KR101376789B1 - 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, wherein the styrene content is 35 to 45% by weight, the vinyl group content is 20 to 30% by weight butadiene, and the glass transition temperature is -30. 30 to 50 parts by weight of the first solution-polymerized styrene-butadiene rubber at -40 ° C, styrene content of 5 to 15% by weight, vinyl group content of butadiene to 35 to 45% by weight, and glass transition temperature of -60 10 to 30 parts by weight of the second solution-polymerized styrene-butadiene rubber having a temperature of from -70 ° C, and 30 to 50 parts by weight of neodymium butadiene rubber, and 80 to 110 parts by weight of silica.
The rubber composition for tire treads improves braking performance on ice roads, and has excellent braking performance on dry roads and wet roads, and has low rotational resistance and thus can be applied for four seasons.

Description

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

The present invention relates to a rubber composition for tire treads and a tire manufactured using the same, and more particularly, to a rubber tread rubber composition applicable to four seasons with improved braking property on wet roads and ice roads, and manufactured using the same. It's about one tire.

Recently, as global warming accelerates, annual snowfall decreases rapidly and snow falls to form icy roads, but snow melts to form wet conditions such as slush or rain.

Since the properties of the rubber composition required for braking performance on dry or wet surfaces and on ice and snow surfaces are incompatible with each other, the performance of one of them is inevitably disadvantageous. In other words, in winter, many people replace with winter tires with excellent braking performance on the snowy road surface, but the braking performance becomes very disadvantageous when it is not snowing or when the snow melts and wet the road surface, which increases the demand for consumers. It is becoming a trend. Particularly, since this is a problem directly related to the stability of the automobile, it is a major concern of the tire manufacturer, and research and development are actively carried out to solve the problem.

In order to solve this problem, conventionally, styrene-butadiene rubber having a high styrene content in the tread tire rubber composition was used to increase the glass transition temperature of the rubber composition to improve braking performance on dry or wet roads. As the content is increased, the hardness and modulus of the rubber at a low temperature are increased, so that the braking performance on the ice snow road is reduced.

In addition, many methods using silica as a reinforcing agent are used. Silica has excellent reinforcement property compared to carbon black, which has excellent braking property on dry or wet roads, and has a low temperature dependence at low temperature. Since the increase rate is lower than that of carbon black, there is an advantage in terms of braking performance on ice and snow.

However, simply replacing the reinforcing agent from carbon black to silica in the winter tire tread rubber composition does not improve the braking performance on wet roads very effectively. The improvement of braking performance on wet roads of silica tires on winter is limited, and the proper matching of two contradictory performances to meet consumer demand remains a difficult technical challenge.

As a prior art document, Patent Document 1 (KR10-2010-0073857 A) includes styrene-butadiene rubber as a tire for four seasons with improved braking performance. However, the invention according to Patent Document 1 includes natural rubber, and the glass transition temperature of styrene-butadiene is rather high, so that the braking performance is limited to improvement. In particular, the braking performance on wet roads has a slight improvement in application to tires for four seasons.

Patent document 2 (KR10-2011-0073063 A) relates to an improved dispersion by including an alkyl thiosilane-based coupling agent together with a raw material rubber and silica, and to improve braking property according to each composition. However, there is a limit to the application to the tires for the four seasons because of the deterioration of the braking performance on the snow surface.

KR 10-2010-0073857 A KR 10-2011-0073063 A

SUMMARY OF THE INVENTION An object of the present invention is to provide a rubber composition for tire treads that improves braking performance on ice and snow roads, and has excellent braking performance on dry and wet roads and has low rotational resistance and is applicable for all seasons.

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

In order to achieve the above object, the rubber composition for a tire tread according to an embodiment of the present invention has a styrene content of 35 to 45% by weight, a vinyl group content of butadiene 20 to 30% by weight, a glass transition temperature 30 to 50 parts by weight of the first solution-polymerized styrene-butadiene rubber at -30 to -40 ° C, 5 to 15% by weight of styrene, 35 to 45% by weight of vinyl group contained in butadiene, and glass transition temperature 10 to 30 parts by weight of the second solution-polymerized styrene-butadiene rubber at -60 to -70 ° C, and 30 to 50 parts by weight of neodymium butadiene rubber, and 80 to 110 parts by weight of silica.

