KR20220042945A - Rubber composition for tire tread and tire comprising the tire tread - Google Patents

Abstract

The present invention relates to a rubber composition for tire tread which comprises a silane compound derived from sugar, a sustainable material, wherein the rubber composition for tire tread comprises: 100 parts by weight of raw rubber; 50 to 130 parts by weight of a reinforcing filler; and 4 to 30 parts by weight of the silane compound derived from sugar.

Description

A rubber composition for a tire tread and a tire comprising the same

The present invention relates to a rubber composition for an eco-friendly tire tread of a natural component, and specifically, a silica coupling agent derived from saccharides, which is a sustainable material, is relatively inexpensive, reproducible, and environmentally friendly that is naturally decomposed. It relates to a rubber composition for an in-tire tread.

Various efforts are being made around the world to improve environmental problems such as global warming, climate change, resource depletion, and excess environmental capacity, and in particular, to develop technologies that pursue sustainable growth and development, Research on replacing materials with sustainable materials is being actively conducted. As a technology for using eco-friendly raw materials for tires, silica, which is used the most recently instead of carbon black obtained from petroleum raw materials, is a representative example.

Meanwhile, silica, a material widely used as a rubber reinforcing agent in the current tire industry, uses various silica coupling agents to improve chemical bonding with rubber materials. Silica Coupling Agent has an amphoteric property, and one side is hydrophilic and reacts with the silanol group on the surface of the silica, and the other side is hydrophobic, and the sulfur atom binds to the rubber while bonding. have the ability However, the silica coupling agent widely used in the tire industry mainly uses synthetic polymers obtained from petroleum raw materials. The silica coupling agent using the synthetic polymer is difficult to decompose naturally and causes environmental problems because of its unique properties that it cannot be regenerated.

Specifically, the chlorine-based coupling agent used as a silica coupling agent decomposes when in contact with moisture or moisture in the air to generate hydrogen chloride (HCl) gas, which may affect the skin or mucous membranes, and may become a risk factor if it enters the human eye. can In addition, the hydrogen chloride (HCl) gas has disadvantages in that it is difficult to control the hydrolysis process as well as cause equipment corrosion and environmental pollution. Therefore, research on an eco-friendly silica coupling agent to replace it is continuously being made.

An object of the present invention is to provide an environmentally friendly rubber composition for a tire tread that is relatively inexpensive, renewable and naturally decomposing, using a silica coupling agent derived from saccharides, which is a sustainable material as a natural component. will do

Another object of the present invention is to provide a rubber composition for a tire tread comprising the saccharide-derived silane compound having excellent strength and low fuel efficiency by using a saccharide-derived silane compound capable of reacting with silica particles.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention not mentioned may be understood by the following description, and will be more clearly understood by the examples of the present invention. Moreover, it will be readily apparent that the objects and advantages of the present invention may be realized by means of the instrumentalities and combinations thereof indicated in the appended claims.

In order to achieve the above object, the present invention includes a rubber composition for a tire tread comprising 100 parts by weight of raw rubber, 50 to 130 parts by weight of a reinforcing filler, and 4 to 30 parts by weight of a saccharide-derived silane compound.

An object of the present invention is to provide an environmentally friendly rubber composition for a tire tread that is relatively inexpensive, renewable and naturally decomposing, using a silica coupling agent derived from saccharides, which is a sustainable material as a natural component. will do

Another object of the present invention is to provide a rubber composition for a tire tread comprising a saccharide-derived silane compound having excellent strength and low fuel efficiency by using a saccharide-derived silane compound capable of reacting with silica particles.

In addition to the above-described effects, the specific effects of the present invention will be described together while explaining the specific contents for carrying out the invention below.

Hereinafter, each configuration of the present invention will be described in more detail so that those of ordinary skill in the art to which the present invention pertains can easily carry out, but this is only an example, and the scope of the present invention is defined by the following contents Not limited.

