KR101293471B1 - 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 manufactured using the same, comprising 40 to 80 parts by weight of an emulsion-polymerized styrene-butadiene rubber (E-SBR), a Si-coupled solution-polymerized styrene-butadiene rubber (S- SBR) 100 parts by weight of raw rubber, including 10 to 40 parts by weight, and 10 to 30 parts by weight of nickel butadiene rubber having a sheath content of 96% by weight or more and a glass transition temperature of -105 to -110 ° C, and 30 to 50 weight of silica. Parts, and 30 to 50 parts by weight of carbon black.
The rubber tread rubber composition is environmentally friendly and can improve workability in the unvulcanized state, improve wet braking performance in the vulcanized state and at the same time reduce the rolling resistance.

Description

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

The present invention relates to a rubber composition for a tire tread and a tire manufactured using the same, and more particularly, to a rubber composition for a tire tread and a tire manufactured using the same, which can simultaneously improve environment-friendly processability and low fuel consumption. .

Recently, the tire industry is intensively researching tires that are eco-friendly and can reduce rolling resistance due to environmental regulations on the use of eco-friendly materials in each country, increasing demand for low fuel consumption caused by unstable oil supply and demand, and rising oil prices.

In general, techniques for reducing rolling resistance reduce the amount of reinforcing fillers to reduce the interaction between the reinforcing agents, but this technique is a key characteristic of the tire tread, which is an important characteristic of the tire tread, as the amount of the reinforcing fillers is reduced. Reduced steering stability and disadvantages, as well as lower wear performance, limit the improvement of rolling resistance through reduced tire tread weight.

In addition, many efforts have been made to improve the interaction of carbon black with rubber, which is used as a reinforcing filler, as another method for reducing rolling resistance. However, carbon black has its limitations in nature, and silica black is used as a solution. Silica is highly polar and not easily miscible with non-polar rubbers, so some of them can be blended with carbon black or silica fuel surface modified or end-modified and coupled synthetic rubbers for low fuel efficiency, abrasion resistance, handling and The development of tires that combine ride performance and wet braking is being actively investigated.

On the other hand, when the PAH content in aromatic oils is higher than 3% by weight with increasing environmental awareness, it is known that cancer is likely to occur, and the European Rubber Association (BRIC) has accepted the results and prepared measures. All tire manufacturers consider this to be an urgent problem by establishing a regulation to use and by enacting a ban on sales when the PAH content is more than 3% by weight.

As mentioned above, the market demands the development of new materials and the use of eco-friendly materials for the performance improvement of tires at the same time, and technology for the discovery of eco-friendly materials and the improvement of tire performance using the same has been a hot topic in the industry recently.

It is an object of the present invention to provide a tire tread rubber composition that is not only environmentally friendly but can also improve low fuel economy 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, the rubber composition for a tire tread according to an embodiment of the present invention is 40 to 80 parts by weight of emulsion polymerization styrene-butadiene rubber (E-SBR), Si-coupled solution polymerization styrene-butadiene rubber ( S-SBR) 100 parts by weight of raw rubber, 10 to 40 parts by weight, and 10 to 30 parts by weight of a nickel butadiene rubber having a sheath content of 96% by weight or more and a glass transition temperature of -105 to -110 ° C, and silica of 30 to 40 parts by weight. 50 parts by weight, and 30 to 50 parts by weight of carbon black.

The Si-coupled solution polymerized styrene-butadiene rubber has a styrene content of 30 to 50% by weight, a vinyl content of butadiene is 20 to 40% by weight, a glass transition temperature of -25 to -35 ° C, and The viscosity can be 75 to 85.

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

The carbon black may have an iodine adsorption specific surface area of 85 to 95 mg / g, a DBP oil absorption of 117 to 127 cc / 100 g, and a tint value of 107 to 115.

The emulsion-polymerized styrene-butadiene rubber has a polycyclic aromatic hydrocarbon (PAH) component of 3 wt% or less, a kinematic viscosity of 95 (210 ° F. SUS) or more, an aromatic component of 15 to 25 wt%, and a naphthenic component of 27 to 37 Softeners with a weight percent and 38-58 weight percent of the paraffinic component.