The neodymium butadiene rubber may have a cis 1,4-butadiene content of 98% by weight or more, a glass transition temperature of -100 to -110 ° C, and a molecular weight distribution of 2.0 to 3.0.

The silica may have a BET surface area of 160 to 180 m ² / g and a DBP oil absorption of 180 to 210 ml / 100 g.

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

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

The rubber composition for tire treads according to an embodiment of the present invention has a styrene content of 35 to 45 wt%, a vinyl group content of butadiene 20 to 30 wt%, and a glass transition temperature of -30 to -40 ° C. 30 to 50 parts by weight of the first solution-polymerized styrene-butadiene rubber, 5 to 15% by weight of styrene, 35 to 45% by weight of vinyl group contained in butadiene, and a glass transition temperature of -60 to -70 ° C. 10 to 30 parts by weight of the second solution-polymerized styrene-butadiene rubber, 100 parts by weight of raw rubber including 30 to 50 parts by weight of neodymium butadiene rubber, and 80 to 110 parts by weight of silica.

In general, the styrene content of styrene-butadiene rubber affects the braking performance on wet roads, and the glass transition temperature affects the braking performance on ice roads. Specifically, the higher the styrene content is, the higher the hysteresis of the rubber, the better the braking performance on the wet road surface. In addition, the lower the glass transition temperature, the lower the hardness of the rubber at low temperature, and the braking performance is improved on the snow surface. However, the higher the styrene-butadiene rubber is, the higher the glass transition temperature is.

When the natural rubber is included in the raw rubber, there is a limit to simultaneously improving braking performance, abrasion resistance, and fuel efficiency. Therefore, the raw material rubber includes the first solution-polymerized styrene-butadiene rubber and the second solution-polymerized styrene-butadiene rubber in a range capable of simultaneously improving braking performance, abrasion resistance and fuel efficiency without using natural rubber.

The first solution polymerized styrene-butadiene rubber has a styrene content of 35 to 45% by weight, a vinyl group content of butadiene is 20 to 30% by weight, and a glass transition temperature of -30 to -40 ° C. Since it is relatively high, braking performance on wet roads can be improved.

In general styrene-butadiene rubber, styrene content has a greater influence on braking performance. However, when styrene-butadiene rubber is high not only in the styrene content but also in the vinyl group content contained in butadiene, fuel efficiency and wear resistance may decrease. Thus, the first solution polymerized styrene-butadiene rubber selectively increases styrene content and reduces vinyl content in butadiene. Thus, when the first solution-polymerized styrene-butadiene rubber is in the above range, it may have excellent braking performance but not lower fuel efficiency and wear resistance.

The first solution polymerized styrene-butadiene rubber is included in 30 to 50 parts by weight based on the raw material rubber. When the first solution-polymerized styrene-butadiene rubber is less than 30 parts by weight, a problem may occur that the braking performance is reduced on a wet road surface, and when it exceeds 50 parts by weight, braking performance and fuel efficiency on an ice and snow road surface may be disadvantageous.

The second solution polymerized styrene-butadiene rubber has a styrene content of 5 to 15% by weight, a vinyl group content of 35 to 45% by weight of butadiene, and a glass transition temperature of -60 to -70 ° C. Is relatively low, it is possible to improve the braking performance on the snow surface.

The second solution-polymerized styrene-butadiene rubber has excellent braking performance on the ice snow road surface when the glass transition temperature is within the above range. In addition, the styrene content and the vinyl group content included in the butadiene is to maintain the glass transition temperature in the above range, when the glass transition temperature is out of the range may increase the braking performance on the ice snow road surface.

The second solution polymerized styrene-butadiene rubber is included in 10 to 30 parts by weight based on the raw material rubber. When the first solution-polymerized styrene-butadiene rubber is less than 10 parts by weight, problems of braking performance and rotational resistance may decrease on ice snow roads, and when it exceeds 30 parts by weight, braking performance and wear performance on wet roads may be reduced. there is a problem.

