KR20180035400A - Hybrid Tire Cord and Method for Manufacturing The Same - Google Patents

Abstract

A high-performance hybrid tire cord and a manufacturing method thereof for realizing the high performance conversion and weight reduction of tires are disclosed. The hybrid tire cord comprises: PET twisted yarn; aramid twisted yarn; and an adhesive coated on the PET twisted yarn and the aramid twisted yarn. In the hybrid tire cord having a predetermined length, after the twisted yarns are untwisted, the length of the aramid twisted yarn is 1 to 1.1 times the length of the PET twisted yarn.

Description

Technical Field [0001] The present invention relates to a hybrid tire cord and a manufacturing method thereof,

TECHNICAL FIELD The present invention relates to a hybrid tire cord and a manufacturing method thereof, and more particularly, to a high performance hybrid tire cord capable of realizing high performance and light weight of a tire and a manufacturing method thereof.

Background Art [0002] As a reinforcing material for rubber products such as tires, conveyor belts, V-belts, hoses and the like, fiber cords, in particular, fiber cords treated with adhesives (so-called "dip cords") have been widely used. The material of the fiber cord includes nylon fiber, polyester fiber, and rayon fiber. One of the important ways to improve the performance of finished rubber products is to improve the properties of the fiber cords used as reinforcements.

The fiber cord used as a reinforcing material of a tire is referred to as a tire cord. The driving speed of the vehicle is gradually increasing due to the improvement of the car performance and the improvement of the road condition. Therefore, studies on the tire cord that can maintain the stability and durability of the tire at high speeds are being actively conducted.

In addition, as the demand for environmentally friendly vehicles increases, weight reduction of vehicles for high fuel consumption is becoming a big issue, and research on light weight of tires has also been actively conducted.

A tire, which is a composite of fibers / metal / rubber, comprises a tread that is located at an outermost position and contacts the road surface, a cap ply under the tread, a belt under the cap fly, And carcass.

In order to reduce the weight of the tire, it is necessary to improve the performance of the tire cord.

Hybrid tire cords made of nylon and aramid have been developed as a part of high performance tire cords. However, the hybrid tire cords exhibit nylon properties at an early stage on the S-S curve pattern and exhibit low modulus.

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a hybrid tire cord and a method of manufacturing the same that can prevent problems due to limitations and disadvantages of the related art.

One aspect of the present invention is to provide a high performance hybrid tire cord capable of realizing high performance and light weight of a tire.

Another aspect of the present invention is to provide a method for manufacturing a high performance hybrid tire cord capable of realizing high performance and light weight of a tire with high productivity and low cost while minimizing physical property variations.

Other features and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description. Alternatively, other features and advantages of the present invention may be understood through practice of the present invention. Objects and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims of this invention.

According to one aspect of the present invention as described above, there is provided a hybrid tire cord comprising: Aramid Downward; And an adhesive coated on the aramid lower yarn, wherein the PET lower yarn and the aramid lower yarn are staggered together, and in the hybrid tire cord of a predetermined length, after the untwist of the stitch, And the length is 1 to 1.1 times the length of the PET underfill.

Wherein the PET underlayment has a first twist direction, the aramid underfill has a second twist direction, the PET underfill and the aramid underfire come together in a third twist direction, and the second twist direction is the first twist Direction, and the third twist direction is opposite to the first twist direction.

The weight ratio of the PET underlayer to the aramid underlay may be 20:80 to 80:20.

The hybrid tire cord may have a breaking strength and elongation at break as measured by ASTM D885 of 8.0 to 15.0 g / d and 5 to 15%, respectively, and may be measured according to JIS-L 1017 method of Japanese Standard Association (JSA) The strength retention after the disk fatigue test can be 80% or more.

The hybrid tire cord is characterized in that 3% LASE (Load at Specific Elongation), 5% LASE, and 7% LASE measured by ASTM D885 are 1.0 g / d to 5.0 g / d, 3.0 g / d to 8.0 g / d , And 6.0 g / d to 13.0 g / d.