The rubber composition for a tire tread according to the present invention may contain 100 parts by weight of raw rubber, 50 to 130 parts by weight of a reinforcing filler, and 4 to 30 parts by weight of a saccharide-derived silane compound.

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

raw rubber

The raw rubber according to the present invention may include natural rubber, solution polymerization styrene-butadiene rubber, and butadiene rubber. Specifically, the raw rubber may include 0.1 to 20 parts by weight of a natural rubber, 40 to 80 parts by weight of a solution polymerization styrene-butadiene rubber, and 10 to 50 parts by weight of a butadiene rubber based on 100 parts by weight of the raw rubber.

In addition, the raw rubber according to the present invention may include 40 to 80 parts by weight of a solution polymerization styrene-butadiene rubber and 10 to 50 parts by weight of a butadiene rubber based on 100 parts by weight of the raw rubber, but may not include natural rubber.

The natural rubber may be at least one selected from the group consisting of general natural rubber, modified natural rubber, and oil extended rubber.

Any general natural rubber may be used as long as it is known as a natural rubber, and the country of origin is not limited. Natural rubber mainly contains cis-1,4-polyisoprene, but may also contain trans-1,4-polyisoprene according to required properties. Accordingly, natural rubber includes, in addition to natural rubber containing cis-1,4-polyisoprene as a main component, natural rubber containing trans-1,4-isoprene as a main component, such as Valata, a type of rubber of the Sapotaceae family from South America. can do.

In the raw rubber included in the present invention, when the content of the natural rubber exceeds 20 parts by weight based on the total weight of the raw rubber, a problem may occur in dispersing the silica filler.

The modified natural rubber means that the general natural rubber is modified or refined. For example, the modified natural rubber may include epoxidized natural rubber (ENR), deproteinized natural rubber (DPNR), hydrogenated natural rubber, and the like.

The oil extended rubber means rubber mixed with an oil agent in rubber to increase flexibility and elasticity at low temperatures, and the natural oil and/or the TDAE oil constituting the present invention may be added in the form of oil-extended rubber. can

Solution polymerized styrene-butadiene rubber refers to a solution polymer with a low content of bound styrene and a moderate vinyl structure. The solution-polymerized styrene-butadiene rubber can facilitate changes in the microstructure or arrangement of monomers in the polymer chain, and the chain ends are bonded using tin or silicone compounds or modified with compounds containing amines or hydroxyl groups. It is possible to reduce the number of ends, reduce the movement of chain ends, and increase the bonding strength with carbon black. Due to the above characteristics, when the solution-polymerized styrene-butadiene is used as a rubber for a tire tread, fuel consumption may be reduced and required physical properties of the tire such as braking performance and abrasion resistance may be adjusted.

In particular, in solution-polymerized styrene-butadiene rubber (S-SBR), the styrene content may correspond to 20 to 50%, and the vinyl content in the butadiene may correspond to 10 to 40%. More preferably, the styrene content may correspond to 30 to 40% and the vinyl content in the butadiene may correspond to 20 to 30%.

Meanwhile, the glass transition temperature (Tg) of the solution-polymerized styrene-butadiene rubber (S-SBR) may correspond to -50 to -20°C. More preferably, the glass transition temperature (Tg) of the solution polymerization styrene-butadiene rubber is -45 to -25 ℃. If the glass transition temperature range is not satisfied, a problem may occur in grip performance of the tire under general road surface conditions and temperatures.

In addition, 30 to 40 parts by weight of SRAE Oil may be added to the solution-polymerized styrene-butadiene rubber (S-SBR) based on 100 parts by weight of the solution-polymerized styrene-butadiene rubber.

Butadiene rubber is a homopolymer of 1,3-butadiene (1,3-butadiene), and is also called polybutadiene rubber. The butadiene rubber may have a cis-1,4-bond, a trans-1,4-bond, and a vinyl1 bond, but the type or ratio thereof is not particularly limited and can be used.

