KR101006713B1 - Rubber composition of tire tread - Google Patents

Abstract

The present invention relates to a rubber tread rubber composition, wherein the rubber tread rubber composition comprises a raw material rubber, a reinforcing filler, zinc oxide, stearic acid, a vulcanizing agent and a vulcanization accelerator. It is characterized by including nanodiamonds.

The rubber composition for a tire tread according to the present invention has an advantage of improving tensile strength, braking performance on a wet road surface, and improving fuel efficiency and abrasion resistance of a vehicle due to a reduction in tire rolling resistance.

Tire tread, rubber composition, nanodiamond

Description

Rubber composition for tire treads {RUBBER COMPOSITION OF TIRE TREAD}

The present invention relates to a rubber composition for tire treads, and more particularly, to a rubber composition which improves tensile strength, braking performance on wet roads, and improves fuel efficiency and wear resistance of a vehicle due to a reduction in tire rolling resistance. .

In accordance with recent eco-friendly policies, the development of low fuel economy tires by reducing tire rolling resistance and the development of tires with excellent wear resistance are the main concerns. To realize this, technologies using silica and eco-friendly fillers in tire tread rubber have been continuously developed. Is being developed.

Silica has been used as an environmentally friendly filler in tire tread rubber, and other examples include nanoclays, shell mills, and cellulose.

In the case of silica, since the surface chemical property is polar, it is not easy to disperse in non-polar rubber, which is disadvantageous in terms of processability. Thus, the use of a silane coupling agent solves this problem, and the silane coupling agent reacts with the silanol groups of the silica to change the polar surface chemical properties of the silica to non-polarity to facilitate mixing with rubber.

However, such a silane coupling agent is an expensive material and is disadvantageous in terms of cost, and there is a problem in that ethanol is generated when reacted with silica and volatilized during the process. In addition, fillers other than silica still suffer from disadvantages over silica or carbon black in terms of reinforcement of rubber.

Accordingly, it is an object of the present invention to provide a rubber composition for tire treads which has improved reinforcement and wear resistance of tread rubber by adding nanodiamonds as new fillers.

However, technical problems to be achieved by the present invention are not limited to the above-mentioned problems, and other technical problems will be clearly understood by the average technician from the following description.

In order to achieve the above object, the present invention is a rubber composition for tire tread comprising a raw material rubber, a reinforcing filler (filler), zinc oxide, stearic acid, a vulcanizing agent and a vulcanization accelerator, characterized in that it comprises nanodiamonds Provided is a rubber composition for tire treads.

The rubber composition for tire treads according to the present invention has the advantage of improving the tensile strength, braking performance on wet roads by adding nanodiamonds as a new filler, and improving the fuel efficiency and wear resistance of automobiles due to the reduction of tire rolling resistance. There is this.

In the present invention, by using nanodiamond and carbon black as a filler in the tire tread rubber composition, the rotational resistance is lower than that of the conventional carbon black alone, thereby improving automobile fuel efficiency and improving tire wear resistance.

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

The present invention provides a rubber composition for tire treads, comprising nanodiamonds, in a rubber composition for tire treads comprising a raw material rubber, a reinforcing filler, zinc oxide, stearic acid, a vulcanizing agent and a vulcanization accelerator.

The nanodiamond is contained in 5 to 30 parts by weight based on 100 parts by weight of the raw material rubber. When the content of the nanodiamond is less than 5 parts by weight, there is a problem that the reinforcing effect is insignificant, and when it exceeds 30 parts by weight, processing is difficult.

The raw material rubber may be a synthetic rubber, or a compound rubber made of a mixture of natural rubber and synthetic rubber. As the synthetic rubber, styrene-butadiene rubber, polyisoprene rubber, butadiene rubber, butyl rubber, halogenated rubber and ethylene-propylene rubber may be used, but is not limited thereto.

Examples of the reinforcing filler include carbon black and silica.

