KR20110061110A - Triple hybrid cord for tire reinforcing belt and air injection tire comprising the same - Google Patents

Abstract

PURPOSE: A triple hybrid cord for a tire reinforcing belt and a pneumatic tire comprising the same are provided to ensure size stability according to the temperature and to improve durability. CONSTITUTION: A triple hybrid cord for a tire reinforcing belt comprises a high elongation cord, a middle elongation cord, and a low elongation cord. The conditioned size of the high elongation cord is 800-2500 D/1. The twist of primary twist and secondary twist of the high elongation cord is 15-35T/dm. The conditioned size of the middle elongation cord is 800-2500 D/1. The twist of primary twist and secondary twist of the middle elongation cord is 15-35T/dm. The conditioned size of the low elongation cord is 800-2500 D/1. The twist of primary twist and secondary twist of the low elongation cord is 15-35T/dm.

Description

Triple Hybrid Cord for Tire Reinforcing Belt and Air Injection Tire Comprising The Same}

Embodiments of the present invention relate to a hybrid cord for a tire reinforcement belt and a pneumatic tire comprising the same.

In a tire, a belt is a very important factor that distributes the stress transmitted from the ground while driving and maintains the tire's grounding shape so that it has excellent driving, wear and braking performance. Particularly, the reinforcing belt catches the flow of the belt and maintains the optimum belt shape when the tire is running, so that the tire always maintains a good belt shape and has good tire performance. The main characteristics required for these reinforcement belt cords are heat resistance, shrinkage, modulus at room temperature and high temperature.

Among them, the heat-resisting adhesive force is the property that is most related to the durability of the tire because it is located between the tread and the belt that generate the most heat in the tire due to the nature of the position where the reinforcing belt is used, and is subject to aging due to high temperature during driving. have.

Tire running and comfort are required items at the same time, but it is very difficult to satisfy two opposing properties at the same time. Nylon 66 cord, a conventional material for high-performance pneumatic tire reinforcement belts, has excellent performance in terms of ride comfort and noise, but has high speed durability and steering stability. In addition, in order to improve high speed durability and steering stability, high modulus reinforcement belt should be adopted to prevent deformation of steel belt and tire due to centrifugal force generated during high speed driving.In this aspect, high modulus polyamide, aromatic polyester, It is preferable to apply a code such as a regenerated cellulose system.

In general, widely used cords for passenger car tires include rayon, polyethylene terephthalate (PET) and nylon. The PET cord is disadvantageous in the heat-resistant adhesive force and the modulus decrease at high temperature is difficult to use as a reinforcing belt. In addition, there is no shrinkage-related behavior in the case of rayon, and it is difficult to use the cord because it does not hold the belt due to the length of the cord rather at a high temperature. Finally, the most widely used nylon currently uses nylon 66, which is more excellent in heat resistance than nylon 6, and nylon 66 is excellent in heat-adhesive resistance and has low modulus at high temperatures compared to PET or nylon 6. It is a small reinforcement belt material that is used the world most. However, due to the nature of nylon, the basic modulus is very low, there is some limitation in terms of improved steering stability.

Embodiments of the present invention provide a triple hybrid cord that maintains dimensional stability with temperature, and has excellent ride comfort, and improved durability and steering stability at low, medium and high speeds.

Embodiments of the present invention provide a pneumatic tire that is excellent in performance and ride comfort at low speed, medium speed, and high speed by maintaining a modulus suitable for driving conditions.

One aspect of the invention consists of a high elongation cord, an elongation cord and a low elongation cord having different cutting strengths, wherein the twist of the upper and lower edges of each of the high elongation cord, medium elongation cord and low elongation cord is 15 It relates to a triple hybrid cord for tire reinforcement belt of from 35T / dm.

Another aspect of the invention relates to a pneumatic tire comprising the triple hybrid cord.

Hybrid cord for tire reinforcement belt and pneumatic tire using the same according to the embodiments of the present invention has excellent heat-resistant adhesive strength, dimensional stability according to temperature is excellent, riding comfort, durability performance and steering at low speed, medium speed and high speed Stability can be improved at the same time.

