KR101905118B1 - Rubber composition for tire tread with improved abrasion resistance - Google Patents

Abstract

The present invention relates to a rubber composition for tire tread with improved abrasion resistance. The rubber composition for the tire tread can maximize the reactivity and dispersibility with silica by including both end-modified solution-polymerized styrene-butadiene rubber. As a result, the wear resistance of a tire is improved, and braking properties and fuel consumption properties can be improved.

Description

TECHNICAL FIELD [0001] The present invention relates to a rubber composition for a tire tread having improved abrasion resistance,

To a rubber composition for a tire tread having improved abrasion resistance. More specifically, the present invention relates to a rubber composition for a tire tread capable of improving abrasion resistance, braking performance and fuel consumption performance of a tire.

BACKGROUND OF THE INVENTION [0002] Today, the demand level of tires is very diverse, and there is a demand for a technology that can appropriately meet all the characteristics of steering stability, noise, straightness, rotation resistance, abrasion resistance, braking force,

In particular, researches on tires employing silica filler as a technique for achieving both braking performance and fuel efficiency have been actively conducted. The biggest technical challenge in silica tires is the mixing of hydrophilic silica with a hydrophobic rubber material.

The degree of mixing of the silica and the rubber material leads to the dispersibility of the silica, and optimal performance can be achieved when the silica is well dispersed in the rubber matrix. Therefore, in order to improve the dispersibility of the silica and the rubber material, a coupling agent that improves the bonding force between the two materials is used, and silane is generally used as the coupling agent. However, in the case of using the silane, if the silane reaction does not occur properly, the dispersion of the silica is deteriorated and the characteristics of the rubber composition are not properly developed.

Accordingly, there is a need to develop a rubber composition for a tire tread which can improve both the abrasion resistance, the braking performance and the fuel consumption performance by improving the dispersibility with the rubber material and silica.

10-2015-0001281, Nexen Tire Co., Ltd., January 06, 2015

And a rubber composition for a tire tread which can improve both abrasion resistance, braking performance and fuel consumption performance on the road surface of a tire.

According to one aspect, 100 parts by weight of a starting rubber comprising 50 to 95 parts by weight of a solution-polymerized styrene-butadiene rubber and 5 to 50 parts by weight of a butadiene rubber; And 60 to 100 parts by weight of silica relative to 100 parts by weight of the raw material rubber.

According to another aspect, there is provided a tire made from the rubber composition for a tire tread.

The rubber composition for a tire tread contains a solution-polymerized styrene-butadiene rubber having both ends modified, thereby maximizing the reactivity and dispersibility with silica. As a result, the wear resistance of the tire is improved, and the braking characteristic and the fuel consumption characteristic can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic representation of a tire according to an embodiment of the invention.
Figure 2 is a schematic representation of a two-end denatured solution polymerized styrene-butadiene rubber in accordance with one embodiment of the present invention.

Hereinafter, a rubber composition for a tire tread according to an embodiment of the present invention and a tire made therefrom will be described in detail. The following is presented as an example, and the present invention is not limited thereto, and the present invention is only defined by the scope of the following claims.

[tire For tread  Rubber composition]

The rubber composition for a tire tread according to one embodiment comprises 100 parts by weight of a raw rubber comprising 50 to 95 parts by weight of a solution-polymerized styrene-butadiene rubber modified at both ends and 5 to 50 parts by weight of a butadiene rubber; And 60 to 100 parts by weight of silica relative to 100 parts by weight of the raw material rubber.

The rubber composition for a tire tread is characterized by maximizing the reduced reactivity and dispersibility with silica due to the application of the conventional single-ended transformer by including the solution-polymerized styrene-butadiene rubber at both ends in the raw rubber.

The raw material rubber serves as a base of a rubber composition for a tire tread and serves to impart basic performance, for example, braking force, steering stability, and the like to the tire.

According to one embodiment, the raw rubber comprises solution-polymerized styrene butadiene rubber, wherein the solution-polymerized styrene-butadiene rubber is both end-modified.

By modifying both ends of the solution-polymerized styrene-butadiene rubber with a functional group, the dispersibility of the silica is maximized through the reaction between the functional group and the silica, thereby lowering the heat generation and fatigue performance and improving the abrasion resistance of the tire.

As the functional group, any functional group capable of improving the dispersibility of silica by physically and chemically bonding to a strong hydrophilic group present on the surface of the silica, that is, a silanol group (-SiOH) can be used. Examples of the functional group include, but are not limited to, at least one selected from the group consisting of a carboxyl group, a hydroxyl group, an amine group, an alkoxyl group, a silanol group, a sulfonyl group, tin (Sn) .

Both ends of the solution-polymerized styrene-butadiene rubber may be denatured to the same or different functional groups. For example, both ends of the solution-polymerized styrene-butadiene rubber may be modified with the same carboxyl group. For example, one end of the solution-polymerized styrene-butadiene rubber may be modified with a carboxyl group and the other end may be modified with a hydroxyl group.

