Abstract: A coating rubber composition for a conveyer belt, comprising 15 to 75 parts by mass of carbon black having a nitrogen adsorption specific surface area of 50 m2/g or less, 25 to 100 parts by mass of calcium carbonate and 40 parts or less by mass of an oil per 100 parts by mass of blended rubber comprising of natural rubber and at least one of either butadiene rubber or SBR. The above coating rubber composition for conveyer belts can improve not only the peel force which is a criterion of adhesiveness with the canvas cloth but also the power-saving capability of the conveyer belt while maintaining the durability thereof. Further, compounding of silica in an amount of 5 to 20 parts by mass can achieve a sufficient rubber attachability onto the canvas cloth when over-vulcanized, while maintaining the peel force when subjected to normal vulcanization.

Abstract: The present technology provides a rubber composition containing: a diene-based rubber containing a natural rubber and a butadiene rubber; a carbon black 1; and a carbon black 2. A nitrogen adsorption specific surface area of the carbon black 1 is from 60 to 100 m2/g; a dibutyl phthalate oil absorption of the carbon black 1 is 120 cm3/100 g or less; a nitrogen adsorption specific surface area of the carbon black 2 is from 20 to 40 m2/g; a dibutyl phthalate oil absorption of the carbon black 2 is from 70 to 95 cm3/100 g; and a total amount of the carbon black 1 and the carbon black 2 being from 25 to 50 parts by mass per 100 parts by mass of the diene-based rubber.

Abstract: A rubber-reinforcing steel cord embedded in a rubber product has a stranded structure including a core strand, and a plurality of sheath strands intertwined around an outer circumferential surface of the core strand; wherein a lubricant is provided between wires that constitute the core strand.

Abstract: A conveyor belt includes a core layer disposed between an upper cover rubber layer and a lower cover rubber layer. The core layer is configured from a plurality of steel cords covered by cushioning rubber and arranged in parallel. The rubber that forms the lower cover rubber layer is a low loss rubber that has a loss factor tan? of 0.07 or less at a frequency of 10 Hz, 2% dynamic strain, and temperature of 20° C. The maximum thickness of the cushioning rubber is reduced to not more than ? the nominal diameter of the steel cords.

Abstract: A rubber composition of the present technology for a conveyor belt contains a diene rubber and a carbon black, the diene rubber containing: a natural rubber; and a modified butadiene rubber obtained by modifying a butadiene rubber with a nitrone compound; the content of the natural rubber in the diene rubber being 30 to 85 mass %, and the content of the modified butadiene rubber in the diene rubber being 15 to 70 mass %.

Abstract: The present technology provides a rubber composition containing: a diene-based rubber containing a natural rubber and a butadiene rubber; a carbon black 1; and a carbon black 2. A nitrogen adsorption specific surface area of the carbon black 1 is from 60 to 100 m2/g; a dibutyl phthalate oil absorption of the carbon black 1 is 120 cm3/100 g or less; a nitrogen adsorption specific surface area of the carbon black 2 is from 20 to 40 m2/g; a dibutyl phthalate oil absorption of the carbon black 2 is from 70 to 95 cm3/100 g; and a total amount of the carbon black 1 and the carbon black 2 being from 25 to 50 parts by mass per 100 parts by mass of the diene-based rubber.

Abstract: A rubber-reinforcing steel cord embedded in a rubber product has a stranded structure including a core strand, and a plurality of sheath strands intertwined around an outer circumferential surface of the core strand; wherein a lubricant is provided between wires that constitute the core strand.

Abstract: A rubber composition of the present technology for a conveyor belt contains a diene rubber and a carbon black, the diene rubber containing: a natural rubber; and a modified butadiene rubber obtained by modifying a butadiene rubber with a nitrone compound; the content of the natural rubber in the diene rubber being 30 to 85 mass %, and the content of the modified butadiene rubber in the diene rubber being 15 to 70 mass %.

Abstract: A coating rubber composition for a conveyer belt, comprising 15 to 75 parts by mass of carbon black having a nitrogen adsorption specific surface area of 50 m2/g or less, 25 to 100 parts by mass of calcium carbonate and 40 parts or less by mass of an oil per 100 parts by mass of blended rubber comprising of natural rubber and at least one of either butadiene rubber or SBR. The above coating rubber composition for conveyer belts can improve not only the peel force which is a criterion of adhesiveness with the canvas cloth but also the power-saving capability of the conveyer belt while maintaining the durability thereof. Further, compounding of silica in an amount of 5 to 20 parts by mass can achieve a sufficient rubber attachability onto the canvas cloth when over-vulcanized, while maintaining the peel force when subjected to normal vulcanization.

Abstract: The present technology provides a rubber composition for a conveyor belt. The rubber composition comprises: a rubber component containing butadiene rubber and/or styrene butadiene rubber, carbon black, sulfur, and a vulcanization accelerator; the glass transition temperature of the butadiene rubber and the styrene butadiene rubber being ?65° C. or lower; the nitrogen adsorption specific surface area of the carbon black being 90 m2/g or less; the total content of the butadiene rubber and the styrene butadiene rubber being 50% by mass or greater relative to the content of the rubber component; the content of the carbon black being from 30 to 50 parts by mass per 100 parts by mass of the rubber component; and the mass ratio (sulfur/vulcanization accelerator) of the content of the sulfur to the content of the vulcanization accelerator being 1.5 or less.

Abstract: The present technology provides a rubber composition for a conveyor belt. The rubber composition comprises: a rubber component containing butadiene rubber and/or styrene butadiene rubber, carbon black, sulfur, and a vulcanization accelerator; the glass transition temperature of the butadiene rubber and the styrene butadiene rubber being ?65° C. or lower; the nitrogen adsorption specific surface area of the carbon black being 90 m2/g or less; the total content of the butadiene rubber and the styrene butadiene rubber being 50% by mass or greater relative to the content of the rubber component; the content of the carbon black being from 30 to 50 parts by mass per 100 parts by mass of the rubber component; and the mass ratio (sulfur/vulcanization accelerator) of the content of the sulfur to the content of the vulcanization accelerator being 1.5 or less.

Abstract: A conveyor belt includes a core layer disposed between an upper cover rubber layer and a lower cover rubber layer. The core layer is configured from a plurality of steel cords covered by cushioning rubber and arranged in parallel. The rubber that forms the lower cover rubber layer is a low loss rubber that has a loss factor tan? of 0.07 or less at a frequency of 10 Hz, 2% dynamic strain, and temperature of 20° C. The maximum thickness of the cushioning rubber is reduced to not more than ? the nominal diameter of the steel cords.