A nylon 6.6 yarn suitable for a tire cord reinforcement for pneumatic tires includes higher than 12,0 g/dtex Tensile Reinforcement Index (TRI) and tenacity between 9,3 g/dtex-10,5 g/dtex, where the TRI is defined as: TRI (g/dtex)=Tenacity (g/dtex) +Stress at 7% Elongation. The nylon 6.6 yarn is suitable for using as tire cord reinforcement in pneumatic tires.

A carcass layer of a pneumatic lire includes carcass cords of organic fiber cords obtained by intertw ining a filament bundle of organic fibers, and includes turn-up portions formed by turning back end portions of the carcass layer at bead portions toward an outer side in a width direction. The carcass cords have an elongation at break (EB) satisfying EB≥15%. An averagetotal gauge (GC)of a center land portion located within a width of 10% of a width of a second widest belt in a belt layer on right and left sides of an equatorial plane in the width direction, an average thickness(SG) of a sound absorptive member inside the pneumatic tire and located within a range identical to that of the center land portion, and the elongation at break (EB) of the carcass cords satisfy 15≤GC/(GC+SG/10)×EB (%)≤25.

A tire (1) for a heavy construction plant vehicle with satisfactory compromise between the breaking strength of its circumferential hoop reinforcement (7), having an axial width LF and having a circumferential hooping layer (71, 72) with elastic metallic reinforcers having a structural elongation AS and a force at break FR, and forming an angle at most equal to 5° with the circumferential direction (XX), and the endurance of its working reinforcement (6), formed by two working layers (61, 62) with inextensible metallic reinforcers, the mean angle AM of which with the circumferential direction (XX′) is at least equal to 15° and at most equal to 45°. The axial width LF, the structural elongation As, the force at break Fr and the mean angle AM satisfy the relationship:

Zn/Z0*(T0+(a1+a2*As)/AM+b*LF*(AM−A0)/A0+c*AM)<Fr/CS, where Zn is the nominal load, Z0=100 t, T0=7000 N, a1=−230,000 N*°, a2=−160,000 N*°/%, b=−34,000 N/m, A0=29°, c=550 N/°, CS>=1.

A tire for a heavy-duty vehicle of construction plant type comprises a crown reinforcement (35) radially on the inside of a tread (10) and radially on the outside of a carcass reinforcement (50). The crown reinforcement (35) comprises: at least one “low-modulus” layer (20) formed of elastic metal reinforcers having a structural elongation at least equal to 0.4%, and a total elongation at break at least equal to 3%, and a tensile elastic modulus of between 40 GPa and 130 GPa; at least one “rigid” layer (30) formed of rigid metal reinforcers, the structural elongation of which is less than or equal to 0.2% and the tensile elastic modulus of which is between 140 GPa and 200 GPa. The ratio of the breaking tension of the rigid layer to that of the low-modulus layer is greater than or equal to 1.2.

Provided is a steel cord for rubber article reinforcement, which has both the tensile strength in the cord axial direction and the strength in the shear direction at higher levels. A steel cord (10) for rubber article reinforcement includes: a single core strand (11) having a layer-twisted structure; and plural sheath strands (12) each having a layer-twisted structure, and the sheath strands (12) are twisted around the core strand (11). In the sheath strands (12), a ratio between the diameter of a core filament (12a) and the diameter of a sheath filament (12b) is 0.75 to 0.85, and a ratio between the strength of the core filament (12a) and the strength of the sheath filament (12b) is 0.55 to 0.7.

A cord for reinforcing elastomers excellent in adhesion to elastomers such as rubber is provided. The cord is a cord for reinforcing elastomers (10) that includes metallic filaments (1) and a resin filament (2) twisted together, the resin filament (2) being made from a polymeric material having a melting point or softening point of 80 to 160° C. The cord for reinforcing elastomers includes a core and at least one sheath layer, wherein, after vulcanization, a distance w between metallic filaments (1b) forming an outermost sheath layer is 100 μm or less, and, on a cross section of the cord taken along a direction orthogonal to an axial direction, a filling ratio, which is a ratio of an area of a polymeric material (3) derived from the resin filament (2) to a gap region is 52 to 120%, where the gap region is defined as a portion occupied by a material other than the metallic filaments (1) within a region formed by connecting the centers of the individual metallic filaments (1b) constituting the outermost sheath layer.

The outer diameter of the pneumatic tire is 350 mm or more and 600 mm or less, and the tire width is 125 mm or more and 255 mm or less. An aspect ratio of the pneumatic tire is 40% or more and 75% or less, a rim diameter of a rim wheel is 10 inches or more and 22 inches or less, and a rim width of the rim wheel is 3.8 inches or more and 8 inches or less. The pneumatic tire satisfies the relationship of 0.78≤RW/SW≤0.99 and 0.56≤RD/OD≤0.75. The carcass has a plurality of carcass cords arranged at intervals, the carcass cords are formed of prescribed organic fibers, and the breaking strength of the carcass cords is ≥2.2 kN/cm.

In a pneumatic tire including a carcass layer mounted between a pair of bead portions and a belt reinforcing layer disposed on an outer circumferential side of the carcass layer, the carcass layer is formed of a carcass cord made of an organic fiber cord, an elongation at break of the carcass cord is set to 20% or more, an elongation under a load of 1.5 cN/dtex of the carcass cord on the inner circumferential side of the belt layers is set to from 5.5% to 8.5%, the belt reinforcing layer is formed of a cover cord made of an organic fiber cord, and a tensile strength of the cover cord per width of 50 mm at a 3.0% elongation is set to from 2.8 kN to 4.0 kN.

The present invention relates to a polyester tire cord made of polyester yarn and having a 5% LASE of 1.2 g/d or more as measured according to ASTM D885 at 80° C., a 5% LASE of 1.0 g/d or more as measured according to ASTM D885 at 120° C., and a toughness retention rate of 65% or more at 80° C. and 120° C. The tire cord of the present invention has a modulus comparable to that of rayon even in a high-temperature environment at 120° C. or higher, and has excellent dimensional stability and heat resistance, and thus it can be advantageously applied to a high-performance tire.

Provided is a steel cord for rubber article reinforcement which has excellent corrosion resistance and productivity without deterioration of adhesion with rubber. A steel cord (1) for rubber article reinforcement, in which plural steel filaments (2) are twisted together, includes: a core having at least one core filament (2c); and a sheath having at least one sheath layer formed by twisting at least one sheath filament (2s) around the core. In this steel cord (1), brass plating is performed on the steel filaments (2) and zinc plating is further performed on the outer circumference of the brass plating of the core filament (2c), and the steel filaments (2) have a diameter d of 0.1 mm to 0.6 mm.