The present invention provides a pneumatic tire having excellent durability. Provided is a pneumatic tire including at least one steel belt layer, at least one cap ply layer, and at least one carcass layer, the steel belt layer including a steel belt topping rubber composition which has a zinc oxide content of 8.0 parts by mass or more per 100 parts by mass of the rubber component, the cap ply layer including a cap ply topping rubber composition, the carcass layer including a carcass topping rubber composition, the cap ply topping rubber composition and the carcass topping rubber composition both having stearic acid and zinc oxide contents, each per 100 parts by mass of the rubber component, which satisfy the following relationships (1) and (2):

stearic acid content3.0 parts by mass,(1):

stearic acid content/zinc oxide content0.5.(2):

The present invention relates to a pneumatic tire having a tread comprising a tread base layer and a tread cap. The tread cap comprises a first tread cap layer and a second tread cap layer of different polymeric compositions, the tread cap having a central cap zone Z.sub.C and two lateral cap zones Z.sub.L the lateral cap zones Z.sub.L being located axially adjacent to the central cap zone Z.sub.C and on axially opposite sides of the central cap zone Z.sub.C.

A rubber composition suited to forming a tire ply includes 100 phr of elastomer, at least 30 phr of an intermediate carbon black, at least 5 phr silica, such as high surface area silica particles, at least 0.1 phr of a tear strength agent, a sulfur-based curing agent, and an accelerator for the curing agent. The elastomer incudes 60-100 phr of a conjugated diene elastomer. The intermediate carbon black has a statistical thickness surface area (STSA) of from 50 m.sup.2/g to 70 m.sup.2/g.

The present invention provides a cap tread rubber composition and a pneumatic tire formed from the rubber composition which are excellent in grip performance and abrasion resistance during high speed running. Provided is a cap tread rubber composition, containing: styrene butadiene rubber and/or polybutadiene rubber; an isoprene-based rubber; a filler; and a plasticizer, the rubber composition containing, based on 100% by mass of a rubber component therein, at least 90% by mass in total of the styrene butadiene rubber and/or polybutadiene rubber and 0.3% to 10% by mass of the isoprene-based rubber, the filler including, based on 100% by mass thereof, at least 80% by mass of silica, the rubber composition containing, per 100 parts by mass of the rubber component, at least 110 parts by mass of the silica and at least 50 parts by mass of the plasticizer.

The invention relates to a tire having a rubber tread of a circumferentially zoned tread. The tread zones are comprised of three circumferential load bearing zones, with each zone containing a portion of the running surface of the tread, comprised of an intermedial rubber zone positioned between and extending beneath two stratified lateral tread rubber zones. The tread configuration contains an underlying carbon black-rich base rubber layer. The lateral tread rubber zones are therefore spaced apart from each other with the intermedial tread zone therebetween and also spaced apart from the tread base rubber layer with the intermedial tread zone therebetween. The intermedial and stratified lateral zones are comprised of rubber compositions having differentiated rebound physical properties.

Provided is a pneumatic tire including a sidewall that has a good balance of excellent handling stability, rolling resistance, and durability and further has excellent flex crack growth resistance. The sidewall is formed from a modified cellulose fiber-containing rubber composition that is allowed to simultaneously achieve excellent rigidity, excellent tensile properties, and low energy loss by improving the dispersibility of the cellulose fiber in rubber. The present invention relates to a pneumatic tire including a sidewall formed from a modified cellulose fiber-containing rubber composition, the modified cellulose fiber-containing rubber composition containing a modified cellulose fiber (A) obtained by adding a C15 or higher cyclic polybasic acid anhydride (a) containing a hydrophobic group to a cellulose fiber through esterification, a dispersing polymer (B) having a softening point of 135 C. or lower, and a rubber component (C).

Metallated aminosilane compounds for use as functional initiators in anionic polymerizations and processes for producing an aminosilane-functionalized polymer using the metallated aminosilane compounds to initiate anionic polymerization of at least one type of anionically polymerizable monomer. Preferred use of the metallated aminosilane compounds results in rubber compositions for use in tires comprising an aminosilane functionalized polymer.

The invention aims to provide a pneumatic tire achieving a balanced improvement in dry grip performance and abrasion resistance. The invention relates to a pneumatic tire including a component that contacts a road during running, the component being formed from a rubber composition for a component that contacts a road during running which contains: SBR; a short cellulose fiber having an average fiber length of 10 m to 10 mm; and a silica having a N.sub.2SA of 100 m.sup.2/g or more and/or a carbon black having a N.sub.2SA of 70 m.sup.2/g or more, the SBR being present in an amount of 60% by mass or more per 100% by mass of the rubber component, the rubber composition containing, per 100 parts by mass of the rubber component, 0.1-20 parts by mass of the fiber and at least 60 parts by mass in total of the silica and/or the carbon black.

Provided are a rubber composition for studless winter tires that can improve not only performance on snow and ice but also abrasion resistance, thereby simultaneously achieving excellent performance on snow and ice and excellent abrasion resistance, and a studless winter tire formed from the rubber composition. The rubber composition for studless winter tires contains: a rubber component; a chemically modified microfibrillated cellulose; carbon black; and silica, the chemically modified microfibrillated cellulose having an average fiber diameter of 0.1 m or less, the rubber component having a combined amount of natural rubber and polybutadiene rubber of 30-100% by mass based on 100% by mass of the rubber component, the rubber composition containing, per 100 parts by mass of the rubber component, 1-10 parts by mass of the chemically modified microfibrillated cellulose, 10-80 parts by mass of the carbon black, and 10-80 parts by mass of the silica.

Provided are a cap tread rubber composition for cold weather tires enabling a balanced improvement in fuel economy, abrasion resistance, performance on ice/snow, and high-speed performance on snow-/ice-free cold roads, and a cold weather tire formed from the same. The rubber composition contains: a rubber component including BR, SBR, and NR and/or IR; and a filler, the composition having a combined amount of NR, IR, and BR of 80% by mass or more, an amount of BR of 30% by mass or more, and an amount of SBR of 0.3-10% by mass, each per 100% by mass of the rubber component, the filler including 60% by mass or more of silica per 100% by mass of the filler, the composition containing, per 100 parts by mass of the rubber component, 50 parts by mass or more of a fine particle silica having a N.sub.2SA of 190 m.sup.2/g or more.