Pneumatic vehicle tires with carcass

Abstract

The present invention relates to a pneumatic vehicle tire having a carcass, wherein the carcass has at least one carcass ply having a strength member, and the strength member takes the form of a tire cord containing at least one polyester yarn made of at least 90 mol% polyethylene terephthalate (PET). The strength member of the carcass is intended to provide sufficient tire stability and durability over a wide range of fineness, particularly at high speeds, and to enable weight reduction of the tire. This is achieved by having a tire cord with a breaking strength of at least 8.0 g / den, a LASE@2% of at least 1.1 g / den, a LASE@5% of up to 2.5 g / den, a breaking energy of at least 183 (g / den)·mm, and a sidewall indentation value of up to 5%.

Description

Technical Field

[0001] The present invention relates to a pneumatic vehicle tire comprising a carcass extending from one bead region to the other bead region and fixed there by winding a high-tensile bead core, the carcass including at least one carcass ply having strength members arranged in parallel and spaced apart from each other and embedded in an elastomeric material, the strength members being in the form of a tire cord including at least one polyester yarn containing at least 90 mol% of polyethylene terephthalate (PET) in each case.

Background Art

[0002] A pneumatic vehicle tire generally comprises an air-impermeable inner layer, a strength member-containing carcass extending from the top region of the tire through the sidewall to the bead region and fixed there by winding a high-tensile bead core, a profiled tread arranged radially outside, and a belt bandage arranged between the tread and the carcass.

[0003] The carcass has one or more carcass plies.

[0004] The strength members of the carcass ply are embedded in a rubber mixture in a manufacturing process, for example, by calendering, and can be used in a tire as a rubberized strength member ply. The carcass must exhibit sufficient strength so as to sufficiently absorb the forces generated during the running of the tire and be able to exhibit long life. The carcass provides resistance particularly against the internal pressure of the tire. The strength members of the carcass are typically arranged at a small angle of up to 10° with respect to the radial direction in the sidewall region.

[0005] It is known that polyester tire cords are used as the strength components of the carcass. The cord is formed by twisting together two or more polyester multifilament threads from the ends. Cords made of high-elasticity, low-shrinkage PET (HMLS PET) have been shown to be particularly suitable. For example, it is known that HMLS PET 2000 den x 2 and 3000 den x 2 are used in the carcass.

[0006] Tire cords are manufactured using industrial yarns, such as polyester yarn. Roughly speaking, polyester yarn can be manufactured by melting polyester granules, extruding the molten polyester using a spinneret to form filaments, cooling the semi-solid filaments extruded from the spinneret, bundling the cooled filaments, stretching them, and winding them up.

[0007] Optimizing rolling resistance is the focus of current efforts. For this purpose, it is advantageous to use the thinnest possible strength components. However, the strength components of the carcass must continue to meet various requirements, even if their denier and, consequently, their diameter are reduced. The tire must continue to meet requirements for stability and durability, particularly at high speeds.

[0008] When reducing the fineness of carcass strength members, the requirements for physical properties such as tensile strength, modulus of elasticity, toughness, and shrinkage rate must also be met. However, this has not yet been achieved with current commercially available strength PET strength members or their manufacturing processes. [Overview of the project] [Problems that the invention aims to solve]

[0009] The object of the present invention is to provide a pneumatic vehicle tire equipped with a carcass strength member that provides sufficient stability and durability over a wide range of fineness, particularly sufficient stability and durability at high speeds, and that enables weight reduction of the tire. [Means for solving the problem]

[0010] This is because the tire code is determined in each case according to the ASTM-D-885 standard test method. • Tensile strength of at least 8.0 g / den, • At least 1.1 g / den LASE@2%, • LASE@5% of up to 2.5g / den • Toughness of at least 183 (g / den)·mm, • Sidewall indentation (SWI) value of 5% or less, preferably 4% or less, and particularly preferably 3.6% or less. It has, Sidewall indentation (SWI) is given by the following formula 1: [Formula 1] SWI(%)=[(D)-(C)]+[(A)-(B)] Given by, in equation 1: (A) is the residual shrinkage rate of the tire cord, measured after the thermal shrinkage rate is determined using a shrinkage tester (sample length 250 mm, 180°C, exposure time 2 minutes, initial load 20-45 g), followed by 1 minute of cooling. (B) is the residual shrinkage rate of the tire cord, measured after the thermal shrinkage rate is determined using a shrinkage tester (sample length 250 mm, 180°C, exposure time 2 minutes, initial load 40-90 g), followed by 1 minute of cooling. (C) is the elongation of the tire cord under a load of 1.5 to 3.0 kg, as measured according to the ASTM-D-885 standard test method. (D) is the elongation of the tire cord under a load of 3.0–6.0 kg, measured according to the ASTM-D-885 standard test method. This is achieved in certain cases. [Brief explanation of the drawing]

[0011] [Figure 1] This shows a polyester yarn manufacturing apparatus. [Modes for carrying out the invention]

[0012] Tensile strength is the tensile strength related to fineness (measured in grams / denier). Tensile strength, LASE@2%, LASE@5%, and toughness can be measured in each case according to the ASTM-D-885 standard test method.

[0013] The term "greater than or equal to" should be understood as meaning "at least." Therefore, a quantity encompassing a value greater than or equal to a certain value should be understood as containing at least that value. The expression "less than or equal to" should be understood as meaning "at most." Therefore, a quantity encompassing a value less than or equal to a certain value should be understood as containing at most that value.

[0014] Physical measurements, particularly those of the tire cord and / or the raw cord and / or the polyester yarn of the tire cord, can be taken before the tire cord is embedded in the carcass ply of a pneumatic vehicle tire.

[0015] As a result, surprisingly, a lightweight tire cord is provided that achieves not only high tensile strength, high modulus of elasticity, and low shrinkage, but also high elongation at break. Such a tire cord is very suitable as a structural member for the carcass.

[0016] Therefore, the present invention provides a pneumatic vehicle tire equipped with a carcass strength member that can provide the tire with sufficient stability and durability over a wide range of fineness, particularly sufficient stability and durability at high speeds, and also achieve weight reduction of the tire.

[0017] The polyester yarn contains at least 90 mol% PET and therefore has a PET content of at least 90 mol%. Thus, the polyester yarn is formed entirely or partially from PET. The polyester yarn may have a PET content of 92 mol% or more, preferably 95 mol% or more, and particularly preferably 99 mol% or more. The polyester yarn may be formed from 100 mol% PET.

