KR101938993B1 - Rubber composition for tire tread and tire manufactured by using the same - Google Patents

Abstract

The present invention relates to a rubber composition for a tire tread comprising 100 parts by weight of material rubber, 70-120 parts by weight of a reinforcement filling material, and 10-50 parts by weight of oil extracted from microalgae, and a tire manufactured by using the same. Therefore, an energy loss caused by rolling resistance of the tire is reduced to increase fuel efficiency of a vehicle and reduce a discharge amount of an environmental pollution material.

Description

TECHNICAL FIELD [0001] The present invention relates to a rubber composition for a tire tread, and a tire produced using the same. BACKGROUND OF THE INVENTION [0002]

TECHNICAL FIELD The present invention relates to a rubber composition for a tire tread which is environmentally friendly and can improve the fuel economy of a vehicle, and a tire manufactured using the same.

The United Nations Framework Convention on Climate Change (UNFCCC) adopted the International Convention for the Regulation and Prevention of Global Warming, the UN Framework Convention on Climate Change Since then, we have been working hard to solve environmental problems around the world.

To reduce greenhouse gas emissions including carbon dioxide (CO ₂ ) emissions, the automobile industry has been launching hybrid cars and electric vehicles to improve fuel efficiency and reduce pollutants emissions. New electric car manufacturers are emerging, not car makers. In the tire industry, various efforts have been made to increase the fuel efficiency of the vehicle by reducing the energy loss due to the rolling resistance of the tires generated during the running of the vehicle.

Since 2012, labeling system for tires has been implemented throughout the world, starting with Europe (EU), indicating the rating for wet traction, rolling resistance, and noise on wet roads. In addition, not only domestic but also Japanese and North American markets have been implementing their energy efficiency rating schemes in accordance with such global trends.

In the tire industry, focusing on product label development performance, it is expected that there will be trade-off tendency that different performance is disadvantageous to improve one performance, Wear performance, snow performance that determines winter braking and handling performance, and endurance performance that determines the long-term stability of the tire.

In the European market, the tire industry is divided into summer tires and winter tires. In North America and Korea, all-season tires are the main sales market. In recent years, with the development of the North American market in the environment that was differentiated from the summer and winter, it is gradually becoming a seasonal tire. Since the four-season tires are used without tires in summer as well as winter, they are required to have braking performance on the wet road surface, wear performance, and braking performance on the ice and snow surface. However, such wet road surface braking performance and wear performance and braking performance on snow and ice road surface are opposite to each other. Increasing the compound transition temperature (Tg) or increasing the reinforcing agent content to improve the braking performance on the wet road surface improves the mechanical properties of the rubber compound, but decreases the braking performance on the ice and snow surface.

The operating temperature range of a typical tire is -20 ° C to 40 ° C, and the operating temperature range is wide. However, this is because the synthetic oil used for facilitating the processing of the rubber can be eluted from the tread in the high-temperature asphalt which goes up to 40 ° C in the middle of the summer, and eventually changes the elastic properties of the rubber, It is recognized as a risk factor for driving stability. In particular, in a tire having a filler content of 100 phr or more, a synthetic oil content is inevitably used in order to secure the mixing stability of the rubber, which adversely affects the long-term durability and aging characteristics of the tire.

 As a technology for using an environmentally friendly raw material for tires, silica, which is most recently used, is a representative example instead of carbon black obtained from petroleum raw materials. There are other techniques to synthesize polyisoprene by using butadiene extracted from environmentally friendly raw materials. However, there is a processing oil which is the most commonly used next to rubber and reinforcing filler. Most of the raw materials used as processing oil are petroleum oil. Recently, most of the researches applied to tire tread compound using natural oil have been made. Among them, oleic acid and linoleic acid are extracted and separated from natural oil selected from the group consisting of sunflower seed oil, soybean oil, cottonseed oil, canola oil, palm oil, grape seed oil, .

 However, using this first-generation biomass, natural oil, is considered to increase the problem of food conflicts and the total amount of carbon dioxide in the earth in the process of expanding the area of cultivated land. Second-generation biomass is difficult to apply to the tire industry due to its slow growth and difficulty in degrading cellulosic wood. On the other hand, micro-algae or giant algae, called third generation biomass, is attracting attention as a resource that can not be put to practical use if economical efficiency is secured. Currently, research power is concentrated around the world. In particular, research and development are being perceived as a more important resource in the domestic situation where the three-sided sea can utilize the location conditions.

