Provided is a pneumatic tire including a tread formed from a rubber composition highly improving wet-grip performance, dry-grip performance, and durability while maintaining a good balance therebetween. A pneumatic tire including a tread formed from a rubber composition, the composition containing 90% by mass or more of a diene rubber per 100% by mass of the rubber component, the composition further containing a hydrogenated terpene aromatic resin obtained by hydrogenation of double bonds of a terpene aromatic resin, the hydrogenated terpene aromatic resin having a degree of hydrogenation of double bonds of 5-100% and a hydroxyl value of 20 mg KOH/g or less, the hydrogenated terpene aromatic resin being present in an amount of 1-50 parts by mass per 100 parts by mass of the diene rubber, the composition further containing specific inorganic filler in an amount of 1-70 parts by mass per 100 parts by mass of the diene rubber.

The present invention is to provide: a rubber composition which has excellent wet grip performance and also has excellent wear resistance while maintaining high elongation; and a pneumatic tire and a conveyer belt each of which is manufactured using the rubber composition. The present invention provides: a rubber composition containing a modified diene rubber, in the modified rubber, from 0.02 to 4 mol % of double bonds contained in a diene rubber being modified into hydroxy groups by reacting at least one type of diene rubber selected from the group consisting of styrene butadiene rubbers, butadiene rubbers, and nitrile butadiene rubbers with a hydroxy group-containing nitrone compound having both a hydroxy group and a nitrone group; and a pneumatic tire and a conveyer belt each of which is manufactured using the rubber composition.

The present invention is to provide: a rubber composition which has excellent wet grip performance and also has excellent wear resistance while maintaining high elongation; and a pneumatic tire and a conveyer belt each of which is manufactured using the rubber composition. The present invention provides: a rubber composition containing a modified diene rubber, in the modified rubber, from 0.02 to 4 mol % of double bonds contained in a diene rubber being modified into hydroxy groups by reacting at least one type of diene rubber selected from the group consisting of styrene butadiene rubbers, butadiene rubbers, and nitrile butadiene rubbers with a hydroxy group-containing nitrone compound having both a hydroxy group and a nitrone group; and a pneumatic tire and a conveyer belt each of which is manufactured using the rubber composition.

A pneumatic tire that specifies the tire mounting direction when mounted on a vehicle and has sufficiently improved grip performance at high-speed turning is provided in which the cap rubber layer on the outermost layer of the tread is divided in the tire width direction, the cap rubber layer located on the outside of the vehicle is formed of a rubber composition containing 25% by mass or less of styrene in the rubber component and having a glass transition temperature of −18° C. or higher, and, when the carbon black content ratio is C.sub.OUT (mass %), and the ground contact area ratio is L.sub.OUT, in the cap rubber layer located on the outside of the vehicle, and the carbon black content ratio is C.sub.IN (mass %) and the ground contact area ratio is L.sub.IN in the cap rubber layer located inside the vehicle, the following (Formula 1) and (Formula 2) are satisfied.

C.sub.IN<C.sub.OUT  (Formula 1)

0≤(C.sub.OUT×L.sub.OUT)−(C.sub.IN×L.sub.IN)  (Formula 2)

A functionalized elastomer comprising the reaction product of a living elastomeric polymer and a polymerization terminator of formula I
[R.sup.1].sub.n—B—[X—R.sup.2].sub.m  I
where B is boron; X is oxygen or nitrogen; R.sup.1 is independently vinyl, oxiranyl, phenyl, 1-alkenyl of 2 to 8 carbon atoms, alkyl of 1 to 8 carbon atoms including at least one halogen atom, 1-alkenyl of 2 to 8 carbon atoms including at least one halogen or one hydrogen; R.sup.2 is independently C1 to C8 alkyl, C8 to C14 aryl; or when m>1 R.sup.2 may be taken together to form a substituted or unsubstituted cyclic structure comprising 2 to 16 carbon atoms where the cyclic structure may be heterocyclic or non-heterocyclic; n is 1 or 2, m is 1 or 2, and n+m=3.

A functionalized elastomer comprising the reaction product of a living elastomeric polymer and a polymerization terminator of formula I
[R.sup.1].sub.n—B—[X—R.sup.2].sub.m  I
where B is boron; X is oxygen or nitrogen; R.sup.1 is independently vinyl, oxiranyl, phenyl, 1-alkenyl of 2 to 8 carbon atoms, alkyl of 1 to 8 carbon atoms including at least one halogen atom, 1-alkenyl of 2 to 8 carbon atoms including at least one halogen or one hydrogen; R.sup.2 is independently C1 to C8 alkyl, C8 to C14 aryl; or when m>1 R.sup.2 may be taken together to form a substituted or unsubstituted cyclic structure comprising 2 to 16 carbon atoms where the cyclic structure may be heterocyclic or non-heterocyclic; n is 1 or 2, m is 1 or 2, and n+m=3.

The present invention relates to a modifier represented by Formula 1, a method of preparing the same, a modified conjugated diene-based polymer having a high modification ratio which includes a modifier-derived functional group, and a method of preparing the polymer.

The present invention relates to a modifier represented by Formula 1, a method of preparing the same, a modified conjugated diene-based polymer having a high modification ratio which includes a modifier-derived functional group, and a method of preparing the polymer.

The purpose of the present invention is to provide a modified polymer that significantly reduces heat build-up due to the modification when the modified polymer is formed into a rubber composition, a rubber composition containing the modified polymer, and a pneumatic tire in which the rubber composition is used. The modified polymer of the present invention is a modified polymer obtained by modifying a styrene-conjugated diene copolymer (A) with a nitrone compound (B). In the modified polymer, the content of styrene units in the styrene-conjugated diene copolymer (A) is 10% by mass or greater, and the proportion of vinyl bonds among all the double bonds contained in the styrene-conjugated diene copolymer (A) is 5 mol % or greater.

The purpose of the present invention is to provide a modified polymer that significantly reduces heat build-up due to the modification when the modified polymer is formed into a rubber composition, a rubber composition containing the modified polymer, and a pneumatic tire in which the rubber composition is used. The modified polymer of the present invention is a modified polymer obtained by modifying a styrene-conjugated diene copolymer (A) with a nitrone compound (B). In the modified polymer, the content of styrene units in the styrene-conjugated diene copolymer (A) is 10% by mass or greater, and the proportion of vinyl bonds among all the double bonds contained in the styrene-conjugated diene copolymer (A) is 5 mol % or greater.