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 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.

Provided is a thermoplastic elastomer composition which does not undergo viscosity increase during melt molding, gelation and molding failure, while having excellent heat resistance and durability. A thermoplastic elastomer composition for tires, which contains (A) an ethylene-vinyl alcohol copolymer or a modified ethylene-vinyl alcohol copolymer, (B) a thermoplastic resin or a thermoplastic elastomer, which has a melting point of 200° C. or higher, and (C) an acid-modified elastomer in an amount of 20% by volume or more based on the amount of all polymer components. This thermoplastic elastomer composition for tires is characterized in that if this thermoplastic elastomer composition for tires is extruded at a piston speed of 5 min/min at a temperature that is higher than the melting point of the thermoplastic resin or thermoplastic elastomer (B) by 20° C. in a viscosity measurement by means of a capillary rheometer, the viscosity η.sub.2 in 800 seconds after the start of the extrusion is less than 120% of the viscosity η.sub.1 in 200 seconds after the start of the extrusion.

Provided is a thermoplastic elastomer composition which does not undergo viscosity increase during melt molding, gelation and molding failure, while having excellent heat resistance and durability. A thermoplastic elastomer composition for tires, which contains (A) an ethylene-vinyl alcohol copolymer or a modified ethylene-vinyl alcohol copolymer, (B) a thermoplastic resin or a thermoplastic elastomer, which has a melting point of 200° C. or higher, and (C) an acid-modified elastomer in an amount of 20% by volume or more based on the amount of all polymer components. This thermoplastic elastomer composition for tires is characterized in that if this thermoplastic elastomer composition for tires is extruded at a piston speed of 5 min/min at a temperature that is higher than the melting point of the thermoplastic resin or thermoplastic elastomer (B) by 20° C. in a viscosity measurement by means of a capillary rheometer, the viscosity η.sub.2 in 800 seconds after the start of the extrusion is less than 120% of the viscosity η.sub.1 in 200 seconds after the start of the extrusion.

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.

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.

A copolymer of ethylene and a 1,3-diene, containing more than 50 mol % of ethylene units and containing 1,2-cyclohexanediyl units is provided. The 1,3-diene is 1,3-butadiene or a mixture of 1,3-dienes containing 1,3-butadiene, and the copolymer consists of a main chain and one or more side chains.

The invention relates to a process which responds to this problem scenario. The invention therefore relates to a process for preparing a rubber composition based on at least one diene elastomer, a reinforcing filler, a crumb rubber and a crosslinking system, said process comprising at least the following steps: incorporating the reinforcing filler into the diene elastomer, all at once or in several stages, and mixing; when the temperature of the mixture reaches a temperature of greater than 100° C., adding the crumb rubber; continuing the mixing up to a maximum temperature of between 120° C. and 190° C.; cooling the mixture to a temperature of less than 100° C.; incorporating the crosslinking system and mixing up to a maximum temperature of less than 110° C.

The invention discloses an iron bipyridine complex, a preparation method of the same, and use of the same in polymerization of conjugated dienes the invention provides an iron bipyridine complex, which is used as a primary catalyst showing high activity in the polymerization of polyprene to obtain a polymer with a high branched-chain degree. The polymer has the characteristics of a high molecular weight and narrow molecular weight distribution, and the molecular weight of the polymer can be adjusted by a chain transfer reagent. The obtained poly(conjugated diene) rubber has high branched-chain content and an ultrahigh molecular weight. Because there are a large number of side groups on the molecular chains of the rubber, the rubber is mainly used for preparing high-performance tires and other related rubber products with good wet traction and low friction-induced heat generation.

The present disclosure provides a tire which makes it possible to reduce the increase in hardness and the decrease in wet grip performance from before to after heat aging. The present disclosure relates to a tire including a tread, the tread including an elastomer composition containing a styrene elastomer and urethane particles, the tread satisfying the following relationship (1): (M100a−M100f)/M100f×100≤38 wherein M100f represents the stress at 100% elongation (23° C.) before heat aging, and M100a represents the stress at 100% elongation (23° C.) after heat aging.