An object of the present invention is to provide a rubber composition for a tire tread which can reduce energy loss due to rolling resistance of a tire to increase the fuel economy of a vehicle and reduce the amount of environmental pollutants emitted.

Another object of the present invention is to provide a tire produced by using the rubber composition for a tire tread.

The present invention provides a rubber composition for a tire tread comprising 100 parts by weight of a raw material rubber, 70 to 120 parts by weight of a reinforcing filler, and 10 to 50 parts by weight of an oil extracted from microalgae.

The raw material rubber may contain 5 to 10% by weight of natural rubber, 40 to 70% by weight of solution-polymerized styrene-butadiene rubber and 20 to 50% by weight of butadiene rubber based on the total weight of the raw material rubber.

The solution-polymerized styrene-butadiene rubber has a styrene content of 20 to 50% by weight, a vinyl content of 10 to 40% by weight, and further contains 20 to 40 parts by weight of SRAE oil per 100 parts by weight of the solution- , The glass transition temperature is -50 to -20 占 폚, the butadiene rubber has a cis-1,4-butadiene content of 95 to 100% by weight and a glass transition temperature of -120 to -100 占 폚.

Wherein the reinforcing filler comprises 65 to 100 parts by weight of silica and 5 to 20 parts by weight of carbon black with respect to 100 parts by weight of the raw rubber and the silica has a nitrogen adsorption specific surface area of 160 to 180 m 2 / g, a CTAB value of 150 to 170 M 2 / g and a DBP oil absorption of 180 to 200 cc / 100 g. The carbon black may have a nitrogen adsorption specific surface area of 30 to 300 m 2 / g and a DBP oil absorption of 60 to 180 cc / 100 g.

The oils extracted from the microalgae may be selected from the group consisting of Aurantiochytrium , Schizochytrium , Thraustochytrium , Japonochytrium , UIkenia , And may be extracted from any microalgae selected from the group consisting of Crypthecodinium genus, Haliphthoros genus, Isochrysis genus, and mixtures thereof.

Wherein the oil extracted from the microalgae contains 35 to 40% by weight of palmitic acid, 0.5 to 1.5% by weight of stearic acid, and oleic acid based on the total weight of the oil extracted from the microalgae. 0.5 to 1.5% by weight of linoleic acid, 1.5 to 2.5% by weight of linoleic acid, 0.5 to 1.5% by weight of eicosapentaenoic acid (EPA), 10 to 15% by weight of docosapentaenoic acid (DPA) , And 40 to 45 wt% of docosahexaenoic acid (DHA).

The oil extracted from the microalgae may be extracted using any one solvent selected from the group consisting of hexane, methanol, ethanol, petroleum ether, chloroform, and mixtures thereof.

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The present invention also provides a tire manufactured using the rubber composition for a tire tread.

The rubber composition for a tire tread according to the present invention and a tire manufactured using the same can reduce the energy loss due to the rolling resistance of the tire, thereby increasing the fuel economy of the vehicle and reducing the amount of environmental pollutants discharged.

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

The present invention provides a rubber composition for a tire tread comprising 100 parts by weight of a raw material rubber, 70 to 120 parts by weight of a reinforcing filler, and 10 to 50 parts by weight of an oil extracted from microalgae.

The raw material rubber may include natural rubber, solution-polymerized styrene-butadiene rubber, and butadiene rubber.

The natural rubber may be a general natural rubber or a modified natural rubber.

The above-mentioned general natural rubber may be used as long as it is known as natural rubber, and the country of origin and the like are not limited. The natural rubber includes cis-1,4-polyisoprene as a main component, but may also include trans-1,4-polyisoprene depending on required characteristics. Therefore, in addition to natural rubber containing cis-1,4-polyisoprene as a main component, natural rubber including trans-1,4-isoprene as a main component, such as balata, Rubber may also be included.

The natural rubber may be included in an amount of 5 to 10% by weight, and more preferably 5 to 10% by weight based on the total weight of the raw rubber. When the natural rubber is contained in an amount of less than 5% by weight, the inherent characteristics of the natural rubber having a crystallized structure are insignificant, and if it exceeds 15% by weight, an adverse problem may occur in terms of compatibility with the synthetic rubber.

