KR20070000089A - Tire tread rubber composition having an improved wear resistance - Google Patents

Abstract

Provided is a tire tread rubber composition which is improved in rolling resistance characteristics and abrasion resistance without the deterioration of wet traction. The tire tread rubber composition comprises 100 parts by weight of a rubber material which comprises 80 wt% or more of a solution polymerization styrene-butadiene rubber whose vinyl content is 20-40 wt%; 30-70 parts by weight of silica; and 30-70 parts by weight of carbon black. Preferably the rubber material comprises further 20 wt% or less of a natural rubber, a butadiene rubber or an emulsion polymerization styrene-butadiene rubber.

Description

Tire tread rubber composition with improved wear resistance {TIRE TREAD RUBBER COMPOSITION HAVING AN IMPROVED WEAR RESISTANCE}

The present invention relates to a tire tread rubber composition having improved abrasion resistance, and more particularly, by using a raw material rubber containing at least 80% by weight of a solution-polymerized styrene-butadiene rubber (SBR) having a vinyl content of 20 to 40% by weight, The present invention relates to a tire tread rubber composition having improved rolling resistance characteristics and wear resistance without a decrease in wet traction performance.

Solution-polymerized styrene-butadiene rubber (SBR) is a rubber produced by polymerizing styrene monomer and 1,3-butadiene butomer in solution. When used as a raw material for a tread composition, it provides a good tread performance and fuel efficiency. It can be widely used. In addition, a technique of using silica as a filler in a tire tread rubber composition is widely used. This means that when silica is used as a filler, braking performance and fuel efficiency on wet roads can be improved at the same time as a compound using carbon black. Because. For example, Korean Patent Laid-Open Publication No. 2003-0094535 discloses a technology of improving rotation resistance and braking performance by applying silica to a rubber tread rubber composition, and Korean Patent Laid-Open Publication No. 2003-0042911 discloses a rubber composition for tires. Disclosed is a technique of applying silica, nanoclay, and the like to excellent low fuel consumption performance.

Therefore, in the related art, in order to reduce fuel consumption due to traction performance and environmental problems of automobiles, a rubber composition for tire treads has been prepared using solution-polymerized styrene-butadiene rubber as a raw material rubber and silica as a filler. However, in the case of the silica applied tread rubber composition, when the rotational resistance performance and the traction performance are improved, the wear resistance decreases. On the contrary, when the rotational resistance characteristic and the wear resistance are improved, the wet traction performance decreases. Improving either wear resistance and traction performance has a serious problem that causes the other to fall.

The present invention is to solve the problems of the prior art as described above, an object of the present invention is to provide a tread rubber composition with improved rotational resistance characteristics and wear resistance without a decrease in wet traction performance.

According to the present invention, 100 parts by weight of raw material rubber, 30 to 70 parts by weight of silica and 30 to 70 parts by weight of carbon black, containing 80% by weight or more of a solution-polymerized styrene-butadiene rubber (SBR) having a vinyl content of 20 to 40% by weight. There is provided a tire tread rubber composition comprising.

In the tread rubber composition according to the present invention, the vinyl content of the solution-polymerized styrene-butadiene rubber (SBR) contained in the raw material rubber is 20 to 40% by weight, if the content is less than 20% by weight, wear resistance is worse, When it exceeds 40 weight%, wet traction performance will worsen.

In the tread rubber composition according to the present invention, the raw material rubber contains more than 80% by weight of the solution-polymerized styrene-butadiene rubber (SBR), if the content is less than 80% by weight, rotation resistance characteristics without a decrease in wet traction performance And it becomes difficult to improve the wear resistance. In addition, the raw material rubber may further include 20% by weight or less of natural rubber and / or synthetic rubber, and examples of the synthetic rubber include butadiene rubber (BR), emulsion polymerization styrene-butadiene rubber, and the like. When the content of the natural rubber and / or synthetic rubber in the raw material rubber exceeds 20% by weight, the content of the solution-polymerized styrene-butadiene rubber (SBR) is relatively lowered, so that the rolling resistance characteristics and the wet traction performance without degradation It is difficult to improve the wear resistance.

The tread rubber composition according to the present invention contains 30 to 70 parts by weight of silica and 30 to 70 parts by weight of carbon black as a filler with respect to 100 parts by weight of the raw material rubber. If the amount of the silica and carbon black is less than 30 parts by weight, the intended reinforcing effect may not be obtained, and if the amount of the silica and carbon black is more than 70 parts by weight, the workability may be deteriorated.

