KR101338955B1 - 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 rubber composition includes 75 to 82 parts by weight of an emulsion polymerization styrene butadiene rubber, 18 to 25 parts by weight of butadiene rubber, 5 to 11 parts by weight of a softener, 63 to 79 parts by weight of filler, and 0.1 to 1.9 parts by weight of vulcanization accelerator, wherein the emulsion polymerization styrene butadiene rubber has a polycyclic aromatic hydrocarbon content of less than 10 mg / kg, and has a kinematic viscosity of 95 (210 ° F.) or more. , An oil comprising 25 to 35 parts by weight of an aromatic component, 21 to 31 parts by weight of a naphthenic component, and 39 to 47 parts by weight of a paraffinic component.
The tire tread rubber composition may improve the wear resistance, low fuel efficiency and braking performance of the tire while being environmentally friendly by minimizing the emission of PAH and nitrosoamine.

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 a tire tread and a tire manufactured using the same, and more particularly, to minimize the emission of polycyclic aromatic hydrocarbons and nitrosoamines, thereby improving environmentally friendly wear resistance, low fuel consumption, and braking performance. The present invention relates to a rubber composition for tire treads, and a tire made using the same.

Recently, with high performance of passenger cars, consumers are demanding high performance of tires, and in particular, consumers are demanding tires having both stability (braking performance) and low fuel consumption.

However, each performance of a tire tends to degrade one performance and the other. For example, when the rubber having a low glass transition temperature (Tg) is used, wear resistance and low fuel consumption of the tire may be improved, but stability (braking property) is rather deteriorated. Due to these characteristics, developing a technology that can improve one performance while minimizing the other performance degradation or improve several performances at the same time has become an important key to the progress of the technology in the tire rubber composition.

On the other hand, in Europe, there is an increasing demand for the use of environment-friendly materials in relation to environmental regulations.

Various kinds of softeners are used as additives of the rubber composition for tire treads. Among them, aromatic oils are generally used in that processability and optimum properties can be realized in refining and extrusion processes.

However, polycyclic aromatic hydrocarbons (PAH) contained in aromatic oils are known to cause cancer if they enter the human body, the European Rubber Association (BRIC) is taking measures. The European Union has also formulated a specific use regulation to prohibit the sale of softeners used in rubber compositions when the oil extracted by the dimethylsulfoxide (DMSO) extraction method has a polycyclic aromatic content of more than 10 mg / Kg. The system has been legalized. Accordingly, all tire makers consider urgent problems to minimize the polycyclic aromatic content in the additives used in the manufacture of tires.

In addition, nitroso amine is generated in the vulcanization process of the tire manufacturing process, which is also known as a carcinogenic substance. The German government is now in the environmental regulatory range (TRGS 552) for calendaring, extrusion, molding, salt baths, UHF Curing areas and wirehousing areas. The level of nitrosoamines emitted from areas, etc., is regulated to 2.5 µg / m 3 or less, and the rubber industry requires that the limit of 1 µg / m 3 be kept. Since the German regulatory measures show signs of regulation in Europe and the United States, the issue of limiting emissions of nitrosoamines is also a major problem in the global rubber industry along with the problems related to polycyclic aromatic hydrocarbons.

As a method for minimizing the polycyclic aromatic content in the additives used in tire production, a method using an oil containing low PAH as a softener has been used (Japanese Patent Laid-Open No. 1999-302459 (Patent Document 1)). Reference). However, since this method replaced only the process oil containing low PAH in the tire tread rubber composition, there was a problem that the performance of the tire such as adjustment stability was lowered.

In order to solve this problem, various methods have been developed and proposed to improve the performance of tires by controlling the structure and composition of raw rubber together when using a softener containing low PAH (Korean Patent Publication No. 771699 ( See Patent Document 2) and Japanese Patent Application Laid-Open No. 2010-241965 (Patent Document 3).

In addition, regarding the suppression of the generation of nitrosoamines, Korean Patent Registration No. 339043 (Patent Document 4) discloses a secondary amine structure related to the production of nitrosoamines in a rubber composition for tires using natural rubber as a raw material rubber. A rubber composition for tires comprising a compound having no crosslinking agent is disclosed.

Patent Document 1: Japanese Patent Laid-Open No. 1999-302459 Patent Document 2: Korean Patent Publication No. 771699 Patent Document 3: Japanese Patent Publication No. 2010-241965 Patent Document 4: Korean Patent Registration No. 339043

SUMMARY OF THE INVENTION An object of the present invention is to provide a rubber composition for tire treads that can improve the environmentally friendly wear resistance, low fuel efficiency and braking performance by minimizing the emission of PAH and nitrosoamine.

