KR20240045724A - Rubber composition for tire and tire manufactured therefrom - Google Patents

Abstract

The present invention relates to a rubber composition for tires and a tire manufactured using the same. The rubber composition for tires includes raw rubber, a reinforcing agent, a vulcanizing agent, and a silane coupling agent having a specific structure. The rubber composition for tires according to the present invention can contribute to providing a tire with excellent processability (moldability) and improved mechanical properties.

Description

Rubber composition for tires and tires manufactured therefrom {RUBBER COMPOSITION FOR TIRE AND TIRE MANUFACTURED THEREFROM}

The present invention relates to a rubber composition for tires and tires manufactured therefrom, and specifically, to a rubber composition for tire treads with improved processability and processability using a reversible reaction of hindered urea, and a tread manufactured therefrom. It relates to tires including.

Recently, as regulations on environmental issues are becoming more and more stringent around the world, regulations on vehicle emissions are also gradually being strengthened. In particular, with the introduction of WLTP (Worldwide Harmonized Light vehicles Test Procedure), a new fuel efficiency measurement method, since September 2017, regulations on vehicle emissions have been further strengthened. Accordingly, there is a demand for the development of vehicles with high fuel efficiency and high performance to reduce vehicle exhaust gases.

One of the ways to increase the fuel efficiency of the vehicle is to improve the mechanical properties of tires. For example, tires with improved tensile strength and wear resistance are manufactured using a silica-containing rubber composition and applied to vehicles.

However, the processability and processability of rubber compositions containing silica vary greatly depending on the silica content, so there is a limit to improving the mechanical properties of tires. In other words, in order to manufacture tires with high mechanical properties, the rubber composition must contain a high content of silica, which reduces the dispersibility of the rubber composition and increases viscosity, thereby reducing the processability and processability of the rubber composition.

Therefore, there is a need to develop a rubber composition that can manufacture tires with excellent mechanical properties while improving processability and processability.

Republic of Korea Patent Publication No. 2022-0086633

The purpose of the present invention is to solve the problem of lowering dispersion and processability when a high content of silica is contained in a rubber composition for tires, using the reversible reaction of hindered urea. The aim is to provide a rubber composition for tires that can be used.

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

In order to solve the above problems, the present invention includes: raw rubber; adjuvant; vulcanizing agent; and a silane coupling agent, wherein the silane coupling agent includes a urea adduct silane compound containing a urea group and a sulfide group.

According to the present invention, the urea addition silane compound may be a compound represented by the following formula (1):

[Formula 1]

In Formula 1,

R ₁ is each independently an alkoxy group having 1 to 4 carbon atoms,

R ₂ is selected from the group consisting of an alkyl group having 1 to 5 carbon atoms and an alkoxy group having 1 to 4 carbon atoms.

Additionally, according to the present invention, the urea addition silane compound may be a compound represented by the following formula (2):

[Formula 2]

Additionally, according to the present invention, the rubber composition for tires may include 1 to 15 parts by weight of the silane coupling agent based on 100 parts by weight of the raw rubber.

Meanwhile, the present invention provides a tire including a tread manufactured from the above tire rubber composition.

According to the present invention, as a silane coupling agent containing a urea adduct silane compound, which undergoes a reversible reaction at a specific temperature (e.g., 100° C.), is introduced into the tire rubber composition, the viscosity of the tire rubber composition is required. It is possible to improve the processability (moldability) and processability of the rubber composition for tires by controlling it to a certain level. In addition, by manufacturing a tire using the tire rubber composition, a tire (specifically, a tire tread) with excellent mechanical properties (tensile strength, abrasion resistance, etc.) can be provided.

Hereinafter, the present invention will be described in detail. Here, the present invention is not limited to the content described below and may be modified into various forms as long as the gist of the invention is not changed.

In this specification, the term "include" is intended to specify specific characteristics, areas, steps, processes, elements and/or components, and unless specifically stated to the contrary, other characteristics, areas, steps, processes, elements and /or does not exclude the presence or addition of ingredients.

All numbers and expressions representing the amounts of components, reaction conditions, etc. described in this specification can be understood as being modified by the term “about” in all cases unless otherwise specified.

Rubber composition for tires

The rubber composition for tires according to the present invention is for manufacturing tires (specifically, the tread portion of a tire) and includes raw rubber, a reinforcing agent, a vulcanizing agent, and a silane coupling agent, which will be described in detail as follows.

raw rubber

The raw rubber contained in the rubber composition for tires according to the present invention serves to form the base base of tire rubber (tire tread rubber). This raw rubber is not particularly limited and may specifically be made of natural rubber, synthetic rubber, or a combination thereof.

