Tread rubber composition and pneumatic tire

Abstract

Provided are a tread rubber composition that can achieve a balanced improvement in fuel economy, wet-grip performance, and abrasion resistance, and a pneumatic tire including the composition. The tread rubber composition includes: a rubber component; silica; and a silane-coupling agent containing a mercapto group, the rubber component including per 100% by mass thereof 5% by mass or more of a conjugated diene polymer (A), the polymer (A) including a monomer unit derived from a conjugated diene, a monomer unit derived from a compound of formula (1), and a monomer unit derived from a compound of formula (2), at least one end of the copolymer (A) being modified by the following compound (G) or an alkoxysilane compound, the composition including 5-150 parts by mass of the silica per 100 parts by mass of the rubber component, Compound (G): at least one compound selected from the group consisting of compounds containing an optionally-substituted amino group and a carbonyl group and compounds containing an optionally-substituted amino group and a thiocarbonyl group,V-S  (1)V-A  (2)wherein Vand Veach represent a hydrocarbyl group containing a polymerizable carbon-carbon double bond; Srepresents a substituted silyl group, and Arepresents a substituted amino group or a nitrogen-containing heterocyclic group.