A tire according to another embodiment of the present invention is manufactured using the rubber composition for a tire tread.

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

The tire tread rubber composition may contain 40 to 80 parts by weight of emulsion-polymerized styrene-butadiene rubber (E-SBR), 10 to 40 parts by weight of Si-coupled solution-polymerized styrene-butadiene rubber (S-SBR), and a sheath content. 100 parts by weight of raw rubber including at least 96% by weight and 10 to 30 parts by weight of nickel butadiene rubber having a glass transition temperature of -105 to -110 ° C, 30 to 50 parts by weight of silica, and 30 to 50 parts by weight of carbon black. .

The rubber tread rubber composition is an Si-coupled solution-polymerized styrene-butadiene rubber (S-) capable of improving wet braking properties and low fuel consumption to an emulsion-polymerized styrene-butadiene rubber (E-SBR) containing an environmentally friendly softener. SBR) is blended and carbon black, which is highly dispersible and favorable for processability and low fuel consumption, is not only environmentally friendly, but also meets low rolling resistance requirements.

The emulsion-polymerized styrene-butadiene rubber (E-SBR) may have a styrene content of 10 to 50% by weight, butadiene content of 15 to 18%, and include 40 to 80 parts by weight of the total raw rubber. Can be. When the content of the emulsion-polymerized styrene-butadiene rubber exceeds 80 parts by weight, it may cause a decrease in braking performance in a wet road surface state, and when it is less than 40 parts by weight, it may show a decrease in workability and wear performance.

The emulsion polymerized styrene-butadiene rubber may be an aromatic oil contained in the emulsion polymerized styrene-butadiene rubber with a treated distillate aromatic extract (TDAE) oil having a low polycyclic aromatic hydrocarbon (PAH) content.

PAHs known as carcinogenic substances include benzo (a) pyrene, benzo (e) pyrene (C ₂₀ H ₁₂ ), benzo (b) fluoranthene, C ₂₀ H ₁₂ ), Benzo (j) fluoranthene (C ₂₀ H ₁₂ ), benzo (b) fluoranthene (Benzo (a) Anthtacene, C ₂₀ H ₁₂ ), benzo (k) fluoranthene ( Eight substances of Benzo (k) Fluoranthene, C ₂₀ H ₁₂ ), Chrysene, C ₁₈ H ₁₂ ) and Dibenzo (a, h) Anthracene, C ₂₀ H ₁₂ ) it means.

The TDAE oil has a total content of the PAH component of 3% by weight or less, a kinematic viscosity of 15 to 25 (100 ° C, cSt), an aromatic component of 15 to 25% by weight, a naphthenic component of 27 to 37% by weight, and paraffin. System components may be 38 to 58% by weight.

The Si-coupled solution-polymerized styrene-butadiene rubber (S-SBR) improves dispersibility with silica and improves physical properties of the rubber, and connects each molecule through Si-coupling to generate hysteresis. By reducing the number of fuel cells, low fuel consumption can be maximized.

The Si-coupled solution polymerized styrene-butadiene rubber has a styrene content of 30 to 50% by weight, a vinyl content of butadiene is 20 to 40% by weight, a glass transition temperature of -25 to -35 ° C, and The viscosity is 75 to 85, it is used in 10 to 40 parts by weight of the raw material rubber. When the content of the Si-coupled solution-polymerized styrene-butadiene rubber exceeds 40 parts by weight, wear performance may decrease, and when the content of the Si-coupled solution polymerized styrene-butadiene rubber is less than 10 parts by weight And braking performance may be degraded.

The nickel butadiene rubber is a butadiene rubber prepared using a nickel catalyst, has a high degree of crosslinking, a cis content of 96% by weight or more, and a low glass transition temperature of -105 to -110 ° C. The nickel butadiene rubber has excellent processability in the mixing and extrusion process due to the wide molecular weight distribution properties, and by mixing it with a solution-polymerized styrene-butadiene rubber, it is possible to obtain a tread rubber composition having better wear characteristics and reduced hysteresis.

