KR20060033580A - Tread compound for truck and bus tire improved abrasion - Google Patents

Abstract

In the tread rubber composition for known truck and bus tires, the present invention relates to carbon black having a nitrogen adsorption specific surface area of 130 to 150 m 2 / g and a DBP adsorption amount of 120 to 140 ml / mg based on 100 parts by weight of raw rubber. , Carbon black 1) 25 to 35 parts by weight, nitrogen adsorption specific surface area of 90 ~ 110㎡ / g, DBP adsorption amount of 105 ~ 125ml / ㎎ carbon black (hereinafter referred to as 'carbon black 2' 15 to 30 parts by weight, characterized in that it comprises 0.1 to 5 parts by weight of the process aid.

As described above, the present invention is carbon black 1, which is advantageous for the wear of small particle size and developed structure, and carbon, which is advantageous in heat generation and processability, which has a large particle size and less structure, which is used as a reinforcement of the tread rubber of a truck bus tire. By using Black 2 at the same time and increasing the carbon content while mixing the chemicals having favorable properties for heat generation and processability, wear resistance performance can be improved without deterioration in durability performance and heat generation performance.

Abrasion Resistance, Tread, Heat Generation Performance

Description

Tread Compound for Truck and Bus Tire Improved Abrasion

The present invention relates to a tread rubber composition for truck and bus tires, and more particularly to a tread rubber composition for truck and bus tires with improved wear resistance without a decrease in durability performance and heat generation performance.

Recently, due to the high performance of automobiles and the development of highways, not only the driving speed is increased in vehicles such as trucks and buses, but also the severity of truck and bus tires is increasing due to the increase in load weight due to deregulation. Therefore, there is a need for a tread rubber having excellent wear resistance under such harsh conditions. In addition, in the tires for trucks and buses that travel much longer than ordinary cars, excellent heat generation performance is also required.

Conventionally, as a determinant of tire wear resistance, the particle size and structure of carbon black used as a reinforcing agent of the rubber composition have been considered as the dominant factor. The smaller the particle size of the carbon black is, the better the wear resistance is, but the processability and heat generation performance are deteriorated. It is known to become. In addition, as the structure of carbon black develops, wear resistance is improved, but processability and exothermic performance are deteriorated.

The wear resistance tends to increase as the amount of carbon black used increases, but if a certain amount is used, the wearability also decreases as well as the fairness and the exothermic performance.

As described above, development of a rubber composition having improved processability and improved wear performance has been performed. For example, Japanese Laid-Open Patent Publication No. 63-112638 (name: tire tread rubber composition) has developed a rubber composition using carbon black, which is broad in aggregate of carbon black. [0003] In Japanese Patent Laid-Open No. 61-207452 (name: Rubber composition for tire tread), a rubber composition using carbon black having a surface modified with excellent reactivity with rubber has been developed.

However, although the required performance for truck-bus tires is increasing, rubber compositions proposed in the above patents are easily used for performances (tires having excellent heat generating performance and wear performance under severe conditions) in recent years. Not only is it difficult to cope, it is also difficult to apply to mass production in terms of supply and demand for raw materials.

Invented to achieve the above object, the present invention is carbon black 1, which is advantageous for the wear of the structure is small and the particle size is used as a reinforcement of the tread rubber of the tire for truck buses, the particle size is large and the structure is less developed In addition to using a mixture of carbon black 2, which is advantageous for heat generation and fairness, and simultaneously increasing the carbon content, a compound having advantageous properties for heat generation and fairness is mixed together to improve wear resistance without deterioration in durability performance and heat generation performance.

In order to achieve the above object, the present invention is a known tread rubber composition for truck and bus tires, the nitrogen adsorption specific surface area is 130 ~ 150 m 2 / g to 100 parts by weight of the raw material rubber, DBP adsorption amount 120 ~ 140ml / 25 mg to 35 parts by weight of carbon black (hereinafter referred to as' carbon black 1 '), nitrogen adsorption specific surface area of 90 to 110 m 2 / g, and carbon black having a DBP adsorption amount of 105 to 125 ml / mg (hereinafter,' Carbon black 2 ') 15 to 30 parts by weight, characterized in that it comprises 0.1 to 5 parts by weight of the process aid.

Preferably, as the process aid, zinc soap (Zinc Soap, name: EF-44, manufacturer: STRUCTOL) having a 3: 1 ratio of zinc to potassium is applied.

When the carbon black 1 is added below 25 parts by weight, the wear performance is lowered. When the carbon black 1 is added above 35 parts by weight, heat generation rises rapidly, which is not preferable.

In addition, when the carbon black 2 is added below 15 parts by weight, heat generation is increased, and when the carbon black 2 is added above 30 parts by weight, wear performance is lowered, which is not preferable.

In addition, the addition of the process aid in excess of 5 parts by weight is not preferable because the physical properties are lowered.

As the raw material rubber, natural rubber, styrene-butadiene rubber, butadiene rubber or mixed rubber thereof may be used.

Table 1 compares the properties of Carbon Black 1 and Carbon Black 2 used in the present invention.

Table 1 Comparison of Properties of Carbon Black 1 and Carbon Black 2

division Carbon Black 1 Carbon black 2 Nitrogen adsorption specific surface area (㎡ / g) 130 to 150 90 to 110 DBP adsorption amount (ml / mg) 120 to 140 105 to 125

1) The nitrogen adsorption specific surface area represents a surface area and represents an area (m 2) in which nitrogen is adsorbed per unit of carbon black, and the larger the value, the smaller the particle size.

