KR20200021129A - 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 winter tire manufactured by using the same, wherein the rubber composition comprises: 100 parts by weight of raw material rubber; 50 to 80 parts by weight of silica with a low specific surface area having a specific surface area of CTAB adsorption of 60 to 100 m^2/g; and 2 to 50 parts by weight of a vegetable oil. The present invention can provide a tire with improved braking performance on wet and icy road surfaces.

Description

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

The present invention relates to a rubber composition for tire treads with improved handling and braking performance on wet and ice snow roads, and a tire made using the same.

Handling and braking performance on wet roads and ice snow roads, which are necessary for safety during winter driving, are at the same time difficult to improve. In order to maintain handling and braking performance on snow-covered roads and icy roads, moderate hardness and dynamic modulus of tire tread rubber are important. For this purpose, various plasticizers, such as processing oils, are mainly used in the tread rubber composition of a general winter tire.

However, when the processing oil is used a lot, the performance on the snowy road surface is improved but the performance on the wet road surface tends to be lowered. Therefore, the necessity of research on the method of improving the braking performance on the snowy road surface while minimizing the reduction of braking performance on the wet road surface has emerged.

It is an object of the present invention to provide a rubber tread composition for tire treads that can improve braking performance on wet and snow roads.

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

The present invention provides a rubber composition for tire treads comprising 100 parts by weight of raw material rubber, 50 to 80 parts by weight of low specific surface area silica having a CTAB adsorption specific surface area of 60 to 100 m 2 / g, and 2 to 50 parts by weight of vegetable oil.

The raw material rubber comprises 30 to 80 wt% of natural rubber, 10 to 50 wt% of solution-polymerized styrene butadiene rubber having a glass transition temperature of -80 to -40 ° C, and 10 to 50 wt% of butadiene rubber, based on the total weight of the raw rubber. It may be.

The vegetable oil may be any one selected from the group consisting of soybean oil, modified soybean oil, sunflower oil, modified sunflower oil, canola oil, modified canola oil, rapeseed oil, modified rapeseed oil, and combinations thereof.

The present invention also provides a winter tire manufactured using the rubber tread rubber composition.

The present invention can provide a rubber composition for tire treads that can improve braking performance on wet roads and snow roads.

The present invention can also provide a tire manufactured using the rubber composition for tire treads.

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

The rubber composition for tire treads according to the present invention comprises 100 parts by weight of raw rubber, 50 to 80 parts by weight of low specific surface area silica having a CTAB adsorption specific surface area of 60 to 100 m 2 / g, and 2 to 50 parts by weight of vegetable oil.

In the rubber composition for tread, the raw material rubber may include natural rubber, solution-polymerized styrene butadiene rubber and butadiene rubber having a low glass transition temperature.

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 natural rubber may be included in 30 to 80% by weight based on the total weight of the raw rubber. When the natural rubber is included in less than 30% by weight, the braking performance on the ice and snow road surface may be lowered, and when it exceeds 80% by weight, braking performance on the wet road surface may be reduced.

The solution-polymerized styrene butadiene rubber used at the same time is preferably a glass transition temperature (Tg) of -80 to -40 ℃. When the glass transition temperature of the solution-polymerized styrene butadiene rubber is less than -80 ° C, the braking performance may be reduced on wet road surfaces, and when it exceeds -40 ° C, the braking performance may be reduced on ice snow road surfaces. In the case of using the solution-polymerized styrene butadiene rubber having the above characteristics, it is possible to improve the braking performance on the ice snow road surface by maintaining viscosity even in a low temperature region around -30 ° C.

The solution-polymerized styrene butadiene rubber may be included in 10 to 50% by weight based on the total weight of the raw material rubber, and when the solution is out of the range, both the braking performance and the wear resistance of the wet road surface and the snow surface can be reduced. .

Another raw material rubber used is the butadiene rubber, the butadiene rubber may be included in 10 to 50% by weight based on the total weight of the raw rubber. If the weight of the butadiene rubber is less than 10% by weight may cause a problem that the wear performance is reduced, if more than 50% by weight may cause a problem that the braking performance on the wet road surface is reduced.