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

In order to achieve the above object, the rubber composition for a tire tread according to an embodiment of the present invention, the emulsion polymerization styrene butadiene rubber 75 to 82 parts by weight, butadiene rubber 18 to 25 parts by weight, softener 5 to 11 parts by weight, filler 63 to 79 parts by weight, and 0.1 to 1.9 parts by weight of a vulcanization accelerator, wherein the emulsion polymerization styrene butadiene rubber has a polycyclic aromatic hydrocarbon content of less than 10 mg / kg, a kinematic viscosity of 95 (210 ° F.), An oil comprising 25 to 35 parts by weight of an aromatic component, 21 to 31 parts by weight of a naphthenic component, and 39 to 47 parts by weight of a paraffinic component.

The emulsion-polymerized styrene butadiene rubber may have a styrene content of 20 to 28 wt%, a vinyl content of at least 15 wt% in butadiene, and a glass transition temperature of -48 to -38 ° C.

The emulsion polymerization styrene butadiene rubber may include 25 to 60 parts by weight of the oil with respect to 100 parts by weight of the rubber component constituting the emulsion polymerization styrene butadiene rubber.

The butadiene rubber may have a weight average molecular weight of 600,000 or more, a molecular weight distribution of 3 to 5, and a glass transition temperature of -105 to -108 ° C.

The softener has a polycyclic aromatic hydrocarbon content of less than 10 mg / kg, kinematic viscosity of 95 (210 ° F) or more, 15 to 25% by weight of the aromatic component in the softener, 27 to 37% by weight of the naphthenic component, And paraffin component may be 38 to 58% by weight.

The filler may be a nitrogen adsorption specific surface area (N ₂ SA) of 90 to 95 m ₂ / g.

The vulcanization accelerators are tetrabenzylthiuram disulfide, tetrakis (2-ethylhexyl) thiuram disulfide, dibenzyldithiocarbamate zinc, tetrabenzyldithiocarbamate zinc, 1,6-bis (N, N-dibenzyl) The thiocarbamodithio) hexane and any one selected from the group consisting of a boiling point may be at least 300 ℃.

The vulcanization accelerator may include dithiocarbamic acid and sulfenamide vulcanization accelerators having a breaking point of 300 ° C. or more in a weight ratio of 1: 1 to 1:20.

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

Other details of the embodiments of the present invention are included in the following detailed description.

The rubber composition for tire tread of the present invention can minimize the discharge of PAH and nitrosoamine to improve environmentally friendly wear resistance, low fuel consumption and braking performance.

Hereinafter, embodiments of the present invention will be described in detail. However, this is presented as an example, by which the present invention is not limited and the present invention is defined only by the scope of the claims to be described later.

The inventors of the present invention have been researching for the development of tire high performance technology using environmentally friendly materials, as a result of using a styrene-butadiene rubber containing an oil having high purity, low temperature characteristics and fuel efficiency, but also environmentally friendly properties of the rubber composition It has been found that the abrasion and fuel economy performance can be improved, and the combination of the filler and the vulcanization accelerator in an optimum ratio can further improve the abrasion performance, and also by using the vulcanization accelerator having a high boiling point, The present invention has been completed by discovering that it is possible to prepare a rubber composition for tire tread that prevents the generation of nitrosoamines, which is environmentally friendly, shows equivalent vulcanization properties as compared to conventional rubber compositions, and improves not only the wear performance and the braking performance, but also the fuel efficiency. .

That is, the tire tread rubber composition according to the embodiment of the present invention, the emulsion polymerization styrene butadiene rubber 75 to 82 parts by weight, butadiene rubber 18 to 25 parts by weight, softener 5 to 11 parts by weight, filler 63 to 79 parts by weight, And 0.1 to 1.9 parts by weight of a vulcanization accelerator, wherein the emulsion polymerization styrene butadiene rubber has a polycyclic aromatic hydrocarbon content of less than 10 mg / kg, a kinematic viscosity of 95 (210 ° F.) or more, and an aromatic component 25 to 35. It is characterized in that it comprises an oil comprising a part by weight, 21 to 31 parts by weight of naphthenic component, and 39 to 47 parts by weight of paraffinic component.

Each component is demonstrated below.

The emulsion-polymerized styrene butadiene rubber (hereinafter referred to as 'E-SBR') is a conventional solution-polymerized styrene-butadiene rubber (hereinafter referred to as 'S-SBR') Compared with the low glass transition temperature (Tg) and the low vinyl content in butadiene, braking performance on wet roads is disadvantageous, but favorable for rotational resistance and wear performance. As the E-SBR, the present invention uses a low-purity styrene butadiene rubber having a low glass transition temperature (Tg) and containing environmentally friendly oils (hereinafter referred to as 'E-SBR C').

Specifically, the E-SBR C has a styrene content of 20 to 28% by weight, a vinyl content of butadiene of at least 15% by weight, preferably at least 18% by weight, and a glass transition temperature of -48 to -38 ° C. The E-SBR C may have a weight average molecular weight of 800,000 or more. When using the styrene content, butadiene vinyl content, glass transition temperature and the weight average molecular weight range of E-SBR C has an advantageous effect in terms of fuel efficiency, wear performance and braking performance.