The content of the functional groups may be 10 to 30 parts by weight based on 100 parts by weight of the solution-polymerized styrene-butadiene rubber. For example, the content of the functional groups may be 15 to 25 parts by weight based on 100 parts by weight of the solution-polymerized styrene-butadiene rubber. When the content of the functional group is less than 10 parts by weight, the dispersibility with silica is low, and when it exceeds 30 parts by weight, excessive mixing may deteriorate the mixing processability.

The two-end modified solution-polymerized styrene-butadiene rubber may be contained in an amount of 50 to 95 parts by weight based on 100 parts by weight of the raw rubber. For example, 60 to 85 parts by weight based on 100 parts by weight of the starting rubber. For example, 70 to 80 parts by weight based on 100 parts by weight of the raw rubber. When the content of the styrene-butadiene rubber is less than 50 parts by weight or more than 95 parts by weight, the abrasion resistance and fuel consumption performance may be deteriorated.

In addition, the solution-polymerized styrene-butadiene rubber modified at both ends by the raw material rubber may be used alone, or may be mixed with natural rubber or synthetic rubber in some cases.

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 and the like are not limited. The modified natural rubber may be one obtained by modifying or refining the general natural rubber, and may include an epoxidized natural rubber (ENR), a deproteinized natural rubber (DPNR), and a hydrogenated natural rubber.

The synthetic rubber may include at least one selected from among butadiene rubber (BR), isoprene-containing styrene butadiene rubber, nitrile-containing styrene butadiene rubber, neoprene rubber, chlorobutyl rubber and bromobutyl rubber.

According to one embodiment, the raw material rubber may further include a butadiene rubber. For example, 5 to 50 parts by weight of butadiene rubber may be added to 100 parts by weight of the raw rubber. For example, 20 to 30 parts by weight of butadiene rubber may be included relative to 100 parts by weight of the raw rubber. When the content of the butadiene rubber is less than 5 parts by weight or exceeds 50 parts by weight, abrasion resistance, braking performance, and fuel consumption performance may be deteriorated.

The solution-polymerized styrene-butadiene rubber may have a weight average molecular weight of 500,000 to 1,000,000 g / mol and a molecular weight distribution (MWD) of 1.5 to 1.9. For example, the solution-polymerized styrene-butadiene rubber may have a weight average molecular weight of 700,000 to 900,000 g / mol. When the weight average molecular weight of the solution-polymerized styrene-butadiene rubber falls within the above range, there is an excellent effect in wear resistance, braking performance and fuel consumption performance.

Generally, solution-polymerized styrene-butadiene rubbers can be prepared by a continuous process and a batch process.

According to one embodiment, the solution-polymerized styrene-butadiene rubber may be one that is continuously polymerized. The solution polymerized styrene-butadiene rubber produced by the continuous process is somewhat less processable due to the long molecular chains than the solution polymerized styrene-butadiene rubber prepared by the batch process, but is advantageous in abrasion resistance due to its high molecular weight.

The solution-polymerized styrene-butadiene rubber may contain styrene in an amount of 10 to 30% by weight based on 100% by weight of the styrene-butadiene rubber. When the solution-polymerized styrene-butadiene rubber has a styrene content within the above range, hysteresis of the rubber can be reduced to improve the fuel-efficiency performance.

In addition, the solution-polymerized styrene-butadiene rubber may have a glass transition temperature of -45 to -25 占 폚. When the glass transition temperature is in the above range, the flowability of the rubber at room temperature is increased, and the hysteresis loss is reduced, so that the cut and chip performance, wear performance and fuel consumption performance can be improved.

The solution-polymerized styrene-butadiene rubber may further comprise 20.0 to 50.0 parts by weight of treated distillate aromatic extract (TDAE) oil per 100 parts by weight of solid rubber component. When the solution-polymerized styrene-butadiene rubber further contains 20.0 to 50.0 parts by weight of TDAE oil per 100 parts by weight of the rubber solid content, the flexibility of the styrene-butadiene rubber degraded by the influence of styrene can be expected to increase, The process improvement can be expected by reducing the generation of pores generated from the reaction.

The rubber composition for a tire tread may further include a filler to improve the reinforcing property of the tire. According to one embodiment, the filler may further comprise carbon black in addition to the silica.

According to one embodiment, the content of the filler may be 10 to 150 parts by weight based on 100 parts by weight of the raw rubber. According to one embodiment, the content of the filler may be 50 to 80 parts by weight based on 100 parts by weight of the raw material rubber. If the content of the filler is less than 10 parts by weight based on 100 parts by weight of the raw material rubber, the improvement of the strength of the rubber may be insufficient and the braking performance of the tire may be decreased. When the content of the filler is less than 100 parts by weight The abrasion resistance of the tire may be deteriorated.

