KR20110072403A - Rubber composition for tire tread and tire manufactured by using the same - Google Patents

Abstract

PURPOSE: A rubber composition for tire tread is provided to improve abrasion resistance without the degradation of braking ability using environment-friendly materials. CONSTITUTION: A rubber composition for tire tread comprises, based on 100 parts by weight of crude rubber, 55-75 parts by weight of silica having BET surface area of 160-180 m^2/g and DBP oil absorption of 180-200 cc/100g. The crude rubber includes: 65-85 parts by weight of a solution polymerized styrene butadiene rubber(S-SBR) in which the styrene content is 35-45 weight%, the vinyl content included in the butadiene is 32-42 weight%, and the glass transition temperature is (-30)-(-35)°C; and 15-35 parts by weight of a neodymium butadiene rubber(Nd-BR) in which the glass transition temperature is (-105)-(-110)°C, the cis-1,4-butadiene content is 98 weight% or more, and the molecular weight distribution of 2.1-3.1.

Description

RUBBER COMPOSITION FOR TIRE TREAD AND TIRE MANUFACTURED BY USING THE SAME

The present invention relates to a rubber tread rubber composition and a tire manufactured using the same, and more particularly, to a tire tread rubber composition that can greatly improve wear resistance without deterioration of braking performance while using environmentally friendly materials. It relates to a tire manufactured by.

The thickness of the tire tread is determined by the depth of the grooves imprinted on the surface of the tread, which depth directly affects braking performance and driving performance which is directly related to safety. Therefore, it is very important to improve the wear resistance of the rubber composition for tire treads so as to minimize the depth reduction of the grooves.

In addition, when the tread having excellent wear resistance is applied, the depth of the groove may be reduced, and thus, fuel efficiency may be obtained due to weight reduction of the tire. Therefore, wear resistance is very important performance for a tire.

However, braking, abrasion and rolling resistance, the most important performances of tire treads, are incompatible trade-offs, and research to solve this problem has been ongoing for a long time.

In order to solve the above problem, it is possible to improve rotational resistance and braking performance at the same time by using silica as a reinforcing filler instead of carbon black. However, due to the disadvantageous dispersibility of silica, wear performance is lowered, and overcoming the trade-off of braking performance and wear performance remains a difficult task.

 In addition, it is known that the use of rubber having a low glass transition temperature can improve tire wear performance and fuel efficiency. However, when the rubber having a low glass transition temperature is used, there is a problem in that braking performance is lowered and there is a limit in improvement of wear performance. In order to compensate for the deterioration of the braking performance, when the amount of the reinforcing filler is increased, the braking performance is improved, but the fuel efficiency is reduced.

In addition, when a small amount of carbon black with a small particle size or a large amount of carbon black with a large particle diameter is mixed in order to improve abrasion performance of a tire, the physical properties of the rubber are lowered due to dispersibility problems, and heat is generated due to the use of a large amount of reinforcing agent. It may cause over durability.

 On the other hand, although there are various kinds of softeners among the additives of the rubber composition for tire treads for passenger cars, aromatic oils are generally known to improve processability and optimum properties in refining and extrusion processes.

However, with the recent increase in environmental awareness, when the content of polycyclic aromatics (PAH) contained in aromatic oils is more than 3% by weight, it is known that cancer is likely to be caused, and the European Rubber Association (BRIC) accepts this result. In the EU, specific use restrictions are in place to prevent the sale of benzopyrenes of more than 1 mg / kg, when the total amount of eight major PAH substances is more than 10 mg / kg or when the total PAH content is more than 3% by weight. By enacting a law that will be implemented after January 1, 2010, all tire makers consider this problem to be solved urgently.

As described above, the market demands both high performance of tires and use of environmentally friendly materials, and technology for discovering environmentally friendly materials and improving tire performance using the same has emerged as a hot topic in the industry.

It is an object of the present invention to provide a rubber tread composition for tire treads that can greatly improve wear resistance without deteriorating braking performance.

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

In order to achieve the above object, according to an embodiment of the present invention, the styrene content is 35 to 45% by weight, the vinyl content contained in butadiene is 32 to 42% by weight, the glass transition temperature is -30 to -35 ℃ Phosphorus solution polymerized styrene butadiene rubber (S-SBR) 65 to 85 parts by weight, glass transition temperature is -105 to -110 ℃, content of cis 1,4-butadiene is 98% by weight or more, molecular weight distribution is 2.1 to 3.1 It provides a rubber composition for a tire tread comprising a raw material rubber containing 15 to 35 parts by weight of phosphorus neodymium butadiene rubber (Nd-BR).

