KR100716040B1 - Rubber composition for truck/bus tire tread - Google Patents

Abstract

The present invention relates to a rubber composition of a tread for trucks / buses, comprising 50% by weight of natural rubber, 10-30% by weight of high cisodymium-butadiene rubber, and 10-30% by weight of styrene-butadiene rubber. Wear-resistant, by including a reinforcing carbon black having a nitrogen adsorption specific surface area 110 ~ 116mg / g, DBP oil absorption 130 ~ 140cc / 100g, TINT value 120 ~ 130 to 50 to 60 parts by weight based on 100 parts by weight of the raw material rubber Braking performance and durability can be improved at the same time.

Abrasion Resistance * Durability * Braking Performance * Tread * Rubber

Description

Rubber composition for truck / bus tire treads {Rubber composition for truck / bus tire tread}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber tread rubber composition for trucks / buses, and more particularly, to a low glass transition temperature of nidium-butadiene rubber and braking (Traction), which is advantageous for abrasion performance in a certain ratio of natural rubber. ) A solution polymer type styrene-butadiene rubber, which is advantageous for performance, is used as a raw material rubber, and carbon black, which has high wear and heat resistance, is used to simultaneously improve wear, braking and durability. A rubber composition for tire treads for trucks / buses.

In general, truck / bus tires are made of natural rubber, which has high molecular weight and high elasticity due to its high load durability, and has excellent heat resistance. The use of carbon black with small particle diameter and excellent reinforcing performance as a reinforcing agent can improve wear resistance. However, the use of carbon black with small particle diameter increases heat generation due to friction between carbon blacks, resulting in heat generation and durability. There was a disadvantage to be disadvantaged.

In order to remove the limited performance of the carbon black and improve the wear resistance, butadiene rubber having a low glass transition temperature is required. Japanese Patent Laid-Open No. 1995-118443 gives an example of using butadiene rubber having high linearity and narrow molecular weight distribution (Narrow MWD) and carbon black satisfying specific colloidal properties. In this patent, the wear resistance can be improved by using butadiene rubber, which is a synthetic rubber. However, the mechanical strength of the rubber is lower than that of natural rubber, and the durability is disadvantageous. Therefore, the braking performance is lowered, in particular, the Wet Traction is disadvantageous. In addition, increasing the content of synthetic rubber or carbon black in the rubber composition improves abrasion resistance, but disadvantages in hysteresis, resulting in lower fuel efficiency.

As such, it is very difficult to configure a rubber composition for truck tread tire treads that can satisfy three performances of abrasion resistance, braking, and fuel efficiency at the same time.

Therefore, the present invention is for the manufacture of a tread rubber composition for truck / bus tires satisfying all three characteristics of abrasion resistance, braking resistance, and fuel economy, and a solution of neodymium-butadiene rubber in 50% by weight of natural rubber Carbon black having specific colloidal properties is used as a raw material rubber using a certain amount of polymerized styrene-butadiene rubber.

Accordingly, an object of the present invention is to provide a tread rubber composition of a truck / bus tire that satisfies all three characteristics of wear resistance, braking resistance, and fuel economy.

The tread rubber composition of the truck / bus tire of the present invention for achieving the above object is 50% by weight of natural rubber, 10-30% by weight of high cisodymium-butadiene rubber, and 10-30% by weight of styrene-butadiene rubber. 50 to 60 parts by weight of reinforcing carbon black having 100 parts by weight of the raw material rubber, a nitrogen adsorption specific surface area of 110 to 116 mg / g, a DBP oil absorption of 130 to 140 cc / 100 g, and a TINT value of 120 to 130, based on 100 parts by weight of the raw material rubber. It is characterized by including as possible.

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

The raw material rubber of the present invention is composed of rubber cisodymium-butadiene rubber and styrene-butadiene rubber in a fixed amount of natural rubber.

The natural rubber of the present invention is not particularly limited as long as it is included in ordinary tire tread rubber, and is included in 50% by weight of the total raw rubber.

The butadiene rubber can be used in the production of a number of catalysts, niobium-butadiene rubber prepared using the niobium catalyst has a sheath content (97 ~ 99%) than the butadiene rubber prepared using a cobalt or nickel catalyst It has a high molecular weight, a low degree of branching and high linearity, which is advantageous over other butadiene rubbers in terms of wear resistance and heat generation. The high cisodymium-butadiene rubber of this invention means that the cis content is 97 to 99%. In addition, the niobium-butadiene rubber has a molecular weight distribution (molecular weight distribution) of 2.0 to 3.5, it is preferable that the glass transition temperature is -103 to -110 ℃.

