The conjugated diene-based polymer has a Mooney viscosity measured at 100° C. of 40 or more and 170 or less, has Mooney stress relaxation measured at 100° C. of 0.35 or less, and has a branch number (Bn) measured by viscosity detector-equipped GPC-light scattering measurement of 8 or more.

The invention relates to a plasticizer system for use in a tread rubber composition. The plasticizer system is partially derived from or devoid of petroleum-based oils and resins. The pneumatic tire has a tread of a rubber composition comprising, based on 100 parts by weight of elastomer (phr): from about 10 to about 60 phr of a solution polymerized styrene-butadiene rubber (SSBR) extended with an oil not derived from petroleum; and a plasticizer system comprised of (1) from about 4 to about 8 phr of a plasticizing oil not derived from petroleum, and (2) from about 10 to about 20 phr of a hydrocarbon plasticizing resin selected from styrene/α-methyl styrene resin and polyterpene plasticizing resin.

This invention is based upon the unexpected finding that a hydrocarbon traction resin can be dispersed into the oil used in making an oil extended emulsion and solution rubbers to attain improved performance characteristics. For instance, this technique allows for the hydrocarbon traction resin to be incorporated into the rubber at a higher level than would ordinarily be possible using conventional mixing techniques. In tire tread compounds this provides improved wet traction characteristics without compromising cured stiffness (dry traction) and ultimate properties (chip/chunk resistance). This technique can be used to incorporate a resin into virtually any synthetic rubber that can benefit from being oil extended. It is of particular value in making resin modified solution styrene-butadiene rubber (SSBR), emulsion styrene-butadiene rubber (ESBR), high cis-1.4-polybutadiene rubber, and synthetic polyisoprene rubber which are formulated for use in tire tread compounds.

The present invention is directed to a pneumatic tire having a tread comprising a vulcanizable rubber composition comprising, based on 100 parts by weight of elastomer (phr), up to 100 phr of a solution polymerized styrene-butadiene rubber; from 5 to 50 phr of a fatty acid monoester of formula 1 ##STR00001##
where R.sup.1 is selected from C1 to C8 linear or branched alkyl, C1 to C8 linear or branched alkenyl, and C2 to C6 linear or branched alkyl substituted with from one to five hydroxyl groups; R.sup.2 is C11 to C21 alkyl or C11 to C21 alkenyl; from 5 to 50 phr of a hydrocarbon resin having a Tg ranging from −40° C. to 20° C.; less than 10 phr of a petroleum-derived oil; and from 50 to 130 phr of silica. optionally, from about 1 to 50 phr carbon black.

A rubber composition having an adhesion to a composition based on natural rubber, the composition being at least based on 5 to 95 phr of polyisoprene comprising a content by weight of 1,4-cis bonds of at least 90% of the weight of the polyisoprene; 5 to 95 phr of copolymer of ethylene and of a 1,3-diene of formula CH.sub.2═CR—CH═CH.sub.2, the ethylene units in the copolymer representing more than 50 mol % of the monomer units of the copolymer, the symbol R representing a hydrocarbon chain having 3 to 20 carbon atoms; and a crosslinking system. Also disclosed is a tire, in particular a tire provided with a sidewall, comprising this composition.

The present invention relates to compositions for elastomeric compounds for tyres, comprising polytetrazole cross-linking compounds characterized by precise activation temperatures, tyre components and tyres for vehicle wheels which comprise them. Advantageously, the present polytetrazole cross-linking agents give lower hysteresis and retention of the modulus of the compounds even under stress.

The present disclosure provides a functionalized carbon black obtained by treating an oxidized carbon black with a sulfur-containing primary or secondary amine or a salt thereof. The disclosure also relates to a process for preparing such functionalized carbon black. Furthermore, the present disclosure relates a vulcanizable rubber composition including (i) a vulcanizable rubber component, and (ii) an oxidized carbon black and (iii) a sulfur-containing primary or secondary amine or a salt thereof, or a functionalized carbon black formed from these components. The disclosure also concerns an article made from the vulcanizable rubber composition. The functionalized carbon blacks disclosed herein are particularly useful for obtaining rubber compounds with low hysteresis and enhanced abrasion resistance, e.g. for the production of energy-saving tires.

The present invention provides a run-flat tire excellent in run-flat durability. In the run-flat tire, a vulcanized rubber of a rubber composition containing a rubber component and a vulcanization accelerator that contains tetrabenzylthiuramdisulfide is used for at least one member selected from the group consisting of a side-reinforcing rubber layer and a bead filler. In the vulcanized rubber of the run-flat tire, a proportion of monosulfide bonds and disulfide bonds in all sulfide bonds is 65% or more.

This invention is based upon the unexpected finding that a hydrocarbon traction resin can be dispersed into the oil used in making an oil extended emulsion and solution rubbers to attain improved performance characteristics. For instance, this technique allows for the hydrocarbon traction resin to be incorporated into the rubber at a higher level than would ordinarily be possible using conventional mixing techniques. In tire tread compounds this provides improved wet traction characteristics without compromising cured stiffness (dry traction) and ultimate properties (chip/chunk resistance). This technique can be used to incorporate a resin into virtually any synthetic rubber that can benefit from being oil extended. It is of particular value in making resin modified solution styrene-butadiene rubber (SSBR), emulsion styrene-butadiene rubber (ESBR), high cis-1.4-polybutadiene rubber, and synthetic polyisoprene rubber which are formulated for use in tire tread compounds.

The present invention is directed to a benzoxazine-functionalized diene-based elastomer comprising polymer chains including repeat units which include conjugated diolefin monomers, such as 1,3-butadiene and isoprene. Additionally, said elastomer comprises at least one benzoxazine connected to a polymer chain via a spacer, wherein the spacer has a length ranging from 3 to 8 atoms. A further aspect of the present invention is directed to a rubber composition comprising such an elastomer, an article of manufacture comprising this rubber composition, and a method of making said benzoxazine-functionalized diene-based elastomer.