The tire tread rubber composition may further include 55 to 75 parts by weight of silica having a BET surface area of 160 to 180 m ² / g and a DBP oil absorption amount of 180 to 200 cc / 100 g based on 100 parts by weight of the raw material rubber.

The tire tread rubber composition has a carbon adsorption specific surface area of 130 to 150 m ² / g, a DBP oil absorption of 120 to 140 cc / 100 g, and a tint value of 120 to 140% based on 100 parts by weight of the raw material rubber. It may further comprise 10 to 30 parts by weight of black.

The tire tread rubber composition has a content of benzo (a) pyrene (C ₂₀ H ₁₂ ) less than 1 mg / kg based on 100 parts by weight of the raw material rubber, benzo (a) pyrene, benzo (e Benzo (e) Pyrene, C ₂₀ H ₁₂ , Benzo (b) Fluoranthene, C ₂₀ H ₁₂ , Benzo (j) Fluoranthene, C ₂₀ H ₁₂ ), Benzo (a) Anthtacene, C ₂₀ H ₁₂ , Benzo (k) Fluoranthene, C ₂₀ H ₁₂ , Chrysene, C ₁₈ H ₁₂ ) and dibenzo (a, h) anthracene (C ₂₀ H ₁₂ ) are less than 10 mg / kg, the aromatic content is 15 to 25% by weight, The content of the naphthenic component is 27 to 37% by weight, the content of the paraffinic component is 38 to 58% by weight, and may further include 20 to 40 parts by weight of a softener having a kinematic viscosity of at least 95 ° C.

According to another embodiment of the present invention provides a tire manufactured using the rubber tread rubber composition.

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

The raw material rubber of the tire tread rubber composition has a styrene content of 35 to 45% by weight, a vinyl content of butadiene is 32 to 42% by weight, and a solution-polymerized styrene butadiene rubber having a glass transition temperature of -30 to -35 ° C. (S-SBR) Neodymium butadiene rubber (Nd) having 65 to 85 parts by weight and a glass transition temperature of -105 to -110 ° C, a content of cis 1,4-butadiene at least 98% by weight, and a molecular weight distribution of 2.1 to 3.1 -BR) 15 to 35 parts by weight.

In general, solution polymerized styrene butadiene rubbers are prepared by continuous and batchwise processes. The styrene butadiene rubber produced by the continuous method contains a large amount of low molecular weight material, which is disadvantageous in terms of rotational resistance compared to the styrene butadiene rubber produced by the batch method, but has excellent processability and high hysteresis loss, so that dry roads or wet Excellent braking performance on road surface.

Particularly, in the case of solution-polymerized styrene butadiene having a styrene content of 35 to 45% by weight, a vinyl content of 32 to 42% by weight of butadiene, and a glass transition temperature of -30 to -35 ° C, the styrene content has a high braking performance. This is very good, and the glass transition temperature is low, the wear performance is also excellent.

The content of the styrene butadiene rubber may be included in an amount of 65 to 85 parts by weight based on 100 parts by weight of the raw material rubber. When the content of the styrene butadiene rubber is less than 65 parts by weight, the braking performance may be low. This can be disadvantageous.

Compared to cobalt butadiene rubber (Co-BR) or nickel butadiene rubber (Ni-BR), the neodymium butadiene rubber (Nd-BR) has a narrow molecular weight distribution and linear molecular structure, and thus has low rotational hysteresis. In particular, the neodymium butadiene rubber having a glass transition temperature of -105 to -110 ° C, a cis 1,4-butadiene content of 98% by weight or more, and a molecular weight distribution of 2.1 to 3.1 has excellent rotational resistance and wear performance. This is excellent.

The neodymium butadiene may be included in an amount of 15 to 35 parts by weight based on 100 parts by weight of the raw material rubber. If the content of the neodymium butadiene is less than 15 parts by weight, the wear performance may be detrimental. This can be disadvantageous.

The raw material rubber may further include any one selected from the group consisting of natural rubber, synthetic rubber, and combinations thereof, which are generally used as raw rubber.

