KR102348847B1 - 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, and more particularly, to 100 parts by weight of a raw rubber containing solution-polymerized styrene-butadiene rubber; 2 to 15 parts by weight of natural oil; 15 to 30 parts by weight of resin; Silica 80 to 110 parts by weight; and a rubber composition for a tire tread comprising 2 to 10 parts by weight of carbon black, and a tire manufactured using the same.

Description

A rubber composition for a tire tread and a tire manufactured using the same

The present invention relates to a rubber composition for a tire tread and a tire manufactured using the same, and more particularly, to a tire tread rubber used in summer by significantly improving rolling resistance and abrasion resistance while maintaining braking performance on a wet road surface. It relates to a composition and a tire manufactured using the same.

Since 2017, the Worldwide Harmonized Light Vehicle Test Procedure (WLTP) has been newly established to measure fuel efficiency, and as environmental issues such as global warming and fine dust have become major issues around the world, the automobile industry is making great efforts to improve fuel efficiency.

In order to reduce the exhaust gas generated by the vehicle, it is essential to increase the fuel efficiency of the vehicle. Therefore, it is also necessary to increase the fuel efficiency in the tire in contact with the ground of the vehicle, and there are two major methods for improving the fuel efficiency in the tire. First, it is a method of reducing the rolling resistance of the tire, and secondly, it is a method of improving the abrasion resistance. Developing tires with reduced rolling resistance has been the key to fuel efficiency improvement technology in the past, and using tread rubber with better abrasion resistance can reduce tire weight and improve fuel efficiency by reducing tread thickness. This method has recently been mainly used to improve fuel efficiency.

However, in a tire, there is a trade-off tendency in that if one performance is improved, the other performance is disadvantageous. When styrene-butadiene rubber having a low glass transition temperature (Tg) is used to improve abrasion resistance in tread rubber, there is a problem in that braking performance on a wet road surface is disadvantageous. In particular, when a low Tg functional styrene-butadiene rubber is used, the compatibility between the styrene-butadiene rubber, butadiene rubber, fillers and additives is not good, so processability for mass production has become a problem. Conventionally, a technique of using a mixture of high Tg functional styrene-butadiene rubber and low Tg butadiene rubber has been used, but there is a problem that it is difficult to overcome the trade-off between fuel economy performance, abrasion resistance performance, and braking performance on a wet road surface. .

Recently, as the performance demanded by automobile manufacturers and consumers has improved, the need to improve the rolling resistance and abrasion resistance while maintaining the braking performance is emerging. It continues.

Accordingly, it is an object of the present invention to provide a rubber composition for a tire tread that can improve rolling resistance performance and abrasion resistance performance while maintaining braking performance on a wet road surface, and used in summer.

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

A rubber composition for a tire tread according to an aspect of the present invention comprises: 100 parts by weight of a raw rubber containing solution-polymerized styrene-butadiene rubber (S-SBR); 2 to 15 parts by weight of natural oil; 15 to 30 parts by weight of resin; Silica 80 to 110 parts by weight; and 2 to 10 parts by weight of carbon black.

In this case, the raw rubber has a styrene content of 10 to 30 wt%, a vinyl content in butadiene of 10 to 40 wt%, a glass transition temperature (Tg) of -70 to -50 °C, and a weight average molecular weight of 300,000 to 35 to 60 parts by weight of a first solution-polymerized styrene-butadiene rubber (S-SBR) having a molecular weight distribution of 1.5 to 2.0 and 1,000,000 g/mol; The styrene content is 20 to 40 wt%, the vinyl content in butadiene is 25 to 45 wt%, the glass transition temperature (Tg) is -30 to -10 °C, and the weight average molecular weight is 1,000,000 to 1,500,000 g/mol, molecular weight 10 to 30 parts by weight of the second solution polymerization styrene-butadiene rubber (S-SBR) having a distribution of 2.0 to 2.5; and a styrene content of 10 to 30% by weight, a vinyl content of 30 to 55% by weight in butadiene, a glass transition temperature (Tg) of -50 to -25°C, and a weight average molecular weight of 200,000 to 700,000 g/mol, The molecular weight distribution may include 20 to 45 parts by weight of the third solution-polymerized styrene-butadiene rubber (S-SBR) having a molecular weight of 1.5 to 2.5.

