Provided is a pneumatic tire wherein a rubber composition is used in a tread rubber, a sidewall rubber, or a rim strip. The rubber composition contains a diene rubber, a petroleum-derived wax, a fatty acid metal salt and a compound represented by the formula (1) (in the formula, R.sup.1 and R.sup.2 each represent a hydrogen atom, an alkyl group, an alkenyl group or an alkynyl group, and M.sup.+ represents N.sup.+, K.sup.+, or Li.sup.+), wherein the amount of a phenylenediamine age resister is less than 1 phr, and a difference obtained by subtracting the number of carbon atoms in a constituent fatty acid contained the most in the fatty acid metal salt from the number of carbon atoms in a hydrocarbon contained the most in the petroleum-derived wax is −10 to 8. Thereby, the pneumatic tire can suppress whitening and discoloration to reddish brown while maintaining ozone resistance and improve appearance.

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A modified conjugated diene-based polymer, and more particularly, a modified conjugated diene-based polymer prepared by continuous polymerization and having remarkable processability, narrow molecular weight distribution and excellent physical properties, and a rubber composition including the same.

Provided are a rubber composition for tires that provides improved silica dispersion and fuel economy while maintaining good hardness, and a pneumatic tire including the rubber composition. The present invention relates to a rubber composition for tires, containing a rubber component, silica, and a silica dispersing agent represented by the following formula (I).

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To provide a tire rubber composition that is capable of producing a tire that is excellent in balance between the low heat generation property and the crack resistance. The tire rubber composition contains a rubber component (A), at least one compound (B) selected from the group consisting of a compound represented by the formula (I) and a compound represented by the formula (II), a vulcanization accelerator (C) containing two or more kinds of vulcanization accelerators including a thiuram-based vulcanization accelerator, and a filler (D).

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Problem to be Solved

The present invention provides a conjugated diene-based polymer composition excellent in rolling resistance, grip performance on a wet road surface, and abrasion resistance when formed into a tire.

Solution

A conjugated diene-based polymer composition containing: 10 to 90 parts by mass of a conjugated diene-based polymer (A) having a glass transition temperature of −20° C. or more; and 10 to 90 parts by mass of a conjugated diene-based polymer (B) having a glass transition temperature of −25° C. or less, wherein the conjugated diene-based polymer (A) has an absolute molecular weight, measured by viscosity detector-equipped GPC-light scattering measurement, of 40×10.sup.4 or more and 5000×10.sup.4 or less, and a branch number (Bn), measured by the viscosity detector-equipped GPC-light scattering measurement, of 8 or more.

The present application provides a rubber composition as a raw material of a rubber for coating steel cords, which shows an effect of a durability improvement. The present application also provides a pneumatic tire including the rubber for coating steel cords superior in the durability. The objectives above can be solved by providing a rubber composition, including: a rubber component a filler, a vulcanization agent, a vulcanization accelerator, a resorcinol resin, and a heat-resistant crosslinking agent, wherein the rubber composition includes a cobalt salt at a content of 0.1 part by mass or less with respect to 100 parts by mass of the rubber component, as well as by providing a pneumatic tire including a rubber for coating steel cords which has been obtained by vulcanizing the rubber composition.

The present invention provides a rubber composition having reduced its odor, which can show a durability improvement effect, as well as to provide a pneumatic tire including the rubber for coating steel cords which is superior in its durability. The objectives above can be solved by providing a rubber composition, including a rubber component a filler, a vulcanization agent, a vulcanization accelerator, and a resorcinol resin, in which the resorcinol resin includes a cresol residue at a content of 0.2 mass % or less, as well as providing a pneumatic tire which has been obtained by vulcanizing the rubber composition, and in particular providing a pneumatic tire in which the rubber is a rubber for coating steel cords.

The invention relates to a sulfur-crosslinkable rubber mixture, in particular for rubber-coating reinforcements in elastomer products, especially in vehicle tires, or inner components of vehicle tires, as well as to a vehicle tire. The rubber mixture comprises a diene rubber, an adhesive system, 10 to 200 phr silica, and 2 to 20 phr of a silane of the formula [(R.sup.1).sub.3Si—X].sub.mS.sub.n(R.sup.2).sub.2-m, where residues R.sup.1 are identical or different alkoxy groups, cyclic dialkoxy groups, cycloalkoxy groups, phenoxy groups, aryl groups, alkyl groups, alkenyl groups, aralkyl groups, or halides, and where X is a polar organic group containing urea, m represents the value 1 or 2, n is an integer between 1 and 8, and R.sup.2 is a hydrogen atom or an acyl group comprising 1 to 20 carbon atoms.

A resin-rubber composite includes: a resin member that has a treated surface, to which a surface treatment by means of a plasma treatment has been applied; and a rubber member that is disposed in contact with the treated surface of the resin member and includes a rubber, a filler having a silanol group, and a silane coupling agent, with a filler content of from 30 phr to 100 phr with respect to 100 phr of the rubber, and a silane coupling agent content of from 2 parts by mass to 15 parts by mass with respect to 100 parts by mass of the filler.

Provided is a rubber material that is well-balanced in terms of tensile strength, low hysteresis loss property, wet grip property, and abrasion resistance. A hydrogenated conjugated diene-based polymer which is a hydrogenation product of a conjugated diene-based polymer including butadiene-derived structural units is produced by a method comprising a step of preparing a conjugated diene-based polymer having, at a side chain moiety thereof, a functional group capable of interacting with silica; and a step of hydrogenating the conjugated diene-based polymer so as to achieve a hydrogenation rate of 80 to 99% of butadiene-derived structural units included in the conjugated diene-based polymer.