KR20120007716A

KR20120007716A - Tire

Info

Publication number: KR20120007716A
Application number: KR1020100068379A
Authority: KR
Inventors: 김병립
Original assignee: 한국타이어 주식회사
Priority date: 2010-07-15
Filing date: 2010-07-15
Publication date: 2012-01-25
Also published as: CN102336120A; CN102336120B; KR101290721B1

Abstract

The present invention includes an upper cap tread portion which is in direct contact with a road surface, and includes an upper cap tread portion including a first silica, and an inner cap tread portion located on an inner surface of the upper cap tread portion, and includes an lower cap tread portion including a second silica. The particle diameter provides a tire that is smaller than the average particle diameter of the second silica.
The tire may contain a large amount of silica and efficiently mix silica, and absorb the water on the wet road at high speed, and then quickly discharge it, thereby improving the insufficient grip performance on the wet road.

Description

Tires {TIRE}

The present invention relates to a tire having excellent grip performance on wet road surfaces.

The biggest problem for drivers in rainy weather is the deterioration of grip performance on wet road surfaces and the drainage of tires. For the general drivers, the above problems are important problems in rainy weather, but they require attention while driving, but are becoming more serious in motor racing races that drive at high speeds.

In order to improve the drainage side and grip performance of the tire on the wet road, conventionally, a rubber compound is used to increase the content of silica. However, in the case of increasing the content of silica, there is a problem of poor dispersion due to the nature of the silica itself.

In addition, in the case of racing tires, a method of adjusting air pressure is applied so that a large amount of air pressure is applied to the tire at the beginning of a race so that a drainage line is clearly formed and a larger amount of drainage can be made. We have tried to change the pattern of wealth. However, when a large amount of air pressure is applied to the tire at the beginning of the race, the air expands due to the heat inside the tire when the vehicle is running, which can cause a large strain on the tire, and there is a limit to the change of the pattern.

In addition, driving on wet roads also has the characteristics of being vulnerable to heat generation, so it is difficult to improve driving power and improve grip performance by improving drainage.

An object of the present invention is to include a large amount of silica while efficiently mixing the silica, by absorbing the water on the wet road at high speed, and then quickly discharged, it is possible to improve the insufficient grip performance on the wet road surface To provide tires.

In order to achieve the above object, the present invention includes an upper cap tread portion which is in contact with the road surface and includes a first silica, and an inner cap tread portion which is positioned on an inner surface of the upper cap tread portion and includes a second silica. The average particle diameter of the first silica provides a tire that is smaller than the average particle diameter of the second silica.

The first silica may have an average particle diameter of 0.5 μm or more and less than 4.0 μm, and the second silica may have an average particle diameter of 4.0 μm or more and 9.0 μm or less.

Wherein the first silica has N ₂ SA is specific surface area of 400m ² / g more than 980m ² / g or less, wherein the second silica has a surface area N ₂ SA may be less than 80m ² / g more than 400m ² / g.

The upper layer capped portion may include 10 to 90 parts by weight of the first silica, based on 100 parts by weight of the raw material rubber, and the lower layer capped portion may include 10 to 90 parts by weight of the second silica based on 100 parts by weight of the raw rubber. have.

Any one selected from the group consisting of the upper layer cap tread portion, the lower layer cap tread portion, and a combination thereof further includes 10 to 90 parts by weight of carbon black based on 100 parts by weight of the raw material rubber, wherein the carbon black has a DBP oil absorption amount. 200 to 740 ml / 100 g, and a BET specific surface area of 480 to 990 m ² / l.

A weight ratio of the upper cap tread portion and the lower cap tread portion may be 40:60 to 50:50.

The tire tread may further include an under tread part located on an inner surface of the lower cap tread part.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement 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.

1 is a cross-sectional view of main parts of a tire according to an embodiment of the present invention.

Referring to FIG. 1, the tire 1 includes a tread portion 10, a side wall portion 20, a belt portion 30, a carcass portion 40, and an inner liner portion 50. The side wall portion 20, the belt portion 30, the carcass portion 40 and the inner liner portion 50 may be applied to any of those commonly used in the tire field to which the present invention belongs, detailed description herein Is omitted. In addition, the tire 1 is not limited to the above structure, and the structure of all tires known in the art may be applied.