[0018] The tire cord according to the present invention can be produced by a method including a step of spinning molten polyester granules containing 90 mol% or more of PET and having an intrinsic viscosity of 1.0 dl / g or more using a spinning package including a spinneret having a nozzle unit to produce a polyester yarn; a step of producing a green cord using the polyester yarn; and a step of heat-treating the green cord after dipping it in an adhesive solution.

[0019] The step of producing the yarn can particularly include extruding the polyester granules through a spinneret including a nozzle unit having a shear rate of 220 to 260 1 / s and a polymer extrusion rate of 2.0 m / min or less under a spinning package pressure of 1800 to 2500 psi to form a polyester multifilament including polyester single filaments having a fineness of 2.5 to 3.5 den (denier).

[0020] The tire cord obtained by the method for producing a tire cord has a tensile strength of 8.0 g / den or more, LASE@2% of 1.1 g / den or more, LASE@5% of 2.5 g / den or less, and a toughness of at least 183 (g / den)·mm or more, each determined according to the ASTM-D-885 standard test method, and can achieve a sidewall indentation (SWI) value of 3.6% or less.

[0021] The polyester multifilament includes 200 to 2000 individual filaments of polyester having a fineness of 2.5 to 3.5 den.

[0022] The process of manufacturing polyester yarns further includes extruding molten polyester granules having an intrinsic viscosity of 1.0 dl / g or more through a spinneret including a nozzle unit having a shear rate of 220 to 260 1 / s and a polymer extrusion rate of 2.0 m / min or less under a spinning package pressure of 1800 to 2500 psi to produce a plurality of filaments; heating the extruded plurality of filaments by a heating unit; cooling the heated filaments by a cooling unit; bundling the plurality of filaments to form a polyester multifilament; stretching the polyester multifilament; and winding up the stretched multifilament.

[0023] The process of stretching the polyester multifilament may include stretching the polyester multifilament at a total draw ratio of 1.0 to 3.0.

[0024] Although a low DPF (denier / filament) is adopted in the production of polyester yarns, according to the present disclosure, it is possible to adjust the polymer extrusion rate at the nozzle to achieve high spinning tension and high draw while establishing a high extrusion pressure from the spinning package to maintain a high shear rate at the nozzle. As a result, extremely excellent mechanical properties of the polyester yarns in the tire cord are maintained, and all the properties required for weight reduction can be realized.

[0025] Therefore, the disclosure according to the present disclosure enables the production of a tire including a lightweight tire cord that realizes not only high tensile strength, high modulus of elasticity, and low shrinkage rate but also high elongation at break.

[0026] This method is suitable for maintaining excellent mechanical and physical properties of polyester yarn, such as tensile strength and elongation, by incorporating polyester yarn produced using a process for spinning high-count multifilaments that achieve spinning conditions of low denier / filament, low nozzle extrusion rate, and low shear rate, and by adjusting the pressure of the spinning package. Experiments have shown that by introducing polyester yarn according to the above method, it is possible to produce high-strength tire cords that exhibit all physical properties of high modulus of elasticity and high toughness. This disclosure is based on these findings.

[0027] Tire cord is manufactured through a three-stage process consisting of yarn production, a twisting process using the yarn, and heat treatment. In order to obtain a product with superior performance, it is necessary to maintain the above-mentioned physical properties of the yarn in the tire cord.

[0028] This means that the yarn undergoes post-processing known as twisting and heat treatment, at which point its physical properties are impaired and altered. For example, a decrease in strength and toughness may occur, and shrinkage and elongation properties may also change. Therefore, it is necessary to maintain the physical properties of the yarn during the post-processing stages.

[0029] For the intended weight reduction, the tire cord must satisfy all three physical properties: high modulus of elasticity, high toughness, and low, stable shrinkage, in order to replace the existing fineness range.

[0030] According to the present invention, the factor indicating the modulus of elasticity is LASE (load at a specific elongation), and the factor indicating shrinkage is sidewall indentation (SWI). Furthermore, in order to obtain high toughness, it is necessary to adjust the modulus of elasticity so that it is low over a specific range. This means that even if the modulus of elasticity increases, it is necessary to avoid the deterioration of other physical properties, such as toughness. For example, it is necessary to control LASE@5%, which is the magnitude of the modulus of elasticity determined by the load (g / den) at the point in elongation corresponding to 5% in the tensile load curve obtained by the ASTM-D-885 measurement method.

[0031] Conventional tire cords cannot achieve all three physical properties, but the cord of this embodiment exhibits high tensile strength even after post-processing of the yarn, and achieves all properties of excellent modulus of elasticity, excellent toughness, and excellent shrinkage rate.

[0032] Such tire cords can be obtained by incorporating polyester yarns produced by adjusting the pressure of the spinning package along with the spinning process for high-count multifilaments.

[0033] The manufacturing conditions for the yarn, in particular, employ a spinning process for high-count multifilaments, which means that a low denier / filament (DPF), a low nozzle extrusion rate, and a low shear rate at the nozzle are used. However, such manufacturing conditions can lead to a decrease in the toughness of the tire cord and a decrease in the pressure within the spinning package / spinneret.

[0034] This means that while the spinning process for high-count multifilaments enables the high strength, high modulus of elasticity, and stable shrinkage properties of tire cord, it comes at the cost of reduced toughness (elongation at break). This is because these properties are inversely related. Therefore, if spinning is carried out using conventional processes, it is extremely difficult to achieve a tire cord that possesses all the desired physical properties.

[0035] Therefore, in this specification, the present invention has conceived of maintaining high toughness by using specific spinning conditions when applying a spinning process for high-count multifilaments by simultaneously adjusting the pressure of the spinning package. In addition, this toughness limits the elastic modulus range LASE@5% to a specific range.

[0036] The tire cord manufactured by the above method achieves all of the aforementioned properties, including high strength, high modulus of elasticity, low thermal shrinkage, and high elongation, while maintaining the excellent physical properties of the yarn. This makes it possible to produce lightweight tires with advantageous rolling resistance.

[0037] Therefore, rolling resistance can be improved by lowering the fineness of the tire cord (for example, from 2000 den to 1500 den, or from 3000 den to 2000 den).

[0038] It is also possible to improve the physical properties of the tire, which would normally be compromised if the fineness of the tire cords were reduced.

[0039] In an advantageous embodiment, the LASE@2% value of the tire cord is 1.15 g / den or greater, preferably 1.20 g / den or greater, where the force is measured at 2% elongation. In an advantageous embodiment, the LASE@2% value of the tire cord is 1.5 g / den or less, preferably 1.45 g / den or less, particularly preferably 1.4 g / den or less. The LASE@2% value of the tire cord may be between 1.1 and 1.5 g / den.