And, the raw material rubber, 2 to 10 parts by weight of natural rubber; and 90 to 98 parts by weight of the solution-polymerized styrene-butadiene rubber (S-SBR).

In addition, the natural oil may contain 60 to 90% by weight of unsaturated fatty acids, and the weight ratio of linoleic acid to oleic acid in the unsaturated fatty acids may be 0.5 to 5.

Here, the natural oil may be at least one selected from the group consisting of sunflower oil, soybean oil, canola oil, and grape seed oil.

In addition, the resin may have a softening point of 20 to 160° C. and a weight average molecular weight of 40 to 2,000 g/mol.

In addition, the silica may have a nitrogen adsorption amount of 160 to 180 m ² /g, a CTAB value of 150 to 170 m ² /g, and a DBP oil absorption amount of 180 to 200 cc/100g.

Meanwhile, a tire according to another aspect of the present invention is manufactured using the above-described rubber composition for a tire tread according to the present invention.

According to the present invention, since it contains both natural oil and resin in a specific content, rubber compatibility can be improved, rolling resistance performance and abrasion resistance performance are improved, and braking performance on a wet road surface can also be improved. can

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

A rubber composition for a tire tread according to an aspect of the present invention comprises: 100 parts by weight of a raw rubber containing solution-polymerized styrene-butadiene rubber (S-SBR); 2 to 15 parts by weight of natural oil; 15 to 30 parts by weight of resin; Silica 80 to 110 parts by weight; and 2 to 10 parts by weight of carbon black.

The raw rubber may include natural rubber in addition to solution-polymerized styrene-butadiene rubber.

The solution-polymerized styrene-butadiene rubber has a styrene content of 10 to 30 wt%, a vinyl content in butadiene of 10 to 40 wt%, a glass transition temperature (Tg) of -70 to -50 °C, and a weight average molecular weight of 35 to 60 parts by weight of a first solution-polymerized styrene-butadiene rubber (S-SBR) having a molecular weight distribution of 300,000 to 1,000,000 g/mol and 1.5 to 2.0; The styrene content is 20 to 40 wt%, the vinyl content in butadiene is 25 to 45 wt%, the glass transition temperature (Tg) is -30 to -10 °C, and the weight average molecular weight is 1,000,000 to 1,500,000 g/mol, molecular weight 10 to 30 parts by weight of the second solution polymerization styrene-butadiene rubber (S-SBR) having a distribution of 2.0 to 2.5; and a styrene content of 10 to 30% by weight, a vinyl content of 30 to 55% by weight in butadiene, a glass transition temperature (Tg) of -50 to -25°C, and a weight average molecular weight of 200,000 to 700,000 g/mol, The molecular weight distribution may include 20 to 45 parts by weight of the third solution-polymerized styrene-butadiene rubber (S-SBR) having a molecular weight of 1.5 to 2.5.

In this case, the first solution-polymerized styrene-butadiene rubber and the third solution-polymerized styrene-butadiene rubber may be manufactured by a method of manufacturing in a batch reactor, and the second solution-polymerized styrene-butadiene rubber is It may be manufactured by a method manufactured in a continuous reactor.

The rubbers may have a difference in weight average molecular weight distribution depending on the manufacturing method, and are effective in that they can complement each other's extrusion processability through simultaneous use.

The first solution-polymerized styrene-butadiene rubber has a low Tg and is advantageous in terms of abrasion resistance and rotational resistance, but may be disadvantageous in terms of processability and braking performance. In addition, the second solution-polymerized styrene-butadiene rubber has a high Tg and is advantageous in terms of braking performance, but is not good in terms of abrasion resistance, and compatibility with the first solution-polymerized styrene-butadiene rubber is not good.

