KR100879462B1 - Rubber composition for tire tread - Google Patents

Abstract

A rubber composition for tire tread is provided to reduce the used amount of a silane coupling agent and to improve the low fuel efficiency of a compounded rubber while reducing the exhaust amount of hydrocarbon. A rubber composition for tire tread comprises a base rubber 100 parts by weight, silica 20-90 parts by weight as a reinforcing filler, a silane coupling agent 3-5 parts by weight, and a styrene - anhydrous maleic copolymer 1-20 parts by weight containing a repeating unit of the chemical formula 1. In the chemical formula 1, x is 1-5 and y is an integer of 2-10.

Description

Rubber composition for tire treads

The present invention relates to a rubber tread rubber composition, and more particularly, to a tire tread rubber composition which can improve the low fuel consumption characteristics of compounded rubber while reducing hydrocarbon emissions by using a small amount of silane coupling agent. .

In general, the technique of reducing the rolling resistance reduces the amount of reinforcing fillers, thereby reducing the interaction between the reinforcing agents, and thereby reducing the hysteresis loss, thereby improving the rolling resistance. However, this technique has a disadvantage in that braking performance and adjustment stability performance, which are important characteristics of the tire tread, are reduced as the amount of reinforcing filler is reduced.

And as another method to reduce the rolling resistance, a lot of efforts have been made to improve the interaction between carbon black and rubber, which is used as a reinforcing filler, but silica has been proposed as a solution to the carbon black due to its limitations. .

By using silica, properties such as low fuel consumption and braking performance of a tire can be improved simultaneously.

On the other hand, since silica is composed of a representative hydrophilic group, a hydroxyl group and a derivative thereof, it has little affinity with lipophilic rubber, which makes it difficult to disperse the filler during rubber compounding and the theoretical physical bonding force between the rubber and the filler is carbon. There is a limit to fall compared to black.

In order to solve this problem, the surface of silica should be lipophilic to improve affinity with rubber, and a silane coupling agent is typically used as the rubber compounding agent.

However, when the silane coupling agent is applied to a tire composition using silica as a filler, alcohol is formed by the reaction of the hydroxyl group on the silica surface with the alkoxyl group of the silane coupling agent. There was a problem that a large amount of material is produced.

On the other hand, as efforts to reduce volatiles in an environmentally friendly world are progressing in recent years, regulations on hydrocarbon emissions on tires have emerged, and the problem of reducing hydrocarbon emissions has emerged as an urgent problem to be solved in the tire industry.

The present invention was created to overcome the above problems, reducing the amount of silane coupling agent used, and generally using a styrene-maleic anhydride copolymer to increase the dispersibility of silica in the rubber, reducing hydrocarbon emissions It is an object of the present invention to provide a rubber tread composition for tire treads which can improve the low fuel consumption characteristics of compounded rubber.

Other objects and advantages of the invention will be described below and will be appreciated by the embodiments of the invention. Furthermore, the objects and advantages of the present invention can be realized by means and combinations indicated in the claims.

The rubber composition for tire treads according to the present invention includes a styrene-maleic anhydride copolymer comprising a raw material rubber and a reinforcing filler, a silica, a silane coupling agent, and a repeating unit represented by the following formula (1).

Here, x is 1-5, y is an integer of 1-10, and molecular weight is 2,000-20,000. Preferably y is an integer from 2 to 10.

The raw material rubber used as an example of the present invention is a diene-based polymer generally used in the rubber tread rubber composition, but is not necessarily limited thereto.

In addition, since the silica is used as the reinforcing filler, the content thereof is preferably used in an amount of 20 to 90 parts by weight based on 100 parts by weight of the raw material rubber.

In addition, when the styrene-maleic anhydride copolymer and the silane coupling agent are used simultaneously, the silane coupling agent is preferably included in an amount of 3 to 5 parts by weight based on 100 parts by weight of the raw material rubber.