The butadiene rubber may have a cis-1.4-butadiene content of 95% by weight or more, and a Tg of -120 to -100°C. When the butadiene rubber is used, the effect of improving the wear of the tread composition can be obtained.

reinforcing filler

The reinforcing filler according to the present invention includes at least one selected from the group consisting of carbon black and silica, and the content of the reinforcing filler may include 50 to 130 parts by weight based on 100 parts by weight of the raw rubber.

When the reinforcing filler includes both carbon black and silica, the reinforcing filler may include 50 to 130 parts by weight of highly dispersible silica and 5 to 20 parts by weight of carbon black, based on 100 parts by weight of raw rubber, When the content of the sexual filler is 50 parts by weight or less, the filler reinforcing effect is lowered, so that the hardness and elastic modulus may be lowered, and the grip performance may be lowered. When the reinforcing filler exceeds 130 parts by weight, compound processability may be deteriorated.

The reinforcing filler is a component added to impart reinforcing properties to the tire. Among them, carbon black may be added to improve tire abrasion performance and chip-cut performance.

The carbon black may have an iodine adsorption surface area per gram (I ₂ SA) of 30 to 180 m ² /g, and an n-dibutyl phthalate (DBP) oil absorption of 60 to 180 cc/100g, but this The technical spirit of the invention is not limited thereto.

When the iodine adsorption of the carbon black exceeds 180 m ² /g, the processability of the rubber composition for a tire tread may be disadvantageous, and if it is less than 30 m ² /g, the reinforcing performance by the carbon black as a filler may be disadvantageous.

In addition, when the DBP oil absorption amount of the carbon black exceeds 180cc/100g, the processability of the rubber composition for a tire tread may decrease, and if it is less than 60cc/100g, the reinforcing 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.

As the highly dispersible silica, both those prepared by a wet method or a dry method may be used, and commercially available products include Ultrasil VN3, 7000GR (Evonik), Z1165MP, Z195MP (Solvay), and the like.

The highly dispersible silica may have a cetyltrimethylammonium bromide (CTAB) adsorption value of 150 to 170 m ² /g. It is preferable to have a value in the above range for realizing compound physical performance such as tensile strength, elongation, modulus of elasticity, and the like. Accordingly, in the case of having an adsorption value higher than the above range, there may be a problem that silica is not dispersed smoothly in the compound. , the modulus of elasticity may be lowered.

In addition, the highly dispersible silica may have a nitrogen adsorption surface area per gram (N ₂ SA) of 160 to 180 m ² /g. In the case of having an adsorption value higher than the above range, there may be a problem that silica is not dispersed smoothly in the compound. etc. may be lowered.

Sugar-derived silane compounds

The rubber composition for a tire tread according to the present invention may include a saccharide-derived silane compound, which is defined as a saccharide-derived silane compound. Specifically, the sugar-derived silane compound may include 4 to 30 parts by weight based on 100 parts by weight of the raw rubber.

The saccharide-derived silane compound facilitates dispersion of silica particles in the compound, prevents aggregation of the dispersed silica particles through covalent bonds between rubber and silica, and induces a coupling bond between rubber and filler to improve physical properties of the compound can do it If the content range is not satisfied, it is difficult to disperse the silica particles and silica aggregates may be formed in the rubber composition, and the coupling bond between the rubber and the filler may be significantly lowered.

The saccharide-derived silane compound according to the present invention may include a saccharide and a first carbon chain. Specifically, the saccharide may correspond to any one selected from the group consisting of monosaccharides, disaccharides, oligosaccharides, and polysaccharides, and more specifically, maltose, glucose, fructose, galactose, xylose, mannose, ribose, and arabi. It may include one or more repeating units selected from the group consisting of north, lyxose, allose, altrose, and talose.

The first carbon chain may include at least one selected from a disulfide bond, a thiol, and a double bond between carbons.

