A compound represented by the formula:

##STR00001## wherein each R is independently selected from the group consisting of (i) substituted or unsubstituted alkyl with C=0 to 12 inclusive; wherein X.sup.1, X.sup.2, X.sup.3 and X.sup.4 are each independently selected from the group consisting of alkyl, aryl, alkylaryl groups and hydrogen; wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are each independently selected from the group consisting of alkyl, aryl, alkylaryl groups and hydrogen; and wherein one of R.sup.1 and R.sup.2 and one of R.sup.3 and R.sup.4 may optionally be bridged by a polymethylene group to form a cycloalkyl; wherein when C=0 in R, the combined group R.sup.1 R.sup.2 is the same as the combined group R.sup.3 R.sup.4; and wherein when C=1 in R, each of R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are hydrogen.

To improve durability performance and rolling resistance performance in a well-balanced manner. It is a tire for heavy loads including a carcass ply (6A). A sidewall rubber (3G) includes an inside rubber part (15) on the carcass (6) side, and an outside rubber part (16) disposed on the outside thereof and forming a tire outer surface. The inside rubber part (15) has a loss tangent tan δ1 less than the outside rubber part (16), and their difference is 0.010 to 0.035. The inside rubber part (15) has a complex elastic modulus less than the outside rubber part (16), their difference is 0.5 to 1.4 (MPa). The outer end (15s) in the tire radial direction of the inside rubber part (15) contacts with the outer surface (2h) in the tire axial direction of the tread rubber (2G), and the inner end (15u) in the tire radial direction is disposed radially inside the outer end (6e) in the tire radial direction of the turned up portion (6b) of the carcass ply (6A).

The present invention aims to provide a rubber composition for tires that can improve processability, crack resistance, ozone resistance, discoloration resistance, and tire appearance while maintaining a good balance between them, and also to provide a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition for tires, containing: a rubber component; an antioxidant; and polyether, the rubber component having a combined content of polybutadiene rubber, natural rubber, and polyisoprene rubber of 80% by mass or more per 100% by mass of the rubber component, the rubber composition containing the antioxidant in an amount of 0.3 to 7.0 parts by mass per 100 parts by mass of the rubber component, the polyether having an average mass content of at least two consecutive polyethylene oxide units of 85% or less of the polyethylene oxide mass content of the polyether.

The present invention is directed to a pneumatic tire comprising a sidewall component, the sidewall component including an air passageway extending at least partially about the circumference of the tire, the air passageway surrounded by and in fluid communication with a surface comprising a rubber composition, the rubber composition comprising: a diene based rubber; from 0.25 to 5 parts by weight, per 100 parts by weight of rubber (phr), of a self-lubrication agent capable of migrating from the rubber composition to the groove surface and disposing on the groove surface as a liquid; and from 1 to 15 parts by weight, per 100 parts by weight of rubber (phr), of a vulcanization modifier for use in the second rubber composition include α,ω-bis(N,N′-dihydrocarbylthiocarbamamoyldithio)alkanes, bismaleimides, and biscitraconimides.

A self-inflating tire assembly includes an air tube mounted within a tire sidewall groove. The air tube is in contacting engagement with opposite angled groove surfaces surrounding the air tube. A segment of the air tube is flattened from an expanded diameter to a flat diameter by bending and compression of the groove in a rolling tire footprint to force air evacuated from the flattened segment along a tube air passageway. The sidewall groove extends into an annular, axially extending, sidewall surface such as an axially oriented surface of a tire chafer protrusion located in non-contacting relationship with the rim. The opposite groove surfaces comprise a rubber composition, the rubber composition comprising: a diene based rubber; from 0.25 to 5 parts by weight, per 100 parts by weight of rubber (phr), of a self-lubrication agent capable of migrating from the rubber composition to the groove surface and disposing on the groove surface as a liquid; and from 1 to 15 parts by weight, per 100 parts by weight of rubber (phr), of a vulcanization modifier for use in the second rubber composition include α,ω-bis(N,N′-dihydrocarbylthiocarbamamoyldithio)alkanes, bismaleimides, and biscitraconimides.

Rubber composition which improves dispersibility of silica and enhances processability by reducing viscosity of an unvulcanized rubber and which suppresses rubber scorching, inhibits shrinkage without delaying a vulcanization rate and improves a heat resistance, and a tire prepared by using the above rubber composition. Rubber composition prepared by blending at least one rubber component selected from a natural rubber and/or a diene base synthetic rubber with silica and a glycerin fatty acid ester composition, wherein a blend amount of the glycerin fatty acid ester composition is 0.5 to 15 parts by mass based on 100 parts by mass of the rubber component; the fatty acid has 8 to 28 carbon atoms; the glycerin fatty acid ester composition contains glycerin fatty acid monoester and glycerin fatty acid diester; and a content of the glycerin fatty acid monoester in the glycerin fatty acid ester composition is 85% by mass or less.

Provided are a rubber composition having a good balance of improved fuel efficiency, abrasion resistance, and wet grip performance while providing good processability, and a pneumatic tire having a tread manufactured from the rubber composition. A rubber composition comprising: a copolymer synthesized by copolymerization of a conjugated diene monomer and an unsaturated acyclic monoester represented by the formula (1) below; and carbon black and/or silica, ##STR00001##
wherein R.sup.1 represents hydrogen or a C1-C30 hydrocarbon group, and R.sup.2 represents hydrogen or a C1-C30 hydrocarbon group.

A pneumatic tire having a sidewall cover layer for application of a printing ink and/or paint is provided. In one embodiment, the tire comprises: a sidewall portion including a cushion layer and a cover layer, wherein the cover layer is oriented axially outwardly of the cushion layer, wherein the cover layer is bonded to the cushion layer, wherein the cover layer is formed from a material that contains wax in a concentration of less than 0.03 pph, and wherein the cushion layer does not contain a wax.

Provided are: a rubber composition for tires that achieves a balanced improvement in handling stability, crack resistance, ozone resistance, discoloration resistance, tire appearance, fuel economy, tensile strength, and scorch resistance; and a pneumatic tire formed from the rubber composition. The invention relates to a rubber composition for tires containing: a rubber component having a combined content of polybutadiene rubber, natural rubber, and polyisoprene rubber of 90% by mass or more based on 100% by mass of the rubber component; sulfur; and at least one nonionic surfactant selected from the group consisting of a Pluronic nonionic surfactant, and a nonionic surfactant represented by the formula (1) below and/or a nonionic surfactant represented by the formula (2) below, the rubber composition containing, per 100 parts by mass of the rubber component, 2-70 parts by mass of carbon black and 1-5 parts by mass of silica, and being free of silane coupling agents,

##STR00001##

wherein R.sup.1 represents a C6-C26 hydrocarbon group having an unsaturated bond, and d represents an integer,

##STR00002##

wherein R.sup.2 and R.sup.3 are the same or different and each represent a C6-C26 hydrocarbon group, and e represents an integer.

A tire is provided with an external sidewall, the said external sidewall comprising at least one composition based on at least from 15 to 70 phr of isoprene elastomer, from 25 to 85 phr of butadiene elastomer, from 10 to 100 phr of carbon black, from 0.75 to 2.7 phr of polyethylene oxide derivative of general formula (Chem 1) below, in which n is a number within a range extending from 20 to 25, and m is a number within a range extending from 13 to 17, from 0.5 to 10 phr of antiozone wax, and a crosslinking system

##STR00001##