Patents Assigned to Bridgestone Corportion
  • Patent number: 5765355
    Abstract: A steel cord is disclosed, which has a core-sheath double layer structure having a 2+7 cord construction or a 2+8 cord construction. A twisting direction of the core is the same as that of the sheath, a forming rate Rc of filaments of the core is 103 to 120%, and a forming rate Rs of filaments of the sheath is 102 to 115%. A pneumatic radial tire using such steel cords in a belt layer is also disclosed.
    Type: Grant
    Filed: September 5, 1996
    Date of Patent: June 16, 1998
    Assignee: Bridgestone Corportion
    Inventors: Manabu Yanagisawa, Kiyoshi Ikehara
  • Patent number: 5420219
    Abstract: A vulcanizable elastomeric compound and products such as pneumatic tires and the like, are formed from a functionalized polymer having a functional group derived from an anionic polymerization initiator. The anionic polymerization initiator comprises the general formula ##STR1## where R.sup.1 -R.sup.5 are the same or different and are selected from the group consisting of hydrogen; alkyls having from alkyls having from 1 to about 12 carbon atoms; aralkyls having from 7 to about 20 carbon atoms; dialkylaminos having from 2 to about 20 carbon atoms; and, dialkylaminoalkyls having from 3 to about 20 carbon atoms. At least one of R.sup.1 -R.sup.5 is selected from the group consisting of the dialkylaminos and the dialkylaminoalkyls. Methods of the present invention include preparing functionalized polymers and reducing the hysteresis of vulcanizable elastomeric compounds.
    Type: Grant
    Filed: August 10, 1993
    Date of Patent: May 30, 1995
    Assignee: Bridgestone Corportion
    Inventors: David F. Lawson, Thomas A. Antkowiak, Mark L. Stayer, Jr., John R. Schreffler, Hideki Komatsu
  • Patent number: D369766
    Type: Grant
    Filed: March 17, 1995
    Date of Patent: May 14, 1996
    Assignee: Bridgestone Corportion
    Inventors: Masamichi Wakamatsu, Yasuhiro Hamada