KR101132791B1 - 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 and a tire produced therefrom, which comprises a solution-polymerized styrene-butadiene rubber having a styrene content of 15 to 25% by weight and a butadiene-containing vinyl content of 60 to 65% 100 parts by weight of a raw rubber comprising 30 to 50 parts by weight of a styrene-butadiene rubber (SBR) and 10 to 30 parts by weight of a butadiene rubber (BR), and 60 to 90 parts by weight of silica, , And the molecules are coupled to each other by tin (Sn).

The rubber composition for a tire tread has excellent braking performance that can be reduced due to maximization of a low fuel consumption performance while maximizing a low fuel consumption performance by reducing hysteresis. Therefore, the rubber composition for a tire tread is excellent in workability in an uncrossing state, braking performance in a vulcanizing state, All of the characteristics can be improved.

SBR, butadiene rubber, BR, coupling, capping, tin, silicon, hydrophilic group, denaturation, hysteresis, low fuel consumption performance, braking performance, processability, wear performance, rotation resistance

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]

The present invention relates to a rubber composition for a tire tread and a tire produced using the same. More particularly, the present invention relates to a rubber composition for a tire tread which has excellent processability in an unvulcanized state and improves both braking performance, wear performance and fuel- And a tire manufactured using the same.

In recent years, due to the high performance of passenger cars, consumers are demanding high performance of tires. In particular, the demand for tires having abrasion resistance, handling performance, ride performance, wet braking performance and low fuel consumption, Applications are actively being reviewed. A lot of research has been made especially in the field of materials in order to develop a tire having both the abrasion resistance, the handling performance, the ride performance, the wet braking performance and the low fuel consumption.

In general, the amount of reinforcing filler is reduced to reduce the hysteresis loss by reducing the interaction between the reinforcing agent and the reinforcing agent to reduce the rotational resistance associated with the fuel economy of the tire.

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 reinforcement filler is reduced.

As described above, when the abrasion performance and the fuel consumption performance of the tire are improved in the material development technology of the present tires, the braking performance is rather lowered, and when the braking performance of the tire is improved, Lt; / RTI > In this way, each performance of the tire shows a phenomenon that when one performance is improved, the other performance is lowered. Therefore, a technology capable of improving one performance while minimizing another performance degradation or improving both performance at the same time Development is required.

 It is an object of the present invention to provide a rubber composition for a tire tread which is excellent in workability in an unvulcanized state and which improves both braking performance, wear performance and low fuel consumption performance.

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

In order to achieve the above object, a rubber composition for a tire tread according to an embodiment of the present invention comprises a solution-polymerized styrene-butadiene rubber having a styrene content of 15 to 25% by weight and a butadiene-containing vinyl content of 60 to 65% , 30 to 50 parts by weight of a styrene-butadiene rubber (S-SBR) and 10 to 30 parts by weight of a butadiene rubber (BR), and 60 to 90 parts by weight of silica, Is modified with the hydrophilic group, and the molecules are coupled to each other by tin (Sn).

The hydrophilic group may be any one selected from the group consisting of a hydroxyl group, an alkoxy group having 3 to 5 carbon atoms, an amine group, a carboxyl group, a silanol group, a sulfonyl group, and combinations thereof.

The solution-polymerized styrene-butadiene rubber may have a molecular weight distribution (MWD) of 1.3 to 1.5.

The raw material rubber preferably contains 30 to 50 parts by weight of a solution-polymerized styrene-butadiene rubber having a styrene content of 30 to 50% by weight, a vinyl content of butadiene of 20 to 30% .

The solution-polymerized styrene-butadiene rubber may have a molecular weight distribution (MWD) of 1.3 to 1.5.

The silica may have a nitrogen adsorption specific surface area of 155 to 185 m 2 / g and a cetyltrimethyl ammonium bromide (CTAB) adsorption specific surface area of 150 to 170 m 2 / g.

According to another embodiment of the present invention, there is provided a tire manufactured using the rubber composition for a tire tread.

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

The rubber composition for a tire tread includes a first solution-polymerized styrene-butadiene rubber (S-SBR) having a styrene content of 15 to 25% by weight as a starting rubber and a vinyl content of 60 to 65% by weight of butadiene.