According to one embodiment, the rubber composition for a tire tread may comprise silica as a filler.

Silica generally exhibits polarity due to strong hydrophilic functional groups present on its surface, i.e., silanol groups (-SiOH), and due to silica agglomerates which are strongly bonded to each other by hydrogen bonding or dipole bonding, The blendability with the raw material rubber and the processability are low, and as a result, the rotation resistance property and the wear resistance of the tire are lowered. However, in the rubber composition for a tire tread of the present invention, both ends of the solution-polymerized styrene-butadiene rubber are modified by a hydrophilic group to physically and chemically bond to a strong hydrophilic group present on the surface of the silica, i.e., a silanol group (-SiOH) Can be improved. As a result, wear resistance, braking performance, and fuel consumption performance of the tire can be improved.

The silica may be included in an amount of 60 to 100 parts by weight based on 100 parts by weight of the raw rubber. For example, the silica may be included in an amount of 70 to 100 parts by weight based on 100 parts by weight of the raw rubber. For example, the silica may be included in an amount of 80 to 100 parts by weight based on 100 parts by weight of the raw rubber. For example, the silica may be contained in an amount of 90 to 100 parts by weight based on 100 parts by weight of the raw rubber. When the content of silacar is within the above range, braking and abrasion resistance can be improved. If the content of silica is less than 60 parts by weight or exceeds 100 parts by weight, the processability may be significantly lowered.

The silica may have a nitrogen adsorption specific surface area of 210 to 230 m 2 / g and a cetyltrimethyl ammonium bromide (CTAB) adsorption specific surface area of 190 to 210 m 2 / g. For example, the silica may have a nitrogen adsorption specific surface area of 155 to 185 m 2 / g and a cetyltrimethyl ammonium bromide (CTAB) adsorption specific surface area of 150 to 170 m 2 / g. Since the silica used in the rubber composition for tire tread of the present invention has a large specific surface area, it is possible to improve the abrasion resistance and braking performance of the tire.

The silica may be surface treated with a coupling agent, and the coupling agent may be a tetrasulfide-based silane, preferably triethoxysilylpropyltetrasulfide. The coupling agent may be surface-treated using 5 to 20 parts by weight based on 100 parts by weight of silica.

According to one embodiment, the rubber composition for a tire tread may comprise carbon black as a filler.

The carbon black can prevent degradation of abrasion performance according to use of the silica, and can improve the appearance characteristic of the tire tread by increasing coloring degree by black coloring. In addition, the mixing temperature is higher than that in the case of using silica alone, so that the scorch phenomenon and the weakening of the bond between the silica and the silane coupling agent can be prevented.

The rubber composition for tire tread reacts with the silanol groups of the silica to change the surface chemical properties to facilitate the mixing of the silica and the rubber. As a result, the rubber composition for tire tread maintains the low fuel consumption performance and improves the abrasion resistance, And may further include a dispersant to improve the external coloring degree.

According to one embodiment, the dispersant may be a silane coupling agent. For example, the silane coupling agent may be at least one selected from the group consisting of a sulfide-based silane compound, a mercapto-based silane compound, a vinyl-based silane compound, an amino-based silane compound, And mixtures thereof.

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 Trimethoxysilylpropylmethacrylate monosulfide, 3-trimethoxysilylpropylmethacrylate monosulfide, and mixtures thereof, in the presence of at least one compound selected from the group consisting of benzothiazolyl tetrasulfide, 3-triethoxysilylpropylbenzothiazole tetrasulfide, 3-trimethoxysilylpropylmethacrylate monosulfide, Can be selected.

The mercaptosilane compound is preferably selected from the group consisting of 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, Can be selected. The vinyl-based silane compound may be selected from ethoxysilane, vinyltrimethoxysilane, and mixtures 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 mixtures thereof. The glycidoxime silane compound is preferably selected from the group consisting of? -Glycidoxypropyltriethoxysilane,? -Glycidoxypropyltrimethoxysilane,? -Glycidoxypropylmethyldiethoxysilane,? -Glycidoxypropylmethyldimethoxysilane And mixtures thereof. The nitro-based silane compound may be selected from 3-nitropropyltrimethoxysilane, 3-nitropropyltriethoxysilane, and mixtures thereof. The chloro-based silane compound may be selected from 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 2-chloroethyltrimethoxysilane, 2-chloroethyltriethoxysilane, and mixtures thereof . The methacrylic silane compound may be selected from? -Methacryloxypropyltrimethoxysilane,? -Methacryloxypropylmethyldimethoxysilane,? -Methacryloxypropyldimethylmethoxysilane, and mixtures thereof.

