KR100476241B1 - Nylon cord for tire reinforced belt cord and pneumatic tire using thereof - Google Patents

Abstract

The present invention relates to a nylon cord for a tire reinforcing belt cord and a pneumatic tire for a passenger car using the same, wherein the nylon cord reinforced with 0.1 to 4.0 parts by weight of nano clay modified with nylon has excellent modulus, strength, and glass transition temperature. The nylon cord thus manufactured was applied to the reinforcing belt cord to manufacture pneumatic tires for passenger cars, which resulted in the improvement of driving stability at high speed and at low speed and at high speed.

Description

Nylon cord for tire reinforced belt cord and pneumatic tire using girls

The present invention relates to a nylon cord for a tire reinforcing belt cord reinforced with a nano clay modified with nylon, and a pneumatic tire for a passenger car using the same as a reinforcing belt, and more particularly, to a nanoclay made of nylon during nylon cord manufacture. By manufacturing a nylon cord, and manufacturing a pneumatic tire for a passenger car applied to the reinforcement belt to improve the low-speed and high-speed driving performance at the same time.

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 such a reinforcing belt cord is heat resistance adhesion, shrinkage, modulus retention at room temperature and high temperature. Among these, 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. .

In addition, modulus is generally a physical property highly correlated with ride comfort, steering stability, and the like. In other words, a tire cord with a large modulus plays an advantageous role in reducing the change in the shape of the belt due to the force transmitted from the outside, and the shape maintenance from the external force can maintain the performance of the originally designed tire. affect.

Another factor that can affect the running performance of the tire is the heat generated when the tire is running. In general, all materials decrease in modulus with increasing temperature. The modulus of the reinforcement belt also decreases as the tire's running speed increases as the internal temperature increases.As the decrease in modulus at high temperatures leads to the deterioration of tire performance at high temperatures, it is very important to maintain the modulus at high temperatures. It can be said to be a required characteristic of.

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.

 On the other hand, it is known that the addition of reinforcing agents such as clay to the polymer increases the modulus, strength, and glass transition temperature.

However, when ordinary clay (diameter 8 µm) is added to nylon, since nylon is composed of 25 µm thin filaments, the added clay acts as a scratch rather than as a reinforcing agent, and thus adversely affects strength. Using clay in code was not possible.

Therefore, the present inventors while trying to solve the above problems when using a nylon cord as a reinforcing belt, during the nylon cord polymerization to manufacture a nylon cord by reinforcing the nanoclay modified with nylon and apply it to the reinforcing belt As a result of manufacturing a pneumatic tire, the present invention has been found to be able to improve the low-speed and high-speed running performance simultaneously by improving the heat resistance and improving the modulus at room temperature and the decrease in modulus at high temperature. .

Accordingly, an object of the present invention is to provide a nylon cord for a tire reinforcing belt cord having excellent heat resistance, high modulus at room temperature and high temperature, and excellent low speed and high speed running performance.

In addition, the object of the present invention is to provide a pneumatic tire for a passenger car which is excellent in driving stability at high speed, durability at low speed and high speed by applying such a nylon cord to a reinforcing belt cord.

Nylon cord for a tire reinforcing belt cord of the present invention for achieving the above object contains 0.1 to 4.0 parts by weight with respect to 100 parts by weight of nylon nanomodified with nylon for the cord, using a reinforcement belt cord using the same It is characterized by being a pneumatic tire.

The present invention will be described in more detail as follows.

The present invention relates to a nylon cord for a tire reinforcing belt cord modified with nylon and a pneumatic tire for a passenger car using the same.

The nylon cord of the present invention is prepared by adding a nanoclay modified with nylon in the polymerization or spinning process of the cord.

