WO2022231286A1 - Cord comprising bio-based component and method for preparing same - Google Patents

Abstract

The present application relates to a hybrid cord comprising a bio-based nylon primarily-twisted yarn. According to the present application, provided is a hybrid cord which comprises a bio-based nylon primarily-twisted yarn having a higher modulus than chemically synthesized nylon, while also having elongation and fatigue resistance properties equivalent to or higher than a commercially required standard (that is, the standard of a cord comprising conventional chemically synthesized nylon primarily-twisted yarn).

Description

Code containing bio-derived ingredients and manufacturing method thereof

Cross-Citation with Related Technology(s)

This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0056810 dated April 30, 2021 and Korean Patent Application No. 10-2022-0051246 dated April 26, 2022, All content disclosed in the literature of the application is incorporated as a part of this specification.

technical field

The present application relates to a code containing a bio-derived component and a method for manufacturing the same. Specifically, the present application relates to a first lower twisted yarn formed by giving a twist to a bio-nylon fiber; And it relates to a hybrid cord comprising a second lower twisted yarn formed by imparting twist to a different type of resin fiber different from the bio-nylon, and a method for manufacturing the same.

A cord used as a rubber reinforcing material for an automobile tire must satisfy physical properties capable of maintaining the stability and durability of the tire in consideration of the specific driving conditions of the tire. For example, a tire cord must have excellent balance between physical properties such as strength, medium elongation, cut elongation, and dry heat shrinkage, and in addition, it must be able to provide excellent fatigue resistance. In particular, since tire reinforcement materials are subjected to relatively high loads in an environment where repeated tension and compression are given, high modulus (ie, relatively low elongation) cords are used in such a fatigue environment as above. retention will decrease. Considering such fatigue resistance characteristics, on the premise that the basic physical properties required for tire application are satisfied, having a modulus value as low as possible helps to improve the fatigue resistance performance of the cord, and consequently improves the durability of the tire can be found to help.

A cord for a tire reinforcement material may be made by twisting a component called a lower-twisted yarn, and the filament or fiber component included in the lower-twisted yarn may be selected in consideration of performance required for the use of the tire reinforcement material. For example, aramid fiber has a high modulus, and since the amount of change in modulus at room temperature and high temperature is small, it has an advantage in suppressing the flat spot phenomenon in which the tire is deformed when parked for a long time, so it was mainly used for high-quality tires. However, aramid fibers are expensive and have poor fatigue resistance due to their high modulus properties. That is, in the case of a tire cord containing aramid lower-twisted yarn, while the reinforcing properties are excellent, fatigue resistance performance or durability is not good. Accordingly, a lower-twisted yarn containing nylon or polyester (eg, PET), which has a relatively low modulus compared to aramid and is advantageous for securing fatigue resistance performance, is used together with the aramid lower-twisted yarn.

On the other hand, in the case of the lower-twisted yarn or filament used for manufacturing the cord, it is common that chemically or artificially synthesized (chemical-based or artificial product) is used. However, for chemical-based or artificial materials, supply may be disrupted if the supply of raw materials is unstable. And, with respect to the use of chemically artificially synthesized materials, it has been pointed out that environmental pollution is greatly induced not only in the process of obtaining raw materials but also in the process of manufacturing products (or materials).

Therefore, it is necessary to develop a code that is not significantly affected by the problem of supply and demand of synthetic raw materials, is environmentally friendly, and can provide physical properties equivalent to or higher than that of a conventional cord manufactured from chemical synthetic fibers.

An object of the present application is to provide an eco-friendly cord (cord) including a bio-based nylon fiber and a method for manufacturing the same.

Another object of the present application is to provide a cord and a manufacturing method thereof that are not significantly affected by the problem of supply and demand of synthetic raw materials, since they contain bio-derived fibers.

Another object of the present application is to provide a cord capable of providing physical properties equivalent to or higher than that of a conventional cord including only chemically synthesized fibers and a method for manufacturing the same.

The above and other objects of the present application can all be solved by the present invention described in detail below.

According to an embodiment of the present application, a cord comprising a lower twisted yarn that is a different heterogeneous fiber component, one of the heterogeneous fiber components is bio-derived nylon (or bio-based nylon), and a manufacturing method thereof are provided.

Although the hybrid cord of the present application uses bio-derived nylon, in properties such as strength, medium elongation, elongation at cut, dry heat shrinkage, adhesion, and/or fatigue resistance, physical properties at a commercially required level (that is, conventional chemical The level of physical properties of cords including synthetic nylon lower-twisted yarns) can be provided.

Specifically, the inventors of the present application have found that when bio-nylon fibers are replaced with chemical synthetic nylon fibers used in the production of hybrid tire cords, bio-nylon fibers have high modulus properties (that is, low and medium elongation) was confirmed. When the initial modulus on the stress-strain curve pattern is high, the force received during tension and compression is increased, and the fatigue resistance property is deteriorated. Chemically synthesized nylon fibers have a lower modulus than other materials, so they have an advantageous function in securing the fatigue resistance of cords and tires in a situation where tension and compression are repeated. When nylon is substituted, it is disadvantageous for the hybrid cord to secure the fatigue resistance property due to the increase in the modulus of the nylon lower-twisted yarn. Accordingly, the inventor of the present application solves the problem of supply and demand of synthetic materials and the resulting price fluctuation, is eco-friendly, and hybrid cord that can provide physical properties equivalent to or higher than that of the conventional hybrid cord (including chemically synthesized nylon lower-twisted yarn) The invention of the present application was completed.

As used herein, "bio-derived nylon or bio-nylon" may mean that a component used to manufacture nylon is derived from natural resources, for example, vegetable resources. For example, the bio-based nylon may be or include PA56 or nylon 56. Although not particularly limited, the bio-derived nylon is, for example, 'pentamethylenediamine ( pentamethylenediamine)' may be formed by reacting with dicarboxylic acid.

Although not particularly limited, to determine whether it is a bio-derived nylon lower-twisted yarn, (radioactive) carbon dating can be made. In the case of bio-nylon derived from bio-mass such as glucose or lysine, the half-life of the isotope is different from that of chemically synthesized nylon. This measurement method is standardized by countries or organizations around the world (eg, ASTM (American Society for Testing and Materials), CEN (European Standards Commission), etc. For example, ASTM-D6866 method may be considered.

In the present specification, "cord" may refer to a hybrid cord including at least two different heterogeneous fibers. For example, the cord may refer to a hybrid cord including at least two or more lower twisted yarns including different types of fibers. More specifically, the hybrid cord may mean that a coating agent such as an adhesive is coated on a fiber component (ply-twisted yarn), that is, a dip cord. Alternatively, a cord including at least two heterogeneous fibers in a state in which the coating agent is not coated on the fiber component may be referred to as a raw cord. The cord or the raw cord has a ply-twisted yarn structure in which at least a first lower twisted yarn and a second twisted yarn are twisted together (that is, the lower twisted yarns are twisted).

As used herein, "lower twist" means twisting a thread or a filament in one direction, and "lower twisting yarn" means a single ply yarn made by twisting a thread or filament in one direction, that is, a single yarn. ) can mean Although not particularly limited, the lower edge may mean, for example, a clockwise or counterclockwise twist.

Also, in the present specification, "plied yarn" may mean a yarn made by twisting two or more lower twisted yarns together in one direction. The upper edge may mean a twist in the opposite direction to the twist in which the lower edge is formed. For example, the sangyeon may mean twisting in a counterclockwise or clockwise direction.

The lower-twisted yarn or the ply-twisted yarn produced by applying twist in any direction may have a predetermined number of twists. In this case, "the number of twists" means the number of twists per 1 m, and the unit may be TPM (Twist Per Meter).

Hereinafter, the hybrid code of the present application and a manufacturing method thereof will be described in more detail.

In an example related to the present application, the present application relates to an eco-friendly cord comprising a bio-based fiber. The bio-derived fiber included in the cord may be referred to as a bio-based nylon fiber or a bio nylon fiber, and is included in the lower twisted yarn constituting the cord.

Bio-nylon has different properties from chemically synthesized nylon. For example, as confirmed in an experiment to be described later (see Table 1), bio-nylon has a higher modulus than chemically synthesized nylon. Specifically, referring to Table 1, when chemically synthesized PA66 and bio-nylon PA56 have a fineness in the range of 700 to 1500 denier in common (Table 1, about 845 denier), the intermediate elongation of the bio-nylon yarn is low. that is confirmed For example, within the fineness range described below, the bio-nylon yarn has a median elongation (4.7 constant load elongation of cN/dtex) measured according to ASTM D885 of 15% or less, 14% or less, or 13% or less, 12% or less, 11 % or less, 10% or less, or 9% or less. The lower limit of the intermediate elongation may be 5% or more, 6% or more, 7% or more, 8% or more, 9% or more, or 10% or more.

