and R6: C1-C6 alkylene group; n: 0 to 20). This method can not only reduce the reaction temperature but also improve the modification rate.
    Type: Grant
    Filed: April 13, 2011
    Date of Patent: October 15, 2013
    Assignee: The Yokohama Rubber Co., Ltd.
    Inventors: Tetsuji Kawazura, Michiko Kawabata
  • Publication number: 20130053517
    Abstract: A modified polymer is produced by reacting (A) a polymer with (B) a compound having a nitroxide free radical in the molecule stable at room temperature and in the presence of oxygen, (C) an organic peroxide, and (D) a radically polymerizable monomer having a functional group in the presence of (E) an amine compound comprising a monoamine compound represented by the general formula: NR1R2R3 (R1: C1-C20 alkyl group or aryl group; R2 and R3: H, C1-C20 alkyl group, or aryl group) or a polyamine compound represented by the general formula: (R4)2N(R5N)nR6N(R4)2 (R4: H or C1-C6 alkyl group; R5 and R6: C1-C6 alkylene group; n: 0 to 20). This method can not only reduce the reaction temperature but also improve the modification rate.
    Type: Application
    Filed: April 13, 2011
    Publication date: February 28, 2013
    Applicant: YOKOHAMA RUBBER CO., LTD.
    Inventors: Tetsuji Kawazura, Michiko Kawabata
  • Patent number: 8310813
    Abstract: An electrolytic capacitor sealer is formed of a modified butyl rubber composition obtained by using an organic peroxide to crosslink a modified butyl rubber composition which has been modified by reacting butyl rubber with a compound (a) having in the molecule a nitroxide free radical that is stable at room temperature even in the presence of oxygen, a radical initiator (b), and a bifunctional or higher radical polymerizable monomer (c), and of a modified butyl rubber composition obtained by compounding a radical polymerizable monomer (c) with a modified butyl rubber composition that has been obtained by reacting butyl rubber with a compound (a) having in the molecule a nitroxide free radical that is stable at room temperature even in the presence of oxygen and a radical initiator (b), and then crosslinking the composition thus obtained with an organic peroxide.
    Type: Grant
    Filed: March 31, 2008
    Date of Patent: November 13, 2012
    Assignees: Nippon Chemi-Con Corporation, The Yokohama Rubber Co., Ltd.
    Inventors: Hiroaki Fujita, Kazuhiko Kimura, Masatoshi Iemura, Masashi Ozawa, Makoto Ashiura, Tetsuji Kawazura
  • Patent number: 8293827
    Abstract: A method for producing a rubber composition, the method including: preparing a modified natural rubber by releasing protein from rubber particles in a natural rubber latex by adding at least one organic compound selected from formaldehyde, paraformaldehyde, formalin, and glyoxal to the above mentioned natural rubber latex and then drying so as to include the released protein therein; and mixing at least one selected from carbon black and silica in this modified natural rubber. Such method reduces viscosity and improves molding processibility of the rubber composition, as well as reducing hysteresis loss.
    Type: Grant
    Filed: November 4, 2009
    Date of Patent: October 23, 2012
    Assignee: The Yokohama Rubber Co. Ltd
    Inventors: Takashi Matsuda, Makoto Ashiura, Tetsuji Kawazura
  • Patent number: 8034868
    Abstract: A rubber composition obtained by compounding thereinto a rubber component containing 0.5 to 100% by weight of a modified conjugated diene-based polymer having a fullerene bonded thereto in the molecule and having a weight average molecular weight of 50,000 or more excellent processability, superior balance of modulus and heat buildup, excellent cold flowability and superior tan ? balance.
    Type: Grant
    Filed: March 18, 2009
    Date of Patent: October 11, 2011
    Assignee: The Yokohama Rubber Co., Ltd.
    Inventors: Makoto Ashiura, Tetsuji Kawazura, Fumito Yatsuyanagi
  • Patent number: 7956134
    Abstract: A modified butyl rubber composition containing a modified butyl rubber obtained by a modification reaction of a compound (a) having a nitroxide-free radical, stable in the presence of oxygen at an ordinary temperature, in the molecule thereof and a radical initiator (b) and at least two kinds of bi- or more-functional radical polymerizable monomers (c).
    Type: Grant
    Filed: April 16, 2008
    Date of Patent: June 7, 2011
    Assignee: The Yokohama Rubber Co., Ltd.
    Inventors: Makoto Ashiura, Tetsuji Kawazura
  • Publication number: 20110086981
    Abstract: A manufacturing method for a surface-modified rubber molded body is described. An uncross-linked rubber molded body is made of a rubber composition containing an organic peroxide and a modified butyl rubber composition (A) containing a modified butyl rubber (1) where a compound (a) with a stable nitroxide free radical in the molecule at ambient temperature in the presence of oxygen, a radical initiator (b), and a radical polymeric monomer (c) with at least difunctionality are reacted with butyl rubber, or a modified butyl rubber composition (B) where the monomer (c) is added to a modified butyl rubber (2) where the compound (a) and the radical initiator (b) are reacted with butyl rubber. A siloxane compound having a (meth)acryloyl group is applied onto the surface of the uncross-linked rubber molded body. The uncross-linked rubber molded body is then heat-treated.
