Pneumatic tire for heavy load

Abstract

A pneumatic tire for heavy loads having a rubber composition for a tread rubber for a construction vehicle or the like, containing carbon black having a nitrogen adsorption specific surface area of 100 to 160 m.sup.2 /g, and an oil (dibutyl phthalate) absorption amount (DBP) of 80 to 130 ml/100 g, and silica having a nitrogen adsorption specific surface area of 210 to 260 m.sup.2 /g, and an oil absorption amount of 200 to 260 ml/100 g, by a total content of 40 to 70 parts by weight, in 100 parts by weight of isoprene rubber material, wherein the rubber composition contains 3 to 15 parts by weight of the total content. Further, the rubber composition contains 30 to 50 parts by weight of carbon black having a nitrogen adsorption specific surface area of 130 to 180 m.sup.2 /g, and an oil (dibutyl phthalate) absorption amount (DBP) of 80 to 120 ml/100 g, and 5 to 15 parts by weight of silica having a nitrogen adsorption specific surface area of 170 m.sup.2 /g or more, and 2.0 parts by weight or more of aging preventive agent, in 100 parts by weight of isoprene rubber material, wherein the compounding ratio of silica to carbon black (silica/carbon black) in the rubber composition is in a range of from 0.1 to 0.5 in the rubber composition.

Dependencies are inferred from the claim text.