[0040] In advantageous embodiments, the LASE@5% value of the tire cord is 2.45 g / den or less, preferably 2.45 g / den or less. In advantageous embodiments, the LASE@5% value of the tire cord is 2.0 g / den or more, preferably 2.05 g / den or more, particularly preferably 2.1 g / den or more. The LASE@5% value of the tire cord may be between 2.0 and 2.5 g / den.

[0041] In advantageous embodiments, the toughness of the tire cord is 200 (g / den)·mm or more, preferably 210 (g / den)·mm or more, as determined according to the ASTM-D-885 standard test method. In advantageous embodiments, the toughness of the tire cord is 300 (g / den)·mm or less, preferably 280 (g / den)·mm or less, particularly preferably 250 (g / den)·mm or less, as determined according to the ASTM-D-885 standard test method. The toughness of the tire cord may have values ​​between 183 (g / den)·mm and 300 (g / den)·mm.

[0042] The sidewall indentation value (SWI value) of the tire cord may be 3.55% or less, preferably 3.4% or less. The sidewall indentation value (SWI value) of the tire cord may be 3.0% or more, preferably 3.1% or more, particularly preferably 3.2% or more, and very preferably 3.3% or more. The SWI value of the tire cord can be 3.0% to 3.6%.

[0043] In an advantageous embodiment, the tire cord has a breaking strength of 8.0 g / den to 11 g / den, a LASE@2% value of 1.1 to 1.5 g / den, a LASE@5% value of 2.0 to 2.5 g / den, a toughness of 183 (g / den)·mm to 300 (g / den)·mm, and an SWI value of 3.0% to 3.6%.

[0044] In this specification, the residual shrinkage rate before cooling for (A) and (B) can be the ratio between the length (L0) measured after conditioning a 250 mm tire cord sample at 25°C and 65% relative humidity for 24 hours with an initial tensile load selected from that range, and the length (L1) measured after processing at 180°C for 2 minutes under an initial tensile load of 0.011 g / den using a shrinkage tester. This means that the shrinkage rate ΔL1 can be defined as the rate of change in the length of the sample {=[(L0-L1) / L0]×100}. L0 and L1 can each be measured five times. Furthermore, the residual shrinkage rate after cooling can also be determined by ΔL2 ({=[(L1-L3) / L1]×100}), where L3 is the length after cooling at room temperature for 1 minute.

[0045] Furthermore, by appropriately adjusting the load range within the above range according to the fineness of the tire cord, regardless of fineness, the tensile loads of (A) and (B), and the loads of (C) and (D) can be measured.

[0046] This means that SWI is not limited to the fineness range of the tire cord, but can be measured by adjusting the load range according to the conditions of different fineness ranges and determining the average value. In particular, SWI can be defined and adjusted as a load depending on the fineness of the tire cord.

[0047] In one embodiment of the present disclosure, the tire cord may include a raw cord having a total fineness of 1000 to 6000 den. The initial tension range can be adjusted according to the total fineness of the raw cord present in the tire cord, which is set according to the manufacturing conditions of the yarn.

[0048] Therefore, according to embodiments of the present disclosure, when the total fineness of the tire cord is set in the range of 3000 denier to 4000 den, the preload for measuring the residual shrinkage rate (A) can be set to 35 to 45 g, the preload for measuring the residual shrinkage rate (B) can be set to 70 to 90 g, the load for measuring the elongation (C) can be set to 2.3 to 3.0 kg, and the load for measuring the elongation (D) can be set to 4.6 to 6.0 kg.

[0049] When the total fineness of the tire cord is set to 2000 denier, 2600 denier, 3000 denier, or 4000 denier, the preload for measuring the residual shrinkage rate (A) may be 20g, 30g, 35g, or 45g. The preload for measuring the residual shrinkage rate (B) under the aforementioned denier conditions may be 40g, 60g, 70g, or 90g. Furthermore, the load for measuring (C) under the above denier conditions may be 1.5kg, 2.0kg, 2.3kg, or 3.0kg. In addition, the load for measuring (C) under the above denier conditions may be 3.0kg, 4.0kg, 4.6kg, or 6.0kg.

[0050] Furthermore, the residual shrinkage rate may be the average of at least three, preferably at least four, and particularly preferably at least five values ​​in each load range.

[0051] In advantageous embodiments, the tire cord has a thermal shrinkage coefficient of less than 4%, preferably less than 3%, and particularly preferably less than 2.5%, as determined according to the ASTM-D-885 standard test method.

[0052] In a favorable embodiment, in Equation 1, (A) is 1.0% to 3.2%, (B) is 0.7% to 2.8%, (C) is 1.3% to 1.7%, and (D) is 4.2% to 4.6%.

[0053] In an advantageous embodiment, the carcass ply has a ply strength of at least 0.94 kg / dm / den.

[0054] Reinforcement in specific areas of a tire is crucial to tire performance. Therefore, ply strength normalized by the fineness of the reinforcing members is important for reducing tire weight. High ply strength enables superior tire reinforcement. Consequently, for superior tire reinforcement, it is necessary to use high-strength tire cords and increase the density of the tire cords by optimizing the distance between them.

[0055] Therefore, increasing the ply strength to 0.94 kg / dm / den or higher improves tire performance. Ply strength can be determined by multiplying the tensile strength of the tire cord according to the ASTM-D-885 standard test method by the density of the tire cords within the ply and normalizing it by the fineness of the tire cords.

[0056] In an advantageous embodiment, the tire cord has a strength utilization rate of at least 88% according to the following formula 2: [Formula 2] Strength utilization rate (%) = [Tensile strength of tire cord (g / den) / Tensile strength of polyester yarn (g / den)] × 100.

[0057] The tire cord preferably has a strength utilization rate of 88.5% or more, particularly preferably 88.7% or more, and very preferably 88.9% or more. It is also desirable for the tire cord to have a strength utilization rate of 91.0% or less, particularly preferably 90.8% or less, very preferably 90.6% or less, and even more preferably 90.4% or less. As a result, the tire cord according to this disclosure can have excellent strength.

[0058] The tire cord can have a strength utilization rate of, for example, 88.5% to 91.0%, preferably 88.7% to 90.8%, particularly preferably 88.7% to 90.6%, very preferably 88.7% to 90.4%, and even more preferably 88.9% to 90.4%.