The solution-polymerized styrene-butadiene rubber used at the same time has a styrene content of 20 to 50% by weight, a vinyl content of 10 to 40% by weight, an SRAE oil in an amount of 20 to 40 wt% based on 100 parts by weight of the solution- And the glass transition temperature is preferably -50 to -20 占 폚.

When the styrene-butadiene rubber having the above characteristics is used, the hysteresis of the tire tread becomes high, so that the braking performance on a dry or wet surface can be simultaneously improved.

The weight average molecular weight (Mw) of the solution-polymerized styrene-butadiene rubber may be 1,200,000 to 1,700,000 g / mol, and the molecular weight distribution is 1.5 or more, which results in excellent workability due to a broad molecular weight distribution and high molecular weight, .

The solution-polymerized styrene-butadiene rubber may be 40 to 70% by weight based on the total weight of the raw material rubber. When the amount of the styrene-butadiene rubber is out of the range, both the braking performance and the wear resistance performance of the wet road surface and the icy and snow surface may be increased or decreased.

As another raw material rubber used, there is a butadiene rubber (BR), the butadiene rubber may have a cis-1,4-butadiene content of 95 to 100% by weight and a glass transition temperature of -120 to -100 ° C .

The butadiene rubber (Nd-BR) may be contained in an amount of 20 wt% to 50 wt% with respect to the total weight of the raw rubber. If the weight of the butadiene rubber is less than 20% by weight, abrasion resistance and low fuel consumption performance are disadvantageous. If the weight is more than 50% by weight, workability may be deteriorated.

The reinforcing filler used in the present invention is preferably a mixture of silica and carbon black. In addition, a silane coupling agent may be further used to improve the dispersibility of silica.

The reinforcing filler may be included in an amount of 75 to 120 parts by weight based on 100 parts by weight of the raw rubber. Specifically, the silica is preferably used in an amount of 70 to 100 parts by weight based on 100 parts by weight of the starting rubber. When the amount of the silica is less than 70 parts by weight, there is a problem that the braking performance is poor. When the amount of the silica is more than 110 parts by weight, abrasion resistance and low fuel consumption performance are disadvantageous.

In addition, the carbon black may contain 5 to 20 parts by weight based on 100 parts by weight of the raw rubber. When the carbon black is included in an amount of less than 5 parts by weight, the reinforcing effect is insignificant. When the carbon black is more than 20 parts by weight, And a decrease in braking performance on the ice and snow road surface due to excessive reinforcement.

The silica is a highly disperse silica having a nitrogen adsorption specific surface area of 160 to 180 m 2 / g, a CTAB value of 150 to 170 m 2 / g and a DBP oil absorption of 180 to 200 cc / 100 g in order to obtain a tread rubber composition suitable for the purpose of the present invention desirable.

The silane coupling agent includes bis (trialkoxysilylpropyl) polysulfide (TESPD) and bis-3-triethoxysilylpropyltetrasulfide (TESPT) in an alkoxy polysulfide silane compound. TESPD is a mixture of TESPT and carbon black 50 %. The silane coupling agent is preferably used in an amount of 10 to 20 parts by weight based on 100 parts by weight of the raw material rubber.

The carbon black may have a nitrogen surface area per gram (N 2 SA) of 30 to 300 m 2 / g and an oil absorption of DBP (n-dibutyl phthalate) of 60 to 180 cc / 100 g, But is not limited thereto.

If the nitrogen adsorption specific surface area of the carbon black exceeds 30 m 2 / g, the workability of the rubber composition for a tire may be deteriorated. If it is less than 30 m 2 / g, the reinforcing performance by carbon black as a filler may be deteriorated. If the DBP oil absorption of the carbon black exceeds 180 cc / 100 g, the workability of the rubber composition may deteriorate. If the DBP oil absorption is less than 60 cc / 100 g, the reinforcing performance of carbon black as a filler may be deteriorated.

Examples of the carbon black include N110, N121, N134, N220, N231, N234, N242, N293, N299, S315, N326, N330, N332, N339, N343, N347, N351, N358, N375, N539, , N630, N642, N650, N683, N754, N762, N765, N774, N787, N907, N908, N990 or N991.

A rubber composition for a typical tire tread may further comprise a softening agent together with the reinforcing filler. The rubber composition for a tire tread according to the present invention is characterized by further comprising an oil as a lipid component extracted from the microalgae with the softening agent.

