The present disclosure provides a rubber composition and a tire which provide improved overall performance in terms of wet performance and dry performance. The present disclosure relates to a rubber composition, containing at least one polybutadiene rubber and/or at least one styrene-butadiene rubber, having a complex modulus E* that reversibly changes with water, and satisfying the following relationships 1) to 3): 1) Complex modulus E* when water-wet/Complex modulus E* before water-wet×100≤98 wherein E* represents the E* at 23° C. of the rubber composition; 2) 99≤Complex modulus E* after water-wet and dehydrated/Complex modulus E* before water-wet×100≤100 wherein E* represents the E* at 23° C. of the rubber composition; 3) 99≤Volume when water-wet/Volume before water-wet×100≤100 wherein Volume represents the volume at 23° C. of the rubber composition.

The present disclosure provides a rubber composition and a tire which provide improved overall performance in terms of wet performance and dry performance. The present disclosure relates to a rubber composition, containing at least one polybutadiene rubber and/or at least one styrene-butadiene rubber, having a complex modulus E* that reversibly changes with water, and satisfying the following relationships 1) to 3): 1) Complex modulus E* when water-wet/Complex modulus E* before water-wet×100≤98 wherein E* represents the E* at 23° C. of the rubber composition; 2) 99≤Complex modulus E* after water-wet and dehydrated/Complex modulus E* before water-wet×100≤100 wherein E* represents the E* at 23° C. of the rubber composition; 3) 99≤Volume when water-wet/Volume before water-wet×100≤100 wherein Volume represents the volume at 23° C. of the rubber composition.

Compositions comprising phosphonate-functionalized polyene copolymers and a reinforcing filler, in particular rubber compositions, and to their uses is provided.

This phosphonate-functionalized polyene copolymer comprises, in its main linear chain, unsaturated units resulting from at least one conjugated polyene monomer and units substituted by a —C(O)O-A-P(O)OR.sub.1OR.sub.2 functional group, in which R.sub.1 and R.sub.2, which are identical or different, each represent H or a C.sub.1-C.sub.6 alkyl and A represents a (C.sub.1-C.sub.6)alkylene radical or a (C.sub.1-C.sub.5)alkylene radical containing at least one heteroatom.

The use of this copolymer in a tire composition additionally comprising a diene elastomer and a reinforcing filler, for improving the interactions between the filler and the diene elastomer included in the said tire composition is also provided.

Compositions comprising phosphonate-functionalized polyene copolymers and a reinforcing filler, in particular rubber compositions, and to their uses is provided.

This phosphonate-functionalized polyene copolymer comprises, in its main linear chain, unsaturated units resulting from at least one conjugated polyene monomer and units substituted by a —C(O)O-A-P(O)OR.sub.1OR.sub.2 functional group, in which R.sub.1 and R.sub.2, which are identical or different, each represent H or a C.sub.1-C.sub.6 alkyl and A represents a (C.sub.1-C.sub.6)alkylene radical or a (C.sub.1-C.sub.5)alkylene radical containing at least one heteroatom.

The use of this copolymer in a tire composition additionally comprising a diene elastomer and a reinforcing filler, for improving the interactions between the filler and the diene elastomer included in the said tire composition is also provided.

A rubber composition for tires of the present technology contains a diene rubber, silica, and a predetermined alkyltrialkoxysilane; the diene rubber containing a butadiene rubber and a particular conjugated diene rubber, a content of the butadiene rubber in the diene rubber being 20 mass % or greater and a content of the particular conjugated diene rubber in the diene rubber being from 30 to 80 mass %; an average glass transition temperature of the diene rubber being from −65 to −45° C.; the particular conjugated diene rubber being a conjugated diene rubber produced by a particular production method and having predetermined ranges of aromatic vinyl unit content, vinyl bond content, and weight average molecular weight.

A rubber composition for tires of the present technology contains a diene rubber, silica, and a predetermined alkyltrialkoxysilane; the diene rubber containing a butadiene rubber and a particular conjugated diene rubber, a content of the butadiene rubber in the diene rubber being 20 mass % or greater and a content of the particular conjugated diene rubber in the diene rubber being from 30 to 80 mass %; an average glass transition temperature of the diene rubber being from −65 to −45° C.; the particular conjugated diene rubber being a conjugated diene rubber produced by a particular production method and having predetermined ranges of aromatic vinyl unit content, vinyl bond content, and weight average molecular weight.

A rubber composition for tires of the present technology contains a diene rubber, silica, a silane coupling agent, a fatty acid metal salt, and a predetermined alkyltrialkoxysilane; the diene rubber containing 60 mass % or greater of a modified conjugated diene rubber and 30 mass % or greater of a particular conjugated diene rubber which corresponds to a part or all of the modified conjugated diene rubber; an average glass transition temperature of the diene rubber being from −45 to −20° C.; the particular conjugated diene rubber being a conjugated diene rubber produced by a particular production method and having predetermined ranges of aromatic vinyl unit content, vinyl bond content, and weight average molecular weight.

A rubber composition for tires of the present technology contains a diene rubber, silica, a silane coupling agent, a fatty acid metal salt, and a predetermined alkyltrialkoxysilane; the diene rubber containing 60 mass % or greater of a modified conjugated diene rubber and 30 mass % or greater of a particular conjugated diene rubber which corresponds to a part or all of the modified conjugated diene rubber; an average glass transition temperature of the diene rubber being from −45 to −20° C.; the particular conjugated diene rubber being a conjugated diene rubber produced by a particular production method and having predetermined ranges of aromatic vinyl unit content, vinyl bond content, and weight average molecular weight.

A method for preparing a coupled polymer, the method comprising the steps of polymerizing monomer to form a reactive polymer and reacting the reactive polymer with a carboxylic or thiocarboxylic ester containing a nitro group, where the carboxylic or thiocarboxylic ester containing a nitro group includes a single nitro group.

Disclosed herein are a process for preparing a modified high-cis polybutadiene polymer, a modified high-cis polybutadiene polymer, and tire components made using the modified high-cis polybutadiene polymer. The processes make use of a functionalizing compound of formula (I) to prepare the modified high-cis polybutadiene from a quantity of 1,3-butadiene monomer using a specified catalyst system.