The carbon black is contained in 50 to 80 parts by weight based on 100 parts by weight of the raw material rubber. If the content of the carbon black is less than 50 parts by weight, there is a problem that the reinforcing effect is small, and if it exceeds 80 parts by weight, the heat generation is severe.

The silica is contained in 50 to 80 parts by weight based on 100 parts by weight of the raw material rubber. If the content of the silica is less than 50 parts by weight, there is a problem that the reinforcement is insignificant, and if it exceeds 80 parts by weight, the wear performance may be lowered.

The rubber composition according to the present invention comprises zinc oxide, stearic acid, a vulcanizing agent, a vulcanization accelerator, and an anti-aging agent.

The zinc oxide is used to activate the vulcanization reaction, and is included in an amount of 1 to 3 parts by weight based on 100 parts by weight of the raw material rubber.

The stearic acid is used for activation of the vulcanization reaction, it is included in 1 to 3 parts by weight based on 100 parts by weight of the raw material rubber.

The vulcanizing agent is used for the crosslinking of rubber, and is included in an amount of 1 to 5 parts by weight based on 100 parts by weight of the raw material rubber.

It is preferable to use a sulfur vulcanizing agent as the vulcanizing agent. Examples of the sulfur vulcanizing agent include vulcanizing agents for producing elemental sulfur or sulfur, such as amine disulfide and high molecular sulfur, and preferably elemental sulfur.

In addition, the vulcanization accelerator is used to promote the vulcanization reaction, and is included in an amount of 1 to 5 parts by weight based on 100 parts by weight of the raw material rubber.

The vulcanization accelerators include CBS, TBBS, DCBS, and the like.

On the other hand, the present invention, of course, in addition to the above-mentioned composition, various additives such as activators, processing oils, anti-aging agents, silane coupling agents and vulcanizing agents used in conventional tire tread compositions can be selected and used as necessary.

Hereinafter, preferred examples and comparative examples of the present invention are described. However, the following examples are only preferred embodiments of the present invention and the present invention is not limited to the following examples.

[Examples 1-3 and Comparative Example 1]

To prepare a tire rubber composition according to Examples 1 to 2 and Comparative Example 1 using the composition shown in Table 1. The tire rubber composition was produced by a conventional tire manufacturing method.

In the rubber compositions according to Examples 1 to 3 and Comparative Example 1, the raw material rubber was a mixed rubber of styrene-butadiene rubber and butadiene rubber.

The fillers used in Examples 1 to 3 were used together with carbon black and nanodiamonds.

In the rubber compositions according to Examples 1 to 3 and Comparative Example 1, 2 parts by weight of zinc oxide, 1 part by weight of stearic acid, 2 parts by weight of sulfur, and 1.8 parts by weight of vulcanization accelerator were used as other rubber compositions.

Example 1 Example 2 Example 3 Comparative Example 1 SBR ¹⁾ 123.75 123.75 123.75 123.75 BR ²⁾ 10 10 10 10 Carbon black ³⁾ 75 65 50 80 Nano Diamond 5 15 30 0 Zinc oxide ⁴⁾ 2 2 2 2 Stearic acid ⁵⁾ One One One One Sulfur ⁶⁾ 2 2 2 2 Vulcanization accelerator ⁷⁾ 1.8 1.8 1.8 1.8

(Unit: parts by weight)

Corporation

1) SBR1712 (LG Chemical)

2) BR 1208 (LG Chemistry)

3) HP1107 (Ebonic Carbon Black Korea)

4) Zinc Oxide (Hanil Chemical)

5) stearic acid (LG)

6) Ground sulfur (Miwon Corporation)

7) N-cyclohexyl-2-benzothiazylsulfenamide (Lanxess)

Various evaluation results of the rubber specimens prepared in Examples 1 to 3 and Comparative Example 1 are shown in Table 2 below, the measurement was in accordance with the following method.