The tread portion 10 is a portion in direct contact with the ground and transmits the driving force and the braking force of the vehicle to the road surface. The sight wall 20 serves as an intermediate position for protecting the carcass portion 40 from external impact and transmitting the movement of the steering wheel to the tread portion 10 via a bead (not shown). The belt part 30 is composed of a steel belt for adjusting the performance of road surface traction and handling, and a reinforcing cap ply and a belt cushion for preventing separation between the steel belt layers. It may include.

The carcass portion 40 serves as a skeleton forming a skeleton of the tire and supports the load added from the outside by maintaining the air pressure together with the inner liner 50. The inner liner 50 functions to maintain the air pressure inside the tire.

On the other hand, the tread portion 10 is in direct contact with the road surface, the upper layer cap tread portion 11 including the first silica, the inner layer of the upper cap tread portion 11, the lower layer containing the second silica The cap tread portion 12 and, optionally, the under tread portion 13 positioned on the inner surface of the lower cap tread portion 12 may be included. The undertread portion 13 may be used as long as it is commonly used in the tire field to which the present invention belongs, and a detailed description thereof will be omitted.

The average particle diameter of the first silica is smaller than the average particle diameter of the second silica. As the upper cap tread portion 11 and the lower cap tread portion 12 include silica having different average particle diameters, the upper cap tread portion 11 absorbs water from the road surface at a higher rate than the conventional cap tread portion and discharges at a high rate. In addition, due to the friction between the silica having different average particle diameters present in the upper cap tread portion 11 and the lower cap tread portion 12 can improve the insufficient grip performance on the wet road surface.

That is, the first silica included in the upper cap tread portion 11 which is in direct contact with the road surface has an average particle diameter smaller than that of the second silica in order to absorb a larger amount of water within the same time. Silica has a larger average particle diameter than the first silica in order to easily discharge the absorbed water. In addition, it is possible to discharge the water quickly due to the pressure difference caused by the friction between the silica of different sizes.

Specifically, the first silica has an average particle diameter of 0.5um or more and less than 4.0um, preferably 1.0 to 2.0um, the first silica is N ₂ SA surface area of 400m ² / g or more and 980m ² / g or less , Preferably 580 to 780 m ² / g. If the average particle diameter or the N ₂ SA surface area of the first silica is within the above range, a larger amount of water may be absorbed within the same time.

The second silica has an average particle diameter of 4.0um or more and 9.0um or less, preferably 4.5 to 5.5um, and the second silica has an N ₂ SA surface area of 80m ² / g or more and less than 400m ² / g, preferably 110 to 310 m ² / g. When the average particle diameter or the N ₂ SA surface area of the second silica is within the above range, water absorbed by the first silica may be more easily discharged.

In addition, the weight ratio of the upper cap tread portion 11 and the lower cap tread portion 12 may be 40:60 to 50:50. When the weight ratio of the upper cap tread portion 11 and the lower cap tread portion 12 is within the above range, the grip performance on the wet road surface may be further improved due to friction between the first silica and the second silica. .

The upper layer cap tread portion 11 may include 10 to 90 parts by weight of the first silica, preferably 30 to 60 parts by weight, based on 100 parts by weight of the raw material rubber, and the lower layer cap tread portion 12 is a raw material rubber 10 to 90 parts by weight of the second silica, preferably 30 to 60 parts by weight, based on 100 parts by weight. When the content of the first silica and the second silica in the upper cap tread portion 11 and the lower cap tread portion 12 exceeds 90 parts by weight, respectively, it is difficult to mix due to the excess silica content. In case of less than 10 parts by weight, the effect that can be obtained by adding silica having different particle diameters may be insignificant. In addition, the tire 1 separates the cap tread portion into two layers, and includes silica in the upper cap tread portion 11 and the lower cap tread portion 12, respectively, so that a higher content of silica is achieved. Incorporation can be achieved while efficient formulation is achieved.

The raw rubber may be any one selected from the group consisting of natural rubber, synthetic rubber, and combinations thereof.

The natural rubber may be general natural rubber or modified natural rubber.

The general natural rubber may be used as long as it is known as natural rubber, and the origin and the like are not limited. The natural rubber contains cis-1,4-polyisoprene as a main agent, but may also include trans-1,4-polyisoprene depending on the required properties. Therefore, the natural rubber includes, in addition to the natural rubber containing cis-1,4-polyisoprene as a main agent, for example, a natural containing trans-1,4-isoprene as a main agent such as a balata, which is a kind of rubber of South American sapotagua. Rubber may also be included.