The nickel butadiene rubber may be included in 10 to 30 parts by weight of the total raw rubber, when the content of the nickel butadiene rubber exceeds 30 parts by weight, the braking performance may be reduced, when less than 15 parts by weight wear performance may be reduced have.

The tire tread rubber composition includes silica and carbon black as reinforcing fillers.

The silica has a nitrogen adsorption specific surface area of 155 to 185 m 2 / g, and the use of silica having a CTAB (cetyltrimethyl ammonium bromide) adsorption specific surface area of 150 to 170 m 2 / g is preferred for improving low fuel consumption and wear performance.

The silica may be used in an amount of 30 to 50 parts by weight based on 100 parts by weight of the raw material rubber, and when the content of the silica exceeds 50 parts by weight, low fuel consumption There may be a problem that the performance is reduced, if less than 30 parts by weight may have a problem that the wear performance is disadvantageous.

The carbon black may have an iodine adsorption specific surface area of 85 to 95 mg / g, a carbon black having a DBP (n-dibutyl phthalate) oil absorption of 117 to 127 cc / 100 g, and a tint of 107 to 115. When the iodine adsorption specific surface area of the carbon black exceeds 95 mg / g, the workability of the rubber composition for a tire may be detrimental, and if it is less than 85 mg / g, reinforcing performance by the carbon black filler may be detrimental. In addition, when the DBP oil absorption of the carbon black exceeds 127cc / 100g, the workability of the rubber composition may be lowered. If the DBP oil absorption amount is less than 117cc / 100g, the reinforcing performance of the carbon black as a filler may be detrimental.

The carbon black may be included in an amount of 30 to 50 parts by weight, and more preferably 35 to 45 parts by weight, based on 100 parts by weight of the raw material rubber. When the content of the carbon black is less than 30 parts by weight, the reinforcing performance by the carbon black as a filler may be reduced, and when the content of the carbon black exceeds 50 parts by weight, the processability of the rubber composition may be deteriorated.

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 the like.

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 N, N-dimethylthiocarbamoyltetrasulfide, 3-triethoxysilylpropyl-N, N-dimethylthiourea, 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 is preferably 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 is any one selected from the group consisting of γ-methacryloxypropyl trimethoxysilane, γ-methacryloxypropyl methyldimethoxysilane, γ-methacryloxypropyl dimethyl methoxysilane, and combinations thereof Can be.

The coupling agent may be included in an amount of 5 to 10 parts by weight based on 100 parts by weight of the raw material rubber. When the content of the coupling agent is less than 5 parts by weight, the workability of the rubber may be reduced or the rubber strength may be lowered. When the content of the coupling agent is more than 10 parts by weight, the effect of improving the workability of the rubber is small while the cost is increased and it is not economical. Strength may be lowered.

The rubber composition for a tire tread may further comprise various additives such as an additional vulcanizing agent, a vulcanization accelerator, a vulcanization accelerator, an anti-aging agent or a softening agent. The various additives can be used as long as it is commonly used in the field of the present invention, the content thereof is not particularly limited, depending on the compounding ratio used in the conventional tire tread rubber composition.

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

The sulfur-based vulcanizing agents include inorganic vulcanizing agents such as powdered sulfur (S), insoluble sulfur (S), precipitated sulfur (S) and colloidal sulfur, tetramethylthiuram disulfide (TMTD) and tetraethyl. Organic vulcanizing agents such as tetraethyltriuram disulfide (TETD) and dithiodimorpholine can be used. Specifically, as the sulfur vulcanizing agent, a vulcanizing agent which produces elemental sulfur or sulfur, for example, amine disulfide, polymer sulfur, or the like can be used.

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

The vulcanizing agent is preferably included in an amount of 0.5 to 2.0 parts by weight based on 100 parts by weight of the raw material rubber, in that the raw material rubber is less sensitive to heat and chemically stable.