The rubber composition for tire treads according to the present invention is characterized in that it comprises silica having a low specific surface area as a reinforcing agent. Silica having a low specific surface area can lower the modulus of the rubber composition in the low temperature region, thereby improving the braking performance on the ice snow road surface of the tire. The silica may specifically be CTAB (Cetyltrimethyl ammonium bromide) adsorption specific surface area of 60 to 100 m 2 / g. If the CTAB adsorption specific surface area is less than 60 m 2 / g may cause a problem in wear performance, if the CTAB adsorption specific surface area exceeds 100 m 2 / g may cause a problem in the braking performance on the ice road surface because the hardness of the rubber composition is raised.

The tire tread rubber composition may include 50 to 80 parts by weight of silica having a CTAB specific surface area of 60 to 100 m 2 / g based on 100 parts by weight of raw rubber.

A coupling agent may be additionally included to improve 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 may be used, and sulfide silane compounds may be preferably used.

Since the low specific surface area silica according to the present invention has a lower specific surface area than general silica, there may be a possibility that the surface of the silica lacks a hydrophilic group, which may cause a decrease in braking performance on wet road surfaces. Accordingly, in the present invention, the silane may be minimized in a range that does not degrade the silica dispersion to maximize the braking performance on the wet road surface by maintaining the hydrophilic group as much as possible.

The sulfide silane compound may include 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.

The coupling agent may be included in an amount of 1 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 1 part by weight, the improvement of dispersibility of silica may be insufficient, resulting in deterioration of workability of rubber or low fuel consumption performance. May be good but the braking performance may be very poor.

The rubber composition for tire treads is expected to improve the braking performance on a snowy road surface by including silica of a low specific surface area, but may have a problem that the braking performance on a wet road surface does not improve or decrease at the same time. In order to solve this problem, the rubber composition for tire treads according to the present invention is characterized by including vegetable oil.

The vegetable oil may be any one selected from the group consisting of soybean oil, modified soybean oil, sunflower oil, modified sunflower oil, canola oil, modified canola oil, rapeseed oil, modified rapeseed oil, and combinations thereof. The tire tread rubber composition may maximize the handling and braking performance on the snow surface by minimizing the braking performance on the wet road surface by using a combination of the low specific surface area silica and vegetable oil.

The vegetable oil is preferably used in 2 to 50 parts by weight based on 100 parts by weight of the raw material rubber. When the vegetable oil is included in less than 2 parts by weight of the rubber composition may increase the hardness of the ice composition on the snow surface, and if it exceeds 50 parts by weight, the hardness of the rubber composition is reduced to the steering performance and dry road surface May cause problems in braking performance.

The vegetable oil may be one or more materials selected from soybean, sunflower, canola, rapeseed and the like to extract the oil components using a compression method or a solvent extraction method.

First, the compression method may be prepared by a washing step, a drying step, a milking step, a aging step, and a precipitation step. The drying step may be to dry for 2 to 3 hours in a suction-dry air drying method with a mild heat of 50 to 70 ℃ after washing the selected material. The milking step may be to extract the oil between 80 to 90 ° C. with a conventional presser or Xperer machine. In the aging and precipitation step, the oil extracted through the milking process may be aged at room temperature for 7 to 10 days, and at the same time, the foreign matter may be precipitated to remove the precipitate to separate only the clear oil. Next, the solvent extraction method may be to use an organic solvent such as hexane, alcohol, acetone, benzene, chloromethane, ether. Soybean may be immersed in the organic solvent to extract the oil component and to separate only the oil.

The tire tread rubber composition may optionally further include various additives such as additional adhesives, vulcanizing agents, vulcanization accelerators and anti-aging agents. 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.

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

As the pressure-sensitive adhesive, natural resin-based pressure-sensitive adhesives such as rosin-based resins or terpene-based resins, and synthetic resin-based pressure-sensitive adhesives such as petroleum resins, coal tar, or alkyl phenol-based resins may be used.

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

The petroleum resin is aliphatic resin, acid-modified aliphatic resin, alicyclic resin, hydrogenated alicyclic resin, aromatic (C9) resin, hydrogenated aromatic resin, C5-C9 copolymer resin, styrene resin, styrene copolymer resin and It may be any one selected from the group consisting of a combination of these.

The coal tar may be a coumarone-indene resin.

The alkyl phenol resin may be p-tert-alkyl phenol formaldehyde resin, the p-tert-alkyl phenol formaldehyde resin may be p-tert-butyl-phenol formaldehyde resin, p-tert-octyl-phenol formaldehyde and It may be any one selected from the group consisting of a combination of these.