The modified natural rubber means a modified or refined general natural rubber. For example, examples of the modified natural rubber include epoxidized natural rubber (ENR), deproteinized natural rubber (DPNR), and hydrogenated natural rubber.

Synthetic rubber is styrene butadiene rubber (SBR), modified styrene butadiene rubber, butadiene rubber (BR), modified butadiene rubber, chloro sulfonated polyethylene rubber, epichlorohydrin rubber, fluorine rubber, silicone rubber, nitrile rubber, hydrogenated Nitrile Rubber, Nitrile Butadiene Rubber (NBR), Modified Nitrile Butadiene Rubber, Chlorinated Polyethylene Rubber, Styrene Ethylene Butylene Styrene (SEBS) Rubber, Ethylene Propylene Rubber, Ethylene Propylene Diene (EPDM) Rubber, Hypalon Rubber, Chloroprene Rubber, Ethylene vinyl acetate rubber, acrylic rubber, hydrin rubber, vinyl benzyl chloride styrene butadiene rubber, bromo methyl styrene butyl rubber, maleic acid styrene butadiene rubber, carboxylic acid styrene butadiene rubber, epoxy isoprene rubber, maleic acid ethylene propylene rubber, carboxylic acid Nitrile Butadiene High It may be a p-methyl styrene (brominated polyisobutyl isoprene-co-paramethyl styrene, BIMS), and one selected from the group consisting of -, bromo mineyi suited polyisobutyl isoprene-co.

In particular, the raw material rubber is polyisoprene rubber, polybutadiene rubber, conjugated diene aromatic vinyl copolymer, nitrile conjugated diene copolymer, hydrogenated nitrile butadiene rubber (NBR), hydrogenated styrene butadiene rubber (SBR), olefin rubber, maleic acid It may include any one selected from the group consisting of modified ethylene-propylene rubber, butyl rubber, copolymer of isobutylene and aromatic vinyl or diene monomer, acrylic rubber, ionomer, halogenated rubber and chloroprene rubber.

Any one selected from the group consisting of the upper cap tread portion 11, the lower cap tread portion 12, and a combination thereof may further include 10 to 90 parts by weight of carbon black based on 100 parts by weight of the raw material rubber. have. If the content of the carbon black is less than 10 parts by weight, the improvement of reinforcement performance by the carbon black as a filler may be insignificant, and if it exceeds 90 parts by weight, the processability of the rubber composition may be deteriorated.

The carbon black may have a DBP oil absorption of 200 to 740 ml / 100 g, and a BET specific surface area of 480 to 990 m ² / l. Since the upper cap tread portion 11 or the lower cap tread portion 12 includes the first silica and the second silica, respectively, when the DBP oil absorption of the carbon black exceeds 740 ml / 100 g, the workability of the rubber composition is increased. When the carbon black is less than 200ml / 100g, the reinforcement performance by the carbon black filler may be improved, and when the BET specific surface area of the carbon black exceeds 990m ² / l, the processability of the rubber composition for a tire may be deteriorated. If less than 480m ² / l, the improvement of reinforcement performance by carbon black as a filler may be insignificant.

The tire 1 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 is preferably a racing tire. In addition, the tire may be a radial tire or a bias tire, and is preferably a radial tire.

Since the method of manufacturing the tire 1 can be applied to any method conventionally used for the production of tires, detailed description thereof will be omitted.

However, the upper cap tread portion 11 or the lower cap tread portion 12 may be manufactured by vulcanizing a rubber tread rubber composition prepared by mixing the raw material rubber with the first silica or the second silica. In this case, the tire tread rubber composition may further include various additives such as a vulcanizing agent, a vulcanization accelerator, a vulcanization accelerator, a coupling agent, an anti-aging agent or a softener. The various additives can be used as long as it is commonly used in the field of the present invention, the content thereof is not particularly limited, depending on the compounding ratio used in the conventional tire tread rubber composition.

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

The sulfur-based vulcanizing agents include inorganic vulcanizing agents such as powdered sulfur (S), insoluble sulfur (S), precipitated sulfur (S) and colloidal sulfur, tetramethylthiuram disulfide (TMTD) and tetraethyl. Organic vulcanizing agents such as tetraethyltriuram disulfide (TETD) and dithiodimorpholine can be used. Specifically, as the sulfur vulcanizing agent, a vulcanizing agent which produces elemental sulfur or sulfur, for example, amine disulfide, polymer sulfur, or the like can be used.

