A vulcanizate is provided that includes a crosslinked network of elastomeric polymer having hydrogen bonds and covalent bonds. A method for preparing a functionalized elastomeric polymer and a method for preparing the vulcanizate are also provided.

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).

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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.

An object of the present invention is to provide a conveyor belt rubber composition having excellent wear resistance and gouging resistance, a method for producing the conveyor belt rubber composition, a conveyor belt formed using the conveyor belt rubber composition, and a belt conveyor equipped with the conveyor belt. The present invention relates to a conveyor belt rubber composition containing a diene rubber containing less than 50 mass % of an aromatic vinyl-conjugated diene copolymer, wherein the aromatic vinyl-conjugated diene copolymer has a content of repeating units derived from an aromatic vinyl of 20 mass % or less, and a proportion of a vinyl structure in repeating units derived from a conjugated diene of 8 mol % or less.

An object of the present invention is to provide a conveyor belt rubber composition having excellent wear resistance and gouging resistance, a method for producing the conveyor belt rubber composition, a conveyor belt formed using the conveyor belt rubber composition, and a belt conveyor equipped with the conveyor belt. The present invention relates to a conveyor belt rubber composition containing a diene rubber containing less than 50 mass % of an aromatic vinyl-conjugated diene copolymer, wherein the aromatic vinyl-conjugated diene copolymer has a content of repeating units derived from an aromatic vinyl of 20 mass % or less, and a proportion of a vinyl structure in repeating units derived from a conjugated diene of 8 mol % or less.

A method for producing a modified conjugated diene-based polymer includes polymerizing a monomer including a conjugated diene compound in the presence of an alkali metal compound or an alkali earth metal compound to obtain a polymer having an active terminal; (a modification) reacting the polymer having an active terminal with a compound [M] having a plurality of hydrocarbyloxysilyl groups to obtain a modified polymer; and a mixing the modified polymer with at least one compound [C] selected from a compound [N] having one hydrocarbyloxysilyl group and an alcohol having 6 to 20 carbon atoms.

Vulcanizates with desirable properties such as reduced hysteresis and improved wear resistance can be obtained from a composition that includes particulate filler(s) and at least two types of terminally functionalized polymers. One type of polymer has a heterocyclic moiety at a terminus, while another type has at one of its termini an aryl group that includes at least two hydroxyl substituents. The functionalized polymers are provided by reacting terminally active polymers with, respectively, a heterocyclic nitrile and a compound that includes an aryl group having at least two directly bonded OG.sub.p substituents, where G.sub.p is a protecting group, and a substituent that can react with the active terminus. The protecting groups can be removed so as to provide a terminal moiety that includes an aryl group having at least two directly bonded hydroxyl groups.

Vulcanizates with desirable properties such as reduced hysteresis and improved wear resistance can be obtained from a composition that includes particulate filler(s) and at least two types of terminally functionalized polymers. One type of polymer has a heterocyclic moiety at a terminus, while another type has at one of its termini an aryl group that includes at least two hydroxyl substituents. The functionalized polymers are provided by reacting terminally active polymers with, respectively, a heterocyclic nitrile and a compound that includes an aryl group having at least two directly bonded OG.sub.p substituents, where G.sub.p is a protecting group, and a substituent that can react with the active terminus. The protecting groups can be removed so as to provide a terminal moiety that includes an aryl group having at least two directly bonded hydroxyl groups.

The conjugated diene-based polymer has a Mooney viscosity measured at 100° C. of 40 or more and 170 or less, has Mooney stress relaxation measured at 100° C. of 0.35 or less, and has a branch number (Bn) measured by viscosity detector-equipped GPC-light scattering measurement of 8 or more.

A modifying agent, a modified conjugated diene polymer prepared using the same, a method for preparing a modified conjugated diene polymer, and a rubber composition including a modified conjugated diene polymer are disclosed herein. In some embodiments, a modifying agent comprises a compound represented by formula 1. The modifying agent is capable of improving processability of a rubber composition including the polymer prepared using the modifying agent. Fuel consumption properties of a car using tires including the rubber composition may be improved.