The hybrid tire cord may have a dry shrinkage of 0.3 to 2.5% measured at 0.01 g / d of initial load for 2 minutes at 180 ° C.

According to another aspect of the present invention, there is provided a method for producing an aramid filament according to the first aspect of the present invention, comprising: a first step of lowering an aramid filament in a first direction to form an aramid kneaded yarn; A second step of lowering the PET filament in a second direction to form a PET bottom yarn, the second step being performed simultaneously with the first step; And a third step of straddling the aramid warp yarn and the PET underfoot yarn together in a third direction to form a cord in the third direction, the third step being performed continuously with the first and second steps; Immersing the furnace cord in an adhesive solution; Drying the furnace cord impregnated with the adhesive solution by the immersion process; And completing the dip code by heat treating the dried furnace cord, wherein the first, second and third steps are performed by one twister, the second direction is the same direction as the first direction Wherein the third direction is opposite to the first direction and the tension applied to the PET filament in the second step is smaller than the tension applied to the aramid filament in the first step. / RTI >

The tensile force applied to the PET filament in the second step is set so that the length of the PET after-warp yarn after the untwisted twist of the upstanding yarn can be 1.005 to 1.050 times the length of the aramid warp yarn, May be smaller than the tension applied to the aramid filament in the first step.

The adhesive solution may include an RFL (Resorcinol Formaldehyde Latex) adhesive or an epoxy adhesive, and the drying step may be performed at 70 to 200 ° C for 30 to 120 seconds, and the heat treatment step may be performed at 30 to 250 ° C The drying step and the heat treatment step may be continuously performed, and the tensile force applied to the furnace cord in the dipping step, the drying step, and the heat treatment step may be 0.4 kg / It can be more than cord.

The length of the aramid lower strand after the untwisting of the upper side of the dipped cord of a predetermined length may be 1 to 1.1 times the length of the lower PET yarn.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the invention as claimed.

According to the present invention, the productivity and the manufacturing cost of the hybrid tire cord can be improved because the upper stage and the lower stage are performed by one twister.

Further, thanks to the high strength of the aramid, the hybrid tire cord of the present invention can minimize tire deformation at high speeds.

In addition, the hybrid tire cord of the present invention can minimize the variation in the physical properties and the defective rate which may be caused in the manufacturing process because the aramide lower warp yarns and PET lower warp yarns have substantially the same twist count and substantially the same length.

In addition, according to the present invention, since the length of the aramid lower warp yarn after untwisting the tire cord is 1 to 1.1 times the length of the PET yarn warp yarn, the stress applied to the tire cord when the tire is tensioned / Not only PET but also PET. As a result, the hybrid tire cord of the present invention having excellent endurance characteristics can maintain the stability of the tire even at high speed traveling for a long time.

Hereinafter, embodiments of the hybrid tire cord and the method of manufacturing the same will be described in detail.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Therefore, the present invention encompasses all changes and modifications that come within the scope of the invention as defined in the appended claims and equivalents thereof.

As used herein, the term " primarily twisted yarn " refers to a single yarn formed by twisting a filament in either direction.

As used herein, the term " plied yarn "refers to a yarn made by twisting together two or more strands of yarn in either direction and is sometimes referred to as a " raw cord ".

The term "tire cord" as used herein refers to a composite yarn containing an adhesive so that it can be directly applied to a rubber product, and is also referred to as a "dip cord ".

As used herein, the term "twist number" means the number of twists per meter, and the unit is a twist per meter (TPM).

In order to develop a high-performance tire cord, the structural aspects such as the physical properties of the material itself, the number of twists, and the shape must be considered.

The tire cord according to the present invention is a hybrid type of PET and aramid, comprising a PET twist yarn in a first twist direction and an aramid yarn twist in a second twist direction, wherein the PET bottom yarn and the aramid bottom yarn together are oriented in a third twist direction It is staged.

The PET filament and the aramid filament are simultaneously inferred by a single twisted yarn (for example, a cable cord twisted yarn) to form the PET lower yarn and the aramid lower yarn, and at the same time And a raw cord is formed. The second twist direction of the aramid lower knit yarn is the same as the first twist direction of the PET lower knit yarn, and the third twist direction (i.e., the upstanding direction) is opposite to the first twist direction.