[0059] The strength utilization rate of the tire cord may be at least 90% of the strength of the thread.

[0060] In an advantageous embodiment, the polyester yarn is a polyester multifilament composed of 200 to 2000 polyester single filaments, each having a fineness of 2.5 to 3.5 den, and the polyester yarn is impregnated with an adhesive layer.

[0061] The adhesive layer can be formed, in particular, by impregnating the raw cord with a commonly known adhesive solution. An example of an adhesive solution usable with conventional tire cords is a resorcinol-formaldehyde-latex adhesive solution (RFL adhesive solution).

[0062] The adhesive layer can be present in an amount of 0.5 to 10% by weight, preferably 1 to 8% by weight, and particularly preferably 1.5 to 6% by weight of the high-strength tire cord.

[0063] In an advantageous embodiment, the polyester yarn is manufactured from a polyester composition consisting of molten PET granules. The molten PET granules contain at least 90 mol% PET. The molten PET granules have an intrinsic viscosity of at least 1.0 dl / g.

[0064] Therefore, the molten PET granules are molten polyester granules containing 90 mol% or more of PET and having an intrinsic viscosity of 1.0 dl / g or more. The molten PET granules may also contain 92 mol% or more, preferably 95 mol% or more, particularly preferably 99 mol% or more, and very preferably 100 mol% of PET.

[0065] When the molten PET granules are formed from less than 100% PET, various known additives can be added in the process of producing the polyester composition that forms the undrawn yarn. Therefore, the type of additive is not limited.

[0066] In one embodiment, the molten PET granules may have an intrinsic viscosity of 1.0 dl / g or more, preferably 1.1 dl / g to 1.9 dl / g. The molten PET granules may preferably have an intrinsic viscosity of 1.0 dl / g or more, preferably 1.1 dl / g or more. The molten PET granules may further have an intrinsic viscosity of 1.7 dl / g or less, preferably 1.6 dl / g or less, particularly preferably 1.5 dl / g or less, and most preferably 1.4 dl / g or less.

[0067] According to one embodiment of the present invention, polyester yarn can be made into PET drawn yarn by a spinning process that uses granules containing 90 mol% or more of PET.

[0068] PET drawn yarn is produced by melt-spinning PET granules to create undrawn fibers, and then drawing the undrawn fibers. PET tire cord can also be produced as a type of dip cord by further twisting PET drawn yarn together and immersing it in an adhesive solution to produce PET drawn yarn.

[0069] In one embodiment of the present invention, the PET drawn yarn further contains 90 mol% or more of PET in order to exhibit PET properties suitable for tire cords. If the PET drawn yarn contains less than 90 mol% of PET, it is difficult for the PET drawn yarn and the tire cord manufactured therefrom to exhibit desirable physical properties.

[0070] Therefore, in relation to this disclosure, the term "PET" should be understood to mean a PET content of at least 90 mol%, unless otherwise stated in this disclosure.

[0071] In a favorable embodiment, Polyester yarn has a tensile strength of 7.5-11.0 g / den and an elongation at break of 10-20%.

[0072] In a favorable embodiment, The raw cord of the tire cord has a total fineness of 1000 to 9000 denier, preferably 1000 to 6000 denier.

[0073] In advantageous embodiments, the tensile strength of the tire cord is greater than 8.2 g / den, particularly preferably greater than 8.4 g / den, and very preferably greater than 8.5 g / den. In advantageous embodiments, the tire cord also has a tensile strength of 11 g / den or less, preferably 10.0 g / den or less, according to the ASTM-D-885 standard test method. The breaking strength of the tire cord can be particularly between 8.0 g / den and 11 g / den.

[0074] In an advantageous embodiment, the tire cord comprises exactly two or exactly three polyester threads, preferably exactly two polyester threads, and these polyester threads are secondarily twisted. Thus, the tire cord has a ×2 or ×3, preferably ×2 structure.

[0075] In a favorable embodiment, The tire cord has a total fineness of 2500 den to 4500 den, preferably 3000 den to 4000 den.

[0076] In a favorable embodiment, Polyester yarn has a fineness of 1500 den to 2000 den.

[0077] It was found to be particularly advantageous when the tire cord has a structure of 1500 den x 2 or 2000 den x 2.

[0078] Raw tire cord can be manufactured by passing drawn polyester yarn through a cable cord twisting machine and performing primary and secondary twisting on the yarn at a twist count of 200 TPM to 500 TPM in each case. Impregnated tire cord can be manufactured by immersing the raw cord in an adhesive coating solution, followed by drying and heat treatment.

[0079] The pneumatic vehicle tire according to the present invention is preferably a tire for a passenger car, van, or light truck. It is preferably a radial tire.

[0080] Pneumatic vehicle tires are manufactured using methods and apparatus known to those skilled in the art.

[0081] This involves first obtaining an unvulcanized blank of an unvulcanized pneumatic vehicle tire having a carcass with tire cords as strength members, including all the embodiments described, by stacking corresponding components, including an unvulcanized rubber mixture, on top of each other. The blank is then vulcanized.

[0082] The present invention includes, in particular, all of the advantageous embodiments reflected in the patent claims. The present invention also includes configurations obtained from combinations of different features, each with a different level of preference, and therefore the present invention also includes combinations of a first feature described as "preferred" with another feature described as, for example, "particularly preferred."

[0083] The method for manufacturing tire cord according to the present invention may include the steps of: manufacturing polyester yarn by spinning molten polyester granules containing at least 90 mol% PET and having an intrinsic viscosity of 1.0 dl / g or more using a spinning package including a spinneret equipped with a nozzle unit; manufacturing raw cord using the polyester yarn; and immersing the raw cord in an adhesive solution and then heat-treating it. The step of manufacturing polyester yarn may include the step of extruding molten polyester granules through a spinneret including a nozzle unit having a shear rate of 220 to 260¹ / s and a polymer extrusion rate of 2.0 m / min or less under a spinning package pressure of 1800 to 2500 psi to form polyester single filaments having a fineness of 2.5 to 3.5 den.

[0084] In order to manufacture tire cords that achieve high tensile strength, high modulus of elasticity, low shrinkage rate, and high elongation, a low DPF of the polyester yarn is advantageous. In this disclosure, the polymer extrusion rate from the nozzle and the low DPF of the polyester can be adjusted to achieve high spinning tension and high draw.

[0085] Under the yarn manufacturing conditions, the low extrusion pressure of the nozzle may further reduce the toughness of polyester yarn and tire cord. Therefore, this disclosure is characterized by setting a high extrusion pressure within the spinning package, thereby maintaining a high shear rate at the nozzle.

