A pneumatic radial tire includes belt layers disposed on an outer circumferential side of a carcass layer in a tread portion. The belt layers are formed of steel cords in a N+M structure in which the number of wire strands N of an inner layer is 2 to 4 and the number of wire strands M of an outer layer is 2 to 7. A twist direction of the inner layer is different from a twist direction of the outer layer. The steel cords are inclined with respect to a tire circumferential direction to intersect each other in layers of the belt layers. A belt cover layer disposed on an outer circumferential side of the belt layers is formed of organic fiber cords having elongation of 2.0% to 4.0% under 2.0 cN/dtex load. The organic fiber cords are wound spirally along the tire circumferential direction.

The invention relates to a hybrid cord for use as a reinforcement in a belt bandage of a pneumatic vehicle tire, consisting of at least two threads with ends which are twisted together. At least one first thread is a high-modulus thread with a specified thread fineness, and another thread is a low-modulus thread, said other low-modulus thread having a lower thread fineness than the first thread. The invention is characterized in that the proportion of the high-modulus thread in the hybrid cord is 80-95 wt. %; the difference between the thread fineness of the high-modulus thread and the thread fineness of the other low-modulus thread is >800 dtex; and the elongation at break of the high-modulus thread ranges from 1%-8%, and the elongation at break of the low-modulus thread ranges from 9%-30%.

The present disclosure relates to a method for manufacturing a hybrid tire cord that utilizes a difference in fineness, and thereby can be more easily manufactured in a form covered with aramid, has uniform physical properties, and improves tire performance.

A steel cord includes one or more core filaments, and outer sheath filaments provided so as to surround the one or more core filaments. The one or more core filaments and the outer sheath filaments have an identical wire diameter and an identical twist pitch. At least one of the one or more core filaments is a waved filament having a bent portion and a non-bent portion along a longitudinal direction.

In a pneumatic tire, a belt cover layer is provided on an outer circumferential side of a belt layer in a tread portion and includes organic fiber cords helically wound along a tire circumferential direction. As the organic fiber cord, a polyethylene terephthalate fiber cord is used which has a single yarn size fineness of 700 dtex or less and in which the number of twists is 30 twists or more/100 mm. A layer thickness of the belt cover layer is 1.6 times or more as large as a cord diameter of the organic fiber cord.

The method allows the manufacture of at least first and second assemblies (26, 28) of M1 filamentary elements and M2 filamentary elements, at least one of the first and second assemblies (26, 28) comprising several filamentary elements (14) wound together in a helix.

The method comprises a step of assembling M filamentary elements (14) together into a layer of the M filamentary elements (14) around a temporary core (16) to form a temporary assembly (22), and a step of splitting the temporary assembly (22) into at least the first and second assemblies (26, 28) of M1 filamentary elements and M2 filamentary elements.

A tire reinforcement fabric is woven with predipped and heat-set single cords as warp bound together with weft materials, and a pneumatic tire includes a tire reinforcement fabric. The tire reinforcement fabric is obtained by weaving individually dipped cords as warp material and a plurality of any kind of weft materials.

Provided is an elastomer reinforcement cord with improved rust inhibition. An elastomer reinforcement cord (10) includes metal filaments and a polymer material. The elastomer reinforcement cord (10) has a multi-strand structure which includes: at least one core strand (21) formed by twisting plural metal filaments (1a) and (1b) together; and two or more sheath strands (22) each formed by twisting plural metal filaments (11a) and (11b) together, and in which the sheath strands are twisted together around the core strand. In a region surrounded by a line connecting the centers of the metal filaments constituting the outermost sheath layer of the core strand at a cross-section in a direction orthogonal to an axial direction after vulcanization of the core strand, when a region occupied by other than the metal filaments is defined as a gap region, a filling rate, which is a ratio of the area of the polymer material with respect to the gap region, is 52% to 120%.

Provided is an elastomer reinforcement cord in which the problem of stress concentration at an interface between an elastomer and a metal cord is solved and the durability is thereby improved. The elastomer reinforcement cord includes metal filaments (1a) and (1b), and a polymer material (3) having a melting point or softening point of 80° C. to 160° C. The elastomer reinforcement cord has a core (11) and at least one sheath layer (12). In a region surrounded by a line connecting the centers of the metal filaments constituting the outermost sheath layer at a cross-section in a direction orthogonal to an axial direction after vulcanization, when a region occupied by other than the metal filaments is defined as a gap region, the polymer material is contained in this gap region, and a filling rate, which is a ratio of the area of the polymer material, is higher than 120%, taking the area of the gap region as 100%.

Provided is an elastomer reinforcement cord with improved rust resistance. An elastomer reinforcement cord 10 includes metal filaments and a polymer material. The elastomer reinforcement cord 10 has a multi-strand structure which includes: at least one core strand 21 formed by twisting plural metal filaments 1a and 1b together; and two or more sheath strands 22 each formed by twisting plural metal filaments 11a and 11b together, the sheath strands being twisted together around the core strand. An intra-sheath-strand filling rate a, which is a ratio of the area of the polymer material with respect to an intra-sheath-strand gap region A, is 52% or higher, and an inter-strand filling rate b, which is a ratio of the area of the polymer material with respect to an inter-strand gap region B, is 75% or higher.