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

The general natural rubber may be used as long as it is known as natural rubber, and the origin and the like are not limited. The natural rubber contains cis-1,4-polyisoprene as a main agent, but may also include trans-1,4-polyisoprene depending on the required properties. Therefore, the natural rubber includes, in addition to the natural rubber containing cis-1,4-polyisoprene as a main agent, for example, a natural containing trans-1,4-isoprene as a main agent such as a balata, which is a kind of rubber of South American sapotagua. Rubber may also be included.

The modified natural rubber means a modified or refined general natural rubber. For example, the modified natural rubber may include epoxidized natural rubber (ENR), deproteinized natural rubber (DPNR), hydrogenated natural rubber, and the like.

Synthetic rubber is styrene butadiene rubber (SBR), modified styrene butadiene rubber, butadiene rubber (BR), modified butadiene rubber, chloro sulfonated polyethylene rubber, epichlorohydrin rubber, fluorine rubber, silicone rubber, nitrile rubber, hydrogenated Nitrile Rubber, Nitrile Butadiene Rubber (NBR), Modified Nitrile Butadiene Rubber, Chlorinated Polyethylene Rubber, Styrene Ethylene Butylene Styrene (SEBS) Rubber, Ethylene Propylene Rubber, Ethylene Propylene Diene (EPDM) Rubber, Hypalon Rubber, Chloroprene Rubber, Ethylene vinyl acetate rubber, acrylic rubber, hydrin rubber, vinyl benzyl chloride styrene butadiene rubber, bromo methyl styrene butyl rubber, maleic acid styrene butadiene rubber, carboxylic acid styrene butadiene rubber, epoxy isoprene rubber, maleic acid ethylene propylene rubber, carboxylic acid Nitrile Butadiene High Radish, brominated polyisobutyl isoprene-co-paramethyl styrene (brominated polyisobutyl isoprene-co-paramethyl styrene, BIMS) and combinations thereof may be any one selected from the group.

In addition to the styrene butadiene rubber and neodymium butadiene rubber by adding an environmentally friendly oil having excellent low-temperature characteristics and fuel economy performance, and including the optimum silica and carbon black as the reinforcing filler in the optimum content, while improving the braking performance and fuel efficiency performance Wear resistance can also be improved.

The silica may have a BET surface area of 160 to 180 m ² / g and a DBP (n-dibutyl phthalate) oil absorption of 180 to 200 cc / 100 g. When using silica having such characteristics, the silica has excellent braking performance and carbon. Excellent wear performance with black can be optimally realized.

The silica may be included from 55 to 75 parts by weight based on 100 parts by weight of the raw material rubber. When the content of the silica is less than 55 parts by weight, the strength of the rubber may be insufficient, and the braking performance of the tire may be reduced. When the content of the silica exceeds 75 parts by weight, the wear performance may be reduced.

The silica can be used both wet or dry method, and commercially available products such as ultra-sil VN2 (manufactured by Degussa Ag), ultra-sil VN3 (manufactured by Degussa Ag), Z1165MP (manufactured by Rhodia) or Z165GR (manufactured by Rhodia) However, the present invention is not limited thereto.

The carbon black may have a nitrogen adsorption specific surface area of 130 to 150 m ² / g, a DBP oil absorption of 120 to 140 cc / 100 g, and a tint value of 120 to 140%. In this case, excellent braking performance of silica and excellent abrasion performance of carbon black can be realized optimally.

The carbon black may be included in 10 to 30 parts by weight based on 100 parts by weight of the raw material rubber. When the content of the carbon black is less than 10 parts by weight, the reinforcing performance by the carbon black filler may be lowered, and when used in excess of 30 parts by weight, the processability of the tread rubber composition may be deteriorated.

The tire tread rubber composition may use a coupling agent to improve the dispersibility of the silica. Examples of the coupling agent include a sulfide silane compound, a mercapto silane compound, a vinyl silane compound, an amino silane compound, a glycidoxy silane compound, a nitro silane compound, a chloro silane compound, a methacryl silane compound, and a combination thereof. Any one selected from the group consisting of can be used.