[0086] Therefore, this disclosure is characterized in that, by adjusting the spinning conditions and simultaneously maintaining the spinning package pressure within a certain range, the excellent physical properties of the polyester yarn can be retained in the tire cord even after post-treatment such as twisting and heat treatment, and as a result all the physical properties of the tire cord required for weight reduction can be achieved.

[0087] Tire cord can be manufactured by conventional processes, except for adjustments to the spinning process and pressurization of the spinning package during the production of polyester yarn.

[0088] As described above, high-strength polyester yarn can be manufactured, particularly for tire cords, by spinning molten polyester granules containing at least 90 mol% PET and having an intrinsic viscosity of 1.0 dl / g or more, using a spinning package that includes a spinneret equipped with a nozzle unit.

[0089] In exemplary embodiments, the molten polyester granules may include molten PET granules containing at least 90 mol% PET and having an intrinsic viscosity of 1.0 dl / g or more, preferably 1.1 dl / g to 1.9 dl / g. The molten PET granules may preferably have an intrinsic viscosity of 1.0 dl / g or more, preferably 1.1 dl / g or more. The molten PET granules may further have an intrinsic viscosity of 1.7 dl / g or less, preferably 1.6 dl / g or less, particularly preferably 1.5 dl / g or less, and most preferably 1.4 dl / g or less.

[0090] Furthermore, the molten PET granules may contain 92 mol% or more, preferably 95 mol% or more, particularly preferably 99 mol% or more, and very preferably 100 mol% of PET. When the molten PET granules are formed from less than 100% PET, various known additives may be added in the process of producing the polyester composition that forms the undrawn yarn. Therefore, the type of additive is not limited.

[0091] Spinning can be further carried out at 270°C to 300°C, preferably 275°C to 300°C, and particularly preferably 275°C to 290°C, using a spinneret having 200 to 550 spinning openings.

[0092] The process for manufacturing polyester yarn after the process for manufacturing multiple filaments may further include heating and cooling the extruded multiple filaments, bundling the cooled filaments, then stretching the filaments to manufacture stretched polyester yarn, and then winding it up.

[0093] A method for producing polyester yarn may preferably include the steps of: producing multiple filaments by extruding molten polyester granules having an intrinsic viscosity of 1.0 dl / g or more through a spinneret including a nozzle unit having a shear rate of 220 to 260¹ / s and a polymer extrusion rate of 2.0 m / min or less under spinning package pressure of 1800 to 2500 psi; heating the extruded multiple filaments with a heating unit; cooling the heated filaments with a cooling unit; bundling the multiple filaments to form a polyester multifilament; stretching the polyester multifilament; and winding the stretched multifilament.

[0094] High-strength polyester yarn can be manufactured by a method that includes, for example, the steps of: melting PET granules containing at least 90 mol% PET and having an intrinsic viscosity of 1.0 dl / g or more, preferably 1.1 dl / g or more, and particularly preferably 1.5 dl / g or more, by adjusting spinning conditions and spinning package pressure within the above range, and extruding them into a plurality of filaments through a nozzle unit; heating the heated plurality of filaments through a heating unit arranged around the nozzle unit; cooling the heated plurality of filaments through a cooling unit; bundling the plurality of filaments to form a polyester multifilament; stretching the polyester multifilament; and winding the stretched multifilament.

[0095] In this case, the spinning package can adjust the extrusion pressure within the range of 1800 to 2500 psi (approximately 126.55 to 175.8 kgf / cm2). However, if the extrusion pressure of the spinning package is less than 1800 psi, the polymer extrusion rate at the nozzle will decrease, and the required performance may not be achieved. Conversely, if the extrusion pressure is more than 2500 psi, excessive pressure may cause equipment problems, such as leakage of the package.

[0096] When molten polyester granules are extruded from a nozzle including a nozzle unit, the shear rate in the nozzle can be further set to 220-2601 / s. If the shear rate is 2201 / s or less, the orientation of the polymer in the nozzle may decrease, potentially resulting in a decrease in the toughness of the yarn. If the shear rate is 2601 / s or more, the decrease in yarn tension may impair the dimensional stability of the yarn.

[0097] The polymer extrusion rate at the nozzle can be further reduced to 2.0 m / min or less by adjusting the shear rate at the nozzle. The polymer extrusion rate at the nozzle can be particularly 0.1 to 2.0 m / min, preferably 0.5 to 2.0 m / min, especially preferably 1.0 to 2.0 m / min, very preferably 1 to 1.9 m / min, even more preferably 1.3 to 1.9 m / min, and even more preferably 1.5 to 1.9 m / min. If the polymer extrusion rate is 2 μm / min or higher, the polymer extrusion rate at the nozzle will decrease, and the required performance may not be obtained.

[0098] This method enables the formation of polyester multifilaments containing polyester single filaments having a fineness of 2.5 to 3.5 den. In other words, this disclosure confirms that polyester multifilaments containing individual polyester filaments having a DPF of 2.5 to 3.5 are formed.

[0099] The polyester multifilament may contain 200 to 2000 polyester single filaments having a fineness of 2.5 to 3.5 den, preferably 400 to 1200 of the corresponding polyester single filaments. The fineness of the polyester single filaments is preferably 2.6 to 3.5 den, and particularly preferably 2.7 to 3.4 den.

[0100] On the other hand, the method for manufacturing polyester yarn may include heating and cooling a plurality of extruded filaments, bundling the cooled filaments, then stretching the filaments to produce stretched polyester yarn, and then winding the yarn using a conventional method.

[0101] Hereafter, the further features, advantages, and details of the present invention and the method for manufacturing tire cord will be described in detail with reference to schematic diagrams.

[0102] Figure 1 shows a polyester yarn manufacturing apparatus.

[0103] As shown in Figure 1, the polyester yarn manufacturing apparatus 1 according to the embodiment of the present disclosure comprises an extruder 10, a spinning package 20, a cooling unit 30, a bundling unit 40, a stretching unit 50, and a winding unit 60.

[0104] The upper surface of the extruder 10 may have a hopper 12 that receives the polymer granules (arrows) formed thereon. The extruder 10 may also be equipped with a heating device and a conveying device for melting the polymer granules supplied from the hopper 12 and transporting the molten granules to the spinning package 20. The polymer used may be polyester, but is not limited to polyester.

