KR102597055B1 - Rubber composition for tire tread and Tire comprising the rubber composition - Google Patents

Abstract

Butadiene rubber and styrene-butadiene rubber as raw material rubber; Silica as filler; A tire tread rubber composition comprising: and resin;
The tire tread rubber composition is disclosed, wherein the softening point of the resin is 80°C to 150°C, and the tire tread rubber obtained by vulcanizing the tire tread rubber composition is in a glass transition state in the entire range of -40°C to -3°C. do.

Description

Tire tread rubber composition and tire comprising the same {Rubber composition for tire tread and Tire comprising the rubber composition}

It relates to a tire tread rubber composition and a tire containing the same.

Car tires are objects that support heavy loads and rotate at high speeds. The tread, which has the greatest impact on the durability of a tire, is in contact with the ground and has a great impact on the driving performance of the tire.

The characteristics that tire tread rubber must have include steering stability, ride comfort, fuel efficiency, snow performance, abrasion resistance, braking performance, and durability.

One aspect is to provide a tread rubber composition with low braking performance sensitivity to temperature and improved braking performance for all seasons.

Another aspect is to provide a tire made from the rubber composition.

According to one aspect,

Butadiene rubber and styrene-butadiene rubber as raw material rubber;

Silica as filler; and

A tire tread rubber composition comprising resin,

The softening point of the resin is 80°C to 150°C,

The tire tread rubber obtained by vulcanizing the tire tread rubber composition is in a glass transition state in the entire range of -40°C to -3°C.

A tire tread rubber composition is provided.

According to one other aspect,

A tire made from the tire tread rubber composition is provided.

Tires using the tire tread rubber composition according to one embodiment of the present invention exhibit improved dry braking performance and wet braking performance, and the sensitivity of braking performance to temperature is relatively reduced.

Figure 1 is a diagram schematically showing the structure of a tire according to an embodiment.
Figure 2 is a graph showing tanδ values according to temperature of tread rubber according to one embodiment.
Figure 3 is a graph showing the dynamic modulus E' value according to temperature of the tread rubber according to one embodiment.

Hereinafter, the tire tread rubber composition and tire in one exemplary embodiment will be described in more detail.

The creative idea disclosed in this specification can be subjected to various transformations and can have various implementation examples, and specific implementation examples are described in detail in the detailed description and, if necessary, specific implementation examples are illustrated in the drawings. The effects and features of the creative ideas of this specification and methods for achieving them will become clear by referring to the implementation examples described in detail below along with the drawings. However, the creative ideas of the present specification are not limited to the implementation examples disclosed below and may be implemented in various forms.

In the following implementation examples, terms such as first and second are used not in a limiting sense but for the purpose of distinguishing one component from another component.

In the following embodiments, singular terms include plural terms unless the context clearly dictates otherwise.

In the following implementation examples, terms such as include or have mean that the features or components described in the specification exist, and do not preclude the possibility of adding one or more other features or components.

In cases where an embodiment can be implemented differently, a specific process sequence may be performed differently from the described sequence. For example, two processes described in succession may be performed substantially at the same time, or may be performed in an order opposite to that in which they are described.

Hereinafter, when necessary, embodiments of the present invention will be described in detail with reference to the accompanying drawings. When describing with reference to the drawings, identical or corresponding components will be assigned the same reference numerals and redundant description thereof will be omitted. Do this.

In the drawings, the sizes of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are shown arbitrarily for convenience of explanation, so the creative ideas disclosed in this specification are not necessarily limited to what is shown.

A tire tread rubber composition according to one embodiment includes butadiene rubber and styrene-butadiene rubber as raw rubber; Silica as filler; and resin; Here, the softening point of the resin may be 80°C to 150°C. The Tg of the resin may be -29°C to 100°C.

Meanwhile, tire tread rubber obtained by vulcanizing the tire tread rubber composition may be in a glass transition state within the entire range of -40°C to -3°C. For example, tire tread rubber obtained by vulcanizing the tire tread rubber composition may be in a glass transition state within the entire range of -30°C to -3°C.

