The present invention relates to a rubber composition having excellent tensile properties and viscoelasticity properties and including a conjugated diene-based polymer. The rubber composition may include a modified conjugated diene-based polymer which is selected considering target tensile properties and viscoelasticity properties, by predicting in advance the correlation between the modification ratio of the modified conjugated diene-based polymer and the dynamic viscoelasticity loss coefficient at 60° C. of the rubber composition through Mathematical Formula 1 and Mathematical Formula 2. Therefore, excellent compounding properties may be shown.

The invention relates to a method of manufacturing conjugated diene-based polymers. The conjugated diene-based polymers are obtained by polymerizing conjugated diene monomers or conjugated diene monomers and vinyl aromatic monomers using an initiator, wherein the initiator is obtained by reacting a divinylarene-like compound represented by the formula (1) with an organic alkali metal; A and B are C.sub.nH.sub.2n+1 or an aromatic ring, n is 0~5, A and B can be the same or different, and Q is an aromatic ring; wherein the molar ratio of the divinylarene-like compound to the effective active organic alkali metal is 1.3-5.0. The present invention further relates to a rubber comprising the conjugated diene-based polymers, and a tire comprising the rubber.

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A sulfur-vulcanizable rubber compound comprises a silane functionalized diene elastomer, a silane coupling agent, and a silica filler. The silane coupling agent excludes an active sulfur moiety. The rubber compound is a reaction product of a siloxyl condensation reaction between the silane functionalized diene elastomer and the non-sulfur containing silane coupling agent. The coupling agent comprises at least one end terminating group reactive with a hydroxyl group contained on the silica filler and a silane moiety contained on a diene-based elastomer.

Disclosed are a method of preparing a modified conjugated diene-based polymer, a modified conjugated diene-based polymer prepared thereby, a rubber composition including the modified conjugated diene-based polymer, and a tire including the rubber composition. The method of preparing the modified conjugated diene-based polymer includes (a) polymerizing a vinyl aromatic monomer and a conjugated diene monomer through continuous solution polymerization using a multifunctional anionic polymerization initiator in the presence of a hydrocarbon solvent, thus forming an active polymer having a reactive end; and (b) coupling or linking the reactive end of the active polymer with an alkylamino alkoxy silane compound.

Disclosed are a method of preparing a modified conjugated diene-based polymer, a modified conjugated diene-based polymer prepared thereby, a rubber composition including the modified conjugated diene-based polymer, and a tire including the rubber composition. The method of preparing the modified conjugated diene-based polymer includes (a) polymerizing a vinyl aromatic monomer and a conjugated diene monomer through continuous solution polymerization using a multifunctional anionic polymerization initiator in the presence of a hydrocarbon solvent, thus forming an active polymer having a reactive end; and (b) coupling or linking the reactive end of the active polymer with an alkylamino alkoxy silane compound.

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 objective of the present invention is to provide a derivative of polybutadiene suitable as a material of a curable composition for obtaining a cured product having high shearing stress. The present invention provides: a silylated polybutadiene characterized by containing a repeating unit represented by formula (I) (in the formula: R.sup.1, R.sup.2, and R.sup.3 each independently represents an unsubstituted or substituted aryl group, an alkyl group, or an aralkyl group. Among R.sup.1 to R.sup.3, at least one of R.sup.1 to R.sup.3 is an aryl group or aralkyl group); a curable composition characterized by containing the silylated polybutadiene and a polymerization initiator; and a cured product obtained by curing the curable composition. ##STR00001##

The objective of the present invention is to provide a derivative of polybutadiene suitable as a material of a curable composition for obtaining a cured product having high shearing stress. The present invention provides: a silylated polybutadiene characterized by containing a repeating unit represented by formula (I) (in the formula: R.sup.1, R.sup.2, and R.sup.3 each independently represents an unsubstituted or substituted aryl group, an alkyl group, or an aralkyl group. Among R.sup.1 to R.sup.3, at least one of R.sup.1 to R.sup.3 is an aryl group or aralkyl group); a curable composition characterized by containing the silylated polybutadiene and a polymerization initiator; and a cured product obtained by curing the curable composition. ##STR00001##

This invention is based upon the unexpected finding that the reaction product of polyisobutylene and a silane can be incorporated into tire sealant formulations to greatly reduce the level of hysteresis exhibited by such sealant formulations which decreases the rolling resistance of the tire to improve fuel economy. This is made possible by the further unexpected fining that silanes will react with polyisobutylene by a reaction which is initiated with a peroxide. This invention more specifically discloses a sealant composition which is particularly useful in manufacturing self-sealing tires and which is comprised of (a) the reaction product of polyisobutylene and a silane; and (b) a reinforcing filler. The sealant compositions also contain a peroxide to facilitate partial degradation of the polyisobutylene rubber during the curing of the tire.

This invention is based upon the unexpected finding that the reaction product of polyisobutylene and a silane can be incorporated into tire sealant formulations to greatly reduce the level of hysteresis exhibited by such sealant formulations which decreases the rolling resistance of the tire to improve fuel economy. This is made possible by the further unexpected fining that silanes will react with polyisobutylene by a reaction which is initiated with a peroxide. This invention more specifically discloses a sealant composition which is particularly useful in manufacturing self-sealing tires and which is comprised of (a) the reaction product of polyisobutylene and a silane; and (b) a reinforcing filler. The sealant compositions also contain a peroxide to facilitate partial degradation of the polyisobutylene rubber during the curing of the tire.