According to one embodiment, the content of the dispersant may be 1 to 10 parts by weight based on 100 parts by weight of the filler. According to another embodiment, the content of the dispersant may be 3 to 8 parts by weight based on 100 parts by weight of the filler. If the content of the dispersing agent is less than 1 part by weight based on 100 parts by weight of the filler, the dispersing agent can not effectively bind the raw rubber with the filler, thereby causing a dispersion problem of the rubber composition for tire. When the content is more than 10 parts by weight based on 100 parts by weight of the filler, the dispersant may excessively bind the raw rubber and the filler to increase the toughness of the tire, thereby reducing the elasticity of the tire .

The rubber composition for tire tread may further contain additives insofar as the effects and objects of the present invention are not impaired.

According to one embodiment, the additive may include at least one selected from the group consisting of an antioxidant, a vulcanizing agent, a vulcanizing accelerator and a vulcanizing accelerator.

The vulcanizing agent may include a metal oxide such as a sulfur vulcanizing agent, an organic peroxide, a resin vulcanizing agent, or a magnesium oxide.

The sulfur vulcanizing agent is an inorganic vulcanizing agent such as powder sulfur (S), insoluble sulfur (S), precipitated sulfur (S), colloid sulfur, etc., tetramethylthiuram disulfide (TMTD) An organic vulcanizing agent such as tetraethyltriuram disulfide (TETD), dithiodimorpholine and the like, and a vulcanizing agent for producing elemental sulfur or sulfur such as an amine disulfide, a polymer Sulfur, and the like.

Also, the organic peroxide may be at least one selected from the group consisting of benzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, t-butyl cumyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, 2,5- Di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5- Butyl peroxybenzene peroxide, 3-bis (t-butylperoxypropyl) benzene, di-t-butylperoxy-diisopropylbenzene, t-butylperoxybenzene, -3,3,5-trimethylsiloxane, or n-butyl-4, 4-di-t-butylperoxyvalerate and the like.

The vulcanizing agent may be used in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the raw rubber. When the content of the vulcanizing agent is within the above range, it is possible to make the raw rubber less sensitive to heat and chemically stable as an appropriate vulcanization effect.

The vulcanization accelerator refers to an accelerator that promotes the vulcanization rate or accelerates the retardation in the initial vulcanization step. The vulcanization accelerator may be selected from the group consisting of sulfenamide, thiazole, thiuram, thiourea, guanidine, dithiocarbamate, aldehyde-amine, aldehyde-ammonia, imidazoline, ≪ / RTI >

The sulfenamide-based vulcanization accelerator includes N-cyclohexyl-2-benzothiazyl sulfenamide (CBS), N-tert-butyl-2-benzothiazyl sulfenamide (TBBS), N, N-dicyclohexyl- Benzothiazyl sulfenamide, N-oxydiethylene-2-benzothiazyl sulfenamide, N, N-diisopropyl-2-benzothiazole sulfenamide and mixtures thereof.

The thiol-based vulcanization accelerator may be one or more selected from the group consisting of 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- (2,6-diethyl 4-morpholinothio) benzothiazole, and mixtures thereof.

Examples of the thiuram-based vulcanization accelerator include tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide, tetramethylthiuram monosulfide, dipentamethylthiuram disulfide, dipentamethylthiuram monosulfide, dipentamethylene Diphenylmethyl thiuram tetrasulfide, diphenylmethyl thiuram hexa sulphide, tetramethyl thiuram disulfide, pentamethylenethiuram tetrasulfide, and mixtures thereof.

The thiourea vulcanization accelerator may be selected from thiocarbamides, diethyl thiourea, dibutyl thiourea, trimethyl thiourea, diorthotolyl thiourea, and mixtures thereof.

The guanidine vulcanization accelerator may be selected from N, N-diphenylguanidine (DPG), diorthotolylguanidine, triphenylguanidine, orthotolylbiguanide, diphenylguanidine phthalate, and mixtures thereof.

Examples of the dithiocarbamate-based vulcanization accelerator include zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, dibutyldithi Zinc dicamyldithiocarbamate, zinc dipentyldithiocarbamate, complexing of zinc with piperadinedithiocarbamate and piperidine, zinc hexadecylisopropyldithiocarbamate, octadecylisopropyldithiocarbamate, Zinc dibenzyldithiocarbamate, sodium diethyldithiocarbamate, pentamethylenedithiocarbamate, sodium selenium dimethyldithiocarbamate, diethyldithiocarbamate, sodium diethyldithiocarbamate, diethyldithiocarbamate, Cadmium carbide, and mixtures thereof.

The aldehyde-amine-based or aldehyde-ammonia-based vulcanization accelerator may be selected from acetaldehyde-aniline reactant, butylaldehyde-aniline condensate, hexamethylenetetramine, acetaldehyde-ammonia reactant, and mixtures thereof.

The imidazoline-based vulcanization accelerator may include an imidazoline-based compound such as 2-mercaptoimidazoline, and the xanthate vulcanization accelerator may include a xanthate-based compound such as zinc dibutylxanthogenate have.

