Patents by Inventor Yasushi Hamura

Yasushi Hamura 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: 8835566
    Abstract: The present invention provides a vulcanized rubber material having improved heat resistance while maintaining ozone resistance of an epihalohydrin rubber, and a rubber composition for vulcanization for producing the same. The invention further provides a vulcanized rubber material and a rubber composition for vulcanization, that can achieve the above objects without using an organonickel compound having a concern about toxicity, or if used, using the same as less as possible. The present invention relates to a rubber composition for vulcanization comprising (a) 100 parts by weight of an epihalohydrin rubber, (b) 0.01 to 0.5 part by weight of a copper salt of dithiocarbamic acid, (c) an acid acceptor, and (d) a polythiol type vulcanizing agent or a polyol type vulcanizing agent, a vulcanized rubber material obtained by vulcanizing the composition, and an automotive rubber part comprising the vulcanized rubber material.
    Type: Grant
    Filed: October 26, 2007
    Date of Patent: September 16, 2014
    Assignee: Daiso Co., Ltd.
    Inventors: Shigeru Shoji, Toyofumi Otaka, Toshiyuki Funayama, Yasushi Hamura
  • Patent number: 8283039
    Abstract: The invention provides a vulcanized rubber laminate obtained by firmly bonding an unvulcanized epichlorohydrin rubber layer and an organic peroxide-containing fluororubber layer. The laminate is obtained by thermal adhesion a layer of an unvulcanized epichlorohydrin rubber composition to a layer of an unvulcanized fluororubber composition. The epichlorohydrin rubber composition comprises 1) an unvulcanized epichlorohydrin rubber containing 3 to 15 mol % of allyl glycidyl ether unit, 2) quinoxaline-based vulcanizing agents, mercaptotriazine-based vulcanizing agents or bisphenol-based vulcanizing agents, and 3) 1,8-diazabicyclo(5,4,0)undecene-7 salts, 1,5-diazabicyclo(4,3,0)nonene-5 salts, quaternary ammonium salts, quaternary phosphonium salts, basic white carbons or an alkaline metal salt of higher fatty acid the fluororubber composition comprises an fluororubber and an organic peroxide-based vulcanizing agent.
    Type: Grant
    Filed: March 24, 2006
    Date of Patent: October 9, 2012
    Assignee: Daiso Co., Ltd.
    Inventors: Toshiyuki Funayama, Shigeru Shoji, Yasushi Hamura, Toyofumi Otaka
  • Patent number: 8258222
    Abstract: A composition for epihalohydrin vulcanized rubber excellent in heat resistance while keeping good vulcanization rate and store stability, comprising (a) an epihalohydrin robber, (b) a metal soap, (c) an acid acceptor, and (d) a vulcanizing agent, the composition further preferably containing (e) a fatty acid for suppressing vulcanization, or preferably containing (f) an alcohol for accelerating vulcanization.
    Type: Grant
    Filed: November 23, 2005
    Date of Patent: September 4, 2012
    Assignee: Daiso Co., Ltd.
    Inventors: Toyofumi Otaka, Shigeru Shoji, Yasushi Hamura, Toshiyuki Funayama
  • Publication number: 20110160344
    Abstract: The present invention provides a vulcanized rubber material having improved heat resistance while maintaining ozone resistance of an epihalohydrin rubber, and a rubber composition for vulcanization for producing the same. The invention further provides a vulcanized rubber material and a rubber composition for vulcanization, that can achieve the above objects without using an organonickel compound having a concern about toxicity, or if used, using the same as less as possible. The present invention relates to a rubber composition for vulcanization comprising (a) 100 parts by weight of an epihalohydrin rubber, (b) 0.01 to 0.5 part by weight of a copper salt of dithiocarbamic acid, (c) an acid acceptor, and (d) a polythiol type vulcanizing agent or a polyol type vulcanizing agent, a vulcanized rubber material obtained by vulcanizing the composition, and an automotive rubber part comprising the vulcanized rubber material.
    Type: Application
    Filed: October 26, 2007
    Publication date: June 30, 2011
    Applicant: Daisco Co. Ltd
    Inventors: Shigeru Shoji, Toyofumi Otaka, Toshiyuki Funayama, Yasushi Hamura
  • Publication number: 20090023889
    Abstract: An object of the invention is to provide a process for producing an ether (co)polymer in which molecular weight control is easy and post treatment of the reaction liquid after polymerization (solvent recovery, etc.) is easy; a chain transfer agent to be used in the production process; and an ether (co) polymer obtained according to the production process. The process for producing an ether (co) polymer of the invention is characterized in that an ether monomer is polymerized in a solvent, in the presence of a catalyst comprising a condensate of an organotin compound and an alkyl phosphate, and a chain transfer agent comprising, as the major ingredient thereof, an aliphatic polyalcohol of the following general formula (I), thereby producing an ether (co)polymer. Cx(OH)yHz. In the formula, X indicates an integer of from 2 to 8; Y indicates an integer of from 2 to (2X+2); Z indicates an integer of 2X+2?Y; and the hydroxyl groups are bonded at any positions.
    Type: Application
    Filed: June 1, 2006
    Publication date: January 22, 2009
    Applicant: DAISCO CO., LTD.
    Inventors: Kozo Misumi, Yutaka Shiomi, Shigeru Shoji, Yasushi Hamura
  • Publication number: 20060216518
    Abstract: The invention provides a vulcanized rubber laminate obtained by firmly bonding an unvulcanized epichlorohydrin rubber layer and an organic peroxide-containing fluororubber layer. The laminate is obtained by thermal adhesion a layer of an unvulcanized epichlorohydrin rubber composition to a layer of an unvulcanized fluororubber composition. The epichlorohydrin rubber composition comprises 1) an unvulcanized epichlorohydrin rubber containing 3 to 15 mol % of allyl glycidyl ether unit, 2) quinoxaline-based vulcanizing agents, mercaptotriazine-based vulcanizing agents or bisphenol-based vulcanizing agents, and 3) 1,8-diazabicyclo(5,4,0)undecene-7 salts, 1,5-diazabicyclo(4,3,0)nonene-5 salts, quaternary ammonium salts, quaternary phosphonium salts, basic white carbons or an alkaline metal salt of higher fatty acid the fluororubber composition comprises an fluororubber and an organic peroxide-based vulcanizing agent.
    Type: Application
    Filed: March 24, 2006
    Publication date: September 28, 2006
    Applicant: DAISO CO., LTD.
    Inventors: Toshiyuki Funayama, Shigeru Shoji, Yasushi Hamura, Toyofumi Otaka
  • Publication number: 20060128857
    Abstract: A composition for epihalohydrin vulcanized rubber excellent in heat resistance while keeping good vulcanization rate and store stability, comprising (a) an epihalohydrin robber, (b) a metal soap, (c) an acid acceptor, and (d) a vulcanizing agent, the composition further preferably containing (e) a fatty acid for suppressing vulcanization, or preferably containing (f) an alcohol for accelerating vulcanization.
    Type: Application
    Filed: November 23, 2005
    Publication date: June 15, 2006
    Applicant: DAISO CO., LTD.
    Inventors: Toyofumi Otaka, Shigeru Shoji, Yasushi Hamura, Toshiyuki Funayama