The vulcanization accelerator refers to an accelerator that promotes the rate of vulcanization or promotes delay in the initial vulcanization stage.

The vulcanization accelerators include sulfenamide, thiazole, thiuram, thiourea, guanidine, dithiocarbamic acid, aldehyde-amine, aldehyde-ammonia, imidazoline, xanthate and their Any one selected from the group consisting of a combination can be used.

Examples of the sulfenamide vulcanization accelerators include N-cyclohexyl-2-benzothiazylsulfenamide (CBS), N-tert-butyl-2-benzothiazylsulfenamide (TBBS), and N, N-dicyclohexyl. Any selected from the group consisting of -2-benzothiazylsulfenamide, N-oxydiethylene-2-benzothiazylsulfenamide, N, N-diisopropyl-2-benzothiazolesulfenamide and combinations thereof The sulfenamide type compound of can be used.

Examples of the thiazole vulcanization accelerators include 2-mercaptobenzothiazole (MBT), dibenzothiazyl disulfide (MBTS), sodium salt of 2-mercaptobenzothiazole and zinc salt of 2-mercaptobenzothiazole. , Copper salt of 2-mercaptobenzothiazole, cyclohexylamine salt of 2-mercaptobenzothiazole, 2- (2,4-dinitrophenyl) mercaptobenzothiazole, 2- (2,6-di Any thiazole compound selected from the group consisting of ethyl 4-morpholinothio) benzothiazole and combinations thereof can be used.

Examples of the thiuram-based vulcanization accelerators include tetramethyl thiuram disulfide (TMTD), tetraethyl thiuram disulfide, tetramethyl thiuram monosulfide, dipentamethylene thiuram disulfide, dipentamethylene thiuram monosulfide and dipentamethylene. Any thiuram-based compound selected from the group consisting of thiuram tetrasulfide, dipentamethylene thiuram hexasulfide, tetrabutyl thiuram disulfide, pentamethylene thiuram tetrasulfide, and combinations thereof can be used.

As the thiourea vulcanization accelerator, for example, thiocarbamide, diethylthiourea, dibutylthiourea, trimethylthiourea, diorthotolylthiourea, and any combination thereof is selected from the group of thiourea Compounds can be used.

As the guanidine-based vulcanization accelerator, for example, any one guanidine-based compound selected from the group consisting of diphenylguanidine, diorthotolylguanidine, triphenylguanidine, orthotolylbiguanide, diphenylguanidine phthalate, and combinations thereof can be used. Can be.

Examples of the dithiocarbamic acid-based vulcanization accelerators include ethylphenyldithiocarbamate zinc, butylphenyldithiocarbamate zinc, sodium dimethyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, Zinc dibutyldithiocarbamate, zinc diamyldithiocarbamate, zinc dipropyldithiocarbamate, zinc salt of pentamethylenedithiocarbamate and piperidine, hexadecylisopropyldithiocarbamate zinc, octadecyl Isopropyldithiocarbamate zinc dibenzyldithiocarbamate zinc, sodium diethyldithiocarbamate, pentamethylenedithiocarbamate piperidine, dimethyldithiocarbamate selenium, diethyldithiocarbamate tellurium, dia One dithiocarbamic acid compound selected from the group consisting of cadmium didicarbamate and combinations thereof can be used.

The aldehyde-amine-based or aldehyde-ammonia based vulcanization accelerator, for example, acetaldehyde-aniline reactant, butylaldehyde-aniline condensate, hexamethylenetetramine, acetaldehyde-ammonia reactant and combinations thereof -Amine based or aldehyde-ammonia based compounds can be used.

As said imidazoline type vulcanization accelerator, imidazoline type compounds, such as 2-mercaptoimidazoline, can be used, for example, As said xanthate type vulcanization accelerator, xanthate type, such as zinc dibutyl xanthogenate Compounds can 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 and rubber properties by promoting the vulcanization rate.

