Abstract: The side-reinforcing rubber for run-flat tires of the present invention is a side-reinforcing rubber for run-flat tires, including a vulcanized rubber which is formed of a rubber composition containing a rubber component containing a dienic rubber, a vulcanizing agent, and a carbon black having a dibutyl phthalate oil absorption of 120 mL/100 g or more, and has a specific surface area according to a nitrogen adsorption method of 20 to 80 m2/g, with a ratio of an Sx bond (where x is 3 or more) to all sulfide bonds in the side-reinforcing rubber for run-flat tires being 40% or less. The side-reinforcing rubber for run-flat tires is excellent in durability life.

Abstract: The vulcanized rubber of the present invention is a vulcanized rubber, which is formed from a rubber composition containing a rubber component containing a dienic rubber, and a vulcanizing agent, and has a tensile modulus of elasticity at 25% elongation at 100° C. of 1.2 MPa or more, with a ratio of an Sx bond (where x is 3 or more) to all sulfide bonds being 30% or less. The vulcanized rubber, the tire and the run-flat tire of the invention are excellent in durability life.

Abstract: The side-reinforcing rubber for run-flat tires of the present invention is a side-reinforcing rubber for run-flat tires, including a vulcanized rubber which is formed of a rubber composition containing a rubber component containing a dienic rubber, a vulcanizing agent, and a carbon black having a dibutyl phthalate oil absorption of 120 mL/100 g or more, and has a specific surface area according to a nitrogen adsorption method of 20 to 80 m2/g, with a ratio of an Sx bond (where x is 3 or more) to all sulfide bonds in the side-reinforcing rubber for run-flat tires being 40% or less. The side-reinforcing rubber for run-flat tires is excellent in durability life.

Abstract: This disclosure is to provide a rubber composition excellent in low loss property, breaking resistance and wear resistance. In order to achieve the aforementioned purpose, this disclosure is a rubber composition containing a rubber component having a diene-based polymer and a silica, wherein: the diene-based polymer has 3 or more modified functional groups capable of interacting with the silica merely within a range of ¼ of an entire chain length from a terminal, and has at least one monomer structural unit of a diene-based polymer among the modified functional groups; and a content of the silica is 60 to 250 parts by mass per 100 parts by mass of the rubber component.

Abstract: A method for preparing a functionalized polymer, the method comprising the steps of: (i) polymerizing monomer with an anionic initiator to form a reactive polymer; and (ii) reacting the reactive polymer with a nitrile compound containing a protected amino group, where the protected amino group is directly attached to a moiety selected from the group consisting of acyclic moieties, heterocyclic moieties, and non-aromatic cyclic moieties.

Abstract: Rubber composition containing at least 10 parts by mass, in 100 parts by mass of a rubber component, of a polymer component (B) containing a residue of an organic acid (A) added in a production process of the polymer, and containing from 10 to 150 parts by mass of a reinforcing filler (C), and 6 parts by mass or less in total of the residue of an organic acid (A) and an organic acid (D) used on mixing, per 100 parts by mass of the rubber component, thereby providing a rubber composition and a tire produced by using the composition, by defining the total amount of an acidic component with respect to the total mixed rubber, including an organic acid, such as stearic acid, and an organic acid contained in a residue of an emulsifier added in a production process of emulsion-polymerized SBR.

Abstract: The invention relates to a rubber composition having better workability and fracture resistance than the prior art, and more specifically, to a rubber composition containing a polymer (B) obtained from an emulsion-polymerized polymer latex (A) having a number average molecular weight in the range of 1,000-130,000.

Abstract: A process for preparing a copolymer of an acyclic conjugated diene and a cyclic conjugated diene using a polymerization catalyst system comprising a transition metal compound or a lanthanide metal compound, an alkylating agent, and an inorganic halide alcoholate, and rubber compositions and tires comprising the same. The copolymer contains at least 90% acyclic conjugated diene monomer, has a number average molecular weight of between 40,000 and 300,000, and has a cis-bond content of at least 92%.

Abstract: A method for preparing a functionalized polymer, the method comprising the steps of: (i) polymerizing monomer with an anionic initiator to form a reactive polymer; and (ii) reacting the reactive polymer with a nitrile compound containing a protected amino group, where the protected amino group is directly attached to a moiety selected from the group consisting of acyclic moieties, heterocyclic moieties, and non-aromatic cyclic moieties.