    Type: Application
    Filed: March 31, 2010
    Publication date: April 14, 2011
    Inventors: Makoto Ashiura, Tetsuji Kawazura
  • Patent number: 7812096
    Abstract: A method for modifying a polymer by mixing and reacting a polymer (A), a compound (B) having a nitroxide radical in the molecule thereof, a radical initiator (C), and a radical polymerizable monomer (D) in a non-solvent system in a mixed to thereby graft a monomer (D) to the polymer (A), whereby a desired functional group is introduced to the polymer, without a causing decrease in the molecular weight, gelation, or formation of a homopolymer.
    Type: Grant
    Filed: January 17, 2006
    Date of Patent: October 12, 2010
    Assignee: The Yokohama Rubber Co., Ltd.
    Inventors: Makoto Ashiura, Tetsuji Kawazura
  • Publication number: 20100232088
    Abstract: An electrolytic capacitor sealer capable of fulfilling the requirement such as long-term heat resistance without risk of reversion due to crosslinking with an organic peroxide and an electrolytic capacitor using such a sealer are provided.
    Type: Application
    Filed: March 31, 2008
    Publication date: September 16, 2010
    Inventors: Hiroaki Fujita, Kazuhiko Kimura, Masatoshi Iemura, Masashi Ozawa, Makoto Ashiura, Tetsuji Kawazura
  • Patent number: 7772325
    Abstract: A thermoplastic elastomer composition containing a dynamically cross-linked composition of (A) 10 to 70 parts by weight of a thermoplastic resin, (B) 30 to 90 parts by weight of a modified butyl rubber composition containing a modified butyl rubber modified reacting, to butyl rubber, (a) a compound containing, in the molecule thereof, a nitroxide free radical stable at ah ordinary temperature in the presence of oxygen, and (c) a bifunctional or higher functional radical polymerizable monomer, and (C) 0.01 to 15 parts by weight of a cross-linking agent.
    Type: Grant
    Filed: November 6, 2009
    Date of Patent: August 10, 2010
    Assignee: The Yokohama Rubber Co., Ltd.
    Inventors: Makoto Ashiura, Tetsuji Kawazura, Kazuo Arakawa
  • Patent number: 7754819
    Abstract: A thermoplastic elastomer having a side chain having a moiety crosslinkable by hydrogen bond containing a carbonyl-containing group and a nitrogen-containing heterocycle, and another side chain having a covalently crosslinkable moiety, the thermoplastic elastomer being able to be crosslinked at the covalently crosslinkable moiety by at least one bond selected from the group consisting of amide, ester, lactone, urethane, ether, thiourethane, and thioether. The thermoplastic elastomer exhibits excellent mechanical strength without detracting from its excellent recycleability.
    Type: Grant
    Filed: November 1, 2005
    Date of Patent: July 13, 2010
    Assignee: Yokohama Rubber Co., Ltd.
    Inventors: Keisuke Chino, Manabu Kato, Tetsuji Kawazura
  • Publication number: 20100120956
    Abstract: A method for producing a solid natural rubber by adding a compound having a quaternary ammonium ion and a carboxyl ion in the molecule thereof to a natural rubber latex and removing and drying a water content of the latex, whereby the increase in the viscosity during storage can be suppressed.
    Type: Application
    Filed: April 8, 2008
    Publication date: May 13, 2010
    Applicant: THE YOKOHAMA RUBBER CO., LTD.
    Inventors: Tetsuji Kawazura, Takashi Kakubo
  • Publication number: 20100113684
    Abstract: A method for producing a rubber composition, the method including: preparing a modified natural rubber by releasing protein from rubber particles in a natural rubber latex by adding at least one organic compound selected from formaldehyde, paraformaldehyde, formalin, and glyoxal to the above mentioned natural rubber latex and then drying so as to include the released protein therein; and mixing at least one selected from carbon black and silica in this modified natural rubber. Such method reduces viscosity and improves molding processibility of the rubber composition, as well as reducing hysteresis loss.
    Type: Application
    Filed: November 4, 2009
    Publication date: May 6, 2010
    Inventors: Takashi Matsuda, Makoto Ashiura, Tetsuji Kawazura
  • Patent number: 7700695
    Abstract: A modified butyl rubber composition comprising a butyl rubber modified by mixing, under heating, (a) a compound having a nitroxide-free radical in the molecule thereof, which is stable at an ordinary temperature even in the presence of oxygen, (b) a radical initiator, and (c) a bi- or more-functional radical polymerizable monomer and further by compounded with (d) a bi- or more-functional radical polymerizable monomer, which is different from the ingredient (c).