The natural rubber may be conventional natural rubber or modified natural rubber. Specifically, the natural rubber may be a rubber containing cis-1,4-polyisoprene or trans-1,4-polyisoprene. The modified natural rubber may be a rubber containing at least one selected from the group consisting of epoxidized natural rubber (ENR), deproteinized natural rubber (DPNR), and hydrogenated natural rubber.

The synthetic rubber may be a conventional synthetic rubber. Specifically, the synthetic rubber includes styrene butadiene rubber (SBR), butadiene rubber (BR), butyl rubber, emulsion polymerized styrene butadiene rubber (E-SBR), solution polymerized styrene butadiene rubber (S-SBR), modified styrene butadiene rubber, and modified styrene butadiene rubber. Butadiene rubber, epichlorohydrin rubber, nitrile rubber, hydrogenated nitrile rubber, nitrile butadiene rubber (NBR), brominated polyisobutylisoprene-co-paramethyl styrene (BIMS) rubber, urethane rubber, fluorine rubber, silicone rubber, styrene. Ethylene butadiene styrene rubber, ethylene propylene rubber, ethylene propylene diene rubber (EPDM), hypalon rubber, chloroprene rubber, ethylene vinyl acetate rubber, acrylic rubber, hydrin rubber, vinylbenzyl chloride styrene butadiene rubber, bromomethyl styrene butyl rubber, It may be a rubber containing one or more selected from the group consisting of styrene butadiene maleate rubber, styrene butadiene carboxylic acid rubber, epoxy isoprene rubber, ethylene propylene maleate rubber, and nitrile butadiene carboxylic acid rubber.

For example, considering the fairness of the rubber composition for tires, processability, and mechanical properties of tire rubber, the raw material rubber is 60:40 to 90:10, 65% of the styrene butadiene rubber (SBR) and the butadiene rubber (BR). :35 to 85:15, 70:30 to 80:20, or 70:30 to 75:25.

adjuvant

The reinforcing agent included in the rubber composition for tires according to the present invention serves to secure the strength and wear resistance of tire rubber (tire tread rubber). This reinforcing agent is not particularly limited, and may specifically include one or more selected from the group consisting of silica, carbon black, calcium carbonate, clay, aluminum hydroxide, silicate, and talc. More specifically, the reinforcing agent may be made of silica and carbon black.

The silica may have a BET surface area of 100 to 300 m2/g, 120 to 280 m2/g, 150 to 250 m2/g, or 180 to 220 m2/g. As the BET surface area of the silica is within the above range, tire rubber with excellent strength and wear resistance can be provided while ensuring the dispersibility of the silica.

The carbon black may have an iodine adsorption value of 100 to 200 g/kg, 110 to 180 g/kg, 120 to 160 g/kg, or 130 to 150 g/kg. Additionally, the carbon black may have a DBP (disinfection by product) adsorption value of 100 to 180 ml, 110 to 165 ml, 120 to 150 ml, or 125 to 135 ml per 100 g. Since the iodine adsorption value and the DBP adsorption value of the carbon black are within the above range, tire rubber with excellent strength and wear resistance can be provided while ensuring the dispersibility of the carbon black.

Meanwhile, when the reinforcing agent consists of the silica (a) and the carbon black (b), their mixing ratio (a:b) (mixing ratio of silica and carbon black with respect to 100 parts by weight of raw rubber) is not particularly limited. Specifically, it may be a weight ratio of 120:5 to 50:5, a weight ratio of 100:5 to 60:5, or a weight ratio of 80:5 to 70:5. When the mixing ratio of the silica and the carbon black is within the above range, tire rubber with excellent strength and wear resistance can be provided.

These reinforcing agents may be included in the tire rubber composition at 50 to 150 parts by weight, 65 to 140 parts by weight, 80 to 130 parts by weight, or 90 to 110 parts by weight based on 100 parts by weight of the raw rubber. As the content of the reinforcing agent is within the above range, tire rubber with excellent strength and wear resistance can be provided while ensuring processability and processability of the rubber composition for tires.

vulcanizing agent

The vulcanizing agent included in the rubber composition for tires according to the present invention serves to cause a crosslinking reaction between raw rubber materials. This vulcanizing agent is not particularly limited, and may specifically include organic peroxides or sulfur-based compounds.

