KR100738675B1 - Tire tread composition - Google Patents

Abstract

A tire tread composition is provided to improve wear performances of a tire by using wet masterbatch including raw material rubbers, silica, a silica coupling agent, oils, and carbon black. The tire tread composition comprises wet masterbatch containing 0.1-100phr of silica, 0.1-10phr of a silica coupling agent, 0.1-50phr of an aromatic oil, and 0.1-100phr of a carbon black based on 100phr of raw material rubbers. The silica serves as a reinforcing filler, has a surface area of 170±5 m^2/g and a moisture content of 6.0±0.5%, and contains at least 90% of carbon dioxide(SiO2). The carbon black has an iodine adsorption value of 90-120 mg/g and a DBP adsorption value of 130-140 cc/100g. The oil is an aromatic oil having a specific gravity of 0.95 or more and an aniline point of 60 or less.

Description

Tire tread composition {Tire tread composition}

The present invention relates to a rubber composition for tire treads, and more particularly, to a rubber composition for tire treads for passenger cars comprising a raw material rubber, silica, a silica coupling agent, and a composite prepared with oil and carbon black in a wet master batch.

In general, rubber has excellent affinity with carbon black and thus can be said to be easy to process, but it is difficult to satisfy wear, tension, and rolling resistance at the same time. In other words, improving wear through carbon black as a filler decreases rotational resistance, or improves traction, thereby exhibiting a trade-off relationship.

Silica is a representative filler proposed to improve the performance of the carbon black, and it is possible to secure the same level of wear performance as conventional carbon black while improving traction and rotational resistance at the same time. However, silica is characterized by hydrophilicity due to the OH group on the surface, there is a disadvantage in that dispersibility is very poor when combined with rubber. For this reason, since the silica-to-silica reaction is strong as a filler, the silica is blended. In order to improve the compounding performance of the silica, various methods have been proposed. The most representative one is to modify the surface of the hydroxyl group of the silica by applying a silane coupling agent. TESPT (Bis- (3-triethoxysilylpropyl)

Tetrasulfane) and TESPD (Bis- (3-ethoxysilylpropyl) disulfane) are examples of these, and these silane coupling agents are silanol groups that can react with silica and groups that can form chemical bonds with polymers during the vulcanization process. It consists of serves to increase the dispersibility of silica.

However, when the coupling agent is used, the ethoxy (EtO-Si) group at the end of the coupling agent first reacts with the silanol group (Si-OH) of the silica particles sufficiently, and the by-product ethanol (EtOH) is removed. The reaction should take place at 160 ° C. However, when the reaction conditions are higher than 170 ° C., the tetrasulfane group of the silane coupling agent may prematurely vulcanize. Therefore, much attention is required in the process of producing a rubber composition by applying a silica and a silane coupling agent.

Until now, the method mainly used in silica compound is used by mixing the silane coupling agent with carbon black by 50%, but this requires precise mixing conditions because of the difference in reaction depending on the process conditions as mentioned above. . This feature also causes many difficulties in implementing process automation.

For that reason, Korean Patent 2001-0081360 and Korean Patent 2003-0012103 were prepared by silica and wet master batch to improve dispersibility. However, the wet master batch process condition through the above technique shows the difference in recovery rate in the process of dispersing, agglomerating, and precipitating silica, and may indicate the quality distribution of semi-finished product (wet master batch composite). Will affect properties.

Therefore, the present invention improves the manufacturing processability by adding aromatic rubber or carbon black in the raw material rubber, silica, silica wet master process of the silane coupling agent, and finally improves the performance of the tire compound.

The present invention has been proposed to solve the problems of the prior art as described above, an object of the present invention is a tire for a passenger car comprising a composite prepared with a raw material rubber, silica, silica coupling agent, oil, carbon black in a wet master batch To improve the wear performance of the tire tread rubber composition.

In order to achieve the above object, the present invention includes a rubber composition including a wet master batch containing at least one of rubber, silica, and silane coupling agent in oil and carbon black in a rubber composition for tire tread.

In the above, the wet master batch comprises a rubber composition, characterized in that composed of 0.1 to 100 phr of silica, 0.1 to 10 phr of silane coupling agent, 0.1 to 50 phr of aromatic oil, and 0.1 to 100 phr of carbon black with respect to 100 phr of raw rubber.

Hereinafter, the present invention will be described in detail.

