KR20170036270A - Rubber composition for tire tread and tire manufactured by using the same - Google Patents

Abstract

The present invention relates to a rubber composition for tire tread and a tire manufactured by using the same. The rubber composition for tire tread comprises 100 parts by weight of raw rubber, 50 to 100 parts by weight of carbon black and 40 to 300 parts by weight of a wet master batch including latex in which an end group of high molecular weight polymer latex is modified into a liquid styrene butadiene copolymer. Accordingly, the rubber composition for tire tread has low rotational resistance and high braking performance on the wet surface.

Description

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

The present invention relates to a rubber composition for a tire tread having improved performance and durability of a rubber composition for a tire tread, and a tire produced using the same.

Generally, carbon black or silica is used as the filler of the tire rubber composition. When silica is used as the filler, the chemical reaction of silica in the composition should be induced well. Many chemicals are used in the rubber composition. Among them, zinc oxide (ZnO) and stearic acid (stearic acid) are adsorbed on the surface of silica when they are present together with silica to lower the reaction of silica. If the silanization reaction of the silica surface by zinc oxide and stearic acid does not occur, low rolling resistance and excellent wet road surface braking characteristics, which are advantages of silica compound tires, can not be exhibited.

Prior art relating to master batching of rubber compositions is disclosed in Korean Patent Laid-Open No. 10-2003-0042909, which relates to a rubber composition for insoluble sulfur master batches containing a vulcanization retarder. The prior art document aims to maintain the residual ratio of insoluble sulfur to prevent the blooming phenomenon. Korean Patent Laid-Open No. 10-2011-0053129 discloses a tire tread rubber composition prepared by using a styrene butadiene latex-silica-starch-silane coupling agent wet master batch to improve abrasion resistance and dynamic properties.

Korean Patent Publication No. 10-2003-0042909 (Jun. 2003) Korean Patent Publication No. 10-2011-0053129 (2011.05.19)

It is an object of the present invention to provide a rubber composition for a tire tread having improved dispersibility and processability.

It is another object of the present invention to provide a rubber composition for a tire tread having a high glass transition temperature and maintaining a high endurance performance and grip performance even at high speed / long time running.

It is still another object of the present invention to provide an ultra high performance tire manufactured 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 comprises 100 parts by weight of raw rubber, 50 to 100 parts by weight of carbon black, and 40 to 300 parts by weight of a wet master batch, The batch provides a rubber composition for a tire tread wherein the terminal group of the high molecular weight polymer latex comprises a latex modified with a liquid styrene butadiene copolymer.

The high molecular weight polymer latex may have a weight average molecular weight of 200 to 1200 g / mol.

The high molecular weight polymer latex may be any one selected from the group consisting of natural latex, styrene butadiene latex, and isoprene latex.

The liquid styrene butadiene copolymer may be substituted with a hydroxyl group.

The hydroxyl group may be substituted with 20 to 50 mol% of the entire liquid styrene butadiene copolymer.

The liquid styrene-butadiene copolymer may have a glass transition temperature (Tg) of -20 to -10 ° C.

The modified latex may be a link of a terminal group of the high molecular weight polymer latex and a terminal group of the liquid styrene butadiene copolymer.

The terminal group of the liquid styrene-butadiene copolymer may be a hydroxyl group.

The wet master batch may comprise 50 to 200 parts by weight of carbon black and 50 to 200 parts by weight of a processing oil based on 100 parts by weight of the latex modified with a liquid styrene butadiene copolymer at the terminal group of the high molecular weight polymer latex .

The rubber composition for a tire tread may further comprise a second wet master batch other than the wet master batch in which the terminal group of the high molecular weight polymer latex comprises a latex modified with a liquid styrene butadiene copolymer.

The second wet masterbatch may be one comprising latex, carbon black and oil.

Wherein the rubber composition for tire tread comprises 15 to 600 parts by weight of the second wet master batch relative to 100 parts by weight of the wet master batch comprising the latex modified with a liquid styrene butadiene copolymer at the terminal of the high molecular weight polymer latex .