The content of the vulcanization accelerator may be 0.1 to 10 parts by weight based on 100 parts by weight of the raw material rubber in order to maximize productivity improvement and rubber property enhancement through vulcanization speed promotion.

The vulcanization accelerating assistant may be selected from the group consisting of inorganic vulcanization accelerators, organic vulcanization accelerators, and mixtures thereof, which are used in combination with the vulcanization accelerators to complete their promoting effects.

The inorganic vulcanization accelerating auxiliary may be selected from zinc oxide (ZnO), zinc carbonate, magnesium oxide (MgO), lead oxide, potassium hydroxide, and mixtures thereof.

The organic vulcanization accelerating auxiliary may be selected from stearic acid, zinc stearate, palmitic acid, linoleic acid, oleic acid, lauric acid, dibutyl ammonium oleate, derivatives thereof, and mixtures thereof.

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 the zinc oxide and stearic acid are used together, the content of the zinc oxide and stearic acid may be 1 to 10 parts by weight based on 100 parts by weight of the raw material rubber so as to serve as a proper vulcanization accelerating auxiliary.

[Method of producing rubber composition for tire]

The rubber composition for a tire tread can be produced by kneading the respective components described above using a known apparatus (for example, an intermeshing type mixer, a kneader, a roll, etc.), and the two- The silica may be dispersed by reacting silica at both terminal functional groups of the rubber.

[tire]

The tire of the present invention is a tire manufactured from the rubber composition of the present invention described above. According to one embodiment, the tire of the present invention may use the rubber composition of the present invention described above for the tire tread portion.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic representation of a tire according to an embodiment of the invention.

1, there is a carcass layer 4 in which a fiber cord is embedded between a pair of right and left bead portions 1, and an end portion of the carcass layer 4 is connected to a bead core 1 5 and the bead filler 6 are folded back and folded outward from the inside of the tire. Further, in the tire tread 3, the belt layer 7 is arranged on the outer side of the carcass layer 4 over the tire 1. Further, in the bead portion 1, a rim cushion 8 is disposed at a portion in contact with the rim.

The tire of the present invention can be manufactured, for example, using a conventionally known method.

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

[ Example ]

≪ Application of Both End Modification and Preparation of Rubber Composition According to Molecular Weight of Solution Polymerized Styrene-Butadiene Rubber >

Example  1 to 4 and Comparative Example  1 and 2

Each component shown in the following Table 1 was put into a Banbury mixer at the ratio shown in the following Table 1 (parts by weight), mixed and vulcanized at 160 캜 for 15 minutes to prepare a rubber composition for a tire. However, after all ingredients were added to the Banbury mixer, the ratio of each component was adjusted so that the fill factor of the intermeshing type mixer having a capacity of 1.65 L was 0.65 to 0.70.

Rubber composition for tire (unit: parts by weight) division Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 Single-ended denaturation S-SBR ⁽¹⁾ 70 - - - - - Both ends
denaturalization S-SBR ⁽²⁾ - 70 - - - - S-SBR ⁽³⁾ - - 80.5 - - - S-SBR ⁽⁴⁾ - - - 84.0 - - S-SBR ⁽⁵⁾ - - - - 96.25 - S-SBR ⁽⁶⁾ - - - - - 96.25 BR ⁽⁷⁾ 30 30 30 30 30 30 Carbon black ⁽⁸⁾ 16 16 16 16 16 16 Silica ⁽⁹⁾ 73 73 73 73 73 73 The silane coupling agent ⁽¹⁰⁾ 5.84 5.84 5.84 5.84 5.84 5.84 Stearic acid 2 2 2 2 2 2 zinc oxide 2 2 2 2 2 2 Antioxidant 2 2 2 2 2 2 Processing aid 1 ⁽¹¹⁾ 3 3 3 3 3 3 Processing aid 2 ⁽¹²⁾ 4 4 4 4 4 4 Oil ⁽¹³⁾ 29.0 29.0 18.5 15.0 2.75 2.75 Vulcanizing agent (sulfur) ⁽¹⁴⁾ 1.3 1.3 1.3 1.3 1.3 1.3 Vulcanization accelerator 1 ⁽¹⁵⁾ One One One One One One Vulcanization accelerator 2 ⁽¹⁶⁾ 2 2 2 2 2 2

(1) S-SBR having a weight average molecular weight of 4.6 x 10 ⁵ g / mol, a molecular weight distribution of 1.3, a styrene content of 20%, a vinyl content of 56% and a glass transition temperature of -35 캜, product of styrene-butadiene rubber (HPR350 ^®, JSR Inc.)

(2) S-SBR: A styrene-butadiene copolymer having a weight average molecular weight of 5.5 x 10 ⁵ g / mol, a molecular weight distribution of 1.6, a styrene content of 20%, a vinyl content of 56% and a glass transition temperature of- Butadiene rubber (SOL 5251H ^® , KKPC Inc.)