[0105] In the following description, a yarn manufacturing apparatus 1 capable of producing polyester yarn using polyester granules will be described as an example for the purpose of providing a thorough explanation. However, the yarn manufacturing apparatus according to the embodiments of this disclosure can be used not only for the production of polyester yarn but also for the production of other yarns known from the prior art.

[0106] Furthermore, the spinning package 20 extrudes molten polyester granules conveyed from the extruder to form a plurality of filaments 2. The spinning package 20 may consist of a spinning block, a package body, a spinneret, and a heating unit, but its configuration is not limited thereto.

[0107] An apparatus for producing polyester yarn includes, in particular, a spinning package including a spinneret with a nozzle unit having a plurality of extrusion openings for extruding molten granules; a heating unit positioned around the nozzle unit for heating a plurality of filaments extruded from the plurality of extrusion openings; a cooling unit for cooling the plurality of filaments heated by the heating unit; a bundling unit for bundling the plurality of filaments cooled by the cooling unit to form a multifilament; and a stretching unit for stretching the multifilament. The plurality of extrusion openings can be arranged in a circle in at least two rows. The distance between adjacent extrusion openings in any one row, the distance between adjacent extrusion openings in another row, and the distance between extrusion openings arranged close to each other in any one row and in another adjacent row.

[0108] This disclosure may provide, but is not limited to, the use of a general process for cooling the filament 2 via the cooling unit 30.

[0109] In this disclosure, a coolant, such as air, can enter the cooling chamber 32 through the coolant inlet 34 and exit through the coolant outlet 36.

[0110] High-strength polyester yarn for tire cords can be further manufactured by a process that includes a step of drawing an undrawn multifilament 4 in at least two steps, including three or more godet rollers 52, 54, 56, 58. In this case, the three or more godet rollers include first, second, and third godet rollers arranged in series based on the direction of movement of the multifilament, with the rotational speed of the first godet roller being 2000 to 4000 m / min and the rotational speed of the third godet roller being 5000 to 7000 m / min.

[0111] The process of stretching polyester multifilaments may include stretching the polyester multifilaments at a total stretch ratio of 1.0 to 3.0, and stretched polyester yarn can be produced by the above method. The total stretch ratio can preferably be 1.5 to 3.0, or 1.5 to 2.5. In other words, in order to increase the degree of orientation due to stretching and, as a result, to achieve an appropriate strength level, the total stretch ratio of the stretched polyester yarn is preferably 1.0 or higher. However, in order to prevent yarn breakage due to excessive stretching, the total stretch ratio of the stretched polyester yarn is preferably 3.0 or lower.

[0112] The multi-stage stretching speed ratio can be further defined as the ratio of the difference between the rotational speed of the first godet roller and the rotational speed of the second godet roller, and the difference between the rotational speed of the second godet roller and the rotational speed of the third godet roller, and the multi-stage stretching speed ratio can be set to 30:70 to 60:40.

[0113] The winding unit 60 generates polyester yarn 6 by winding up the multifilament stretched by the stretching unit 50.

[0114] The high-strength polyester yarn produced by the above method may have a breaking strength of 7.5 to 11.0 g / den and an elongation at break of 10 to 20%.

[0115] To manufacture raw cord, the yarn can be twisted in a first process, and the yarn can be twisted together in a second process to form a cord (raw cord) cable. This may be done in a single process using a direct cable forming device, or in two consecutive separate processes using a ring twisting machine. The twist count may be between 200 TPM and 500 TPM.

[0116] Furthermore, the step of immersing the raw cord in an adhesive solution and then heat-treating the thread may also be a step of manufacturing tire cord (impregnated cord) by immersing the raw cord in an adhesive solution and then performing heat treatment.

[0117] The adhesive layer can be formed, in particular, by impregnating the raw cord with a commonly known adhesive solution. An example of an adhesive solution usable with conventional tire cords may be a resorcinol-formaldehyde-latex adhesive solution (RFL adhesive solution).

[0118] After impregnation with the adhesive solution, a heat treatment step can be carried out. The heat treatment step can be performed at a temperature of 220°C to 260°C for 90 to 360 seconds, preferably at a temperature of 230°C to 250°C for 90 to 240 seconds, and more preferably at a temperature of 240°C to 245°C for 90 to 120 seconds.

[0119] By immersing high-strength polyester yarn in an adhesive solution and heat-treating the yarn under these conditions, the dimensional stability of the tire cord can be further improved, and changes in the physical properties of the tire during vulcanization can be further reduced.

[0120] The present disclosure will be described in more detail below with reference to examples and comparative examples. The following examples and comparative examples are provided solely for the purpose of making the present invention easier to understand and are not intended to limit the scope of the present invention.

[0121] Hereafter, further features, advantages, and details of the present invention and the method for manufacturing tire cord will be described in more detail with reference to embodiments and reference examples that may represent the embodiments. [Examples]

[0122] [Examples and Reference Examples: Manufacturing of Polyester Yarn] <Example 1> In Example 1, a polyester yarn 6 was produced using the yarn manufacturing apparatus 1 shown in Figure 1, which contains at least 90 mol% PET and has a single filament fineness of 2.7 to 3.4 for polyester single filaments and a total fineness of 1500.

[0123] Specifically, PET granules containing at least 90 mol% PET and having an intrinsic viscosity (IV) of 1.0 to 1.4 dl / g were melted using a single-screw extruder to produce molten polyester granules. Then, as shown in Table 1, the molten polyester granules were spun at a spinning speed of 3200 m / min using a 170 spindle nozzle (L / D = 4.0 / 1.0, extrusion aperture: 500) to produce multiple filaments 2.

[0124] At this time, the manufacturing conditions for multiple filaments, including the extrusion rate of the spinneret, were adjusted as shown in Table 2 (DPF, polymer extrusion rate at the nozzle, shear rate at the nozzle, spinning package pressure).

[0125] Subsequently, multiple filaments 2 were heated in a heating unit, then cooled in a cooling unit 30, and the cooled filaments were bundled together to produce undrawn multifilament 4 (undrawn yarn).

[0126] The molten material for spinning was extruded from the spinneret to obtain a drawn polyester yarn with a total fineness of 1000 den (single fineness of approximately 4 den / filament). The process for obtaining the drawn polyester yarn was carried out at a spinning temperature of 290°C, a spinning speed of 3200 m / min, a total draw ratio of 1.5, and a relaxation rate of 1.5% (heat treatment at 180°C after drawing).

[0127] Polyester yarn (drawn yarn) was manufactured by winding up drawn multifilament.