As such, when compared to using a chemically synthesized lower-twisted nylon yarn, using a bio-nylon lower-twisted yarn having a relatively high modulus (low intermediate elongation) is disadvantageous in securing tire fatigue resistance. While using bio-nylon lower-twisted yarn, it is required to have the following code configuration in order to secure a level of fatigue resistance equivalent to or higher than that of the prior art using a chemically synthetic lower-twisted yarn having a relatively low modulus.

Specifically, the cord is a hybrid raw cord (hybrid raw cord); and a coating layer formed on the hybrid raw cord. In addition, the hybrid raw cord includes: a first lower twisted yarn formed by twisting bio-nylon fibers having a fineness of 600 to 2000 denier; and a second lower twisted yarn formed by applying twist to a heterogeneous resin fiber different from bio-nylon having a fineness of 800 to 2200 denier, wherein the number of twists of the first lower twisted yarn is in the range of 250 to 600 TPM, and the entire hybrid raw cord It includes 20 to 50% by weight of the first lower twisted yarn relative to 100% by weight. The hybrid cord provided according to the present application satisfies a strong retention rate of 90% or more after an 8-hour disk fatigue test conducted according to the JIS-L 1017 method of the Japanese Standard Association (JSA).

The cord that reinforces the performance of the tire shows different characteristics (physical properties) according to the thickness. If the thickness of the cord is thick, the performance of the tire is improved in terms of strength and modulus, but the weight increases because the thickness of the rubber covered above and below the fabric becomes thicker and the size of the tire increases. Therefore, it is unsuitable for a tire where fuel efficiency and weight reduction are important. In addition, when the thickness of the cord is thin, it is advantageous for reducing the weight of the tire, but since the strength and modulus are low, the performance as a reinforcing material cannot be sufficiently exhibited. In the present application, in consideration of this point, the fineness of the fibers forming the cord (each fiber forming the lower twisted yarn) is appropriately adjusted.

For example, the bio-derived nylon lower-twist yarn may include bio-derived nylon fibers (filaments) having a fineness of 600 to 2000 denier (de). For example, the lower limit of the fineness of the bio-derived nylon fiber is 650 denier or more, 700 denier or more, 750 denier or more, 800 denier or more, 850 denier or more, 900 denier or more, 950 denier or more, 1000 denier or more, 1050 denier or more, 1100 or more. denier or more, 1150 denier or more, 1200 denier or more, 1250 denier or more, 1300 denier or more, 1350 denier or more, or 1400 denier or more. And, the upper limit is, for example, 1950 denier or less, 1900 denier or less, 1850 denier or less, 1800 denier or less, 1750 denier or less, 1700 denier or less, 1650 denier or less, 1600 denier or less, 1550 denier or less, 1500 denier or less, 1450 denier or less. Denier or less, 1400 denier or less, 1350 denier or less, 1300 denier or less, 1250 denier or less, 1200 denier or less, 1150 denier or less, 1100 denier or less, 1050 denier or less, 1000 denier or less, 950 denier or less, 900 denier or less, 850 denier or less , 800 denier or less, 750 denier or less, or 700 denier or less.

In one example, the second lower twisted yarn may include fibers (filaments) having a fineness of 800 to 2200 denier. For example, the lower fineness limit of the fiber used to form the second lower twisted yarn is 850 denier or more, 900 denier or more, 950 denier or more, 1000 denier or more, 1050 denier or more, 1100 denier or more, 1150 denier or more, 1200 denier or more. , over 1250 denier, over 1300 denier, over 1350 denier, over 1400 denier, over 1450 denier, over 1500 denier, over 1550 denier, over 1600 denier, over 1650 denier, over 1700 denier, over 1750 denier, over 1800 denier, 1850 denier or greater, 1900 denier or greater, 1950 denier or greater, 2000 denier or greater, 2050 denier or greater, or 2100 denier or greater. And, the upper limit is, for example, 2150 denier or less, 2100 denier or less, 2050 denier or less, 2000 denier or less, 1950 denier or less, 1900 denier or less, 1850 denier or less, 1800 denier or less, 1750 denier or less, 1700 denier or less, 1650 denier or less. Denier or less, 1600 denier or less, 1550 denier or less, 1500 denier or less, 1450 denier or less, 1400 denier or less, 1350 denier or less, 1300 denier or less, 1250 denier or less, 1200 denier or less, 1150 denier or less, 1100 denier or less, 1050 denier or less , 1000 denier or less, 950 denier or less, or 900 denier or less.

In an embodiment of the present application, the hybrid raw cord includes: a first lower twisted yarn formed by applying twist to a bio-nylon fiber having a fineness of 700 to 1500 denier; and a second lower twisted yarn formed by imparting twist to a heterogeneous resin fiber different from bio-nylon having a fineness of 900 to 1800 denier.

When the number of twists of each fiber forming the lower twisted yarn is controlled within the above range, it is advantageous in securing performance (strength and modulus) as a commercially required reinforcing material in addition to reducing the weight of the tire.

The degree of twist between the lower twist yarns and/or the twist between the lower twist yarns affects the physical properties of the cord. Specifically, when the twist number of the lower twisted yarn is too low, the strength may be increased, but the strength retention of the cord is decreased due to the characteristics of the tire in which tension and compression are repeated. That is, the lower the number of twists, the lower the strength retention rate after fatigue. On the other hand, when the twist number of the lower twisted yarn is high, the modulus of the cord is lowered and the elongation is higher, so that the strength retention rate after fatigue due to tension/compression may be increased. However, when the number of twists is too high, the external force applied to the nylon cord by twisting increases, and the strength decreases compared to the low number of twists. In the present application, in consideration of the above points, the number of twists of each lower twisted yarn and the number of twists between the lower twisted yarns may be adjusted.

Specifically, the number of twists (the number of first twists) of the first lower twisted yarn including the bio-nylon may be 250 to 600 TPM. More specifically, the number of twists of the bio-derived nylon lower twist yarn is 260 TPM or more, 270 TPM or more, 280 TPM or more, 290 TPM or more, 300 TPM or more, 310 TPM or more, 320 TPM or more, 330 TPM or more, 340 TPM or more, 350 TPM or higher, 360 TPM or higher, 370 TPM or higher, 380 TPM or higher, 390 TPM or higher, 400 TPM or higher, 410 TPM or higher, 420 TPM or higher, 430 TPM or higher, 440 TPM or higher, 450 TPM or higher, 460 TPM or higher, 470 TPM or higher , 480 TPM or higher, 490 TPM or higher, 500 TPM or higher, 510 TPM or higher, 520 TPM or higher, 530 TPM or higher, 540 TPM or higher, 550 TPM or higher, 560 TPM or higher, 570 TPM or higher, 580 TPM or higher, or 590 TPM or higher . And, the upper limit of the number of twists is, for example, 590 TPM or less, 580 TPM or less, 570 TPM or less, 560 TPM or less, 550 TPM or less, 540 TPM or less, 530 TPM or less, 520 TPM or less, 510 TPM or less, 500 TPM or less. or less, 490 TPM or less, 480 TPM or less, 470 TPM or less, 460 TPM or less, 450 TPM or less, 440 TPM or less, 430 TPM or less, 420 TPM or less, 410 TPM or less, 400 TPM or less, 390 TPM or less, 380 TPM or less, 370 TPM or lower, 360 TPM or lower, 350 TPM or lower, 340 TPM or lower, 330 TPM or lower, 320 TPM or lower, 310 TPM or lower, 300 TPM or lower, 290 TPM or lower, 280 TPM or lower, 270 TPM or lower, or 260 TPM or lower.

The number of twists of the second lower twisted yarn may be appropriately adjusted in consideration of the physical properties of the cord generated through the ply twisting of the first lower twisted yarn (formed from bio-derived nylon fibers and having the same number of twists as described above).