The saccharide-derived silane compound according to the present invention may include a saccharide oxide and a second carbon chain. Specifically, the saccharide oxide may correspond to at least one selected from the group consisting of saccharides containing a carboxyl group and saccharides containing a lactone group. The second carbon chain, like the first carbon chain, may include at least one selected from a disulfide bond, a thiol, and a double bond between carbons. For example, the second carbon chain may be the same as or different from the first carbon chain.

Existing silica contains a hydrophilic functional group, a hydroxyl group, on its surface, and the interaction between the silica aggregates is very strong, so there is a problem in that it is not easily dispersed in a non-polar rubber. Due to this, it is difficult to disperse the highly interactive silica in the rubber material, thereby weakening the chemical bonding force between the silica and the rubber material.

The silica coupling agent proposed to solve this problem may include a hydrophilic functional group capable of reacting with a silanol group on the silica surface, which is an amphoteric property, and a hydrophobic functional group capable of bonding to rubber.

However, in the silica coupling agent, hydrogen bonds are formed with silica particles having a large number of polar silanol groups on the surface. Silica still has a problem of poor dispersibility because it forms an aggregate well.

In order to solve the above problems, the saccharide-derived silane compound according to the present invention provides a rubber composition for a tire tread in which silica is well dispersed in the rubber composition for a tire tread and improves filler-rubber interaction can do.

Specifically, the rubber composition for a tire tread including the saccharide-derived silane compound can realize a covalent bond between rubber and silica in the compound, and prevent aggregation of silica to facilitate dispersion, thereby solving the above problems.

The highly reactive functional group included in the carbon chain constituting the saccharide-derived silane compound reacts with the rubber material to form a covalent bond, thereby solving the problem that the connection between the silica coupling agent and the rubber material is weak. A detailed description of the functional group will be described later.

By forming the covalent bond, a rubber specimen prepared using a rubber composition for a tire tread including a saccharide-derived silane compound has a higher filler-rubber interaction than a rubber specimen prepared using a rubber composition that does not use a silica coupling agent. Excellent strength can be secured due to the large Filler-Rubber Interaction.

Accordingly, the rubber composition for a tire tread including the saccharide-derived silane compound according to the present invention can provide a tire having low fuel efficiency due to improved silica dispersibility.

As another problem, since the petrochemical synthetic silica coupling agent is not derived from nature, it cannot be regenerated, and there is a possibility that harmful gas may be generated in the process of manufacturing the silica coupling agent, thereby harming the human body. For example, a chlorine-based coupling agent used as a silica coupling agent is decomposed when in contact with moisture or moisture in the air to generate hydrogen chloride (HCl) gas, which may affect human skin or mucous membranes, etc. could put you at risk. The hydrogen chloride (HCl) gas not only causes equipment corrosion and environmental pollution, but also causes difficulties in controlling the hydrolysis process.

In addition, the synthetic silica coupling agent widely used in the tire industry mainly uses a synthetic polymer obtained from petroleum raw materials, so it is relatively expensive, and it is difficult to regenerate and does not decompose naturally, so it is not environmentally friendly.

In order to solve this problem, the saccharide-derived silane compound according to the present invention may provide a rubber composition for a tire tread that can be recycled by utilizing saccharides or saccharide oxides of naturally-derived components. That is, an object of the present invention is to prevent the generation of harmful gases by using a saccharide-derived silane compound, which is a sustainable material, and to provide a nature-friendly environment. For example, looking at the manufacturing process of the saccharide-derived silane compound, it can be seen that no harmful gas such as hydrogen chloride (HCl) is generated during the manufacturing process.

Specifically, maltose-polybutadiene, which is one of the saccharide-derived silane compounds according to the present invention, is prepared by adding maltose monohydrate to a mixture of acetic anhydride and sodium acetate at room temperature. Even in this case, it has the advantage of not generating harmful gases to the human body.

