A rubber composition includes: in a diene rubber containing a natural rubber, cobalt borate neodecanoate, a phenol-based resin, and a curing agent; a dynamic storage modulus (E) at 20 C. and a dynamic strain of 2% being 13 MPa or greater; a loss tangent (tan ) at 60 C. being 0.20 or less; and the number of repetitions until breakage in a constant strain fatigue test at a strain of 60% and 400 rpm being 35000 times or greater.

The invention relates to a tire with radial carcass reinforcement, made up of at least one layer of metal reinforcing elements, the said tire comprising a crown reinforcement, itself radially capped by a tread, the said tread being connected to two beads via two side walls, the said tire comprising a first layer of polymer compound radially between the carcass reinforcement and the radially innermost layer of reinforcing elements of the crown reinforcement. According to the invention, the said first layer of polymer compound constitutes a buffer zone designed to trap oxygen on the outside of the said first layer, the axial width of the said first layer being at least equal to 70% of the width of the radially innermost layer of reinforcing elements of the crown reinforcement.

Tire comprising a crown reinforcement formed of at least two working crown layers of reinforcing elements, crossed from one layer to the other making with the circumferential direction angles comprised between 10 and 45. A first layer S of polymer compound is in contact with at least one working crown layer and in contact with the carcass reinforcement, the said first layer S of polymer compound extending axially as far as at least the axial end of the tread and the complex dynamic shear modulus G*, measured at 10% and 60 C. on the return cycle, of the first layer S of polymer compound is greater than 1.35 MPa.

Tire comprising a crown reinforcement formed of at least two working crown layers of reinforcing elements, crossed from one layer to the other making with the circumferential direction angles comprised between 10 and 45. A first layer S of polymer compound is in contact with at least one working crown layer and in contact with the carcass reinforcement, the first layer S of polymer compound extending axially as far as at least the axial end of the tread, the first layer S of compound polymer compound is made up of a filled elastomer blend having a macro dispersion coefficient Z greater than or equal to 65 and a maximum tan() value, denoted tan()max, less than 0.100 and its complex dynamic shear modulus G*, measured at 10% and 60 C. on the return cycle is greater than 1.35 MPa.

A rubber composition comprising a zinc oxide which comprises aluminum and iron. The zinc oxide's content of the iron is preferably 15 ppm or more and 100 ppm or less and the zinc oxide's content of the aluminum is 40 ppm or more and 100 ppm or less. The zinc oxide's ratio of a content of the iron to a content of the aluminum is preferably 0.2 to 2.3. The zinc oxide's content of the iron is preferably 15 ppm or more and 80 ppm or less. The rubber composition is used for rubber-steel cord composites.

In a first aspect of the present invention, a rubber composition is provided, comprising at least one rubber, at least one filler, at least one thermoplastic polymer, wherein the thermoplastic polymer is a poly alkylacrylate, and wherein the alkylacrylate comprises a polycyclic substituent at its single bonded oxygen atom. In another aspect of the invention, an article of manufacture such as a tire, a power transmission belt, a hose, a track, an air sleeve, and a conveyor belt is provided which comprises the rubber composition in accordance with the first aspect.

Disclosed herein are methods for improving the rolling resistance of a tire rubber composition by providing a rubber composition including a rubber component which includes a majority by weight of guayule rubber where the guayule rubber includes a bagasse component, and a filler component where the filler component is free of silica, and including at least one silane in the rubber composition, where the at least one silane is selected from the group consisting of mercaptosilanes, blocked mercaptosilanes, and alkoxysilanes. Also disclosed is a tire rubber composition which comprises (a) 100 parts of a rubber component including a majority by weight of guayule rubber where the guayule rubber includes a bagasse component, (b) a filler component, where the filler component is free of silica, and (c) at least one silane selected from the group consisting of mercaptosilanes, blocked mercaptosilanes, and alkoxysilanes.

A pneumatic tire having a tread portion and a belt layer, wherein the reinforcing cords in the belt layer are composed of monofilament cords arranged in the tire width direction at least 50 cords/5 cm in the cross section of the belt layer in the tire radial direction. A pneumatic tire that is installed on a standardized rim and satisfies the following (formula 1), where Wt (mm) is the cross-sectional width of the tire and Dt (mm) is the outer diameter of the tire when the internal pressure is 250 kPa:

1500(Dt.sup.2/4)/Wt(formula 1).

A pneumatic tire having a tread section and a belt layer, wherein monofilament cords are used as reinforcing cords in the belt layer, and an arranged number e of the monofilament cords per 5 cm in the tire-width direction (cords/5 cm) in a tire radial direction cross-section of the belt layer, and a tire cross-sectional width Wt (mm), incorporated in a standardized rim and with an internal pressure of 250 kPa, satisfies (formula 1) and (formula 2) below:

e/(0.31Wt+14.35)>1(formula 1);

e/(0.31Wt+56.45)(formula 2).

The environmental footprint of a tire for a construction plant vehicle is improved. To do so, the elastomer compounds derived from non-fossil resources represent a mass content greater than or equal to 65% of the total mass of the compounds of the tire, at least 75% of the total mass of the compounds of the tire is made up of elastomer compounds each of which has a viscoelastic loss, measured in terms of tan(), less than or equal to 0.065, and an electrical resistivity greater than or equal to 1E+10 .Math.cm.