Accordingly, the first solution-polymerized styrene-butadiene rubber and the second solution-polymerized styrene-butadiene rubber have intermediate physical properties and a third solution-polymerized styrene-butadiene having a specific content capable of serving as a binder between the two rubbers. By further mixing the rubber, it is possible to obtain a rubber composition for a tire tread capable of improving the compatibility between the rubbers, maintaining braking performance on a wet road surface, and improving rolling resistance and abrasion resistance.

The raw rubber may include only solution-polymerized styrene-butadiene rubber, 2 to 10 parts by weight of natural rubber; and 90 to 98 parts by weight of the solution-polymerized styrene-butadiene rubber (S-SBR).

When the natural rubber is contained in an amount of less than 2 parts by weight, the natural rubber having a crystallized structure has insignificant properties, and when it exceeds 10 parts by weight, a disadvantageous problem may occur in terms of compatibility with styrene-butadiene rubber.

The natural rubber may be a general natural rubber or a modified natural rubber. As the general natural rubber, any known natural rubber may be used, and the country of origin is not limited. The natural rubber mainly includes cis-1,4-polyisoprene, but may also include trans-1,4-polyisoprene according to required properties. Therefore, in the natural rubber, in addition to natural rubber containing cis-1,4-polyisoprene as a main component, natural rubber containing trans-1,4-isoprene as a main component, such as Valata, a type of rubber of the Sapotaceae family from South America, as a main component It may also include rubber.

On the other hand, the natural oil, based on 100 parts by weight of the raw rubber, is characterized in that it contains 2 to 15 parts by weight. When the natural oil is included in an amount of less than 2 parts by weight, the processability is reduced when mixing the compound due to the increase in the pattern viscosity. Problems may occur, and if it exceeds 15 parts by weight, there may be problems in which extrusion processability is deteriorated due to a decrease in pattern viscosity, and problems in which rolling resistance and braking performance on a wet road surface are excessively deteriorated.

In this case, the natural oil may contain 60 to 90% by weight of an unsaturated fatty acid, and a weight ratio of linoleic acid to oleic acid in the unsaturated fatty acid may be 0.5 to 5.

When the weight ratio of the oleic acid to the linoleic acid is less than 0.5, the wear resistance performance is excellent, but a trade-off may occur in terms of braking and rolling resistance performance on a wet road surface, and the weight ratio exceeds 5. Conversely, if included, the trade-off phenomenon may be insignificant, but the abrasion resistance performance effect may be insignificant.

The natural oil may be at least one selected from the group consisting of sunflower oil, soybean oil, canola oil and grape seed oil. And, it is advantageous in terms of improving the fluidity of the synthesized rubber composition to use one having a weight average molecular weight of 1,000 g/mol or more and a Tg of -70 to -40°C, and ultimately it is preferable in terms of improving the wear performance of the tire.

On the other hand, the resin is characterized in that it is included in an amount of 15 to 30 parts by weight based on 100 parts by weight of the raw rubber. Braking performance on a wet road surface may be improved, but it may be disadvantageous to rolling resistance rather than an effect of improving braking performance on a wet road surface.

In this case, the resin has a softening point of 20 to 160° C., and a weight average molecular weight of 40 to 2,000 g/mol, which improves compatibility with rubber and is advantageous in improving reinforcing properties.

The resin may be at least one selected from the group consisting of a hydrocarbon resin, a terpene-based resin, a coumarone indene resin, an aromatic petroleum-based resin, and an alphamethylstyrene resin.

