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.

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.

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.

The invention provides a heavy-duty tire rubber composition excellent in wet grip performance and steering stability, and a tire tread, a bead filler, a tire belt and a heavy-duty tire which each partially include the composition. The heavy-duty tire rubber composition includes 100 parts by mass of a solid rubber (A), 0.1 to 50 parts by mass of a modified liquid diene rubber (B) having a functional group derived from a silane compound with a specific structure, and 20 to 200 parts by mass of a filler (C), the modified liquid diene rubber (B) satisfying the following (i) and (ii): (i) the weight average molecular weight (Mw) is not less than 1,000 and not more than 120,000, and (ii) the vinyl content is not less than 30 mol % and less than 70 mol %.

The invention provides a heavy-duty tire rubber composition excellent in wet grip performance and steering stability, and a tire tread, a bead filler, a tire belt and a heavy-duty tire which each partially include the composition. The heavy-duty tire rubber composition includes 100 parts by mass of a solid rubber (A), 0.1 to 50 parts by mass of a modified liquid diene rubber (B) having a functional group derived from a silane compound with a specific structure, and 20 to 200 parts by mass of a filler (C), the modified liquid diene rubber (B) satisfying the following (i) and (ii): (i) the weight average molecular weight (Mw) is not less than 1,000 and not more than 120,000, and (ii) the vinyl content is not less than 30 mol % and less than 70 mol %.

Provided is a rubber composition having excellent adhesiveness to a metal member even if no cobalt salt is contained. The rubber composition contains a rubber component, a rubber-metal adhesion promoter containing Bi, and an organic acid salt of metal other than Bi, where a content of metal element other than Bi with respect to a content of Bi element (content of metal element other than Bi/content of Bi element) in the rubber composition is more than 14 and 100 or less in terms of molar ratio, a content of the rubber-metal adhesion promoter is more than 1.5 parts by mass with respect to 100 parts by mass of the rubber component, and the amount of substance of metal element other than Bi contained in the organic acid salt of metal other than Bi in the rubber composition is 0.01 mol or more.

Provided is a rubber composition having excellent adhesiveness to a metal member even if no cobalt salt is contained. The rubber composition contains a rubber component, a rubber-metal adhesion promoter containing Bi, and an organic acid salt of metal other than Bi, where a content of metal element other than Bi with respect to a content of Bi element (content of metal element other than Bi/content of Bi element) in the rubber composition is more than 14 and 100 or less in terms of molar ratio, a content of the rubber-metal adhesion promoter is more than 1.5 parts by mass with respect to 100 parts by mass of the rubber component, and the amount of substance of metal element other than Bi contained in the organic acid salt of metal other than Bi in the rubber composition is 0.01 mol or more.

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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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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