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).
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Patent number: 8557926Abstract: 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: GrantFiled: April 13, 2011Date of Patent: October 15, 2013Assignee: The Yokohama Rubber Co., Ltd.Inventors: Tetsuji Kawazura, Michiko Kawabata
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Publication number: 20130053517Abstract: 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: ApplicationFiled: April 13, 2011Publication date: February 28, 2013Applicant: YOKOHAMA RUBBER CO., LTD.Inventors: Tetsuji Kawazura, Michiko Kawabata
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Patent number: 8310813Abstract: 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: GrantFiled: March 31, 2008Date of Patent: November 13, 2012Assignees: Nippon Chemi-Con Corporation, The Yokohama Rubber Co., Ltd.Inventors: Hiroaki Fujita, Kazuhiko Kimura, Masatoshi Iemura, Masashi Ozawa, Makoto Ashiura, Tetsuji Kawazura
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Patent number: 8293827Abstract: 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: GrantFiled: November 4, 2009Date of Patent: October 23, 2012Assignee: The Yokohama Rubber Co. LtdInventors: Takashi Matsuda, Makoto Ashiura, Tetsuji Kawazura
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Patent number: 8034868Abstract: 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: GrantFiled: March 18, 2009Date of Patent: October 11, 2011Assignee: The Yokohama Rubber Co., Ltd.Inventors: Makoto Ashiura, Tetsuji Kawazura, Fumito Yatsuyanagi
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Patent number: 7956134Abstract: 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: GrantFiled: April 16, 2008Date of Patent: June 7, 2011Assignee: The Yokohama Rubber Co., Ltd.Inventors: Makoto Ashiura, Tetsuji Kawazura
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Publication number: 20110086981Abstract: 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: ApplicationFiled: March 31, 2010Publication date: April 14, 2011Inventors: Makoto Ashiura, Tetsuji Kawazura
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Patent number: 7812096Abstract: 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: GrantFiled: January 17, 2006Date of Patent: October 12, 2010Assignee: The Yokohama Rubber Co., Ltd.Inventors: Makoto Ashiura, Tetsuji Kawazura
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Publication number: 20100232088Abstract: 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: ApplicationFiled: March 31, 2008Publication date: September 16, 2010Inventors: Hiroaki Fujita, Kazuhiko Kimura, Masatoshi Iemura, Masashi Ozawa, Makoto Ashiura, Tetsuji Kawazura
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Patent number: 7772325Abstract: 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: GrantFiled: November 6, 2009Date of Patent: August 10, 2010Assignee: The Yokohama Rubber Co., Ltd.Inventors: Makoto Ashiura, Tetsuji Kawazura, Kazuo Arakawa
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Patent number: 7754819Abstract: 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: GrantFiled: November 1, 2005Date of Patent: July 13, 2010Assignee: Yokohama Rubber Co., Ltd.Inventors: Keisuke Chino, Manabu Kato, Tetsuji Kawazura
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Publication number: 20100120956Abstract: 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: ApplicationFiled: April 8, 2008Publication date: May 13, 2010Applicant: THE YOKOHAMA RUBBER CO., LTD.Inventors: Tetsuji Kawazura, Takashi Kakubo
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Publication number: 20100113684Abstract: 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: ApplicationFiled: November 4, 2009Publication date: May 6, 2010Inventors: Takashi Matsuda, Makoto Ashiura, Tetsuji Kawazura
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Patent number: 7700695Abstract: 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: GrantFiled: September 29, 2008Date of Patent: April 20, 2010Assignee: The Yokohama Rubber Co., Ltd.Inventors: Makoto Ashiura, Tetsuji Kawazura
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Publication number: 20100056723Abstract: 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: ApplicationFiled: November 6, 2009Publication date: March 4, 2010Applicant: The Yokohama Rubber Co., Ltd.Inventors: Makoto Ashiura, Tetsuji Kawazura, Kazuo Arakawa
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Publication number: 20090292044Abstract: 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: ApplicationFiled: July 3, 2007Publication date: November 26, 2009Applicant: The Yokohama Rubber Co., Ltd.Inventors: Tetsuji Kawazura, Makoto Ashiura
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Publication number: 20090247677Abstract: 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: ApplicationFiled: October 5, 2006Publication date: October 1, 2009Applicant: The Yokohama Rubber Co., Ltd.Inventors: Tetsuji Kawazura, Takashi Kakubo
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Patent number: 7589155Abstract: 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: GrantFiled: October 20, 2006Date of Patent: September 15, 2009Assignee: The Yokohama Rubber Co., Ltd.Inventors: Makoto Ashiura, Tetsuji Kawazura
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Publication number: 20090182069Abstract: 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: ApplicationFiled: March 18, 2009Publication date: July 16, 2009Applicant: The Yokohama Rubber Co., Ltd.Inventors: Makoto Ashiura, Tetsuji Kawazura, Fumito Yatsuyanagi
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Publication number: 20090156728Abstract: 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: ApplicationFiled: December 12, 2008Publication date: June 18, 2009Applicant: The Yokohama Rubber Co., Ltd.Inventors: Makoto Ashiura, Tetsuji Kawazura