(3) S-SBR having a weight average molecular weight of 5.5 x 10 ⁵ g / mol, a molecular weight distribution of 1.5, a styrene content of 20%, a vinyl content of 56% and a glass transition temperature of -35 캜, Modified styrene-butadiene rubber (MF1847E-G, LG Chem) containing 15.0 parts by weight

(4) S-SBR having a weight average molecular weight of 7.3 x 10 ⁵ g / mol, a molecular weight distribution of 1.8, a styrene content of 20%, a vinyl content of 56% and a glass transition temperature of -35 캜, Modified styrene-butadiene rubber (MF1847E-H, LG Chem) containing 20.0 parts by weight

(5) S-SBR having a weight average molecular weight of 8.9 x 10 ⁵ g / mol, a molecular weight distribution of 1.9, a styrene content of 20%, a vinyl content of 56% and a glass transition temperature of -35 캜, End modified styrene-butadiene rubber (MF1847E-I, LG Chem) containing 37.5 parts by weight of a styrene-

(6) S-SBR having a weight average molecular weight of 9.5 x 10 ⁵ g / mol, a molecular weight distribution of 1.8, a styrene content of 20%, a vinyl content of 56% and a glass transition temperature of -35 캜, End modified styrene-butadiene rubber (MF1847E-J, LG Chem) containing 37.5 parts by weight of a styrene-

(7) BR: Butadiene rubber (KBR01 ^® , KKPC Inc.)

(8) Carbon black: Carbon black particles (iodine adsorption value 142 mg / g, oil adsorption specific surface area (OAN) 127 cc / 100 g, pour density 320 g / dm ³ )

(9) Silica: Silica (7000 HD-165GRN, EVONIK UNITED SILICA (SIAM)) having a nitrogen adsorption specific surface area of 170 m ² / g and a CTAB adsorption specific surface area of 160 m ² /

(10) Silane coupling agent: tetrasulfide compound (Si69 ^® , Evonik) having a sulfur content of 23% by weight and a molecular weight of 535 g / mol,

11, processing (1): each porous improved zinc fatty acid soap ^(® HT276, Struktol Co.)

(12) Processing aid 2: Fatty acid zincation / potassium soap (EF-44, Dong-Eun Chemical) for improving processability and dispersibility

(13) Oil: Residual Aromatic Extract (Korea Shell Oil Co., Ltd.)

(14) Vulcanizing agent: Ground sulfur

(15) Vulcanization accelerator 1: N-cyclohexyl-2-benzothiazoylsulfanamide (available from SHANDONG SHANXIAN CHEMICALS)

(16) Vulcanization accelerator 2: diphenylguanidine (manufactured by SHANDONG SHANXIAN CHEMICALS)

≪ Application of both ends modification and production of rubber composition according to silica content >

Example  5 to 7 and Comparative Example  3 and 4

Each component shown in the following Table 2 was put into a Banbury mixer at a ratio shown in the following Table 2 (parts by weight), mixed and vulcanized at 160 캜 for 15 minutes to prepare a rubber composition for a tire. However, after all ingredients were added to the Banbury mixer, the ratio of each component was adjusted so that the fill factor of the intermeshing type mixer having a capacity of 1.65 L was 0.65 to 0.70.

division Comparative Example 3 Comparative Example 4 Example 5 Example 6 Example 7 Single-ended denaturation S-SBR ⁽¹⁾ 70 - - - - Both ends
denaturalization S-SBR ⁽²⁾ - 70 - - - S-SBR ⁽³⁾ - - 96.25 96.25 96.25 BR ⁽⁴⁾ 30 30 30 30 30 Carbon black ⁽⁵⁾ 5 5 5 5 5 Silica ⁽⁶⁾ 80 80 80 90 100 Silane coupling agent ⁽⁷⁾ 8 8 8 9 10 Stearic acid 2 2 2 2 2 zinc oxide 2 2 2 2 2 Antioxidant 2 2 2 2 2 Processing aid 1 ⁽⁸⁾ 3 3 3 3 3 Processing aid 2 ⁽⁹⁾ 4 4 4 4 4 Oil ⁽¹⁰⁾ 29.0 29.0 2.75 2.75 2.75 Vulcanizing agent (sulfur) ⁽¹¹⁾ 1.3 1.3 1.3 1.3 1.3 The vulcanization accelerator 1 ⁽¹²⁾ One One One One One Vulcanization accelerator 2 ⁽¹³⁾ 2.5 2.5 2.5 2.5 2.5

(1) S-SBR: a styrene-butadiene copolymer having a weight average molecular weight of 4.6 x 10 ⁵ g / mol, a molecular weight distribution of 1.3, a styrene content of 20%, a vinyl content of 56% and a glass transition temperature of -35 캜, butadiene rubber (HPR350 ^®, JSR Inc.)