The vulcanizing agent is preferably 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 that the raw material rubber is less sensitive to heat and chemically stable.

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

The vulcanization accelerators include sulfenamide, thiazole, thiuram, thiourea, guanidine, dithiocarbamic acid, aldehyde-amine, aldehyde-ammonia, imidazoline, xanthate and their Any one selected from the group consisting of a combination can be used. Sulfenamide based vulcanization accelerators such as N-cyclohexyl-2-benzothiazylsulfenamide (CBS) or N-tert-butyl-2-benzothiazylsulfenamide (TBBS), 2-mercaptobenzothiazole (MBT) ) Or thiazole vulcanization accelerators such as dibenzothiazyl disulfide (MBTS), thiuram vulcanization accelerators such as tetramethylthiuram disulfide (TMTD), and guanidine vulcanization accelerators such as diphenylguanidine (DPG).

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 and rubber properties by promoting the vulcanization rate.

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

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

In particular, the zinc oxide and the stearic acid may be used together as the vulcanization accelerator, in which case the zinc oxide is dissolved in the stearic acid to form an effective complex with the vulcanization accelerator, thereby releasing advantageous sulfur during the vulcanization reaction. It facilitates the crosslinking reaction of the rubber.

When using the zinc oxide and the stearic acid together may be used in 1 to 5 parts by weight and 0.5 to 3 parts by weight with respect to 100 parts by weight of the raw material rubber, respectively, to serve as a suitable vulcanization accelerator.

In order to improve the compatibility of the rubber with the first or second silica, a coupling agent may be further used. Examples of the coupling agent include a sulfide silane compound, a mercapto silane compound, a vinyl silane compound, an amino silane compound, a glycidoxy silane compound, a nitro silane compound, a chloro silane compound, a methacryl silane compound, and a combination thereof. Any one selected from the group consisting of can be used, and sulfide-based silane compounds can be preferably used.

The sulfide-based silane compound may be bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (4-triethoxysilylbutyl) tetrasulfide, bis (3-tri Methoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, bis (4-trimethoxysilylbutyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (2 -Triethoxysilylethyl) trisulfide, bis (4-triethoxysilylbutyl) trisulfide, bis (3-trimethoxysilylpropyl) trisulfide, bis (2-trimethoxysilylethyl) trisulfide, bis (4-trimethoxysilylbutyl) trisulfide, bis (3-triethoxysilylpropyl) disulfide, bis (2-triethoxysilylethyl) disulfide, bis (4-triethoxysilylbutyl) disulfide, bis ( 3-trimethoxysilylpropyl) disulfide, bis (2-trimethoxy Sisylethyl) disulfide, bis (4-trimethoxysilylbutyl) disulfide, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, 3-triethoxysilylpropyl-N, N-dimethyl Thiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 2-trimethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilyl Propylbenzothiazolyl tetrasulfide, 3-triethoxysilylpropylbenzothiazole tetrasulfide, 3-trimethoxysilylpropylmethacrylate monosulfide, 3-trimethoxysilylpropylmethacrylate monosulfide and combinations thereof It may be any one selected from the group consisting of.

The mercapto silane compound is 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane and combinations thereof It may be any one selected from the group consisting of. The vinyl silane compound may be any one selected from the group consisting of ethoxysilane, vinyltrimethoxysilane, and combinations thereof. The amino silane compound is 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropyltri It may be any one selected from the group consisting of methoxysilane and combinations thereof.

The glycidoxy silane compounds include γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and γ-glycidoxypropylmethyldimethoxysilane And combinations thereof may be any one selected from the group consisting of. The nitro silane compound may be any one selected from the group consisting of 3-nitropropyltrimethoxysilane, 3-nitropropyltriethoxysilane, and combinations thereof. The chloro-based silane compound is selected from the group consisting of 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 2-chloroethyltrimethoxysilane, 2-chloroethyltriethoxysilane, and combinations thereof. It can be any one.

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

The coupling agent may be included in an amount of 1 to 20 parts by weight based on 100 parts by weight of the raw material rubber to improve dispersibility of the silica. When the content of the coupling agent is less than 1 part by weight, the improvement of dispersibility of silica may be insufficient, resulting in deterioration of the processability of the rubber or low fuel consumption performance. When the content of the coupling agent is more than 20 parts by weight, the interaction between silica and rubber is so strong that the fuel efficiency is low. May be good but the braking performance may be very poor.