The sulfide-based silane compound may be bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (4-triethoxysilylbutyl) tetrasulfide, bis (3-tri Methoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, bis (4-trimethoxysilylbutyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (2 -Triethoxysilylethyl) trisulfide, bis (4-triethoxysilylbutyl) trisulfide, bis (3-trimethoxysilylpropyl) trisulfide, bis (2-trimethoxysilylethyl) trisulfide, bis (4-trimethoxysilylbutyl) trisulfide, bis (3-triethoxysilylpropyl) disulfide, bis (2-triethoxysilylethyl) disulfide, bis (4-triethoxysilylbutyl) disulfide, bis ( 3-trimethoxysilylpropyl) disulfide, bis (2-trimethoxy Sisylethyl) disulfide, bis (4-trimethoxysilylbutyl) disulfide, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, 3-triethoxysilylpropyl-N, N-dimethyl Thiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 2-trimethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilyl Propylbenzothiazolyl tetrasulfide, 3-triethoxysilylpropylbenzothiazole tetrasulfide, 3-trimethoxysilylpropylmethacrylate monosulfide, 3-trimethoxysilylpropylmethacrylate monosulfide and combinations thereof It may be any one selected from the group consisting of.

The mercapto silane compound is 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane and combinations thereof It may be any one selected from the group consisting of. The vinyl silane compound may be any one selected from the group consisting of ethoxysilane, vinyltrimethoxysilane, and combinations thereof. The amino silane compound is 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropyltri It may be any one selected from the group consisting of methoxysilane and combinations thereof.

The glycidoxy silane compounds include γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and γ-glycidoxypropylmethyldimethoxysilane And combinations thereof may be any one selected from the group consisting of. The nitro silane compound may be any one selected from the group consisting of 3-nitropropyltrimethoxysilane, 3-nitropropyltriethoxysilane, and combinations thereof. The chloro-based silane compound is selected from the group consisting of 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 2-chloroethyltrimethoxysilane, 2-chloroethyltriethoxysilane, and combinations thereof. It can be any one.

The methacrylic silane compound is any one selected from the group consisting of γ-methacryloxypropyl trimethoxysilane, γ-methacryloxypropyl methyldimethoxysilane, γ-methacryloxypropyl dimethylmethoxysilane, and combinations thereof Can be.

In particular, as the coupling agent, bis (3-ethoxysilylpropyl) disulfide (TESPD) or bis (3-triethoxysilylpropyl) tetrasulfide (TESPT) and the like may be preferably used. Sold as Si75, and TESPD is sold by Degussa under the trade name Si69, blended with 50% carbon black.

The coupling agent is preferably used 10 to 20 parts by weight based on 100 parts by weight of the raw material rubber. When the content of the coupling agent is less than 10 parts by weight based on 100 parts by weight of the raw material rubber, rotational resistance and abrasion resistance may be disadvantageous, and when it exceeds 20 parts by weight, braking performance and workability may be detrimental.

The rubber composition for tire treads may further include a softener to impart plasticity to the rubber to facilitate processing or to lower the hardness of the vulcanized rubber. The softener may be any one selected from the group consisting of process oil, vegetable oil, and combinations thereof, but the present invention is not limited thereto.

As the processing oil, any one selected from the group consisting of paraffin processing oil, naphthenic processing oil, aromatic processing oil, and combinations thereof may be used.

However, with the recent increase in environmental awareness, when the content of polycyclic aromatic hydrocarbons (PAHs) contained in the aromatic process oil is more than 3% by weight, it is known that cancer is likely to be caused.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 processed oil used as the softener has a content of benzo (a) pyrene (C ₂₀ H ₁₂ ) of less than 1 mg / kg, and benzo (a) pyrene and benzo (e) pyrene (Benzo ( e) Pyrene, C ₂₀ H ₁₂ ), benzo (b) fluoranthene (C ₂₀ H ₁₂ ), benzo (j) fluoranthene (Benzo (j) Fluoranthene, C ₂₀ H ₁₂ ), Benzo (a) Anthtacene (C ₂₀ H ₁₂ ), Benzo (k) Fluoranthene (C ₂₀ H ₁₂ ), Chrysene, C ₁₈ H ₁₂ And dibenzo (a, h) anthracene (Dibenzo (a, h) Anthracene, C ₂₀ H ₁₂ ) is less than 10 mg / kg, the aromatic component is 15 to 25% by weight, the content of the naphthenic component The oil having 27 to 37% by weight, the content of the paraffinic component to 38 to 58% by weight, and having a kinematic viscosity of 95 ° C or higher can be preferably used.

The processing oil has excellent properties in terms of environmental factors such as the possibility of causing cancer of PAHs while improving the low temperature characteristics and fuel efficiency of the tire tread including the processing oil.