According to the present invention, it is possible to improve the compatibility of rubber by including both a specific content of natural oil and a specific content of resin, and not only improve rolling resistance performance and abrasion resistance performance, but also improve braking performance on a wet road surface can do it

Meanwhile, in the present invention, as a reinforcing filler, silica and carbon black were used in combination. The silica is included in 80 to 110 parts by weight based on 100 parts by weight of the raw rubber, and the carbon black is characterized in that it is included in 2 to 10 parts by weight. There is a problem, and when it exceeds 110 parts by weight, there is a problem that wear resistance performance and fuel efficiency performance are disadvantageous. In addition, when the content of the carbon black is less than 2 parts by weight, the reinforcing effect becomes insignificant, and when it exceeds 10 parts by weight, the rotational resistance performance may deteriorate.

The silica has a nitrogen adsorption amount of 160 to 180 m ² /g, and a cetyl trimethyl ammonium bromide (CTAB) adsorption value of 150 to 170 m ² /g, and a DBP oil absorption of 180 to 200 cc/100g may be used.

As the silica, all of those produced by a wet method or a dry method such as precipitated silica can be used, and commercially available products include Ultrasil 7000Gr (manufactured by Evonik), Ultrasil 9000Gr (manufactured by Evonik), Zeosil 1165MP (manufactured by Rhodia), Zeosil 200MP (manufactured by Rhodia) Alternatively, Zeosil 195HR (manufactured by Rhodia) or the like can be used.

The carbon black may have a nitrogen adsorption specific surface area (N2SA) of 30 to 300 m ² /g, and an n-dibutyl phthalate (DBP) oil absorption of 60 to 180 cc/100g, but in the present invention This is not limited thereto.

When the nitrogen adsorption specific surface area of the carbon black ^{exceeds 300 m 2} /g, the processability of the rubber composition for a tire may be disadvantageous, and ^{if it is less than 30 m 2} /g, the reinforcing performance by the carbon black as a filler may be disadvantageous. In addition, if the DBP oil absorption amount of the carbon black exceeds 180 cc/100g, the processability of the rubber composition may decrease, and if it is less than 60 cc/100g, the reinforcing performance by the carbon black as a filler may be disadvantageous.

Representative examples of the carbon black include N110, N121, N134, N220, N231, N234, N242, N293, N299, S315, N326, N330, N332, N339, N343, N347, N351, N358, N375, N539, N550, N582 , N630, N642, N650, N683, N754, N762, N765, N774, N787, N907, N908, N990 or N991.

In addition, a coupling agent may be additionally included to improve dispersibility of the reinforcing filler.

The coupling agent includes a sulfide-based silane compound, a mercapto-based silane compound, a vinyl-based silane compound, an amino-based silane compound, a glycidoxy-based silane compound, a nitro-based silane compound, a chloro-based silane compound, a methacrylic silane compound, and combinations thereof Any one selected from the group consisting of may be used, and a sulfide-based silane compound may be preferably used.

The sulfide-based silane compound is 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-trimethoxysilylethyl)disulfide, bis(4-trimethoxysilylbutyl)disulfide, 3-trimethoxysilylpropyl-N,N-dimethylthiocarbamoyl Tetrasulfide, 3-triethoxysilylpropyl-N,N-dimethylthiocarbamoyltetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyltetrasulfide, 2-trimethoxysilylethyl-N ,N-dimethylthiocarbamoyltetrasulfide, 3-trimethoxysilylpropylbenzothiazolyltetrasulfide, 3-triethoxysilylpropylbenzothiazoletetrasulfide, 3-trimethoxysilylpropylmethacrylate monosulfide, 3 - It may be any one selected from the group consisting of trimethoxysilylpropyl methacrylate monosulfide and combinations thereof.

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-based silane compound may be any one selected from the group consisting of ethoxysilane, vinyltrimethoxysilane, and combinations thereof. The amino-based 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 compound is γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldimethoxysilane And it may be any one selected from the group consisting of combinations thereof. The nitro-based 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. may be any one of

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

The coupling agent may be included in an amount of 5 to 20 parts by weight based on 100 parts by weight of the raw rubber. When the content of the coupling agent is less than 5 parts by weight, the dispersibility improvement of the reinforcing filler is insufficient, so that the processability of the rubber or low fuel consumption performance may be reduced. Because it is too strong, fuel economy performance may be excellent, but braking performance may be very poor.