In addition, the E-SBR C has a PAH content of less than 10 mg / kg, kinematic viscosity of 95 (210 ° F) or more, 25 to 35 parts by weight of aromatic components, 21 to 31 parts by weight of naphthenic components, and paraffinic component 39 Oils comprising from 47 parts by weight, preferably having a PAH content of at least 0.1 mg / kg and less than 10 mg / kg, a kinematic viscosity of 95-99 (210 ° F.), 27-33 parts by weight of an aromatic component, nap Oils comprising 23 to 29 parts by weight of ten-based components and 40 to 45 parts by weight of paraffinic components. More preferably, the oil has a PAH content of 10 mg / kg, a kinematic viscosity of 98 (210 ° F.), and contains 30 parts by weight of an aromatic component, 26 parts by weight of a naphthenic component, and 44 parts by weight of a paraffinic component. Aromatic Exatract) oil.

Compared with TDAE (Treated Distillate Aromatic Extract) oil, the TRAE oil has different glass transition temperature (Tg) due to the difference in aromatic, naphthenic, and paraffinic components, and is more excellent in terms of wear resistance and fuel efficiency. It works.

The oil may be included in an amount of 25 to 60 parts by weight, preferably 35 to 40 parts by weight, based on 100 parts by weight of the rubbery component ie, the styrene butadiene rubber constituting the emulsion polymerization styrene butadiene rubber except for the oil. When the E-SBR C includes the oil component in the content range, it can be expected to have an environmentally excellent effect, such as minimizing the amount of carcinogen emissions with increased flexibility of E-SBR C reduced by the influence of styrene.

The tire tread rubber composition according to the present invention also includes butadiene rubber (hereinafter referred to as 'BR') together with the emulsion polymerization styrene butadiene rubber.

The BR has a weight average molecular weight of 600,000 or more, preferably 700,000 or more, a molecular weight distribution of 3 to 5, and a glass transition temperature of -105 to -108 ° C. When the molecular weight, molecular weight distribution, and glass transition temperature range as described above are satisfied, a tread rubber composition having excellent fuel efficiency as well as wear and braking performance can be obtained.

The BR may be included in 18 to 25 parts by weight of the tire tread rubber composition. If the content of BR is less than 18 parts by weight, the wear performance may be lowered. If the content of BR is more than 25 parts by weight, the wet braking performance may be lowered.

The tire tread rubber composition according to the invention also contains a softener to impart plasticity to the rubber to facilitate processing and to lower the hardness of the vulcanized rubber.

The softener in the present invention is an oil included in rubber compounding or rubber manufacture, the content of polycyclic aromatic hydrocarbons (PAH) is less than 10 mg / kg, kinematic viscosity of 95 (210 ° F SUS) or more, and the aromatics in the softener 15-25 wt% of the component, 27-37 wt% of the naphthenic component, and 38-58 wt% of the paraffinic component. Preferably, a low PAH oil having a content of PAH of less than 10 mg / kg, an aromatic component of 20% by weight, a naphthenic component of 32%, and a paraffinic component of 48% by weight can be used.

Specific examples of the softener may be oils contained in process oil or other rubber compositions used in rubber compounding or rubber production under conditions satisfying the softener conditions. Oils, and mixtures thereof, may be used.

The vegetable oils include castor oil, cottonseed oil, linseed oil, canola oil, soybean oil, palm oil, palm oil, peanut oil, pine oil, pine tar, tall oil, corn oil, rice bran oil, safflower oil, sesame oil, olive oil, sunflower oil, palm kernel oil, camellia oil It may be used any one selected from the group consisting of jojoba oil, macadamia nut oil, saflower flower oil, tung oil and mixtures thereof.

In addition, the petroleum oil may be any one selected from the group consisting of paraffinic oil, naphthenic oil, aromatic oil and mixtures thereof.

Representative examples of the paraffinic oil include P-1, P-2, P-3, P-4, P-5, and P-6 of Michang Oil, Inc. A representative example of the naphthenic oil is Michang oil. And N-1, N-2, and N-3 of the Co., Ltd., and representative examples of the aromatic oils include A-2 and A-3 of Michang Oil Co., Ltd., and are also environmentally friendly TDAE (treated). Distillate aromatic extract (IL) oils, mild extraction solvate (MES) oils, treated residual aromatic extract (TRAE) oils or heavy naphthenic oils may be used.

The softener is preferably contained in 5 to 11 parts by weight in the rubber tread rubber composition to improve the flexibility and processability of the raw material rubber to improve the adjustment stability, wear performance and fuel economy performance of the rubber composition.

The tire tread rubber composition according to the invention also comprises a filler for improving the reinforcing properties and wear performance of the rubber composition.