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 20 to 40 parts by weight based on 100 parts by weight of the raw material rubber in that the workability of the raw material rubber is improved. If the content of the softener is less than 20 parts by weight, the workability and braking performance may be low. If the content of the softener exceeds 40 parts by weight, the workability and wear performance may be disadvantageous.

The tire tread rubber composition may optionally further include various additives such as additional vulcanizing agents, vulcanization accelerators, vulcanization accelerators, anti-aging agents and the like. 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-based vulcanizing agents, organic peroxides, resin vulcanizing agents, and magnesium oxide may 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 4.0 parts by weight based on 100 parts by weight of the raw rubber, in that the raw 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 one 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, pentamethylenedithicarbamate 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 accelerators include, for example, an aldehyde selected from the group consisting of acetaldehyde-aniline reactants, butylaldehyde-aniline condensates, hexamethylenetetramine, acetaldehyde-ammonia reactants, 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 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. .

The inorganic vulcanization accelerator may be any one selected from the group consisting of zinc oxide (ZnO), zinc carbonate, magnesium oxide (MgO), lead oxide, potassium hydroxide, and combinations thereof. have. Examples of the organic vulcanization accelerator include stearic acid, zinc stearate, palmitic acid, linoleic acid, oleic acid, lauric acid, dibutyl ammonium oleate, derivatives thereof, and combinations thereof. Any one selected can be used.

In particular, the zinc oxide and the stearic acid may be used together as the vulcanization accelerator, in which case the zinc oxide is dissolved in the stearic acid to form an effective complex with the vulcanization accelerator, thereby releasing advantageous sulfur during the vulcanization reaction. It facilitates the crosslinking reaction of the rubber.

When using the zinc oxide and the stearic acid together may be used in 1 to 5 parts by weight and 0.5 to 3 parts by weight with respect to 100 parts by weight of the raw rubber, respectively, to serve as a suitable vulcanization accelerator.

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 amines, phenols, imidazoles, carbamic acid metal salts, and combinations thereof may be appropriately selected and used.

The anti-aging agent may be N- (1,3-dimethylbutyl) -N-phenyl-p-phenylenediamine (N- (1,3-Dimethybutyl) -N-phenyl-p-phenylenediamine, 6PPD), N-phenyl n-isopropyl-p-phenylenediamine (3PPD) and poly (2,2,4-trimethyl-1,2-dihydroquinoline (Poly (2,2) , 4-trimethyl-1,2-dihydroquinoline, RD) and a combination thereof 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 tire tread rubber composition may be prepared 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. (called “non-production” step) and the crosslinking system are mixed, Typically can be prepared in a suitable mixer using a second step (called "production" step) of mechanical treatment at a low temperature of less than 110 ° C, for example 40 to 100 ° C, but the invention is not limited thereto. .

The rubber composition for the tire tread is not limited to the tread (tread cap and tread base), and 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 can greatly improve wear resistance without degrading braking performance while using environmentally friendly materials.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice 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 Treads

(Examples and Comparative Examples)

A rubber composition for tire treads according to Examples and Comparative Examples was prepared using the composition shown in Table 1 below. The manufacture of the rubber composition for tire treads was in accordance with a conventional tire production method.

 [Table 1] (Unit: parts by weight)

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example 1 Example 2 Example 3 S-SBR 1 ⁽¹⁾ 103.13
(75) - - - - - - S-SBR 2 ⁽²⁾ - 103.13
(75) - - - - - S-SBR 3 ⁽³⁾ - - 103.13
(75) - - - - S-SBR 4 ⁽⁴⁾ - - - 103.13
(75) 103.13
(75) 103.13
(75) 103.13
(75) BR 1 ⁽⁵⁾ 25 25 25 25 - - - BR 2 ⁽⁶⁾ - - - - 25 25 25 Silica ⁽⁷⁾ 85 85 85 85 85 65 55 Carbon Black ⁽⁸⁾ 20 30 Coupling Agents ⁽⁹⁾ 15 15 15 15 15 13 12 Zinc oxide 3 3 3 3 3 3 3 Stearic acid One One One One One One One Antioxidant ⁽¹⁰⁾ 2.4 2.4 2.4 2.4 2.4 2.4 2.4 Vulcanizer ⁽¹¹⁾ 0.7 0.7 0.7 0.7 0.7 0.7 0.7 Accelerators ⁽¹²⁾ 2.2 2.2 2.2 2.2 2.2 2.2 2.2

(1) S-SBR 1: Solution-polymerized styrene butadiene rubber prepared by a continuous process having a styrene content of 24% by weight and a vinyl content of 48% by weight of butadiene. Contains 37.5 parts by weight of TDAE oil.