In one example, the number of twists of the second lower twisted yarn may be in the range of 250 to 600 TPM. Specifically, the number of twists (second twist count) given to the heterogeneous resin fiber different from bio-nylon for forming the second lower twist yarn is 260 TPM or more, 270 TPM or more, 280 TPM or more, 290 TPM or more, 300 TPM or more, 310 TPM or higher, 320 TPM or higher, 330 TPM or higher, 340 TPM or higher, 350 TPM or higher, 360 TPM or higher, 370 TPM or higher, 380 TPM or higher, 390 TPM or higher, 400 TPM or higher, 410 TPM or higher, 420 TPM or higher, 430 TPM or higher , 440 TPM or higher, 450 TPM or higher, 460 TPM or higher, 470 TPM or higher, 480 TPM or higher, 490 TPM or higher, 500 TPM or higher, 510 TPM or higher, 520 TPM or higher, 530 TPM or higher, 540 TPM or higher, 550 TPM or higher, 560 TPM or higher, 570 TPM or higher, 580 TPM or higher, or 590 TPM or higher. And, the upper limit of the number of twists is, for example, 590 TPM or less, 580 TPM or less, 570 TPM or less, 560 TPM or less, 550 TPM or less, 540 TPM or less, 530 TPM or less, 520 TPM or less, 510 TPM or less, 500 TPM or less. or less, 490 TPM or less, 480 TPM or less, 470 TPM or less, 460 TPM or less, 450 TPM or less, 440 TPM or less, 430 TPM or less, 420 TPM or less, 410 TPM or less, 400 TPM or less, 390 TPM or less, 380 TPM or less, 370 TPM or lower, 360 TPM or lower, 350 TPM or lower, 340 TPM or lower, 330 TPM or lower, 320 TPM or lower, 310 TPM or lower, 300 TPM or lower, 290 TPM or lower, 280 TPM or lower, 270 TPM or lower, or 260 TPM or lower.

In one example, the number of twists (first twist number) of the bio-nylon lower twisted yarn and the second twist count (second twist count) of the lower twisted yarn may be the same or different. For the provision of the number of twists as described above, for example, a CC twisting machine (Cable cord twist machine) or a ring twisting machine (Ring-Twister) may be used. This means that the number settings are the same. However, depending on the equipment or process conditions (eg, annealing in the drying stage after immersion in an adhesive solution), a difference in the number of twists may occur within about 15%, within 10%, or within 5% of the set value.

In one example, the hybrid raw cord may be formed by twisting the first lower twisted yarn and the second lower twisted yarn within a range of 250 to 600 TPM. For example, when the aforementioned first and second lower twist yarns are staged together, the number of twists (third twist count) is 260 TPM or more, 270 TPM or more, 280 TPM or more, 290 TPM or more, 300 TPM or more, 310 TPM or higher, 320 TPM or higher, 330 TPM or higher, 340 TPM or higher, 350 TPM or higher, 360 TPM or higher, 370 TPM or higher, 380 TPM or higher, 390 TPM or higher, 400 TPM or higher, 410 TPM or higher, 420 TPM or higher, 430 TPM or higher , 440 TPM or higher, 450 TPM or higher, 460 TPM or higher, 470 TPM or higher, 480 TPM or higher, 490 TPM or higher, 500 TPM or higher, 510 TPM or higher, 520 TPM or higher, 530 TPM or higher, 540 TPM or higher, 550 TPM or higher, 560 TPM or higher, 570 TPM or higher, 580 TPM or higher, or 590 TPM or higher. And, the upper limit of the number of twists is, for example, 590 TPM or less, 580 TPM or less, 570 TPM or less, 560 TPM or less, 550 TPM or less, 540 TPM or less, 530 TPM or less, 520 TPM or less, 510 TPM or less, 500 TPM or less. or less, 490 TPM or less, 480 TPM or less, 470 TPM or less, 460 TPM or less, 450 TPM or less, 440 TPM or less, 430 TPM or less, 420 TPM or less, 410 TPM or less, 400 TPM or less, 390 TPM or less, 380 TPM or less, 370 TPM or lower, 360 TPM or lower, 350 TPM or lower, 340 TPM or lower, 330 TPM or lower, 320 TPM or lower, 310 TPM or lower, 300 TPM or lower, 290 TPM or lower, 280 TPM or lower, 270 TPM or lower, or 260 TPM or lower.

In one example, the number of twists of the first and second lower twisted yarns (ie, the number of twists at the lower twist) and the number of twists at the upper twist may be the same or different. In an embodiment of the present application, the number of twists at the time of the lower twist and the number of twists at the time of the upper twist may be set to be the same. However, in some cases, the number of twists at the time of lower twisting and the number of twists at the time of upper twisting may be slightly different in the final product. Specifically, in the case of a CC twisting machine (Cable Cord Twist machine) used in cord manufacturing, it is driven by one motor. The yarn in the creel passes through the disk connected to the motor and is connected to the regulator (the section where the lower and lower yarns meet and form the upper line), and the yarn in the port passes through the tension control guide roll. is connected to the regulator. At this time, by the rotation of the motor, the regulator to which the yarn from the disk is connected is also rotated. As a result of this mechanical movement, the lower twist is applied to the creel part yarn and the port part yarn connected by the rotation of the motor, and the lower twist yarn is twisted in the regulator to form the upper twist. As such, the raw cord is manufactured while twisting occurs due to the rotational motion of the motor. Even when the same number of twists is given (set) between the lower and upper edges, the number of twists between the upper and lower edges is may be different.

When the number of twists of the lower twisted yarn and/or the number of twists between the lower twisted yarns is controlled within the above ranges, the level commercially required with respect to properties such as strength, medium elongation, cut elongation, dry heat shrinkage, adhesion, and/or fatigue resistance. It may be advantageous in securing the physical properties of (that is, the level of physical properties of a cord including a conventional chemically synthesized nylon lower-twisted yarn).

As described above, the cord includes a first lower twisted yarn and a second lower twisted yarn having a predetermined number of twists, and is formed by twisting the first lower twisted yarn and the second lower twisted yarn together. At this time, the filament for forming the first lower twisted yarn and the filament for forming the second lower twisted yarn are simultaneously lowered by a CC twisting machine (eg, cable corder twist machine) or a ring twisting machine, respectively, while the first lower twisting yarn is twisted. Since the yarn and the second lower twisted yarn are formed, the twist direction (first twist direction) of the first lower twist yarn and the twist direction (second twist direction) of the second lower twist yarn may be the same. And, when using a CC twisting machine (eg, cable corder twist machine) or a ring twisting machine (ring-twister), the upper twisting may be performed continuously following the lower twisting and simultaneously with the lower twisting, in the twist direction of the upper twist (ie, the third twisting direction) may be opposite to the first twisting direction (or second twisting direction).

The content of the lower twisted yarn in the cord affects the characteristics of the cord. For example, when the content of aramid is high, the high-speed running performance of the tire can be improved by the high modulus, but the fatigue performance is lowered because it receives a lot of load for the same deformation. In addition, when the content of nylon is high, the modulus of the initial part of the stress-strain curve pattern, which indicates the physical properties of the cord, is low, so that the load for the same deformation is reduced and the fatigue resistance performance is increased. The effect on driving performance is low. In the present application, in consideration of the above points, the content of the lower twisted yarn may be adjusted.

In an embodiment of the present application, the hybrid raw cord may include 20 to 50 wt% of the first lower twisted yarn based on 100 wt% of the total weight of the raw cord. Specifically, the lower limit of the content of the first lower twisted yarn may be, for example, more than 20 wt%, specifically 25 wt% or more, or 30 wt% or more, and more specifically 31 wt% or more, 32 wt% or more, 33 % or more, 34% or more, 35% or more, 36% or more, 37% or more, 38% or more, 39% or more, 40% or more, 41% or more, 42% or more, 43 weight % or greater, 44 weight % or greater, or 45 weight % or greater. And, the upper limit is, for example, less than 50% by weight, specifically 49% by weight or less, 48% by weight or less, 47% by weight or less, 46% by weight or less, 45% by weight or less, 44% by weight or less, 43% by weight or less or less, 42 wt% or less, 41 wt% or less, or 40 wt% or less.

In the raw code, the content of the remaining lower-twisted yarns (such as second lower-twisted yarns) staged together with the first lower-twisted yarn may be appropriately adjusted at a level that does not impair the above-described objectives of the present application. For example, when the raw cord is manufactured by twisting the first lower-twisted yarn and the second lower-twisted yarn, the content of the second lower-twisted yarn in the raw cord is an amount excluding the above-described first lower-twisted yarn content, that is, 50 to 80 weight. % can be More specifically, the content of the second lower-twisted yarn may be determined according to the above-described content of the first lower-twisted yarn.

When the content of the lower-twisted yarn in the cord is controlled within the above-mentioned range, the commercially required level of physical properties (that is, the level of physical properties of the cord including the conventional chemically synthesized nylon lower-twisted yarn) is secured, and driving performance and fatigue resistance characteristics are ensured. It is beneficial to ensure a balance between

The type of the heterogeneous resin fiber used to form the second lower twisted yarn may be selected at a level that does not impair the purpose of the present application. For example, the second lower twisted yarn may include at least one of polyester fibers, aromatic polyamide fibers, and polyketone fibers.