Nitrogen surface area per gram (N ₂ SA) is used as the filler is 90 to 95 m ₂ / g. When the nitrogen adsorption specific surface area of the filler is less than 90 m 2 / g, reinforcing performance and wear resistance by the filler may be lowered, and when it exceeds 95 m 2 / g, the workability of the rubber composition may be lowered.

The filler may be selected from the group consisting of carbon black, silica, calcium carbonate, clay (aluminum hydrated silica), aluminum hydroxide, lignin, silicate, talc and mixtures thereof.

Specifically, when using silica as a filler, it is preferable to use a CTAB (cetyl trimethyl ammonium bromide) adsorption specific surface area of silica is 110 to 170 m 2 / g. If the CTAB adsorption specific surface area of the silica is less than 110 m 2 / g, the reinforcing performance by silica is insignificant, and if it exceeds 170 m 2 / g, the workability of the rubber composition may be deteriorated.

Ultrasil VN2 (manufactured by Degussa AG), Ultrasil VN3 (manufactured by Degussa AG), Z1165MP (manufactured by Rhodia) or Z165GR (manufactured by Rhodia) can be used as the commercially available products. .

In addition, when carbon black is used as the filler, it is preferable to use a DBP (n-dibutyl phthalate) oil absorption of 60 to 180 cc / 100 g. If the DBP oil absorption of the carbon black is less than 60cc / 100g, the reinforcing performance by the carbon black as a filler is insignificant, and if it exceeds 180cc / 100g, the workability of the rubber composition may be deteriorated.

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

The filler may be included in an amount of 63 to 79 parts by weight in the tire tread rubber composition in consideration of the mixing cost with the vulcanization accelerator. If the content of the filler is less than 63 parts by weight, the reinforcement performance improvement by the filler is insufficient, and the braking performance of the tire may be reduced. If the content is more than 79 parts by weight, the processability and wear performance of the rubber composition may be reduced.

The tire tread rubber composition according to the invention also comprises a vulcanization accelerator for promoting the vulcanization rate or for promoting the delay in the initial vulcanization step.

In the case of conventional vulcanization accelerators, the boiling point is low, so that secondary amines are easily released into the air during the vulcanization process. As a result, nitrosoamine, a carcinogenic substance, is generated. Therefore, in the present invention, by using a vulcanization accelerator having a high boiling point (° C.), it is possible to prevent the generation of nitroso amine, which is a carcinogenic substance generated during the vulcanization process. Specifically, the vulcanization accelerator usable in the present invention preferably has a boiling point of 300 ° C. or higher. Such vulcanization accelerators include thiuram disulfide compounds such as tetrabenzylthiuram disulfide and tetrakis (2-ethylhexyl) thiuram disulfide; Dithiocarbamic acid compounds such as zinc dibenzyldithiocarbamate and tetrabenzyldithiocarbamate; 1,6-bis (N, N-dibenzylthiocarbamothiothio) hexane (1,6-bis (N, N-dibenzylthiocarbamodithio) -hexane) and mixtures thereof may be used.

The vulcanization accelerator having a boiling point of 300 ° C. or higher may be used alone or in combination with a vulcanization accelerator which does not generate nitrosoamine in order to double the vulcanization effect.

Examples of vulcanization accelerators that do not generate nitrosoamines include N-cyclohexyl-2-benzothiazolylsulfenamide, N-tert-2-benzothiazolylsulfenamide, N, N'-dicyclohexyl-2-benzothiazolyl Sulfenamide compounds such as sulfenamide; Aldehyde-amine compounds such as hexamethylenetetramine and n-butylaldehyde-aniline condensate; Thiourea compounds such as N, N'-diphenylthiourea and N, N'-diethylthiourea; Guanidine-based compounds such as 1,3-di-o-tolylguanidine, 1,3-diphenylguanidine, di-o-tolylguanidine salt of dicatecholborate, and 1-o-tolylbiguanide; Xanthic acid compounds such as zinc butyl xanthate and zinc isopropyl xanthate; Thiazole compounds such as dibenzothiazyl disulfide (MBTS), 2-mercaptobenzothiazole, zinc salt of 2-mercaptobenzothiazole, and mixtures thereof can be used, and the compounds It is preferable to use a sulfenamide type compound among these.

When a mixture of a vulcanization accelerator having a boiling point of 300 ° C. or higher and a vulcanization accelerator that does not generate nitrosoamine is used, a vulcanization accelerator having a boiling point of 300 ° C. or higher and a vulcanization accelerator which does not generate nitrosoamine are 1: 1 to 1:20. It can be mixed and used by weight ratio, Preferably it can mix in the weight ratio of 1: 10-1: 15. At this time, it is preferable to use a dithiocarbamic acid compound as a vulcanization accelerator having a boiling point of 300 ° C. or higher, and a sulfenamide compound as a vulcanization accelerator which does not generate nitrosoamine. When the mixture is used in the mixing ratio as described above, it can exhibit excellent properties in terms of low fuel consumption, braking properties, wear resistance, and vulcanization time while suppressing the generation amount of nitrosoamine.