In other words, tire tread rubber obtained by vulcanizing the tire tread rubber composition can be said to have a glass transition temperature, Tg, in the entire range of -40°C to -3°C. For example, tire tread rubber obtained by vulcanizing the tire tread rubber composition may have a glass transition temperature, Tg, in the entire range of -30°C to -3°C. Therefore, for example, the physical properties are different from rubber, which has a Tg of -29°C and a single point.

According to one embodiment of the present invention, the styrene butadiene rubber may include solution polymerized styrene butadiene rubber (SSBR). For example, the styrene butadiene rubber may include two different types of solution polymerized styrene butadiene rubber (SSBR).

According to one embodiment of the present invention, the styrenebutadiene rubber is solution polymerized styrenebutadiene rubber (SSBR) A having a styrene:vinyl ratio of 30:70 to 70:30; and solution polymerized styrenebutadiene rubber (SSBR) B having a styrene:vinyl ratio of 10:30 to 30:10. The styrene:vinyl ratio refers to the ratio of the number of styrene functional groups and the number of vinyl functional groups in the polymer chain.

For example, the styrene:vinyl ratio of solution polymerized styrenebutadiene rubber (SSBR) A may be 30:65 to 45:30. For example, the styrene:vinyl ratio of solution polymerized styrenebutadiene rubber (SSBR) A may be 30:45 to 35:55.

For example, the styrene:vinyl ratio of solution polymerized styrenebutadiene rubber (SSBR) B may be 10:30 to 20:12. For example, the styrene:vinyl ratio of solution polymerized styrenebutadiene rubber (SSBR) B may be 12:25 to 15:15.

When the ratio of styrene:vinyl in the solution-polymerized styrene-butadiene rubber (SSBR) B and the solution-polymerized styrene-butadiene rubber (SSBR) A is within the above range, the Tg of the vulcanized tread rubber composition has the above range.

According to one embodiment of the present invention, the raw rubber of the tire tread composition may be composed of butadiene rubber and the styrene-butadiene rubber. The butadiene rubber may not be a high-cis butadiene rubber, but may be a general butadiene rubber with a Tg of about -100°C.

Meanwhile, the tire tread composition may further include at least one raw rubber selected from, for example, isoprene-containing styrene butadiene rubber, nitrile-containing styrene butadiene rubber, neoprene rubber, chlorobutyl rubber, and bromobutyl rubber.

Additionally, the rubber composition may further include natural rubber in addition to synthetic rubber as the raw rubber. The natural rubber may be general natural rubber or modified natural rubber.

The general natural rubber can be used as long as it is known as natural rubber, and its place of origin is not limited. The natural rubber mainly contains cis-1,4-polyisoprene, but may also contain trans-1,4-polyisoprene depending on required properties. Accordingly, the above-mentioned natural rubber includes, in addition to natural rubber containing cis-1,4-polyisoprene as a main body, natural rubber containing trans-1,4-isoprene as a main body, such as balata, a type of rubber of the Sapotaceae family from South America. It may also contain rubber.

The modified natural rubber refers to the general natural rubber that has been modified or refined. For example, the modified natural rubber includes epoxidized natural rubber (ENR), deproteinized natural rubber (DPNR), and hydrogenated natural rubber.

According to one embodiment of the present invention, the content of the solution polymerized styrene butadiene rubber (SSBR) B may be 1.5 to 2.8 times the content of the solution polymerized styrene butadiene rubber (SSBR) A.

For example, based on 100 parts by weight of raw rubber, the content of the solution polymerized styrene butadiene rubber (SSBR) A may be 15 to 30 parts by weight, and the content of the solution polymerized styrene butadiene rubber (SSBR) B may be 30 to 60 parts by weight. parts, and the content of the butadiene rubber may be 15 to 25 parts by weight.

In the raw rubber, the contents of solution-polymerized styrene-butadiene rubber (SSBR) A, solution-polymerized styrene-butadiene rubber (SSBR) B, and butadiene rubber must satisfy the above range for the Tg of the vulcanized tread rubber composition to have the above range.

According to one embodiment of the present invention, the rubber composition may further include a filler, for example, silica and/or carbon black. Preferably, the rubber composition may contain only silica as a filler.