In general, the solution-polymerized styrene-butadiene rubber can be produced by a continuous process and a batch process. The first solution polymerized styrene-butadiene rubber may be one prepared by a batch method in particular. The solution-polymerized styrene-butadiene rubber prepared by the continuous process has a somewhat better processability than the solution-polymerized styrene-butadiene rubber produced by the batch process. However, since a large amount of low molecular weight material causes a large amount of hysteresis loss, It is disadvantageous.

On the other hand, the first solution-polymerized styrene-butadiene rubber produced by the batch method has a molecular weight distribution (MWD) of 1.3 to 1.5, which shows a narrow molecular weight distribution as compared with the styrene-butadiene rubber produced by the continuous method, Performance and low fuel consumption performance are advantageous.

The first solution-polymerized styrene-butadiene rubber has a styrene content of 15 to 25% by weight and a vinyl content of 60 to 65% by weight of butadiene.

The first solution-polymerized styrene-butadiene rubber improves the physical properties of the rubber by modifying the terminal of the molecule to a hydrophilic group to increase the dispersibility of silica added as a reinforcing filler. The hydrophilic group for modifying the terminal of the molecule of the first solution-polymerized styrene-butadiene rubber is selected from the group consisting of a hydroxyl group, an alkoxy group having 3 to 5 carbon atoms, an amine group, a carboxyl group, a silanol group, a sulfonyl group, It can be either.

The first solution-polymerized styrene-butadiene rubber may be any method known in the art to modify the end of a molecule to a hydrophilic group, and a detailed description thereof will be omitted.

In addition, the first solution-polymerized styrene-butadiene rubber maximizes the fuel-efficiency performance by reducing the number of molecular ends where hysteresis occurs due to coupling or capping of molecules with tin (Sn).

The first solution-polymerized styrene-butadiene rubber is preferably used in an amount of 30 to 50 parts by weight for optimal rotational resistance, and when the content of the first solution polymerized styrene-butadiene rubber exceeds 50 parts by weight, And if it is less than 30 parts by weight, the rotational resistance characteristic and the braking performance may be lowered.

On the other hand, the raw rubber has a styrene content of 30 to 50% by weight, a vinyl content of butadiene of 20 to 30% by weight, and a second solution-polymerized styrene-butadiene rubber in which molecules are coupled with silicon (Si) .

If the rubber composition for a tire tread further comprises the second solution polymerized styrene-butadiene rubber, the braking performance which can be reduced due to the maximization of the low fuel consumption performance is compensated.

The content of the second solution polymerized styrene-butadiene rubber may be 30 to 50 parts by weight, and when the content of the second solution polymerized styrene-butadiene rubber is more than 50 parts by weight, The braking performance can be reduced.

The second solution-polymerized styrene-butadiene rubber may contain 25 to 50 parts by weight, preferably 35 to 40 parts by weight, of Treated Distillate Aromatic Extract (TDAE) oil per 100 parts by weight of the original rubbery elastomer. When the second solution polymerized styrene-butadiene rubber contains 25 to 50 parts by weight of TDAE oil per 100 parts by weight of the original rubbery elastomer, flexibility of the second solution polymerized styrene-butadiene rubber degraded by the influence of styrene can be expected.

The method of coupling or capping the solution-polymerized styrene-butadiene rubber with tin or silicon may be performed by a method known in the art, and is not limited to the specific method in the present invention.

For example, styrene-butadiene rubber coupled with tin or silicon can be prepared by copolymerizing styrene and 1,3-butadiene in an inert solution using an alkyl lithium catalyst. In addition, an auxiliary catalyst or a catalyst modifier may be used together with the alkyl lithium catalyst. After the styrene-butadiene rubber is produced using the catalyst, a tin compound or a silicon compound is added to terminate the reaction.

As the tin compound, tin tetrachloride, tin trialkyl chloride, tin dialkyldichloride or tin alkyl trichloride can be preferably used. As the silicon compound, silicon tetrachloride, trialkylsilicon chloride, dialkyldichlorosilane or alkyl trichloride Silicon can be preferably used.