In addition to the above components, the tread rubber composition according to the present invention may include additives commonly used in the rubber tread rubber composition, and include, for example, a vulcanizing agent, a vulcanization accelerator, a reinforcing agent, a softening agent, a zinc, a process oil, and the like. Can be.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the scope of the present invention is not limited to the following Examples.

<Examples 1-3 and Comparative Examples 1-3>

Next, the rubber compositions of Examples 1 to 3 (E1 to E3) and Comparative Examples 1 to 3 (CE1 to CE3) were prepared according to the compositions shown in Table 1, and then rubber specimens were prepared therefrom. Are listed in Table 1. In addition, the styrene content, vinyl content and glass transition temperature of the styrene-butadiene rubbers used in the preparation of the rubber compositions of Examples and Comparative Examples are listed in Table 2.

TABLE 1

Composition (part by weight) Properties E-SBR S-SBR1 S-SBR2 S-SBR3 BR C / B SI HD 300% MOD TS EB T _g 0 ℃ Tanδ 70 ℃ Tanδ PICO E1 - - - 80 20 30 40 69 133 175 384 -15.0 0.426 0.124 0.026 E2 20 - - 80 - 30 40 68 128 182 413 -15.1 0.428 0.126 0.026 E3 - - - 80 20 30 70 80 100 170 400 -15.0 0.416 0.121 0.023 CE1 40 40 - - 20 30 40 66 116 207 499 -15.0 0.430 0.140 0.030 CE2 - - 80 - 20 30 40 67 102 139 389 -19.1 0.354 0.143 0.029 CE3 - 80 - - 20 30 40 65 104 143 391 -15.1 0.401 0.141 0.029

Descriptions of abbreviations and terms used in Table 1 are as follows.

E-SBR: emulsion polymerization styrene-butadiene rubber of Table 2 below

S-SBR1: solution polymerization styrene-butadiene rubber 1 of Table 2 below

S-SBR2: solution polymerization styrene-butadiene rubber 2 in Table 2

S-SBR3: solution polymerization styrene-butadiene rubber 3 in Table 2

BR: Butadiene Rubber

C / B: carbon black (N375)

SI: silica (ZEOSIL 115GR, Rhodia Silica Korea)

HD: Rubber Hardness (JIS)

300% MOD: Force per unit area at 300% elongation (kgf / ㎠)

TS: Tensile strength at break (kgf / ㎠)

EB: Elongation at Break (%)

T _g : Glass transition temperature (℃)

0 ° C. Tanδ: Dynamic viscoelastic properties at 0 ° C. Measured at 0 ° C. with 11 Hz, 1.25% strain using the Rheovibron Test.

70 ° C. Tanδ: Dynamic viscoelastic properties at 70 ° C. Measured at 70 ° C. with 11 Hz, 1.25% strain using the Rheovibron Test.

PICO: Pico abrasion test related to abrasion. Wear value (g) after 80 turns using B.F. Goodrich Abrasion Test

TABLE 2

Rubber type Styrene Content (wt%) Vinyl content (% by weight) Glass transition temperature (℃) Emulsion Polymerization Styrene-Butadiene Rubber 23.5 - -49 Solution-polymerized styrene-butadiene rubber 1 36 19 -30 Solution-polymerized styrene-butadiene rubber 2 21 51 -25 Solution-polymerized styrene-butadiene rubber 3 30 34 -30

Looking at Table 1, the tread rubber composition according to Examples 1 to 3 of the present invention showed a 0 ℃ Tanδ value similar to the rubber composition of Comparative Examples 1 to 3, 70 ℃ Tanδ lower than the rubber composition of Comparative Examples 1 to 3 Value and low PICO value, from this, the tread rubber composition according to Examples 1 to 3 of the present invention, compared with the rubber composition of Comparative Examples 1 to 3, improves the rolling resistance characteristics and wear resistance without a decrease in wet traction performance It was found.

As described above, according to the present invention, it is possible to obtain a tire tread rubber composition having improved rotational resistance characteristics and wear resistance without a decrease in wet traction performance.

Claims (2)

A tire tread rubber composition comprising 100 parts by weight of a raw material rubber containing 80% by weight or more of a solution-polymerized styrene-butadiene rubber having a vinyl content of 20 to 40% by weight, 30 to 70 parts by weight of silica, and 30 to 70 parts by weight of carbon black. The tire tread rubber composition according to claim 1, wherein the raw material rubber further comprises 20 wt% or less of natural rubber, butadiene rubber or emulsion polymerization styrene-butadiene rubber.