Any commonly known silica can be used, for example, commercially available Z-175, HD-165GR, US7000GR or 9000GR.

According to one embodiment of the present invention, the content of silica may be 30 to 90 parts by weight based on 100 parts by weight of the raw rubber. When the silica content is within the above range, the physical properties of the tread rubber are optimal.

The silica may have a nitrogen surface area per gram (N ₂ SA) of 100 to 180 m ² /g and a CTAB (cetyl trimethyl ammonium bromide) adsorption specific surface area of 110 to 170 m ² /g. The present invention is not limited to this.

If the nitrogen adsorption specific surface area of the silica is less than 100 m ² /g, the reinforcement performance by silica as a filler may be disadvantageous, and if it exceeds 180 m ² /g, the processability of the rubber composition may be disadvantageous. In addition, if the CTAB adsorption specific surface area of the silica is less than 110 m ² /g, the reinforcement performance by silica as a filler may be disadvantageous, and if it exceeds 170 m ² /g, the processability of the rubber composition may be disadvantageous.

According to one embodiment of the present invention, the tread rubber composition may include silica and a coupling agent. The coupling agent may be used to improve dispersion of silica. Meanwhile, depending on the silica content, a coupling agent may not be included.

The coupling agent may be, for example, a silane coupling agent. The silane coupling agent is a coupling agent containing Si, and the silane coupling agent binds to the OH of silica to reduce the polarity of silica so that it mixes well with rubber. Any silane coupling agent can be used as long as it is commonly used in the field to which the present invention pertains.

According to one embodiment of the present invention, the content of the coupling agent may be 5 to 11 parts by weight based on 100 parts by weight of raw rubber. Considering the content of the raw rubber and the content of silica, when the content of the coupling agent is within the above range, the processing of the rubber composition is smooth and the physical properties of the crosslinked rubber are optimal.

The carbon black may have a nitrogen adsorption specific surface area per gram (N ₂ SA) of 30 to 300 m ² /g and a DBP (n-dibutyl phthalate) oil absorption of 60 to 180 cc/100 g, but according to the present invention This is not limited to this.

If the nitrogen adsorption specific surface area of the carbon black exceeds 300 m ² /g, the processability of the rubber composition for tires may be disadvantageous, and if it is less than 30 m ² /g, the reinforcement performance by carbon black as a filler may be disadvantageous. In addition, if the DBP oil absorption of the carbon black exceeds 180cc/100g, the processability of the rubber composition may be reduced, and if it is less than 60cc/100g, the reinforcement performance by the carbon black as a filler may be disadvantageous.

Representative 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, N550, N582 , N630, N642, N650, N683, N754, N762, N765, N774, N787, N907, N908, N990 or N991.

The carbon black may be included in an amount of, for example, 3 to 20 parts by weight, for example, 5 to 15 parts by weight, based on 100 parts by weight of the raw rubber.

According to one embodiment of the present invention, the resin may be an AMS (alph methyl stylene)-based glass transition state resin.

According to one embodiment of the present invention, the softening point of the AMS (alph methyl stylene)-based resin may be 85°C to 120°C.

In this specification, “softening point” refers to the temperature at which the resin begins to deform when a certain load is applied to the resin and heated at a certain temperature increase rate.

When an AMS-based resin with a softening point in the range of 85°C to 120°C is included, the content of the AMS-based resin may be 25 to 60 parts by weight based on 100 parts by weight of raw rubber.

As an AMS-based resin, the softening point and content must be within the above range, so that the broadness of the Tg of the vulcanized tread rubber composition can be adjusted and the Tg can be within the above range.

According to one embodiment of the present invention, in addition to the AMS-based resin, the resin includes hydrogenated DCPD (dicyclopentadiene)-C9 copolymer resin, DCPD (dicyclopentadiene) resin, terpene phenol-based resin, and C5-C9 copolymer resin. It may also include polymer resin, or any combination thereof.

For example, the resin of the tire tread rubber composition according to one embodiment of the present invention includes hydrogenated DCPD (dicyclopentadiene)-C9 copolymer resin, DCPD (dicyclopentadiene) resin, terpene phenol-based resin, and C5. -C9 copolymer resin, or any combination thereof.