    Type: Grant
    Filed: September 29, 2008
    Date of Patent: April 20, 2010
    Assignee: The Yokohama Rubber Co., Ltd.
    Inventors: Makoto Ashiura, Tetsuji Kawazura
  • Publication number: 20100056723
    Abstract: A thermoplastic elastomer composition containing a dynamically cross-linked composition of (A) 10 to 70 parts by weight of a thermoplastic resin, (B) 30 to 90 parts by weight of a modified butyl rubber composition containing a modified butyl rubber modified reacting, to butyl rubber, (a) a compound containing, in the molecule thereof, a nitroxide free radical stable at ah ordinary temperature in the presence of oxygen, and (c) a bifunctional or higher functional radical polymerizable monomer, and (C) 0.01 to 15 parts by weight of a cross-linking agent.
    Type: Application
    Filed: November 6, 2009
    Publication date: March 4, 2010
    Applicant: The Yokohama Rubber Co., Ltd.
    Inventors: Makoto Ashiura, Tetsuji Kawazura, Kazuo Arakawa
  • Publication number: 20090292044
    Abstract: To modify a diene-based rubber whereby the dispersibility of silica and the abrasion resistance or heat buildup resistance are improved. A modified diene-based rubber obtained by adding and reacting, to a diene-based rubber (A), a compound (B) having, in the molecule thereof, a nitroxide free radical stable at an ordinary temperature and in the presence of oxygen, a radical initiator (C) and a radical polymerizable monomer (D) having a functional group in the molecule thereof and a rubber composition and pneumatic tire containing the same.
    Type: Application
    Filed: July 3, 2007
    Publication date: November 26, 2009
    Applicant: The Yokohama Rubber Co., Ltd.
    Inventors: Tetsuji Kawazura, Makoto Ashiura
  • Publication number: 20090247677
    Abstract: A production method of a low viscosity or low constant viscosity natural rubber obtained by treating a natural rubber latex by adding a water-soluble ammonium salt so as to decrease the metal content and spraying the treated natural rubber latex or the latex after addition of a constant viscosity agent into a pulse wave atmosphere for pulse drying to obtain solid rubber, a natural rubber obtained by the same, and a rubber composition including the same, whereby a low viscosity or low constant viscosity natural rubber having superior mechanical properties and low viscosity or low constant viscosity and superior processability, a natural rubber obtained by the same and a rubber composition containing the same were provided.
    Type: Application
    Filed: October 5, 2006
    Publication date: October 1, 2009
    Applicant: The Yokohama Rubber Co., Ltd.
    Inventors: Tetsuji Kawazura, Takashi Kakubo
  • Patent number: 7589155
    Abstract: A modified butyl rubber composition including a modified butyl rubber obtained by reacting a compound (a) having, in its molecule, a nitroxide free radical stable at an ordinary temperature in the presence of oxygen, a radical initiator (b), and a bifunctional or higher radical polymerizable monomer (c) or a modified butyl rubber composition containing a modified butyl rubber, obtained by reacting a compound (a) having, in its molecule, a nitroxide free radical stable at ordinary temperature in the presence of oxygen and a radical initiator (b), into which a bi- or more-functional radical polymerizable monomer (c) is compounded.
    Type: Grant
    Filed: October 20, 2006
    Date of Patent: September 15, 2009
    Assignee: The Yokohama Rubber Co., Ltd.
    Inventors: Makoto Ashiura, Tetsuji Kawazura
  • Publication number: 20090182069
    Abstract: A rubber composition obtained by compounding thereinto a rubber component containing 0.5 to 100% by weight of a modified conjugated diene-based polymer having a fullerene bonded thereto in the molecule and having a weight average molecular weight of 50,000 or more excellent processability, superior balance of modulus and heat buildup, excellent cold flowability and superior tan ? balance.
    Type: Application
    Filed: March 18, 2009
    Publication date: July 16, 2009
    Applicant: The Yokohama Rubber Co., Ltd.
    Inventors: Makoto Ashiura, Tetsuji Kawazura, Fumito Yatsuyanagi
  • Publication number: 20090156728
    Abstract: A modified butyl rubber composition capable cross-link an organic peroxide and having an improved modulus and strength at break is provided. A modified butyl rubber composition comprising a reaction product of (i) a rubber ingredient comprising a butyl rubber and (ii)(a) a compound having a nitroxide-free radical stable at ordinary temperature in the molecule thereof even in the presence of oxygen, (b) a radical initiator, (c) a bifunctional or higher radical polymerizable monomer and (d) a radical polymerizable monomer having an alkoxysilyl group, whereby.
    Type: Application
    Filed: December 12, 2008
    Publication date: June 18, 2009
    Applicant: The Yokohama Rubber Co., Ltd.
    Inventors: Makoto Ashiura, Tetsuji Kawazura