KR20150069672A - 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 by using the same. The rubber composition for a tire tread includes 45-60 parts by weight of carbon black having iodine adsorption of 50-165 mg/g, oil adsorption specific surficial area of 90-129 cc/100g, DBP oil absorption of 105-155 cc/100g, and TINT value of 115 to 155 for 100 parts by weight of raw rubber, wherein the raw rubber includes 50-80 parts by weight of natural rubber and 20-50 parts by weight of epoxy natural rubber having glass transition temperature (Tg) of -50 to -40°C, pattern viscosity of 60 to 80, and epoxidation degree of 5-50 mol%, thereby improving braking ability on wet road of a tire, and improving low rotation resistance or mileage and durability in balance without degradation of wear 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 capable of improving wet road surface braking force of a tire and capable of improving durability performance with low rolling resistance performance or fuel consumption performance without deteriorating abrasion resistance performance and a tire made therefrom .

The tread, which is a region that is in direct contact with the ground in a vehicle, greatly dominates the performance of the tire. The rubber composition for tread affects the fuel efficiency of the vehicle due to the heat generated by the repeated deformation of the tire during running. Especially, in the case of tire tread for truck-bus, a large amount of heat is generated due to the driving characteristics under high load conditions. This is directly related to the durability of the tire, so tire fuel economy is a very important performance.

In addition, due to the implementation of the energy efficiency rating system around the world, interest in wet road surface braking power in addition to fuel consumption is increasing, and consumer demand for tire life is also given priority. However, since the performance of each tire has a characteristic of being tread-off (trade-off) due to the characteristics of a tire, any performance can not be given priority.

Therefore, it is important to balance the rotational resistance of the tire, the wet road surface braking force and the wear performance.

In the past, it has been common to add a filler called silica in order to improve the wet road surface braking force of the rubber composition for a tire tread. However, when silica is added, there is a disadvantage that the abrasion performance is relatively reduced and disadvantageous.

Further, when epoxidized natural rubber (ENR) is used as raw material rubber, there is a disadvantage that durability which is directly connected to the life of a tire for a truck-bus becomes disadvantageous. Further, a method of adding polybutadiene rubber as a method for increasing abrasion resistance has been proposed. However, polybutadiene rubber needs to be selectively used because it may be disadvantageous to wet road surface braking force depending on the synthesis method and raw material characteristics.

Therefore, it is required to develop a rubber composition for a tire tread which can improve the wet road surface braking force and the abrasion resistance performance together with the fuel efficiency of the tire.

Korean Patent Publication No. 2011-0071607 (published on June 29, 2011)

It is an object of the present invention to provide a rubber composition for a tire tread which solves the above problems, improves the braking force on a wet road surface, and can improve the durability performance in balance with low rolling resistance performance without deteriorating abrasion resistance .

Another object of the present invention is to provide a tire produced by using the rubber composition for tire tread with improved fuel consumption performance.

In order to achieve the above object, the rubber composition for a tire tread according to an embodiment of the present invention comprises 45 to 60 parts by weight of carbon black relative to 100 parts by weight of raw rubber, wherein the raw rubber is 50 to 80 weight And 20 to 50 parts by weight of an epoxidized natural rubber having a glass transition temperature (Tg) of -50 to -40 캜, a pattern viscosity of 60 to 80 and an epoxidation degree of 5 to 50 mol%, wherein the carbon black is iodine An adsorption value of 50 to 165 mg / g, an oil adsorption specific surface area of 90 to 129 cc / 100 g, an oil absorption amount of dibutyl phthalate of 105 to 155 cc / 100 g, and a tint (TINT) value of 115 to 155.

The epoxidized natural rubber may have an epoxidation degree of 20 to 40 mol%, a glass transition temperature (Tg) of -50 to -40 캜, and a pattern viscosity of 70 to 80.

The carbon black may have an iodine adsorption of 100 to 165 mg / g, an oil adsorption specific surface area of 90 to 110 cc / 100 g, a DBP oil absorption of 110 to 140 cc / 100 g and a TINT value of 130 to 150.

The rubber composition for tire tread according to claim 1, wherein the rubber composition for tire tread comprises 0.5 to 5 parts by weight of a vulcanizing agent, 0.1 to 10 parts by weight of a vulcanization accelerator, 1 to 10 parts by weight of a vulcanization accelerator, 1 to 50 parts by weight of a softening agent, 10 to 10 parts by weight of a pressure-sensitive adhesive, 0.5 to 10 parts by weight of a pressure-sensitive adhesive, and a mixture thereof.