2) DBP adsorption amount is a value representing the structure of carbon black, and the adsorption amount measurement method by DBP (DiButyl Phthalate) shows a structure that is developed as the value becomes larger.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to these examples.

Comparative Example 1

As shown in the compounding ratio shown in Table 2 below, based on 100 parts by weight of natural rubber, 50 parts by weight of carbon black 1, 3.5 parts by weight of zinc, 3.5 parts by weight of stearic acid, 1.5 parts by weight of an ozonation inhibitor, 1 part by weight of anti-aging agent, and 1 weight of wax Part, 3 parts by weight of oil, 1.6 parts by weight of sulfur, 1.0 part by weight of vulcanization accelerator, and a tread rubber specimen was prepared using a Banbury mixer.

Comparative Example 2

A rubber specimen was manufactured using the same composition, composition, and method as in Comparative Example, except that 30 parts by weight of carbon black 1 and 20 parts by weight of carbon black 2 were further applied.

<Example 1>

30 parts by weight of carbon black 1 was applied, and 23 parts by weight of carbon black 2 and 3 parts by weight of a process aid were used to prepare a rubber specimen using the same composition, composition ratio, and method as in Comparative Example.

<Example 2>

A rubber specimen was prepared using the same composition, composition, and method as in Comparative Example, except that 30 parts by weight of carbon black 1 was applied, and 25 parts by weight of carbon black 2 and 3 parts by weight of a process aid were applied.

TABLE 2 Rubber compositions of Comparative Examples 1 and 2 and Examples 1 and 2

division Comparative Example 1 Comparative Example 2 Example 1 Example 2 Natural rubber 100 100 100 100 Carbon Black 1 50 30 30 30 Carbon black 2 - 20 23 25 Process - - 3.0 3.0 Zincification 3.5 3.5 3.5 3.5 Stearic acid 2.0 2.0 2.0 2.0 Ozone aging inhibitor 1.5 1.5 1.5 1.5 Anti-aging 1.0 1.0 1.0 1.0 Wax 1.0 1.0 1.0 1.0 oil 3.0 3.0 3.0 3.0 sulfur 1.6 1.6 1.6 1.6 accelerant 1.0 1.0 1.0 1.0

<Test Example 1>

Comparative Examples and Examples The rubber specimens were measured for physical properties according to ASTM-related regulations, and the results are shown in Table 2 below.

(1) The heat generation performance shows that the lower the temperature rise, the better.

(2) The abrasion performance shows that the smaller the amount generated, the better.

(3) modulus

The measurement is carried out with a tensile tester (Model 4502) manufactured by Instron, by cutting the specimen into dumbbells. 300% modulus refers to the stress acting on the specimen when the specimen is stretched 300%. The higher the value, the better the performance.

<Table 3> Measurement results of the physical properties of Comparative Examples 1 and 2 and Examples 1 and 2

division Comparative Example 1 Comparative Example 2 Example 1 Example 2   Tensile Properties Hardness, Shore A method 66 65 68 69 300% modulus, kg / cm ² 150 152 168 172 Tensile strength, kg / cm ² 293 295 291 293 Elongation,% 534 523 472 475 Viscosity 100 ℃ 78 76 75 78 Exothermic performance Temperature rise, ℃ 25.5 24.1 24.5 25.3 Wear Generation amount (g) 0.022 0.021 0.016 0.017

As shown in Table 3, the physical property measurement results are as follows.

1) The embodiment according to the present invention can be seen that the equivalent to the comparative example in terms of tensile properties and exothermic performance.

2) Example according to the invention can be seen that the improvement in wear resistance than the comparative example.

<Test Example 2>

The durability performance (ECER-40) and the actual vehicle wear of the tire (standard: 12R22.5 16PR) manufactured from the tread rubber composition of the truck bus tire according to the comparative example and the embodiment were measured, and the results are shown in Table 4 below. As shown.

(1) The durability test shows better performance with longer running time.

(2) Actual vehicle wear indicates that the higher the index value, the better the wear resistance.

<Table 4> Durability test and actual vehicle wear measurement results of Comparative Examples 1 and 2 and Examples 1 and 2

division Comparative Example 1 Comparative Example 2 Example 1 Example 2 Durability test result 64 hours 48 minutes 64 hours 50 minutes 65 hours 18 minutes 64 hours 3 minutes Actual car wear index 100 99 113 107

As shown in Table 4, the durability test and the actual vehicle wear measurement results are as follows.

1) The embodiment according to the present invention can be seen that the equivalent to the comparative example in terms of durability performance.

2) Example according to the invention can be seen that the improvement in wear resistance than the comparative example.

As described above, the present invention is carbon black 1, which is advantageous for the wear of small particle size and developed structure, and carbon, which is advantageous in heat generation and processability, which has a large particle size and less structure, which is used as a reinforcement for tread rubber of truck bus tires. By using Black 2 simultaneously and increasing the carbon content while mixing the chemicals having favorable properties for heat generation and processability, the wear resistance performance can be improved without a decrease in durability and heat generation performance.

Claims (2)

In known tread rubber compositions for truck and bus tires, Nitrogen adsorption specific surface area is 130-150m2 / g, 100-part by weight of raw material rubber, 25-35 parts by weight of carbon black with DBP adsorption amount 120-140ml / mg, 90-110m2 / g nitrogen adsorption , 15-30 parts by weight of carbon black having a DBP adsorption amount of 105 to 125 ml / mg, and 0.1 to 5 parts by weight of a process aid. The tread rubber composition for truck and bus tires according to claim 1, wherein the process aid is zinc soap having a zinc to potassium ratio of 3: 1.