(1) Mooney Viscosity (ML1 + 4, 125 ° C): A Mooney MV2000 (Alpha Technology) instrument was used to obtain a large rotor, preheating 1 minute, rotor operation time 4 minutes, and temperature 125 ° C.

(2) Tensile Properties: It was measured using an Instron tester according to ASTM D412 test method.

(3) Viscoelastic properties: Using a DMTS (Dynamic Material Testing System) tester was measured by temperature sweep from -60 ℃ to 80 ℃ under 10Hz, static strain 5%, dynamic strain 0.5% conditions. At this time, the higher the 0 [deg.] C tan δ value, the better the braking performance on the wet road surface, and the lower the 60 [deg.] C tan δ value, the lower the rotational resistance performance.

Example 1 Example 2 Example 3 Comparative Example 1 Miga
Properties ML1 + 4 (125 ° C) 63 63 64 62 Tensile Properties Hardness 67 69 72 65 100% Modulus (kgf / cm ² ) 27 30 34 26 300% modulus (kgf / cm ² ) 132 137 141 129 % Elongation 454 445 437 462 Tensile strength (kgf / cm ² ) 227 233 239 225 Viscoelastic
Properties 0 ℃ tan δ 0.453 0.461   0.482   0.454 60 ℃ tan δ 0.301 0.274 0.213   0.317 Wear Front (mm) 2.52 2.49 2.43 2.56 Rear (mm) 1.01 0.99 0.92 1.06

As shown in Table 2, in the case of Mooney viscosity, the specimens of Examples 1 to 3 using nanodiamond showed slightly higher values than the specimen of Comparative Example 1. Therefore, it can be said that the disadvantageous properties in view of the processability of the rubber.

In the case of tensile physical properties, the physical properties of Examples 1 to 3 show a general tendency to improve when compared with the physical properties of Comparative Example 1. This can be seen that in Examples 1 to 3, the reinforcement of the nanodiamonds is superior to that of carbon black, indicating higher tensile strength than Comparative Example 1. In addition, it can be seen that the tensile strength also increased as the amount of nanodiamonds increased.

In the case of viscoelastic properties, Examples 1 to 3 have the same level or higher 0 ° C tan δ value than that of Comparative Example 1, resulting in improved braking performance on wet road surfaces. In addition, in the case of Examples 1 to 3 has a lower 60 ℃ tan δ value than in the case of Comparative Example 1 can be sufficiently inferred that the rolling resistance of the tire will be lowered. This means that it can play a role of improving the fuel efficiency of the car by lowering the rolling resistance of the tire.

From the wear resistance performance, it can be seen that Examples 1 to 3 had less wear than those of Comparative Example 1. Therefore, it can be seen that the wear resistance is excellent in the tread to which nanodiamond is applied.

In summary, the use of nanodiamonds (Examples 1 to 3) tends to be more disadvantageous in terms of processability than when only carbon black is used. However, it has superior reinforcement than carbon black, resulting in higher tensile strength and braking on wet roads. Overall tire performance was improved, including performance, rolling resistance, and abrasion resistance.

All simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (6)

In a rubber composition for tire treads comprising a raw material rubber, a reinforcing filler, zinc oxide, stearic acid, a vulcanizing agent and a vulcanization accelerator, A tire composition for a tire tread comprising nanodiamond in an amount of 15 to 30 parts by weight based on 100 parts by weight of the raw material rubber. delete The rubber composition for a tire tread according to claim 1, wherein the reinforcing filler comprises at least one selected from the group consisting of carbon black and silica. The rubber composition for tire treads according to claim 3, wherein the carbon black is contained in an amount of 50 to 80 parts by weight based on 100 parts by weight of the raw material rubber. The rubber composition for tire treads according to claim 3, wherein the silica comprises 50 to 80 parts by weight based on 100 parts by weight of the raw rubber. A tire using the rubber composition according to any one of claims 1 and 3 to 5 for a tread.