The rubber composition for a tire tread further comprises 0.5 to 4 parts by weight of a vulcanizing agent, 0.5 to 4.0 parts by weight of a vulcanization accelerator, 1 to 20 parts by weight of a silane coupling agent and 1 to 150 parts by weight of a softening agent based on 100 parts by weight of the raw rubber Lt; / RTI >

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

The present invention can provide a rubber composition for a tire tread having improved dispersibility and processability.

The rubber composition for tire tread of the present invention can maintain high durability performance and high grip performance even at high speed / long time running.

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

The rubber composition for a tire tread according to one embodiment of the present invention comprises 100 parts by weight of raw rubber, 50 to 100 parts by weight of carbon black, and 40 to 300 parts by weight of a wet master batch, wherein the wet master batch comprises high molecular weight polymer latex (Iii) a latex modified with a high Tg liquid polymer (ii). The rubber composition for a tire tread according to claim 1, wherein the latex (iii) is a latex modified with a high Tg liquid polymer (ii).

The raw material rubber may be any one selected from the group consisting of natural rubber, synthetic rubber, and combinations thereof. Preferred are polyisoprene rubber, polybutadiene rubber, conjugated diene aromatic vinyl copolymer, nitrile conjugated diene copolymer, hydrogenated nitrile rubber (H-NBR), olefin rubber, ethylene-propylene rubber modified with maleic acid, butyl rubber, A rubber, a copolymer of isobutylene and an aromatic vinyl or diene monomer, an acrylic rubber, an ionomer, a halogenated rubber and a chloroprene rubber.

(Carbon black) such as SAF, ISAF, HAF, MAF, FEF, SRF, GPF, APF, FF, CF, SCF and ECF as the rubber composition for a tire tread; Acetylene black (acetylene carbon black); Thermal blacks such as FT and MT (thermal carbon black); Channel blacks such as EPC, MPC and CC (channel carbon black); Graphite, but may preferably be HAF (High Abrasion Furnace) carbon black.

The HAF carbon black has excellent abrasion resistance and excellent heat resistance, which is suitable for the accumulation of generated heat in accordance with the periodic stress load of the tire.

More preferably, the HAF carbon black may have a specific surface area of 80 to 120 m 2 / g, or 80 to 100 m 2 / g. When the specific surface area of the HAF carbon black is less than 80 m < 2 > / g, there is a risk of cracking. When the specific surface area exceeds 120 m / g,

The carbon black may be contained in an amount of 50 to 100 parts by weight based on 100 parts by weight of the raw rubber. If the content of carbon black is less than 50 parts by weight, the effect of improving the reinforcing performance of the tire due to the use of carbon black is insignificant. If the content exceeds 100 parts by weight, the workability of the rubber composition may be deteriorated.

The wet master batch comprises a latex (iii) wherein the terminal group of the high molecular weight polymer latex (i) is modified with a liquid styrene butadiene copolymer (ii).

The high molecular weight polymer latex (i) may have a weight average molecular weight of 200 to 1200 g / mol.

When the weight average molecular weight is less than 200 g / mol, a problem of lowering the workability may occur, and when the weight average molecular weight is more than 1200 g / mol, dispersion in the master batch may be difficult.

More specifically, the high molecular weight polymer latex may be any one selected from the group consisting of natural latex, styrene butadiene latex and isoprene latex.

The high molecular weight polymer latex may be an emulsion or a solution.

The liquid styrene butadiene copolymer (ii) may be substituted with a hydroxyl group, and the hydroxyl group may be substituted with 20 to 50 mol% of the entire liquid styrene butadiene copolymer (ii).

If the hydroxyl group is replaced by 20 mol% or less, the reaction may not occur. If the hydroxyl group is substituted by 50 mol% or more, the substitution may lead to a problem of deterioration of physical properties due to byproducts.

The hydroxyl-substituted liquid styrene-butadiene copolymer (ii) preferably has a high glass transition temperature, and more specifically, may have a glass transition temperature (Tg) of -20 to -10 ° C.

When the glass transition temperature is less than -20 ° C, the tire grip of the finished product may be delayed. If the glass transition temperature is higher than -10 ° C, plasticization may occur.

