The present disclosure relates to a modified conjugated diene-based polymer, a method for preparing the same and a rubber composition comprising the same, and the modified conjugated diene-based polymer has narrow molecular weight distribution, and includes S atoms in the specific content in the polymer, a derived unit from an N-containing aromatic hydrocarbon compound, a derived unit from an S-containing aromatic hydrocarbon compound or an S-containing heterocyclic compound.

The present disclosure relates to a modified conjugated diene-based polymer, a method for preparing the same and a rubber composition comprising the same, and the modified conjugated diene-based polymer has narrow molecular weight distribution, and includes S atoms in the specific content in the polymer, a derived unit from an N-containing aromatic hydrocarbon compound, a derived unit from an S-containing aromatic hydrocarbon compound or an S-containing heterocyclic compound.

A crosslinked rubber composition contains ethylene-propylene-diene copolymer rubber crosslinked with a rotaxane compound having a cyclic molecule and an axial molecule penetrating through the cyclic molecule. In the crosslinked rubber composition, the ethylene-propylene-diene copolymer rubber contains vinylnorbornene, dicyclopentadiene, or tetrahydroindene as a diene component, and the rotaxane compound has a nitrile oxide group on the cyclic molecule and one end of the axial molecule, and the cyclic molecule is crown ether.

A crosslinked rubber composition contains ethylene-propylene-diene copolymer rubber crosslinked with a rotaxane compound having a cyclic molecule and an axial molecule penetrating through the cyclic molecule. In the crosslinked rubber composition, the ethylene-propylene-diene copolymer rubber contains vinylnorbornene, dicyclopentadiene, or tetrahydroindene as a diene component, and the rotaxane compound has a nitrile oxide group on the cyclic molecule and one end of the axial molecule, and the cyclic molecule is crown ether.

A process for manufacturing a masterbatch comprises the following steps: (a) bringing at least one initial polymer comprising at least one carbon-carbon unsaturation into contact with at least one 1,3-dipolar grafting agent bearing at least one nitrile oxide dipole in the presence of at least one organophosphorus additive selected from the group consisting of phosphoric acid triesters, phosphonates, phosphinates, phosphine oxides and the mixtures of these compounds, and (b) recovering the masterbatch obtained in the preceding step. The masterbatch and compositions containing it and also tires comprising such compositions are also disclosed.

Provided are a rubber composition which provides a self-healing rubber with improved strength and wet grip performance, and a pneumatic tire including the rubber composition. The present disclosure relates to a rubber composition containing a rubber component having a functional group containing a cationic functional group and/or an anionic functional group, a filler capable of generating a charge paired with the functional group, and sulfur.

Provided are a rubber composition which provides a self-healing rubber with improved strength and wet grip performance, and a pneumatic tire including the rubber composition. The present disclosure relates to a rubber composition containing a rubber component having a functional group containing a cationic functional group and/or an anionic functional group, a filler capable of generating a charge paired with the functional group, and sulfur.

A tire having excellent wet grip performance and low rolling resistance is provided. This tire is a tire obtained by using a rubber composition that includes a rubber component containing a rubber having an isoprene structure and an aminoalkoxysilane-modified styrene-butadiene rubber having an amount of bonded styrene of 15% or less; a filler containing a silica having a nitrogen adsorption specific surface area (BET method) of 130 m.sup.2/g or more and less than 330 m.sup.2/g, the amount of the filler being 40 to 125 parts by mass with respect to 100 parts by mass of the rubber component; and a hydrogenated resin having a softening point of higher than 110° C. and having a weight average molecular weight as converted to polystyrene of 200 to 1200 g/mol, the amount of the hydrogenated resin being 5 to 50 parts by mass per 100 parts by mass of the rubber component.

The present invention relates to a modified conjugated diene-based polymer having excellent wet skid resistance and abrasion resistance in a balanced way, and a rubber composition comprising the same, and the modified conjugated diene-based polymer is characterized in including: a repeating unit derived from a conjugated diene-based monomer; and a functional group derived from a modifier, wherein, if measured by differential scanning calorimetry (DSC) through controlling the microstructure of the polymer, a difference between a glass transition onset temperature (T.sub.g-on) and a glass transition offset temperature (T.sub.g-off), which arise glass transition, is 10° C. to 30° C., thereby having excellent wet skid resistance and running resistance in a balanced way and improved effects of abrasion resistance, simultaneously.

This disclosure provides a rubber composition that can realize excellent low heat generating properties without deteriorating other performance. The rubber composition contains a rubber component and a filler, where the rubber component contains a conjugated diene-based polymer modified with a modifier containing a compound represented by the formula (1).

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