When the content of the silane coupling agent is less than 3 parts by weight, the dispersion of silica is not smoothly performed, and the dispersibility is lowered. When the content of the silane coupling agent is more than 5 parts by weight, the effect of reducing hydrocarbon emissions may be insignificant.

The styrene-maleic anhydride copolymer including the repeating unit of Formula 1 may be used to reduce the emission of hydrocarbons and at the same time improve the low fuel consumption characteristics.

Specifically, since the y group representing the maleic anhydride portion of Chemical Formula 1 is chemically bonded by hydrogen bonding and ring-opening with silica, by-products are not generated, thereby reducing emissions of hydrocarbons.

The styrene-maleic anhydride copolymer having a role as described above includes 1 to 20 parts by weight based on 100 parts by weight of the raw material rubber. If the content is less than 1 part by weight based on 100 parts by weight of the raw material rubber, the effect of the addition. If it is insignificant and exceeds 20 parts by weight, there may be a problem of lowering the mechanical properties of the blended rubber.

Of course, the present invention may include sulfur, a vulcanizing agent, zinc oxide, stearic acid, a vulcanizing agent, and an aromatic oil, a vulcanization accelerator, and an anti-aging agent as a softener.

The terms or words used in this specification and claims are not to be construed as being limited to their ordinary or dictionary meanings, and the inventors may appropriately define the concept of terms in order to best describe their invention. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that the present invention.

Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

The rubber composition for tire treads according to the present invention as described above provides the following effects.

The amount of silane coupling agent used can be reduced, and styrene-maleic anhydride copolymers can be generally used to increase the dispersibility of silica in rubber, reduce hydrocarbon emissions and improve the low fuel consumption characteristics of the compounded rubber.

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

Example  And Comparative example

The rubber composition was prepared by releasing the compounding agent in a half-barrier mixer at the temperature of 150 ° C. in the composition as shown in [Table 1].

Table 1

In Table 1, the silane coupling agent contained sulfur in the molecular structure, so that a slight amount of sulfur was increased in the Examples compared to the Comparative Example for the application of the styrene-maleic anhydride copolymer containing no sulfur.

The physical properties of the rubber specimens obtained according to the comparative examples and examples are shown in [Table 2], where the wear index is the rambon abrasion ratio and the loss amount of the worn rubber was rotated at a sliding ratio of 25% and a load of 1.5 kg at room temperature. The value indicated as 100 indicates that the higher the value, the better the wear performance.

* Wear Index = ( wear amount of comparative example / wear amount of example ) × 100

0 ° C Tan δ is a measure of wet road braking performance, which means that the higher the value, the better. 60 ° C Tan δ is a measure of rotational resistance at 60 ° C.

Hydrocarbon emissions were stored for a certain amount of vulcanized compound rubber specimens at 160 ° C for a certain period of time, and collected and volatilized. The lower the value, the lower the hydrocarbon emissions.

* Hydrocarbon emissions Index = (embodiment Volatile Concentration / Comparative Example Volatility Concentration) × 100

Table 2

As can be seen from the above [Table 2] Examples 1 to 4 can be seen that the hydrocarbon emissions, wear, and 60 ℃ tan δ is superior to the comparative example.

As described in detail above, the introduction of a styrene-maleic anhydride copolymer while using silica as a reinforcing agent according to the present invention can reduce the amount of silane coupling agent used and hydrocarbon emission and at the same time improve the low fuel consumption characteristics of the compounded rubber. It is useful for tread compositions because it can

Claims (2)

100 parts by weight of raw rubber; 20 to 90 parts by weight of silica as a reinforcing filler; 3 to 5 parts by weight of a silane coupling agent; And A rubber composition for a tire tread comprising 1 to 20 parts by weight of a styrene-maleic anhydride copolymer including a repeating unit represented by Formula 1 below. Formula 1

Here, x is 1-5, y is an integer of 2-10, and a weight average molecular weight is 2,000-20,000. delete