The pressure-sensitive adhesive may be included in 0.5 to 10 parts by weight based on 100 parts by weight of the raw material rubber. When the content 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 adhesive performance is lowered, and when it exceeds 10 parts by weight, the rubber properties may be lowered, which is not preferable.

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 for producing elemental sulfur or sulfur, for example, amine disulfide, polymer sulfur, and 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 1.5 to 2.5 parts by weight based on 100 parts by weight of the raw material rubber, in that the raw material rubber is less sensitive to heat and chemically stable.

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

The vulcanization accelerators include sulfenamides, thiazoles, thiurams, thioureas, guanidines, dithiocarbamic acids, aldehydes-amines, aldehydes-ammonias, imidazolines, xanthates and the like. Any one selected from the group consisting of a combination can be used.

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

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

Examples of the thiuram 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.

The thiourea-based vulcanization accelerator, for example, thiacarbamide, diethylthiourea, dibutylthiourea, trimethylthiourea, diorthotolylthiourea, and any one selected from the group consisting of a combination thereof Compounds can be used.

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

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

Examples of the aldehyde-amine-based or aldehyde-ammonia-based vulcanization accelerators include 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 2.5 parts by weight based on 100 parts by weight of the raw material rubber in order to maximize productivity and rubber properties by promoting the vulcanization rate.

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

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

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 material rubber, respectively, to serve as a suitable vulcanization accelerator. When the content of zinc oxide and the stearic acid is less than the above range, the vulcanization rate may be low, and productivity may be lowered. When the zinc oxide and the stearic acid are below the above range, a scorch phenomenon may occur and the physical properties may be reduced.

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 amine-based, phenol-based, quinoline-based, imidazole-based, carbamic acid metal salts, waxes, and combinations thereof may be appropriately selected.

Examples of the amine antioxidant include N-phenyl-N '-(1,3-dimethyl) -p-phenylenediamine, N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, N, N'-diphenyl-p-phenylenediamine, N, N'-diaryl-p-phenylenediamine, N-phenyl-N ' Any one selected from the group consisting of -cyclohexyl p-phenylenediamine, N-phenyl-N'-octyl-p-phenylenediamine, and combinations thereof can be used. Examples of the phenolic anti-aging agent include phenolic 2,2'-methylene-bis (4-methyl-6-tert-butylphenol), 2,2'-isobutylidene-bis (4,6-dimethylphenol) and 2 Any one selected from the group consisting of, 6-di-t-butyl-p-cresol and combinations thereof can be used. As the quinoline-based antioxidant, 2,2,4-trimethyl-1,2-dihydroquinoline and its derivatives may be used, and specifically 6-ethoxy-2,2,4-trimethyl-1,2-di Consisting of hydroquinoline, 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. Wax hydrocarbons may be preferably used as the wax.

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 prepared in a suitable mixer using a second step (called a "production" step) of mechanical treatment at a low temperature of less than 110 ° C., for example 40-100 ° 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. The 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 used in the manufacture of tires in the related art, and thus detailed description thereof will be omitted.

The tire may be a passenger car tire, a racing tire, an airplane tire, an agricultural machine tire, an off-the-road tire, a truck tire or a bus tire. The tire may also be used as a radial tire or a bias tire.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

Preparation Example 1 Preparation of Tread Rubber Composition

A rubber composition for tire treads according to the following examples and comparative examples was prepared using the composition shown in Table 1 below. The preparation of the rubber composition was in accordance with a conventional method for producing a rubber composition.

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example 1 Example 2 Raw material rubber 100 100 100 100 100 100 Silica 65 - 65 - - - Low specific surface area silica - 65 - 65 65 65 Processing oil 30 30 - 30 - - vegetable oil - - 30 - 30 20 Silane 5.2 5.2 5.2 2.6 2.6 2.6

(Unit: parts by weight)

Raw material rubber: mixed rubber of 60% by weight of natural rubber, 20% by weight of solution-polymerized styrene butadiene rubber and 20% by weight of butadiene rubber having a Tg of -60 ° C.

Silica: Silica with CTAB 165 m 2 / g

Low specific surface area silica: Silica with CTAB 90 m 2 / g

Processed oil: TDAE (Treated Distillate Aromatic Extract) Oil

Vegetable oil: Soybean Oil

Experimental Example 1: Measurement of physical properties of the manufactured rubber composition

The physical properties of the rubber specimens prepared in Examples and Comparative Examples were measured, and the results are shown in Table 2 below.