(2) S-SBR: styrene-butadiene copolymer having a weight average molecular weight of 5.5 x 10 ⁵ g / mol, a molecular weight distribution of 1.6, a styrene content of 20%, a vinyl content of 56% and a glass transition temperature of -35 캜, Butadiene rubber (SOL 5251H ^® , KKPC Inc.)

(3) S-SBR having a weight average molecular weight of 9.5 x 10 ⁵ g / mol, a molecular weight distribution of 1.8, a styrene content of 20%, a vinyl content of 56% and a glass transition temperature of -35 캜, End modified styrene-butadiene rubber (MF1847E-J, LG Chem) containing 37.5 parts by weight of a styrene-

(4) BR: Butadiene rubber (CB25 ^® , LANXESS Inc.)

(5) Carbon black: Carbon black particles (iodine adsorption value 90 mg / g, oil adsorption specific surface area (OAN) 120 cc / 100 g, pour density 340 g / dm ³ )

(6) Silica: silica (20 MP, Solvay) having a nitrogen adsorption specific surface area of 220 m ² / g and a CTAB adsorption specific surface area of 200 m ² / g,

(7) Silane coupling agent: tetrasulfide compound (Si69 ^® , Evonik) having a sulfur content of 23% by weight and a molecular weight of 535 g / mol,

(8) Processing aid 1: Zinc fatty acid fatty acid soap (HT276 ^® , Struktol)

(9) Processing aid 2: Fatty acid zincation / potassium soap (EF-44, Dong-Eun Chemical) for improving processability and dispersibility

(10) Oil: Residual Aromatic Extract (Korea Shell Oil Co., Ltd.)

(11) Vulcanizing agent (sulfur): Ground sulfur

(12) Vulcanization accelerator 1: N-cyclohexyl-2-benzothiazoylsulfanamide (available from SHANDONG SHANXIAN CHEMICALS)

(13) Vulcanization accelerator 2: diphenylguanidine (manufactured by SHANDONG SHANXIAN CHEMICALS)

Evaluation example  One

(Mooney viscosity)

The Mooney viscosity (ML 1 + 4 (100 ° C)) of the rubber composition for a tire prepared in Examples 1 to 7 and Comparative Examples 1 to 4 was measured according to ASTM Specification D 1646. ML 1 + 4 was the viscosity The lower the value, the better the workability of unvulcanized rubber. The results are shown in Tables 3 and 4 below.

Evaluation example 2

The rubber compositions for tires prepared in Examples 1 to 7 and Comparative Examples 1 to 4 were press vulcanized at 160 DEG C for 15 minutes in molds (15 cm x 15 cm x 0.2 cm) to prepare vulcanized rubbers, respectively. The hardness, 300% modulus, elongation, tensile strength, breaking strength, abrasion and viscoelasticity of each vulcanized rubber were measured by the following methods, and the results are shown in Tables 3 and 4 below.

(Hardness)

The hardness was measured by a Shore A type hardness tester. The hardness indicates the stability of the specimen to the rigidity of the specimen. The higher the value, the better the stability of the manipulation.

(300% modulus)

The 300% modulus was measured by ASTM Specification D 412 as the tensile strength at 300% elongation, and the higher the value, the better the strength.

(Elongation)

The elongation was measured by a method of indicating the strain value in% in the tensile tester until the test piece was broken.

(The tensile strength)

The tensile strength was measured as a stress value until the test piece was broken in a tensile tester.

(Wear)

The wear rate was tested by increasing the test severity in the order of Akron, Lambourn, Din and William abrasion tester abrasion tester and measuring the loss of abrasion rubber at room temperature The lower the value, the better the wear performance.

(Viscoelastic)

The viscoelasticity was measured with a Gabo viscometer at a temperature of -80 ° C to 70 ° C under a 10 Hz frequency with a 0.2% strain. In this case, the temperature at which the largest value of Tan δ is defined as the glass transition temperature, and the value of Tan δ at 0 ° C. indicates that the braking performance is excellent on the road surface. The smaller the value of Tan δ at 60 ° C., This indicates that the heat resistance is low and the rotation resistance is excellent.

<Two-end Modification Application and Solution Polymerization Measurement of rubber properties according to molecular weight of styrene-butadiene rubber>

division Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 Mooney viscosity (100 DEG C) 53 57 63 62 61 63 Hardness (Shore A) 64 64 64 65 64 64 300% modulus (kgf / cm ² ) 90 91 99 104 102 96 Tensile strength (kgf / cm ² ) 187 192 190 195 194 191 Elongation (%) 530 530 490 480 490 490 Wear (William,%) 0.789 0.733 0.679 0.659 0.635 0.615 Wear (Din,%) 0.647 0.638 0.605 0.599 0.585 0.570 Wear (Lambourn,%) 0.129 0.121 0.117 0.115 0.111 0.109 Wear (Akron,%) 0.109 0.103 0.100 0.098 0.096 0.095 The glass transition temperature (Tg) -24 -23 -23 -24 -26 -26 Viscoelastic tanδ @ 0 C 0.299 0.312 0.309 0.302 0.299 0.298 tanδ @ 20 ℃ 0.191 0.208 0.193 0.193 0.194 0.194 tanδ @ 60 ° C 0.138 0.135 0.126 0.120 0.118 0.119

As shown in Table 3, the vulcanized rubbers prepared from the rubber composition for tire tread of Examples 1 to 4 were superior to the vulcanized rubbers prepared from the rubber composition for tire treads of Comparative Examples 1 and 2 while maintaining the same adjustment stability Strength, abrasion resistance and rotational resistance.