In one example, the second lower twisted yarn may include aramid fibers. That is, the second lower twisted yarn may be formed by imparting twist to the aramid fiber, and the hybrid cord of the present application may include a nylon lower twisted yarn (first lower twisted yarn) and an aramid lower twisted yarn (second lower twisted yarn). Aramid, which shows high modulus, has a small amount of change in modulus at room temperature and high temperature, so it is excellent in suppressing flat spots, which are deformed when a tire is parked for a long time, and is an advantageous material for providing high-quality tires.

In one example, the cord may be a two-ply or three-ply cord. For example, the cord may have a two-ply structure in which one first lower twisted yarn having the above-mentioned fineness and one second lower twisted yarn having the above-mentioned fineness are staged together. Alternatively, the cord may have a three-ply structure in which one first lower-twisted yarn having the above-mentioned fineness and two second lower-twisted yarns having the above-mentioned fineness are staged together.

In an embodiment of the present application, the code may be one in which the fineness and/or the number of twists of each of the lower twisted yarns are specified.

In one example, the first lower twisted yarn is formed by applying twist to a bio-nylon fiber having a fineness of 750 to 1100 denier, and the second lower twisted yarn is a different type of bio-nylon and a different resin fiber having a fineness of 900 to 1200 denier. It may be formed by giving twist. In this case, the number of twists of the first lower twisted yarn may be, for example, 300 TPM or more, and the upper limit thereof may be adjusted within the above-described range. Specific fineness may also be adjusted within the above-described range.

In another example, the first lower-twisted yarn is formed by giving twist to bio-nylon fibers having a fineness of 1100 to 1500 denier, and the second lower-twisted yarn is a heterogeneous resin fiber different from bio-nylon having a fineness of 1200 to 1800 denier. It may be formed by imparting twist to the . In this case, the number of twists of the first lower twisted yarn may be, for example, 400 TPM or less, and the upper limit thereof may be adjusted within the above-described range. Specific fineness may also be adjusted within the above-described range.

According to the embodiment of the present application, when the second lower-twisted yarn used together with the bio-nylon lower-twisted yarn that is the first lower-twisted yarn includes aramid fibers, the second lower-twisted yarn measured after untwisting the upper yarn with respect to the ply-twisted yarn (low cord or dip cord). The ratio of the length of the second lower twisted yarn to the first lower twisted yarn (the length of the second lower twisted yarn (L ₂ )/the length of the first lower twisted yarn (L ₁ )) may be in the range of 1.0 to 1.10 times. This is to improve the fatigue performance of the cord by lowering the initial modulus of the cord by making the second lower-twisted yarn (aramid lower-twisted yarn) having a higher modulus longer.

When the ratio of the length of the second lower twisted yarn to the first lower twisted yarn (the length of the second lower twisted yarn (L2) / the length of the first lower twisted yarn (L1)) is less than 1.0, the aramid with high modulus becomes shorter, indicating the tensile properties of the cord. In the stress-strain curve pattern, the modulus of the initial part is increased, which means that the code receives more load in the same deformation, and ultimately, the fatigue resistance performance is lowered. And, when the ratio of the length of the second lower twisted yarn to the first lower twisted yarn (the length of the second lower twisted yarn (L2) / the length of the first lower twisted yarn (L1)) exceeds 1.10, the aramid and the nylon are separated by force during the cord tension. may reduce the strength of the final code.

Specifically, the lower limit of the ratio may be, for example, 1.01 or more, 1.02 or more, 1.03 or more, 1.04 or more, or 1.05 or more, and the upper limit thereof is, for example, 1.09 or less, 1.08 or less, 1.07 or less, 1.06 or less, or 1.05 or less. can

In the embodiment of the present application, the length ratio control as described above is the amount of tension applied to each of the filaments forming the first lower twisted yarn and the filaments forming the second lower twisted yarn during the lower twisting and/or upper twisting process for manufacturing the cord. This can be done through control. More specifically, by making the magnitude of the tension applied to the aramid fiber (forming the second lower twisted yarn) smaller than the tension applied to the bionylon fiber forming the first lower twisted yarn, when the lower twist and upper twist are made, the second The length of the lower twisted yarn may be made longer than the length of the first lower twisted yarn.

The coating layer formed on the raw code means a layer formed from a coating solution capable of exhibiting a predetermined function. Such a coating layer may be formed on at least a portion of the aforementioned lower twisted yarn. The method of forming the coating layer is not particularly limited, and for example, the coating layer may be formed through a known dipping or spraying method.

The coating layer may be configured to impart predetermined characteristics to the cord or to reinforce the characteristics of the cord. For example, the coating layer may be a layer capable of imparting an adhesive function to the cord, but the properties imparted or reinforced by the coating layer are not limited only to the adhesive function.

In one example, the coating layer may be formed from an adhesive (composition). For example, the coating layer may include or be formed from a resorcinol-formaldehyde-latex (RFL) adhesive (composition), an epoxy adhesive (composition), or a urethane adhesive (composition). However, the adhesive component forming the coating layer is not limited to those described above.

Although not particularly limited, the adhesive composition may include an aqueous or non-aqueous solvent. These adhesives allow the fiber cord to exhibit improved adhesion to other adjacent constructions in tire reinforcement applications.

The hybrid cord having the above configuration may provide commercially required level of physical properties (ie, the level of physical properties of a cord including a conventional chemically synthesized nylon lower-twisted yarn). Such physical properties include, for example, strength, medium elongation, elongation at cut, dry heat shrinkage, adhesion, and fatigue resistance. In particular, since the hybrid cord of the present application is constructed and manufactured to supplement the high modulus properties of the bio-nylon lower-twisted yarn, it is possible to prevent deterioration of the expected elongation and fatigue resistance of the cord according to the use of the bio-nylon lower-twisted yarn having a high modulus. can

In one example, the strength of the hybrid cord may be greater than or equal to 20 kgf. Specifically, the strength may be, for example, 21 kgf or more, 22 kgf or more, 23 kgf or more, 24 kgf or more, or 25 kgf or more. The strength is similar to that of a cord including a conventional chemically synthesized nylon lower-twist yarn. The strength may be measured according to a method to be described later.

In one example, the median elongation (%, @4.5 kg) of the hybrid cord may be 2.8% or more. For example, the median elongation is 2.9% or more, 3.0% or more, 3.1% or more, 3.2% or more, 3.3% or more, 3.4% or more, 3.5% or more, 3.6% or more, 3.7% or more, 3.8% or more, 3.9% or more. or more, 4.0% or more, 4.1% or more, 4.2% or more, 4.3% or more, 4.4% or more, 4.5% or more, 4.6% or more, 4.7% or more, 4.8% or more, 4.9% or more, or 5.0% or more. The corresponding intermediate elongation is equivalent to or higher than the intermediate elongation of a cord including a conventional chemically synthesized nylon lower-twisted yarn. The median elongation may be measured according to a method to be described later.

The intermediate elongation can be adjusted or changed according to the number of twists. For example, when the number of twists in the cord is low, the modulus is high during the tensile test, and accordingly, the median elongation is lowered. When the number of twists is low, the modulus is higher due to the structural characteristics of the cord. The lower the number of twists in the cord length direction, the more oblique lines caused by the twist are erected in the cord length direction and the maximum force is received earlier, so the overall modulus is lowered. because it rises

In one example, the cut elongation (%) of the hybrid cord may be 7.0% or more. For example, the elongation at cut is 7.1% or more, 7.2% or more, 7.3% or more, 7.4% or more, 7.5% or more, 7.6% or more, 7.7% or more, 7.8% or more, 7.9% or more, 8.0% or more, 8.1% or more. or more, 8.2% or more, 8.3% or more, 8.4% or more, 8.5% or more, 8.6% or more, 8.7% or more, 8.8% or more, 8.9% or more, 9.0% or more, 9.1% or more, 9.2% or more, 9.3% or more, 9.4% or more, 9.5% or more, 9.6% or more, 9.7% or more, 9.8% or more, 9.9% or more, or 10% or more. The cut elongation is equivalent to or higher than the intermediate elongation of a cord including a conventional chemically synthesized nylon lower-twisted yarn. The cut elongation may be measured according to a method to be described later.

The breaking elongation may be adjusted or changed according to the number of twists. For example, the higher the twist, the lower the modulus, the more inclined the S-S curve pattern (stress-strain curve pattern), and as a result, the cutting elongation may be increased.