In particular, maltose, a part of saccharides, is a disaccharide in which two glucose units are bonded by a glycosidic bond. It can be easily manufactured in a harmless manufacturing environment by adding an enzyme such as amylase to liquefied starch, and using microorganisms It can be prepared in a variety of ways. The technical spirit of the present invention is not limited to the method for producing saccharides.

The saccharide-derived silane compound according to the present invention may include at least one selected from the group consisting of Chemical Formulas 1, 2, and 3 below.

[Formula 1]

[Formula 2]

[Formula 3]

For example, in Chemical Formulas 1 to 3, the saccharide moiety including a hydroxyl group interacts with silica to prevent agglomeration or formation of an aggregate between silicas, thereby preventing a decrease in silica dispersion degree.

The carbon chain linked to the saccharide may include a disulfide bond (S-S), and the disulfide bond may be decomposed to form a cross-linked bond with the rubber. As a result, filler-rubber interaction between silica and rubber may be improved through the saccharide-derived silane compound.

In addition, the saccharide-derived silane compound according to the present invention may include a carbon chain including saccharides and a thiol functional group. The carbon chain including the thiol functional group may form a cross-linked bond with the rubber like the disulfide bond.

Additionally, the carbon chain of the saccharide-derived silane compound according to the present invention may include a double bond between carbons. For example, the saccharide-derived silane compound may include at least one selected from the following Chemical Formulas 4 and 5.

[Formula 4]

[Formula 5]

In order for Chemical Formulas 4 and 5 to interact with the raw rubber, free sulfur must be added to the double bond between carbons under high temperature conditions. The double bond between carbons may be decomposed by high temperature or harsh conditions to form a cross-linked bond with the rubber by free sulfur. On the other hand, free sulfur (Free Sulfur) means sulfur in a free state without bonding.

Meanwhile, the following Reaction Scheme 1 may be used to prepare Formula 4 above. The following is a specific experimental method for preparing Chemical Formula 4 above.

[Scheme 1]

To a mixture of acetic anhydride (47.0 mL, 500 mmol) and sodium acetate (8.20 g, 100 mmol), product 1a, Maltose monohydrate (Maltose monohydrate, 9.00 g, 25.0 mmol) is added at room temperature. . After the mixture is refluxed with stirring at 100 °C for 3 hours, diluted with 50 mL of methanol, precipitated in 500 mL of cold water, filtered, and dried to obtain Product 2.

Product 2 (3.2 g, 4.7 mmol) in 10 mL of anhydrous chloroform was added with propargyl alcohol (propargyl alcohol, 5.0 mL, 85.9 mmol), and then BF ₃ OEt ₂ (Boron trifluoride diethyl etherate, 5.0 mL, 40.5 mmol) ) is added dropwise. After creating a nitrogen environment, the mixture is stirred at room temperature for 45 hours. After adding 50 mL of ethyl acetate, the diluted solution is washed 3 times with a saturated aqueous sodium hydrogen carbonate solution. The organic layer was dried over magnesium sulfate (MgSO ₄ ) and then concentrated in vacuo to obtain product 3.

1 g of polybutadiene (Mn = 2500 g/mol) dried overnight in a vacuum oven is dissolved in 20 mL of anhydrous dichloromethane. Toluenesulfonyl chloride (Toluenesulfonyl chloride, 764 mg, 4 mmol) was added to the product 4 solution and stirred. After adding triethylamine (TEA, 2.08 mL, 14 mmol) dropwise to the mixture, the mixture is stirred at room temperature for 24 hours. The product 5, which was precipitated in excess methanol and phase-separated using a centrifuge, was dried and obtained.

1 g of product 5 is dissolved in a mixed solution of tetrahydrofuran (THF; 16 mL) and dimethylformamide (DMF; 4 mL), and sodium azide (sodium azide, 260 mg) is added. After stirring at 50 °C for 24 h, it is filtered and precipitated in excess methanol. After separation using a centrifuge, the product 6 was obtained by drying.

