KR20050001114A - Pneumeric tire with PEN-Lyocell matrix capply cord - Google Patents

Abstract

PURPOSE: A tire capply cord made of polyethylene naphthalate-lyocell is provided to improve durable performance rather than a tire capply using N(Nylon)-66 by using polyethylene naphthalate-lyocell conjugate fibers consisting of polyethylene naphthalate with excellent structural stability and lyocell with good adhesive property and structural stability. CONSTITUTION: A tire capply cord is composed of conjugate fibers made of polyethylene naphthalate and lyocell that are in the rate of 1:1¯2 or 1¯2:1. The TPI(Twist Per Inch) of the conjugate fiber is 10¯80. The EPI(Ends Per Inch) of the tire capply cord is 10¯45. The polyethylene naphthalate or lyocell is 300¯2000 denia. If the number of fibers comprising the cord is over three, the polyethylene naphthalate or lyocell is below 500 denia, or below 10TPI, the physical property and practicality of the tire capply cord are reduced.

Description

Pneumeric tire with PEN-Lyocell matrix capply cord

The present invention relates to a tire cap fly cord composed of a composite fiber of polyethylene naphthalate (PEN) -lyocell.

Recently, high-speed driving is frequently performed according to the luxury of passenger cars and the development of roads, and thus high-speed driving stability and durability of tires are very important. In particular, in the tire having a low flat ratio, the performance is more important, and in order to satisfy such performance, nylon 66 (hereinafter referred to as 'N-66 cord') is frequently applied as a cap fly material.

The N-66 cord has high strength among the fiber cords for tires, and has excellent adhesion and thermal stability. However, conventional tires in which the N-66 cord is applied to a cap ply are not suitable for high speed travel.

The present invention has been made to solve the above problems, the polyethylene naphthalate with excellent structural stability and durability and lyocell with excellent adhesion and structural stability to each other twisted to form a composite fiber cord cord for this It aims at improving the durability of a tire by using it.

In order to achieve the above object, the cord for the tire cap fly of the present invention is polyethylene naphthalate (PEN): lyocell (Lyocell) in a ratio of 1: 1 to 2 to 1-2: 1 twist per inch (TPI) ) Is composed of a composite fiber of 10 to 80, has a 10 to 45 code array density (Ends Per Inch, EPI), the polyethylene naphthalate or lyocell is characterized in that 300 to 2000 denia (denia).

In the above polyethylene naphthalate: when lyocell is composed of a composite fiber, the reason for using 1 or 2 lyocell per polyethylene naphthalate or 1 to 2 polyethylene naphthalate per lyocell is used to construct the cord. If the number of fibers is more than three, the structure is complicated, and the physical properties may drop. If the thickness of the cord is too thick, it is not practical because three fibers constituting the cord is suitable.

In addition, when polyethylene naphthalate or lyocell is used less than 500 denia (denia), the number of tire cords is too small and the cord strength is too low, which causes problems in practical use. When using more than (denia) the thickness of the cord is too thick to increase the weight of the tire, so polyethylene naphthalate or lyocell is recommended to use between 300 to 2000 denia (denia).

On the other hand, polyethylene naphthalate: If the twist per inch (TPI) of lyocell is less than 10, there is a problem of maintaining the straightness of the cord and the fatigue property. Because of the sharp drop problem, the twist per inch (TPI) of polyethylene naphthalate and lyocell is 10 to 80 is best.

In addition, in the present invention, the arrangement density of the capply cord is applied to various numerical ranges. The arrangement density of the capply cord in the present invention is excellent because the physical properties of the cord are excellent when the arrangement density is 10 to 45EPI, which is suitable for the purpose of the present invention. Should be set to 10 ~ 45EPI.

Table 1 compares the code physical properties used in the prior art and the present invention.

<Table 1> Code Property Comparison by Material

Item N-66 PEN Lyocell Strength (g / d) 9.0-10.0 7.0 to 8.0 5.0 to 6.0 Modulus of elasticity (GPa) 50 9.0-15.0 8.5-10.0 Heat Shrinkage (%) (177 ° C × 2min, 0.01g / d) 4.5 to 5.5 0.2 to 1.0 1.8

Looking at the physical properties of the cord material applied to the cap ply according to the present invention and the prior invention with reference to Table 1 as follows.

First of all, the molecular structure of PEN, which can be represented by the following structural formula, is based on a polyester group, and has two benzene groups, which are highly stable in terms of structural stability due to heat and tension. Very disadvantageous for adhesion.

In the above structural formula n is determined according to the molecular weight of PEN, in the present invention n may be used having a degree of polymerization of 5 to 30.

On the other hand, the lyocell cord has a very favorable structure for adhesion due to its good adhesion property with rubber, and also has excellent structural stability due to heat and tension.

