KR100449891B1 - Tread compound for truck and bus tire - Google Patents

Abstract

The present invention relates to a tread rubber composition of a tire for truck buses, and more particularly, to a tread rubber composition of truck and bus tires for driving on a highway having excellent heat and wear resistance.

The present invention is a tread rubber composition of a truck bus tire comprising a known additive as a means for achieving the above object, 1,6-bis (N, N'- dibenzylthio based on 100 parts by weight of natural rubber It provides a tread rubber composition of a truck bus tire comprising 0.5-1.0 parts by weight of carbamoylthio) -hexane and 1.0-3.0 parts by weight of N-1,3-dimethylbutyl-N'-phenylquinone diimine.

Description

Tread compound for truck and bus tire

The present invention relates to a tread rubber composition of a tire for truck buses, and more particularly, to a tread rubber composition of truck and bus tires for driving on a highway having excellent heat and wear resistance.

High speed driving is increasing due to the increase of pavement along with industrialization, but rubber composition which uses natural rubber, which is the most used as tread rubber for trucks and buses, is made of unsaturated bond and Due to the double bond, the heat generated during high-speed driving causes a decrease in the wear resistance, tearing properties of the rubber properties, uneven wear and uneven wear.

The heat resistance and abrasion resistance of the tread for tires are determined by the properties of the tread surface layer in contact with the ground. The inevitable heat generation during high-speed driving causes the deterioration of physical properties and wear resistance.

Conventionally, in order to solve such a phenomenon, an anti-aging agent having good heat resistance is used for rubber, or a mixed use of rubber, that is, natural rubber (NR) / styrene-butadiene rubber (SBR), natural rubber / butadiene rubber (BR) or natural rubber In the form of / styrene-butadiene rubber / butadiene rubber, a method of using a mixture of rubber or a method of improving the thermal stability by changing the crosslinking agent into a single sulfur bond (monosulfide bond) rather than a polysulfide bond has been tried. come.

However, these conventional methods have a problem in that rubber properties, in particular, have a limitation in satisfying tensile strength characteristics, low fuel consumption characteristics and braking force characteristics required in tires at the same time.

The present inventors have been able to solve these problems through the selection of additives having excellent thermal stability and proper adjustment of the amount of additives, while studying the solutions to the problems of the tread rubber composition of the conventional truck bus tires as described above. It was found and completed the present invention.

Accordingly, an object of the present invention is to provide a tread rubber composition of a tire for trucks and buses having excellent heat and wear resistance.

The present invention is a tread rubber composition of a truck bus tire comprising a known additive, 1,6-bis (N, N'-dibenzylthiocarbamoylthio) -hexane 0.5-1.0 based on 100 parts by weight of natural rubber By weight, N-1,3-dimethylbutyl-N'-phenylquinone diimine is characterized in that the tread rubber composition of the tire for truck buses comprising 1.0-3.0 parts by weight.

The tread rubber composition according to the present invention is a rubber composition which uses natural rubber alone as a raw material rubber, with respect to 100 parts by weight of raw material rubber, 1-3 parts by weight of stearic acid, 3-6 parts by weight of zinc oxide, and 40-65 parts by weight of carbon black. Silica, 0-15 parts by weight, and other plasticizers, softeners and the like.

1,6-bis (N, N'-dibenzylthiocarbamoylthio) having excellent thermal stability with respect to 100 parts by weight of natural rubber as a raw material rubber in order to improve thermal aging characteristics and abrasion resistance characteristics according to the present invention ) -Hexane (1,6-bis (N, N'-dibenzylthiocarbamoyldithio) hexane) 0.5-1.0 parts by weight, N-1,3-dimethylbutyl-N'-phenylquinone diimine (N-1,3-dimethylbutyl- 1.0-3.0 parts by weight of N'-phenylquinone diimine) is added.