In this case, the hydrogenated DCPD (dicyclopentadiene)-C9 copolymer resin, DCPD (dicyclopentadiene) resin, terpene phenolic resin, C5-C9 copolymer resin, or any combination thereof. The softening point of the resin may be 100°C to 140°C.

Content of the resin comprising the hydrogenated DCPD (dicyclopentadiene)-C9 copolymer resin, DCPD (dicyclopentadiene) resin, terpene phenolic resin, C5-C9 copolymer resin, or any combination thereof Silver may be 25 to 60 parts by weight based on 100 parts by weight of raw rubber.

A resin containing the hydrogenated DCPD (dicyclopentadiene)-C9 copolymer resin, DCPD (dicyclopentadiene) resin, terpene phenolic resin, C5-C9 copolymer resin, or any combination thereof, has a softening point And when the content is within the above range, it is possible to control the broadness of the Tg of the vulcanized tread rubber composition so that the Tg is within the above range.

For example, the DCPD (dicyclopentadiene) resin may include a repeating unit represented by the following formula (1):

<Formula 1>

In Formula 1, n may be 7 to 45.

For example, the terpene phenol-based resin may include modified terpene phenol resin, polyterpene resin, rosin resin, or modified rosin resin.

For example, the modified terpene phenol resin is a polymer of terpene and phenol and may include a repeating unit represented by the following formula (2):

<Formula 2>

In Formula 2, m may be 7 to 30.

The tire tread rubber composition may optionally further include various additives such as additional vulcanizing agent, vulcanization accelerator, vulcanization accelerator aid, anti-aging agent, antioxidant, or softener. Any of the above various additives can be used as long as they are commonly used in the field to which the present invention pertains, and their content is not particularly limited as it depends on the mixing ratio used in a typical tire tread rubber composition.

As the vulcanizing agent, a sulfur-based vulcanizing agent can be preferably used. The sulfur-based vulcanizing agent includes inorganic vulcanizing agents such as powdered sulfur (S), insoluble sulfur (S), precipitated sulfur (S), and colloidal sulfur, tetramethylthiuram disulfide (TMTD), and tetraethyl Organic curing agents such as tetraethyltriuram disulfide (TETD) and dithiodimorpholine can be used. As the sulfur vulcanizing agent, elemental sulfur or a vulcanizing agent that produces sulfur, for example, amine disulfide, polymer sulfur, etc. may be used.

The vulcanizing agent is preferably included in an amount of 0.5 to 10.0 parts by weight based on 100 parts by weight of the raw rubber in order to achieve an appropriate vulcanization effect and makes the raw rubber less sensitive to heat and chemically stable.

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

The vulcanization accelerators include sulfenamide-based, thiazole-based, thiuram-based, thiourea-based, guanidine-based, dithiocarbamic acid-based, aldehyde-amine-based, aldehyde-ammonia-based, imidazoline-based, xanthate-based and these. Any one selected from the group consisting of combinations may be used.

The sulfenamide-based vulcanization accelerators include, for example, N-cyclohexyl-2-benzothiazylsulfenamide (CBS), N-tert-butyl-2-benzothiazylsulfenamide (TBBS), and N,N-dicyclohexyl. -2-benzothiazylsulfenamide, N-oxydiethylene-2-benzothiazylsulfenamide, N,N-diisopropyl-2-benzothiazolesulfenamide, and any one selected from the group consisting of combinations thereof. Sulfenamide-based compounds can be used.

The thiazole-based vulcanization accelerator includes, for example, 2-mercaptobenzothiazole (MBT), dibenzothiazyl disulfide (MBTS), sodium salt of 2-mercaptobenzothiazole, and zinc salt of 2-mercaptobenzothiazole. , copper salt of 2-mercaptobenzothiazole, cyclohexylamine salt of 2-mercaptobenzothiazole, 2-(2,4-dinitrophenyl)mercaptobenzothiazole, 2-(2,6-di Any one thiazole-based compound selected from the group consisting of ethyl4-morpholinothio)benzothiazole and combinations thereof can be used.

