KR100527305B1 - Insulation rubber composition for bias tire of truck or bus having improved properties in heat resistance - Google Patents

Abstract

The present invention relates to an insulation rubber composition for a bias tire of a truck or bus, and more particularly, the raw material rubber is made of natural rubber, styrene butadiene rubber, and recycled rubber, and GPF carbon black and clay are used as reinforcing agents to improve heat resistance. It relates to an insulation rubber composition for a bias tire of a truck or a bus, characterized in that the addition.

Description

INSULATION RUBBER COMPOSITION FOR BIAS TIRE OF TRUCK OR BUS HAVING IMPROVED PROPERTIES IN HEAT RESISTANCE}

The present invention relates to an insulated rubber composition for a bias tire of a truck or bus in which heat resistance is improved by changing carbon black used as a reinforcing agent and adding clay.

In general, the insulated rubber of the bias tire of a truck or bus is located at the innermost part of the tire to provide fatigue and heat resistance characteristics in consideration of cord protection, resistance to continuous stretching, and resistance to heat due to friction with the tube. It must be well designed.

In the prior art, the fatigue characteristics of the tire's stretching motion were mainly designed, but in order to prevent the accident of the tire due to the heat generation due to the friction with the tube, the SRF as a reinforcing agent in the insulated rubber of the bias tire (Semi-reinforcing furnace, ASTM D 1765 classification N774) A technique that uses carbon black and uses about 10 parts by weight of clay has been applied.

However, such a technique still has a problem that the heat resistance is not sufficient.

An object of the present invention is to improve the heat resistance characteristics of the insulated rubber for the bias tires of trucks or buses, the surface area is wider than that of SRF carbon black, instead of increasing the amount of reinforcement that is lower than that of SRF carbon black but increasing the amount of clay having excellent heat resistance. By using the GPF (General-purpose furnace, ASTM D 1765 classification N660) carbon black, which has a more advanced structure and reduced reinforcement, the amount is reduced and compounded so that the physical properties are equivalent to those of the existing rubber composition. It is to provide an insulated rubber composition for a bias tire of a truck or bus, while further improving heat resistance while maintaining an equivalent level with the rubber composition.

The rubber composition of the present invention comprises 30 to 60 parts by weight of natural rubber, 30 to 50 parts by weight of styrene butadiene rubber and 70 to 90 parts by weight of regenerated rubber, and 55 to 70 parts by weight of GPF carbon black as a reinforcing agent to the raw material rubber. And characterized in that it comprises 10 to 25 parts by weight of clay.

It is preferable to use 55-70 weight part of GPF carbon black used for the rubber composition of this invention with respect to raw material rubber. If the content of the GPF carbon black is less than 55 parts by weight, the reinforcement is weak and the desired physical properties do not come out. In order to achieve the desired effect of the present invention, the GPF carbon black preferably has a CTAB adsorption value of 34 to 38 m 2 / g and a DBP adsorption amount of 84 to 96 ml / 100 g. Examples include N660 grade.

Moreover, it is preferable to use 10-25 weight part of clays used by the rubber composition of this invention. Since clay is used as a reinforcing agent like carbon black, not only should it be limited to the overall amount of reinforcing agent in addition to carbon black, but since clay has a significantly lower reinforcing property than carbon black, it is possible to reduce the amount of carbon black to reduce the carbon black. When used as a reinforcing agent, it is difficult to obtain the desired physical properties. It is preferable that the specific gravity of the clay is 2.5 to 2.7, and the 325 mesh passage is 99.5% or more. In the case of clay whose specific gravity content is out of the above range, it contains a large amount of impurities and is not preferable for use.

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 are not intended to limit the protection scope of the present invention.

Examples and Comparative Examples

Comparative Example 1

According to the composition shown in Table 1 (the content unit of each component is parts by weight), using 70 parts by weight of SRF (N774) carbon black and 10 parts by weight of clay as a reinforcing agent, an insulation rubber composition for a bias tire of a truck or a bus is manufactured. It was. The results of measuring the physical properties are shown in Table 1 together.

<Example 1>

According to the composition shown in Table 1, using 65 parts by weight of GPF (N660) carbon black and 20 parts by weight of clay as a reinforcing agent, an insulation rubber composition for a bias tire of a truck or a bus was prepared. The results of measuring the physical properties are shown in Table 1 together.