However, since the liquid styrene-butadiene copolymer (ii) substituted with the hydroxyl group has a high styrene content, it is difficult to handle with high viscosity, and therefore, when used in combination, the disadvantage in various aspects such as processability, handling, have. Accordingly, when the liquid styrene-butadiene copolymer (ii) whose surface is substituted with a hydroxyl group is used alone, the processability and dispersibility may be extremely disadvantageous. In order to solve such a problem, the present invention is applied to a wet master batch, and when used alone, acts as a single molecule in a rubber composition for a tread, which may result in a rapid durability deterioration.

In order to solve the above problems, the rubber composition for a tire tread according to the present invention uses a modified latex (iii).

The modified latex (iii) may be one in which the terminal group of the high molecular weight polymer latex (i) is linked to the terminal group of the liquid styrene butadiene copolymer (ii).

The terminal group of the liquid styrene-butadiene copolymer (ii) is preferably a hydroxyl group.

The terminal group of the high molecular weight polymer latex may be an alkyl group, and may preferably be a methyl group (-CH ₃ ). The methyl group is modified by reacting with the hydroxyl group of the liquid styrene butadiene copolymer.

Linking the end group of the high molecular weight polymer latex (i) with the liquid styrene butadiene copolymer (ii) substituted with the hydroxyl group, and then combining the end groups of the high molecular weight polymer latex (i) with the master batch in the latex (iii) It is possible to solve the problems mentioned above (problems of dispersibility, processability and durability deterioration), and at the same time, durability and grip performance can be maintained when running for a long time (24 hours or more).

The wet master batch may contain 50 to 200 parts by weight of carbon black and 50 to 200 parts by weight of a processing oil based on 100 parts by weight of the latex (iii) in which the high molecular weight polymer latex terminal group is modified with a liquid styrene butadiene copolymer .

If the amount of the carbon black is less than 50 parts by weight, the reinforcing property may be deteriorated. If the amount is more than 200 parts by weight, the master batch processability may be deteriorated.

The rubber composition for a tire tread may further comprise a second wet master batch other than the wet master batch in which the terminal group of the high molecular weight polymer latex comprises a latex modified with a liquid styrene butadiene copolymer.

The second wet masterbatch may be one comprising latex, carbon black and oil.

Wherein the rubber composition for tire tread comprises 15 to 600 parts by weight of the second wet master batch relative to 100 parts by weight of the wet master batch comprising the latex modified with a liquid styrene butadiene copolymer at the end groups of the high molecular weight polymer latex .

The tire rubber composition may further include various additives such as additional vulcanizing agents, vulcanization accelerators, vulcanization accelerators, anti-aging agents, softening agents and the like. Any of the various additives may 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 is dependent on the blending ratio used in a conventional rubber composition for a tire.

As the vulcanizing agent, metal oxides such as sulfur vulcanizing agents, organic peroxides, resin vulcanizing agents, and magnesium oxide can be used.

The sulfur vulcanizing agent is an inorganic vulcanizing agent such as powder sulfur (S), insoluble sulfur (S), precipitated sulfur (S), colloid sulfur, etc., tetramethylthiuram disulfide (TMTD) Organic vulcanizing agents such as tetraethyltriuram disulfide (TETD) and dithiodimorpholine can be used. 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 organic peroxide is selected from the group consisting of benzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, t-butyl cumyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, 2,5- butylperoxy) hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5- Bis (t-butylperoxypropyl) benzene, di-t-butylperoxy-diisopropylbenzene, t-butylperoxybenzene, 2,4-dichlorobenzoylperoxide, 1,1- , 3,5-trimethylsiloxane, n-butyl-4,4-di-t-butylperoxyvalerate, and combinations thereof.

It is preferable that the vulcanizing agent is included in an amount of 0.5 to 4.0 parts by weight based on 100 parts by weight of the raw rubber, in view of a suitable vulcanizing effect because the raw rubber is less sensitive to heat and chemically stable.

The vulcanization accelerator refers to an accelerator that promotes the vulcanization rate or accelerates the retardation in the initial vulcanization step.

Examples of the vulcanization accelerator include sulfenamide, thiazole, thiuram, thiourea, guanidine, dithiocarbamate, aldehyde-amine, aldehyde-ammonia, imidazoline, Or a combination thereof.