Meanwhile, the rubber composition for a tire tread of the present invention may optionally further include various additives such as an additional vulcanizing agent, vulcanization accelerator, vulcanization accelerator, anti-aging agent or processing aid. Any of the above various additives may be used as long as they are commonly used in the field to which the present invention pertains, and their content is not particularly limited as it depends on a compounding ratio used in a conventional rubber composition for a tire tread.

As the vulcanizing agent, a sulfur-based vulcanizing agent may be preferably used. The sulfur-based vulcanizing agent may be an inorganic vulcanizing agent such as powdered sulfur (S), insoluble sulfur (S), precipitated sulfur (S), colloidal sulfur. As the sulfur-based vulcanizing agent, specifically elemental sulfur or a vulcanizing agent for generating sulfur, for example, amine disulfide, polymeric sulfur, and the like may be used.

It is preferable that the vulcanizing agent be included in an amount of 0.5 to 2.0 parts by weight based on 100 parts by weight of the raw rubber in terms of making the raw rubber less sensitive to heat and chemically stable as an appropriate vulcanizing effect.

The vulcanization accelerator refers to an accelerator that promotes a vulcanization rate or a delayed action in the initial vulcanization stage.

Examples of the vulcanization accelerator include sulfenamide-based, thiazole-based, thiuram-based, thiourea-based, guanidine-based, dithiocarbamic acid-based, aldehyde-amine-based, aldehyde-ammonia-based, imidazoline-based, xanthate-based and their Any one selected from the group consisting of combinations may be used.

Examples of the sulfenamide-based vulcanization accelerator include N-cyclohexyl-2-benzothiazolesulfenamide (CBS), N-tert-butyl-2-benzothiazolesulfenamide (TBBS), N,N-dicyclohexyl Any one selected from the group consisting of -2-benzothiazolesulfenamide, N-oxydiethylene-2-benzothiazolesulfenamide, N,N-diisopropyl-2-benzothiazolesulfenamide, and combinations thereof of sulfenamide compounds may be used.

Examples of the thiazole-based vulcanization accelerator include 2-mercaptobenzothiazole (MBT), dibenzothiazoledisulfide (MBTS), sodium salt of 2-mercaptobenzothiazole, 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-based compound selected from the group consisting of ethyl4-morpholinothio)benzothiazole and combinations thereof may be used.

The thiuram-based vulcanization accelerator includes, for example, tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide, tetramethylthiuram monosulfide, dipentamethylenethiuram disulfide, dipentamethylenethiuram monosulfide, and dipentamethylene. Any one thiuram-based compound selected from the group consisting of thiuram tetrasulfide, dipentamethylene thiuram hexasulfide, tetrabutyl thiuram disulfide, pentamethylene thiuram tetrasulfide, and combinations thereof may be used.

The thiourea-based vulcanization accelerator is, for example, any one selected from the group consisting of thiacarbamide, diethylthiourea, dibutylthiourea, trimethylthiourea, diorthotolylthiourea, and combinations thereof. compounds may be used.

As the guanidine-based vulcanization accelerator, for example, any one guanidine-based selected from the group consisting of diphenylguanidine (DPG), diorthotolylguanidine, triphenylguanidine, orthotolylbiguanide, diphenylguanidinephthalate, and combinations thereof compounds may be used.

Examples of the dithiocarbamic acid-based vulcanization accelerator include zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, Zinc dibutyldithiocarbamate, zinc diamyldithiocarbamate, zinc dipropyldithiocarbamate, complex salt of zinc pentamethylenedithiocarbamate and piperidine, hexadecylisopropyldithiocarbamate zinc, octadecyl Zinc isopropyldithiocarbamate, zinc dibenzyldithiocarbamate (ZBEC), sodium diethyldithiocarbamate, piperidine pentamethylenedithiocarbamate, selenium dimethyldithiocarbamate, diethyldithiocarbamate Any one dithiocarbamic acid-based compound selected from the group consisting of tellunium acid, cadmium diamyldithiocarbamate, and combinations thereof may be used.