The raw material rubber may further include a butadiene rubber. The butadiene rubber may be any of those conventionally used in rubber compositions for tire treads, and is not particularly limited in the present invention.

When the butadiene rubber is used in an amount of more than 30 parts by weight, the proportion of butadiene rubber having a relatively low rubber strength is increased, so that the braking performance of the tire may be deteriorated. When the amount of the butadiene rubber is less than 10 parts by weight , Wear performance of the tire may be deteriorated.

The tire tread rubber composition comprises silica as a reinforcing filler. In order to obtain a tread rubber composition suitable for the purpose of the present invention, the silica is preferably a silica having a nitrogen adsorption specific surface area of 155 to 185 m 2 / g and a cetyltrimethyl ammonium bromide (CTAB) adsorption specific surface area of 150 to 170 m 2 / g desirable.

The silica may be used in an amount of 60 to 90 parts by weight based on 100 parts by weight of the starting rubber. When the content of the silica exceeds 90 parts by weight, the rotational resistance may be reduced. When the amount of the silica is less than 60 parts by weight, .

The silica may be any of those prepared by a wet method or a dry method. Ultrasil VN2 (manufactured by Degussa) and Ultrasil VN3 (manufactured by Degussa) may be used as a commercially available product, but the present invention is not limited thereto.

The rubber composition for a tire tread may further include a coupling agent for improving dispersibility of the silica.

Examples of the coupling agent include sulfidic coupling agents, mercapto coupling agents, vinyl coupling agents, amino coupling agents, glycidoxine coupling agents, nitro coupling agents, chloro coupling agents, methacryl coupling agents and combinations thereof , And a sulfide-based coupling agent can be preferably used.

The sulfide-based coupling agent may be at least one selected from the group consisting of bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, bis (4-trimethoxysilylbutyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis Bis (3-trimethoxysilylethyl) trisulfide, bis (4-triethoxysilylethyl) trisulfide, bis (4-trimethoxysilylbutyl) trisulfide, bis (3-triethoxysilylbutyl) disulfide, bis (4-triethoxysilylbutyl) disulfide, bis 3-trimethoxysilylpropyl) disulfide, bis (2-trimethoxy Silylethyl) disulfide, bis (4-trimethoxysilylbutyl) disulfide, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, 3-triethoxysilylpropyl-N, Carbamoyltetrasulfide, 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyltetrasulfide, 2-trimethoxysilylethyl-N, N-dimethylthiocarbamoyltetrasulfide, 3-trimethoxysilylpropyl Benzothiazolyl tetrasulfide, 3-triethoxysilylpropyl benzothiazole tetrasulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, and combinations thereof. Lt; / RTI > group.

The mercapto-based coupling agent may be at least one selected from the group consisting of 3-mercaptopropyltrimethoxysilane, 3-mercaptotopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, And the like. The vinyl-based coupling agent may be any one selected from the group consisting of ethoxysilane, vinyltrimethoxysilane, and combinations thereof. Wherein the amino-based coupling agent is selected from the group consisting of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropyltriethoxysilane, 3- Methoxysilane, and a combination thereof.

The glycidoxine clock coupling agent may be selected from the group consisting of? -Glycidoxypropyltriethoxysilane,? -Glycidoxypropyltrimethoxysilane,? -Glycidoxypropylmethyldiethoxysilane,? -Glycidoxypropylmethyldimethoxysilane And a combination thereof. The nitro-based coupling agent may be any one selected from the group consisting of 3-nitropropyltrimethoxysilane, 3-nitropropyltriethoxysilane, and combinations thereof. The chloro-based coupling agent is selected from the group consisting of 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 2-chloroethyltrimethoxysilane, 2-chloroethyltriethoxysilane, and combinations thereof Lt; / RTI >

The methacrylic silane compound may be any one selected from the group consisting of? -Methacryloxypropyltrimethoxysilane,? -Methacryloxypropylmethyldimethoxysilane,? -Methacryloxypropyldimethylmethoxysilane, and combinations thereof Lt; / RTI >

The coupling agent may be contained in an amount of 4.8 to 7.2 parts by weight based on 100 parts by weight of the raw rubber. If the content of the coupling agent is less than 4.8 parts by weight, the reaction with silica may be insufficient to lower the workability of the rubber or deteriorate the fuel efficiency. When the amount of the coupling agent is more than 7.2 parts by weight, It may be excellent, but the braking performance may be very low.