The raw material rubber includes 30 to 50 parts by weight of neodymium butadiene rubber. When the neodymium butadiene rubber is included in less than 30 parts by weight, there is a problem that the rotational resistance and wear performance is lowered, when exceeding 50 parts by weight there is a problem that the braking performance is reduced.

In addition, the neodymium butadiene rubber may have a cis 1,4-butadiene content of at least 98% by weight, a glass transition temperature of -100 to -110 ° C, and a molecular weight distribution of 2.0 to 3.0. Since the neodymium butadiene rubber has a high cis content and a high linearity, the neodymium butadiene rubber not only shows better wear characteristics when mixed with the first and second solution-polymerized styrene-butadiene rubbers, The reduction can improve the rolling resistance.

Preferably, the neodymium butadiene rubber may be an oil. This is because neodymium butadiene rubber containing the oil has better rotation resistance than when oil is added separately. Specifically, neodymium butadiene rubber may be an oil containing 15 to 40% by weight relative to the entire neodymium butadiene rubber. When the amount of the oil is less than 15% by weight, the amount of additional oil is increased, so there is little improvement effect on the rotational resistance, and when the amount exceeds 40% by weight, the hardness of the oil is low because the amount of the total oil is increased. Loss of tread durability and handling performance.

The tire tread rubber composition includes 80 to 110 parts by weight of silica as a reinforcing filler. If the silica is less than 80 parts by weight, a disadvantage in abrasion performance occurs, and if it exceeds 110 parts by weight, a problem in that the rotational resistance is reduced.

The silica may have a BET surface area of 160 to 180 m ² / g and a DBP oil absorption of 180 to 210 ml / 100 g. When the silica is used, the dispersibility is very good, and the braking performance and the abrasion performance on the wet road surface can be optimally realized.

The rubber composition for a tire tread may further include various additives such as an additional vulcanizing agent, a vulcanization accelerator, a vulcanization accelerator, a coupling agent, an anti-aging agent, and a softening agent. The various additives can be used as long as they are commonly used in the field to which the present invention belongs. The content thereof is not particularly limited as long as it depends on a compounding ratio used in a rubber composition for a tire tread.

As the vulcanizing agent, a sulfur vulcanizing agent can be preferably used. The sulfur vulcanizing agent may be an inorganic vulcanizing agent such as powdered sulfur (S), insoluble sulfur (S), precipitated sulfur (S), or colloid sulfur. As the sulfur vulcanizing agent, a vulcanizing agent which produces elemental sulfur or sulfur, for example, amine disulfide, polymer sulfur and the like 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 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 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 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 0.8 to 4.0 parts by weight based on 100 parts by weight of the raw material rubber in order to maximize productivity and rubber properties by promoting the vulcanization rate.

The vulcanization 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. As the organic vulcanization accelerating auxiliary, there may be selected from the group consisting of stearic acid, zinc stearate, palmitic acid, linoleic acid, oleic acid, lauric acid, dibutyl ammonium oleate, derivatives thereof, Can be used.

In particular, the zinc oxide and the stearic acid may be used together as the vulcanization accelerating assistant. In this case, the zinc oxide is dissolved in the stearic acid to form an effective complex with the vulcanization accelerator, Thereby facilitating the crosslinking reaction of the rubber.

When using the zinc oxide and the stearic acid together may be used in an amount of 1 to 5 parts by weight based on 100 parts by weight of the raw material rubber in order to serve as a suitable vulcanization accelerator. If the content of the zinc oxide and the stearic acid is less than the above range, the vulcanization rate may be slow and the productivity may be deteriorated. If the content exceeds the above range, the scorch phenomenon may occur and the physical properties may be deteriorated.

Examples of the coupling agent include a sulfide-based silane compound, a mercapto-based silane compound, a vinyl-based silane compound, an amino-based silane compound, a glycidoxine clock silane compound, a nitro- based silane compound, a chlorosilicate compound, a methacrylic silane compound, May be used.

