Chemical compositions of a tire cord steel with high strength and low wire breakage rate may include Nb, V and N, and ([Nb]+[V])/[N] is 3-4.5, [Nb] representing the mass fraction of niobium element, [V] representing the mass fraction of vanadium element, and [N] representing the mass fraction of nitrogen element. The method includes: obtaining a steel billet of the tire cord steel; and sequentially performing a heating-before-rolling, a hot-rolling and a cooling-after-rolling on the steel billet to obtain a wire rod of the tire cord steel. The application of the tire cord steel is to apply the tire cord steel in tire skeleton materials. The strength and toughness of the tire cord steel can be improved by adding Nb, V and N, and then controlling the relationship between Nb, V and N.

A tire having a radial carcass reinforcement, made up of a single layer of reinforcing elements anchored in each of the beads by being turned up around a bead wire, reinforced by a stiffener. The two working crown layers are the only ones present to form the crown reinforcement over at least 75% of the width of the tread, the absolute value of the difference between the absolute values of the angles 2 and 1 being greater than 7, 2 being greater than 1 in terms of absolute value, the mean angle satisfying the relationship 13+131*exp(L/100)<<28+110*exp(L/100), the reinforcing elements of the carcass reinforcement being cords which, in the test referred to as the permeability test, yield a flow rate of less than 20 cm.sup.3/min, a rubber compound being present within the cords, and, in the sidewall of the tire, the profile of the outer surface of the tire is at a constant distance from the carcass reinforcement layer between the points F and A, and meets the outer surface of the bead at the point C, forming two successive circular arcs.

Provided is a steel cord for reinforcing a rubber article which can further improve cut resistance when applied to a tire while maintaining the amount of steel to be used. A steel cord for reinforcing a rubber article comprising: one core strand 11 having a two-layered layered-twisted structure formed by twisting a plurality of steel filaments 1; and a plurality of sheath strands 12 having a layered-twisted structure formed by twisting a plurality of steel filaments 2, wherein the sheath strands are twisted around the core strand. A ratio dc/ds of a diameter dc of a sheath filament constituting the sheath of the core strand to a diameter ds of an outermost layer sheath filament constituting the outermost layer sheath of the sheath strand is more than 1.25 and not more than 1.50.

A resin-metal composite member for a tire comprises a metal member (27) and a coating resin layer (28) that covers the metal member (27) and contains a resin composition. The resin composition includes a thermoplastic elastomer, at least one additive resin selected from an amorphous resin having an ester bond or a polyester-based thermoplastic resin, and at least one chemical selected from a carbodiimide compound, a polyfunctional epoxy compound, or a polyfunctional amino compound.

Provided is a steel cord for reinforcing a rubber article which can further improve cut resistance when applied to a tire. Provided is a steel cord for reinforcing a rubber article including: one core strand 11 having a layered-twisted structure formed by twisting a plurality of steel filaments 1; and a plurality of sheath strands 12 having a layered-twisted structure formed by twisting a plurality of steel filaments 2, wherein the sheath strands are twisted around the core strand. A ratio S1/S of the sum S1 of cross-sectional areas of outermost layer sheath filaments constituting an outermost layer sheath of the core strand to the sum S of cross-sectional areas of all filaments constituting the core strand is from 0.69 to 0.74, and a ratio Ps/P of the sum Ps of strengths of the sheath strands to strength P of the cord as a whole is from 0.81 to 0.85.

A pneumatic tire comprises a carcass layer, a belt layer disposed on the outer side in the tire radial direction of the carcass layer, and tread rubber disposed on the outer side in the tire radial direction of the belt layer. The belt layer is formed by laminating a pair of cross belts having belt angles with an absolute value from 10 to 45 both inclusive and mutually opposite signs, and a circumferential reinforcing layer having a belt angle within a range of 5 relative to the tire circumferential direction. The distance (Gcc) from the tread profile to the tire inner circumferential surface along the tire equatorial plane and the distance (Gsh) from the tread edge to the tire inner circumferential surface have a relationship satisfying 1.10Gsh/Gcc. The groove depth (Dsh) and under-groove gauge (UDsh) of the outermost circumferential main groove have a relationship satisfying 0.20UDsh/Dsh.

The present disclosure relates to an electroplated bead wire having excellent oxidation resistance, of which oxidation resistance and aging adhesive strength with tire rubber are improved by forming a copper- and cobalt-plated layer by electroplating. The electroplated bead wire includes the plated layer formed through electroplating, wherein the plated layer contains 40 to 99 wt % of copper and 1 to 40 wt % of cobalt.

A tire comprises at least first and second working plies (16, 18) respectively comprising first and second reinforcing elements (50, 52) in which at least one of the following relationships is satisfied:

3324E1+3650(D1.sup.4d11000)/E13998E1+4547(I)

3324E2+3650(D2.sup.4d21000)/E23998E2+4547(II)

where D1, D2 are the diameter of each reinforcing element (50, 52) made up of a metallic monofilament (66, 68), with D1 and/or D2 ranging from 0.25 to 0.38 mm, d1, d2 are the density of the reinforcing elements (50, 52), expressed in monofilaments per decimetre, and E1, E2 are the mean thickness of the working ply (16, 18), expressed in mm.

A process for synthesizing polyamide PA 6-6, including a first step of reacting, in the presence of water, a compound of R.sub.0COO(CH.sub.2).sub.4COOR.sub.0 in which R.sub.0 and R.sub.0, which may be identical or different, represent H or a linear or branched alkyl radical comprising from 1 to 4 carbon atoms, with hexamethylenediamine (HMDA), at a temperature of less than or equal to 160 C., to form a reaction medium, and then a second step of heating the reaction medium to a temperature of greater than or equal to 200 C.; the reaction medium also including a compound of R.sub.1COO(CH.sub.2).sub.nCHCH(CH.sub.2).sub.nCOOR.sub.2 and/or a compound of R.sub.3(CH.sub.2).sub.mCHCH(CH.sub.2).sub.nCOOR.sub.4.

In accordance with the invention, a ply coat rubber composition for a tire ply comprises from 60 phr to 90 phr of natural rubber, from 10 phr to 40 phr of synthetic polyisoprene, from 30 phr to 80 phr of pre-silanized and precipitated silica, from 0.1 phr to 5 phr of a cobalt salt, up to 15 phr of carbon black, up to 5 phr of resin, and up to 8 phr of oil. Moreover, the invention is directed to a tire comprising such a rubber composition.