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

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

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

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

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

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

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

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

The vulcanization accelerator may be included in an amount of 0.5 to 4.0 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 master batch of the present invention contains zinc oxide and stearic acid which are the vulcanization accelerators and does not require a separate vulcanization accelerator, but may additionally include them.

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 to complete the promoting effect of the vulcanization accelerator in combination with the vulcanization accelerator.

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 the zinc oxide and the stearic acid are used together, they may be used in an amount of 1 to 5 parts by weight and 0.5 to 3 parts by weight, respectively, based on 100 parts by weight of the raw rubber to serve as a proper vulcanization accelerator.

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 3 wt% or more together with the increase in environmental consciousness, Treated distillate aromatic extract (TDAE) oil, mild extraction solvate (MES) oil, residual aromatic extract (RAE) oil or heavy naphthenic oil.

Particularly, the oil used as the 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 oil include vegetable oils such as castor oil, cottonseed oil, linseed oil, canola oil, soybean oil, palm oil, palm oil, peanut oil, pine oil, pine tar, tall oil, cone oil, rice bran oil, safflower oil, sesame oil, , Jojoba oil, macadamia nut oil, four flower oil, tung oil, and combinations thereof.

It is preferable that the softening agent is used in an amount of 0 to 150 parts by weight based on 100 parts by weight of the raw material rubber in order to improve workability of the raw material rubber.

The rubber composition for a tire can be produced through a conventional two-step continuous production process. That is, during the finishing step in which a first step (referred to as a "non-production" step) of thermomechanical treatment or kneading at a maximum temperature of 110-190 ° C, preferably 130-180 ° C, and a crosslinking system are mixed, Can be prepared in a suitable mixer using a second stage (referred to as the "production" step) of mechanically treating at a low temperature, typically below 110 ° C, for example 40-100 ° C, but the invention is not so limited .

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

A method of manufacturing a tire including a tread portion using the rubber composition for a tire tread can be applied to any method conventionally used for manufacturing a tire, and a detailed description thereof will be omitted herein.

Preferably, the tire is an ultra high performance tire (UHP Tire) or a racing tire.

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 tires according to the following Examples and Comparative Examples were prepared using the compositions shown in Table 1 below. The production of the rubber composition is in accordance with the usual production method of the rubber composition, and is not particularly limited.

Item Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Raw rubber ¹⁾ 51.6 51.6 51.6 51.6 51.6 51.6 51.6 Carbon black ²⁾ 57.5 57.5 57.5 57.5 57.5 57.5 57.5 Wet master batch 1 ³⁾ - 20 60 80 100 120 150 Wet master batch 2 ⁴⁾ 150 120 100 80 60 20 - TDAE oil 35.9 35.9 35.9 35.9 35.9 35.9 35.9 Zinc oxide 3.0 3.0 3.0 3.0 3.0 3.0 3.0 Stearic acid 2.0 2.0 2.0 2.0 2.0 2.0 2.0 brimstone 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Accelerator 1 ⁵⁾ 2.5 2.5 2.5 2.5 2.5 2.5 2.5 Promoter 2 ⁶⁾ 0.6 0.6 0.6 0.6 0.6 0.6 0.6

(Unit: parts by weight)

1) Raw material rubber: stadiene rubber (styrene content 37.5%, oil content 50%)

2) Carbon black: N220 (N2SA: 111 m < 2 > / g)

3) Wet master batch 1: Wet master batch comprising modified latex of a high molecular weight polymer latex (emulsion styrene butadiene latex having a weight average molecular weight of 14,000 g / mol) modified with a liquid styrene butadiene copolymer (modified latex: carbon Black: oil = 100: 140: 140)

4) Wet master batch 2: CB24 (polymer latex: carbon black: oil = 100: 140: 140)

5) Accelerator 1: TT (Tiuram-based vulcanization accelerator)

6) Accelerator 2: ZBEC (dithiocarbamate-based vulcanization accelerator)