The aldehyde-amine-based or aldehyde-ammonia-based vulcanization accelerator is, 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 may be used.

As the imidazoline-based vulcanization accelerator, for example, an imidazoline-based compound such as 2-mercaptoimidazoline can be used. compounds may be used.

The vulcanization accelerator may be included in an amount of 1.0 to 2.5 parts by weight based on 100 parts by weight of the raw rubber in order to maximize productivity and rubber properties through acceleration of the vulcanization rate.

On the other hand, the vulcanization accelerator is a compounding agent used in combination with the vulcanization accelerator to perfect the accelerating effect, and any one selected from the group consisting of an inorganic vulcanization accelerator, an organic vulcanization accelerator and a combination thereof may be used. can

As the inorganic vulcanization accelerator, any one selected from the group consisting of zinc oxide (ZnO), zinc carbonate, magnesium oxide (MgO), lead oxide, potassium hydroxide, and combinations thereof can be used. have. The organic-based 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. Any one can be used.

In particular, the zinc oxide and the stearic acid can be used together as the vulcanization accelerator, and in this case, the zinc oxide is dissolved in the stearic acid to form an effective complex with the vulcanization accelerator to release advantageous sulfur during the vulcanization reaction It facilitates the crosslinking reaction of rubber by making it.

When the zinc oxide and the stearic acid are used together, 1 to 5 parts by weight and 0.5 to 3 parts by weight 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 an appropriate vulcanization accelerator. When the content of the zinc oxide and the stearic acid is less than the above range, the vulcanization rate is slow and productivity may be reduced.

On the other hand, the antioxidant is an additive used to stop the chain reaction in which the tire is automatically oxidized by oxygen. As the antioxidant, any one selected from the group consisting of amine-based, phenol-based, quinoline-based, imidazole-based, carbamic acid metal salts, waxes, and combinations thereof may be appropriately selected and used.

The amine-based antioxidants include N-phenyl-N'-(1,3-dimethyl)-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine ( 6PPD), N-phenyl-N'-isopropyl-p-phenylenediamine (3PPD), N,N'-diphenyl-p-phenylenediamine, N,N'-diaryl-p-phenylenediamine, Any one selected from the group consisting of N-phenyl-N'-cyclohexyl p-phenylenediamine, N-phenyl-N'-octyl-p-phenylenediamine, and combinations thereof may be used. The phenolic antioxidants include phenolic 2,2'-methylene-bis(4-methyl-6-tert-butylphenol), 2,2'-isobutylidene-bis(4,6-dimethylphenol), 2 Any one selected from the group consisting of ,6-di-t-butyl-p-cresol and combinations thereof may be used. As the quinoline-based antioxidant, 2,2,4-trimethyl-1,2-dihydroquinoline (RD) and its derivatives may be used, and specifically, 6-ethoxy-2,2,4-trimethyl-1, 2-dihydroquinoline, 6-anilino-2,2,4-trimethyl-1,2-dihydroquinoline, 6-dodecyl-2,2,4-trimethyl-1,2-dihydroquinoline, and their Any one selected from the group consisting of combinations may be used. Preferably, waxy hydrocarbon may be used as the wax.

In addition, in consideration of conditions such as that the antioxidant should have high solubility in rubber, low volatility, inert rubber, and not inhibit vulcanization, in addition to the anti-aging action, 1 to 100 parts by weight of the raw rubber to 5 parts by weight.

Meanwhile, the rubber composition for a tire tread is not limited to the tread part, and may be included in various rubber components constituting the tire, such as a tread (tread cap and tread base). The rubber component may include a sidewall, a sidewall insert, an apex, a chafer, a wire coat or an inner liner.

Meanwhile, a tire according to another aspect of the present invention is characterized in that it is manufactured using the above-described rubber composition for a tire tread.