The thiuram-based vulcanization accelerator includes, for example, tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide, tetramethylthiuram monosulfide, dipentamethylenethiuram disulfide, dipentamethylenethiuram monosulfide, and dipentamethylene. Any one thiuram-based compound selected from the group consisting of thiuram tetrasulfide, dipentamethylenethiuramhexasulfide, tetrabutylthiuram disulfide, pentamethylenethiuramtetrasulfide, and combinations thereof can be used.

The thiourea-based vulcanization accelerator includes, for example, any thiourea-based agent selected from the group consisting of thiacarbamide, diethylthiourea, dibutylthiourea, trimethylthiourea, diorthotolylthiourea, and combinations thereof. Compounds can be used.

As the guanidine-based vulcanization accelerator, for example, any guanidine-based compound selected from the group consisting of diphenylguanidine, diorthotolylguanidine, triphenylguanidine, orthotolylbiguanide, diphenylguanidine phthalate, and combinations thereof may be used. You can.

The dithiocarbamate-based vulcanization accelerators include, for example, zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, Zinc dibutyldithiocarbamate, zinc diamyldithiocarbamate, zinc dipropyldithiocarbamate, complex salt of zinc pentamethylenedithiocarbamate and piperidine, zinc hexadecylisopropyldithiocarbamate, octadecyl Zinc isopropyldithiocarbamate, Zinc dibenzyldithiocarbamate, Sodium diethyldithiocarbamate, Piperidine pentamethylenedithiocarbamate, Selenium dimethyldithiocarbamate, Tellurium diethyldithiocarbamate, Dia. Any dithiocarbamate-based compound selected from the group consisting of cadmium milddithiocarbamate and combinations thereof can be used.

The aldehyde-amine or aldehyde-ammonia vulcanization accelerator includes, for example, an aldehyde selected from the group consisting of acetaldehyde-aniline reactant, butyraldehyde-aniline condensate, hexamethylenetetramine, acetaldehyde-ammonia reactant, and combinations thereof. -Amine-based or aldehyde-ammonia-based compounds can be used.

As the imidazoline-based vulcanization accelerator, for example, imidazoline-based compounds such as 2-mercaptoimidazoline can be used, and as the xanthate-based vulcanization accelerator, for example, xanthate-based compounds such as zinc dibutylxanthogenate. Compounds can 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 rubber in order to maximize productivity and rubber physical properties through acceleration of vulcanization speed.

The vulcanization accelerator is a compounding agent used in combination with the vulcanization accelerator to completely enhance its accelerating effect. Any one selected from the group consisting of inorganic vulcanization accelerator, organic vulcanization accelerator, and combinations thereof may be used. .

The inorganic vulcanization accelerator may be any one selected from the group consisting of zinc oxide (ZnO), zinc carbonate, magnesium oxide (MgO), lead oxide, potassium hydroxide, and combinations thereof. there is. 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 any one that works.

In particular, the zinc oxide and the stearic acid can be used together as the vulcanization accelerator. In this case, the zinc oxide is dissolved in the stearic acid to form an effective complex with the vulcanization accelerator, thereby producing sulfur, which is beneficial during the vulcanization reaction. This facilitates the crosslinking reaction of rubber.

When the zinc oxide and the stearic acid are used together, they can be used in an amount of 1 to 10 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 an appropriate vulcanization accelerator. If the content of zinc oxide and stearic acid is less than the above range, the vulcanization speed may be slow and productivity may be reduced, and if it exceeds the above range, a scorch phenomenon may occur and physical properties may be reduced.

The softener is added to the rubber composition to provide plasticity to the rubber to facilitate processing or to reduce the hardness of vulcanized rubber, and refers to oils and other materials used when mixing rubber or manufacturing rubber. The softener refers to process oil or other oils included in the rubber composition. 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 paraffin 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 Co., Ltd., and representative examples of the naphthenic oil include Michang Oil. Examples include N-1, N-2, N-3, etc. from Co., Ltd., and representative examples of the aromatic oil include A-2, A-3, etc. from Michang Oil Co., Ltd.