In addition, in the case of the vulcanized rubber produced from the rubber composition for tire tread of Examples 1 to 4, the higher the weight average molecular weight of the solution-polymerized styrene-butadiene rubber contained in the rubber composition, the better the abrasion resistance was. The abrasion loss was increased with increasing degree of severity in the test machines with different wear severity. Especially, the wear abrasion improving effect was the largest in the William abrasion tester tester with the greatest severity.

<Application of Both End Modification and Measurement of Physical Properties of Rubber According to Silica Content>

division Comparative Example 3 Comparative Example 4 Example 5 Example 6 Example 7 Mooney viscosity (100 DEG C) 59 63 75 76 79 Hardness (Shore A) 66 66 68 71 74 300% modulus (kgf / cm ² ) 115 121 125 121 118 Tensile strength (kgf / cm ² ) 192 198 193 200 194 Elongation (%) 420 410 420 450 450 Wear (William,%) 0.793 0.787 0.675 0.657 0.646 Wear (Din,%) 0.644 0.645 0.600 0.579 0.571 Wear (Lambourn,%) 0.129 0.128 0.117 0.114 0.112 Wear (Akron,%) 0.118 0.116 0.108 0.105 0.102 The glass transition temperature (Tg) -23 -20 -23 -24 -22 Viscoelastic tanδ @ 0 C 0.324 0.325 0.323 0.351 0.378 tanδ @ 20 ℃ 0.203 0.201 0.205 0.215 0.228 tanδ @ 60 ° C 0.119 0.116 0.090 0.105 0.120

As shown in Table 4, the vulcanized rubbers prepared from the rubber composition for tire tread of Examples 5 to 7 had the same excellent adjustment stability as the vulcanized rubber prepared from the rubber composition for tire tread of Comparative Examples 3 and 4 Strength, abrasion resistance and rotational resistance.

Further, in the case of the vulcanized rubber prepared from the rubber composition for tire treads of Examples 5 to 7, the higher the content of silica contained in the rubber composition, the better the abrasion resistance and braking performance.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the appended claims. It will be understood that the present invention can be changed.

1: bead portion
2: side wall portion
3: tire tread portion
4: carcass layer
5: Bead core
6: Bead filler
7: Belt layer
8: lip cushion

Claims (10)

100 parts by weight of a starting rubber comprising 50 to 95 parts by weight of styrene-butadiene rubber and 5 to 50 parts by weight of butadiene rubber; And
And 60 to 100 parts by weight of silica relative to 100 parts by weight of the raw material rubber
Wherein the weight average molecular weight of the solution-polymerized styrene-butadiene rubber at both ends is 700,000 to 950,000 g / mol. The method according to claim 1,
Wherein the both terminals are modified with at least one functional group selected from the group consisting of a carboxyl group, a hydroxyl group, an amine group, an alkoxyl group, a silanol group, a sulfonyl group, tin (Sn) and silicon. 3. The method of claim 2,
Wherein the content of the functional group is 10 to 30 parts by weight based on 100 parts by weight of the solution-polymerized styrene-butadiene rubber. The method according to claim 1,
Wherein the solution-polymerized styrene-butadiene rubber has a molecular weight distribution of 1.5 to 1.9. The method according to claim 1,
Wherein the solution-polymerized styrene-butadiene rubber is a continuous polymer. The method according to claim 1,
Wherein the solution-polymerized styrene-butadiene rubber has a styrene content of 10 to 30% by weight and a glass transition temperature of -45 to -25 占 폚. The method according to claim 1,
Wherein said solution polymerized styrene-butadiene rubber further comprises 20.0 to 50.0 parts by weight of treated distillate aromatic extract (TDAE) oil per 100 parts by weight of rubber solids. The method according to claim 1,
Wherein the silica has a nitrogen adsorption specific surface area of 210 to 230 m &lt; 2 &gt; / g and a CTAB (cetyltrimethyl ammonium bromide) adsorption specific surface area of 190 to 210 m 2 / g. The method according to claim 1,
Wherein the rubber composition for tire tread further comprises carbon black or a silane coupling agent. A tire produced from the rubber composition for a tire tread according to any one of claims 1 to 9.

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