KR101683989B1 - Tire Tread Rubber Composition having Improved Fuel Efficiency and Braking Property - Google Patents

Abstract

The present invention relates to a tire tread rubber composition having improved braking performance and fuel economy. More particularly, the present invention relates to a tire tread rubber composition comprising styrene-butadiene rubber (SBR), butyl rubber (IIR) and natural rubber To a tire tread rubber composition which contains silica and aluminum hydroxide as fillers at a predetermined content ratio and improves not only wear resistance but also braking performance and fuel consumption performance.

Description

[0001] The present invention relates to a tire tread rubber composition having improved braking performance and fuel economy,

The present invention relates to a tire tread rubber composition having improved braking performance and fuel economy. More particularly, the present invention relates to a tire tread rubber composition comprising styrene-butadiene rubber (SBR), butyl rubber (IIR) and natural rubber To a tire tread rubber composition which contains silica and aluminum hydroxide as fillers at a predetermined content ratio, thereby improving not only wear resistance but also braking performance and fuel consumption performance.

Recent trends in the development of the tire industry have been studied for the production of products with low fuel consumption, low rolling resistance, and environmentally friendly materials. Particularly, efforts have been actively made to improve both the fuel consumption performance and the braking performance of the tire at the same time, but it is difficult to improve the low fuel consumption performance and the braking performance simultaneously with the rubber composition. So, instead of improving the performance of one of the two capabilities, research has been conducted at a level that keeps the other performance equal. As a conventional method, there is a method of applying a rubber synthesized by an emulsion polymerization method in order to improve a rotational resistance performance, and a method of using a silica reinforcing agent is generally applied to improve a low fuel consumption performance.

Korean Patent No. 10-578096 discloses a technique of kneading 50 parts by weight of silica and 30 parts by weight of aluminum hydroxide (Al (OH) ₃ ) in 100 parts by weight of SBR rubber in order to simultaneously improve the fuel efficiency and braking performance on a wet road surface However, the abrasion resistance and the processability are poor due to the rubber composition limitations, so that it can not be practically applied to the tire industry.

Most of the silica compounded rubber compositions reported so far do not consider the abrasion resistance, which is one of the main characteristics of the tire, which is the greatest weakness of the silica rubber compound. Generally, butyl rubber (IIR) is added to improve abrasion resistance, but in this case, there is a disadvantage that the braking performance on a wet road surface is deteriorated. In addition, although the abrasion resistance can be improved by increasing the weight of silica, this method has a disadvantage in that the workability is poor.

Therefore, in the present invention, the optimal combination of silica, aluminum (IIR) and natural rubber (NR) ensures that sufficient abrasion resistance can be applied to the tire through the optimum combination of SBR rubber, butyl rubber The present invention has been completed.

Korean Patent No. 10-578096

An object of the present invention is to provide an improved tire tread rubber composition having sufficient wear resistance applicable to tires and simultaneously improving fuel consumption performance and braking performance.

In order to solve the above problems, the present invention provides a rubber composition comprising 60 to 80 wt% of SBR rubber, 5 to 20 wt% of butyl rubber (IIR) and 5 to 20 wt% of natural rubber (NR) 50 to 60 parts by weight of silica and 10 to 20 parts by weight of aluminum hydroxide are contained based on parts by weight.

The present invention also provides a tire tread comprising the above rubber composition.

The rubber composition of the present invention has an effect of ensuring sufficient abrasion resistance that can be applied to a tire through optimal compounding of SBR rubber, butyl rubber (IIR) and natural rubber (NR).

Also, the rubber composition of the present invention has the disadvantage that the blooming on the wet road surface is weakened due to the inclusion of the butyl rubber (IIR), and the filler of the silica and the aluminum hydroxide is contained at an appropriate ratio.

Therefore, the rubber composition of the present invention is excellent in abrasion resistance, braking performance, and fuel consumption performance, and thus is useful as a tire tread material for a vehicle.

The present invention relates to a tire tread rubber composition, which comprises SBR rubber, butyl rubber (IIR) and natural rubber (NR) as rubber components, and silica and aluminum hydroxide as filler components.