The softener is added to the rubber composition to impart plasticity to the rubber to facilitate processing or to lower the hardness of the vulcanized rubber, and refers to oils and other materials used in rubber compounding or rubber production. The softener may be any one selected from the group consisting of petroleum oil, vegetable oil and combinations thereof, but the present invention is not limited thereto.

The petroleum oil may be any one selected from the group consisting of paraffinic oil, naphthenic oil, aromatic oil, and combinations 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. N-1, N-2, N-3, etc. of the corporation | Co., Ltd. are mentioned, As a representative example of the said aromatic oil, A-2, A-3, etc. of Michang Oil Corporation are mentioned.

However, it is known that cancer is more likely to occur when the content of polycyclic aromatic hydrocarbons (hereinafter referred to as "PAHs") included in the aromatic oils is 3% by weight or more with the recent increase of environmental awareness. , TDAE (treated distillate aromatic extract) oil, mild extraction solvate (MES) oil, residual aromatic extract (RAE) oil or heavy naphthenic oil can be preferably used.

In particular, the oil used as the softener has a total content of PAHs component of 3% by weight or less, a kinematic viscosity of 95 ° C or more (210 ° F SUS), an aromatic component in the softener of 15 to 25% by weight, naphthenic TDAE oils with 27 to 37% by weight and 38 to 58% by weight of paraffinic components can be preferably used.

The TDAE oil is advantageous in terms of environmental factors such as the low temperature characteristics of the tire tread including the TDAE oil, fuel efficiency, and the likelihood of causing cancer of PAHs.

The softening agent is preferably used in an amount of 0 to 150 parts by weight based on 100 parts by weight of the raw material rubber, in terms of improving the processability of the raw material rubber.

The anti-aging agent is an additive used to stop the chain reaction in which the tire is automatically oxidized by oxygen. As the anti-aging agent, any one selected from the group consisting of amine-based, phenol-based, quinoline-based, imidazole-based, carbamic acid metal salts, waxes, and combinations thereof may be appropriately selected.

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

The anti-aging agent has a high solubility in rubber in addition to the anti-aging action, is low in volatility, inert to rubber, and does not inhibit vulcanization. It may be included in parts by weight.

Tire according to an embodiment of the present invention can be efficiently blended silica containing a large amount of silica, absorbs the water on the wet road at high speed, and then quickly discharged, insufficient grip performance on the wet road surface Can improve.

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

[Production Example: Production of Tire]

Using a composition as shown in Table 1 below to prepare a tire including an upper cap tread portion and a lower cap tread portion in a 50:50 weight ratio. The configuration of the tire except the upper cap tread portion and the lower cap tread portion was in accordance with a conventional tire manufacturing method. However, in the case of Comparative Examples 1 and 2, the cap tread portion was formed in a single layer.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 Upper Cap Tread Raw Material Rubber ⁽¹⁾
(Rubber / oil) 218.25
(100 /
118.25) - 218.25
(100 /
118.25) 218.25
(100 /
118.25) 218.25
(100 /
118.25) 218.25
(100 /
118.25) Carbon Black ⁽²⁾ 50.0 - 50.0 50.0 50.0 50.0 First Silica ⁽³⁾ 10.0 - 10.0 30.0 60.0 90.0 Zinc oxide 3.0 - 3.0 3.0 3.0 3.0 Stearic acid 1.0 - 1.0 1.0 1.0 1.0 brimstone 1.0 - 1.0 1.0 1.0 1.0 Primary vulcanization accelerators ⁽ 2006.01 ⁾ 2.5 - 2.5 2.5 2.5 2.5 Second Vulcanization Accelerator ⁽⁶⁾ 2.0 - 2.0 2.0 2.0 2.0 Underlayer cap
Tread section Raw Material Rubber ⁽¹⁾
(Rubber / oil) - 218.25
(100 /
118.25) 218.25
(100 /
118.25) 218.25
(100 /
118.25) 218.25
(100 /
118.25) 218.25
(100 /
118.25) Carbon Black ⁽²⁾ - 50.0 50.0 50.0 50.0 50.0 Second Silica ⁽⁴⁾ - 10.0 10.0 30.0 60.0 90.0 Zinc oxide - 3.0 3.0 3.0 3.0 3.0 Stearic acid - 1.0 1.0 1.0 1.0 1.0 brimstone - 1.0 1.0 1.0 1.0 1.0 Primary vulcanization accelerators ⁽ 2006.01 ⁾ - 2.5 2.5 2.5 2.5 2.5 Second Vulcanization Accelerator ⁽⁶⁾ - 2.0 2.0 2.0 2.0 2.0