Since the bottom and top runs are performed by one twister, the productivity of the hybrid tire cord can be improved and the manufacturing cost can be reduced compared to the batch method wherein each bottom and top run is performed using different twisters.

On the other hand, aramid has a linear molecular chain and therefore has a high degree of crystallinity and little heat shrinkage behavior. On the other hand, the PET filament manufactured through the stretching process to develop the high strength and high modulus required in the tire cord is shrunk during the heat treatment process performed in the dip cord manufacturing process. As a result, in the final tire cord, A difference in length of the underlayer occurs, resulting in uneven physical properties. If the shape of the dipped cord becomes uneven due to the shrinkage of PET inferior yarn, the aramid inferior yarn and the PET inferior yarn are separated from each other, resulting in the strength drop and the fatigue performance being also lowered.

Therefore, according to the present invention, in order to produce a hybrid tire cord having high strength and fatigue performance, the tension applied to the aramid filament and the PET filament during the twisting process is adjusted to make the PET yarn longer than the aramid yarn. In addition, a relatively high level of tension can be applied to the cord to minimize shrinkage of the PET underlay during the heat treatment process.

Specifically, the tension applied to the aramid filaments and the PET filaments during the twisting process is appropriately adjusted so that the aramid yarn and the PET yarn are substantially the same in the final tire cord. In other words, the length of the PET underlayer can be made longer than that of the aramid underlayer by applying a relatively larger tension to the aramid filament than the PET filament when the underlayer is performed.

According to the present invention, the length of the PET underlayer after untwisting the upper edge of the roc cord of the predetermined length is 1.005 to 1.050 times the length of the lower aramid yarn. That is, the roc code of the present invention has a merged structure in which the structure under which the aramid bottom yarn is covered by the PET bottom yarn (i.e., the " covering structure ") is slightly added.

Because the length of the PET underlay is longer than the length of the aramid underlay in the rocade of the present invention, the shrinkage of the PET underfill caused by sequential dipping, drying, That is, the deep cord), the length of the aramid lower warp yarn can be prevented from being excessively longer than that of the PET bottom yarn. According to a preferred embodiment of the present invention, the length of the lower aramid yarn after untwisting the upper edge of the final tire cord of a predetermined length is 1 to 1.1 times the length of the lower PET yarn.

If the aramid lower yarn in the tire cord is shorter than the PET underfire (i.e., the length of the PET underfill in the roc cord is greater than 1.050 times the length of the aramid underfill), then the tensile / Since the stress is applied intensively to the aramid kneading yarn, the endurance of the tire cord is inevitably low, and the stability of the tire can not be secured at a high speed for a long time due to the low endothelial characteristic.

On the other hand, when the length of the PET underlayer in the roc cord is less than 1.005 times the length of the aramid lower knit, the tire cord of the covering structure having the length of the aramid lower knit exceeding 1.1 times the length of the PET lower knit is finally obtained. In the tire cord having such a covering structure, since the aramid lower kneading yarn covering the PET yarn is pushed by the friction with the guide or the roller to form a loop, the yarn unevenness is caused, In addition, the tire defect rate increases due to the physical property variation in the tire manufacturing process.

According to the present invention, the same twist number is applied within the range of 200 to 500 TPM when performing the bottom and top run for the rocade manufacture. However, unexpected untwist occurs when the subsequent dipping, drying, and heat treatment processes for applying the adhesive are performed sequentially, resulting in a difference of less than 15% between the initial set twist count and the initial set twist count have. Generally, higher tensile twists of the fibers reduce strength but increase fatigue performance. On the other hand, the lower the twist of the fibers, the stronger the strength, but the fatigue performance decreases.

According to the present invention, since the aramid lower warp yarn and the PET lower yarn have substantially the same twist number, length and structure, the lower warp yarns exhibit similar behavior in strength and fatigue performance.