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.

In general, silica is used as a filler with excellent grip performance for improving the wet road surface braking force of the tire. However, in the case of a rubber composition containing silica, it is difficult to apply to a tread of a truck-bus tire because there is a fear of a decrease in abrasion resistance. Further, when only epoxidized natural rubber is used, the durability performance which is directly related to the life of the tire for a truck-bus is disadvantageous.

On the contrary, in the present invention, raw rubber containing Epoxidized Natural Rubber (ENR) obtained by epoxidizing a natural rubber together with natural rubber is used, and carbon black having an optimized physical property as a filler is used in an optimum amount The present invention is characterized in that the wet road surface braking force of the tire is improved and the durability performance is improved in balance with the low rotational resistance (LRR) performance or the fuel consumption performance without deteriorating the abrasion resistance by using the rubber composition for tire tread.

That is, the rubber composition for a tire tread according to an embodiment of the present invention comprises 45 to 60 parts by weight of carbon black relative to 100 parts by weight of the raw rubber, wherein the raw rubber comprises 50 to 80 parts by weight of natural rubber, 20 to 50 parts by weight of an epoxidized natural rubber having a transition temperature (Tg) of -50 to -40 占 폚, a pattern viscosity of 60 to 80 and an epoxidation degree of 5 to 50 mol%, wherein the carbon black has an iodine adsorption value of 50 to 165 mg / g and an oil adsorption specific surface area of 90 to 129 cc / 100 g, an oil absorption amount of dibutyl phthalate (DBP) of 105 to 155 cc / 100 g, and a TINT value of 115 to 155.

In the rubber composition for a tire tread of the present invention, the raw material rubber includes an epoxidized natural rubber as a modified natural rubber together with a natural rubber.

The natural rubber can be used as long as it is generally known as natural rubber, and the place of origin and the like are not limited. The natural rubber preferably contains cis-1,4-polyisoprene as a main component, and may further contain trans-1,4-polyisoprene in accordance with required characteristics. Therefore, in addition to natural rubber containing cis-1,4-polyisoprene as a main component, natural rubber including trans-1,4-isoprene as a main component, such as balata, Rubber may also be included.

In addition, the modified natural rubber means a natural rubber modified or refined. Examples of the modified natural rubber include epoxidized natural rubber (ENR), deproteinized natural rubber (DPNR), and hydrogenated natural rubber. Among them, epoxidized natural rubber is used in the present invention.

The epoxidized natural rubber (ENR) is an epoxidized unsaturated double bond of a natural rubber (NR), and can exhibit an increased molecular cohesive force by a polar epoxy group. As a result, the glass transition temperature (Tg) is higher than that of the natural rubber, and the mechanical strength and abrasion resistance are excellent.

Specifically, the epoxidized natural rubber preferably has an epoxidation degree of 5 to 50 mol%. Here, the term "epoxidation degree" means the number of epoxidized double bonds / (the number of double bonds before epoxidation). If the degree of epoxidation of the epoxidized natural rubber is less than 5 mol%, the degree of improvement is insignificant. If the epoxidized natural rubber exceeds 50 mol%, the epoxidized natural rubber (ENR) molecular chain may be easily cleaved and the rubber may be molecularized. In addition, the miscibility is deteriorated due to an increase in the viscosity, and the vulcanization rate is too fast, which may lower moldability. In view of the remarkable effect of the present invention, it is more preferable that the degree of epoxidation is 20 to 40 mol%.

The epoxidized natural rubber (ENR) preferably has a glass transition temperature (Tg) of -50 to -40 캜 and a pattern viscosity of 60 to 80. The epoxidized natural rubber satisfying such physical property requirements is excellent in improving the braking force and wear resistance on the wet road surface. Considering the remarkable effect, it is more preferable that the epoxidized natural rubber has a glass transition temperature (Tg) of -50 to -40 캜 and a pattern viscosity of 70 to 80.