However, with the recent increase in environmental awareness, it is known that when the content of polycyclic aromatic hydrocarbons (PAHs) contained in the aromatic oil is more than 3% by weight, there is a high possibility of causing cancer, and TDAE ( Treated distillate aromatic extract) oil, MES (mild extraction solvate) oil, RAE (residual aromatic extract) oil, or heavy naphthenic oil can be preferably used.

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

The TDAE oil has excellent low-temperature characteristics and fuel efficiency performance of tires containing the TDAE oil, and also has advantageous properties against environmental factors such as the possibility of PAHs causing cancer.

The above 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, and camellia oil. , jojoba oil, macadamia nut oil, safflower oil, tung oil, and combinations thereof can be used.

The softener is preferably used in an amount of 0 to 10 parts by weight based on 100 parts by weight of the raw rubber in that it improves the processability of the raw rubber.

According to one embodiment of the present invention, the tread rubber composition may not contain a softener, for example, oil.

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

The amine-based anti-aging agent includes 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 may be used. The phenol-based anti-aging agents include phenol-based 2,2'-methylene-bis(4-methyl-6-tert-butylphenol), 2,2'-isobutylidene-bis(4,6-dimethylphenol), 2 , 6-di-t-butyl-p-cresol, and any one selected from the group consisting of combinations thereof can be used. As the quinoline-based anti-aging agent, 2,2,4-trimethyl-1,2-dihydroquinoline and its derivatives can be used, 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. As the wax, waxy hydrocarbon can be preferably used.

Considering the conditions that the anti-aging agent must have a high solubility in rubber in addition to anti-aging effect, must be low in volatility and inert to rubber, and must not inhibit vulcanization, it must be used in an amount of 1 to 10 parts by weight based on 100 parts by weight of the raw rubber. It may be included by weight.

A typical amount of the antioxidant may be, for example, about 1 to about 5 parts by weight. Representative antioxidants include, but are not limited to, diphenyl-p-phenylenediamine and others.

Referring to FIG. 1, the tire 10 includes a tread portion 100, a side wall portion 200, and a bead portion 300.

The tread portion 100 is a portion in contact with the ground in cross-section, and serves to protect the tire from shock and trauma from the road surface. A plurality of blocks divided by grooves may be formed on the surface of the tread portion as described above to improve drainage of the tire.

The tread includes a rubber composition according to an embodiment of the present invention.

The sidewall 200 and the bead portion 300 are located sequentially on both sides along the width direction of the tire centered on the tread portion.

The sidewall 200 is a part that extends from both ends of the tread to form the side of the tire, withstands continuously repeated contraction and expansion during driving, and protects the carcass layer 400 located on the inner side. Do it.

The bead portion 300 is provided at both ends of the sidewall 200 and surrounds the end of the cord paper, and the bead portion 300 includes a bead core 500 including a ring-shaped steel wire.

A carcass layer 400 is located between a pair of left and right bead portions 300 and is bonded to the tire rubber sheet inside the tire to form the frame of the tire. The carcass layer 400 is connected to the bead core 500. ) It is wrapped around the tire from the inside to the outside.

The inner liner 700 is located on one inner surface of the carcass layer 400 and serves to prevent the air inside the tire from escaping.

A belt layer 600 is located on the outer surface of the carcass layer 400 located in the tread portion 100 as a reinforcing layer to increase the elasticity of the tread and ensure maneuverability and stability.

The belt layer rubber may contain a cobalt compound, and the cobalt compound includes cobalt salt, cobalt-boron ester, organic acid cobalt salt, inorganic acid cobalt salt, and non-cobalt salt. As an adhesive system, cobalt salt alone, cobalt- In addition to RH and cobalt-HRH, resins [e.g., methylene acceptor: phenolic, resorcinol, cresol, etc., or donor: hexamethylenetetraamine (HMT), hexamethoxymethylmelamine (HMMA), pentamethoxymethyl There is an adhesive system modified with melamine (PMMA).