The organic peroxide specifically includes benzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, 2,5-dimethyl-2, 5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 1,3-bis(t-butylperoxypropyl)benzene, di-t-butylperoxy-diisopropylbenzene, t-butylperoxybenzene, 2,4-dichlorobenzoyl peroxide, 1,1-di- It may include one or more selected from the group consisting of t-butylperoxy-3,3,5-trimethylsiloxane and n-butyl-4,4-di-t-butylperoxyvalerate.

The sulfur-based compound specifically consists of sulfur, tetramethylthiuram disulfide (TMTD), tetraethyltriuram disulfide (TETD), dithiodimorpholine, and amine disulfide. It may include one or more types selected from the group.

This vulcanizing agent may be included in the rubber composition for tires in an amount of 0.5 to 3 parts by weight, 0.5 to 2 parts by weight, 1 to 2 parts by weight, or 1 to 1.5 parts by weight based on 100 parts by weight of the raw rubber. As the content of the vulcanizing agent is within the above range, the crosslinking reactivity of the raw rubber can be secured and the vulcanizing agent can be prevented from remaining in the tire rubber.

Silane coupling agent

The silane coupling agent included in the rubber composition for tires according to the present invention serves to control the viscosity of the rubber composition for tires while increasing the bonding property between the raw rubber and the reinforcing agent. These silane coupling agents include urea adduct silane compounds containing a urea group and a sulfide group. As the silane coupling agent contains the urea-added silane compound, the viscosity of the raw rubber is reduced under heat input conditions and the mobility of the cross-linked polymer chain is increased, resulting in significantly excellent processability and processability. A rubber composition for tires can be provided. These silane coupling agents may further include commonly known silane compounds.

The urea group has the property of showing a temperature-dependent reversible reaction (binding) under heat input conditions, as shown in Scheme 1 below. This urea group is called hindered urea. Since the urea-added silane compound contains a urea group that exhibits the reversible reaction, when heat is applied during the process of vulcanizing the tire rubber composition, the viscosity of the tire rubber composition increases. This lowers the processability (moldability) of the rubber composition for tires and can be maximized.

[Scheme 1]

The sulfide group is a functional group having 2 to 4 sulfur atoms, and participates in a crosslinking reaction to form a chemical bond between the raw rubber and the reinforcing agent.

The urea-addition silane compound containing such a urea group and a sulfide group may be a compound represented by the following formula (1).

[Formula 1]

In Formula 1,

R ₁ is each independently an alkoxy group having 1 to 4 carbon atoms, and R ₂ is each independently selected from the group consisting of an alkyl group having 1 to 5 carbon atoms and an alkoxy group having 1 to 4 carbon atoms.

Specifically, R ₁ and R ₂ may each independently be a methoxy group or an ethoxy group. Here, a plurality of R ₁ may be the same or different from each other, and a plurality of R ₂ may also be the same or different from each other.

The urea-addition silane compound, which is the compound represented by Formula 1, may be specifically a compound represented by Formula 2 below.

[Formula 2]

In the compound represented by Formula 2, the urea group is sterically hindered by the methoxy phenyl structure, and because of this, the compound represented by Formula 2 undergoes a temperature-dependent reversible reaction under heat input conditions. It will appear.

The compound represented by Chemical Formula 2 is an isocyanate group of isocyanato propyl triethoxy silane (IPTES) and (4-((4-amino-3-methoxy) as shown in Scheme 2 below. Phenyl) dithio) -2-methoxyphenyl) amine ((4-((4-Amino-3-methoxyphenyl) dithio) -2-methoxyphenyl) amine) obtained through urea reaction between the amine groups. You can.

[Scheme 2]

This silane coupling agent may be included in the tire rubber composition at 1 to 15 parts by weight, 2 to 13 parts by weight, 2 to 10 parts by weight, or 2 to 8 parts by weight based on 100 parts by weight of the raw rubber. As the content of the silane coupling agent is within the above range, the viscosity of the tire rubber composition is controlled low to the required level, thereby maximizing the processability and processability of the tire rubber composition, and providing tire rubber with excellent mechanical properties. You can.

By including the silane coupling agent, the rubber composition for tires according to the present invention may have a viscosity of 50 to 100 MU, 60 to 90 MU, or 70 to 80 MU.