According to the present invention, rubber, silica, silane coupling agent, aromatic oil, and carbon black are prepared in a wet master batch, prepared as a composite, and applied to a tread compound of a tire to maintain basic rotational resistance and performance as a performance of a silica compound. In addition, the improvement of wear performance was improved by improving the process performance in composite manufacturing.

In addition, the present invention can be applied to the tire compound formulation after producing 0.1 to 100 phr of silica, 0.1 to 10 phr of silane coupling agent, 0.1 to 100 phr of carbon black, 0.1 to 50 phr of oil in a wet master batch phase with respect to 100 phr of raw rubber. have.

In the above, the raw rubber may be used alone or each of natural rubber or synthetic rubber.

The synthetic rubber is styrene butadiene rubber (SBR), butadiene rubber (BR), butyl rubber, epichlorohydrin rubber, nitrile rubber, hydrogenated nitrile rubber, BIMS (brominated polyisobutyl isoprene-co-paramethyl styrene), urethane rubber , Fluorine rubber, silicone rubber, SEBS, ethylene propylene rubber, EPDM rubber, hypalon rubber, chloroprene rubber, ethylene vinyl acetate rubber, acrylic rubber may be used.

In the present invention, when styrene butadiene rubber is used as the raw material rubber, styrene butadiene rubber having a styrene content of 23 ± 0.5% may be used.

Silica acts as a reinforcing filler and has a surface area of 170 ± 5㎡ / g, water content of 6.0 ± 0.5%, and silicon dioxide (SiO ₂ ) containing 90% or more, more preferably 97 ~ 99%. Ming refers to typical features and does not intend to limit the characteristics.

Carbon black preferably has an iodine adsorption value of 90 ~ 120mg / g and a DBP adsorption value of 130 ~ 140㏄ / 100g, it is preferable to use an aromatic oil having a specific gravity of 0.95 or more and an aniline point of 60 or less.

The wet master batch production may be prepared by stirring rubber and silica, a silane coupling agent, oil, and carbon black in a reaction tank prepared to enable water dispersion. After the preparation, the reactant is dehydrated through a coagulation process, made into a cake state, and then dried again to finally form a grinding process.

According to the present invention, in the rubber composition for tire tread, a wet master batch containing at least one of rubber, silica, and silane coupling agent among oil and carbon black is prepared and applied to a composite, thereby improving physical properties and wear resistance.

Hereinafter, the content of the present invention will be described in more detail with reference to Examples. However, these examples are only presented to understand the contents of the present invention, but the scope of the present invention is not limited to these embodiments.

Comparative Example 1

As a raw material rubber, styrene 23.5% styrene-butadiene rubber 100phr was applied, carbon black 50phr, silica phr, iodine adsorption value 115mg / g, DBP adsorption value 135cc / 100g, phrpt TESPT 4phr, aging 2 phr of inhibitor (TMDQ), 2 phr of silica dispersant (SDA), 2 phr of zinc oxide (ZnO), and 2 phr of stearic acid were added. Sulfur 2.0 phr and vulcanization accelerator (CZ) 2.0 phr were applied.

* TESPT: Bis- (3-triethoxysilylpropyl) tetrasulfane (coupling agent)

* SDA: Less than 5% Zinc soap, 95% or more Potassium soap, Fatty acids (silica dispersion agent)

* TMDQ: Polymerized 2,2,4-trimethyl-1,2-dihydroquinoline (Anti-aging agent)

* CZ: N-cyclohexyl-2-benzothiazol sulfonamide (vulcanization accelerator)

<Example 1>

As a raw material rubber, 100 phr of styrene-butadiene rubber latex with a styrene content of 23.5%, surface area of 175 ㎡ / g, water content of 6.5%, silica 50phr containing 97% of SiO ₂ , TESPT (Bis- ( 4-phr of 3-triethoxysilylpropyl) tetrasulfane) and 15 phr of aromatic oil were prepared in a wet master batch.

The wet master batch was prepared by stirring rubber and silica, a silane coupling agent, oil, and carbon black in a reactor prepared to disperse water. After the preparation, the reactant was dehydrated through a coagulation step to make a cake, dried again, and finally subjected to a grinding step.

After preparing the master batch, 15 phr of carbon black was added during compounding, 6 PPD 2 phr as anti-aging agent, 2 phr SDA as silica dispersant, 2 phr zinc oxide (ZnO), and 2 phr stearic acid were added. 2.0 phr, vulcanization accelerator CZ 2.0phr was applied.