The vulcanization accelerator may be included in the tire tread rubber composition 0.1 to 1.9 parts by weight, preferably 1.1 to 1.5 parts by weight. When included within the content range it is possible to maximize the increase in productivity and rubber properties by promoting the vulcanization rate while minimizing the generation of nitrosoamine.

In addition, the rubber composition for tire treads according to the present invention may optionally further include various additives such as vulcanizing agents, vulcanization accelerators, coupling agents, anti-aging agents or pressure-sensitive adhesives. 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.

Specifically, as the vulcanizing agent, metal oxides such as sulfur vulcanizing agents, organic peroxides, resin vulcanizing agents, and magnesium oxide may be used. Preferably, sulfur vulcanizing agents may be used.

Preferably, the vulcanizing agent is included in the tire tread rubber composition in an amount of 0.5 to 5 parts by weight, and when included in the content range, the vulcanizing agent exhibits an appropriate vulcanizing effect, thereby making the rubber component less sensitive to heat and chemically stable.

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

In particular, zinc oxide and stearic acid may be used together as the vulcanization accelerator, in which case the zinc oxide is dissolved in the stearic acid to form an effective complex with the vulcanization accelerator, thereby producing favorable sulfur during the vulcanization reaction. It facilitates the crosslinking reaction of the rubber. When used together with the zinc oxide and the stearic acid may be used in the tire tread rubber composition 1 to 5 parts by weight and 0.5 to 3 parts by weight, respectively, to serve as a suitable vulcanization accelerator.

The coupling agent is an additive for increasing the dispersion of the filler, and specifically, a sulfide silane compound, a mercapto silane compound, a vinyl silane compound, an amino silane compound, a glycidoxy silane compound, a nitro silane compound, a chloro silane compound , Any one selected from the group consisting of methacrylic silane compounds and mixtures thereof can 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 Sisylethyl) disulfide, bis (4-trimethoxysilylbutyl) disulfide, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, 3-triethoxysilylpropyl-N, N-dimethyl Thiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 2-trimethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilyl Propylbenzothiazolyl tetrasulfide, 3-triethoxysilylpropylbenzothiazoltetrasulfide, 3-trimethoxysilylpropylmethacrylate monosulfide, 3-trimethoxysilylpropylmethacrylate monosulfide and mixtures thereof It may be any one selected from the group consisting of. The mercapto silane compound is 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane and mixtures thereof It may be any one selected from the group consisting of. The vinyl silane compound may be any one selected from the group consisting of ethoxysilane, vinyltrimethoxysilane and mixtures thereof. The amino silane compound is 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropyltri It may be any one selected from the group consisting of methoxysilane and mixtures thereof. The glycidoxy silane compounds include γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and γ-glycidoxypropylmethyldimethoxysilane And it may be any one selected from the group consisting of a mixture thereof. The nitro-based silane compound may be any one selected from the group consisting of 3-nitropropyltrimethoxysilane, 3-nitropropyltriethoxysilane, and mixtures thereof. The chloro-based silane compound is selected from the group consisting of 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 2-chloroethyltrimethoxysilane, 2-chloroethyltriethoxysilane, and mixtures thereof. It can be any one. The methacrylic silane compound is any one selected from the group consisting of γ-methacryloxypropyl trimethoxysilane, γ-methacryloxypropyl methyldimethoxysilane, γ-methacryloxypropyl dimethylmethoxysilane, and mixtures thereof Can be.

The coupling agent may be included in an amount of 1 to 20 parts by weight in the tire tread rubber composition to improve dispersibility of the filler. When the content of the coupling agent is less than 1 part by weight, the improvement of dispersibility of the filler may be insufficient, and the workability of the rubber may be reduced or the low fuel consumption performance may be reduced. When the content of the coupling agent is more than 20 parts by weight, the interaction between the filler and the rubber is so strong that the fuel efficiency is low. May be good, but the braking performance and the stability of adjustment can be very poor.

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

Specific examples of the anti-aging agent include N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine (N- (1,3-Dimethybutyl) -N'-phenyl-p-phenylenediamine, 6PPD), N-phenyl-n-isopropyl-p-phenylenediamine (3PPD), poly (2,2,4-trimethyl-1,2-dihydroquinoline (poly ( 2,2,4-trimethyl-1,2-dihydroquinoline, RD) etc. can be mentioned, One or a mixture of two or more of these can be used.

The anti-aging agent is included in the tire tread rubber composition in an amount of 1 to 10 parts by weight in consideration of conditions such as high solubility in rubber in addition to anti-aging action, low volatility, inert to rubber, and not inhibit vulcanization. Can be.