Hereinafter, the embodiments of the present invention will be described in more detail.

Triple hybrid cord according to an embodiment of the present invention is composed of a high elongation code, a medium elongation code and a low elongation code, they are made of a code having different elongation and strength in the code twisting process. To this end, the twist of the upper and lower ends of each cord of the triple hybrid cord is 15 to 35 T / dm.

In addition, the breaking strength of the triple hybrid cord is 40 kgf or more, the breaking elongation is less than 10%, and the arrangement density of each of the high elongation cord, the medium elongation cord and the low elongation cord may be 17 to 26 EPI.

 Meanwhile, the quantitative fineness of each of the high elongation code, the middle elongation code, and the low elongation code may be 800 D / 1 to 2500 D / 1.

The high elongation cord included in the triple hybrid cord according to the embodiment of the present invention is not necessarily limited thereto, and nylon 6 or nylon 66 may be used.

The neutral elongation code included in the triple hybrid cord according to the embodiment of the present invention may be any one of polyester, polyvinyl alcohol (PVA), rayon, lyocell, and polyethylene naphthalate (PEN). It is not limited.

Low elongation cords included in triple hybrid cords according to one embodiment of the present invention are PK fibers, aramid (aramid) fibers, poly (p-phenylene-2,6-benzobisoxazole) (poly (p-phenylene- 2,6-benzobisoxazole) (PBO) may be any one of fibers, carbon fibers, glass fibers, but is not necessarily limited thereto.

The preferred tensile strength of the triple hybrid cord according to one embodiment of the present invention is 760 to 2040 kgf / in.

Another embodiment of the present invention relates to a pneumatic tire including the triple hybrid cord for the tire reinforcing belt.

The pneumatic tire including the triple hybrid cord for the tire reinforcing belt according to the embodiment of the present invention has excellent heat resistance, and improves dimensional stability according to temperature and improves a problem of deterioration, as well as excellent riding comfort, low speed, Durability and steering stability at medium speed and high speed can be improved simultaneously.

A schematic process of the method of manufacturing a triple hybrid cord for a tire reinforcement belt according to an embodiment of the present invention is as follows.

First, a high elongation cord, a low elongation cord and a low elongation cord yarn are manufactured in separate processes, respectively, and then a high elongation cord drawn yarn, a medium elongation cord drawn yarn, and a low elongation cord drawn yarn are manufactured in a tire cord twisting process.

There is a two-stage twisting method for twisting the lower stage and twisting the upper stage in two stages, and a one-step manufacturing method for manufacturing the upper and lower edges in the same machine at the same time. It is possible to increase the number of twists during the 1st stage of induction work, and in case of applying the 1st stage method, it is manufactured by processing the difference between the upper and lower edges by using another injector before the injector.

The continuous hybrid method of the triple hybrid code according to the embodiments of the present invention may be applied to either a one-step method or a two-step method.

Hereinafter, the configuration and effects of the present invention will be described in more detail with specific examples, but these examples are only intended to more clearly understand the present invention and are not intended to limit the scope of the present invention.

Example  1 ~ 2: triple hybrid  Manufacture of cord

Aramid, polyethylenenaphthalate and nylon 66 were twisted and served and heat treated under conditions similar to conventional nylon cord preparation to produce triple hybrid cords. The type, structure, upper / lower twist of each cord, middle elongation, cutting strength, elongation at break and heat adhesive strength of each cord are shown in Table 1 below.

Comparative example  One: triple hybrid  Manufacture of cord

Triple hybrid cords were prepared by twisting nylon 66 and serving and heat treating under conditions similar to conventional nylon cord manufacture. The type, structure, upper / lower twist of each cord, middle elongation, cutting strength, elongation at break and heat adhesive strength of each cord are shown in Table 1 below.

Comparative example  2: triple hybrid  Manufacture of cord

Aramid, nylon 66 was twisted and served and heat treated under conditions similar to conventional nylon cord preparation to make triple hybrid cords. The type, structure, upper / lower twist of each cord, middle elongation, cutting strength, elongation at break and heat adhesive strength of each cord are shown in Table 1 below.

