Provided are a rubber composition having excellent overall performance in terms of fuel economy and bleed resistance as well as good LCA performance (e.g., reduction of CO.sub.2 emissions), and a tire including the composition. A rubber composition containing a plant oil satisfying the conditions (1)-(4): (1) it is liquid at 23° C.; (2) it has a GPC weight-average molecular weight of more than 800; (3) when it is 3-fold diluted with THF, it satisfies the following relationship with respect to the absorbances at 450 nm and 600 nm measured with a spectrophotometer: Absorbance at 450 nm−Absorbance at 600 nm 0.05; and (4) it satisfies the following relationship with respect to the weights before and after passing 100 g of the plant oil at 23-30° C. through 20 mesh plain weave wire cloth: (Weight after passing through plain weave wire cloth)/(Weight before passing through plain weave wire cloth)×100≥99.0.

A tire sidewall comprising a vulcanized rubber and a polymeric organo silicon compound.

A modified conjugated diene rubber having a modifying structure derived from a siloxane compound at at least one terminal of a polymer chain containing conjugated diene monomer unit and a monomer unit of a vinyl compound having a functional group interactive with silica.

A rubber composition, which exhibits an improved fatigue strength and stiffness performance compromise, is based on at least one elastomer matrix containing at least one polyisoprene and at least one copolymer containing ethylene units and diene units; a paraffin oil having a glass transition temperature of less than -75° C.; a reinforcing filler comprising carbon black; and a crosslinking system, in which the at least one polyisoprene and the at least one copolymer containing ethylene units and diene units represent more than 40% by weight of the elastomer matrix.

The present disclosure provides a tire in which cracks or other defects on the surface of a tire component can be reduced to provide an excellent market life. A tire including a rubber layer and satisfying the following relationships (1) and (2): E1/E2×100>25 (1); and E1/E2×T×100>50 (2) wherein E1 denotes the fracture energy (MPa.Math.%) determined by cutting a No. 7 dumbbell-shaped specimen cut out of the rubber layer, heat-treating the specimen with the cut sections attached to each other at 170° C. for 12 minutes, and then stretching and deforming the specimen; E2 denotes the fracture energy (MPa.Math.%) determined by heat-treating a No. 7 dumbbell-shaped specimen cut out of the rubber layer at 170° C. for 12 minutes and then stretching and deforming the specimen; and T denotes the thickness (mm) of the rubber layer.

A color rubber composition for tires according to an embodiment contains a rubber component, a pigment other than black or white, a petroleum wax, and a white filler. The petroleum wax has a normal/iso ratio (mass ratio) of 70/30 to 90/10. The carbon number distribution for iso components in the whole petroleum wax is 1.0% or less for 25 or less carbon atoms, 4.0 to 8.0% for 26 to 32 carbon atoms, 5.0 to 15.0% for 33 to 44 carbon atoms, and 1.0% or more for 45 or more carbon atoms. The carbon number distribution for normal components in the whole petroleum wax is 5.0 to 18.0% for 25 or less carbon atoms, 40.0 to 48.0% for 26 to 32 carbon atoms, 15.0 to 27.5% for 33 to 44 carbon atoms, and 2.0% or more for 45 or more carbon atoms.

A tire has an outer sidewall, said outer sidewall comprising a rubber composition based on at least one or more diene elastomers, an anti-ozone wax in a content of greater than 8 phr, a reinforcing filler in a content of between 30 and 75 phr, a plasticizer that is liquid at 23° C. in a content of between 5 and 40 phr, and a crosslinking system. This composition has the advantage of being highly resistant to external physical attacks.

The present invention relates to a method for the preparation of a synthetic rubber blend, wherein the blend comprises a high molecular weight polydiene (A) and a low molecular weight polydiene (B). The present invention further relates to a synthetic rubber blend obtainable according to the method described herein; as well as to rubber compositions comprising the blend; and articles, such as tires.

Provided is a pneumatic tire that has excellent fuel efficiency and rubber strength and combines high load capacity and space saving. A pneumatic tire mounted on a vehicle, comprises: a tread configured to come into contact with a road surface; and a belt layer located on an inner side of the tread in a tire radial direction, wherein an outer diameter of the pneumatic tire is 350 mm or more and 600 mm or less, the following relationship:

0.78≤RW/SW≤0.88 is satisfied, where RW is a rim width of a rim wheel to be attached to the pneumatic tire and SW is a tire section width of the pneumatic tire, and a rubber composition that contains: a rubber component containing a diene-based rubber; and a mercaptocarboxylic acid compound is used in the pneumatic tire.

In a pneumatic tire in which a reinforcing layer including a cord is embedded, a coating rubber covering the cord included in the reinforcing layer uses a rubber composition in which 30 parts by mass to 60 parts by mass of carbon black having a nitrogen adsorption specific surface area N.sub.2SA of 100 m.sup.2/g or more and 0 parts by mass or more and 10 parts by mass or less of aroma oil is optionally blended, per 100 parts by mass of a rubber component containing 70 mass % to 100 mass % of a natural rubber and in which a strength at break TB (unit: MPa) at 100° C. and a stress M100 (unit: MPa) at 100% elongation at 100° C. satisfy a relationship TB.sup.2/M100≥50.0.