The epoxidized natural rubber (ENR) may be commercially available or may be epoxidized with natural rubber (NR). The method of epoxidizing natural rubber is not particularly limited, and conventional epoxidation methods such as chlorohydrin method, direct oxidation method, hydrogen peroxide method, alkyl hydroperoxide method, peracid method and the like can be used. For example, in the case of the over-acid method, the reaction can be carried out by reacting natural rubber with organic acids such as peracetic acid and formic acid.

The raw rubber may include 50 to 80 parts by weight and 20 to 50 parts by weight of the natural rubber and the epoxidized natural rubber, respectively. If the content of the natural rubber is less than 50 parts by weight, the resulting rubber composition may have poor heat resistance, low rotational performance, low strength, cracking on the inner surface of the tire, and the like. , The content of epoxidized natural rubber is relatively decreased, and the improvement effect is insignificant. When the content of the epoxidized natural rubber is less than 20 parts by weight, the improvement effect is insignificant. When the content of the epoxidized natural rubber is more than 50 parts by weight, heat resistance is increased and low rolling performance is lowered. There is a risk of degradation. Considering the remarkable effect, it is more preferable that the raw rubber includes 60 to 80 parts by weight and 20 to 40 parts by weight of natural rubber and epoxidized natural rubber, respectively.

The raw rubber may further include a synthetic rubber in addition to the natural rubber and the epoxidized natural rubber.

The synthetic rubber may be at least one selected from the group consisting of styrene butadiene rubber (SBR), modified styrene butadiene rubber, butadiene rubber (BR), modified butadiene rubber, chlorosulfonated polyethylene rubber, epichlorohydrin rubber, fluorine rubber, silicone rubber, (NBR), modified nitrile butadiene rubber, chlorinated polyethylene rubber, styrene ethylene butylene styrene (SEBS) rubber, ethylene propylene rubber, ethylene propylene diene (EPDM) rubber, hyaluron rubber, chloroprene rubber, ethylene Vinyl acetate rubber, acrylic rubber, hydrin rubber, vinyl benzyl chloride styrene butadiene rubber, bromomethyl styrene butyl rubber, maleic styrene butadiene rubber, carboxylic styrene butadiene rubber, epoxy isoprene rubber, maleic ethylene propylene rubber, Butadiene rubber, Rommie Ney suited polyisobutyl isoprene-co-p-methylstyrene may be a (brominated polyisobutyl isoprene-co-paramethyl styrene, BIMS), and one selected from the group consisting of.

The content of the synthetic rubber is not particularly limited and may be suitably included within a range that does not deteriorate the effect of the rubber composition for a tire tread according to the present invention.

The rubber composition for a tire tread is a reinforcing filler having an iodine adsorption of 50 to 165 mg / g and an oil adsorption specific surface area (OAN) of 90 to 129 cc / 100 g, a DBP oil absorption of 105 to 155 cc / Carbon black of 115 to 155 carbon atoms.

Silica used as a reinforcing agent in a rubber composition for a tire generally has excellent reinforcing performance, but there is a fear that the abrasion resistance of the rubber composition is lowered. On the other hand, carbon black has no fear of degradation of abrasion resistance and is superior to silica in terms of reinforcing performance. Further, the rubber composition for a tire tread according to the present invention can improve the durability performance with low rolling resistance performance or fuel consumption performance without decreasing the abrasion resistance by including the carbon black having the above-mentioned optimized physical properties .

In the carbon black, the iodine adsorption value, the oil adsorption specific surface area, the DBP oil absorption amount and the TINT value are physical properties affecting the workability, low rolling resistance performance, abrasion resistance and endurance performance of the rubber composition for tire tread, The effects according to the present invention can be obtained when the sexual requirements are satisfied at the same time. If any of these physical property requirements is not satisfied, it is difficult to obtain the improvement effect on the physical properties of the rubber composition. For example, if the DBP oil absorption of the carbon black exceeds 155 cc / 100 g under conditions satisfying all other physical properties except for the DBP oil absorption, the workability of the rubber composition may be deteriorated. On the other hand, if the DBP oil absorption is less than 105 cc / 100 g There is a possibility that the reinforcing performance by the carbon black which is the filler is lowered.

Considering the remarkable improvement effect, the carbon black has an iodine adsorption of 100 to 165 mg / g, an oil adsorption specific surface area of 90 to 110 cc / 100 g, a DBP oil absorption of 110 to 140 cc / 100 g and a TINT value of 130 to 150 May be more preferable.