The pressure-sensitive adhesive further improves the tack performance between the rubber and the rubber, and contributes to the improvement of physical properties of the rubber by improving the mixing, dispersibility and processability of the additives. As the pressure-sensitive adhesive, natural resin-based pressure-sensitive adhesives such as rosin-based resins or terpene-based resins, and synthetic resin-based pressure-sensitive adhesives such as petroleum resins, coal tar, or alkylphenol-based resins may be used.

The rosin-based resin may be any one selected from the group consisting of rosin resin, rosin ester resin, hydrogenated rosin ester resin, derivatives thereof, and mixtures thereof. The terpene-based resin may be any one selected from the group consisting of terpene resins, terpene phenol resins, and mixtures thereof. The petroleum resin is aliphatic resin, acid modified aliphatic resin, alicyclic resin, hydrogenated alicyclic resin, aromatic (C9) resin, hydrogenated aromatic resin, C5-C9 copolymer resin, styrene resin, styrene copolymer resin and It may be any one selected from the group consisting of a mixture thereof. The coal tar may be a coumarone-indene resin. The alkyl phenol resin may be p-tert-alkyl phenol formaldehyde resin, the p-tert-alkyl phenol formaldehyde resin may be p-tert-butyl-phenol formaldehyde resin, p-tert-octyl-phenol formaldehyde and It may be any one selected from the group consisting of a mixture thereof.

The pressure-sensitive adhesive may be included in 2 to 4 parts by weight of the tire tread rubber composition. When the content of the pressure-sensitive adhesive is less than 2 parts by weight based on 100 parts by weight of the raw material rubber, the adhesive performance may be detrimental.

The rubber composition for tire treads having the composition as described above may be manufactured through a conventional two-step continuous manufacturing process. That is, during the finishing step in which the first step (referred to as the non-production step) and the crosslinking system are thermom mechanically treated or kneaded at a maximum temperature of 110 to 190 캜, preferably at a high temperature of 130 to 180 캜, And a second step (referred to as a production step) of mechanically treating at a low temperature of less than 110 deg. C, for example, 40 to 100 deg. C, in a suitable mixer, but the present invention is not limited thereto.

The rubber composition for tire treads according to the present invention having the composition as described above has high purity, low temperature characteristics, and excellent fuel efficiency, but uses styrene-butadiene rubber containing oil having environmentally friendly characteristics, thereby improving wear and fuel efficiency of the rubber composition. Improve the flexibility and processability of the rubber by using an environmentally friendly oil containing less than 10mg / kg PAH as a softener, and as a result, the adjustment stability, wear performance, fuel economy performance and braking performance of the rubber composition is improved, By combining the filler and vulcanization accelerator in the optimum ratio, the wear performance is further improved, and by using the vulcanization accelerator with high boiling point, it prevents the occurrence of nitrosoamine, a carcinogenic substance, and is environmentally friendly and equivalent vulcanization compared to the existing rubber composition. Improved wear performance, braking performance and fuel economy along with characteristics It denotes a.

Accordingly, the rubber composition for tire tread according to the present invention is not limited to the tread (tread cap and tread base), but may be included in various rubber components constituting the tire. Said rubber components include sidewalls, sidewall inserts, apex, chafer, wire coat or inner liner.

In addition, the tire tread rubber composition may be used as a new tire tread rubber composition, or may be used as a retread tire tread rubber composition in which a new tread rubber is attached to a worn tread case.

According to another embodiment of the present invention provides a tire manufactured using the rubber tread rubber composition.

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

[Production Example: Production of Rubber Composition]

A rubber composition for tire treads according to Examples and Comparative Examples was prepared using the composition shown in Table 1 below. Preparation of the rubber composition for tire treads followed the conventional manufacturing method of the rubber composition for tire treads.

Item Reference Example Comparative Example 1 Example 1 Example 2 Styrene
Butadiene rubber E-SBR A ^① 110
(80) - - - E-SBR B ^② - 110
(80) - - E-SBR C ^③ - - 110
(80) 110
(80) Butadiene rubber BR ^④ 20 20 20 20 Filler Filler ^⑤ 70 70 70 75 Softener Oil A ^⑥ 8 - - - Oil B ^⑦ - 8 8 8 Vulcanization
accelerant Vulcanization accelerator A ^⑧ 1.1 1.1 1.1 1.3 Curing accelerator B ^⑨ 0.1 0.1 0.1 - Vulcanization accelerator C ^⑩ - - - 0.1 Other additives brimstone 1.8 1.8 1.8 1.8 Anti aging agent ^⑪ 2 2 2 2 Zinc oxide 2 2 2 2 Stearic acid 2 2 2 2

(Unit: parts by weight)

The values in parentheses of styrene butadiene rubber are the contents of styrene butadiene rubber except oil.