(2) S-SBR 2: A solution-polymerized styrene butadiene rubber prepared by a continuous process having a styrene content of 39% by weight and a vinyl content of 37% by weight of butadiene. Contains 37.5 parts by weight of A # 2 oil.

(3) S-SBR 3: A solution-polymerized styrene butadiene rubber prepared by a batch method having a styrene content of 39% by weight and a vinyl content of 37% by weight of butadiene. Contains 37.5 parts by weight of TDAE Oil.

(4) S-SBR 4: A solution-polymerized styrene butadiene rubber prepared by a continuous method having a styrene content of 39% by weight and a vinyl content of 37% by weight of butadiene. Contains 37.5 parts by weight of TDAE oil.

(5) BR 1: Nickel butadiene rubber, trade name KBR01 (Kumho Petrochemical Co., Ltd.)

(6) BR 2: Neodymium butadiene rubber, trade name CB24 (Lanxess)

(7) Silica: Precipitated silica having a BET surface area of 160 to 180 m ² / g and a DBP oil absorption of 180 to 200 cc / 100 g.

(8) Carbon Black: Carbon black having a nitrogen adsorption specific surface area of 130 to 150 m ² / g, a DBP oil absorption of 120 to 140 cc / 100 g, and a tint value of 120 to 140%.

(9) coupling agent: X-50S ^® (Evonik Degussa Co., will a mixture of ethoxy-silyl propyl) tetrasulfide carbon black in the bis (3-triethoxysilylpropyl to 50: 50 weight ratio)

(10) Antioxidant: 6PPD ^® (Unibond)

(11) vulcanizing agents: elemental sulfur.

(12) Accelerator: Sulfenax CBS ^® (manufactured by DUSLO)

In Table 1, the S-SBR contains 37.5 parts by weight of oil per 100 parts by weight of the raw material rubber (ie, 27.3% by weight of the total SBR containing oil is oil). Figures in parentheses refer to the weight of rubber, excluding oil.

* TDAE Oil: The content of benzo (a) pyrene is less than 1mg / kg, the total amount of the eight PAH substances is less than 10mg / kg, the kinematic viscosity is 98 ℃, the content of aromatic components is 20% by weight, naph The content of the ten component is 32% by weight and the content of the paraffin component is 48% by weight.

* A # 2 Oil: The content of benzo (a) pyrene is 1mg / kg or more, the total amount of the eight PAH substances is 10mg / kg or more, the kinematic viscosity is 91 ℃, the content of the aromatic component is 40% by weight , The content of the naphthenic component is 30% by weight, the content of the paraffinic component is 25% by weight.

Experimental Example: Measurement of physical properties of the manufactured rubber tread rubber composition

The Mooney viscosity, hardness, 300% modulus, viscoelasticity, etc. of the rubber composition for tire treads obtained in Examples and Comparative Examples were measured based on ASTM-related regulations, and the results are shown in Table 2 below.

TABLE 2

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example 1 Example 2 Example 3 Mooney viscosity 60 65 76 68 72 68 65 ShoreA 68 68 67 68 69 69 69 300% modulus
(MPa) 11.8 12.3 12.5 12.2 12 12.5 13 0 ℃ tanδ 0.305 0.329 0.308 0.324 0.315 0.313 0.311 60 ℃ tanδ 0.12 0.121 0.103 0.115 0.107 0.118 0.122

Mooney viscosity (ML1 + 4 (125 ° C.)) was measured according to SMS ASTM standard D1646. The Mooney viscosity is a value indicating the viscosity of the unvulcanized rubber, the lower the value, the better the workability of the unvulcanized rubber, and the higher the value, the higher the viscosity of the rubber, which indicates the poor workability.

Hardness was measured according to DIN 53505. Hardness indicates steering stability. The higher the value, the better the steering stability.

-300% Modulus (Modulus) is the tensile strength at 300% elongation, measured according to the ISO 37 standard, the higher the value shows excellent strength.

-Viscoelasticity was measured by GDS, G ", tanδ from -60 ℃ to 60 ℃ under 10Hz frequency at 0.5% strain using RDS meter. 0 ℃ tanδ shows braking characteristics. It shows the excellent performance, 60 ℃ tan δ indicates the rotational resistance characteristics, the lower the value indicates the better fuel economy performance.

