A rubber composition for a tire, which does not require the addition of a compound when synthesizing rubber component and the modification of a rubber component, and a winter tire using the rubber composition are provided. The rubber composition for a tire contains fine particles of rotaxane having a straight chain molecule, acyclic molecule clathrating the straight chain molecule and blocking groups arranged at both terminals of the straight chain molecule such that the cyclic molecule does not desorb from the straight chain molecule, covered with silica; a rubber component comprising styrene-butadiene rubber; and at least one of carbon black and silica, wherein the total content of the fine particles, the carbon black and the silica (excluding silica covering rotaxane) is 70 to 150 parts by mass per 100 parts by mass of the rubber component.

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 %.

A method for producing a rubber composition include a mixing step, a drying step, and a dispersion step. In the mixing step, an aqueous solution that includes at least one of oxycellulose fibers and cellulose nanofibers is mixed with rubber latex to obtain a first mixture. In the drying step, the first mixture is dried to obtain a second mixture. In the dispersion step, the second mixture is tight-milled using an open roll to obtain a rubber composition. The rubber composition does not include an aggregate that includes at least one of the oxycellulose fibers and the cellulose nanofibers, and has a diameter of 0.1 mm or more.

A method for producing a rubber composition include a mixing step, a drying step, and a dispersion step. In the mixing step, an aqueous solution that includes at least one of oxycellulose fibers and cellulose nanofibers is mixed with rubber latex to obtain a first mixture. In the drying step, the first mixture is dried to obtain a second mixture. In the dispersion step, the second mixture is tight-milled using an open roll to obtain a rubber composition. The rubber composition does not include an aggregate that includes at least one of the oxycellulose fibers and the cellulose nanofibers, and has a diameter of 0.1 mm or more.

A method for producing a rubber composition include a mixing step, a drying step, and a dispersion step. In the mixing step, an aqueous solution that includes at least one of oxycellulose fibers and cellulose nanofibers is mixed with rubber latex to obtain a first mixture. In the drying step, the first mixture is dried to obtain a second mixture. In the dispersion step, the second mixture is tight-milled using an open roll to obtain a rubber composition. The rubber composition does not include an aggregate that includes at least one of the oxycellulose fibers and the cellulose nanofibers, and has a diameter of 0.1 mm or more.

A rubber composition that is based upon a cross-linkable elastomer composition comprising, per 100 parts by weight of rubber (phr) between 70 phr and 100 phr of an epoxidized rubber component selected from an epoxidized polybutadiene rubber (eBR), an epoxidized styrene-butadiene rubber (eSBR), or combinations thereof, wherein the epoxidized rubber component has a Tg of between −80° C. and −110° C. and an epoxy-function content of between 1 mol % and 25 mol %; between 30 phr and 150 phr of a plasticizing resin; and a quickly reactive silica that provides a macro dispersion Z-value of at least 50 in a defined rubber composition; and a non-silol coupling agent.

A rubber composition that is based upon a cross-linkable elastomer composition comprising, per 100 parts by weight of rubber (phr) between 70 phr and 100 phr of an epoxidized rubber component selected from an epoxidized polybutadiene rubber (eBR), an epoxidized styrene-butadiene rubber (eSBR), or combinations thereof, wherein the epoxidized rubber component has a Tg of between −80° C. and −110° C. and an epoxy-function content of between 1 mol % and 25 mol %; between 30 phr and 150 phr of a plasticizing resin; and a quickly reactive silica that provides a macro dispersion Z-value of at least 50 in a defined rubber composition; and a non-silol coupling agent.

A method of preparing functionalized elastomers, including epoxy ring-opening an epoxidized elastomer with a C.sub.1-C.sub.32 hydrocarbyl-substituted thiol to provide a functionalized elastomer comprising an epoxy functional group, a hydroxy functional group, and a C.sub.1-C.sub.32 hydrocarbyl-substituted thio functional group. The hydroxy functional group and the C.sub.1-C.sub.32 hydrocarbyl-substituted thio functional group are vicinal functional groups.

A method of preparing functionalized elastomers, including epoxy ring-opening an epoxidized elastomer with a C.sub.1-C.sub.32 hydrocarbyl-substituted thiol to provide a functionalized elastomer comprising an epoxy functional group, a hydroxy functional group, and a C.sub.1-C.sub.32 hydrocarbyl-substituted thio functional group. The hydroxy functional group and the C.sub.1-C.sub.32 hydrocarbyl-substituted thio functional group are vicinal functional groups.