The sulfide-based silane compound is preferably selected from the group consisting of bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, bis (4-trimethoxysilylbutyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis Bis (3-trimethoxysilylethyl) trisulfide, bis (4-triethoxysilylethyl) trisulfide, bis (4-trimethoxysilylbutyl) trisulfide, bis (3-triethoxysilylbutyl) disulfide, bis (4-triethoxysilylbutyl) disulfide, bis 3-trimethoxysilylpropyl) disulfide, bis (2-trimethoxy Triethoxysilylbutyl) disulfide, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, 3-triethoxysilylpropyl-N, N-dimethyl 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyltetrasulfide, 2-trimethoxysilylethyl-N, N-dimethylthiocarbamoyltetrasulfide, 3-trimethoxysilyl 3-trimethoxysilylpropylmethacrylate monosulfide, 3-trimethoxysilylpropylmethacrylate monosulfide, and combinations thereof may be used in combination with at least one compound selected from the group consisting of benzothiazolyl tetrasulfide, 3-triethoxysilylpropylbenzothiazole tetrasulfide, 3-trimethoxysilylpropylmethacrylate monosulfide, And the like.

The mercaptosilane compound may be at least one selected from the group consisting of 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, 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 preferably selected from the group consisting of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropyltriethoxysilane, 3- Methoxysilane, and a combination thereof.

The glycidoxime silane compound is preferably selected from the group consisting of? -Glycidoxypropyltriethoxysilane,? -Glycidoxypropyltrimethoxysilane,? -Glycidoxypropylmethyldiethoxysilane,? -Glycidoxypropylmethyldimethoxysilane And a combination 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 Lt; / RTI >

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

The coupling agent may be included in an amount of 1 to 20 parts by weight based on 100 parts by weight of the raw rubber for improving dispersibility of the silica. If the content of the coupling agent is less than 1 part by weight, improvement in dispersibility of silica may be insufficient, resulting in deterioration of rubber workability and lowering of fuel consumption performance. When the amount exceeds 20 parts by weight, interaction between silica and rubber is too strong, May be excellent, but the braking performance may be very poor.

The softening agent is added to the rubber composition in order to impart plasticity to the rubber to facilitate processing or to decrease the hardness of the vulcanized rubber, and means an oil or other material used in rubber compounding or rubber production. The softening agent means an oil contained in a process oil or other rubber composition. 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 higher than 3 wt% together with the increase of the environmental consciousness, treated distillate aromatic extract oil, mild extraction solvate (MES) oil, residual aromatic extract (RAE) oil or heavy naphthenic oil.

Particularly, the oil used as the softening agent preferably has a total content of PAHs components of not more than 3 wt%, a kinematic viscosity of not less than 95 (210 S SUS), an aromatic component of 15 to 25 wt%, a naphthene component Of 27 to 37% by weight and a paraffinic component of 38 to 58% by weight 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.

The softener is preferably used in an amount of 10 to 35 parts by weight based on 100 parts by weight of the raw material rubber, in terms of improving processability of the raw material rubber.

The 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 that the solubility of the antioxidant in addition to the anti-aging action is high, the solubility in the rubber is small, the volatility is small, the solubility should be inactive to the rubber, and the vulcanization should not be inhibited, By weight.

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

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 tire treads according to the present invention has an advantage of improving braking performance on ice roads, braking performance on dry roads and wet roads, and also having low rotational resistance and being applicable to four seasons.

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.

[ Manufacturing example : Preparation of rubber composition]

Rubber compositions for tire treads according to the following Examples and Comparative Examples were prepared using the compositions shown in Table 1 below. The production of the rubber composition was in accordance with the usual production method of the rubber composition.