The aramid filaments and PET filaments used in the production of the hybrid tire cord of the present invention are not particularly limited, but have the same or similar fineness within the range of 400 to 3000 denier.

The aramid contains an amide group and a phenyl ring in the main chain, and is classified into a para-form (p-) and a meta-form (m-) depending on the linkage state of the phenyl ring. According to a preferred embodiment of the present invention, the aramid is poly (p-phenylene terephthalamide).

According to one embodiment of the present invention, the aramid filament has a fineness of 400 to 3000 denier, a tensile strength of 20 g / d or more, and a cut elongation of 3% or more. If the tensile strength of the aramid filament is less than 20 g / d, the low strength of the PET filament can not be compensated sufficiently, so that there is an increased risk that the tire is deformed at high speed.

Since the aramid filament has a modulus of 5 to 10 times the PET filament, even if the weight ratio of the aramid yarn to the PET yarn in the hybrid tire cord is only about 15:85, the aramid filament has a modulus of 2 to 3 times the tire cord of the PET single material. Therefore, the weight ratio between the aramid lower yarn and the PET lower yarn can be determined taking both the physical properties of the tire cord and the manufacturing cost into consideration. According to one embodiment of the present invention, the weight ratio of the aramid lower yarn and the PET lower yarn is 20:80 to 80:20.

If the weight of the PET underlayer exceeds 4 times the weight of the aramid underfire, the finally obtained hybrid tire cord will conform to the physical properties of the PET, resulting in insufficient strength and modulus. To compensate for the lack of strength and modulus, As a result, the weight of the tire can not be reduced.

On the other hand, if the weight of the aramid lower yarn exceeds 4 times the weight of the PET lower yarn, the performance of the hybrid tire cord is deteriorated to the inner skin, so that it is difficult to secure the durability of the tire, and the cost is increased by using a large amount of expensive aramid.

The hybrid tire cord according to an embodiment of the present invention further includes an adhesive coated on the PET under-warp yarn and the aramid warp yarn for improving adhesion with the tire, and the cutting strength and elongation at break measured according to ASTM D885 And 8.0 to 15.0 g / d and 5 to 15%, respectively, and the strength retention after disc fatigue testing according to the JIS-L 1017 method of the Japanese Standard Association (JSA) may be 80% or more. Also, the hybrid tire cord is characterized in that the 3% LASE, 5% LASE, and 7% LASE measured by ASTM D885 are 1.0 g / d to 5.0 g / d, 3.0 g / d to 8.0 g / g / d to 13.0 g / d. The hybrid tire cord may have a dry shrinkage of 0.3 to 2.5% as measured at 0.01 g / d of initial load for 2 minutes at 180 deg.

Hereinafter, the method of manufacturing the hybrid tire cord of the present invention will be described in more detail.

Aramid filaments of 400 to 3000 denier and PET filaments of 400 to 3000 denier are fed into the cable cord twist machine which performs both the lower and upper yarns. In the twisting machine, a first step of lowering the aramid filament in the first direction to form the lower aramid yarn and a second step of lowering the PET filament in the second direction to form the PET lower yarn are simultaneously performed, A third step of straddling the aramid lower warp yarn and the PET lower yarn together in a third direction is performed successively with the first and second steps. As described above, the second direction is the same direction as the first direction, the third direction is the opposite direction to the first direction, and the same direction within the range of 200 to 500 TPM The number of twists is applied.

According to the present invention, since the continuous filament yarn is produced by the continuous method in which the lower yarn and the upper yarn are carried out in one twister, the PET filament and the aramid filament are respectively twisted with different twisters and then bundled with another twister. The productivity of the hybrid tire cord can be improved.

According to the present invention, the tension applied to the PET filament in the second step is smaller than the tension applied to the aramid filament in the first step. Therefore, the length of the aramid lower warp yarn after the twisting of the upper yarn in a predetermined length of rocade may be slightly shorter than the length of the PET lower yarn yarn, even though the lower yarn and the upper yarn are performed by a single twist yarn.