In one example, the dry heat shrinkage rate of the hybrid cord may be 1.2% or more. For example, the dry heat shrinkage rate may be 1.3% or more, 1.4% or more, 1.5% or more, 1.6% or more, 1.7% or more, 1.8% or more, 1.9% or more, or 2.0% or more. The dry heat shrinkage rate is similar to the dry heat shrinkage rate of a cord including a conventional chemically synthesized nylon lower-twisted yarn. The dry heat shrinkage rate may be measured according to a method to be described later.

In one example, the adhesive force of the hybrid cord may be 12.5 kgf or more. For example, the adhesive strength is 12.6 kgf or more, 12.7 kgf or more, 12.8 kgf or more, 12.9 kgf or more, 13.0 kgf or more, 13.1 kgf or more, 13.2 kgf or more, 13.3 kgf or more, 13.4 kgf or more, 13.5 kgf or more, 13.6 kgf or more. , 13.7 kgf or more, 13.8 kgf or more, 13.9 kgf or more, or 14.0 kgf or more. The adhesive strength is at a similar level compared to the adhesive strength of a cord including a conventional chemically synthesized nylon lower-twisted yarn. The adhesive force may be measured according to a method to be described later.

In one example, the strength retention rate after 8 hours fatigue of the hybrid cord may be 90% or more. For example, the strength retention rate after 8 hours fatigue may be 90.5% or more, 91.0% or more, 91.5% or more, 92.0% or more, 92.5% or more, or 93.0% or more. The strength retention after 8 hours fatigue as described above is equivalent to or higher than the strength retention ratio after 8 hours fatigue of a cord including a conventional chemically synthesized nylon lower-twisted yarn. The strength retention rate after 8 hours fatigue may be measured according to a method to be described later.

In one example, the strength retention rate after 16 hours fatigue of the hybrid cord may be 70% or more. For example, the strength retention rate after 16 hours fatigue is 70.5% or more, 71.0% or more, 71.5% or more, 72.0% or more, 72.5% or more, 73.0% or more, 73.5% or more, 74.0% or more, 74.5% or more, 75.0% or more. or more, 75.5% or more, 76.0% or more, 76.5% or more, 77.0% or more, 77.5% or more, 78.0% or more, 78.5% or more, 79.0% or more, 79.5% or more, or 80.0% or more. The strength retention after 16 hours of fatigue as described above is equivalent to or greater than the retention of strength after 16 hours of fatigue of a cord including a conventional chemically synthesized nylon lower-twisted yarn. The strength retention rate after 16 hours of fatigue may be measured according to a method to be described later.

In the embodiment of the present application, the characteristics of the hybrid cord may be different depending on the configuration of the cord.

For example, in one embodiment of the hybrid cord of the present application, the first lower twisted yarn is formed by giving a twist to a bio-nylon fiber having a fineness of 750 to 1100 denier, and the second lower twisted yarn has a fineness of 900 to 1200 denier. It is formed by imparting twist to a different type of resin fiber different from bio nylon having In this case, the median elongation of the cord is, for example, 3.8% or more, 3.9% or more, 4.0% or more, 4.1% or more, 4.2% or more, 4.3% or more, 4.4% or more, 4.5% or more, 4.6% or more, 4.7% or more. or more, 4.8% or more, 4.9% or more, or 5.0% or more. In addition, the cut elongation of the cord is, for example, 8.5% or more, 8.6% or more, 8.7% or more, 8.8% or more, 8.9% or more, 9.0% or more, 9.1% or more, 9.2% or more, 9.3% or more, 9.4% or more. , 9.5% or more, 9.6% or more, 9.7% or more, 9.8% or more, 9.9% or more, or 10% or more. And, in the case of the code as described above, the strength retention after 8 hours fatigue may be 91.0% or more, 91.5% or more, 92.0% or more, 92.5% or more, or 93.0% or more, and the strength retention rate after 16 hours fatigue is 75.0% or more, 75.5 % or more, 76.0% or more, 76.5% or more, 77.0% or more, 77.5% or more, 78.0% or more, 78.5% or more, 79.0% or more, 79.5% or more, or 80.0% or more.

In another embodiment related to the hybrid cord of the present application, the first lower twisted yarn is formed by giving a twist to a bio nylon fiber having a fineness of 750 to 1100 denier, and the second lower twisted yarn is a bio nylon having a fineness of 900 to 1200 denier. It is formed by imparting twist to a different type of resin fiber, and a ply-twisted yarn having a twist number of the first lower twisted yarn, for example, 300 or more and less than 350 TPM may be used. In this case, the median elongation of the cord is, for example, 2.8% or more, 2.9% or more, 3.0% or more, 3.1% or more, 3.2% or more, 3.3% or more, 3.4% or more, 3.5% or more, 3.6% or more, 3.7% or more. or more, 3.8% or more, 3.9% or more, or 4.0% or more. In addition, the cut elongation of the cord is, for example, 7.0% or more, 7.1% or more, 7.2% or more, 7.3% or more, 7.4% or more, 7.5% or more, 7.6% or more, 7.7% or more, 7.8% or more, 7.9% or more. , 8.0% or more, 8.1% or more, 8.2% or more, 8.3% or more, 8.4% or more, 8.5% or more, 8.6% or more, 8.7% or more, 8.8% or more, 8.9% or more, or 9.0% or more. And, in the case of the ply-twisted yarn as described above, the strength retention after 8 hours fatigue may be 90% or more, 90.5% or more, or 91.0% or more, and the strength retention after 16 hours fatigue is 70% or more, 70.5% or more, 71.0% or more, 71.5% or more, 72.0% or more, 72.5% or more, 73.0% or more, 73.5% or more, 74.0% or more, 74.5% or more, or 75.0% or more.

In another example related to the present application, the present application relates to a method of manufacturing an eco-friendly cord including a bio-based fiber. Specifically, the method may be a method of manufacturing the above-described code.

In the case of fibers, for example, synthetic fibers manufactured through a thermal melting process, heat setting may be performed so that molecular chains are well oriented in the fiber length direction in order to express strength and modulus properties suitable for the use. On the other hand, when the heat-setting fiber is subjected to a temperature higher than the glass transition temperature, it returns to its original curly shape. In this case, the modulus is lowered. In this regard, when a low tension is applied during heat treatment for producing a dip cord, the molecular chain returns to its original shape and the modulus is lowered, and when a high tension is applied, the molecular chain is maintained in an oriented state or The more oriented, the higher the modulus. The inventor of the present application controls the tension applied to the ply-twisted yarn having the above-described configuration in a predetermined range when forming the coating layer in consideration of the above-described thermal characteristics of the fiber and the dip code manufacturing process.

Specifically, the method includes a first lower twisted yarn formed by applying twist to a bio-nylon fiber having a fineness of 600 to 2000 denier, and a first formed by applying twist to a heterogeneous resin fiber different from nylon having a fineness of 800 to 2200 denier. 2 preparing a ply-twisted yarn staged together with a lower twisted yarn; and forming a coating layer on the ply-twisted yarn while applying tension to the ply-twisted yarn. At this time, the tension applied to the ply-twisted yarn is 1.0 kg/cord or less . The number of twists applied to the first lower twisted yarn is in the range of 250 to 600 TPM, and the hybrid raw cord includes 20 to 50 wt% of the first lower twisted yarn based on 100 wt% of the total weight. The hybrid cord manufactured according to the above method satisfies a strong retention rate of 90% or more after an 8-hour disk fatigue test conducted according to the JIS-L 1017 method of the Japanese Standard Association (JSA).

In one example, the tension applied to the ply-twisted yarn is 0.1 kg/cord or more, 0.2 kg/cord or more, 0.3 kg/cord or more, 0.4 kg/cord or more, 0.5 kg/cord or more, 0.6 kg/cord or more, 0.7 kg/cord or more, 0.8 kg/cord or more, or 0.9 kg/cord or more. And, the upper limit is, for example, less than 0.9 kg / cord, less than 0.8 kg / cord, less than 0.7 kg / cord, less than 0.6 kg / cord, less than 0.5 kg / cord, less than 0.4 kg / cord, less than 0.3 kg / cord or 0.2 kg/cord or less.

As described above, the method includes forming a coating layer on the ply-twisted yarn while applying tension to the ply-twisted yarn (low cord) including the bio-derived nylon lower-twisted yarn. In this case, 'coating layer formation' may mean that the coating composition (coating solution) is applied on the raw code. The applied coating composition may be subjected to heat treatment such as drying or curing, which will be described later. In this case, the coating layer may mean a layer obtained through heat treatment.