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Example 1 Example 2 Example 3 Natural rubber 20 20 - - - - - - S-SBR ⁽¹⁾ 40 (55) 40 (55) 40 (55) 40 (55) 40 (55) 40 (55) 40 (55) 40 (55) S-SBR ⁽²⁾ - - 5 35 - 10 20 30 S-SBR ⁽³⁾ - - - - 20 - - - BR 1 ⁽⁴⁾ 40 - - - - - - - BR 2 ⁽⁵⁾ - 40 (55) 55 (75.6) 25 (34.4) 40 (55) 50 (68.8) 40 (55) 30 (41.3) Silica ⁽⁶⁾ 100 100 100 100 100 100 100 100 Coupling Agents ⁽⁷⁾ 15 15 15 15 15 15 15 15 Oil Processed ⁽⁸⁾ 35 23.7 14.4 25.6 20 16.2 20 23.7 Zinc oxide 3 3 3 3 3 3 3 3 Stearic acid One One One One One One One One Antioxidant 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4 Vulcanizing agent 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 accelerant 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Accelerator (DPG) 2 2 2 2 2 2 2 2

(Unit: parts by weight)

(1) S-SBR 1: Styrene content of styrene-butadiene rubber (38% by weight of styrene, butadiene-containing vinyl group content of 24% by weight, glass transition temperature of -30 ~ -40 ℃) Figures in parentheses refer to the content of S-SBR rubber with oil).

(2) S-SBR 2: solution-polymerized styrene-butadiene rubber (SBR), which has a styrene content of 10% by weight, a vinyl group content of 40% by weight of butadiene, and a glass transition temperature of -60 to -70 ° C. Contains 27.3% by weight of TDAE Oil.

(3) S-SBR 3: A solution-polymerized styrene-butadiene rubber (SBR) having a styrene content of 24% by weight, a butadiene-containing vinyl group content of 60% by weight, and a glass transition temperature of -25 to -35 ° C.

 (4) BR 1: Nickel butadiene rubber manufactured by Kumho Petrochemical Co., Ltd. under the brand name KBR01.

(5) BR 2: Neodyne butadiene rubber manufactured by Lanxess, which includes 27.3% by weight of CB29MES and MES Oil (the values in parentheses indicate the content of BR rubber including the oil content).

(6) Silica: Precipitated silica having a BET surface area of 160 to 180 m ² / g and a DBP oil absorption of 180 to 210 ml / 100 g.

(7) Coupling agent: Sulfide type silane made by Degussa, trade name is Si69.

(8) Processed oil: total content of Poly Cyclic Aromatic Hydocarbon (PAHs) is 3% by weight or less, kinematic viscosity of 95 ° C (210 ° F SUS), 25% by weight of aromatic components, 32.5% by weight of naphthenic components, and paraffin. An oil having a system component of 47.5 wt% by the name Vivatec500.

[ Experimental Example : Measurement of physical properties of the prepared 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 Comparative Example 5 Example 1 Example 2 Example 3 Glass transition temperature (캜) -70 -70 -77 -63 -55 -75 -70 -65 Mooney viscosity 50 55 46 62 65 48 54 60 Hardness (ShoreA) 64 64 63 65 65 64 64 64 300% Modulus (Mpa) 8.0 7.9 7.0 8.7 84 7.2 7.8 8.4 -40 ℃ G'dyne / ㎠) 1.6E + 09 1.5E + 08 1.3E + 08 1.8 E + 09 2.2E + 09 1.4E + 08 1.6E + 08 1.7E + 09 0 ℃ tanδ 0.220 0.215 0.203 0.255 0.265 0.225 0.233 0.242 60 ℃ tanδ 0.150 0.145 0.142 0.159 0.165 0.145 0.150 0.154

The glass transition temperature was measured using the DSC method.

Mooney viscosity (ML _{1 + 4} (125 ° C.)) was measured according to ASTM standard D1646.

- Hardness was measured by DIN 53505

- 300% Modulus was measured according to ISO 37 standard.

-Viscoelasticity was measured G ', G ”, tan δ from -60 ℃ to 60 ℃ under 10Hz frequency at 0.5% strain using an RDS meter.

In Table 2, ML _{1 +4} is a value representing the viscosity of the unvulcanized rubber, and the lower the value, the more excellent the workability of the unvulcanized rubber. The hardness indicates the steering stability. The higher the value, the better the steering stability. -40 ℃ G 'shows the braking characteristics on the snowy road surface, the lower the value, the better the braking performance, and 0 ℃ tanδ shows the braking performance on the dry or wet road surface, the higher the value, the better the braking performance. . In addition, 60 ° C tan δ indicates rotational resistance characteristics, and a lower value indicates better performance.