According to an embodiment of the present invention, after the upper edge is untwisted (that is, after untwisting the combined twist yarn) in the rocord of a predetermined length, the length of the PET underfill is 1.005 to 1.050 times the length of the lower aramid yarn The tensile force applied to the PET filament in the second step is smaller than the tensile force applied to the aramid filament in the first step.

The magnitude of the tension applied to the PET filaments and the aramid filaments can be adjusted by appropriately setting the revolutions per minute (rpm) of the rolls of the twister.

Subsequently, the step of immersing the furnace cord in an adhesive solution, drying the furnace cord impregnated with the adhesive solution, and heat treating the dried furnace cord are successively performed, whereby the hybrid tire cord of the present invention , Deep code) is completed.

An RFL solution (Resorcinol Formaldehyde Latex) or an epoxy based adhesive composition liquid may be used as the adhesive solution.

The temperature and time of the drying step may vary depending on the composition of the adhesive solution, but the drying step is usually carried out at 70 to 200 DEG C for 30 to 120 seconds.

The heat treatment may be performed at 200 to 250 ° C for 30 to 120 seconds.

Through the above-described processes, the adhesive component of the adhesive solution is coated on the surface of the rocade, so that the adhesion between the hybrid tire cord of the present invention and the rubber composition for tire production is increased.

On the other hand, although the twisted yarn is set to perform the lower and upper yarns with the same twist number, twist loosening may occur in the process of being dipped in the adhesive solution, dried and heat-treated after the twist yarn produced by the twist yarn have. In order to minimize such twist loosening (for example, to ensure that the difference between the original twist count and the actual twist count of the final tire cord is less than 15% of the original twist count) and to prevent excessive shrinkage of the PET twist twist , It is preferable that the tensile force applied to the furnace cords in the dipping, drying, and heat treating steps performed continuously is 0.4 kg / cord or more per cord.

According to the present invention, it is possible to remarkably reduce the twist failure in the twisting process and to stabilize the combined yarn, so that the variation in physical properties due to unevenness in shape can be minimized. Specifically, in the case of the hybrid tire cords of the present invention manufactured under the same conditions, the difference between the maximum value and the minimum value in each property can be drastically reduced. For example, the difference between the maximum value and the minimum value of the cut strength 3 g / d or less, and the difference between the maximum value and the minimum value of the elongation at break is 5% or less.

Hereinafter, the effects of the present invention will be described with reference to specific examples and comparative examples of the present invention. It should be understood, however, that the following examples are for the purpose of promoting understanding of the present invention and are not intended to limit the scope of the present invention.

Example  One

1000 denier PET filaments and 1000 denier aramid filaments are fed into the cable cord twisted machine to perform 2-ply yarn (i.e., cordierite yarn) in the Z- ). At this time, the cable cord twisted yarn was set at a twist number of 460 TPM for the lower yarn and the upper yarn, and the tension applied to the PET filaments and the aramid filaments was adjusted to increase the length of the PET yarn for the aramid yarn twist yarn Ratio (i.e., the PET underfire length / the aramid underfire length) was 1.005. In order to obtain the ratio of the length between the aramid yarn and the PET yarn, a 1-m long cord sample was applied at a load of 0.05 g / d to separate the aramid yarn and PET yarn from each other. The length of the aramid yarn and the length of the PET yarn And a length of 0.05 g / d.

The rocade was then mixed with 2.0% by weight of resorcinol, 3.2% by weight of formalin (37%), 1.1% by weight of sodium hydroxide (10%), 43.9% by weight of styrene / butadiene / vinylpyridine 15) rubber (41%), and water. The resulting solution was dipped in a resorcinol-formaldehyde-latex (RFL) adhesive solution. The rocade containing the RFL solution by immersion was dried at 150 캜 for 100 seconds and heat treated at 240 캜 for 100 seconds to complete the dip cord. The tensile force applied to the two-phase twist during the immersion, drying, and heat treatment was 0.5 kg / cord.

Example  2

A dip cord was prepared in the same manner as in Example 1, except that the ratio of the length of the PET underlayer to the aramid underfill was 1.010.