The oil extracted from the microalgae is environment-friendly unlike the petroleum-based processed oil used as a general softener, and has an advantage that it is easier to cultivate and harvest than the vegetable oil. Specifically, vegetable oils such as sunflower seed oil and soybean oil require considerably longer cultivation period and cultivated area. On the other hand, the oil extracted from the microalgae according to the present invention grows rapidly from cultivation to harvest until about a week, It is possible to produce using existing microbial fermentation facilities without having to prepare cultivation area.

The oil extracted from the microalgae has a long carbon number, but has a large number of double bonds. In addition, it has plasticity imparted to the rubber composition to facilitate processing and lower the hardness of the vulcanized rubber, Due to low viscosity and structural difference compared to existing petroleum oils, it is possible to improve fuel economy by reducing energy loss due to tire rolling resistance by improving silica dispersibility in the compound.

Most preferably, the rubber composition for a tire tread according to the present invention contains 10 to 50 parts by weight of an oil extracted from the microalgae.

The microalgae are not limited as long as they have a long carbon number but can form an oil having a polyunsaturated fatty acid (PUFA) structure having a large number of double bonds.

The microalgae are specifically exemplified by those belonging to the genus Aurantiochytrium , the genus Schizochytrium , the genus Thraustochytrium , the genus Japonochytrium , the genus Ulkenia , Crypthecodinium genus, Haliphthoros genus, Isochrysis genus, and mixtures thereof.

The oil component obtained by extracting the microalgae may be a polyunsaturated fatty acid having 16 to 22 carbon atoms. Specifically, the oil extracted from the microalgae may be omega-3 unsaturated fatty acid, omega-6 unsaturated fatty acid, palmitic acid ), Stearic acid, and a combination of these.

More specifically, the oil extracted from the microalgae contains 35 to 40% by weight of palmitic acid, 0.5 to 1.5% by weight of stearic acid, oleic acid ( 0.5 to 1.5% by weight of oleic acid, 1.5 to 2.5% by weight of linoleic acid, 0.5 to 1.5% by weight of eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) 10 to 15% by weight, and 40 to 45% by weight of docosahexaenoic acid (DHA).

The oil extracted from the microalgae may be prepared by microalgae culture, microalgae harvest-concentration, and microalgae extraction.

In the microalgae culture step, microalgae may be grown using glucose or the like obtained from photosynthesis or photosynthesis as a carbon source.

The step of harvesting and concentrating the microalgae may include culturing the cultured microalgae using centrifugation, gravity precipitation, flocculation, electrolysis, floatation, and electrophoresis.

The microalgae extracting step may be carried out by using microalgae in a dry or wet state and performing a chemical method such as a solvent extraction method, a mechanical method such as an oil pressing method or a supercritical carbon dioxide gas extraction method, or a combination of the two methods.

The solvent may be any one selected from the group consisting of hexane, methanol, ethanol, petroleum ether, chloroform, and mixtures thereof.

The rubber composition for a tire tread may further include various additives such as an additional vulcanizing agent, a vulcanization accelerator, a vulcanization accelerator, and an anti-aging agent. The various additives can be used as long as they are commonly used in the field to which the present invention belongs. The content thereof is not particularly limited as long as it depends on a compounding ratio used in a rubber composition for a tire tread.

However, a compound drop due to a large amount of double bonds contained in the oil extracted from the microalgae may occur. In the present invention, the above problems can be solved by optimizing the content of the sulfur vulcanizing agent and the content of the vulcanization promoting auxiliary. The content of the sulfur vulcanizing agent is 0.75 to 1 part by weight to improve the low fuel consumption characteristic and the vulcanization accelerator auxiliary is included in the amount of 2.5 to 5 parts by weight to improve the mechanical properties and the braking performance.

As the vulcanizing agent, a sulfur vulcanizing agent can be preferably used. The sulfur vulcanizing agent is an inorganic vulcanizing agent such as powder sulfur (S), insoluble sulfur (S), precipitated sulfur (S), colloid sulfur, etc., tetramethylthiuram disulfide (TMTD) Organic vulcanizing agents such as tetraethyltriuram disulfide (TETD) and dithiodimorpholine can be used. As the sulfur vulcanizing agent, a vulcanizing agent which produces elemental sulfur or sulfur, for example, amine disulfide, polymer sulfur and the like can be used.