<Example 2>

Carbon black is added in place of the aromatic oil during the wet master batch manufacturing process of Example 1, and the contents are as follows.

100 phr of 23.5% styrene-butadiene rubber latex containing styrene, surface area of 175 m 2 / g, water content of 6.5%, silica 50 phr containing 97% SiO ₂ , TESPT (Bis- (3-triethoxysilylpropyl) as silane coupling agent Tetrasulfane) was prepared in a wet master batch, 50 phr of carbon black having 4 phr, iodine adsorption value of 100 mg / g and DBP adsorption value of 130 kcal / 100 g. After preparing the masterbatch, 15 phr of aromatic oil was added in the compounding process, and 6PPD 2phr as an anti-aging agent, SDA 2phr, zinc oxide (ZnO) 2phr, and stearic acid 2phr were added as anti-aging agents. 2.0 phr, vulcanization accelerator CZ 2.0phr was applied.

<Example 3>

Aromatic oil and carbon black are simultaneously added during the wet master batch manufacturing process of Example 1, and the contents are as follows.

100 phr of styrene-containing 23.5% styrene-butadiene rubber latex, surface area of 175 ㎡ / g, water content of 6.5%, SiO ₂ more than 97% silica 50phr, TESPT (Bis- (3-triethoxysilylpropyl) as silane coupling agent 4 phr of tetrasulfane, 100 mg / g of iodine adsorption value and 130 ㏄ / 100 gram of DBP40 adsorption, was prepared in a wet master batch with 50 phr of aromatic black oil and 15 phr of aromatic oil. After preparing the masterbatch, 6PPD 2phr as an anti-aging agent, SDA 2phr, zinc oxide (ZnO) 2phr, stearic acid 2phr was added as an anti-aging agent, sulfur 2.0 phr, vulcanization accelerator CZ 2.0phr was applied as a vulcanizing system. .

Table 1 Rubber Compositions of Comparative Examples and Examples (phr)

division Comparative Example 1 (phr) Example 1 (phr) Example 2 (phr) Example 3 (phr) Composite 1 0 169 0 0 Composite 2 0 0 204 0 *** Composite 3 0 0 0 219 Styrene Butadiene Rubber 100 0 0 0 Silica 50 0 0 0 Silane coupling agent 4 0 0 0 Aromatic Oil 15 0 15 0 Carbon black 50 50 0 0 Silica dispersant 2 2 2 2 Anti-aging 2 2 2 2 Zinc oxide 2 2 2 2 Stearic acid 2 2 2 2 sulfur 2 2 2 2 Vulcanization accelerator 2 2 2 2

* Composite 1: composed of styrene butadiene rubber 100 phr, silica 50 phr, silane coupling agent 4 phr, aromatic oil 15 phr

** Composite 2: composed of styrene butadiene rubber 100 phr, silica 50 phr, silane coupling agent 4 phr, carbon black 50 phr

*** Composite 3: styrene butadiene rubber 100phr, silica 50phr, silane coupling agent 4phr, aromatic oil 15phr, carbon black 50phr

<Test Example 1>

The physical properties of the rubber composition according to the example and the results of the manufactured products are summarized in Table 2 below. As a result, when the aromatic master oil and carbon black were simultaneously included in the wet master batch manufacturing process, the tensile strength showed a synergistic effect of 15% compared to the comparative example and 11% improvement in the DIN wear index.

<Table 2> Comparative Example and Example Rubber Specimen Property Test Result

division Comparative example Example 1 Example 2 Example 3 Mooney Mooney viscosity t5 (min) 100 21 101 23 102 24 104 22 Properties Hardness 300% Modulus Tensile Strength Elongation 100 100 100 100 101 105 110 107 102 108 107 99 102 112 115 110 Wear DIN wear 100 106 108 111

※ The higher the wear index, the more favorable the value.

As described above, the present invention prepares a wet master batch containing at least one of raw material rubber, silica, and silane coupling agent in oil and carbon black in a rubber composition for tire tread, and applies it as a composite to improve physical properties and wear resistance. Indicates.

Claims (2)

delete In the rubber composition for tire tread, A rubber composition comprising a wet master batch containing 0.1 to 100 phr of silica, 0.1 to 10 phr of silane coupling agent, 0.1 to 50 phr of aromatic oil, and 0.1 to 100 phr of carbon black based on 100 phr of raw rubber.