It is preferable that such niobium-butadiene rubber is contained in 10 to 30% by weight of the total raw rubber, the braking performance may be lowered outside this range.

The solution-polymerized styrene butadiene (S-SBR) rubber used for braking performance is characterized by a styrene content of 13-17% and a vinyl content of 28-33%. Good heat resistance and other physical properties compared to butadiene rubber. The solution-polymerized styrene-butadiene rubber is also preferably included in 10 to 30% by weight of the total raw rubber bar, if out of this range hysteresis (Hysteresis) is disadvantageous to reduce the fuel economy performance.

The raw material rubber of the present invention is contained in 50% by weight of natural rubber, the sum of the niobium-butadiene rubber and the solution-polymerized styrene-butadiene rubber does not exceed 50% by weight of the total raw rubber wear resistance, braking, It is preferable at the point which can satisfy all the fuel economy performance.

Carbon black with specific colloidal properties suitable for abrasion resistance, braking, and fuel efficiency is used for the raw material rubber compounding ratio. It is preferable to use in the range of 50-60 weight part with respect to 100 weight part of said raw material rubbers as 100g, TINT value 120-130.

In addition to the above composition, the rubber composition of the present invention can add the usual additives included in the tire tread rubber composition for bus / truck.

Hereinafter, the present invention will be described in more detail with reference to the following examples and comparative examples, as follows. However, the present invention is not limited thereto.

Examples and Comparative Examples 1 and 2

Next, according to the composition as shown in Table 1, rubber compositions of Examples and Comparative Examples were prepared, and the manufacturing method was in accordance with the conventional tire tread rubber composition.

Table 1

The physical properties of the rubber composition were measured by using an instron to cut the rubber specimen into a dumbbell shape to measure hardness, 100% modulus and tensile strength. The fuel efficiency was measured in an indoor RR tester, the braking property was measured in the Test Track, and the value of the comparative example was expressed as an index based on 100, and the larger the value, the better. The measured physical properties are shown in Table 2 below.

Table 2

Properties Comparative Example 1 Comparative Example 2 Example Hardness 68 67 68 100% modulus 32 29 32 The tensile strength 330 278 315 Actual vehicle wear results 100 112 125 R. R. (fuel economy) 100 90 102 Wet Traction 100 102 105

As shown in the results of Table 2, the Example is significantly improved wear resistance compared to Comparative Examples 1 and 2, it can be seen that the fuel economy and braking properties are also secured at an equivalent level or higher than Comparative Example 1. Compared to Comparative Example 1, Comparative Example 2 also has improved wear resistance but very poor fuel economy and braking performance. Example compared to Comparative Example 1, the raw material rubber composition ratio is the same but by using a high structure (High Structure) carbon black to improve the fuel economy performance it can be seen that all three performances of wear resistance, fuel economy, braking is improved.

As described in detail above, a high-polymerization nitricium-butadiene rubber having a low glass transition temperature, which is advantageous for abrasion performance, and a solution-polymerized styrene-butadiene, which is advantageous for braking performance, in a certain ratio of natural rubber. -Butadiene) A mixture of rubber is used as a raw material rubber, and carbon black, which has excellent wear and heat resistance, can be used to improve abrasion resistance, braking performance and durability.

Claims (3)

In the rubber composition of the tread for trucks / buses, 100 parts by weight of the raw material rubber consisting of 50% by weight of natural rubber, 10-30% by weight of high cis niobium-butadiene rubber, and 10-30% by weight of styrene-butadiene rubber, A truck comprising a reinforcing carbon black having a nitrogen adsorption specific surface area of 110 to 116 mg / g, a DBP oil absorption of 130 to 140 cc / 100 g, and a TINT value of 120 to 130 to 50 to 60 parts by weight based on 100 parts by weight of the raw material rubber. Rubber composition of the tread for / bus. The truck according to claim 1, wherein the natural rubber is fixed at 50% by weight, and the sum of the high cisodymium-butadiene rubber and the styrene-butadiene rubber does not exceed 50% by weight of the total raw rubber. Rubber composition of the tread for / bus. The method of claim 1, wherein the high cis niobium-butadiene rubber has a cis content of 97-99%, a molecular weight distribution of 2.0-3.5, a glass transition temperature of -103 to -110 ° C; Styrene-butadiene rubber is a tire-tread rubber composition for trucks / buses, characterized in that the solution polymerization type of styrene content of 13 to 17%, vinyl content of 28 to 33%, glass transition temperature of -60 to -70 ℃.