Each component constituting the tire tread rubber composition according to the present invention will be described in more detail as follows.

In the present invention, SBR rubber, butyl rubber (IIR) and natural rubber (NR) are included as rubber components.

As mentioned in the above-mentioned prior art, there have been attempts to improve both fuel efficiency and braking performance by incorporating silica and aluminum hydroxide as fillers in the SBR rubber. However, due to the inherent nature of the rubber material, the abrasion resistance and workability are poor, It was impossible to apply it.

In the present invention, SBR rubber, butyl rubber (IIR) and natural rubber (NR) are mixed and used as a rubber component in order to improve abrasion resistance which is the weakest point of the silica compounded rubber composition. Specifically, the tire tread rubber composition according to the present invention contains 60 to 80% by weight of SBR rubber, 5 to 20% by weight of butyl rubber (IIR) and 5 to 20% by weight of natural rubber (NR) as rubber components.

When the content of the SBR rubber as the rubber component constituting the tire tread rubber composition of the present invention is less than 60% by weight, the abrasion performance is lowered. If the content of butyl rubber (IIR) is less than 5% by weight, excellent tire braking characteristics can not be expected. If it exceeds 20% by weight, abrasion performance and mechanical properties may be deteriorated. If the content of the natural rubber (NR) exceeds 20% by weight, the braking performance may be deteriorated.

In the present invention, silica and aluminum hydroxide are included as filler components.

As mentioned in the above-mentioned prior art, there has been an effort to improve the fuel consumption performance and the braking performance by kneading silica and aluminum hydroxide as fillers in the SBR rubber. However, as in the present invention, SBR rubber, butyl rubber (IIR) (NR) is kneaded with silica and aluminum hydroxide has not been reported so far. In other words, since the rubber component of the present invention further contains a butyl rubber (IIR) and a natural rubber (NR) in addition to the SBR rubber, it is very important to select the filler and adjust its content to the rubber composition.

In the present invention, 50 to 60 parts by weight of silica and 10 to 20 parts by weight of aluminum hydroxide are kneaded, based on 100 parts by weight of a rubber component having SBR rubber, butyl rubber (IIR) and natural rubber (NR) Feature.

If the content of silica as the filler component constituting the tire tread rubber composition of the present invention is less than 50 parts by weight, the wet braking performance and the wear performance may be lowered. If the content of aluminum hydroxide is less than 10 parts by weight, the effect of improving the wet braking performance is small, and if it exceeds 20 parts by weight, the fuel consumption performance is greatly deteriorated.

The tire tread rubber composition according to the present invention may contain various additives such as active agents, antioxidants, process oils, vulcanizing agents and vulcanization accelerators, which are conventionally used for producing tire tread rubber, in addition to the above- If desired, it can be used in a predetermined amount by selecting the enemy. These additives are general components used in the production of conventional tire tread rubber compositions, and the present invention is not particularly limited to these components and content ratios.

As described above, the rubber composition of the present invention comprising the rubber component and the filler component of a specific composition has both the low performance and the braking performance while securing the wear resistance required as the tire tread, Are also included in the scope of the present invention. That is, the present invention includes tires for passenger cars, tires for trucks, and tires for buses manufactured using the rubber composition.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited by the following examples.

[Example]

Examples 1 to 2 and Comparative Examples 1 to 7. Manufacture of tire tread rubber composition

A rubber component, a filler component, and a processing aid conventionally used in the production of a tire rubber were kneaded in a mixer according to the components and amounts shown in Table 1 below. After that, a vulcanizing agent, vulcanization auxiliary agent and the like were added and vulcanized by a usual method to prepare a tire tread rubber.

division Tire tread rubber composition (parts by weight) Example Comparative Example One 2 One 2 3 4 5 6 7
Rubber SBR 70 70 100 100 100 100 70 70 70 IIR 15 15 0 0 0 0 30 0 15 NR 15 15 0 0 0 0 0 30 15
filler Silica 60 50 70 60 50 40 70 70 70 Hydroxide
aluminum 10 20 0 10 20 30 0 0 0

Experimental Example: Measurement of physical properties of rubber specimens

The properties of the rubbers prepared in Examples 1 to 2 and Comparative Examples 1 to 7 were measured by the following methods. The results are shown in Table 2 below.

