The present invention relates to a novel tire cord reinforcement made of ultra high modulus aramid fibers which has bi-elastic tensile properties. The cord includes at least two plies, and there is a spacing between the cord plies. The cord twisting improves bending and compression fatigue resistance of the aramid, but at the same time reduces the modulus and strength too.

The present invention provides a tire improved in the run flat durability, having at least one member selected from the group consisting of a side reinforcing rubber layer and a bead filler using a rubber composition comprising a rubber component containing 20% by mass or more of a modified conjugated diene based polymer, satisfying Expression (1) in terms of the elongation X under a stress of 6.5 MPa at 180 C. and the elongation Y under a stress of 6.5 MPa at 25 C. after vulcanization.
1.00X/Y1.15(1)

The invention relates to a polyamide cord for use as carcass strength member in a pneumatic vehicle tire, wherein the polyamide cord has a residual shrinkage in the range from 0% to 2% and a shrinkage at 180 C. in the range from 0% to 4.5%, where the residual shrinkage of the polyamide cord and the shrinkage at 180 C. of the polyamide cord are determined to ASTM D 855. The invention also relates to a pneumatic vehicle tire comprising one or more polyamide cords and to a process for producing one or more polyamide cords, to a process for producing a rubberized reinforcement ply and to a process for producing a pneumatic vehicle tire.

A pneumatic tire containing a polyester (e.g., polyethylene terephthalate or polyethylene naphthalate) derived from a non-fossil raw material. In a preferred embodiment, a polyester (e.g., polyethylene terephthalate or polyethylene naphthalate) in which a linear or cyclic moiety is produced using a raw material derived from a non-fossil raw material is used in the pneumatic tire. A pneumatic tire in which polyethylene terephthalate or polyethylene naphthalate produced using a raw material derived from a non-fossil raw material is used as a carcass material or a belt reinforcing material.

The present invention relates to a novel tire cord reinforcement made of ultra high modulus aramid fibers which has bi-elastic tensile properties. The cord includes at least two plies, and there is a spacing between the cord plies. Such a novel bi-elastic tire cord improves high speed durability and eliminates flatspotting when used as carcass reinforcement in pneumatic radial and bias tires.

In a pneumatic tire, a carcass layer mounted between bead portions includes composite cords made of polyethylene terephthalate fiber yarn having a fineness from 420-1200 dtex and an aromatic polyamide fiber yarn having a fineness from 520-1200 dtex, and a total fineness from 940-2400 dtex, and a twist coefficient from 1600 to 2400, the composite cords having an intermediate elongation from 2.0% to 4.5% with a load of 2.0 cN, having a dimensional stability index from 2.5% to 6.0% which is a sum of a dry heat shrinkage rate at 150 C. and the intermediate elongation with the load of 2.0 cN, and having a ratio of an initial elastic modulus at 100 C. within a load range from 0 N to 44 N with respect to an initial elastic modulus at 25 C. within a load range from 0 N to 44 N, the ratio being from 76% to 94%.

The invention relates to a rubberized reinforcing ply for articles made of elastomeric material, preferably for pneumatic vehicle tires, where the reinforcing ply has a multitude of strength members which are arranged in parallel and spaced apart, where each strength member consists of at least one twisted multifilament yarn composed of polyethylene terephthalate (PET), where the multifilament yarn has a yarn count (linear density) of 50 to 1100 dtex and a linear density-based ultimate tensile strength of 70 cN/tex in accordance with ASTM D885-16, and where the rubberized material has a thickness D. The invention further relates to a pneumatic vehicle tire comprising this reinforcing ply.

The multifilament yarn has an elongation at break of 10% to 20% in accordance with ASTM D885-16, a crystallinity determined via DSC of 55% to 65% and a birefringence n with 0.21n0.25.

The reinforcing element (45) comprises an assembly (49) made up: of a multifilament strand made of aromatic polyamide or aromatic copolyamide (46) and of a multifilament strand made of polyester (48). The two strands (46, 48) are wound in a helix around one another, and the reinforcing element (45) is twist-balanced. The twist factor K of the reinforcing element (45) ranges from 5.5 to 6.5 where K is defined by the formula: K=(RTi.sup.1/2)/957 in which R is the twist of the reinforcing element (45) expressed in twists per metre and Ti is the sum of the counts of the multifilament strands of the reinforcing element (45) in tex.

Provided are a pneumatic tire with improved dimensional stability, low loss property, and durability and a method of producing the same. In a pneumatic tire, a rubber-fiber composite is used in at least any of a carcass ply and a cap ply, the rubber-fiber composite containing: a fiber cord made of polyamide multifilament fibers having a glass transition temperature in a range of 150 C. to 200 C.; and a rubber, a layer made of a resorcin-formalin-latex adhesive is formed at an interface between the fiber cord and the rubber, and a thermal contraction stress at 177 C. of the fiber cord with the layer formed thereon is 0.01 cN/dtex to 0.2 cN/dtex.

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 in sidewall portions is set to from 5.0% to 8.0%, 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.