The vulcanization accelerator is a compounding agent used in combination with the vulcanization accelerator to complete its promoting effect. Any one selected from the group consisting of inorganic vulcanization accelerators, organic vulcanization accelerators and combinations thereof can be used. .

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. The organic vulcanization accelerator is selected from the group consisting of stearic acid, zinc stearate, palmitic acid, linoleic acid, oleic acid, lauric acid, dibutyl ammonium oleate, derivatives thereof, and combinations thereof. You can use either one.

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 raw rubber to serve as a proper vulcanization accelerator.

The softener is added to the rubber composition to impart plasticity to the rubber to facilitate processing or to lower the hardness of the vulcanized rubber, and refers to oils and other materials used in rubber compounding or rubber production. The softener may be any one selected from the group consisting of petroleum oil, vegetable oil and combinations thereof, but the present invention is not limited thereto.

The petroleum oil may be any one 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, with the recent increase in environmental awareness, the content of polycyclic aromatic hydrocarbons (hereinafter referred to as "PHAs") contained in the aromatic oils is known to be highly likely to cause cancer. , TDAE (treated distillate aromatic extract) oil, mild extraction solvate (MES) oil, residual aromatic extract (RAE) oil or heavy naphthenic oil can be preferably used.

In particular, the oil used as the softener has a total content of PAHs component of 3% by weight or less, a kinematic viscosity of 15 to 25 (100 ° C, cSt), an aromatic component of the softener of 15 to 25% by weight, nap TDAE oils having 27 to 37% by weight of the ten component and 38 to 58% by weight of the paraffinic 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.

The plant oils include castor oil, cottonseed oil, linseed oil, canola oil, soybean oil, palm oil, palm oil, peanut oil, pine oil, pine tar, tall oil, corn oil, rice bran oil, safflower oil, sesame oil, olive oil, sunflower oil, palm kernel oil, camellia oil It may be used any one selected from the group consisting of jojoba oil, macadamia nut oil, saflower flower oil, tung oil and combinations thereof.

The softener is preferably used in an amount of 0 to 40 parts by weight based on 100 parts by weight of the raw material rubber, in terms of improving processability of the raw material rubber.

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

Examples of the amine type antioxidant include N-phenyl-N '- (1,3-dimethyl) -p-phenylenediamine, N- (1,3-dimethylbutyl) -N'- Phenyl-N'-isopropyl-p-phenylenediamine, N, N'-diphenyl-p-phenylenediamine, -Cyclohexyl p-phenylenediamine, N-phenyl-N'-octyl-p-phenylenediamine, and combinations thereof.

Examples of the phenolic antioxidant include phenol-based 2,2'-methylene-bis (4-methyl-6-tert-butylphenol), 2,2'- isobutylidene- Di-t-butyl-p-cresol, and combinations thereof.

As the quinoline antioxidant, 2,2,4-trimethyl-1,2-dihydroquinoline and its derivatives can be used. Specifically, 6-ethoxy-2,2,4-trimethyl- Dihydroquinoline, 6-anilino-2,2,4-trimethyl-1,2-dihydroquinoline, 6-dodecyl-2,2,4-trimethyl-1,2-dihydroquinoline and combinations thereof Any one selected from the group can be used.

As the wax, waxy hydrocarbons can be preferably used.

The anti-aging agent has a high solubility in rubber in addition to the anti-aging action, is low in volatility, inert to rubber, and does not inhibit vulcanization. It may be included in parts 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 the first step of thermomechanical treatment or kneading at a maximum temperature ranging from 110 to 190 ° C., preferably from 130 to 180 ° C. and the crosslinking system is mixed, typically less than 110 ° C., for example It can be prepared in a suitable mixer using a second step of mechanical treatment at a low temperature of 40 to 100 ℃, 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. Such rubber components include sidewalls, sidewall inserts, apex, chafers, wire coats or innerliners, and the like.

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

The tire may be a passenger car tire, a racing tire, an airplane tire, a farm tire, an off-the-road tire, a truck tire or a bus tire. In addition, the tire may be a radial tire or a bias tire, and is preferably a radial tire.