The rubber composition for a tire tread may further include various additives such as additional vulcanizing agents, vulcanization accelerators, vulcanization accelerators, anti-aging agents, softening agents and the like. 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.

As the vulcanizing agent, metal oxides such as sulfur vulcanizing agents, organic peroxides, resin vulcanizing agents, and magnesium oxide can be 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.

The organic peroxide is selected from the group consisting of benzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, t-butyl cumyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, 2,5- butylperoxy) hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5- Bis (t-butylperoxypropyl) benzene, di-t-butylperoxy-diisopropylbenzene, t-butylperoxybenzene, 2,4-dichlorobenzoylperoxide, 1,1- , 3,5-trimethylsiloxane, n-butyl-4,4-di-t-butylperoxyvalerate, and combinations thereof.

It is preferable that the vulcanizing agent is contained in an amount of 0.5 to 4.0 parts by weight based on 100 parts by weight of the raw material rubber in view of providing a vulcanization effect that 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-based or aldehyde-ammonia-based vulcanization accelerator include aldehyde-aniline reactants, butylaldehyde-aniline condensates, hexamethylenetetramine, acetaldehyde-ammonia reactants, and combinations thereof. Dehydro-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 included in an amount of 0.5 to 4.0 parts by weight based on 100 parts by weight of the raw material rubber in order to maximize productivity improvement and rubber property enhancement through vulcanization speed promotion.

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.

In particular, the zinc oxide and the stearic acid may be used together as the vulcanization accelerating assistant. In this case, the zinc oxide is dissolved in the stearic acid to form an effective complex with the vulcanization accelerator, Thereby facilitating the crosslinking reaction of the rubber.

When the zinc oxide and the stearic acid are used together, they may be used in an amount of 1 to 5 parts by weight and 0.5 to 3 parts by weight, respectively, based on 100 parts by weight of the starting rubber to serve as a proper vulcanization accelerator.

The softening agent is added to the rubber composition in order to impart plasticity to the rubber to facilitate processing or to decrease the hardness of the vulcanized rubber, and means an oil or other material used in rubber compounding or rubber production. The softener may be selected from the group consisting of petroleum oils, vegetable oils, and combinations thereof, but the present invention is not limited thereto.

The petroleum-based oil may be selected from the group consisting of paraffinic oil, naphthenic oil, aromatic oil, and combinations thereof.

Examples of the paraffin oil include P-1, P-2, P-3, P-4, P-5 and P-6 of Mychang Oil Co., N-1, N-2 and N-3 of Kokai Co., Ltd., and representative examples of the aromatic oils include A-2 and A-3 of Mingchang Oil Co.,

However, recently, when the content of the polycyclic aromatic hydrocarbons (hereinafter, referred to as "PAHs ") contained in the aromatic oil is 3 wt% or more together with the increase in environmental consciousness, , Treated distillate aromatic extract (TDAE) oil, mild extraction solvate (MES) oil, residual aromatic extract (RAE) oil or heavy naphthenic oil.

Particularly, the oil used as the softener preferably has a total content of PAHs components of 3% by weight or less, a kinematic viscosity of 95 ° C or more (210 ° F. SUS), an aromatic component in the softener of 15 to 25% A TDAE oil having 27 to 37% by weight of a component and 38 to 58% by weight of a paraffin component can be preferably used.

The TDAE oil is advantageous for environmental factors such as the low temperature characteristics of the tire tread including the TDAE oil and the possibility of the cancer induction of PAHs while improving the fuel consumption performance.

Examples of the vegetable oils include vegetable oils such as castor oil, cottonseed oil, linseed oil, canola oil, soybean oil, palm oil, palm oil, peanut oil, pine oil, pine tar, tall oil, cone oil, rice bran oil, safflower oil, sesame oil, , Jojoba oil, macadamia nut oil, four flower oil, tung oil, and combinations thereof.

