The present invention provides a compounding agent which, when used in a rubber composition containing a reinforcing filler, exhibits excellent dispersibility, workability, toughness, low heat build-up, and wear resistance; and a rubber composition containing the compounding agent. A modified butadiene polymer of the present invention has a functional group containing a nitrogen atom and silicon atom at a terminal, a weight average molecular weight of the modified butadiene polymer being from 1000 to 15000, and a molecular weight distribution of the modified butadiene polymer being 2.0 or less.

The present invention provides a compounding agent which, when used in a rubber composition containing a reinforcing filler, exhibits excellent dispersibility, workability, toughness, low heat build-up, and wear resistance; and a rubber composition containing the compounding agent. A modified butadiene polymer of the present invention has a functional group containing a nitrogen atom and silicon atom at a terminal, a weight average molecular weight of the modified butadiene polymer being from 1000 to 15000, and a molecular weight distribution of the modified butadiene polymer being 2.0 or less.

The present invention relates to a rubber composition having excellent tensile properties and viscoelasticity properties and including a modified conjugated diene-based polymer. The rubber composition may include a modified conjugated diene-based polymer which is selected considering target tensile properties and viscoelasticity properties, by predicting in advance the correlation of the modification ratio of the modified conjugated diene-based polymer and the dynamic viscoelasticity loss coefficient at 60° C. of the rubber composition through Mathematical Formula 1 and Mathematical Formula 2. Therefore, excellent compounding properties may be shown.

Disclosed are a diaphragm for a sound generating device and a sound generating device. The vibration diaphragm comprises at least one elastomer layer, wherein the elastomer layer is made of a hydrogenated nitrile butadiene rubber polymer; and the hydrogenated nitrile butadiene rubber polymer comprises acrylonitrile blocks, content of the acrylonitrile blocks in the hydrogenated nitrile butadiene rubber polymer ranging from 10 wt % to 70 wt %, a vulcanizing agent is added into the hydrogenated nitrile butadiene rubber polymer, and content of the vulcanizing agent is 1% to 15% of total content of the hydrogenated nitrile butadiene rubber polymer. The diaphragm of the present disclosure has excellent resilience, maintains high elasticity in a low-temperature environment and is capable of long-time working in a high-temperature environment, therefore enabling the sound generating device to be applied in an extremely severe environment while keeping its acoustic performance in an excellent state.

The present invention provides a run-flat tire excellent in run-flat durability. In the run-flat tire, a vulcanized rubber of a rubber composition containing a rubber component and a vulcanization accelerator that contains tetrabenzylthiuramdisulfide is used for at least one member selected from the group consisting of a side-reinforcing rubber layer and a bead filler. In the vulcanized rubber of the run-flat tire, a proportion of monosulfide bonds and disulfide bonds in all sulfide bonds is 65% or more.

The present invention provides a run-flat tire excellent in run-flat durability. In the run-flat tire, a vulcanized rubber of a rubber composition containing a rubber component and a vulcanization accelerator that contains tetrabenzylthiuramdisulfide is used for at least one member selected from the group consisting of a side-reinforcing rubber layer and a bead filler. In the vulcanized rubber of the run-flat tire, a proportion of monosulfide bonds and disulfide bonds in all sulfide bonds is 65% or more.

In a production method for a conductive composite material for an extruder that continuously discharges a kneaded product produced by kneading a raw material using a screw, the screw has a the screw body, the raw material transported along an outer circumferential surface of the screw body receives increased pressure by a barrier part in a transport part and is introduced to a passage from an inlet, and while the kneaded product is continuously discharged, the raw material transported along the outer circumferential surface of the screw body flows in the passage of the extruder and then is guided to the transport part via an outlet provided in the screw body, the raw material contains a conductive filler and a thermoplastic elastomer.

In a production method for a conductive composite material for an extruder that continuously discharges a kneaded product produced by kneading a raw material using a screw, the screw has a the screw body, the raw material transported along an outer circumferential surface of the screw body receives increased pressure by a barrier part in a transport part and is introduced to a passage from an inlet, and while the kneaded product is continuously discharged, the raw material transported along the outer circumferential surface of the screw body flows in the passage of the extruder and then is guided to the transport part via an outlet provided in the screw body, the raw material contains a conductive filler and a thermoplastic elastomer.

A roll covering includes a functional layer formed of a polymer which is a blend of at least one rubber and one millable polyurethane rubber. The polymer includes from 65% by weight to 85% by weight of the at least one rubber and from 15% by weight to 35% by weight of the millable polyurethane rubber. A roll having the roll core, a method of using the roll and a combination of the roll and a heated drying cylinder are also provided.

An object of the present invention is to provide a conveyor belt rubber composition having excellent cut resistance and wear 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 50 mass % or more 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 more than 20 mass %, and a proportion of a vinyl structure in repeating units derived from a conjugated diene of 8 mol % or less.