Product 3 (215.4 mg, 0.3 mmol) and product 6 (750 mg, 0.3 mmol) were each dissolved in 4 mL of anhydrous tetrahydrofuran, and then rapidly frozen using liquid nitrogen to remove air by vacuum. Repeat freezing and thawing to remove air sufficiently, and then transfer to the flask containing the catalyst (CuBr, 14 mg) and ligand (PMDETA, 20 μL). After removing the air from the mixture, it is stirred at 50 °C for 20 hours. The solution was diluted by adding 50 mL of tetrahydrofuran and passed through an alumina column to remove the catalyst. After reducing the volume by concentration in vacuo, it was precipitated in methanol, separated using a centrifugal separator, and dried to obtain product 7.

After dissolving product 7 (500 mg) in a mixed solution of tetrahydrofuran (6 mL) and methanol (2 mL), add sodium methoxide solution (NaOMe 25 wt% in MeOH) dropwise while stirring to obtain a pH of 8 do. After stirring at room temperature for 3 hours, the mixture was precipitated in excess methanol, separated by centrifugation and dried to obtain Chemical Formula 4 above.

On the other hand, in order to prepare the above formula (5), the following Scheme 2 may be used. The following is a specific experimental method for preparing Chemical Formula 5.

[Scheme 2]

A mixture of product 9, farnesol (1 mL, 4 mmol), anhydrous dichloromethane (10 mL) is cooled to 0 °C. Methanesulfonyl chloride (687 mg, 6 mmol) and triethylamine (837 μL (microliter), 6 mmol) are added dropwise. After stirring at room temperature for 1 hour, the same amount of methanesulfonyl chloride and triethylamine are added and the mixture is stirred for another hour. After washing 5 times with a saturated aqueous solution of ammonium chloride, the organic layer was dried over magnesium sulfate and concentrated in vacuo to obtain a product 10.

A mixture of product 10 (1 g, 3.33 mmol), sodium azide (325 mg, 5 mmol), and dimethylformamide (5 mL) is heated to 50 °C in a nitrogen environment and stirred for 24 h. After adding 50 mL of ethyl acetate, the diluted solution is washed 3 times with water. The organic layer was dried over magnesium sulfate and concentrated in vacuo to obtain product 11.

After dissolving product 3 (1.65 g, 2.02 mmol) and product 11 (500 mg, 2.02 mmol) in 5 mL of anhydrous dimethylformamide, respectively, the subsequent procedure is the same as that of product 7 above. After the catalyst was removed, the concentrated solution was diluted with 50 mL of ethyl acetate, and the organic layer washed with water was concentrated in vacuo to obtain a product 12.

Then, the above formula (5) was obtained in the same manner as for product (8).

additive

Meanwhile, the rubber composition for a tire tread according to the present invention may optionally further include a vulcanizing agent, a vulcanization accelerator, a softening agent, an anti-aging agent, and a compounding agent such as a vulcanizing agent and oil. Any of the above various additives may 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 a compounding ratio used in a conventional rubber composition for a tire tread.

In an exemplary embodiment, the oil may be a petroleum oil, and the petroleum oil is not particularly limited as long as it is a processing oil commonly used in rubber compositions for tires, but is a group consisting of aromatic oils, naphtanic oils, and paraffinic oils. One or more selected from may be used. Preferably, it may be an aromatic oil having good compatibility with rubber and good dispersibility of carbon black, and TDAE oil or RAE oil having a low PCA (Polycyclic aromatic) content is more preferable, but is not limited thereto.

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily carry out, but this is only an example, and the scope of the present invention is defined by the following contents Not limited.

production example

Rubber specimens including rubber compositions for tire treads according to Examples and Comparative Examples were prepared with the composition shown in Table 1 below. The numerical values in Table 1 below mean the weight ratio of additives other than the raw rubber to 100 parts by weight of the raw rubber.