It is preferable that the softening agent is used in an amount of 0 to 150 parts by weight based on 100 parts by weight of the raw material rubber in order to improve workability of the raw material rubber.

It is preferable that the softening agent is used in an amount of 20 to 40 parts by weight based on 100 parts by weight of the raw material rubber, because it improves the workability of the raw rubber. The content of the softening agent is the sum of the content of the TDAE oil used in the raw rubber and the content of the processed oil.

The antioxidant is an additive used to stop the chain reaction in which the tire is autoxidized by oxygen. As the anti-aging agent, any one selected from the group consisting of an amine type, a phenol type, an imidazole type, a carbamic acid metal salt and a combination thereof can be appropriately selected and used.

Examples of the antioxidant include N- (1,3-dimethylbutyl) -N-phenyl-p-phenylenediamine (6PPD), N- N-isopropyl-p-phenylenediamine (3PPD) and poly (2,2,4-trimethyl-1,2-dihydroquinoline (Poly , 4-trimethyl-1,2-dihydroquinoline, RD), and combinations thereof.

Considering the conditions that the solubility of the antioxidant in addition to the anti-aging action is high, the solubility in the rubber is small, the volatility is small, the solubility should be inactive to the rubber, and the vulcanization should not be inhibited, By weight.

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 a first step (referred to as a "non-production" step) of thermomechanical treatment or kneading at a maximum temperature of 110-190 ° C, preferably 130-180 ° C, and a crosslinking system are mixed, Can be prepared in a suitable mixer using a second stage (referred to as "non-production" stage) of mechanically treating at a low temperature, typically below 110 ° C, for example 40-100 ° C, no.

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 tires may be automobile tires, racing tires, airplane tires, agricultural tires, off-the-road tires, truck tires or bus tires. Further, the tire may be a radial tire or a bias tire, and preferably a radial tire.

The rubber composition for a tire tread of the present invention is excellent in braking performance that can be reduced due to maximization of low fuel consumption performance while minimizing hysteresis to maximize low fuel consumption performance, thereby improving workability in uncured state, braking performance in vulcanized state, Both the rotational resistance characteristics can be improved.

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.

[Production Example: Production of Rubber Composition for Tire Tread]

(Examples and Comparative Examples)

Rubber compositions for tire treads according to Examples 1 to 4 and Comparative Examples 1 and 2 were prepared using the compositions shown in Table 1 below. The production of the rubber composition for a tire tread was in accordance with a conventional method for producing a tire tread rubber.

[Table 1] (Unit: parts by weight)

ingredient Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 E-SBR ⁽¹⁾ 80 - - - - - S-SBR ⁽²⁾ - 80 - 30 40 50 S-SBR ⁽³⁾ - 110
(80) 68.75
(50) 55
(40) 41.25
(30) BR ⁽⁴⁾ 20 20 20 20 20 20 Silica ⁽⁵⁾ 80 80 80 80 80 80 Coupling agent (Si69) 6.4 6.4 6.4 6.4 6.4 6.4 Zinc oxide 3.0 3.0 3.0 3.0 3.0 3.0 Stearic acid 1.0 1.0 1.0 1.0 1.0 1.0 brimstone 1.75 1.75 1.75 1.75 1.75 1.75 Promoters ⁽⁶⁾ 1.0 1.0 1.0 1.0 1.0 1.0 Accelerator (DPG) 2 2 2 2 2 2

(1) E-SBR: SBR 1502

(2) S-SBR: prepared by a batch method in which the content of styrene is 15 to 25% by weight and the content of vinyl butadiene is 60 to 65% by weight, the molecular weight distribution (MWD) is 1.3 to 1.5, Solution-polymerized styrene-butadiene rubber (SBR) modified with a hydrophilic group (hydroxyl group, -OH) and Sn-

(3) S-SBR: prepared by a batch method in which the styrene content is 30 to 50 wt% and the butadiene-containing vinyl content is 20 to 30 wt%, the molecular weight distribution (MWD) is 1.3 to 1.5, Styrene-butadiene rubber (SBR) containing 37.5 parts by weight of TDAE oil per 100 parts by weight of rubber solid content,

