Abstract: A tire includes block rows delimited by a pair of circumferential grooves extending in a tire circumferential direction. The block rows include a plurality of blocks partitioned by a plurality of lateral grooves extending in a tire width direction, and each block is partitioned into a plurality of small blocks by a circumferential sipe extending in the tire circumferential direction and a plurality of lateral sipes. The lateral sipes include a first lateral sipe and a second lateral sipe extending in different directions.
Abstract: This invention relates to a method for producing a copolymer of a conjugated diene compound and an unconjugated olefin other than the conjugated diene compound having a high cis-1,4 bond content of a conjugated diene compound portion, and more particularly to a method for producing a copolymer characterized by comprising a step of polymerizing a conjugated diene compound and an unconjugated olefin other than the conjugated diene compound in the presence of a polymerization catalyst composition including at least one complex selected from a metallocene complex represented by the following general formula (I): (wherein M is a lanthanoid element, scandium, or yttrium, and CpR is independently a non-substituted or substituted indenyl, and Ra-Rf are independently an alkyl group having a carbon number of 1-3 or a hydrogen atom, and L is a neutral Lewis base, and w is an integer of 0-3) and so on.
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.
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