A run-flat tire has: a pair of bead cores; a carcass that straddles the pair of bead cores, and having end portions that are anchored on the bead cores; side reinforcing rubbers that are provided at tire side portions, and that extend in a tire radial direction along an inner surface of the carcass; a belt layer that is provided at an outer side, in a tire radial direction, of the carcass, and that is formed by covering a cord with resin; and a tread that is provided at an outer side, in a tire radial direction, of the belt layer.

A run-flat tire has: a pair of bead cores, each bead core formed by covering a wire with resin; a carcass that straddles the pair of bead cores, and having end portions that are anchored on the bead cores; side reinforcing rubbers that are provided at tire side portions, and that extend in a tire radial direction along an inner surface of the carcass; and a tread that is provided at an outer side, in a tire radial direction, of the carcass.

A run-flat tire has: a pair of bead cores; a carcass that straddles the pair of bead cores, and having end portions that are anchored on the bead cores; bead fillers that are made of resin and that extend from the bead cores along an outer surface of the carcass toward an outer side in a tire radial direction; and side reinforcing rubbers that are provided at tire side portions, and that extend in a tire radial direction along an inner surface of the carcass.

A modified conjugated diene-based polymer, and more particularly, a modified conjugated diene-based polymer prepared by continuous polymerization and having remarkable processability, narrow molecular weight distribution and excellent physical properties, and a rubber composition including the same.

A method for producing a rubber wet masterbatch comprises a step (i) of dispersing an inorganic filler into a dispersing solvent in the presence of a cellulose fiber to produce a slurry solution, a step (ii) of mixing the slurry solution and a rubber latex solution with each other to produce a slurry-containing rubber latex solution, and a step (iii) of solidifying and drying the slurry-containing rubber latex solution to produce the rubber wet masterbatch. The cellulose fiber has an average fiber diameter less than 1000 nm. When an amount of solid in the rubber latex solution blended in the step (ii) is regarded as 100 parts by mass, a blend amount of the cellulose fiber is from 0.1 to 50 parts by mass.

The present invention provides a tire improved in the run flat durability, having at least one member selected from the group consisting of a side reinforcing rubber layer and a bead filler using a rubber composition having a tensile stress at 50% elongation at 180 C. (M50) of 6.2 MPa or more as a vulcanized rubber physical property.

The present invention provides a tire improved in the run flat durability, having at least one member selected from the group consisting of a side reinforcing rubber layer and a bead filler using a rubber composition comprising a rubber component containing 20% by mass or more of a modified conjugated diene based polymer, satisfying Expression (1) in terms of the elongation X under a stress of 6.5 MPa at 180 C. and the elongation Y under a stress of 6.5 MPa at 25 C. after vulcanization.
1.00X/Y1.15(1)

The present invention provides: a rubber composition prepared by mixing 60 to 100 parts by mass of a filler (B), 0.9 to 2.4 parts by mass of a phenol resin (C), 0.07 to 0.2 parts by mass of a methylene donor (D), 1.5 to 2.1 parts by mass of a thiuram based vulcanization accelerating agent (E), and 3.2 to 4.5 parts by mass of a sulfenamide based vulcanization accelerating agent (F), based on 100 parts by mass of the rubber component comprising 20 to 80% by mass of a modified conjugated diene based polymer (A), allowing the ride comfort in normal running to be satisfied in parallel with improvement in the run flat durability (durability in run flat running); and a tire comprising at least one member selected from the group consisting of a side reinforcing rubber layer and a bead filler using the rubber composition.

To provide a method for producing a multicomponent copolymer with which a multicomponent copolymer having excellent rupture strength can be obtained, and a multicomponent copolymer, a rubber composition and a tire having excellent rupture strength. The method is a method for producing a multicomponent copolymer having a conjugated diene unit, a non-conjugated olefin unit and an aromatic vinyl unit, comprising adding a conjugated diene compound in divided portions into a reactor containing a catalyst and at least one selected from the group consisting of a non-conjugated olefin compound and an aromatic vinyl compound. The multicomponent copolymer is obtained with the production method. The rubber composition comprises the multicomponent copolymer as a rubber component. The tire uses the rubber composition.

A tire with improved wear resistance, rolling resistance and cohesion, comprises a rubber composition based on at least one elastomeric matrix comprising predominantly a random copolymer comprising ethylene units and conjugated diene units, the mole fraction of ethylene units in the copolymer being within a range extending from 50% to 95%; a peroxide; and a zinc diacrylate derivative in the form of a specific zinc salt; in which composition the contents of zinc diacrylate derivative and of peroxide being such that the ratio of the peroxide content to the zinc diacrylate derivative content is greater than or equal to 0.08; said composition comprising from 5 to less than 65 phr of reinforcing filler; the ratio of the filler content to the zinc diacrylate derivative content being greater than or equal to 1.25.