Abstract: This invention relates to a rubber composition including a polyisoprene rubber having a very high cis-1,4-bond content and having an excellent balance between dynamic properties and processability, and more particularly to a rubber composition comprising as a rubber component (A) a synthetic polyisoprene rubber having a cis-1,4-bond content of not less than 99.0%, a 3,4-bond content of not more than 0.5% and a Mooney viscosity ML1+4 (100° C.) of 20-110 and (B) a natural rubber.

Abstract: A process for preparing a copolymer of an acyclic conjugated diene and a cyclic conjugated diene using a polymerization catalyst system comprising a transition metal compound or a lanthanide metal compound, an alkylating agent, and an inorganic halide alcoholate, and rubber compositions and tires comprising the same.

Abstract: A method for preparing a functionalized polymer, the method comprising the steps of preparing a reactive polymer, and reacting the reactive polymer with a halosilane compound containing an amino group.

Abstract: A method for preparing a polydiene polymer, the method comprising: (i) preparing an active polymerization mixture by introducing conjugated diene monomer, and optionally monomer copolymerizable therewith, and a lanthanide-based catalyst system; (ii) adding a nitrile compound containing a protected amino group to the active polymerization mixture; and (iii) adding a co-functionalizing agent to the active polymerization mixture.

Abstract: Compositions and methods for producing polymerization initiators comprising at least two protected primary amine groups. Polymers prepared using such polymerization initiators can comprise a residue of the polymerization initiator and can initially comprise the at least two protected primary amine groups. Such polymers can undergo a deprotection process thereby yielding a polymer having one or more unprotected primary amine groups. Polymers having primary amine groups can be employed in rubber compositions, which have a variety of potential applications, such as, for example, in tire manufacturing.

Abstract: A process for preparing a copolymer of an acyclic conjugated diene and a cyclic conjugated diene using a polymerization catalyst system comprising a transition metal compound or a lanthanide metal compound, an alkylating agent, and an inorganic halide alcoholate, and rubber compositions and tires comprising the same. The copolymer contains at least 90% acyclic conjugated diene monomer, has a number average molecular weight of between 40,000 and 300,000, and has a cis-bond content of at least 92%.

Abstract: The invention relates to a rubber composition having better workability and fracture resistance than the prior art, and more specifically, to a rubber composition containing a polymer (B) obtained from an emulsion-polymerized polymer latex (A) having a number average molecular weight in the range of 1,000-130,000.

Abstract: Rubber composition containing at least 10 parts by mass, in 100 parts by mass of a rubber component, of a polymer component (B) containing a residue of an organic acid (A) added in a production process of the polymer, and containing from 10 to 150 parts by mass of a reinforcing filler (C), and 6 parts by mass or less in total of the residue of an organic acid (A) and an organic acid (D) used on mixing, per 100 parts by mass of the rubber component, thereby providing a rubber composition and a tire produced by using the composition, by defining the total amount of an acidic component with respect to the total mixed rubber, including an organic acid, such as stearic acid, and an organic acid contained in a residue of an emulsifier added in a production process of emulsion-polymerized SBR.

Abstract: A method for preparing a functionalized polymer, the method comprising the steps of (i) polymerizing conjugated diene monomer by employing a lanthanide-based catalyst to form a reactive polymer, and (ii) reacting the reactive polymer with a protected oxime compound.

Abstract: A method for preparing a functionalized polymer, the method comprising the steps of (i) polymerizing monomer with a coordination catalyst to form a reactive polymer; and (ii) reacting the reactive polymer with a nitrile compound containing a protected amino group.

Abstract: Compositions and methods for producing polymerization initiators comprising at least two protected primary amine groups. Polymers prepared using such polymerization initiators can comprise a residue of the polymerization initiator and can initially comprise the at least two protected primary amine groups. Such polymers can undergo a deprotection process thereby yielding a polymer having one or more unprotected primary amine groups. Polymers having primary amine groups can be employed in rubber compositions, which have a variety of potential applications, such as, for example, in tire manufacturing.