(4) BR: Butadiene rubber

(5) Silica: A precipitated silica having a nitrogen adsorption specific surface area of 170 m < 2 > / g and a CTAB adsorption specific surface area of 160 m &

(6) Accelerator: N-cyclohexyl-2-benzothiazyl sulfenamide (CBS)

[Experimental Example: Measurement of Physical Properties of Rubber for Tire Tread Manufactured]

The properties of the tire tread rubber prepared in Examples 1 to 4 and Comparative Examples 1 and 2 were measured and the results are shown in Table 2 below.

[Table 2]

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 Mooney viscosity 67 65 64 66 65 65 Hardness (Shore A) 66 65 66 66 66 65 300% modulus
(Mpa) 12.6 11.5 12.1 11.5 12.0 11.7 Elongation (%) 385 375 388 382 379 377 Wear Index 100 101 109 108 110 110 0 deg. 0.304 0.280 0.340 0.323 0.311 0.298 60 deg. 0.116 0.085 0.122 0.105 0.091 0.090

- Mooney viscosity (ML1 + 4 (125 占 폚)) was measured according to ASTM standard D1646.

- Hardness was measured by DIN 53505

- 300% Modulus and elongation were measured according to ISO 37 standard.

- The viscoelasticity was measured by using an RDS measuring instrument at a temperature of 60 ° C to 80 ° C under 0.1Hz strain at a frequency of 10Hz.

In Table 2, the Mooney viscosity is a value indicating the viscosity of the unvulcanized rubber, and the lower the numerical value, the better the workability of the unvulcanized rubber. The wear rate is a Lambourn abrasion tester. The 0 ° C tan δ indicates the braking performance. The higher the value, the better the braking performance. The 60 ° C tan δ indicates the rotational resistance characteristic, and the lower the value, the better the performance. The hardness indicates the adjustment stability, and the higher the value, the better the adjustment stability.

Referring to Table 2, the rubber for tire tread prepared in Examples 1 to 4 has the braking performance, the wear performance, and the rotational resistance characteristics while maintaining the same adjustment stability as that of the rubber for tire tread prepared in Comparative Examples 1 and 2 It can be seen that both are improved.

However, in the case of Example 1, the braking performance is excellent, but the fuel-combustion performance is expected to be disadvantageous as compared with Examples 2 to 3. In Example 3, the braking performance is expected to be low. In the case of the second embodiment, proper braking performance and excellent fuel consumption performance are exhibited.

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 (7)

30 to 50 parts by weight of a first solution polymerized styrene-butadiene rubber (S-SBR) having a styrene content of 15 to 25% by weight and a vinyl content of 60 to 65% by weight of butadiene, a styrene content of 30 to 50% 30 to 50 parts by weight of a second solution polymerized styrene-butadiene rubber in which the vinyl content of the butadiene is 20 to 30% and the molecules are bonded by silicon (Si), and 10 to 30 parts by weight of butadiene rubber (BR) 100 parts by weight of the raw rubber included, and 60 to 90 parts by weight of silica, The first solution-polymerized styrene-butadiene rubber has a structure in which the terminal of the molecule is modified with a hydrophilic group, the molecules are mutually coupled by tin (Sn) Wherein the hydrophilic group is any one selected from the group consisting of a hydroxyl group, an alkoxy group having 3 to 5 carbon atoms, an amine group, a carboxyl group, a silanol group, a sulfonyl group, and combinations thereof. delete The method according to claim 1, Wherein the first solution polymerized styrene-butadiene rubber has a molecular weight distribution (MWD) of 1.3 to 1.5. delete The method according to claim 1, Wherein the second solution-polymerized styrene-butadiene rubber has a molecular weight distribution (MWD) of 1.3 to 1.5. The method according to claim 1, Wherein the silica has a nitrogen adsorption specific surface area of 155 to 185 m < 2 > / g and a specific surface area of CTAB adsorption of 150 to 170 m < 2 > / g. A tire produced by using the rubber composition for a tire tread according to any one of claims 1, 3, 5 and 6.