<Example 2>

According to the composition shown in Table 1 below, 63 parts by weight of GPF (N660) carbon black and 20 parts by weight of clay were used to prepare an insulation rubber composition for a bias tire of a truck or a bus. The results of measuring the physical properties are shown in Table 1 together.

<Example 3>

According to the composition shown in Table 1 below, using 60 parts by weight of GPF (N660) carbon black and 20 parts by weight of clay as a reinforcing agent, an insulation rubber composition for a bias tire of a truck or a bus was manufactured. The results of measuring the physical properties are shown in Table 1 together.

The characteristics of the carbon black used in the above Examples and Comparative Examples are shown in Table 2, and Table 3 shows the characteristics of the clay. And Table 4 shows the results of the durability test (DOT-119) of the 11.00-20 16PR standard tire manufactured using the rubber composition of the comparative example and the embodiment of the present invention.

-The lower the viscosity, the better the processability.

-The tensile strength and elongation rate of the sensible property relative to the initial tensile property are excellent as the decrease is small.

-100% modulus and hardness show better physical properties as the rate of increase of aging property is lower than initial property.

-The exothermic performance shows that the lower the temperature, the better.

-Blow-out performance is excellent with longer break time.

division SRF (N774) GPF (N660) CTAB adsorption value (㎡ / g) 30 to 34 34-38 DBP adsorption amount (ml / 100g) 66-78 84-96

-The CTAB adsorption value is a value representing the surface area, and represents the area (m 2) in which hexadecyltrimethyl ammonium bromide is adsorbed per unit of carbon black, and the higher the CTAB adsorption value, the larger the surface area. In general, the larger the surface area, the higher the hardness, modulus, and tensile strength.

-DBP adsorption amount is a value indicating the structure of carbon black, and the more adsorption amount is developed by DBP (dibutyl phthalate) measurement method, the more developed structure. In general, as the structure develops, hardness, modulus, and tensile strength increase.

division Property value importance 2.6 % Pass through 325mesh 99.5%

-The mesh passing rate indicates the rate of passage through the standard mesh. The larger the value, the smaller the particles and the more uniform the particle distribution.

Comparative Example 1 Example 1 Example 2 Example 3 Durability test result 71 hours 34 minutes 75 hours 12 minutes 75 hours 13 minutes 75 hours 30 minutes

-Durability test shows better performance with longer driving time.

As can be seen from the results of Table 1, the insulated rubber composition for the bias tire of the truck or bus of the present invention was excellent or equal to or better than the comparative example of the conventional rubber composition, the viscosity (tension) and tensile properties, Heat resistance (heating performance) and blow out performance were remarkably superior to the comparative example.

In addition, as can be seen from the results of Table 4, the test tire of the 11.00-20 16PR standard was prepared from the rubber composition of the present invention, and the durability test (DOT-119) was evaluated, and thus the rubber composition of Comparative Example 1 was prepared. Better results than one tire.

As can be seen from the above, the insulated rubber composition for the bias tire of a truck or bus according to the present invention is a GPF carbon black having a wider surface area and a more developed structure than the carbon black which is generally used as a reinforcing agent. By increasing the amount of clay used and increasing the amount of clay to be used in general, there is an effect of improving the heat resistance characteristics without deterioration of the aging properties and other physical properties.

Claims (3)

Regarding the raw material rubber composed of 30 to 60 parts by weight of natural rubber, 30 to 50 parts by weight of styrene butadiene rubber and 70 to 90 parts by weight of regenerated rubber, 55 to 70 parts by weight of GPF carbon black and 10 to 25 parts by weight of clay are used as a reinforcing agent. Insulation rubber composition for a bias tire of a truck or bus, characterized in that. The method of claim 1, wherein the GPF carbon black has a CTAB adsorption value of 34 to 38 m 2 / g, DBP adsorption amount of 84 to 96 (ml / 100 g), the clay has a specific gravity of 2.5 to 2.7, 325 mesh passage of more than 99.5% Insulation rubber composition for a bias tire of a truck or a bus, characterized in that. A bias tire for a truck or a bus, wherein the rubber composition according to claim 1 or 2 is applied to an insulation rubber.