KR20020009994A - Pneumatic tire with improved durability - Google Patents

Abstract

PURPOSE: A pneumatic tire is provided to improve high-speed traveling performance and to enhance durability by applying a carcass ply including a nylon 46 cord. CONSTITUTION: A carcass ply is manufactured by using a nylon 46 cord constituted of 100-6000 denier ply. The nylon 46 cord has excellent thermal stability, structural stability, adhesiveness, and heat resistance. The carcass ply is placed at the innermost portion of a tire. Thus, high thermal stability improves the durability. High adhesiveness enhances a resistance against tread and belt separation during a high-speed travel. According to the improved structural stability, the deformation of a tire during a curing process is restrained. High contractile force prevents a belt from displacing due to the centrifugal force during a high-speed travel.

Description

Pneumatic tire with improved durability {PNEUMATIC TIRE WITH IMPROVED DURABILITY}

The present invention relates to a pneumatic tire having improved durability, and more particularly, to a pneumatic tire having improved durability applied to a carcass ply including a nylon 46 cord.

In recent years, high speed driving stability and high durability of the tire are also very important due to high-speed driving in accordance with the luxury of passenger cars, and in particular, tires having an ultra-low flat ratio such as racing tires are becoming more important.

In the case of ultra-high speed tire carcasses, such as racing tires, adhesion and thermal stability are very important properties. Accordingly, the conventional carcass cord adopts a nylon 66 cord having such excellent performance.

However, the conventional tires applied with nylon 66 had poor driving performance and were not satisfactory in durability.

The present invention has been made in order to improve the above problems, the pneumatic inlet improves the high-speed driving performance and durability performance of the tire by using a material excellent in thermal stability, structural stability, adhesive properties as the material of the carcass cord It is an object to provide a tire.

The pneumatic tire of the present invention is characterized by applying a carcass ply including a nylon 46 cord composed of 1000 to 6000 denia plies.

That is, the pneumatic tire of the present invention is applied to nylon 46 having excellent thermal stability, structural stability, adhesive performance, high temperature resistance characteristics compared to the conventional carcass ply material nylon 66 to satisfy the high-speed driving performance of passenger car tires It is characterized by improving durability.

The nylon 46 has the following excellent properties compared to nylon 66 applied to the existing carcass ply.

First, the thermal stability is superior to nylon 66 as shown in Table 1 below.

Table 1

Nylon 66 Nylon 46 Melting temperature (℃) 260 290 Glass transition temperature (℃) 80 70

The superior thermal stability is characterized by the fact that in the case of a tire for a passenger car, the internal temperature of the tire increases significantly during high-speed driving. Especially, the carcass ply part is located at the innermost part of the tire. Among the required properties, thermal stability is very important.

Second, the adhesive performance is excellent.

The structure of nylon 46 and nylon 66 is as follows.

Nylon 66: H- (HN- (CH ₂ ) ₄ -NH-CO- (CH ₂ ) ₆ ) CO) _n -OH

Nylon 46: H- (HN- (CH ₂ ) ₄ -NH-CO- (CH ₂ ) ₄ ) CO) _n -OH

As described above, nylon 46 has a lower unit molecular weight and more amide groups capable of forming a chemical bond with an adhesive per same molecular weight than nylon 66. As a result of adhesion by H-test, as shown in Table 2 below. It is advantageous for adhesion.

TABLE 2

Nylon 66 Nylon 46 Initial Adhesion (kgf) 14.5 15.8 105 ℃, after aging for 24 hours 13.5 15.2 105 ℃, 72 hours after aging 10.6 13.2 105 ℃, after aging 120 hours 8.2 11.5

This improvement in adhesion is a very important item in the case of carcass ply to improve the resistance to tread and belt separation (separation) at high speeds.

Third, the shrinkage rate is low (excellent structural stability).

Nylon 46 has a smaller shrinkage as shown in Table 3 due to excellent molecular orientation compared to nylon 66.

TABLE 3

Nylon 66 Nylon 46 Shrinkage (%) 160 ℃, 15 minutes 3% One%

Such a low shrinkage rate is advantageous because it can reduce the tire deformation caused by the shrinkage of the cord when the tire is vulcanized.

Fourth, the contractile force is large.

As shown in Table 4, nylon 46 has a larger shrinkage than nylon 66. Such physical properties are advantageous because the carcass ply cord can support the force that the belt tries to disengage due to the centrifugal force during the high speed driving of a passenger car tire.

Table 4

Nylon 66 Nylon 46 Shrinkage (%) 120 ° C mN / ex. 1.5 2.5

Therefore, by applying the nylon 46 having the above advantages can improve the high-speed driving performance and durability performance of the tire, carcass comprising a nylon 46 cord consisting of 1000 to 6000 denia ply to achieve the desired effect of the present invention The use of plies is preferred, especially in passenger car tires, particularly in the 55 series and below (eg 55, 50, 45, 40 ...).

Hereinafter, the present invention will be described in more detail with reference to the following Examples and Comparative Examples. The following examples are merely examples for illustrating the present invention and do not limit the protection scope of the present invention.

Examples and Comparative Examples

A tire was applied to a carcass ply including nylon 66 (comparative example) and nylon 46 (example) having the same structure with a 1260D / 2p structure, and was endured by ECER 30 test, a general test for evaluating the speed durability performance of the tire. The performance was measured and the results are shown in Table 5 (standard: 225/45 R15, 1260D / 2p) and Table 6 (standard: 225/40 R17, 1260D / 2P).

Table 5

Comparative example (nylon 66) Example (nylon 46) Carcass fly number Carcass Fly 2 pieces Carcass Fly 2 pieces Code Array Density (ends / inch) 31 31 High speed driving evaluation (ECER 30) 1 hour 50 minutes 2 hours 10 minutes

Table 6

Comparative example (nylon 66) Example (nylon 46) Carcass fly number Carcass Fly 2 pieces Carcass Fly 2 pieces Code Array Density (ends / inch) 28 28 High speed driving evaluation (ECER 30) 1 hour 42 minutes 2 hours 12 minutes

As can be seen from the above, the pneumatic tire to which the carcass ply according to the present invention is applied is improved in high-speed driving performance compared to the conventional pneumatic tire to which nylon 66 is applied, and the durability is very excellent.

Claims (1)

A pneumatic tire for a passenger car, characterized by applying a carcass ply containing a nylon 46 cord composed of 1000 to 6000 denia plies.