Table 1

Property evaluation

(1) cutting strong

The force of the cord when the fracture occurs in the elongation test is divided by the quantitative fineness, and the test method is in accordance with ASTM D885.

(2) cutting elongation

The elongation at which fracture occurs when the cord is stretched and the test method is in accordance with ASTM D885.

(3) cord preparation constant temperature and humidity conditions

 It was carried out according to the ASTM 1776 conditions.

(4) heat-resistant adhesion

Adhesion specimens and test methods were in accordance with H-test ASTM D4776 and the adhesion was measured after aging for 24 hours at 100 ° C in relation to heat resistance.

Referring to Table 1, it was shown that the triple hybrid cords have better thermal stability than the conventional nylon 66 cords and hybrid cords at room temperature and 150 ° C, which are closely related to the steering stability. It can be seen that they are equivalent. The dimensional stability of the cord was most disadvantageous to nylon 66.

In addition, the pneumatic tire was manufactured in the configuration as shown in Table 2 by applying the code according to the above Examples and Comparative Examples.

[Table 2]

      The high-speed driving durability evaluation and initial steering stability evaluation of the tire manufactured in the configuration as shown in Table 2, the evaluation of the driving stability after high-speed driving was performed as follows, and the results are shown in Table 3 below.

[Table 3]

Referring to Table 3, Examples 1 and 2 to which the triple hybrid cord is applied are superior to the high-speed running durability nylon 66, it can be seen that the equivalent level compared to the conventional aramid and nylon hybrid cord. In addition, the driver's comfort (noise, ride) at low and high speeds with high speed durability and steering stability was superior to the triple hybrid cord. The most favorable evaluation was made for Example 2, which gave PEN lower twist twist of 28 T / dm at the rolling resistance value. Nylon 66 had the most comfort and noise, but the high speed durability, steering stability and rolling resistance were the most unfavorable.

Although the present invention has been described in detail with reference to preferred embodiments of the present invention, it will be apparent to those skilled in the art that the present invention may be variously changed or modified without departing from the spirit and scope of the present invention. Modifications and variations are also to be construed as being included in the scope of protection of the present invention.

Claims (9)

It is composed of a high elongation cord, an elongation code and a low elongation code having different cutting strength, the twist of the upper and lower edges of each of the high elongation code, elongation code and low elongation code is 15 to 35T / dm Triple hybrid cord for tire reinforcement belts. The triple hybrid cord of claim 1, wherein the cutting force of the triple hybrid cord is 40 kgf or more. The triple hybrid cord of claim 1, wherein the elongation at break of the triple hybrid cord is less than 10%. The triple hybrid cord of claim 1, wherein the arrangement density of the high elongation cord, the medium elongation cord, and the low elongation cord is 17 to 26 EPI, respectively. The triple hybrid cord of claim 1, wherein the quantitative fineness of the high elongation cord, the medium elongation cord, and the low elongation cord is 800 D / 1 to 2500 D / 1, respectively. The triple hybrid cord of claim 1, wherein the tensile strength of the triple hybrid cord is 760 to 2040 kgf / in. The method of claim 1, wherein the high elongation cord is at least one selected from the group consisting of nylon 6, nylon 66, the neutral elongation cord is polyester, polyvinyl alcohol (PVA), rayon, lyocell, polyethylene or At least one selected from the group consisting of phthalates (PEN), wherein the low elongation code is PK fiber, aramid fiber, poly (p-phenylene-2,6-benzobisoxazole) (poly (p-phenylene) -2,6-benzobisoxazole) (PBO) Triple hybrid cord for tire reinforcing belts, characterized in that at least one selected from the group consisting of fibers, carbon fibers, glass fibers. 8. The triple hybrid cord of claim 7, wherein the high elongation cord is nylon 66, the medium elongation cord is polyethylene naphthalate (PEN), and the low elongation cord is aramid fiber. A pneumatic tire comprising a triple hybrid cord for a tire reinforcing belt according to any one of claims 1 to 8.