The tire may be a tire for a passenger car, a tire for racing, an airplane tire, a tire for an agricultural machine, 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, preferably a radial tire, and may be a summer tire.

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. However, the present invention may be embodied in several different forms and is not limited to the embodiments described herein.

[Production Example: Preparation of rubber composition for tire tread]

Rubber compositions for tire treads according to the following Comparative Examples and Examples were prepared using the compositions shown in Table 1 below. The rubber composition was prepared according to a conventional method for preparing a rubber composition.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 raw rubber natural rubber 20 20 - - - 1st S-SBR 30 30 45 45 45 2nd S-SBR - - 10 20 30 3rd S-SBR 50 50 45 35 25 carbon black 5 5 5 5 5 silica 90 90 90 90 90 coupling agent 10 10 10 10 10 natural oil 5 5 5 5 5 resin 20 23 15 20 23 antioxidant 6 6 6 6 6 vulcanizing agent 1.5 1.5 1.5 1.5 1.5 accelerant 2.5 2.5 2.5 2.5 2.5

(Unit: parts by weight)

1) Natural rubber: It is a rubber obtained from nature and its chemical name is polyisoprene.

2) First S-SBR: solution polymerization styrene-butadiene rubber (SBR) having a styrene content of 20% by weight, a vinyl content of 30% by weight in butadiene, and a Tg of -68°C

3) Second S-SBR: solution polymerization styrene-butadiene rubber (SBR) having a styrene content of 30 wt%, a vinyl content of 40 wt% in butadiene, and a Tg of -15 °C

4) Third S-SBR: solution polymerization styrene-butadiene rubber (SBR) having a styrene content of 25 wt%, a vinyl content in butadiene of 35 wt%, and a Tg of -42 °C

5) Silica: precipitated silica having a nitrogen adsorption value of 175 m ² /g and a CTAB value of 160 m ^{2 /g}

6) Synthetic oil: The total content of PAHs (PolyCyclic Aromatic Hydocarbons) is 3 wt% or less, the kinematic viscosity is 43 °C (210 °F SUS), the aromatic component in the softener is 10 wt%, the naphthenic component is 40 wt% and paraffin TDAE oil containing 40% by weight

7) Natural oil: a natural oil containing 60 to 90% by weight of unsaturated fatty acids, wherein the weight ratio of linoleic acid to oleic acid in the unsaturated fatty acids is 0.5 to 5

8) Resin: Terpene-based resin with a softening point of 120 °C

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

For the rubber specimens prepared in Comparative Examples and Examples, Mooney viscosity, hardness, 300% modulus, viscoelasticity, etc. were measured according to ASTM related regulations, and the results are shown in Table 2.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Mooney viscosity 80 85 85 80 75 Hardness (Shore A) 70 72 76 74 72 300% modulus 89 92 85 84 81 breaking energy 552 523 598 637 665 Tg(℃) -24 -25 -30 -31 -33 Bubble rate (%) 15 23 9 One 3 0℃ tanδ 0.270 0.253 0.250 0.390 0.312 60℃ tanδ 0.110 0.121 0.105 0.098 0.105

1) Mooney viscosity (ML1+4 (125 ℃)) was measured according to ASTM standard D1646.

2) Hardness was measured according to DIN 53505.

3) 300% modulus and breaking energy were measured according to ISO 37 standard.

4) Viscoelasticity was measured from -60 ℃ to 60 ℃, G', G", tanδ under 10Hz frequency at 0.5% strain using RDS measuring instrument.

In Table 2, ML1+4 is a value indicating the viscosity of the unvulcanized rubber. The lower the numerical value, the better the processability of the unvulcanized rubber. The hardness indicates the steering stability, and the higher the value, the better the steering stability. Breaking energy represents the energy required when rubber breaks. The higher the value, the higher the energy required, so the wear resistance is excellent. The cell ratio represents a measure of extrusion processability, and the lower the value, the better the processability. 0℃ tanδ indicates braking performance on dry or wet road surfaces, and the higher the number, the better the braking performance. In addition, 60℃ tanδ represents the rotational resistance performance, and the lower the value, the better the performance.