Example  3

A dip cord was prepared in the same manner as in Example 1, except that the ratio of the length of the PET bottom yarn to the aramid bottom yarn was 1.020.

Example  4

A dip cord was prepared in the same manner as in Example 1, except that the ratio of the length of the PET underlayer to the aramid yarn in the locator cord was 1.030.

Example  5

A dipped cord was prepared in the same manner as in Example 1, except that the ratio of the length of the PET underlayer to the aramid yarn in the loco cord was 1.050.

Comparative Example  One

The cable cord twisted yarn was set at a twist number of 360 TPM for the lower yarn, and the ratio of the length of the PET lower yarn to the aramid yarn twist yarn in the roc cord was 0.980. In the same manner as in Example 1, Code.

Comparative Example  2

The cable cord twisted yarn was set at a twist number of 400 TPM for the lower edge and the rope cord was cut in the same manner as in Example 1 except that the ratio of the length of the PET bottom yarn to the aramid bottom yarn in the rocade was 0.980 Code.

Comparative Example  3

The cable cord twisted yarn was set at a twist number of 430 TPM for the lower edge and the rope cord was twisted in the same manner as in Example 1 except that the ratio of the length of the PET bottom yarn to the aramid bottom yarn was 0.980 Code.

Comparative Example  4

A dip cord was prepared in the same manner as in Example 1, except that the ratio of the length of the PET lower strand to the aramid lower strand in the cord was 0.980.

The strengths, midtones (at 4.5 kg), spinning, dry heat shrinkage, and disk fatigue properties of the dip cords obtained by the above Examples 1-5 and Comparative Examples 1-4 were measured by the following methods, Respectively.

* strong( kgf ), Chinese cabbage (at 4.5 kg) ( % ), And Omission ( % )

According to the ASTM D-885 test method, the tensile strength of the dip cord, the tensile strength (tensile strength), and the tensile strength were measured by applying a tensile speed of 300 m / min to 10 samples of 250 mm using an Instron tester (Instron Engineering Corp., Canton, Mass) 4.5 kg) and the turnout were measured respectively. Next, the tenacity, tenacity (at 4.5 kg) and turnover were obtained by calculating the tenacity, tenacity (at 4.5 kg), and average of the consecutive ten samples, respectively.

* Dry heat shrinkage ( % )

The test piece was allowed to stand for 24 hours or more under atmospheric conditions of a temperature of 25 DEG C and a relative humidity of 65%, and then measured at 0.01 g / d (20 g) under a second load at 180 DEG C for 2 minutes using a Testrite instrument.

* Disk fatigue characteristics

After the dipped cord having the strength (pre-fatigue strength) measured was vulcanized to rubber to prepare a sample, a disk fatigue tester was used according to JIS-L 1017 method of Japanese Standard Association (JSA) The sample was subjected to fatigue by repeating tensile and shrinkage for 16 hours within a range of 8% while rotating at 80 DEG C at a speed of 2500 rpm. Then, after removing the rubber from the sample, the durability after fatigue was measured. Based on the fatigue pre-stress and post-fatigue strength, the strength retention rate defined by the following formula 1 was calculated.

(1): Strength retention (%) = [Strength after fatigue (kgf) / Strength before fatigue (kgf)] × 100

Here, the pre-fatigue and post-fatigue strength (kgf) was measured at a tensile rate of 300 m / min for a 250 mm sample using an Instron tester (Instron Engineering Corp., Canton, Mass) according to the ASTM D- And the strength of break of the deep cords was measured.