Nylon used in the present invention may be nylon 6, nylon 66 or nylon 46 and the like. The nanoclay modified with nylon is montmontmorillonite dispersed in nylon 6, and in the present invention, nanocore 1.24T is used. Specifically, montmorillonite is a form in which multiple platelets are stacked, and sodium cations (Na ⁺ ) are present between layers. The montmorillonite having such a structure is applied to a polymer to prepare a polymer nanocomposite, which is used to prepare a nanocomposite. Increase the interlayer spacing of montmorillonite. (So called intercalation). Nanocore's nanomer 1.24T used in the present invention was obtained by infiltrating a nylon monomer between the montmorillonite plates and polymerizing in the intercalation process. The nanoclay is a type of nanoclay in which the spacing of plates becomes wider as the molecular weight of nylon increases, specifically, the thickness of the individual plate structures is 1 to 3 nm, the aspect ratio is 200 to 500, and the width of the plate is about 100 to 1000 nm. It is This is schematically shown in FIG.

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When the nylon-modified nanoclay is added at the time of polymerization or spinning of nylon, the clay is dispersed to a small size of several nm level as shown in FIG. 2, and serves as a reinforcing agent to sufficiently modulate the modulus, strength, and glass transition. The result is that the temperature rises. It is preferable to add 0.1 to 4.0 parts by weight of the nanoclay modified with nylon, which plays such a role, based on 100 parts by weight of the total nylon. If the added amount is less than 0.1 parts by weight, it is difficult to achieve the desired modulus, strength and glass transition temperature, and if it exceeds 4.0 parts by weight, the elongation at break of the cord decreases rapidly, making it difficult to use the reinforcing belt. .

When the nylon cord for the reinforcing belt is manufactured using the nanoclay modified with such nylon, it can be added during the polymerization or spinning of the nylon cord. For example, first, the caprolactam and the nanoclay modified with nylon are combined together in the polymerization process. It is added and polymerized. The polymerized chips are spun and then stretched, twisted, rewoven and heat treated under the same conditions as in conventional nylon cord manufacture.

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Next, a tire in which the nylon cord thus prepared is applied to the reinforcing belt is manufactured.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Examples 1-2 and Comparative Examples 1-2

Next, as shown in Table 1, the polymerization was carried out by adding a nanomer, 1.24T (manufactured by Nanocore), a nanoclay modified with caprolactam and nylon in a polymerization process. The prepared chips were spun under the same level of relative viscosity, and the drawing, twisting, weaving and heat treatment were carried out under the same conditions as in the conventional nylon cord production.

The physical properties of the nylon cord for the reinforcing belt thus obtained was evaluated as follows, and the results are shown in Table 2 below.

Unit: parts by weight Example Comparative example One 2 One 2 Nylon 6 100 100 100 100 Nylon Clay Modified One 2 - 5

Property evaluation

(1) dynamic glass transition temperature

The dynamic glass transition temperature was measured in a dynamic state given a stress and frequency. In this test, the Thermo-Dynamic Mechanic Analyzer (TDMA) was used under a condition of 0.075g / denier load and 1Hz frequency. It was measured by.

(2) 5% modulus

 5% modulus is a value indicating the physical properties according to the tensile strength of the specimen, and refers to the modulus when a certain specimen is stretched 5% of its original length when the specimen is stretched.

(3) breaking strength

The cord is divided by the quantitative fineness divided by the force applied when fracture occurs during elongation test. The test method is according to ASTM D2256.

(4) elongation at break

The elongation at which fracture occurs when the cord is stretched, and the test method is in accordance with ASTM D2256.

(5) heat resistance

 Adhesion specimens and test methods were in accordance with H-test ASTM D4776, and the adhesion was measured after 4 hours of aging at 180 ° C in relation to heat resistance.

Example Comparative Example 1 One 2 One 2 Dynamic glass transition temperature (℃) 123 126 90 126 5% modulus retention (g / D) Room temperature 1.4 1.8 1.1 2.2 120 ℃ 1.1 1.5 0.7 2.0 Breaking strength (g / D) 9.5 11.2 8.3 7.9 Elongation at break (%) 15.3 11.5 21.0 3.4 Heat adhesive force (kg) 14.1 13.7 13.8 13.7

In the results of Table 2, the 5% modulus retention at room temperature and 120 ° C., which is closely related to the steering stability, was found to be excellent when the nylon modified with the nylon of the present invention was added during the nylon cord polymerization, and the same nylon was used. The heat resistant adhesive strength related to the durability of the nylon cord of the present invention manufactured as a basis shows an equivalent level of heat resistant adhesive strength.