① E-SBR A: Emulsion polymerized styrene butadiene rubber with 24% by weight of styrene, 18% by weight of vinyl in butadiene and a glass transition temperature of -37 to -34 ℃, containing A # 2 oil

② E-SBR B: Emulsion-polymerized styrene butadiene rubber with styrene content of 24 wt%, vinyl content of butadiene 18 wt% and glass transition temperature of -58 to -49 ℃, containing TDAE (Treated distillate aromatic extract) oil

③ E-SBR C: Emulsion-polymerized styrene butadiene rubber with styrene content of 24% by weight, vinyl content in butadiene and 18% by weight of glass transition temperature, and -48 to -38 ℃, containing TRAE (Treated distillate aromatic extract) oil

④ BR: Butadiene rubber having a weight average molecular weight of 600,000, a molecular weight distribution of 3 to 5 and a glass transition temperature of -105 to -108 ° C, and does not contain extended oil.

⑤ Filler: Carbon black with nitrogen adsorption specific surface area (N ₂ SA) of 90 to 95 m ² / g

⑥ Oil A: Polycyclic aromatic hydrocarbon with PAH content of 10 mg / kg or more, kinematic viscosity of 91 (195 ° F), 40% by weight of aromatic components, 30% by weight of naphthenic components and 25% by weight of paraffinic components oil

⑦ Oil B: Low polycyclic aromatic hydro with a PAH content of less than 10 mg / kg, kinematic viscosity of 98 (210 ° F), 20% by weight aromatic, 32% by weight naphthenic and 48% by weight paraffinic Low PAHs Oil

⑧ Accelerator A: N-cyclohexyl-2-benzothiazole sulfenamide (CZ)

⑨ Acceleration accelerator B: tetramethyl thiuram disulfide (TMTD)

⑩ Vulcanization accelerator C: Zinc dibenzyldithiocarbamate (ZBEC)

⑪ Anti-aging agent: N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine (N- (1,3-Dimethybutyl) -N'-phenyl-p-phenylenediamine, 6PPD)

The properties of each emulsion polymerization styrene butadiene rubber of Table 1 were compared to Table 2 below.

Emulsion Polymerization Styrene Butadiene Rubber Type Styrene content
(weight%) Butadiene
Vinyl content (% by weight) Tg (占 폚) Types of Oil Contained Oil content (PHR) E-SBRA 24 18 -37 to -34 A # 2 ^① 37.5 E-SBR B 24 18 -58 to -49 TDAE ^② 37.5 E-SBR C 24 18 -48 to -38 TRAE ^③ 37.5

PHR Co., Ltd. means parts by weight of oil with respect to 100 parts by weight of the rubber component constituting the emulsion polymerization styrene butadiene rubber.

① aromatic oil

② Oil containing PAH content less than 10 mg / kg, kinematic viscosity 98 (210 ° F), 20 parts by weight of aromatic components, 32 parts by weight of naphthenic components and 48 parts by weight of paraffinic components.

③ Oil containing PAH content less than 10 mg / kg, kinematic viscosity 98 (210 ° F), 30 parts by weight of aromatic components, 26 parts by weight of naphthenic components and 44 parts by weight of paraffinic components.

In addition, the properties of each vulcanization accelerator in Table 1 were compared to Table 3 below.

Kinds line Amine Type Amines occur Boiling point (℃) Vulcanization accelerator A Sulfenamide Primary amine Not occurring - Vulcanization accelerator B Thiuram Disulfide Secondary amine Occur 60 to 80 Vulcanization accelerator C Dithiocarbamic acid Secondary amine Occur 300 or more

Toxic polycyclic aromatic (PCA) component included in the softener of Table 1 is shown in Table 4 below.

PCA Ingredients Chemical symbol PCA Ingredients Chemical symbol Benzo (a) pyrene BaP C ₂₀ H ₁₂ Benzo (b) fluoranthene BbFA C ₂₀ H ₁₂ Benzo (e) pyrene BeP C ₂₀ H ₁₂ Benzo (j) fluoranthene BjFA C ₂₀ H ₁₂ Benzo (a) anthracene BaA C ₁₈ H ₁₂ Benzo (k) fluoranthene BkFA C ₂₀ H ₁₂ Chrysene CHR C ₁₈ H ₁₂ Dibenzo (a, h) anthracene BbFA C ₂₀ H ₁₂

Experimental Example: Measurement of Physical Properties of Prepared Rubber Composition

After the rubber compositions for tire treads of the prepared examples and comparative examples were vulcanized at 150 ° C. for 30 minutes to prepare specimens, physical properties were measured in the following manner. The results are shown in Table 5 below.

1) Abrasion resistance index: Tested with a rambon abrasion tester, the larger the index, the better the wear resistance.

2) Braking and fuel efficiency: 0 ° C. tan δ and 60 ° C. tan δ were measured by RDS (Rheometrics Dynamic Spectrometer) by 0.5% strain, 10 Hz, temperature change (Temp. Sweep). 0 ° C tan δ indicates the braking performance. The larger the exponent value, the better the braking performance. The 60 ° C tan δ indicates the rotational resistance performance. The lower the index value, the better the fuel efficiency.

