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 rubber composition having excellent low heat generating properties. The rubber composition of the present disclosure contains a rubber component, a filler containing silica, and a silane coupling agent, where the rubber component contains a conjugated diene-based polymer modified with a modifier containing a compound represented by the formula (1), and the silane coupling agent is a compound represented by the formula (2).

##STR00001##

Provided is a rubber composition having excellent low heat generating properties. The rubber composition of the present disclosure contains a rubber component, a filler containing silica, and a silane coupling agent, where the rubber component contains a conjugated diene-based polymer modified with a modifier containing a compound represented by the formula (1), and the silane coupling agent is a compound represented by the formula (2).

##STR00001##

The present invention relates to a modified conjugated diene-based polymer, a method for preparing the same and a rubber composition including the same, and relates to a modified conjugated diene-based polymer which is prepared by continuous polymerization and has excellent processability, a mooney large relaxation area of 300 MU-s to 1000 MU-s, and narrow molecular weight distribution, and if compounded into a rubber composition, shows improved tensile properties and viscoelasticity properties, particularly, a tan δ value at a high temperature (60° C.) among viscoelasticity properties, and excellent low hysteresis properties and fuel consumption properties, and a rubber composition including the same.

The present invention relates to a modified conjugated diene-based polymer, a method for preparing the same and a rubber composition including the same, and relates to a modified conjugated diene-based polymer which is prepared by continuous polymerization and has excellent processability, a mooney large relaxation area of 300 MU-s to 1000 MU-s, and narrow molecular weight distribution, and if compounded into a rubber composition, shows improved tensile properties and viscoelasticity properties, particularly, a tan δ value at a high temperature (60° C.) among viscoelasticity properties, and excellent low hysteresis properties and fuel consumption properties, and a rubber composition including the same.

Provided is a rubber composition that realizes excellent low heat generating properties while maintaining good steering stability when applied to a tire. The rubber composition of the present disclosure contains a rubber component containing a copolymer having a conjugated diene unit and an aromatic vinyl unit, and a filler, where the copolymer is a modified copolymer having a content of the aromatic vinyl unit of less than 10 mass % and modified with a modifier containing a compound represented by the formula (1).

##STR00001##

Provided is a rubber composition that realizes excellent low heat generating properties while maintaining good steering stability when applied to a tire. The rubber composition of the present disclosure contains a rubber component containing a copolymer having a conjugated diene unit and an aromatic vinyl unit, and a filler, where the copolymer is a modified copolymer having a content of the aromatic vinyl unit of less than 10 mass % and modified with a modifier containing a compound represented by the formula (1).

##STR00001##

The present invention relates to the use of N,N′,N″-substituted hexahydro-1,3,5-triazine in the anionic polymerization of conjugated diene monomer and vinylaromatic monomer. Use of this polar additive produces copolymers having both high vinylaromatic and low vinyl contents, while the blockiness of the vinylaromatic unit can be tailored.

The present invention relates to the use of N,N′,N″-substituted hexahydro-1,3,5-triazine in the anionic polymerization of conjugated diene monomer and vinylaromatic monomer. Use of this polar additive produces copolymers having both high vinylaromatic and low vinyl contents, while the blockiness of the vinylaromatic unit can be tailored.

The present disclosure provides a tire having excellent enduring performance. The present disclosure relates to a tire including a tread containing a rubber composition, the rubber composition satisfying the following relationships 1) to 3) when measured within 180 days after vulcanization: 1) Hso/Hsa×100≥95 wherein Hso: hardness at room temperature, Hsa: hardness at room temperature after heat treatment at 80° C. for 168 hours; 2) As/Ts×100≤70 wherein Ts: sulfur content before acetone extraction, As: sulfur content after acetone extraction; and 3) Swell≤330 wherein Swell: toluene swelling index.