A method of applying the coating composition (coating solution) on the rocode is not particularly limited, and, for example, immersion or spraying may be used. For example, the method may include spraying a coating layer forming composition (coating solution) on the ply-twisted yarn (low code). That is, in the method, the coating layer may be formed by spraying the coating layer forming composition (coating solution) on the ply-twisted yarn. In another example, the method may include immersing the ply-twisted yarn (low code) in the coating layer forming composition (coating solution). That is, in the method, the coating layer may be formed by immersing the ply-twisted yarn in the coating layer forming composition (coating solution). When the ply-twisted yarn is dipping in the coating composition (coating solution), a specific method of dipping the ply-twisted yarn into the coating composition is not particularly limited. For example, a method of immersing the ply-twisted yarn in a coating bath filled with the coating composition while transferring the ply-twisted yarn or a fiber base including the same using a roll may be used. The cord coated with the coating composition after immersion may be referred to as a dip cord.

In one example, the coating layer may be formed while passing through the process of transferring the cord, applying a coating composition to the cord (spraying or immersing), and/or a subsequent heat treatment process. For example, the coating layer forming step (process) made while applying tension may include one or more processes of transferring the cord, immersion (or spraying), and heat treatment. Specifically, the coating layer forming step (process) made while applying a tension, heat treatment while applying a tension of the above-described size to the ply-twisted yarn to which the coating composition is already applied; Applying the coating composition to the ply-twisted yarn and performing heat treatment while applying the tension of the size described above; Alternatively, it may include transferring the ply-twisted yarn, applying the coating composition, and performing heat treatment while applying the above-mentioned magnitude of tension.

In an embodiment of the present application, the heat treatment may be performed at a temperature within a predetermined range. For example, the heat treatment may be performed at a temperature of 50 °C or higher, specifically, at a temperature in the range of 60 to 350 °C. Although not particularly limited, the heat treatment may be performed for 10 to 300 seconds.

In one example, the method may include two or more heat treatment steps. Specifically, the method includes a first heat treatment step made at a temperature of 60 to 220 ℃; And it may include a second heat treatment step made at a temperature of 200 to 350 ℃. The time period during which the heat treatment is performed is not particularly limited, but, for example, each of these heat treatments may be performed for about 10 to 300 seconds.

In one example, the temperature at which the first heat treatment is performed may be lower than the temperature at which the second heat treatment is performed. Specifically, the first heat treatment temperature may be in the range of 70 to 180 ℃, the second heat treatment temperature may be in the range of 200 to 300 ℃. In this case, the first heat treatment performed at a relatively low temperature may be referred to as a drying process, and the second heat treatment performed at a relatively high temperature may be referred to as a curing process.

In one example, the coating layer forming step (process) performed while applying the tension may be used in the sense of including heat treatment while applying a tension of the above-described size to the ply-twisted yarn to which the coating composition has been applied. More specifically, the coating layer forming step (process) performed while applying the tension includes performing a second heat treatment while applying a tension of the above-described size to the ply-twisted yarn performed up to the first heat treatment after the coating composition is applied can be used for meaning. Since high temperature heat treatment, particularly the second heat treatment, greatly affects the final physical properties of the cord, it is important to satisfy the above-described tension range. Therefore, the tension in the above-mentioned range can be maintained at least during the heat treatment, more specifically, the second heat treatment, and in addition to the transfer and immersion (spray) for forming the coating layer, and the first heat treatment process, the same or different (slightly different) can be changed.

In one example, the immersion or spraying may be performed one or more times. When immersion or spraying is performed two or more times, the components of the coating composition used for each immersion or spraying may be the same or different.

For example, the first immersion, the second immersion, and the heat treatment may be sequentially performed. In this case, the heat treatment may sequentially include a first heat treatment (eg, drying) and/or a second heat treatment (eg, curing).

In another example, the first immersion, heat treatment, second immersion and heat treatment may be sequentially performed. In this case, the heat treatment performed between the first immersion and the second immersion may be a drying process made at a relatively low temperature, and the heat treatment performed after the second immersion may be a hardening process made at a relatively high temperature.

In one example, in the method, a bio-derived nylon fiber (filament) is lower-twisted in a first twist direction to produce a first lower twisted yarn, and at the same time, a second lower twisted yarn is lowered by lowering a heterogeneous fiber (filament) in a second twist direction. may be a method of manufacturing

In one example, the method may be a method of manufacturing a ply-twisted yarn by twisting the first and second lower-twisted yarns in a third twist direction after or simultaneously with the production of the lower-twisted yarn as described above. In this case, the first twisting direction and the second twisting direction may be the same, and the first twisting direction and the third twisting direction may be different from each other.

According to an embodiment of the present application, a twisting machine that simultaneously performs lower twisting and upper twisting, such as a cable coder, may be used to manufacture a ply-twisted yarn. For example, in the case of manufacturing a hybrid cord, the first lower twisted yarn forming filament (bio-derived nylon filament yarn) and the second lower twisted yarn forming filament (e.g., aramid, etc.) are simultaneously produced by one twisting machine (e.g., cable corder). Since the first lower-twisted yarn and the second lower-twisted yarn are respectively lower-twisted, the twisting direction (first twisting direction) of the first lower twisted yarn and the second twisting direction (second twisting direction) of the lower twisted yarn may be the same. In addition, according to an embodiment of the present application performed using a twisting machine such as a cable coder capable of performing both lower and upper twisting at the same time, following the lower twisting, the lowering and lowering twisting may be performed continuously and simultaneously, such a stage The twist direction (ie, the third twist direction) may be opposite to the first twist direction (or the second twist direction).

In one example, the method may be a method of forming the second lower twisted yarn by imparting a twist number within the range of 250 to 600 TPM to the fibers (filaments) forming the second lower twisted yarn. That is, the number of twists imparted to the second lower twisted yarn is in the range of 250 to 600 TPM.

In one example, the method may form a ply-twisted yarn by twisting the first lower-twisted yarn and the second lower-twisted yarn with a twist number within a range of 250 to 600 TPM.

In one example, the method provides twist to a bio-nylon fiber having a fineness of 750 to 1100 denier to form the first lower twisted yarn, and twisting to a heterogeneous resin fiber different from the bio-nylon having a fineness of 900 to 1200 denier. to form the second lower twisted yarn. In this case, the number of twists applied to the first lower twisted yarn may be 300 TPM or more, and the upper limit thereof may be adjusted within the above-described range. Specific fineness can also be adjusted within the above-mentioned range.

In one example, the method imparts twist to a bio-nylon fiber having a fineness of 1100 to 1500 denier to form the first lower twisted yarn, and twisting to a heterogeneous resin fiber different from the bio-nylon having a fineness of 1200 to 1800 denier to form the second lower twisted yarn. In this case, the number of twists of the first lower twisted yarn may be, for example, 400 TPM or less, and the upper limit thereof may be adjusted within the above-described range. Specific fineness may also be adjusted within the above-described range.

In an embodiment of the present application, the second lower twisted yarn used together with the first lower twisted bio-nylon lower twisted yarn may include aramid fibers. In this case, the method determines the magnitude of the tension applied to the aramid fiber (forming the second lower twisted yarn) when the lower twisting and/or upper twisting is made, rather than the tension applied to the bionylon fiber (forming the first lower twisted yarn). It may be a way to control smaller. Through this, the ratio of the length of the second lower-twisted yarn to the first lower-twisted yarn (length of the second lower-twisted yarn (L ₂ )/length of the first lower-twisted yarn) measured after untwisting the upper yarn with respect to the ply-twisted yarn (low code or deep code). (L ₁ )) can be adjusted in this 1.0 to 1.10 times range.

With respect to the manufacturing method of the present application, in addition to the above-described descriptions of the configuration, characteristics, and manufacture of the cord and the lower twisted yarn forming the same are the same as those described in the hybrid cord, and thus will be omitted.

As described above, the ply-twisted yarn (low code) formed including the bio-derived nylon lower-twisted yarn has poor physical property balance due to the characteristics of the bio-derived nylon yarn with a low intermediate elongation (ie, high modulus) (for example, , poor strength properties after fatigue). However, as described above, the method of the present application for controlling the properties of the fibers (eg, the type of fibers, the number of twists, the fineness, the content, etc.) and the tension at the time of forming the coating layer within a predetermined range is a bio-derived nylon lower-twisted yarn with high modulus. While using, it is possible to provide the same or higher level of elongation characteristics and strength retention after fatigue compared to conventional cords including chemically synthesized nylon lower-twisted yarns.

In another example related to the present application, the present application relates to a rubber composite or rubber reinforcement including the cord. The rubber composite or rubber reinforcing material may further include a rubber substrate such as a rubber sheet in addition to the above-described code.