In addition, it is possible to obtain the effect of the present invention, which is improved as compared with the use of carbon black having a nitrogen surface area per gram (N ₂ SA) of 30 to 300 m ² / g, in addition to the above- More preferable.

The carbon black may be selected from the group consisting of N110, N121, N134, N220, N231, N234, N242, N293, N299, S315, N326, N330, N332, N339, N343, N347, N351, N358, N375, N582, N630, N642, N650, N683, N754, N762, N765, N774, N787, N907, N908, N990 or N991.

The carbon black may be included in an amount of 45 to 60 parts by weight based on 100 parts by weight of the raw rubber in consideration of the mechanical property improving effect and the processability of the rubber composition for tire tread. When the content of the carbon black is less than 45 parts by weight, the effect of improving the mechanical properties is insignificant. When the content of the carbon black is more than 60 parts by weight, the workability of the rubber composition may decrease. In consideration of the remarkable improvement effect, it is more preferable that the carbon black is contained in an amount of 50 to 60 parts by weight based on 100 parts by weight of the raw rubber.

The rubber composition for a tire tread according to the present invention can be used for improving the physical properties of a rubber composition for a tire tread such as a vulcanizing agent, a vulcanization accelerator, a vulcanization accelerator, a softening agent, an antioxidant or a pressure- The additive may be added singly or in combination of two or more.

Specifically, as the vulcanizing agent, a metal oxide such as a sulfur vulcanizing agent, an organic peroxide, a resin vulcanizing agent, or a 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. In addition, vulcanizing agents which produce elemental sulfur or sulfur such as amine disulfide, polymer sulfur Etc. may be used.

Also, 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- (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5- Butylperoxybenzene, di-t-butylperoxy-diisopropylbenzene, t-butylperoxybenzene, 2,4-dichlorobenzoylperoxide, 1,1-dibutylperoxy- 3,3,5-trimethylsiloxane, or n-butyl-4,4-di-t-butylperoxyvalerate.

It is preferable that the vulcanizing agent is included in an amount of 0.5 to 5 parts by weight based on 100 parts by weight of the raw material rubber from the viewpoint that the raw rubber is less sensitive to heat and chemically stable.

The vulcanization accelerator refers to an accelerator that promotes the vulcanization rate or accelerates the retardation in the initial vulcanization step. Examples of the vulcanization accelerator include sulfenamide, thiazole, thiuram, thiourea, guanidine, dithiocarbamate, aldehyde-amine, aldehyde-ammonia, imidazoline, Or a combination thereof.

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

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

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

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

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

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

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

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

The vulcanization accelerator may be included in an amount of 0.1 to 10 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. Examples of the organic-based vulcanization accelerator include stearic acid, zinc stearate, palmitic acid, linoleic acid, oleic acid, lauric acid, dibutyl ammonium oleate, derivatives thereof, You can use 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 to produce favorable sulfur during the vulcanization reaction Thereby facilitating the crosslinking reaction of the rubber.

When zinc oxide and stearic acid are used together, it is preferable to use 1 to 10 parts by weight per 100 parts by weight of the raw material rubber in order to serve as an appropriate vulcanization accelerating auxiliary.

The softening agent is added to the rubber composition in order to impart plasticity to the rubber to facilitate processing or to reduce the hardness of the vulcanized rubber, and means a processing oil used for 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 not more than 3% by weight, a kinematic viscosity of not less than 95 ° C (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 1 to 50 parts by weight based on 100 parts by weight of the raw material rubber in order to improve the workability of the raw material rubber.

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, 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.

Considering the conditions such that the antioxidant has a high solubility in rubber, a low volatility, an inertness to rubber, and no inhibition of vulcanization, it is preferable that the antioxidant is used in an amount of 0.1 to 10 parts by weight, By weight.

The pressure-sensitive adhesive further improves the tack performance between the rubber and the rubber and improves the physical properties of the rubber by improving the mixing properties, dispersibility and processability of other additives such as fillers.

As the pressure-sensitive adhesive, a natural resin-based pressure-sensitive adhesive such as a rosin-based resin or a terpene-based resin and a synthetic resin-based pressure-sensitive adhesive such as a petroleum resin, a coal tar, or an alkylphenolic resin can be used.