3) Vulcanization time: The vulcanization time t90 of the rubber composition was measured at 160 ° C using RDS. The larger t90 (min), the longer the vulcanization time of the rubber, and the smaller the shorter the vulcanization time.

Item Reference Example Comparative Example 1 Example 1 Example 2 Fuel efficiency 100 105 101 101 Braking characteristic 100 98 101 103 Wear resistance 100 96 96 101 Cure time 8.3 8.6 9.4 8.5

Distillate Aromatic Extract (DAE) oil contains oil with a PAH content of 10 mg / kg or more, kinematic viscosity of 91 (210 ° F), 40% by weight aromatic, 35% by weight naphthenic and 25% paraffinic to be. The DAE oil and the TDAE oil have different glass transition temperatures (Tg) due to the difference between the aromatic component, the naphthenic component, and the paraffin component, and as a result, exhibit different performances in the rubber composition. TDAE oil has a lower glass transition temperature than DAE oil, which is superior to DAE oil in terms of abrasion performance and fuel efficiency, but in terms of braking performance, it is disadvantageous as can be seen from the test results of Reference Example and Comparative Example 1 in Table 5 above. The results are shown. In order to compensate for the braking performance disadvantage while utilizing the advantages of the TDAE oil, the present invention simultaneously improved braking performance and fuel efficiency by using E-SBR C containing TRAE oil having a similar glass transition temperature with DAE oil. This is well shown in the performance test results of Comparative Example 1 and Example 1 of Table 5.

In addition, referring to Table 5, when the eco-friendly vulcanization accelerator C was applied to replace the vulcanization accelerator B generating the carcinogenic substance used in Comparative Example 1, the carcinogenic substance was not generated, but the vulcanization time increased at the same content ( See Example 1). On the other hand, by increasing the content of the vulcanization accelerator A including the primary amine compared to the existing one, it was confirmed in the performance test results of Example 2 that the equivalent cure time of Reference Example 1 without the occurrence of carcinogenic substances.

In the present invention, the tire tread rubber composition which can simultaneously improve the environment-friendly fuel efficiency, braking performance and abrasion resistance through the use of styrene butadiene rubber containing eco-friendly oil, the application of the optimum ratio of the vulcanization accelerator and the use of the eco-friendly vulcanization accelerator. Can be obtained.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (9)

75 to 82 parts by weight of an emulsion polymerization styrene butadiene rubber,
18 to 25 parts by weight of butadiene rubber,
5 to 11 parts by weight of softener,
63 to 79 parts by weight of a filler, and
Contains 0.1 to 1.9 parts by weight of vulcanization accelerator,
The emulsion-polymerized styrene butadiene rubber has a polycyclic aromatic hydrocarbon content of less than 10 mg / kg, a kinematic viscosity of 95 (210 ° F.) or more, 25 to 35 parts by weight of an aromatic component, and 21 to 31 parts by weight of a naphthenic component. And an oil comprising from 39 to 47 parts by weight of a paraffinic component,
The vulcanization accelerator is a rubber composition for a tire tread containing a dithiocarbamic acid and sulfenamide-based vulcanization accelerator having a breaking point of 300 ℃ or more in a weight ratio of 1: 1 to 1:20. The method of claim 1,
The emulsion-polymerized styrene butadiene rubber has a styrene content of 20 to 28% by weight, a vinyl content of butadiene of 15% by weight or more, and a glass transition temperature of -48 to -38 ° C. The method of claim 1,
The said emulsion-polymerized styrene butadiene rubber is a rubber composition for tire treads containing 25-60 weight part of said oil with respect to 100 weight part of rubbery components which comprise an emulsion polymerization styrene butadiene rubber. The method of claim 1,
The butadiene rubber has a weight average molecular weight of 600,000 or more, a molecular weight distribution of 3 to 5, the glass transition temperature is -105 to -108 ℃ rubber composition for tire tread. The method of claim 1,
The softener has a polycyclic aromatic hydrocarbon content of less than 10 mg / kg, kinematic viscosity of 95 (210 ° F) or more, 15 to 25% by weight of the aromatic component in the softener, 27 to 37% by weight of the naphthenic component, And paraffin-based component is 38 to 58% by weight of the rubber composition for tire tread. The method of claim 1,
The filler is a rubber composition for a tire tread having a nitrogen adsorption specific surface area (N ₂ SA) of 90 to 95 m ₂ / g. The method of claim 1,
The dithiocarbamic acid-based vulcanization accelerator comprises dibenzyldithiocarbamic acid zinc, tetrabenzyldithiocarbamic acid zinc, 1,6-bis (N, N-dibenzylthiocarbamodithio) hexane and mixtures thereof. Rubber composition for a tire tread having a boiling point of 300 ° C. or higher with any one selected from the group. delete A tire produced by using the rubber composition for a tire tread according to claim 1.