1 results about "Nitrogen adsorption" patented technology

The present invention provides a rubber composition for an undertread, the rubber composition achieving excellent low heat build-up and high elastic modulus when formed into a tire; and a pneumatic tire that includes the rubber composition. The rubber composition for an undertread contains a diene rubber and a carbon black. The diene rubber contains a natural rubber and a modified polymer that is obtained by reacting a nitrone compound with a double bond of a conjugated diene polymer. The content of the natural rubber in the diene rubber is 60 mass % or greater, the content of the modified polymer in the diene rubber is from 8 to 40 mass %, the content of the carbon black is from 30 to 67 parts by mass per 100 parts by mass of the diene rubber, and the nitrogen adsorption specific surface area of the carbon black is from 20 to 60 m²/g.