The rubber composition for tire treads of the present invention is environmentally friendly and can improve workability in the unvulcanized state, improve wet braking performance in the vulcanized state and at the same time reduce the rolling resistance.

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]

Using a composition as shown in Table 1 below to prepare a rubber composition for tire treads according to the following examples and comparative examples. The rubber composition was prepared according to a conventional method for preparing a rubber composition.

(Comparative Example 1)

The iodine adsorption specific surface area is 122 mg / g based on 100 parts by weight of the raw material rubber containing 80 parts by weight of emulsion-polymerized styrene-butadiene rubber (E-SBR 1) and 20 parts by weight of butadiene rubber (Ni-BR) prepared using a nickel catalyst. , Rubber composition with DBP oil absorption 114cc / 100g, 70 parts by weight of carbon black having a tint value of 132, 3.0 parts by weight of zinc oxide, 2.0 parts by weight of stearic acid, 2.1 parts by weight of sulfur treated with oil, 1.2 parts by weight of sulfenamide-based accelerator Was prepared and vulcanized at 168 ° C. to prepare a rubber specimen.

(Comparative Example 2)

A rubber specimen was prepared in the same manner as in the comparative example, except that an emulsion-polymerized styrene-butadiene rubber (E-SBR 2) containing an oil having a low PAH content was used in the comparative example.

(Example 1)

50 parts by weight of emulsion polymerized styrene-butadiene rubber (E-SBR 2) containing oil having a low PAH content, 20 parts by weight of Si-coupled solution-polymerized styrene-butadiene rubber, and butadiene rubber prepared using a nickel catalyst A rubber composition was prepared by blending 35 parts by weight of highly dispersible silica, 40 parts by weight of carbon black, and a silane coupling agent for the miscibility of silica and rubber with respect to 100 parts by weight of the raw material rubber including 30 parts by weight. To prepare a rubber specimen.

The Si-coupled solution polymerized styrene-butadiene rubber has a styrene content of 40% by weight, a vinyl content of butadiene is 28% by weight, a glass transition temperature of -33 ° C, and a Mooney viscosity of 75.

The highly dispersible silica has a nitrogen adsorption specific surface area of 170 m ² / g and a CTAB adsorption specific surface area of 160 m ² / g.

(Example 2)

Rubber specimens were carried out in the same manner as in Example 1 except that carbon black, which is advantageous in processability and low fuel efficiency, having an iodine adsorption specific surface area of 90 mg / g, a DBP oil absorption of 122 cc / 100 g, and a tint value of 111 was used. Was prepared.

Compounding agent Comparative Example 1 Comparative Example 2 Example 1 Example 2 E-SBR 1 80 - - - E-SBR 2 - 80 50 50 S-SBR - - 20 20 Ni-BR 20 20 30 30 Silica - - 35 35 Carbon black A 75 75 40 - Carbon black B - - - 40 Silane coupling agent - - 5.5 5.5 Zinc oxide 3 3 3 3 Stearic acid 2 2 2 2 brimstone 2.1 2.1 2.1 2.1 accelerant 1.2 1.2 1.2 1.2

(Unit: parts by weight)

The properties of the emulsion polymerization styrene-butadiene rubber used in Table 1 are summarized in Table 2 below.

SBR type Styrene content
(weight%) Weight average
Molecular Weight Tg (占 폚) Extended Oil type PAH content in oil E-SBR 1 23.5 760,000 -52 A # 2 Greater than 3% by weight E-SBR 2 23.5 890,000 -54 TDAE 3 wt% or less

In Table 2, the TDAE oil has a total amount of the eight PAH substances is 3% by weight or less, the kinematic viscosity is 20 (100 ℃, cSt), the content of the aromatic component is 20% by weight, the content of the naphthenic component 32% by weight, content of paraffinic component is 48% by weight, A # 2 oil has a total amount of the above 8 PAH materials in excess of 3% by weight, kinematic viscosity of 18 (100 ° C., cSt), aromatic component The content of is 40% by weight, the content of the naphthenic component is 30% by weight, and the content of the paraffinic component is 25% by weight.

