To provide a rubber composition excellent in fracture characteristics while maintaining hardness, and to provide a pneumatic tire using the same. The rubber composition contains a diene-based rubber, and 0.1 to 10 parts by mass of a thioester-based compound represented by the general formula (1) (each A is an alkyl group or aromatic having 1 to 10 carbon atoms, and may be the same or different, and n is an integer of 1 to 6) with respect to 100 parts by mass of the diene-based rubber.

A—COS— (CH.sub.2) .sub.n—SCO—A

To provide a pneumatic tire in which the rolling resistance coefficient is reduced while maintaining steering stability. A total gauge TOGa of a cap tread rubber (11A) and an undertread rubber (11B) and a gauge UTGa of the undertread rubber (11B) satisfy a relationship 0.20 ≤ UTGa/TOGa ≤ 0.40 in a ground contact region defined by a pair of shoulder main grooves (10B) located on both outermost sides in a tire width direction in a tread portion (1). A hardness UTHs of the undertread rubber (11B) is in a range of 62 or more and 67 or less. The hardness UTHs of the undertread rubber (11B) and a hardness CapHs of the cap tread rubber (11A) satisfy a relationship 0.90 ≤ CapHs/UTHs ≤ 1.20. A tan δ (60° C.) of the undertread rubber (11B) is less than 0.06.

A tire tread composition includes a quantity of an elastomer including guayule natural rubber, and a quantity of a hydrocarbon resin substantially evenly distributed throughout the elastomer. The elastomer of the tire tread composition may consist entirely of guayule natural rubber. The hydrocarbon resin may be selected to have a predetermined miscibility in the guayule natural rubber. The predetermined miscibility is measured by a deviation of actual Tg from predicted Tg for either the tire tread composition or an elastomer-resin mixture consistent with the elastomer and resin used in the tire tread composition. In particular, the predetermined miscibility in the guayule natural rubber is less than about six percent (6%) deviation in the actual Tg from the predicted Tg at a 20 phr loading.

Compounds having an elastomer material, a filler material, at least one additive material, and at least one accelerant material are disclosed. In various embodiments, the filler material comprises a graphene-based carbon material. In various embodiments, the graphene-based carbon material comprises graphene comprising up to 15 layers, carbon aggregates having a median size from 1 to 50 microns, a surface area of the carbon aggregates at least 50 m.sup.2/g, when measured via a Brunauer-Emmett-Teller (BET) method with nitrogen as the adsorbate, and no seed particles.

The present disclosure provides methods for producing an olefin polymer by contacting a C.sub.3-C.sub.40 olefin, ethylene and a diene with a catalyst system including an activator and a metallocene catalyst compound comprising a substituted or unsubstituted indacenyl group and obtaining a C.sub.3-C.sub.40 olefin-ethylene-diene terpolymer typically comprising from 30 to 55 mol % ethylene, from 69.09 to 45 mol % C.sub.3 to C.sub.40 comonomer, and from 0.01 to 7 mol % diene wherein the Tg of the terpolymer is −28° C. or less. Preferably, a propylene-ethylene-ethylidene norbornene is obtained.

A curable rubber composition comprises: a rubber component in an amount of 100 PHR; at least one filler in an amount from 10 to 110 PHR;
characterized in that said curable rubber composition comprises alpha-tocopherol as an extractable residue from banana peels in an amount from 0.1 to 15 PHR.

The curable rubber composition may also further comprise a curative package in an amount from 0.5 to 15 PHR. Also disclosed is a cross-linked rubber composition obtained by cross-linking such a rubber composition, and a method of preparing a tyre, and a tyre.

Nanocellulose dispersion compositions containing a partitioning agent and a nanocellulose, and methods of making the nanocellulose dispersion compositions, are disclosed. These nanocellulose dispersion compositions can be used in tire formulations with carbon black and a suitable elastomer to produce articles of manufacture for use in tire and tread applications.

A pneumatic tire having a tread reinforcing component disposed between a tire inner cavity surface and a tire ground contacting surface, and made of a thermoplastic resin. On an arbitrary reference line which extends across the tread reinforcing component in parallel with the tire equator, a distance L1 in the tire radial direction from the tire inner cavity surface to the thickness center point of the tread reinforcing component is in a range of 50% to 95% of a distance L0 in the tire radial direction from the tire inner cavity surface to the tire ground contacting surface.

Provided is a rubber composition for base tread which can provide excellent steering stability and rolling resistance and improve pass-by noise properties when applied to a tire. The present disclosure discloses a rubber composition for base tread to be used for base tread of a tread portion of a tire, where a ratio of storage modulus at 0° C. (0° C. E′) to storage modulus at 30° C. (30° C. E′) (0° C. E′/30° C. E′) is in a range of 1.3 to 2.0.

A rubber composition is prepared by mixing a specific hydrazide compound at a ratio of 0.5 to 3.0 parts by mass, zinc oxide at a ratio of 1 to 5 parts by mass, and carbon black having N.sub.2SA of 60 to 150 m.sup.2/g at a ratio of 30 to 60 parts by mass per 100 parts by mass of diene rubber containing 80 parts by mass or more of natural rubber. The rubber composition is prepared through (a) mixing the hydrazide compound and the carbon black to obtain a mixture, and (b) mixing the zinc oxide with the mixture obtained in step (a) to obtain a mixture. A maximum ultimate temperature during the mixture in step (a) is from 140 to 170° C. A storage modulus and elongation at break have a specific relationship.