The rosin-based resin may be any one selected from the group consisting of rosin resins, rosin ester resins, hydrogenated rosin ester resins, derivatives thereof, and combinations thereof. The terpene resin may be any one selected from the group consisting of terpene resin, terpene phenol resin, and combinations thereof.

Wherein the petroleum resin is selected from the group consisting of an aliphatic resin, an acid-modified aliphatic resin, an alicyclic resin, a hydrogenated alicyclic resin, an aromatic (C9) resin, a hydrogenated aromatic resin, a C5-C9 copolymer resin, a styrene resin, And a combination thereof.

The coal tar may be a coumarone-indene resin.

The alkylphenol resin may be a p-tert-alkylphenol formaldehyde resin and the p-tert-alkylphenol formaldehyde resin may be a p-tert-butyl-phenol formaldehyde resin, p-tert- And a combination thereof.

The pressure-sensitive adhesive may be included in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the raw material rubber. If the amount of the pressure-sensitive adhesive is less than 0.5 parts by weight based on 100 parts by weight of the raw material rubber, the adhesion performance is poor. If the amount is more than 10 parts by weight, rubber properties may be deteriorated.

The rubber composition for a tire tread may be prepared by mixing the above-mentioned components according to a conventional method. During the finishing step in which the first step of thermo-mechanical treatment or kneading and the crosslinking system are mixed, specifically at a maximum temperature of 110 to 190 占 폚, preferably at a high temperature of 130 to 180 占 폚, typically less than 110 占 폚, And a second step of mechanical treatment at a low temperature of 40 to 100 DEG C, but the present invention is not limited thereto.

The rubber composition for tire treads produced by the above method is characterized in that the composition and content of the raw rubber including natural rubber and epoxidized natural rubber and the content of carbon black optimized for the physical properties requirements are simultaneously optimized The wet road surface braking force of the tire can be improved and the durability performance can be improved in a balanced manner together with the low rotational resistance performance or the fuel consumption performance without deteriorating the abrasion resistance. Accordingly, the rubber composition for a tire tread is not limited to a tread (a tread cap and a tread base), and may be included in various rubber components constituting the tire. Said rubber components include sidewalls, sidewall inserts, apex, chafer, wire coat or inner liner.

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

The tire may be manufactured from the rubber composition for a tire tread as described above and exhibit a balanced wettability performance, a low rolling resistance performance, and a durability performance in combination with an improved wet road surface braking force.

The method of manufacturing the tire may be any method used for manufacturing a tire except for the use of the rubber composition for tire tread, and a detailed description thereof will be omitted herein. However, the tire may include a tire tread made using the rubber composition for a tire tread.

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 according to the present invention improves the braking force on the wet road surface of the tire and improves the durability performance in a balanced manner with the low rolling resistance performance without deteriorating the abrasion 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.

Examples and Comparative Examples: Preparation of Rubber Composition for Tire Tread

Were mixed in the compositions and contents as shown in Table 1 below, and mixed in a Banbury mixer to prepare a rubber composition for a tire tread.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 ENR ¹ 40 - 40 40 100 100 - 60 60 ENR ² - 40 - - - - - - - Polybutadiene rubber ³ - - - - - - 40 40 40 Natural rubber 60 60 60 60 - - 60 - - Carbon black ⁴ 45 45 - - 45 - 45 45 - Carbon black ⁵ - - 45 - - - - - - Silica ⁶ - - - 45 - 45 - - 45 Processing oil 5 5 5 5 5 5 5 5 5 Zinc oxide 4.5 4.5 4.5 4.5 4.5 4.5 4.5 4.5 4.5 Stearic acid 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 brimstone 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Vulcanization accelerator 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4

1. ENR with 20 mol% epoxidation degree, Tg of -45 ° C and a pattern viscosity of 65

2. ENR with 25 mol% epoxidation degree, Tg of -50 ° C and a pattern viscosity of 65

3. Polybutadiene rubber: Butadiene rubber (average molecular weight = 7.5 to 9.2x10 ⁵ g / mol) prepared by Neodium catalyst,

4. Carbon black having an iodine adsorption of 140 mg / g, OAN 99 cc / 100 g, DBP oil absorption of 110 cc / 100 g, and a TINT value of 130

5. Carbon black having an iodine adsorption value of 127 mg / g, an OAN of 115 cc / 100 g, a DBP oil absorption of 140 cc / 100 g, and a TINT value of 120

6. Settled silica with CTAB 161 m ² / g, BET 176 m ² / g

Test example: Measurement of physical properties

Rubber specimens were prepared using the rubber compositions for tire treads prepared in Examples 1 to 3 and Comparative Examples 1 to 6, and the rubber specimens were evaluated for various physical properties according to ASTM regulations. At this time, the figure of merit was manufactured and evaluated as a 315 / 70R22.5 standard for trucks, and the results are shown in Table 2 below.