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4   Example 1 Example 2 Mooney viscosity
(100 ℃) 55 45 51 44 41 45 Tmax (150 ° C) 25.4 23.1  21.5 24.2 19.3 24.2  t90 (150 ℃) 4.3 4.2 4.1 4.9 5.1 5.5 ShoreA 60 58 58 57 53 57 300% modulus (kgf / ㎠) 90 87 88 84 82 86 0 ℃ tanδ 0.138 0.132 0.125 0.137 0.131 0.139 -30 ℃ G '(10E + 6) 8.5 7.2 6.9 7.5 6.2 6.7 60 ℃ tanδ 0.08 0.06 0.06 0.07 0.05 0.05

Mooney viscosity (ML1 + 4 (100 ° C.)) was measured according to ASTM standard D1646. Mooney viscosity is a value indicating the viscosity of the unvulcanized rubber, the lower the value, the more excellent workability of the unvulcanized rubber.

-Tmax (150 ° C), t90 (150 ° C): Measured by MDR measuring instrument, Tmax is the maximum time until it rises 5 points from the minimum value, and t90 is the time it takes until it rises 90 points.

Hardness (ShoreA): measured according to DIN 53505. Hardness represents adjustment stability, and the higher the value, the better the adjustment stability.

-300% modulus (kgf / cm 2): measured according to ISO 37 standard.

-0 ℃ tan δ, -30 ℃ G '(10E + 6), 60 ℃ tan δ: was measured using a Dynamic Mechanical Analyzer (DMA, DMTA) to measure the viscoelastic properties of the prepared specimen. 0 ° C tanδ represents the braking characteristics on dry or wet roads. The higher the value, the better the braking performance. -30 ℃ G 'shows braking characteristics on ice and snow surface. The lower the value, the better. In addition, 60 ° C tan δ indicates rotational resistance characteristics, and a lower value indicates better performance.

From the results of Table 2, the -30 ℃ G 'performance of Comparative Examples 2, 4 containing low specific surface area silica was improved, from which the braking performance on the ice snow road surface is expected to be improved.

On the other hand, Comparative Example 3, which does not contain low specific surface area silica but contains vegetable oil, also shows that the -30 ° C G 'performance is slightly improved, and the 0 ° C tanδ performance is deteriorated. This improvement and reduction in wet road braking performance were expected.

However, in Examples 1 and 2 including both low specific surface area silica and vegetable oil, both 30 ° C. G 'and 0 ° C. tanδ performances were improved, thereby improving not only the braking performance on the snowy road surface but also the braking performance on the wet road surface. It is expected to be.

Experimental Example 2: Evaluation of Braking Performance of Tire Using Tread Rubber Composition

A tire of the 205 / 55R16 standard made of the tread made of the rubber of the comparative examples and examples and including the tread rubber as a semi-finished product was produced. The hardness is shown in Table 3. Relative ratio values have a significant effect on improvement and reduction when the variation rate is 5% or more, i.e., a value of 95 or less is difficult to apply due to lack of performance, and a value of 105 or more is a significant level of performance improvement.

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example 1 Example 2 Wet Road Braking Performance 100 97 95 99 96 101 Braking performance 100 103 105 102 107 105

Referring to Table 3, in Examples 1 and 2 simultaneously comprising low specific surface area silica and vegetable oil, it was confirmed that the braking performance of the ice-snow road surface showed a value of 105 or more, particularly in Example 2 including 20 parts by weight of vegetable oil. It was confirmed that the braking performance of the wet road surface and the braking performance of the snow road surface improved to a similar level.

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 (4)

100 parts by weight of raw rubber,
50 to 80 parts by weight of low specific surface area silica having a CTAB adsorption specific surface area of 60 to 100 m 2 / g, and
2 to 50 parts by weight of vegetable oil
Rubber composition for tire treads comprising a. The method of claim 1,
The raw material rubber comprises 30 to 80 wt% of natural rubber, 10 to 50 wt% of solution-polymerized styrene butadiene rubber having a glass transition temperature of -80 to -40 ° C, and 10 to 50 wt% of butadiene rubber, based on the total weight of the raw rubber. A rubber composition for tire tread. The method of claim 1,
The vegetable oil is any one selected from the group consisting of soybean oil, modified soybean oil, sunflower oil, modified sunflower oil, canola oil, modified canola oil, rapeseed oil, modified rapeseed oil and combinations thereof. A winter tire manufactured using the rubber composition for tire tread according to any one of claims 1 to 3.