RUBBER COMPOSITION FOR A HEAVY DUTY TIRE WITH NATURAL RUBBER BASED TREAD CONTAINING OXIDIZED CARBON BLACK

A rubber composition is disclosed containing, based on parts by weight per 100 parts by weight elastomer (phr), (A) 100 parts by weight conjugated diene-based elastomer(s) comprising: (1) natural cis 1,4-polyisoprene rubber, or (2) natural cis 1,4-polyisoprene rubber and from 5 up to 50 phr of an additional synthetic diene-based rubber comprising at least one of synthetic cis 1,4-polyisoprene rubber, cis 1,4 polybutadiene rubber and styrene/butadiene rubber; and (B) 30 to 100 phr of a rubber reinforcing filler containing oxidized rubber reinforcing carbon black, wherein the reinforcing filler is: (1) carbon black comprising at least one of rubber reinforcing carbon black and said oxidized rubber reinforcing carbon black, provided that said carbon black contains from 25 to 100 weight percent of said oxidized carbon back, or (2) a combination of silica, preferably precipitated silica, and carbon black comprising from 5 to 40 weight percent of said silica, where said carbon black comprises at least one of rubber reinforcing carbon black and oxidized rubber reinforcing carbon black, provided that said carbon black contains from 25 to 100 weight percent of said oxidized rubber reinforcing carbon black. The rubber composition may be used in a tread of a pneumatic tire such as a heavy duty pneumatic tire or truck tire, the tread having a cap/base configuration.