<Example 1>

Example 1 is a rubber specimen including a saccharide-derived silane compound according to the present invention, wherein the saccharide-derived silane compound corresponds to Formula 1 above.

Formula 1 may be prepared by the following process.

Maltose (5.82 mmol) and cystamine (2.92 mmol) are dissolved in a pH 8.3 borate buffer solution (Borate Buffer Solution, 0.1M, 20 mL). Add NaCNBH ₃ (Sodium Cyanoborohydride, 4.4 g, 70 mmol) to the mixture and stir at 50 °C for 24 hours. After the solution is precipitated in acetone, the precipitate is recovered by a centrifuge and dried to prepare Chemical Formula 1 above.

Example 1 may be a rubber composition for a tire tread in which 7 parts by weight of a coupling agent is additionally added based on 100 parts by weight of raw rubber.

<Example 2>

Example 2 is a rubber specimen including a saccharide-derived silane compound according to the present invention, wherein the saccharide-derived silane compound corresponds to Formula 2 above.

Dissolve D-(+)-glucose (D-(+)-Glucose) and cystamine (2.92 mmol) in pH 8.3 Borate Buffer Solution (0.1M, 20mL). Add NaCNBH ₃ (Sodium Cyanoborohydride, 4.4 g, 70 mmol) to the mixture and stir at 50 °C for 24 hours. After the solution is precipitated in acetone, the precipitate is recovered by a centrifuge and dried to prepare Chemical Formula 2 above.

Example 2 may be a rubber composition for a tire tread in which 6 parts by weight of a coupling agent is additionally added based on 100 parts by weight of raw rubber.

<Example 3>

Example 3 is a rubber specimen including a saccharide-derived silane compound according to the present invention, wherein the saccharide-derived silane compound corresponds to Formula 3 above.

δ-Gluconolactone (δ-Gluconolactone) and cystamine (2.92 mmol) are dissolved in pH 8.3 borate buffer solution (Borate Buffer Solution, 0.1M, 20mL). Add NaCNBH ₃ (Sodium Cyanoborohydride, 4.4 g, 70 mmol) to the mixture and stir at 50 °C for 24 hours. After the solution is precipitated in acetone, the precipitate is recovered by a centrifuge and dried to prepare Chemical Formula 3 above.

Example 3 may be a rubber composition for a tire tread in which 5 parts by weight of a coupling agent is additionally added based on 100 parts by weight of raw rubber.

<Comparative Example 1>

Comparative Example 1 is a rubber specimen including a rubber composition for a tire tread that does not include a coupling agent, in contrast to Examples 1 to 3.

Unit: parts by weight Example 1 Example 2 Example 3 Comparative Example 1 NR ¹⁾ 10 10 10 10 S-SBR ²⁾ 60 60 60 60 BR ³⁾ 30 30 30 30 carbon black ⁴⁾ 10 10 10 10 Silica ⁵⁾ 60 60 60 60 coupling agent 1 ⁶⁾ 7 - - - coupling agent 2 ⁷⁾ - 6 - - coupling agent 3 ⁸⁾ - - 5 - oil 10 10 10 10 zinc oxide 3 3 3 3 antioxidant 6 6 6 6 vulcanizing agent 0.7 0.7 0.7 0.7 accelerant 2.7 2.7 2.7 2.7 1) NR (Natural Rubber): It is a rubber obtained from nature, and its chemical name is polyisoprene.
2) S-SBR: Styrene content is 35%, vinyl content in butadiene is 25%, Tg is -35 ℃ solution polymerization styrene-butadiene rubber (S-SBR), including 37.5 parts by weight of SRAE Oil.
3) BR: butadiene rubber manufactured with neodymium or nickel catalyst
4) Carbon black: Carbon black with an iodine adsorption value of 80 m ² /g and DBP oil absorption of 105cc/100g
5) Silica: highly dispersible silica with nitrogen adsorption value of 175 m ² /g and CTAB value of 160 m ² /g
6) Coupling agent 1: Formula 1 above
7) Coupling agent 2: Formula 2
8) Coupling agent 3: Formula 3

[Measurement of physical properties of rubber specimens using rubber composition for tire tread]

For the rubber specimens prepared according to the Examples and Comparative Examples, 1) modulus measurement, 2) breaking energy measurement, 3) Tg measurement, and 4) 60°C tanδ measurement were evaluated and shown in Table 2 below.