It is preferable that the vulcanizing agent is included in an amount of 0.75 to 1 part by weight based on 100 parts by weight of the raw material rubber from the viewpoint that the raw rubber is less sensitive to heat and chemically stable.

The vulcanization accelerator refers to an accelerator that promotes the vulcanization rate or accelerates the retardation in the initial vulcanization step.

Examples of the vulcanization accelerator include sulfenamide, thiazole, thiuram, thiourea, guanidine, dithiocarbamate, aldehyde-amine, aldehyde-ammonia, imidazoline, Or a combination thereof.

Examples of the sulfenamide type vulcanization accelerator include N-cyclohexyl-2-benzothiazyl sulfenamide (CBS), N-tert-butyl-2-benzothiazyl sulfenamide (TBBS), N, N-dicyclohexyl -2-benzothiazyl sulfenamide, N-oxydiethylene-2-benzothiazyl sulfenamide, N, N-diisopropyl-2-benzothiazole sulfenamide, and combinations thereof Based compound can be used.

Examples of the thiol-based vulcanization accelerator include 2-mercaptobenzothiazole (MBT), dibenzothiazyl disulfide (MBTS), sodium salt of 2-mercaptobenzothiazole, zinc salt of 2-mercaptobenzothiazole , A copper salt of 2-mercaptobenzothiazole, a cyclohexylamine salt of 2-mercaptobenzothiazole, 2- (2,4-dinitrophenyl) mercaptobenzothiazole, 2- Ethyl 4-morpholinothio) benzothiazole, and combinations thereof. The thiazole-based compound may be used alone or in combination of two or more thereof.

Examples of the thiuram-based vulcanization accelerator include tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide, tetramethylthiuram monosulfide, dipentamethylthiuram disulfide, dipentamethylthiuram monosulfide, dipentamethylene Any one of thiuram-based compounds selected from the group consisting of thiuram tetrasulfide, dipentamethylenethiuram hexasulfide, tetrabutylthiuram disulfide, pentamethylenethiuram tetrasulfide, and combinations thereof can be used.

Examples of the thiourea vulcanization accelerator include thiourea compounds selected from the group consisting of thiacarbamide, diethyl thiourea, dibutyl thiourea, trimethyl thiourea, diorthotolyl thiourea, and combinations thereof. Compounds may be used.

Examples of the guanidine-based vulcanization accelerator include guanidine-based compounds selected from the group consisting of diphenyl guanidine, diorthotolyl guanidine, triphenyl guanidine, orthotolyl biguanide, diphenyl guanidine phthalate, and combinations thereof .

Examples of the dithiocarbamate-based vulcanization accelerator include zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, Zinc dibutyldithiocarbamate, zinc diamidithiocarbamate, zinc dipropyldithiocarbamate, complexation of zinc with piperidinedithiocarbamate and piperidine, zinc hexadecylisopropyldithiocarbamate, octadecyl Isopropyl dithiocarbamic acid zinc zinc dibenzyldithiocarbamate, sodium diethyldithiocarbamate, penta methylenedithiocarbamate, sodium selenium dimethyldithiocarbamate, diethyldithiocarbamate, sodium diethyldithiocarbamate, Cadmium dithiocarbamate, and combinations thereof. The dithiocarbamic acid-based compound may be used alone or in combination of two or more thereof.

Examples of the aldehyde-amine type or aldehyde-ammonia type vulcanization accelerator include aldehyde selected from the group consisting of acetaldehyde-aniline reactant, butylaldehyde-aniline condensate, hexamethylenetetramine, acetaldehyde-ammonia reactant, -Amine-based or aldehyde-ammonia-based compounds may be used.

As the imidazoline-based vulcanization accelerator, for example, an imidazoline-based compound such as 2-mercaptoimidazoline can be used. Examples of the xanthate vulcanization accelerator include xanthates such as zinc dibutylxanthogenate Compounds may be used.

The vulcanization accelerator may be added in an amount of 1.0 to 2.5 parts by weight based on 100 parts by weight of the raw material rubber in order to maximize productivity improvement and rubber property improvement by accelerating vulcanization speed.

The vulcanization accelerating assistant may be any one selected from the group consisting of an inorganic vulcanization accelerator aid, an organic vulcanization accelerator aid, and a combination thereof, which is used in combination with the vulcanization accelerator to complete the promoting effect thereof .