Meanwhile, the rubber composition for tires according to the present invention may further include commonly known additives such as vulcanization accelerators, vulcanization activators, process oils, anti-aging agents, etc., if necessary, and the content of the additives is determined by the tire having the desired physical properties. It can be adjusted arbitrarily so that rubber can be obtained.

The vulcanization accelerator is not particularly limited as long as it is commonly known, and specifically, sulfoamide-based compounds, thiazole-based compounds, thiuram-based compounds, thiourea-based compounds, guanidine-based compounds, and/or dithiocarbamic acid-based compounds may be used. You can.

The sulfoamide-based compounds specifically include cyclohexylbenzothiazolyl sulfoamide, N-tert-butyl-2-benzothiazolyl sulfoamide, N,N-dicyclohexyl-2-benzothiazolyl sulfoamide, and N-oxo. It may include at least one member selected from the group consisting of cydiethylene-2-benzothiazolyl sulfoamide and N,N-diisopropyl-2-benzothiazolyl sulfoamide.

The thiazole-based compound specifically includes 2-mercaptobenzothiazole, sodium salt of 2-mercaptobenzothiazole, zinc salt of 2-mercaptobenzothiazole, copper salt of 2-mercaptobenzothiazole, 2 -cyclohexylamine salt of mercaptobenzothiazole, a group consisting of 2-(2,4-dinitrophenyl)mercaptobenzothiazole and 2-(2,6-diethyl4-morpholinothio)benzothiazole It may include one or more types selected from.

The thiuram-based compounds specifically include tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetramethylthiuram monosulfide, dipentamethylenethiuram disulfide, dipentamethylenethiuram monosulfide, and dipentamethylenethiuram tetrasulfide. , dipentamethylenethiuramhexasulfide, tetrabutylthiuramdisulfide, and pentamethylenethiuramtetrasulfide.

The thiourea-based compound may specifically include one or more selected from the group consisting of diethylthiourea, dibutylthiourea, trimethylthiourea, and diorthotolylthiourea.

The guanidine-based compound may specifically include one or more selected from the group consisting of diphenylguanidine, diorthotolylguanidine, triphenylguanidine, and diphenylguanidine phthalate.

The dithiocarbamate-based compounds specifically include zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, Zinc butyldithiocarbamate, zinc diamyldithiocarbamate, zinc dipropyldithiocarbamate, zinc hexadecylisopropyldithiocarbamate, zinc octadecylisopropyldithiocarbamate, zinc dibenzyldithiocarbamate and sodium diethyldithiocarbamate.

The vulcanization activator is not particularly limited as long as it is commonly known, and specifically, an inorganic vulcanization activator and/or an organic vulcanization activator can be used.

The inorganic vulcanization activator is specifically selected from the group consisting of zinc oxide, zinc carbonate, magnesium oxide, lead oxide, and potassium hydroxide. It may include more.

The organic vulcanization activator may specifically include one or more selected from the group consisting of stearic acid, zinc stearate, palmitic acid, linoleic acid, oleic acid, lauric acid, and dibutyl ammonium oleate.

The process oil is not particularly limited as long as it is commonly known, and specifically, paraffinic oil, naphthenic oil, aromatic oil and/or vegetable oil can be used.

The anti-aging agent is not particularly limited as long as it is commonly known, and specifically, amine-based compounds, phenol-based compounds, quinoline-based compounds, imidazole-based compounds, carbamic acid metal salts, and/or waxes can be used.

The rubber composition for tires according to the present invention can be manufactured through commonly known methods. Specifically, the raw rubber, the reinforcing agent, the silane coupling agent, and the additives are placed in a mixer and mixed to obtain a blend, and then the vulcanizing agent is added and the mixture is heated to 140 to 170° C. (specifically, 150 to 165° C., or 155 to 165° C. It can be prepared through a process of vulcanization at a temperature of ℃) for 10 to 30 minutes (specifically, 10 to 20 minutes, or 15 to 20 minutes).

tire

The present invention provides a tire manufactured using the above-described tire rubber composition. Specifically, the present invention provides a tire including a tread manufactured from the above-described tire rubber composition.

As the tread is manufactured using the above-described tire rubber composition, it can exhibit high tensile strength and excellent abrasion resistance while exhibiting the required level of elongation. Therefore, the tire according to the present invention including the tread may have excellent fuel efficiency (long-term performance).

The tire according to the present invention can be applied to automobile tires, bus tires, truck tires, aircraft tires, or motorcycle tires.