In another example related to the present application, the present application relates to a tire including the cord. The tire may have a generally known configuration such as a tread, shoulder, sidewall, cap ply, belt, carcass (or body ply), inner liner, bead, and the like.

According to the present application, a hybrid cord that includes a bio-derived nylon lower-twist yarn and meets the commercially required level of physical properties in relation to strength, medium elongation, cut elongation, dry heat shrinkage, adhesion, and/or fatigue resistance, etc. is provided In particular, the present application includes a bio-derived nylon lower-twisted yarn having a higher modulus compared to chemically synthesized nylon, while elongation and fatigue resistance properties are commercially required (that is, a cord including a conventional chemically synthesized nylon lower-twisted yarn has level) has the effect of the invention to provide a hybrid code that is equal to or greater than the level.

Hereinafter, the operation and effect of the invention will be described in more detail through specific examples of the invention. However, this is presented as an example of the invention and the scope of the invention is not limited in any sense by this.

<Experiment 1: Evaluation of yarn properties>

The comparative evaluation of the physical properties of Chemicla Nylon and Bio-based Nylon yarn measured according to ASTM D885 is as follows. An Instron tester (Instron Engineering Corp., Canton, Mass) was used to measure the tensile properties, a Testrite was used to measure the hot air shrinkage, and an oven and Instron were used to measure the heat resistance strength retention rate. A tester was used.

	Chemical Nylon PA 66	Bio-based nylon PA 56
fineness (detex)	Approx. 940±18	938
Breaking strength (N)	≥ 78.0	≥ 79.7
Tenacity (cN/dtex)	≥ 8.3	≥ 8.5
elongation at break (%)	19.0±3.0	18.4
Medium elongation (4.7 Constant load elongation of cN/ dtex) (%)	12.0±1.5	10.1
Hot air shrinkage (177℃*2min) (%)	6.2±1.5	7.2
Heat resistance strength retention rate(180℃*4h) (%)	90	93.7

It is confirmed that Bio-based Nylon has a lower intermediate elongation (ie, higher modulus) and a lower elongation at break (elongation at break) than Chemical Nylon, assuming that it has a similar fineness. It is confirmed that the dry heat shrinkage rate of Bio-based Nylon is generally higher than that of Chemical Nylon due to the characteristics of other yarns.

<Evaluation of properties of hybrid code 1>

Example 1

About 1000 denier aramid filament yarn and about 840 denier Bio-based Nylon (PA 56) filament yarn are put into the cable cord twister (Allma’s Cable Corder), and the lower edge in the Z-direction and the upper edge in the S-direction are performed at the same time, respectively. was carried out to prepare a 2-ply cabled yarn (low code). At this time, the cable cord twisting machine was set with a twist number of 360 TPM (twist per meter) for the lower and upper twisting, and by adjusting the tension applied to the nylon filament yarn and the aramid filament yarn, respectively, the ply-twisted yarn (low cord) so that the ratio of the length of the nylon (Bio-Based Nylon) single yarn (lower twisted yarn) to the aramid single yarn (lower twisted yarn) length (= aramid single yarn length ( _LA )/Bio-Based Nylon single yarn length (L _N )) is 1.01 did. To obtain the length ratio of aramid single yarn and Bio-Based Nylon single yarn, apply a 0.05 g/d load to a 1 m long ply-twisted yarn (low code) sample and untwist the upper strand to separate the aramid single yarn and Bio-Based Nylon single yarn from each other. , The length of the aramid single yarn and the length of the Bio-Based Nylon single yarn were measured under a load of 0.05 g/d, respectively. The raw cord prepared as described above contains about 45.7 wt% of the first lower-twisted yarn (including bio-nylon fibers) and about 54.3 wt% of the second lower-twisted yarn (including aramid fibers).

Then, the ply-twisted yarn (low code) was prepared with 2.0 wt% resorcinol, 3.2 wt% formalin (37%), 1.1 wt% sodium hydroxide (10%), 43.9 wt% styrene/butadiene/vinylpyridine ( 15/70/15) was dipped in a resorcinol-formaldehyde-latex (RFL) adhesive solution containing rubber (41%) and water. A hybrid tire cord was completed by drying the ply-twisted yarn (raw cord) containing the RFL solution by immersion at 150° C. for 100 seconds and heat treatment (curing) at 240° C. for 100 seconds. The tension applied to the ply-twisted yarn during the immersion, drying, and heat treatment processes was 0.6 kg/cord.

Example 2

A hybrid cord was prepared in the same manner as in Example 1, except that the tension applied to the ply-twisted yarn during coating was 0.3 kg/cord.

Reference Example 1

A hybrid cord was prepared in the same manner as in Example 1, except that 840 denier Chemical Nylon (PA 66) was used instead of 840 denier Bio-Based Nylon, and the tension applied to the ply-twisted yarn during coating was 0.8 kg. did.

Comparative Example 1

A hybrid cord was prepared in the same manner as in Example 1, except that the tension applied to the ply-twisted yarn during coating was 1.5 kg/cord.

Comparative Example 2

A hybrid cord was prepared in the same manner as in Example 1, except that the tension applied to the ply-twisted yarn during coating was 1.1 kg/cord.

Examples 1 and 2, Reference Examples 1 and Comparative Examples 1 and 2, the physical property evaluation method for the prepared cords and the results (Table 2) are as follows.

* Strength (kgf) : Hybrid cord by applying a tensile speed of 300 m/min to 10 samples of 250 mm using an Instron testing machine (Instron Engineering Corp., Canton, Mass) according to the ASTM D-885 test method. The strength (arithmetic mean value) of was measured.

* Medium elongation (%) (@4.5kgf) : 300 m/min tensile for 10 samples of 250 mm using an Instron testing machine (Instron Engineering Corp., Canton, Mass) according to ASTM D-885 test method The elongation (arithmetic mean value) of the hybrid cord at 4.5 kgf was measured by applying speed.

* Elongation at cut (%) : According to ASTM D-885 test method, using an Instron testing machine (Instron Engineering Corp., Canton, Mass), a hybrid by applying a tensile speed of 300 m/min to 10 samples of 250 mm The cut elongation (arithmetic mean value) of the cord was measured.

* Dry heat shrinkage (%) : According to the dry heat shrinkage measurement method stipulated in ASTM D885, the shrinkage was measured after standing at a temperature of 177° C. for 2 minutes using a Testright instrument.

* Adhesion (kgf) : The adhesion of the hybrid cord to the rubber was measured using the H-Test method specified in ASTM D885. This is a measure of the force applied when a single cord is pulled out of the rubber.

* Fatigue resistance (Fatigue 8H, ±5% (%)) : After preparing a sample by vulcanizing a hybrid tire cord with measured strength (strength before fatigue) to rubber, Fatigue was applied to the sample by repeating tension and contraction within ±5% for 8 hours while rotating at a speed of 2500 rpm at 80° C. using a Disk Fatigue Tester according to the JIS-L 1017 method. . Then, after removing the rubber from the sample, the strength after fatigue of the hybrid tire cord was measured. The strength retention rate defined by Equation 1 below was calculated based on the strength before fatigue and strength after fatigue.

<Equation 1>: Strong retention rate (%) = [Strength after fatigue (kgf)/Strength before fatigue (kgf)] × 100

Here, the strength (kgf) before and after fatigue is, according to ASTM D-885 test method, 300 m/min tensile speed for a sample of 250 mm using an Instron tester (Instron Engineering Corp., Canton, Mass). It was obtained by measuring the strength at break of the hybrid tire cord while applying .

* Fatigue resistance properties (Fatigue 16H, ±5% (%)) : Measurements were made in the same manner as the aforementioned fatigue resistance properties (Fatigue 8H, ±5% (%)), except that tension and contraction were performed for 16 hours.

	Example 1	Example 2	Reference Example 1	Comparative Example 1	Comparative Example 2
Types of Nylon Bottom Twist Yarns	PA 56	PA 56	PA 66	PA 56	PA 56
Twists (TPM)*	360	360	360	360	360
Tension at coating (kgf/cord)**	0.6	0.3	0.8	1.5	1.1
Strong (kgf)	25.1	25.2	25.3	25.3	25.4
Medium elongation@4.5kgf(%)	4.0	4.5	4.1	3.0	3.5
Elongation at cut (%)	9.3	9.9	9.6	7.5	8.2
Dry heat shrinkage (%)	1.6	1.4	1.6	2.1	1.8
Adhesion (kgf)	13.3	13.8	13.7	13.7	13.0
Fatigue 8H, ±5% (%)	91.5	92.8	92.7	82.3	84.7
Fatigue 16H, ±5% (%)	76.8	80.1	77.2	68.4	70.3
*Number of twists: When manufacturing the cords of Examples and Comparative Examples, the number of twists set for each lower twisted yarn and the set number of twists when twisting the lower twisted yarn are the same. **Tension during coating: In relation to the formation of the RFL adhesive coating layer, it refers to the tension applied in the process including heat treatment.