In general, to improve adhesion, improvement of the adhesive system of adhesive compound rubber (cobalt-RH, cobalt-HRH, their modified system), improvement of resin used as an adhesive aid and improved performance, improvement of cobalt salt used as an adhesive aid, and adhesion Improvements to the rubber vulcanization system and use of new compounding compositions (reinforcers, carbon black, silica, polymers, chemicals) are being used.

The content of the cobalt compound may include 0.2 to 5.0 parts by weight based on 100 parts by weight of raw rubber, but is not limited thereto.

A cap ply 800 including a hybrid cord may be disposed between the belt layer 600 and the tread portion 100. The cap ply 800 can maintain the performance of the tire by suppressing the flow of the belt layer 600 during driving.

The tire tread rubber composition can be manufactured through a conventional two-step continuous manufacturing process. That is, during the first step (non-productive step) of thermomechanical treatment or kneading at a maximum temperature ranging from 110 to 190° C., preferably at a temperature of 135 to 160° C. and the finishing step in which the crosslinking system is mixed, typically 110° C. It can be manufactured in a suitable mixer using a second step (productive step) of mechanical treatment at a low temperature of less than ℃, for example, 40 to 100 ℃, but is not limited to this.

A tire according to another embodiment of the present invention includes the step of using the tire tread rubber composition when forming a green tire. Any method conventionally used for manufacturing tires can be applied to the method of forming a green tire using the tire tread rubber composition, and detailed description thereof will be omitted in this specification.

In Figure 1, tires for passenger cars are illustrated, but the tire is not limited thereto, and may be tires for passenger cars, racing tires, airplane tires, tires for agricultural machinery, off-the-road tires, truck tires, or bus tires. there is. Additionally, the tire may be a radial tire or a bias tire, and is preferably a radial tire.

The present invention is explained in more detail through the following examples and comparative examples. However, the examples are for illustrating the present invention and are not intended to limit the scope of the present invention.

Example 1 and Comparative Example 1

Each component in Table 1 below was added to a Banbury mixer in the ratio indicated (unit: parts by weight) and mixed. After all ingredients were added to the Tangential type Banbury mixer, the ratio of each ingredient was adjusted so that the fill factor of 1.65L capacity was from 0.65 to 0.70.

division Comparative Example 1 Example 1 SSBR-1 ¹⁾ 54 - SSBR-A ²⁾ 21 21 SSBR-B ³⁾ - 54 BR 25 25 Silica ⁴⁾ 80 80 oil ⁵⁾ 30 - Resin ⁶⁾ - 30 zinc oxide 2.0 2.0 Accelerator ⁷⁾ 3.0 3.0 sulfur 1.1 1.1

1) styrene: vinyl = 22 ~ 28 : 22 ~ 28

2) styrene: vinyl = 30 ~ 45: 30 ~ 65

3) styrene: vinyl = 10 ~ 20 : 12 ~ 30

4) EVONIK, HD-165GR

5) R.A.E.

6) AMS resin: softening point 85 ~ 120℃

7) N,N-Dicyclohexyl-2-benzothiazolesulfenamide

Evaluation example

Evaluation of vulcanized rubber properties

Rubber sheets made from the rubber compositions of Comparative Example 1 and Example 1 were vulcanized in a vulcanizer at 165°C for 10 minutes to prepare specimens. Physical properties such as hardness and tensile strength were evaluated for each specimen. The results are shown in Table 2 below.

HD(hardness)

Using a Shore A type hardness tester, one specimen was measured a total of 5 times on a smooth surface with a thickness of 6 mm or more and a diameter of 10 mm or more according to ASTM D2240-97, and the average value was determined.

Tensile properties

The tensile strength of the cross-linked specimen was measured according to ASTM D412 using a tensile tester (INSTRON). The specimen for measurement was manufactured in a sheet form using a hydraulic press and in a dumbbell form using a specimen cutter. The test conditions were measured at room temperature and the tensile speed was 500 mm/min. Tensile strength (T/S) is a value representing the stress value until the test specimen breaks in a tensile tester, and is measured as the force received per unit area.

elongation

Elongation was measured in a tensile tester by expressing the strain value as a percentage until the test piece breaks.

wet road friction coefficient

It was measured using RTM Friction Tester (UESHIMA, which can evaluate the friction characteristics of tire tread compounds in dry, wet and ice conditions.) The higher the friction coefficient value (μ), the better.)