PET Length / Aramid Length
(Raw Cord) strong
(kgf) Chinese (at 4.5kg)
(%) Omission
(%) Dry heat shrinkage
(%) Strong retention rate
(%) Example 1 1.005 24.1 2 9.3 1.02 90.3 Example 2 1.010 25.6 1.9 9.3 1.02 92.5 Example 3 1.020 24.6 2 8.9 0.96 96.4 Example 4 1.030 24.7 1.9 8.9 0.96 98.7 Example 5 1.050 24.2 1.7 7.2 0.89 95.1 Comparative Example 1 0.980 26.3 1.8 7.7 0.85 41.6 Comparative Example 2 0.980 23.6 2.2 8.6 0.8 59.9 Comparative Example 3 0.980 23.5 2.3 9.1 0.88 53.9 Comparative Example 4 0.980 22.6 2.5 13.1 0.87 68.1

Claims (10)

In the hybrid tire cord,
PET underfire;
Aramid Downward; And
A PET underlayer and an adhesive coated on the aramid underfill,
The PET underlayer and the aramid underlayer are laminated together,
Wherein in the hybrid tire cord of a predetermined length, the length of the aramid lower knitted fabric after untwisting of the upper side is 1 to 1.1 times the length of the PET lower knitted fabric,
Hybrid tire cord. The method according to claim 1,
The PET underfill has a first twist direction,
Wherein the aramid lower warp yarns have a second twist direction,
Wherein the PET underlayer and the aramid underlayer are staged together in a third twist direction,
Wherein the second twist direction is the same direction as the first twist direction,
Wherein the third twist direction is opposite to the first twist direction,
Hybrid tire cord. The method according to claim 1,
Wherein the weight ratio of the PET underlayer to the aramid underlay is 20:80 to 80:20,
Hybrid tire cord. The method according to claim 1,
The breaking strength and elongation at break measured by ASTM D885 are 8.0 to 15.0 g / d and 5 to 15%, respectively,
The strength retention after disc fatigue test according to JIS-L 1017 method of Japanese Standard Association (JSA) is 80% or more,
Hybrid tire cord. 5. The method of claim 4,
D to 5.0 g / d, 3.0 g / d to 8.0 g / d, and 6.0 g / d to 13.0 g / d, respectively, measured by ASTM D885 sign,
Hybrid tire cord. 6. The method of claim 5,
And a dry shrinkage of 0.3 to 2.5% as measured at 0.01 g / d of initial load for 2 minutes at < RTI ID = 0.0 > 180 C. &
Hybrid tire cord. A first step of lowering the aramid filament in a first direction to form an aramid kneaded yarn;
A second step of lowering the PET filament in a second direction to form a PET bottom yarn, the second step being performed simultaneously with the first step;
And a third step of straddling the aramid warp yarn and the PET underfoot yarn together in a third direction to form a cord in the third direction, the third step being performed continuously with the first and second steps;
Immersing the furnace cord in an adhesive solution;
Drying the furnace cord impregnated with the adhesive solution by the immersion process; And
And completing the dip code by heat treating the dried rococo,
The first, second and third steps are performed by one twister,
Wherein the second direction is the same direction as the first direction,
The third direction being opposite to the first direction,
Wherein the tension applied to the PET filament in the second step is smaller than the tension applied to the aramid filament in the first step,
A method of manufacturing a hybrid tire cord. 8. The method of claim 7,
The tensile force applied to the PET filament in the second step is set so that the length of the PET after-warp yarn after the untwisted twist of the upstanding yarn can be 1.005 to 1.050 times the length of the aramid warp yarn, Wherein the tension applied to the aramid filament is smaller than the tension applied to the aramid filament in the first step,
A method of manufacturing a hybrid tire cord. 9. The method of claim 8,
Wherein the adhesive solution comprises an RFL (Resorcinol Formaldehyde Latex) adhesive or an epoxy adhesive,
The drying step is carried out at 70 to 200 DEG C for 30 to 120 seconds,
The heat treatment step is performed at 200 to 250 DEG C for 30 to 120 seconds,
The immersion step, the drying step, and the heat treatment step are continuously performed,
In the immersion step, the drying step and the heat treatment step, the tensile force applied to the furnace cord is 0.4 kg / cord or more per cord,
A method of manufacturing a hybrid tire cord. 10. The method of claim 9,
Characterized in that the length of the aramid lower knitted fabric after untwisting of the upper side of the dipped cord of a predetermined length is 1 to 1.1 times the length of the lower PET yarn.
A method of manufacturing a hybrid tire cord.