The use ratio of 1,6-bis (N, N'-dibenzylthiocarbamoylthio) -hexane and N-1,3-dimethylbutyl-N'-phenylquinone diimine used in the present invention is 1: 2. It is preferable to add in a ratio of 1: 6, but the thermal stability and wear resistance of the rubber composition are relatively insignificant in the range below the use ratio applied to the present invention, and in the above range, the heat aging and other physical properties No more improvements

1,6-bis (N, N'-dibenzylthiocarbamoylthio) -hexane as used in the present invention is a crosslinking agent that increases heat dissipation and destruction by increasing a mono-disulfide bond or hybrid bond in a polymer chain. ) And blow out properties, and N-1,3-dimethylbutyl-N'-phenylquinone diimine is an anti-aging agent that significantly reduces the drop in physical properties, especially at high temperatures or high heat. Do it.

1,6-bis (N, N'-dibenzylthiocarbamoylthio) -hexane and N-1,3-dimethylbutyl-N'-phenylquinone diimine used in the tread rubber composition according to the present invention alone When used in combination, the effect is remarkably excellent. 1,6-bis (N, N'-dibenzylthiocarbamoylthio) -hexane and N-1,3-dimethylbutyl-N'-phenyl It seems to be due to the synergy effect of quinone diimine.

Other components included in the tread rubber composition according to the present invention, for example, active agents, reinforcing agents, process oils, anti-aging agents, stearic acid and the like are additives of known truck tire tread rubber compositions, each of which is in the range of known addition amount Therefore, it is enough to carry out by appropriate selection, so detailed description thereof will be omitted. Hereinafter, the contents of the present invention will be described in detail through Examples and Comparative Examples. However, the following examples are intended to illustrate the present invention in more detail, and are not intended to limit the scope of the invention.

<Example 1>

50 parts by weight of carbon black, 0.5 parts by weight of 1,6-bis (N, N'-dibenzylthiocarbamoylthio) -hexane (hereinafter referred to as DBTH) based on 100 parts by weight of natural rubber as shown in Table 1 below. , N-1,3-dimethylbutyl-N'-phenylquinone diimine (hereinafter 6-QDI) 1.5 parts by weight, process oil 5 parts by weight, zinc oxide 4 parts by weight, stearic acid 1 part by weight, free sulfur 1.2 parts by weight , 0.6 parts by weight of a vulcanization accelerator was added to the Banbury mixer and discharged at a temperature of 105 ° C. to prepare a rubber composition.

<Example 2>

Example 1,6-bis (N, N'-dibenzylthiocarbamoylthio) -hexane 0.7 parts by weight, except that it was composed of 3.0 parts by weight of N-1,3-dimethylbutyl-N'-phenylquinone diimine The rubber composition was prepared under the same conditions as in 1.

<Example 3>

Example 1,6-bis (N, N'-dibenzylthiocarbamoylthio) -hexane 1.0 part by weight, except that it was composed of 4.5 parts by weight of N-1,3-dimethylbutyl-N'-phenylquinone diimine The rubber composition was prepared under the same conditions as in 1.

<Example 4>

0.3 part by weight of 1,6-bis (N, N'-dibenzylthiocarbamoylthio) -hexane, 1.5 parts by weight of N-1,3-dimethylbutyl-N'-phenylquinone diimine, and 1.5 parts by weight of free sulfur A rubber composition was prepared under the same conditions as in Example 1 except that the part was composed of parts.

Comparative Example 1

1.8 parts by weight of free sulfur without adding 1,6-bis (N, N'-dibenzylthiocarbamoylthio) -hexane and N-1,3-dimethylbutyl-N'-phenylquinone diimine Except for the same conditions as in Example 1 to prepare a rubber composition.

Comparative Example 2

0.7 parts by weight of 1,6-bis (N, N'-dibenzylthiocarbamoylthio) -hexane, except that N-1,3-dimethylbutyl-N'-phenylquinone diimine was not added. A rubber composition was prepared under the same conditions as in Example 1.

Comparative Example 3

Except that 1,6-bis (N, N'-dibenzylthiocarbamoylthio) -hexane was not added and N-1,3-dimethylbutyl-N'-phenylquinone diimine was composed of 2.0 parts by weight. A rubber composition was prepared under the same conditions as in Example 1.