(1) Mooney viscosity (ML1 + 4 (125?)) Was measured according to ASTM standard D1646. ML1 + 4 is a value indicating the viscosity of the unvulcanized rubber. The lower the value, the better the workability of the unvulcanized rubber.

(2) The hardness was measured by the ASTM shore-A method.

(3) 300% Modulus is the tensile strength at 300% elongation, measured according to ISO 37 standard, and the higher the value, the better the strength.

(4) The wet performance index was measured by the method of ISO 15222, and the index of Example 1 was expressed as 100 based on this. Wet performance means that the larger the value, the better the performance.

(5) The LRR figure of merit was measured by the method of ISO 28580, and the index of Example 1 was expressed as 100 based on the measurement. The larger the LRR performance, the better the performance.

(6) The durability index was measured by a method of fast dead load durability evaluation, and the index of Example 1 was expressed as 100 based on the measurement. Durability performance means that the higher the value, the better the performance.

(7) The abrasion resistance index was expressed by indexing on the basis of 100 as Example 1 after measuring the abrasion amount under a slip rate of 25% by using a rambone abrasion tester. The wear resistance performance means that the higher the value, the better the performance.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Pattern viscosity (ML1 + 4 (125 DEG C)) 65 67 66 67 70 72 66 75 78 Hardness
(Shorea) 68 64 62 60 63 59 69 65 60 300% modulus
(kgf / cm2) 138 125 120 127 109 97 145 120 105 Wet performance index 100 97 104 98 105 110 77 103 107 LRR performance index 100 98 106 99 94 103 102 95 96 Durability Performance Index 100 101 92 95 87 85 107 90 88 Abrasion
Performance index 100 97 95 93 90 80 110 104 98

As shown in Table 2 above, the rubber compositions of Examples 1 to 3 exhibited overall improved performance as compared with Comparative Examples 1 to 6. Especially, Wet and LRR and durability were improved without sacrificing abrasion resistance, Wet and LRR It is possible to confirm that it is in balance. From the above results, it can be understood that the optimum combination composition of the rubber composition according to the present invention must be satisfied in order to obtain the effect of the present invention.

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 (5)

Wherein 45 to 60 parts by weight of carbon black is contained relative to 100 parts by weight of the raw rubber,
Wherein the raw material rubber comprises 50 to 80 parts by weight of a natural rubber and 20 to 50 parts by weight of an epoxidized natural rubber having a glass transition temperature (Tg) of -50 to -40 占 폚, a pattern viscosity of 60 to 80 and an epoxidation degree of 5 to 50 mol% By weight,
Wherein the carbon black has an iodine adsorption of 50 to 165 mg / g, an oil adsorption specific surface area of 90 to 129 cc / 100 g, a DBP oil absorption of 105 to 155 cc / 100 g, and a TINT value of 115 to 155. The method according to claim 1,
Wherein the epoxidized natural rubber has an epoxidation degree of 20 to 40 mol%, a glass transition temperature (Tg) of -50 to -40 DEG C and a pattern viscosity of 70 to 80. The method according to claim 1,
Wherein the carbon black has an iodine adsorption of 100 to 165 mg / g and an oil adsorption specific surface area of 90 to 110 cc / 100 g, a DBP oil absorption of 110 to 140 cc / 100 g and a TINT value of 130 to 150. The method according to claim 1,
The rubber composition for tire tread according to claim 1, wherein the rubber composition for tire tread comprises 0.5 to 5 parts by weight of a vulcanizing agent, 0.1 to 10 parts by weight of a vulcanization accelerator, 1 to 10 parts by weight of a vulcanization accelerator, 1 to 50 parts by weight of a softening agent, 10 to 10 parts by weight of a tackifier, 0.5 to 10 parts by weight of a tackifier, and a mixture thereof. A tire produced by using the rubber composition for a tire tread according to any one of claims 1 to 4.