[Tire manufacturing and performance evaluation]

Tire treads were made using the rubber compositions of Comparative Examples and Examples, and 215/60R16V standard tires including the prepared tire tread rubber as a semi-finished product were manufactured.

Table 3 below shows the relative ratios of low fuel economy performance according to braking distance, rolling resistance, and abrasion resistance on a wet road surface for the tire manufactured in this way. When the relative ratio value has a change range of 5% or more, the effect on improvement and decrease is large. That is, if it is 95 or less, it is difficult to apply due to insufficient performance, and if it is 105 or more, the performance improvement effect is significant.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 rolling resistance 100 97 102 104 102 Wet road braking performance 100 101 97 99 100 Machining performance 100 95 104 110 107 wear resistance performance 100 96 114 121 116

As described above, by using natural oil and resin at the same time, the compatibility of the rubber composition is improved, and thus the tire rolling resistance and abrasion resistance performance as well as the braking performance on a wet road surface are excellent.

Although 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 by those skilled in the art using the basic concept of the present invention as defined in the following claims are also provided. is within the scope of the

Claims (8)

100 parts by weight of a raw rubber containing solution-polymerized styrene-butadiene rubber (S-SBR);
2 to 15 parts by weight of natural oil;
15 to 30 parts by weight of resin;
Silica 80 to 110 parts by weight; and
2 to 10 parts by weight of carbon black,
The raw material rubber,
The styrene content is 10 to 30 wt%, the vinyl content in butadiene is 10 to 40 wt%, the glass transition temperature (Tg) is -70 to -50 °C, and the weight average molecular weight is 300,000 to 1,000,000 g/mol, molecular weight 35 to 60 parts by weight of the first solution-polymerized styrene-butadiene rubber (S-SBR) having a distribution of 1.5 to 2.0;
The styrene content is 20 to 40 wt%, the vinyl content in butadiene is 25 to 45 wt%, the glass transition temperature (Tg) is -30 to -10 °C, and the weight average molecular weight is 1,000,000 to 1,500,000 g/mol, molecular weight 10 to 30 parts by weight of the second solution polymerization styrene-butadiene rubber (S-SBR) having a distribution of 2.0 to 2.5; and
The styrene content is 10 to 30 wt%, the vinyl content in the butadiene is 30 to 55 wt%, the glass transition temperature (Tg) is -50 to -25 °C, and the weight average molecular weight is 200,000 to 700,000 g/mol, molecular weight The rubber composition for a tire tread comprising 20 to 45 parts by weight of the third solution-polymerized styrene-butadiene rubber (S-SBR) having a distribution of 1.5 to 2.5. delete According to claim 1,
The raw material rubber,
2 to 10 parts by weight of natural rubber; and
The rubber composition for a tire tread, comprising 90 to 98 parts by weight of the solution-polymerized styrene-butadiene rubber (S-SBR). According to claim 1,
The natural oil contains 60 to 90% by weight of unsaturated fatty acids,
The rubber composition for a tire tread, wherein the weight ratio of oleic acid to linoleic acid in the unsaturated fatty acid is 0.5 to 5. 5. The method of claim 4,
The rubber composition for a tire tread, wherein the natural oil is at least one selected from the group consisting of sunflower oil, soybean oil, canola oil and grape seed oil. According to claim 1,
The rubber composition for tire tread, characterized in that the resin has a softening point of 20 to 160° C. and a weight average molecular weight of 40 to 2,000 g/mol. According to claim 1,
The silica has a nitrogen adsorption amount of 160 to 180 m ² /g, a CTAB value of 150 to 170 m ² /g, and a DBP oil absorption amount of 180 to 200 cc/100g. A tire manufactured using the rubber composition for a tire tread according to any one of claims 1 and 3 to 7.