Comparing the characteristics of the example using PA56 and the comparative example, it was confirmed that the code of the comparative example had a low intermediate elongation (high initial modulus on the s-s curve pattern) and deteriorated fatigue resistance. On the other hand, the code of the example shows characteristics equal to or higher than that of Reference Example 1 using PA66.

<Evaluation of properties of hybrid code 2>

Example 3

A hybrid cord was manufactured in the same manner as in Example 1, except that the number of twists was set to 335 TPM during the manufacture of the ply-twisted yarn, and the tension applied to the ply-twisted yarn during coating was set to 1.0 kg/cord.

Example 4

A hybrid cord was prepared in the same manner as in Example 3, except that the tension applied to the ply-twisted yarn during coating was 0.8 kg/cord.

Reference Example 2

A hybrid cord was prepared in the same manner as in Example 3, except that 840 denier Chemical Nylon (PA 66) was used instead of 840 denier Bio-Based Nylon, and the tension applied to the ply-twisted yarn during coating was 1.2 kg. did.

Comparative Example 3

A hybrid cord was prepared in the same manner as in Example 3, except that the tension applied to the ply-twisted yarn during coating was 2.0 kg/cord.

Comparative Example 4

A hybrid cord was prepared in the same manner as in Example 3, except that the tension applied to the ply-twisted yarn during coating was 1.5 kg/cord.

The results of evaluation of physical properties of the cords prepared in Examples 3-4, Reference Example 2 and Comparative Example 3-4 are shown in Table 3 below. The physical property evaluation method described in Table 3 is the same as described above.

	Example 3	Example 4	Reference Example 1	Comparative Example 1	Comparative Example 2
Types of Nylon Bottom Twist Yarns	PA 56	PA 56	PA 66	PA 56	PA 56
Twists (TPM)*	335	335	335	335	335
Tension at coating (kgf/cord)**	1.0	0.8	1.2	2.0	1.5
Strong (kgf)	25.4	24.8	25.6	25.1	25.5
Medium elongation@4.5kgf(%)	3.1	3.3	3.1	2.3	2.6
Elongation at cut (%)	7.5	7.7	7.7	6.3	6.9
Dry heat shrinkage (%)	1.8	1.6	1.8	2.4	2.0
Adhesion (kgf)	13.0	13.6	13.1	12.8	13.5
Fatigue 8H, ±5% (%)	90.1	90.6	90.3	78.4	83.6
Fatigue 16H, ±5% (%)	74.3	77.6	76.4	66.7	67.1
*Number of twists: When manufacturing the cords of Examples and Comparative Examples, the number of twists set for each lower twisted yarn and the set number of twists when twisting the lower twisted yarn are the same. **Tension during coating: In relation to the formation of the RFL adhesive coating layer, it refers to the tension applied in the process including heat treatment.

Comparing the characteristics of the example using PA56 and the comparative example, it was confirmed that the code of the comparative example had a low intermediate elongation (high initial modulus on the s-s curve pattern) and deteriorated fatigue resistance. On the other hand, the code of the example shows characteristics equal to or higher than that of Reference Example 1 using PA66.

Claims (20)

1. A hybrid raw cord and a coating layer formed on the hybrid raw cord,

   The hybrid raw cord includes: a first lower twisted yarn formed by twisting bio-nylon fibers having a fineness of 600 to 2000 denier; and a second lower twisted yarn formed by imparting twist to a heterogeneous resin fiber different from bio-nylon having a fineness of 800 to 2200 denier,

   The number of twists of the first lower twisted yarn is in the range of 250 to 600 TPM,

   20 to 50% by weight of the first lower twisted yarn based on 100% by weight of the total weight of the hybrid raw cord,

   After an 8-hour disk fatigue test conducted according to the JIS-L 1017 method of the Japanese Standard Association (JSA), the strength retention rate satisfies 90% or more,

   Hybrid cord.
2. The method of claim 1,

   The number of twists of the second lower twisted yarn is in the range of 250 to 600 TPM, a hybrid cord.
3. The method of claim 1,

   The hybrid raw code is a hybrid cord, wherein the first lower twist yarn and the second lower twist yarn are formed in a range of 250 to 600 TPM.
4. The method of claim 1,

   The second lower twisted yarn is a hybrid cord formed by giving twist to the aramid fiber.
5. The method of claim 1,

   The first lower twisted yarn is formed by applying twist to bio-nylon fibers having a fineness of 750 to 1100 denier,

   The second lower twisted yarn is formed by imparting twist to a heterogeneous resin fiber different from bio-nylon having a fineness of 900 to 1200 denier,

   hybrid code.
6. 6. The method of claim 5,

   The number of twists of the first lower twisted yarn is 300 TPM or more, a hybrid cord.
7. The method of claim 1,

   The first lower twisted yarn is formed by applying twist to bio-nylon fibers having a fineness of 1100 to 1500 denier,

   The second lower twisted yarn is formed by imparting twist to a heterogeneous resin fiber different from bio-nylon having a fineness of 1200 to 1800 denier,

   hybrid code.
8. 8. The method of claim 7,

   The number of twists of the first lower twisted yarn is 400 TPM or less, a hybrid cord.
9. The method of claim 1,

   Hybrid cord that satisfies 70% or more of strong retention after 16-hour disk fatigue test conducted according to the JIS-L 1017 method of the Japanese Standard Association (JSA)
10. The method of claim 1,

    The hybrid cord is 2.8% at 4.5 kgf A hybrid cord having a medium elongation of greater than or equal to.
11. A first lower twisted yarn formed by applying twist to a bio-nylon fiber having a fineness of 600 to 2000 denier, and a second lower twisted yarn formed by applying twist to a heterogeneous resin fiber different from nylon having a fineness of 800 to 2200 denier preparing a plying speech; and

    It is a method of manufacturing a hybrid cord comprising the step of forming a coating layer on the ply-twisted yarn while applying tension to the ply-twisted yarn,

    The number of twists imparted to the first lower twisted yarn is in the range of 250 to 600 TPM,

    The hybrid raw cord contains 20 to 50% by weight of the first lower twisted yarn based on 100% by weight of the total weight,

    The tension applied to the ply-twisted yarn is 1.0 kg/cord or less,

    The hybrid cord is a method of manufacturing a hybrid cord, wherein the strength retention rate is 90% or more after an 8-hour disk fatigue test conducted according to the JIS-L 1017 method of the Japanese Standard Association (JSA).
12. 12. The method of claim 11,

    The number of twists imparted to the second lower twisted yarn is in the range of 250 to 600 TPM, a method of manufacturing a hybrid cord.
13. 12. The method of claim 11,

    A method of manufacturing a hybrid cord by twisting the first lower-twisted yarn and the second lower-twisted yarn with a twist number within a range of 250 to 600 TPM to form a ply-twisted yarn.
14. 12. The method of claim 11,

    The second lower twisted yarn will be formed by giving twist to the aramid fiber, a method for producing a hybrid cord.
15. 12. The method of claim 11,

    The first lower twisted yarn is formed by imparting twist to the bio-nylon fiber having a fineness of 750 to 1100 denier, and twist is given to a heterogeneous resin fiber different from the bio-nylon having a fineness of 900 to 1200 denier to give the second lower twisted yarn Forming a, hybrid cord manufacturing method.
16. 16. The method of claim 15,

    The method of manufacturing a hybrid cord, wherein the number of twists applied to the first lower twisted yarn is 300 TPM or more.
17. 12. The method of claim 11,

    The first lower twisted yarn is formed by applying twist to the bio-nylon fiber having a fineness of 1100 to 1500 denier, and twisting is applied to a heterogeneous resin fiber different from the bio-nylon having a fineness of 1200 to 1800 denier to give the second lower twisted yarn Forming a, hybrid cord manufacturing method.
18. 18. The method of claim 17,

    The method for manufacturing a hybrid cord, wherein the number of twists applied to the first lower twisted yarn is 400 TPM or less.
19. 12. The method of claim 11,

    The hybrid cord is a method of manufacturing a hybrid cord, which satisfies a strong retention rate of 70% or more after a 16-hour disk fatigue test conducted according to the JIS-L 1017 method of the Japanese Standard Association (JSA).
20. 12. The method of claim 11,

    The hybrid cord is 2.8% at 4.5 kgf A method for producing a hybrid cord, having an intermediate elongation of more than one.