In addition, by manufacturing a tread with the rubber of the comparative examples and examples, and manufactured a tire of the 205 / 55R16 standard comprising the prepared tread rubber as a semi-finished product, braking performance on the dry road surface, wet road surface, ice road surface And the relative ratio to the fuel economy performance was measured, the results are shown in Table 3 below.

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Example 1 Example 2 Example 3 Wet road braking performance 100 98 92 112 115 107 110 114 Ice snow road braking performance 100 102 106 96 93 109 104 102 Fuel efficiency 100 104 108 92 90 108 103 101

Referring to Tables 2 and 3, the styrene content is 38% by weight, the vinyl group content in the butadiene is 24% by weight, the glass transition temperature is -30 to -40 ℃ solution polymerization styrene-butadiene rubber and 40 weight When using 10 to 30 parts by weight of a solution-polymerized styrene-butadiene rubber having a content of 10% by weight of butane and styrene, 40% by weight of vinyl group contained in butadiene, and a glass transition temperature of -60 to -70 ° C. Examples 1 to 3) It can be seen that braking performance is improved both on wet roads and on snowy roads while maintaining processability, adjustment stability, and fuel efficiency.

When 38% by weight of natural rubber and styrene, 24% by weight of vinyl group contained in butadiene, and a solution-polymerized styrene-butadiene rubber having a glass transition temperature of -30 to -40 ° C (Comparative Example 2) There was a problem that the braking performance on the road surface is reduced.

In addition, the styrene content is 38% by weight, butadiene contained 24% by weight vinyl content, 40 parts by weight of a solution-polymerized styrene-butadiene rubber (S-SBR 1) having a glass transition temperature of -30 to -40 ℃ Styrene content of 10% by weight, 40% by weight of vinyl group contained in butadiene, and 5 parts by weight of a solution-polymerized styrene-butadiene rubber (S-SBR 2) having a glass transition temperature of -60 to -70 ° C. (Comparative Example 3) It can be seen that the braking performance is reduced on the wet road surface. In addition, when the S-SBR 1 is 40 parts by weight and the S-SBR 2 is contained in 35 parts by weight (Comparative Example 4), it can be seen that the braking performance is reduced on the snow surface. Therefore, it was confirmed that the second solution-polymerized styrene-butadiene rubber has an optimal effect in the range of 10 to 30 parts by weight.

As the second solution-polymerized styrene-butadiene rubber, a solution-polymerized styrene-butadiene rubber having a styrene content of 24%, a vinyl group content of 60% by weight of butadiene, and a glass transition temperature of -25 to -35 ° C In this case, the braking performance on the wet road surface is greatly improved, but the braking performance and fuel efficiency on the ice snow road are greatly reduced.

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 the invention.

Claims (4)

40 parts by weight of a first solution-polymerized styrene-butadiene rubber having a styrene content of 35 to 45% by weight, a vinyl group content of 20 to 30% by weight, and a glass transition temperature of -30 to -40 ° C,
10 to 30 parts by weight of a second solution-polymerized styrene-butadiene rubber having a styrene content of 5 to 15% by weight, a vinyl group content of 35 to 45% by weight, and a glass transition temperature of -60 to -70 ° C; And
30 to 50 parts by weight of neodymium butadiene rubber
Raw material rubber containing 100 parts by weight, and
80 to 110 parts by weight of silica
And a rubber composition for a tire tread. The method of claim 1,
The neodymium butadiene rubber is a content of the cis 1,4-butadiene 98% by weight or more, the glass transition temperature is -100 to -110 ℃, molecular weight distribution is 2.0 to 3.0 rubber composition for tire treads. The method of claim 1,
The silica has a BET surface area of 160 to 180m ² / g, DBP oil absorption of 180 to 210ml / 100g rubber composition for a tire tread. A tire manufactured using the rubber composition for tire tread according to any one of claims 1 to 3.