(Unit: parts by weight)

(1) Raw material rubber: natural rubber / TDAE oil

(2) Carbon Black: Ultrafine Carbon Black (DBP Oil Absorption 360ml / 100g, BET Specific Surface Area 800m2 / l)

(3) First silica: Silica having an average particle diameter of 1.5 um and an N ₂ SA surface area of 680 m ² / g

(4) Second Silica: Silica having an average particle diameter of 5.0 um and N ₂ SA surface area of 210 m ² / g

(5) First vulcanization accelerator: N-cyclohexyl-2-benzothiazylsulfenamide (CBS)

(6) Second Vulcanization Accelerator: Diphenylguanidine (DPG)

Experimental Example: Measurement of Physical Properties of Manufactured Tires

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

Mooney viscosity in Table 2 (ML1 + 4 (125 ℃)) was measured by SMS ASTM standard D1646. Mooney viscosity is a value indicating the viscosity of the unvulcanized rubber, the lower the value indicates that the workability of the unvulcanized rubber is excellent.

Hardness was measured according to DIN 53505. Hardness indicates steering stability. The higher the value, the better the steering stability.

300% Modulus (Modulus) is the tensile strength at 300% elongation, measured according to the ISO 37 standard, the higher the value shows excellent strength.

Elongation was measured by the method of expressing the strain value in% until the test piece breaks in a tensile tester. The greater the elongation, the better the elongation.

Viscoelasticity was measured from -60 ° C. to 80 ° C. at 10 Hz frequency at 0.1% strain using Rheometrics Dynamic Spectrometer (RDS). At this time, the higher the 0 ° C tanδ value, the better the braking performance on the wet road surface, and the lower the 60 ° C tanδ value, the lower the rolling resistance.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 Mooney viscosity 62 61 64 67 72 74 Hardness
(Shore A) 60 59 62 65 67 68 300% modulus
(Mpa) 40.5 40.7 42.1 51.2 57.9 59.1 Elongation (%) - - 810 757 731 725 0 ℃ tanδ 0.154 0.161 0.182 0.199 0.251 0.361 60 ℃ tanδ 0.101 0.107 0.117 0.131 0.144 0.172

Referring to Table 2, the tires manufactured in Examples 1 to 4 have increased 0 ° C. tanδ, which indicates the performance on wet roads, compared to the tires manufactured in Comparative Examples 1 and 2, and thus, the improved performance on wet roads can be expected. In addition, 60 ° C. tan δ also tends to increase dramatically, and the grip performance can be expected to improve even under conditions of damping the road surface.

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.

1: tire
10: tread section
11: upper layer cap tread portion 12: lower layer cap tread portion
13: under tread
20: side wall portion 30: belt portion
40: carcass part 50: inner liner part

Claims

An upper cap tread portion in contact with the road surface and including first silica; and
Located on the inner surface of the upper cap tread portion, and includes a lower cap tread portion including a second silica,
The tire of which the average particle diameter of the first silica is smaller than the average particle diameter of the second silica.

The method of claim 1,
The first silica has an average particle diameter of 0.5um or more and less than 4.0um,
The second silica has an average particle diameter of 4.0um or more and 9.0um or less.

The method of claim 2,
The first silica has a N ₂ SA surface area of 400m ² / g or more and 980m ² / g,
The second silica has a N ₂ SA surface area of 80m ² / g or more and less than 400m ² / g.

The method of claim 1,
The upper layer cap tread portion comprises 10 to 90 parts by weight of the first silica with respect to 100 parts by weight of the raw material rubber,
The lower layer cap tread portion of the tire containing 10 to 90 parts by weight of the second silica with respect to 100 parts by weight of the raw rubber.

The method of claim 1,
Any one selected from the group consisting of the upper layer cap tread portion, the lower layer cap tread portion and a combination thereof further includes 10 to 90 parts by weight of carbon black based on 100 parts by weight of the raw material rubber,
The carbon black has a DBP oil absorption of 200 to 740ml / 100g, the BET specific surface area is 480 to 990m ² / l tire.

The method of claim 1,
The weight ratio of the upper layer cap tread portion and the lower layer cap tread portion is 40:60 to 50:50.

The method of claim 1,
The tire tread further comprises an under tread portion located on an inner surface of the lower cap tread portion.