In addition, a tread is manufactured using the rubber composition of the comparative examples and examples, and a tire of a 205 / 55R16 standard including the prepared tread rubber as a semi-finished product is manufactured so that braking performance of the tire on dry and wet road surfaces, The relative ratios of the rolling resistance performance and the wear resistance were measured, and the results are shown in Table 3 below.

[Table 3]

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example 1 Example 2 Example 3 Braking performance 100 103 100 102 100 100 99 Wear resistance 100 103 108 105 115 120 125 Fuel efficiency 100 100 104 102 104 101 99

Referring to Tables 2 and 3 above, when styrene butadiene rubber prepared by a continuous method having a styrene content of 39% by weight and a vinyl content of 37% by weight of butadiene is used (Comparative Example 4) And it can be seen that the braking performance is improved without significant deterioration of the wear performance compared to the case of using the same amount of vinyl and styrene butadiene rubber produced by the batch method (Comparative Example 3).

In addition, when styrene butadiene rubber prepared by the continuous method of 39% by weight of styrene and 37% by weight of vinyl contained in butadiene is used (Comparative Example 4), the styrene content is 24% by weight and butadiene It can be seen that both the braking performance and the abrasion resistance are improved compared to the case of using the styrene butadiene rubber prepared by the continuous method having a vinyl content of 48 wt% in (Comparative Example 1).

In addition, it can be seen that fuel efficiency and abrasion resistance are greatly improved when neodymium butadiene rubber is used (Example 1) compared with nickel butadiene rubber (Comparative Example 4) without a significant decrease in braking performance.

In addition, when an appropriate amount of carbon is further added as a reinforcing filler (Examples 2 and 3), the wear resistance is significantly improved without deterioration of braking performance as compared with the case of using only silica (Example 1). there was.

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 rights.

Claims (5)

65 to 85 parts by weight of solution-polymerized styrene butadiene rubber (S-SBR) having a styrene content of 35 to 45% by weight, a vinyl content of 32 to 42% by weight of butadiene, and a glass transition temperature of -30 to -35 ° C. And 15 to 35 parts by weight of neodymium butadiene rubber (Nd-BR) having a glass transition temperature of -105 to -110 ° C, a cis 1,4-butadiene content of 98% by weight or more and a molecular weight distribution of 2.1 to 3.1 Raw material rubber containing Rubber composition for a tire tread comprising a. The method of claim 1, The tire tread rubber composition is based on 100 parts by weight of the raw material rubber The rubber composition for a tire tread having a BET surface area of 160 to 180 m ² / g and further comprising 55 to 75 parts by weight of silica having a DBP oil absorption of 180 to 200 cc / 100 g. The method of claim 1, The tire tread rubber composition is based on 100 parts by weight of the raw material rubber Rubber for tire treads further comprising 10 to 30 parts by weight of carbon black having a nitrogen adsorption specific surface area of 130 to 150 m ² / g, a DBP oil absorption of 120 to 140 cc / 100 g, and a tint value of 120 to 140%. Composition. The method of claim 1, The tire tread rubber composition is based on 100 parts by weight of the raw material rubber Benzo (a) pyrene (C ₂₀ H ₁₂ ) is less than 1 mg / kg, Benzo (e) pyrene, Benzo (e) Pyrene, C ₂₀ H ₁₂ , Benzo (b) Fluoranthene, C ₂₀ H ₁₂ , Benzo (j) fluorane Benzo (j) Fluoranthene, C ₂₀ H ₁₂ , Benzo (a) Anthtacene, C ₂₀ H ₁₂ , Benzo (k) Fluoranthene, C ₂₀ H ₁₂ ), Chrysene (C ₁₈ H ₁₂ ) and dibenzo (a, h) anthracene (Dibenzo (a, h) Anthracene, C ₂₀ H ₁₂ ) are less than 10 mg / kg, The content of the aromatic component is 15 to 25% by weight, The content of the naphthenic component is 27 to 37% by weight, The content of paraffin component is 38 to 58% by weight, Kinematic viscosity is 95 ℃ or more A rubber composition for a tire tread further comprising 20 to 40 parts by weight of a softener. A tire manufactured using the rubber composition for tire tread according to any one of claims 1 to 4.