[0128] <Reference example 1> Polyester yarn was produced in the same manner as in Example 1, except that the spinneret diameter, aperture number, spinning conditions, and spinning package pressure were changed as shown in Tables 1 and 2 below.

[0129] [Table 1]

[0130] [Table 2]

[0131] [Example 2 and Reference Example 2: Manufacturing of Tire Cord] The tire cords in Example 2 and Reference Example 2 were manufactured using the polyester yarn produced in Example 1 and Reference Example 1, respectively, under the same conditions.

[0132] Specifically, polyester yarn was passed through a twisting machine to produce two strands of primary twisted yarn (Z direction) with a twist count of 460 TPM. Then, these two primary twisted yarns were subjected to secondary twisting (S direction) with a twist count of 460 TPM to produce a raw cord. The raw cord thus produced was immersed in an adhesive solution containing resorcinol formaldehyde dendroxycellulose (RFL), then dried at 150°C for 100 seconds, and heat-treated at 240°C for 100 seconds to form a tire cord (impregnated cord). The tension applied to the raw cord during the immersion, drying, and heat-treatment processes was 0.5 kg / cord.

[0133] Furthermore, the raw cord showed a total fineness of 1000 to 6000 denier.

[0134] [Experimental Example A: Evaluation of the physical properties of polyester yarn and tire cord] The tensile strength and elongation at break of the polyester yarn manufactured as described above and the tire cord made from this polyester yarn were measured.

[0135] Tensile strength, elongation at break, and elongation According to the ASTM-D-885 standard test method, the tensile strength (g / den), elongation, and strength ratio of drawn polyester yarn and tire cord were tested using a universal tester according to Equation 2. The results are shown in Tables 3 and 4 below. The sample length was 250 mm, the tensile speed was 300 mm / min, and the initial load was set to 0.05 g / den. In the stress-strain curve obtained from the above test, the elongation was determined under a load of 4.5 g / den.

[0136] [Table 3]

[0137] [Table 4]

[0138] With respect to Tables 3 and 4, the polyester yarn of Example 1 and the tire cord of Example 2 exhibit improved and reported superior physical properties compared to their respective reference examples.

[0139] [Experimental Example B: Evaluation of the physical properties of tire cords] The tensile strength, elastic modulus, toughness, and SWI physical properties of the tire cords manufactured in the examples and reference examples were measured. The results are shown in Table 5 below.

[0140] (1) Tensile strength and toughness The tensile strength (g / den), elongation (%), and toughness of the tire cord were determined using a universal testing machine according to the ASTM-D-885 standard test procedure. The sample length was 250 mm (cord length: 600 mm), the tensile speed was 300 mm / min, and the initial load was set to 0.05 g / den.

[0141] (2) Elastic modulus (LASE@2%, LASE@5%) Stress-strain curves were obtained according to the ASTM-D885 standard test method. Using these stress-strain curves, the loads at longitudinal elongations of 2% and 5% were determined, and the LASE@5% during elongation was measured. Samples were stored for 24 hours in an atmosphere of 20°C and 65% relative humidity before measurement.

[0142] (3) SWI SWI was determined by Formula 1 in accordance with claim 1. Furthermore, (A) can be 1.0% to 3.2%, (B) can be 0.7% to 2.8%, (C) can be 1.3% to 1.7%, and (D) can be 4.2% to 4.6%.

[0143] Specifically, a 250 mm sample with a total fineness of 1000 to 6000 den was stored at 25°C and 65% relative humidity for 24 hours, and then its length (L0) was measured under an initial tensile load of 0.01 g / den. Subsequently, it was treated for 2 minutes at 180°C under an initial tensile load of 0.01 g / den using a shrinkage tester, and then the length of the sample (L1) was measured. L0 and L1 were each measured three times. The rate of change in the sample length {=[(L0-L1) / L0]×100} was defined as the shrinkage rate DL1 before cooling.

[0144] Furthermore, the residual shrinkage of the sample was measured using a shrinkage tester, and then the sample was removed from the oven under a constant load and cooled at room temperature (25°C) for approximately 1 minute. After that, the residual shrinkage rate was measured once the cord had stabilized. Therefore, the residual shrinkage rate after cooling represents the residual shrinkage rate of ΔL2 ({=[(L1-L3) / L1]×100}), and the length (L3) was measured 1 minute after cooling.

[0145] [Table 5]

[0146] Regarding Table 5, the tire cord of Example 2 has a tensile strength of 8.0 g / den or more, a LASE@2% of 1.1 g / den or more, a LASE@5% of 2.5 g / den or less, and a toughness of 183 (g / den)·mm or more, as determined according to the ASTM-D-885 standard test method in each case, and also achieves an SWI value of 3.6% or less. This means that the tire cord of Example 2 has the effect of high modulus of elasticity, low shrinkage rate, and high elongation, i.e., the tire cord maintains excellent strength even after the post-processing of the yarn. This is clearly an advantageous characteristic compared to Reference Example 2.

[0147] In Reference Example 2, the elongation ratio was less than the range of the present invention as disclosed, the DPF was 3.9 or higher, and the toughness value was 175.0 (g / den) mm or lower. Furthermore, in Reference Example 2, the LASE@2% value was 1.0%, which was lower than that of Example 2, and therefore the improvement in elastic modulus was limited.

[0148] Therefore, when manufacturing yarn for obtaining tire cord, it is necessary to adjust the pressure of the spinning package while using a spinning process for high-count multifilaments with specific spinning conditions in order to ensure excellent physical properties, especially toughness.

[0149] Ply strength is defined with respect to the arrangement density of each reinforcing member in a carcass ply of 180 epdm ("ends per dm"). The ply strength of the corresponding carcass ply containing the tire cord in Example 2 is greater than that of the corresponding carcass ply containing the cord in Reference Example 2. Ply strength can be determined by multiplying the tensile strength of the tire cord according to the ASTM-D-885 standard test by the arrangement density of the tire cord in the ply and normalizing by the fineness of the tire cord.

[0150] [Tire Implementation Example: Evaluation of Rolling Resistance] We manufactured and tested pneumatic vehicle tires for vans. These tires differ only in the type and arrangement density of the carcass ply strength members. The arrangement density is selected so that the distance between cords in the carcass ply of the two tires is approximately the same. The carcass strength members consist of exactly two polyester threads that are double-twisted, so the tire cords have a ×2 structure.

[0151] The carcass strength member of the reference tire has a 2000 den × 2 structure. The polyester yarn is a conventional PET multifilament yarn with a fineness of 2000 den. The carcass strength member of the reference tire is arranged in the carcass ply at a placement density of 105 epdm.