As the inorganic vulcanization accelerating aid, any one selected from the group consisting of zinc oxide (ZnO), zinc carbonate, magnesium oxide (MgO), lead oxide, potassium hydroxide and combinations thereof may be used have. As the organic vulcanization accelerating auxiliary, there may be selected from the group consisting of stearic acid, zinc stearate, palmitic acid, linoleic acid, oleic acid, lauric acid, dibutyl ammonium oleate, derivatives thereof, Can be used.

The vulcanization accelerator aid may be used in an amount of 2.5 to 5 parts by weight and 5 parts by weight based on 100 parts by weight of the raw rubber. If the content of the vulcanization accelerator auxiliary is less than the above range, the vulcanization rate may be slow and the productivity may be deteriorated. If the content exceeds the above range, the scorch phenomenon may occur and the physical properties may be lowered.

In addition to the above-mentioned composition, various additives such as antioxidants and processing aids used in conventional tire tread compositions can be optionally used in the present invention.

The present invention also provides a tire produced using the rubber composition for a tire tread.

The rubber composition for a tire tread can be produced through a conventional two-step continuous manufacturing process. That is, during the finishing step in which the first stage of thermomechanical treatment or kneading and the crosslinking system are mixed at a maximum temperature of 110 to 190 占 폚, preferably at a high temperature of 130 to 180 占 폚, typically less than 110 占 폚, And a second step of mechanical treatment at a low temperature of 40 to 100 DEG C in a suitable mixer, but the present invention is not limited thereto.

The rubber composition for a tire tread is not limited to a tread (a tread cap and a tread base) but may be included in various rubber components constituting the tire. Said rubber components include sidewalls, sidewall inserts, apex, chafer, wire coat or inner liner.

A tire according to another embodiment of the present invention is manufactured using the rubber composition for the tire tread. The method of manufacturing a tire using the rubber composition for a tire tread may be any method conventionally used for manufacturing a tire, and a detailed description thereof will be omitted herein.

The tire may be a light truck radial (LTR) tire, an ultra-high performance tire, a racing tire, an off-the-road tire, a car tire, an airplane tire, Tire or the like. Further, the tire may be a radial tire or a bias tire, and preferably a radial tire.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[ Manufacturing example  1: Preparation of oil extracted from microalgae]

Aurantiochytrium sp . ) Microalgae were cultured and centrifuged to remove the culture medium. The harvested microalgae were extracted with hexane solvent extraction method and the fatty acid composition in the oil was analyzed and shown in Table 1 below.

C16: 0 37% Palmitic acid C18: 0 One% Stearic acid C18: 1 One% Oleic acid C18: 2 2% Linoleic acid C20: 5 One% EPA (Eicosapentaenoic acid) C22: 5 13% Docosapentaenoic acid (DPA) C22: 6 42% Docosahexaenoic acid (DHA) Others 3% Total 100%

As shown in Table 1, the oil extracted from the microalgae contains eicosapentaene having 5 to 6 double bonds including 1% of oleic acid, 2% of linoleic acid, It was confirmed that EPA, Eicosapentaenoic acid (EPA), Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) account for about 56% of the total.

[ Manufacturing example  2: Preparation of rubber composition]

Rubber compositions for tire treads according to the following Examples and Comparative Examples were prepared using the compositions shown in Table 2 below. The production of the rubber composition was in accordance with the usual production method of the rubber composition.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 NR ¹⁾ 10 10 10 10 10 S-SBR ^{1 )} 60 60 60 60 60 BR ¹⁾ 30 30 30 30 30 Carbon black ^{2 )} 10 10 10 10 10 Silica ^{2 )} 90 90 90 90 90 Coupling agent 15 15 15 15 15 Synthetic oil ^{3 )} - - - - 20 Fine algae oil ^{4 )} 20 20 20 20 - Zinc oxide 2 2 3 3 2 Antioxidant 6 6 6 6 6 Sulfur vulcanizing agent 0.7 0.77 0.7 0.77 0.7 accelerant 2.3 2.3 2.3 2.3 2.3

(Unit: parts by weight)

1) 100 parts by weight of raw rubber

-NR (natural rubber): As natural rubber, the chemical name is polyisoprene

-S-SBR: Solution-polymerized styrene-butadiene rubber (SBR) having a styrene content of 35%, a vinyl content of butadiene of 25% and a Tg of -35 ° C, SRAE oil 37.5 PHR (content of S-SBR in Table 2 Is the content of S-SBR exclusive of oil content)