Hereinafter, the present invention will be described in more detail through the following examples and test examples. However, the following examples and test examples are merely examples for carrying out the present invention and are not intended to limit the scope of protection of the present invention.

<Manufacture of rubber composition for tires>

[Examples 1 to 5 and Comparative Example 1]

The components and contents of the composition shown in Table 1 (unit: parts by weight) were added to a mixer and vulcanized at 160°C for 15 minutes to prepare a rubber specimen.

ingredient Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 raw rubber SBR rubber 75 75 75 75 75 75 BR rubber 25 25 25 25 25 25 adjuvant carbon black
(Iodine adsorption value: 140g/kg, DBP adsorption value: 130ml/100g) 5 5 5 5 5 5 silica
(BET surface area: 200㎡/g) 100 100 100 100 100 100 Silane coupling agent Silane ¹⁾ 8 6 4 2 - 10 Urea adduct silane of formula 2 2 4 6 8 10 - Vulcanization activator zinc oxide 1.5 1.5 1.5 1.5 1.5 1.5 stearic acid One One One One One One Traction enhancer AMS (Alpha Methyl Styrene) resin 10 10 10 10 10 10 vulcanizing agent N-Sul ²⁾ 1.5 1.5 1.5 1.5 1.5 1.5 Vulcanization accelerator CZ ³⁾ 2 2 2 2 2 2 DPG ⁴⁾ 2 2 2 2 2 2 main)
1) Si69, Evonik company
2) MIDAS-101, Miwon Chemical
3) Cyclohexyl Benzothiazol Sulfenamide, Flexsis
4) Diphenyl Guanidine, Akrochem

[Test Example 1] Mooney viscosity measurement

Using Myongji Industrial's MOONEY VISCOMETER, the pattern viscosity of the unvulcanized rubber composition was measured according to ASTM D1646-04 standards, and the results are shown in Table 2 below.

[Test Example 2] Dynamic physical property evaluation

Dynamic properties were evaluated according to ASTM D-2231-87 standard, and the results are shown in Table 2 below.

[Test Example 3] Wear resistance evaluation

Abrasion resistance was evaluated by conducting a DIN (Din Abrasion) abrasion test according to the DIN 53516 standard using Ueshima's Din Abrasion tester, and the results are shown in Table 2 below.

The result values shown in Table 2 below are values converted when the physical property test results of Comparative Example 1 are set to 100, and the higher the result value, the improved the physical properties are.

division Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 pattern viscosity ML 1+4@100℃ 100 101 104 110 112 100 dynamic physical properties tensile strength 105 109 112 115 121 100 Elongation at brake 99 99 97 95 93 100 wear resistance Din wear 101 101 102 104 105 100

Referring to Table 2, Examples 1 to 5 to which a urea adduct silane compound was applied had a lower viscosity than Comparative Example 1 to which a conventional silane compound was applied (the content of the urea adduct silane compound increased). (the lower the viscosity), it can be seen that the processability is excellent. It can also be confirmed that the rubber specimens of Examples 1 to 5 exhibit dynamic physical properties and wear resistance that are equal or better than those of the rubber specimen of Comparative Example 1.

In particular, in the case of Examples 1 to 5, it was confirmed that the reversible reaction of the urea adduct silane compound occurred at 100 ° C., where viscosity is measured, and that the effect of lowering the viscosity of the tire rubber composition before vulcanization occurred. It can be seen that a rubber composition for tires meeting the purpose of the present invention was obtained.

Claims (5)

raw rubber; adjuvant; vulcanizing agent; And a silane coupling agent,
A rubber composition for tires, wherein the silane coupling agent includes a urea adduct silane compound containing a urea group and a sulfide group.
According to claim 1,
A rubber composition for tires, wherein the urea addition silane compound is a compound represented by the following formula (1):
[Formula 1]

In Formula 1,
R ₁ is each independently an alkoxy group having 1 to 4 carbon atoms,
R ₂ is each independently selected from the group consisting of an alkyl group having 1 to 5 carbon atoms and an alkoxy group having 1 to 4 carbon atoms.
According to claim 2,
A rubber composition for tires, wherein the urea addition silane compound is a compound represented by the following formula (2):
[Formula 2]

According to claim 1,
A rubber composition for a tire, comprising 1 to 15 parts by weight of the silane coupling agent based on 100 parts by weight of the raw rubber.
A tire comprising a tread made from the rubber composition for tires according to any one of claims 1 to 4.