Application Examples 1-2 and Application Comparative Examples 1-2

According to the following Table 3, a tire having a general nylon cord having the same structure as that of the nanoclay modified with nylon prepared in Example 2 and having the same structure as 840 D / 2 was prepared.

Application example 1 Application example 2 Application Example 1 Application Example 2 Tire specification 205 / 55R16 215 / 45ZR17 205 / 55R16 215 / 45ZR17 Nylon cord Example 2 Example 2 Comparative Example 1 Comparative Example 1 Fiber structure 840 D / 2 840 D / 2 840 D / 2 840 D / 2 Number of Reinforced Belt Layers One 2 One 2 Reinforcement belt form Full cover Full cover Full cover Full cover Code array density (ends / inch) 35 35 35 35

The high-speed driving durability evaluation (ECER 30), the initial steering stability evaluation, the evaluation of the driving stability after the high-speed driving was performed as follows, and the results are shown in Table 4 below.

(1) High speed driving durability evaluation (ECER 30)

 It evaluated based on ECER 30 which is a high speed driving durability test method.

(2) Evaluation of initial steering stability

 A vehicle equipped with tires required for evaluation is adjusted by a professional experiment driver who can detect changes in steering stability, and grasp the degree of stability of the steering. Here, the initial steering stability is a measure of the adjustment stability of the initial tire mounting.

 (3) Evaluation of driving stability after high speed driving

The evaluation of driving stability after high-speed driving is a measure of the steering stability with the tires warmed up after 30 minutes of running the evaluation tire at 160 km / hr.

Application example 1 Application example 2 Application Example 1 Application Example 2 High speed driving durability (ECER 30) 2 hours 9 minutes 2 hours 23 minutes 1 hour 53 minutes 2 hours 9 minutes Steering Stability (Initial) 115 120 100 100 Steering Stability (After High Speed Driving) 100 105 75 80 Initial tire diameter 99 99 100 100 Tire diameter at high speeds (200 km) 101 100 104 103

As shown in the results of Table 4, Application Examples 1 and 2 in which the reinforcement belt cords reinforced with nylon-modified nanoclay are applied to tires are excellent in high-speed driving durability, low-speed and high-speed driving, Tires with nylon cords of reinforcing belt cords show high driving speed durability, and poor steering stability at low speeds and high speed driving.

As described in detail above, the nylon cord reinforced with nanoclay modified with nylon according to the present invention has excellent modulus, strength, and glass transition temperature, and the tire obtained by applying the nylon cord thus manufactured to the reinforcing belt cord has a high speed. The result is excellent driving durability, steering stability in low speed and high speed driving.

1 shows a nanoclay modified with a polymer,

Figure 2 shows the form in which the nanoclay is dispersed in the nylon cord polymerization or spinning process.

Claims (5)

In the nylon cord for a tire reinforcement belt cord, Nylon cord for the tire reinforcing belt cord, characterized in that containing 0.1 to 4.0 parts by weight of nanoclay modified with respect to 100 parts by weight of nylon. The nylon cord for a tire reinforcing belt cord according to claim 1, wherein the nanoclay modified with nylon is added during nylon cord polymerization or spinning. The nylon cord for a tire reinforcing belt cord according to claim 1, wherein the nylon is selected from nylon 6, nylon 66, and nylon 46. A pneumatic tire for a passenger car in which the nylon cord of claim 1 is applied as a reinforcing belt cord. (New) The method according to claim 1, wherein the nanoclay modified with nylon is montmorillonite having a thickness of 1 to 3 nm, an aspect ratio of 200 to 500, and a plate width of 100 to 1000 nm. Nylon cord for tire reinforcement belt cord.