[ 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 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Initial Dry grip performance ^{1 )} 1.0 8.5 10 9.0 8.0 7.0 6.5 Dry grip performance in the second half ^{1 )} 1.5 7.0 9.0 9.0 7.0 6.5 5.0 Endurance performance
(Driver comment) ²⁾ 3 4 6 8 8.5 9.2 9.0 300% modulus (Mpa) ^{3 )} 50.7 62.2 67.3 71.1 69.4 72.1 74.3 Elongation percentage (%) ⁴⁾ 790 861 839 821 801 760 742 Wear Index ^{5 )} 100 163 172 186 169 159 148

1) Dry (dry road surface) grip performance: Using the above rubber composition and using tire size 280 / 680R18 F200 with a tread part, air pressure was set at 200 kPa, and the test driver was allowed to drive the circuit course (5.615 km) The lap time was measured at each running time, and the initial grip performance and the sustainability of the grip performance were evaluated.

* Grip Performance Score Table: 1 (very bad) ~ 10 (very good)

2) Durability (driver comment): After 10 lap driving, the driver rated the braking, steering response and balance.

* Grip Performance Score Table: 1 (very bad) ~ 10 (very good)

3) 300% modulus: elongation was measured by ISO 37 standard.

4) Wear rate: Measured according to JIS K6264.

As shown in Table 2, in Examples 1 to 6 using a master batch containing a latex modified with a high-tg liquid polymer as a high molecular weight polymer latex terminal group as compared with Comparative Example 1, The grip performance was increased. However, when the wet master batch 1 was used in an amount of 80 parts by weight or more, it was confirmed that the grip performance was somewhat lowered.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

Claims (14)

100 parts by weight of the raw rubber,
50 to 100 parts by weight of carbon black, and
40 to 300 parts by weight of a wet master batch,
Wherein the wet masterbatch comprises a latex in which the terminal group of the high molecular weight polymer latex is modified with a liquid styrene butadiene copolymer. The method according to claim 1,
Wherein the high molecular weight polymer latex has a weight average molecular weight of 200 to 1200 g / mol. The method according to claim 1,
Wherein the high molecular weight polymer latex is any one selected from the group consisting of natural latex, styrene butadiene latex and isoprene latex. The method according to claim 1,
Wherein the liquid styrene butadiene copolymer is substituted with a hydroxyl group. 5. The method of claim 4,
Wherein the hydroxyl group of the liquid styrene-butadiene copolymer is substituted with 20 to 50 mol%. The method according to claim 1,
Wherein the liquid styrene-butadiene copolymer has a glass transition temperature (Tg) of -20 to -10 ° C. The method according to claim 1,
Wherein the modified latex is formed by linking the terminal groups of the high molecular weight polymer latex and the terminal groups of the liquid styrene butadiene copolymer. 8. The method of claim 7,
Wherein the terminal end of the liquid styrene-butadiene copolymer is a hydroxyl group. The method according to claim 1,
In the wet master batch,
Based on 100 parts by weight of the latex modified with a liquid styrene-butadiene copolymer at the terminal group of the high molecular weight polymer latex,
50 to 200 parts by weight of carbon black, and
50 to 200 parts by weight of the process oil
≪ / RTI > The method according to claim 1,
Wherein the rubber composition for a tire tread further comprises a second wet masterbatch other than a wet masterbatch wherein the terminal group of the high molecular weight polymer latex comprises a latex modified with a liquid styrene butadiene copolymer. 11. The method of claim 10,
Wherein the second wet masterbatch comprises latex, carbon black and oil. 11. The method of claim 10,
The rubber composition for a tire tread includes 15 to 600 parts by weight of the second wet master batch relative to 100 parts by weight of the wet master batch containing the latex modified with a liquid styrene butadiene copolymer as a terminal group of the high molecular weight polymer latex A rubber composition for an internal tire tread. The method according to claim 1,
The rubber composition for a tire tread further comprises 0.5 to 4 parts by weight of a vulcanizing agent, 0.5 to 4.0 parts by weight of a vulcanization accelerator, 1 to 20 parts by weight of a silane coupling agent and 1 to 150 parts by weight of a softening agent based on 100 parts by weight of the raw rubber Lt; RTI ID = 0.0 > tread < / RTI > A tire produced by using the rubber composition for a tire tread according to claim 1.