[Measurement of physical properties]

(1) Hardness: The hardness value is measured by using a shore-A hardness meter. The hardness value is indicated by an index. The lower the value, the lower the hardness.

(2) Wear Index: The abrasion resistance was evaluated by using a rambone abrasion tester (Ueshima, Japan). The wear rate was evaluated at a slip rate of 5% and a load of 20 N at 23 ° C for 2 hours. Volume and relative abrasion index for comparison.

(3) Tensile strength and elongation: The tensile strength was evaluated by using a dumbbell specimen. The stress-strain curve was measured at 25 ° C using a tensile tester at a tensile speed of 500 mm / min and a load cell of 500 kgf Respectively.

(4) Dynamic characteristics: Dynamic mechanical thermal analysis (DMTA) was used to measure the mechanical modulus of the material with respect to temperature, frequency and vibration, and the ratio of the storage modulus to the loss modulus was quantified. A static strain of 3%, a dynamic strain of 0.25% and a frequency of 11 Hz were measured at a temperature of -80 to 100 ° C (temperature rise rate of 2 ° C / min), and a specimen of 2 (T) * 5 .

(5) Friction Coefficient: The friction coefficient was measured at 30 Km / h and 70 N using a dynamic friction tester (Roataing Traction Measurement Machine).

division goal
Property value Example Comparative Example One 2 One 2 3 4 5 6 7 Hardness 60
More than 68 66 70 68 66 64 70 70 70 Wear index
(index) 90
More than 94 90 100 95 84 79 95 95 95 The tensile strength
(kg / cm2) 180
More than 188 185 190 185 181 168 183 204 193 Elongation (%) 400
More than 410 403 413 400 395 363 380 428 405 tanδ @ 0 C
(Wet braking) 0.51
More than 0.552 0.567 0.465 0.487 0.492 0.508 0.574 0.512 0.535 tanδ @ 25 ℃
(Dry braking) 0.23
More than 0.265 0.273 0.212 0.231 0.238 0.244 0.278 0.241 0.253 tanδ @ 60 ° C
(Fuel efficiency performance) 0.10
Below 0.125 0.120 0.119 0.115 0.110 0.105 0.152 0.135 0.145
friction
Coefficient Wet 1.40
More than 1.408 1.405 1.382 1.374 1.366 1.348 1.401 1.394 1.409 dry 1.53
More than 1.550 1.547 1.539 1.521 1.511 1.496 1.552 1.540 1.555

As shown in Table 2, the rubber specimens (Examples 1 and 2) in which silica and aluminum hydroxide were kneaded as a filler in a rubber component containing SBR rubber, butyl rubber (IIR) and natural rubber (NR) exhibited abrasion resistance, Performance, and braking performance are all excellent.

On the other hand, in Comparative Examples 1 to 4, it was confirmed that SBR alone was used as the rubber component and silica alone or silica and aluminum hydroxide were kneaded as the filler, indicating low wear resistance. In addition, in the conventional invention, silica and aluminum hydroxide were added to SBR rubber to improve both the braking performance and the fuel consumption performance. However, according to the results of the tests of Comparative Examples 1 to 4, there is still room for improvement in braking performance and fuel consumption performance Can be confirmed.

Comparative Examples 5 to 7 were rubber compositions prepared by kneading silica alone as a filler in a rubber component containing an SBR rubber and a butyl rubber (IIR) and / or a natural rubber (NR). The wear resistance was improved to some extent, It can be confirmed that it is poor.

Claims (4)

A rubber component containing 60 to 80% by weight of an SBR rubber, 5 to 20% by weight of a butyl rubber (IIR) and 5 to 20% by weight of a natural rubber (NR)
50 to 60 parts by weight of silica and 10 to 20 parts by weight of aluminum hydroxide are contained based on 100 parts by weight of the rubber component.
A tire tread comprising the rubber composition of claim 1.
A tire comprising the tire tread of claim 2.
The method of claim 3,
A tire applied to a vehicle selected from the group consisting of passenger cars, trucks and buses.