Experimental Example: Measurement of Physical Properties of Prepared Rubber Composition

The physical properties of the rubber specimens prepared in the above Examples and Comparative Examples were measured, and the results are shown in Table 3 below.

Compounding agent Comparative Example 1 Comparative Example 2 Example 1 Example 2 Hardness (Shore A) 64 64 65 64 300% modulus (kgf / cm ² ) 112 115 112 118 Elongation (%) 482 460 496 483 Machining performance 100 101 86 103 Braking performance 100 101 104 104 Low fuel consumption performance 100 106 120 127

In Table 3, physical properties were measured by the following method.

1) Hardness is the value measured by Shore A type hardness tester, and the modulus measurement was tested by tensile tester manufactured by Instron by cutting the specimen into dumbbell shape, and elongation rate is the strain value from the tensile tester until the test piece is It measured by the method represented by%.

2) Braking and low fuel consumption performance was indexed by 0% tanδ and 60 ℃ tanδ values by 0.5% strain, 10Hz, and temp sweep with Rheometrics Dynamic Spectrometer (RDS).

3) Machining performance was extruded at a pressure of 200kgf at 110 ℃ with a fluid meter (Volume) was indexed. Larger index values indicate better performance.

Referring to Table 3, as in Comparative Examples 1 and 2, E-SBR 1 and E-SBR 2 exhibit different performances in the rubber composition due to different glass transition temperatures (Tg) due to differences in components. It can be seen. In the case of the E-SBR 2 it can be seen that the glass transition temperature is lower than the E-SBR 1 in terms of fuel efficiency performance. This is shown well in the performance test results of Comparative Examples 1 and 2 of Table 3.

Example 1 utilizes the advantages of E-SBR 2 while blending surface-modified highly dispersible silica and carbon black and introducing Si-coupled solution-polymerized styrene-butadiene rubber to maximize low fuel efficiency. It can be seen that the reduced.

In addition, it can be seen that in Example 2, by introducing carbon black, which is advantageous in processability and low fuel efficiency, improved results can be obtained not only in processability but also in low fuel efficiency.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of right.

Claims (6)

40 to 80 parts by weight of emulsion polymerized styrene-butadiene rubber (E-SBR),
10 to 40 parts by weight of Si-coupled solution polymerized styrene-butadiene rubber (S-SBR), and
10-30 parts by weight of nickel butadiene rubber having a sheath content of 96% by weight or more and a glass transition temperature of -105 to -110 ° C.
Raw material rubber containing 100 parts by weight,
30 to 50 parts by weight of silica, and
Contains 30 to 50 parts by weight of carbon black,
The Si-coupled solution polymerized styrene-butadiene rubber has a styrene content of 30 to 50% by weight, a vinyl content of butadiene is 20 to 40% by weight, a glass transition temperature of -25 to -35 ° C, and The rubber composition for tire treads having a viscosity of 75 to 85. delete The method of claim 1,
The silica has a nitrogen adsorption specific surface area of 155 to 185 m ² / g, CTAB adsorption specific surface area of 150 to 170 m ² / g rubber composition for a tire tread. The method of claim 1,
The carbon black has a iodine adsorption specific surface area of 85 to 95 mg / g, DBP oil absorption amount of 117 to 127 cc / 100 g, the tint value of 107 to 115 rubber composition for tire tread. The method of claim 1,
The emulsion-polymerized styrene-butadiene rubber has a polycyclic aromatic hydrocarbon (PAH) component of 3 wt% or less, a kinematic viscosity of 15 to 25 (100 ° C., cSt), an aromatic component of 15 to 25 wt%, and a naphthenic component of 27 To 37% by weight and paraffin-based components comprising 38 to 58% by weight of a softener for a tire tread. A tire manufactured using the rubber composition for tire tread according to any one of claims 1 and 3 to 5.