[0152] Example tire 1 is in accordance with the present invention, and its carcass ply includes the tire cord according to the present invention as a carcass strength member. The tire cord of the present invention has a 1500 denier × 2 structure and is arranged in the carcass ply at a placement density of 118 epdm. The tire cord of the example tire may be the cord according to Example 2.

[0153] [Table 6]

[0154] Table 6 shows the physical properties of the tire carcass cords and the ply strength of each carcass ply.

[0155] These characteristics are also normalized based on diameter (mm) and / or ply density (epdm). Reducing the diameter and the resulting reduction in ply thickness are key to improving rolling resistance. The ply density is selected so that the distance between cords in the carcass plies of the two tires is similar.

[0156] The tire cord of the present invention in the example tire achieves remarkably high tensile strength per cord and remarkably high ply strength, which in turn makes it possible to reduce the core diameter and improve rolling resistance (see Table 7).

[0157] Tire tests conducted using these tires revealed that the durability and high-speed characteristics of the compared tires were at approximately the same level. The fineness of the carcass strength components in the example tire was reduced compared to the reference example tire.

[0158] Table 7 clearly shows that the rolling resistance of the example tires was advantageously improved by 1.5% compared to the reference example tires of each example. Values ​​greater than 100% correspond to lower, i.e., improved, rolling resistance (RR).

[0159] [Table 7]

[0160] While preferred embodiments of the present disclosure have been described above, the present disclosure is not limited thereto. Embodiments of the present invention include all kinds of modifications and recognized equivalents thereof that can be readily performed by those skilled in the art of the present disclosure. [Explanation of Symbols]

[0161] 1. Polyester yarn manufacturing apparatus 2 filaments 4 Unstretched multifilaments 6. Polyester yarn 10 Extruder 12 hoppers 20 spinning packages 30 Cooling Units 32 Cooling Chambers 34 Coolant Inlet 36 Coolant outlet 40 Focusing Units 50 Extension Units 52, 54, 56, 58 Godet Roller 60 winding units

Claims

1. A pneumatic vehicle tire comprising a carcass extending from one bead region to the other and fixed thereto by a high-tensile bead core being wrapped around it, wherein the carcass includes at least one carcass ply having parallel and spaced-apart strength members embedded in an elastomer material, the strength members being in the form of tire cords comprising at least one polyester yarn (6) containing at least 90 mol% polyethylene terephthalate (PET) in each case, The aforementioned tire code is determined in each case according to the ASTM-D-885 standard test method. - Tensile strength of at least 8.0 g / den, - At least 1.1 g / den of LASE @ 2%, - Maximum 2.5g / den of LASE@5%, • Toughness of at least 183 (g / den)·mm, - And a sidewall indentation (SWI) value of 5% or less, preferably 4% or less, and particularly preferably 3.6% or less. It has, The aforementioned sidewall indentation SWI is given by the following equation 1: [Formula 1] SWI (%) = [(D) - (C)] + [(A) - (B)] Given by, in equation 1: (A) is the residual shrinkage rate of the tire cord, measured after the thermal shrinkage rate is measured using a shrinkage tester (sample length 250 mm, 180°C, exposure time 2 minutes, initial load 20-45 g), followed by cooling for 1 minute. (B) is the residual shrinkage rate of the tire cord, measured after the thermal shrinkage rate is measured using a shrinkage tester (sample length 250 mm, 180°C, exposure time 2 minutes, initial load 40-90 g), followed by cooling for 1 minute. (C) is the elongation of the tire cord under a load of 1.5 to 3.0 kg, as measured according to the ASTM-D-885 standard test method. (D) is the elongation of the tire cord under a load of 3.0 to 6.0 kg, as measured according to the ASTM-D-885 standard test method. A pneumatic vehicle tire characterized by the following features.

2. The pneumatic vehicle tire according to claim 1, wherein the tire cord has a thermal shrinkage rate of less than 4%, preferably less than 3%, and particularly preferably less than 2.5%, as measured according to the ASTM-D-885 standard test method.

3. A pneumatic vehicle tire according to claim 1 or 2, characterized in that (A) is 1.0% to 3.2%, (B) is 0.7% to 2.8%, (C) is 1.3% to 1.7%, and (D) is 4.2% to 4.6%.

4. The pneumatic vehicle tire according to any one of claims 1 to 3, characterized in that the carcass ply has a ply strength of at least 0.94 kg / dm / den.

5. The aforementioned tire cord is given by the following equation 2: [Formula 2] Strength utilization rate (%) = [Tensile strength of tire cord (g / den) / Tensile strength of polyester yarn (g / den)] × 100 A pneumatic vehicle tire according to any one of claims 1 to 4, characterized in having a strength utilization rate of at least 88%.

6. The polyester yarn (6) is a polyester multifilament composed of 200 to 2000 polyester single filaments, each having a fineness of 2.5 to 3.5 den. The polyester yarn is impregnated with an adhesive layer. A pneumatic vehicle tire according to any one of claims 1 to 5, characterized in that

7. The pneumatic vehicle tire according to any one of claims 1 to 6, characterized in that the polyester yarn (6) is manufactured from a polyester composition composed of molten PET granules, the molten PET granules contain at least 90 mol% PET, and the molten PET granules have an intrinsic viscosity of at least 1.0 dl / g.

8. The pneumatic vehicle tire according to any one of claims 1 to 7, characterized in that the polyester yarn (6) has a tensile strength of 7.5 to 11.0 g / den and an elongation at break of 10 to 20%.

9. The pneumatic vehicle tire according to any one of claims 1 to 8, characterized in that the raw cord of the tire cord has a total fineness of 1,000 to 9,000 denier (den), preferably 1,000 to 6,000 den.

10. The pneumatic vehicle tire according to any one of claims 1 to 9, characterized in that the tensile strength of the tire cord is greater than 8.2 g / den, more preferably greater than 8.4 g / den, and more preferably greater than 8.5 g / den.

11. The pneumatic vehicle tire according to any one of claims 1 to 10, characterized in that the tire cord contains exactly two or exactly three, preferably exactly two, polyester yarns, and the polyester yarns are secondarily twisted.

12. The pneumatic vehicle tire according to any one of claims 1 to 11, characterized in that the tire cord has a total fineness of 2500 den to 4500 den, preferably 3000 den to 4000 den.

13. The pneumatic vehicle tire according to any one of claims 1 to 12, characterized in that the polyester yarn (6) has a fineness of 1500 den to 2000 den.

Images