Therefore, when the PEN-lyocell composite fiber cord composed of PEN with excellent structural stability and lyocell cord with excellent adhesion and structural stability is applied to a tire cap ply, the weak adhesive force, which is a disadvantage of PEN, can be secured, thereby improving structural stability. In addition, vulnerabilities of moisture, which is a disadvantage of the N-66 code, can be compensated with lyocells.

PEN and lyocell composite cords have better structural stability (larger modulus) and strength than N-66 cords alone, improving tire durability.

Hereinafter, the present invention will be described by the following comparative examples, examples and test examples. However, these do not limit the technical scope of the present invention.

Comparative Example 1

Two 1260 Denia N-66 were twisted to have a twist number of 28 and an array density of 28 EPI to prepare a code ply code 1260D / 2D N-66. One sheet of N-66 was applied to a cap ply of a passenger car tire 235 / 85R 16 standard to measure the strength, the median elongation, and the heat shrinkage. The results are summarized in Table 2 below.

Comparative Example 2

Two 1260 Denia N-66 were twisted to have a twist number of 28 and an array density of 28 EPI to prepare a code ply code 1260D / 2D N-66. The two sheets of N-66 were applied to a cap ply of the passenger car tire 235 / 40R 17 standard to measure the strength, the median elongation, and the heat shrinkage. The results are summarized in Table 3 below.

<Example 1>

The 1000D-1000D composite cord for cap ply was prepared by twisting 1000 denia polyethylenenaphthalate (poly (ethylene 2,6-naphthallene dicarboxylate) and 1000 denia lyocell to have a twist number of 46 and an array density of 24EPI. Jang was applied to the cap ply of the passenger car tire 235 / 85R 16 standard to measure the strength, the median elongation, and the heat shrinkage, and the results are summarized in Table 2 below.

<Example 2>

The 1000D-1000D composite cord for cap ply was prepared by twisting 1000 denia polyethylenenaphthalate and 1000 denia lyocell to have a twist number of 46 and an array density of 24EPI. Two composite cords were applied to a cap ply of a passenger car tire 235 / 40R 17 standard to measure the strength, the median elongation, and the heat shrinkage. The results are summarized in Table 3 below.

<Example 3>

A 1000D-1000D composite cord for a cap ply was prepared by twisting 1000 denia polyethylenenaphthalate and 1000 denia lyocell to have a twist number of 46 and an array density of 30 EPI. One composite cord was applied to a cap ply of a passenger car tire 235 / 40R 17 standard to measure the strength, the median elongation, and the heat shrinkage. The results are summarized in Table 3 below.

<Table 2> Measurement results of the physical properties of Comparative Example 1 and Example 1

Item Comparative Example 1 Example 1 Strong (kg) 23.5 24.55 Medium elongation (4.5kg) (%) 7.5 2.3 Heat Shrinkage (%) (177 ℃ × 2min, free) 4.5 1.6

<Table 3> Measurement results of physical properties of Comparative Example 2 and Examples 2,3

Item Comparative Example 2 Example 2 Example 3 Strong (kg) 23.5 24.55 24.55 Medium elongation (4.5kg) (%) 7.5 1.5 1.5 Heat Shrinkage (%) (177 ℃ × 2min, free) 4.5 1.2 1.2

<Test Example 1>

The cords of Comparative Examples 1 and 1 were tested on cap ply of each passenger car tire standard for durability performance and tire weight, and the results are summarized in Table 4 below. The tire weight of Example 1 is a relative percentage based on Comparative Example 1. In addition, the tire weight of the said Example 2, 3 is a relative percentage based on the comparative example 2.

Table 4 Test Results of Comparative Example 1 and Example 1

Item Comparative Example 1 Example 1 Durability (ECER-30) 1 hour 25 minutes 1 hour 45 minutes Tire weight (relative value) 100% 98%

TABLE 5 Test results of Comparative Example 2 and Examples 2,3

Item Comparative Example 2 Example 2 Example 3 Durability (ECER-30) 1 hour 23 minutes 1 hour 48 minutes 1 hour 40 minutes Tire weight (relative value) 100% 98% 94%

* ECER-30: European tire durability standard test method

As can be seen from the results of Tables 4 and 5, it can be seen that the Examples are superior to the Comparative Examples in terms of durability and tire weight.

As can be seen from the results of the test example, by using the polyethylene naphthalate-lyocell composite fiber composed of polyethylene naphthalate having excellent structural stability and lyocell having excellent adhesion and structural stability, the present invention uses N-66 as a tire cap ply cord. It can be seen that the durability performance is improved compared to the tire cap ply using.

Claims (3)

In the cap fly cord of the tire, Polyethylene naphthalate: Tire cap ply cord, characterized in that the lyocell consists of a composite fiber having a twist number of 10 to 80 in a ratio of 1: 1 to 2 to 1-2: 1. The tire cap ply cord according to claim 1, wherein the arrangement density of the cap ply cord is 10 to 45 EPI. The tire cap ply cord according to claim 1, wherein the polyethylene naphthalate or lyocell is 300 to 2000 denia.