-BR: Butadiene rubber prepared by neodymium or nickel catalyst

2) Reinforcing filler

Carbon black: carbon black having a nitrogen adsorption value of 140 m < 2 > / g and a CTAB value of 130 m &

- Silica: Highly disperse silica having a nitrogen adsorption value of 175 m < 2 > / g and a CTAB value of 160 m &

3) Synthetic oil: PolyCyclic Aromatic Hydrocarbon (PAH) component having a total content of 3% by weight or less and a kinematic viscosity of 95 SUS (210 S SUS), 20% by weight of an aromatic component in a softener, 30% by weight of a naphthene component, A synthetic oil having a composition of 40% by weight

4) Microalgae oil: Microalgae obtained from the solvent extraction in Preparation Example 1, the genus Orantiochytrium ( Aurantiochytrium sp . ) As a lipid, fine algae natural oil consisting of 50% or more unsaturated fatty acids and other saturated fatty acids

[ Experimental Example  1: Measurement of physical properties of rubber composition]

The physical properties of the rubber specimens prepared in Examples and Comparative Examples were measured and the results are shown in Table 2 below.

The obtained specimens were measured for Mooney viscosity, hardness, 300% modulus and viscoelasticity according to the ASTM regulations, and the results are shown in Table 2.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Mooney viscosity 95 104 106 121 106 Hardness (Shore A) 72 70 70 73 73 300% modulus 97.2 116 104 126 136 Breaking energy (kgf / ㎠) 208 207 203 200 201 Tg (占 폚) -25.3 -24.8 -25.1 -24.8 -21.3 -40 占 폚 G '(dyne / cm2) 40.7 35.2 35.2 39.2 46.7 0 deg. 0.232 0.239 0.241 0.241 0.243 60 deg. 0.134 0.121 0.127 0.137 0.128

1) Mooney Viscosity (ML1 + 4 (100 ° C)): Using a Mooney MV2000 (Alpha Technology) machine, using a large rotor, preheating for 1 minute, rotor operating time of 4 minutes, . The Mooney viscosity is a value indicating the viscosity of the unvulcanized rubber. The higher the Mooney viscosity value, the larger the viscosity of the rubber. Thus, the workability can be deteriorated. The lower the Mooney viscosity value, the better the workability.

2) Hardness: measured by DIN 53505 using a Shore A hardness meter. The higher the hardness value, the better the adjustment stability.

3) 300% modulus: 300% modulus is the tensile strength at 300% elongation, measured according to ISO 37 standard.

4) Breaking energy: It refers to the energy when the rubber breaks according to the ISO 37 standard, and the strain energy until the test piece is broken in the tensile tester is measured by numerical value. The higher the breaking energy, the better the wear performance.

5) Viscoelasticity: The viscoelasticity was measured by using an ARES measuring instrument at GHz, G?, And tan? In a range of -60 to 70 ° C under a frequency of 10 Hz at 0.5% strain. Tg and -40 ℃ G shows the braking characteristics on the ice and snow surface. The lower the value, the better. The 0 ° C tan δ indicates the braking performance on a dry road surface or wet road surface. The higher the value, the better the braking performance. The 60 ° C tan δ is a measure of the rotational resistance at 60 ° C. .

Example 1 is a softener containing micro algae oil instead of synthetic oil, but added at a general level without increasing the content of sulfur vulcanizing agent and zinc oxide (cariogenic oil preparation). It was confirmed that the mechanical properties and the low fuel consumption characteristics of Example 1 were somewhat lower than those of Comparative Example.

Example 2 improves the low fuel consumption characteristics by increasing the sulfur content and preventing compound drop due to a large amount of double bonds contained in the oil extracted from microalgae. Examples 3 and 4 show that zinc oxide is increased in Examples 1 and 2 As a result, it was confirmed that the mechanical properties and braking performance were improved.

[ Experimental Example  2: Measurement of physical properties of tire]

The 215 / 60R16 standard tire comprising the rubber of the comparative example and the example as a semi-finished product was manufactured, and the tire was tested for its low-fuel-consumption performance, braking distance, performance on ice and snow surface, Table 4 shows the relative ratios to wear results.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Rotation resistance 97 105 101 95 100 Wet road braking performance 99 100 100 100 100 Ice and snow road surface braking performance 112 110 105 107 100 Abrasion resistance 110 111 107 105 100

In Examples 2, 3 and 4, the oil extracted from the microalgae was used. In Example 2, the sulfur-based vulcanizing agent was increased by 10 wt%, in Example 3, zinc oxide was increased by 10 wt% By weight, and by 10% by weight of zinc oxide.