Each evaluation method is as follows.

1) Modulus measurement: Each modulus is tensile strength at 100% and 300% elongation, measured according to the ISO 37 standard. The higher the value, the better the strength, and it can be inferred that the bonding force between the filler and rubber is increased. .

2) Breaking energy measurement: According to the ISO 37 standard, it means the energy when the rubber breaks, and the strain energy until the specimen breaks in a tensile tester was measured in a numerical way.

3) Tg measurement: Measure Tg using a DSC device that can measure the change in thermal energy according to temperature change. The DSC device measures the difference in energy input as a function of temperature while changing the sample and reference temperatures.

4) 60°Ctanδ measurement: For viscoelasticity, G′, G〃, and tanδ were measured from -60°C to 70°C under 10Hz frequency at 0.5% strain using an ARES measuring instrument. Here, 60 °Ctanδ is a measure of the rotational resistance at 60 °C, and the lower the value, the better the fuel economy characteristics are, which is a result of the silica coupling agent improving the silica dispersibility in the compound.

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

Example 1 Example 2 Example 3 Comparative Example 1 100% modulus 14 11.2 13.55 10 300% modulus 64 46 53 33 Breaking energy (kgf/cm ² ) 193 183 183 213 Tg (℃) -21.8 -23.4 -24.1 -21.8 60℃ tan δ 0.072 0.086 0.079 0.091

As shown in Table 2, all of Examples 1 to 3, which are rubber specimens containing a saccharide-derived silane compound according to the present invention, have superior tensile strength and improved silica dispersibility than Comparative Example 1 without using a coupling agent. As a result, it was confirmed that low fuel economy characteristics were exhibited.

Claims (9)

100 parts by weight of raw rubber;
50 to 130 parts by weight of a reinforcing filler; and
A rubber composition for a tire tread comprising 4 to 30 parts by weight of a sugar-derived silane compound. The method of claim 1,
The saccharide-derived silane compound is
a sugar and a first carbon chain;
The first carbon chain includes at least one selected from a disulfide bond, a thiol, and a double bond between carbons. 3. The method of claim 2,
The rubber composition for a tire tread, wherein the saccharide is at least one selected from the group consisting of monosaccharides, disaccharides, oligosaccharides, and polysaccharides. 3. The method of claim 2,
The saccharide is a tire comprising one or more repeating units selected from the group consisting of maltose, glucose, fructose, galactose, xylose, mannose, ribose, arabinose, lyxose, allose, altrose and talose. A rubber composition for a tread. The method of claim 1,
The saccharide-derived silane compound is
a saccharide oxide and a second carbon chain;
The second carbon chain comprises at least one selected from a disulfide bond, a thiol, and a double bond between carbons. 6. The method of claim 5,
The saccharide oxide is at least one selected from the group consisting of saccharides containing a carboxyl group and saccharides containing a lactone group. The method of claim 1,
The raw rubber is a rubber composition for a tire tread comprising 0.1 to 20 parts by weight of natural rubber, 40 to 80 parts by weight of solution polymerization styrene-butadiene rubber, and 10 to 50 parts by weight of butadiene rubber. The method of claim 1,
The saccharide-derived silane compound is at least one selected from the group consisting of the following Chemical Formulas 1 to 5. A rubber composition for a tire tread.
[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

A tire comprising the rubber composition for a tire tread according to any one of claims 1 to 8.