<Table 1> Rubber Blend (Unit: parts by weight)

division Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Natural rubber 100 100 100 100 100 100 100 Carbon black 50 50 50 50 50 50 50 DBTH 0.5 0.7 1.0 0.3 - 0.7 - 6-QDI 1.5 3.0 4.5 1.5 - - 2.0 Process oil 5 5 5 5 5 5 5 Zinc oxide 4 4 4 4 4 4 4 Stearic acid One One One One One One One Free sulfur 1.2 1.2 1.2 1.5 1.8 1.2 1.2 accelerant 0.6 0.6 0.6 0.6 0.6 0.6 0.6

<Test Example 1>

The rubber compositions prepared in Examples and Comparative Examples were vulcanized under a load of 30 tons at 145 ° C. for 30 minutes to prepare tensile specimens, followed by hardness, 300% modulus, tensile strength, elongation break, and fracture. Reversion ratio, wear performance (PICO) and exothermic properties were measured.

Physical properties of the rubber compound were measured according to ASTM standard, and the results are shown in Table 2. At this time, the fracture rate was calculated using the MDR apparatus at the temperature of 180 ° C. using the following equation.

(Torque-torque at 6 minutes) X 100 / (maximum torque-minimum torque)

<Table 2> Property Test Results

division Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Hardness (shore-A) 64 64 64 63 61 63 62 300% modulus (Kg / ㎠) 127 135 136 115 98 125 105 Tensile Strength (Kg / ㎠) 190 170 161 180 179 181 175 Elongation (%) 502 510 531 518 532 525 570 Breakdown rate (%) 180 ℃, 6 minutes 190 ℃, 6 minutes 200 ℃, 6 minutes 111317 6.210.113.2 11.015.721.6 252835 283246 252939 222632 Wear resistance (PICO, g) 0.0157 0.0115 0.0332 0.0659 0.075 0.0425 0.05944 Exothermic Characteristics (℃) 25 22 23 28 35 26 30

As shown in Table 2 above, it can be seen that the rubber composition using DBTH and 6-QDI has significantly improved heat aging characteristics during rdhskrkb. In particular, the exothermic properties of DBTH and 6-QDI were lower than those of DBTH and 6-QDI, and the low heat and wear resistance were significantly improved.

In case of using DBTH or 6-QDI alone, the improvement of heat aging characteristics and abrasion resistance is insignificant compared to the case of mixing DBTH and 6-QDI alone. This means that DBTH and 6-QDI doubled during the vulcanization process. It shows the effect.

In addition, the use of DBTH and 6-QDI in combination with the breakdown ratio of crosslinking rate during high temperature curing showed a remarkably superior effect than when DBTH and 6-QDI were not used at all.

<Test Example 2>

The abrasion resistance and wear resistance of the 11R22.5 956 standard tires manufactured using the tread rubber composition according to the present invention were tested. The results are shown in Table 3. In this case, the index of wear resistance is a value of 100 as Comparative Example 1, which does not use DBTH and 6-QDI at all, which means that the higher the wear index and the lower the occurrence of uneven wear, the better the performance.

Table 3 Performance of Tires Made from Rubber Compositions According to the Present Invention

division Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Wear test 128 130 128 104 100 110 102 Single wear rate (%) 25 20 25 50 70 30 55

As shown in Table 3, the wear resistance when the mixed use of DBTH and 6-QDI is relatively excellent, which is relatively less abrasion occurrence than when the DBTH and 6-QDI is not used at all, It can be seen that it is due to the difference in heat aging characteristics.

The tread rubber composition of the tire for truck buses according to the present invention is excellent in heat and abrasion resistance to prevent changes in physical properties such as deterioration of heat and abrasion resistance due to heat generation inevitably during high speed driving.

Claims (2)

In a tread rubber composition of a truck bus tire comprising a known additive, 0.5-1.0 parts by weight of 1,6-bis (N, N'-dibenzylthiocarbamoylthio) -hexane, 1.0 parts of N-1,3-dimethylbutyl-N'-phenylquinone diimine based on 100 parts by weight of natural rubber Tread rubber composition of the tire for truck bus, characterized in that it comprises -3.0 parts by weight. The use ratio of 1,6-bis (N, N'-dibenzylthiocarbamoylthio) -hexane and N-1,3-dimethylbutyl-N'-phenylquinone diimine is 1: 2. -1: Tread rubber composition of the tire for truck bus, characterized in that 6.