The relative ratio value has a large influence on the improvement and reduction when the variation width is 5 or more, and when the increase ratio is less than 95, the performance is insufficient, and when it is 105 or more, the performance improvement is remarkable.

As can be seen from Table 4, when Examples 1 to 4 were compared with Comparative Example 1, it was confirmed that Tg indicating the braking characteristics on the ice and snow surface and the G "of -40 ° C were lowered as a result of using the oil extracted from the microalgae have. In particular, as compared with Example 1, excellent values were observed in terms of braking performance on road surface and wear resistance.

As compared with Comparative Example 1, the Tg of the rubber composition was reduced by applying the micro-algae natural oil in Examples 2, 3 and 4, and the braking performance on the wet road surface was maintained and the ice- . As a result of the comprehensive evaluation, the wet road surface braking performance of Example 2 was the same as that of Comparative Example 1, and the rotational resistance, ice-on-road braking performance, and abrasion resistance performance were all improved.

As described above, in the case of applying the natural oil extracted from the microalgae instead of the conventional synthetic oil and increasing the sulfur vulcanizing agent and the vulcanization accelerating agent, it is possible to improve the compatibility of the rubber to improve the rolling resistance and the braking performance on the wet road surface And showed excellent results in rotational resistance and braking performance and wear resistance on the ice surface.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

Claims (9)

100 parts by weight of the raw rubber,
70 to 120 parts by weight of a reinforcing filler, and
10 to 50 parts by weight of oil extracted from microalgae
And a rubber composition for a tire tread. The method according to claim 1,
Wherein the raw material rubber comprises 5 to 10% by weight of natural rubber, 40 to 70% by weight of solution-polymerized styrene-butadiene rubber and 20 to 50% by weight of butadiene rubber with respect to the total weight of the raw material rubber. 3. The method of claim 2,
The solution-polymerized styrene-butadiene rubber has a styrene content of 20 to 50% by weight, a vinyl content of 10 to 40% by weight, and SRAE (Special residual aromatic extract) oil is mixed with 100 parts by weight of the solution- To 40 parts by weight, and has a glass transition temperature of -50 to -20 占 폚,
Wherein the butadiene rubber has a cis-1,4-butadiene content of 95 to 100% by weight and a glass transition temperature of -120 to -100 ° C. The method according to claim 1,
Wherein the reinforcing filler comprises 65 to 100 parts by weight of silica and 5 to 20 parts by weight of carbon black with respect to 100 parts by weight of the raw material rubber,
The silica is a highly disperse silica having a nitrogen adsorption specific surface area of 160 to 180 m 2 / g, a CTAB value of 150 to 170 m 2 / g, and a DBP oil absorption of 180 to 200 cc /
The carbon black has a nitrogen adsorption specific surface area of 30 to 300 m 2 / g and a DBP oil absorption of 60 to 180 cc / 100 g
Rubber composition for tire tread. The method according to claim 1,
The oils extracted from the microalgae may be selected from the group consisting of Aurantiochytrium , Schizochytrium , Thraustochytrium , Japonochytrium , UIkenia , Wherein the rubber composition is derived from any microalgae selected from the group consisting of Crypthecodinium , Haliphthoros , Isochrysis , and mixtures thereof. The method according to claim 1,
Wherein the oil extracted from the microalgae contains 35 to 40% by weight of palmitic acid, 0.5 to 1.5% by weight of stearic acid, and oleic acid based on the total weight of the oil extracted from the microalgae. 0.5 to 1.5% by weight of linoleic acid, 1.5 to 2.5% by weight of linoleic acid, 0.5 to 1.5% by weight of eicosapentaenoic acid (EPA), 10 to 15% by weight of docosapentaenoic acid (DPA) By weight, and 40 to 45% by weight of docosahexaenoic acid (DHA). The method according to claim 1,
Wherein the oil extracted from the microalgae is extracted using any one solvent selected from the group consisting of hexane, methanol, ethanol, petroleum ether, chloroform, and mixtures thereof. delete A tire produced by using the rubber composition for a tire tread according to any one of claims 1 to 7.