Dynamic characteristics

As a dynamic property, viscoelasticity was measured using a Gabo viscometer measuring Tanδ value from -70℃ to 70℃ at 0.2% strain and 10Hz frequency. At this time, the temperature at which the Tan δ value is the highest is defined as the glass transition temperature. The larger the Tan δ value at 0°C, the better the wet braking performance, and the larger the Tan δ value at 25°C, the better the dry braking performance.

The evaluation results are shown in Table 2 below.

Comparative Example 1 Example 1 Hardness 72 71 300% modulus (kg/cm ² ) 102 105 Tensile strength (kg/cm ² ) 176 231 elongation 460 550 wet road friction coefficient 0.430 0.460 Tg(℃) -29 -29 ~ -5 0℃ tanδ 0.380 0.396 25℃ tanδ 0.239 0.308

From the results in Table 2, it can be seen that Example 1 and Comparative Example 1 showed similar results in physical properties such as hardness and 300% modulus.

It can be seen that Example 1 is superior to Comparative Example 1 in physical properties such as tensile strength and elongation.

Meanwhile, while Comparative Example 1 had a Tg of -29°C, Example 1 had a Tg in a wide range of -29 to -5°C. As a result, it can be seen that wet braking performance and dry braking performance were improved.

Meanwhile, the tan δ value according to temperature of the tread rubber of Example 1 and Comparative Example 1 was measured and shown in FIG. 2.

Referring to Figure 2, in Comparative Example 1, the peak is clear around -29°C, but in Example 1, the peak is relatively unclear to the extent that the range from -29 to 10°C is said to be the maximum peak point.

This means that the tread rubber vulcanized with the tread rubber composition according to one embodiment of the present invention contains a Tg that is comparable to the braking performance of the summer compound (Tg: around -10°C), so braking performance can be improved in all four seasons. It means there is.

Meanwhile, the values of dynamic modulus E' according to temperature of the tread rubber of Example 1 and Comparative Example 1 were measured and shown in FIG. 3.

Referring to Figure 3, it can be seen that the slope of Example 1 is gentler than that of Comparative Example 1. In the graph of dynamic modulus E' according to temperature, a gentle slope means that braking sensitivity does not change well depending on temperature.

Therefore, it can be seen that the braking sensitivity of the tread rubber vulcanized with the tread rubber composition according to one embodiment of the present invention changes less depending on temperature than that of Comparative Example 1.

Accordingly, it can be seen that tires manufactured with the tire tread rubber composition according to one embodiment of the present invention have little change in braking performance over the four seasons.

Although the above has been described with reference to the embodiments, those skilled in the art may modify and modify the present invention in various ways without departing from the spirit and scope of the present invention as set forth in the claims of the present invention. You will understand that you can change it.

10: tires
100: Tread part
200: Side wall part
300: Bead part
400: Carcass layer
500: bead core
600: Belt layer
700: Innerliner
800: Capfly

Claims (10)

Butadiene rubber and styrene-butadiene rubber as raw material rubber;
Silica as filler; and
A tire tread rubber composition comprising resin,
The resin is an AMS (alph methyl stylene)-based resin with a softening point of 85°C to 150°C,
The content of the AMS-based resin is greater than 30 to 60 parts by weight based on 100 parts by weight of raw rubber,
Tire tread rubber obtained by vulcanizing the tire tread rubber composition is in a glass transition state in the entire range of -29°C to -5°C,
The styrene butadiene rubber is
Solution polymerized styrenebutadiene rubber (SSBR) A with a styrene:vinyl ratio of 30:70 to 70:30; and solution polymerized styrenebutadiene rubber (SSBR) B having a styrene:vinyl ratio of 10:30 to 30:10,
The content ratio of the solution polymerized styrene butadiene rubber (SSBR) B and the solution polymerized styrene butadiene rubber (SSBR) A is 54:21,
Tire tread rubber composition. delete delete delete delete delete delete delete delete A tire manufactured from the tire tread rubber composition of claim 1.

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