KR102460721B1 - Tyre tread rubber and tire by using it - Google Patents

Abstract

The present invention relates to a rubber composition for tire tread and a tire thereof. The rubber composition for tire tread and the tire according to the present invention comprise: raw rubber; silica; and a silane coupling agent. The silane coupling agent is a compound represented by the chemical formula (1) below, wherein while maintaining the physical properties of the existing tire, the scorch time is shortened due to the strong and fast reaction of the existing mercaptosilane with the polymer, thereby preventing a decrease in processability and reinforcing properties. [Chemical formula 1] In chemical formula 1, R1 is an alkyl group having 1 to 15 carbon atoms, R2 is a hydrocarbon group having 1 to 3 carbon atoms, R3 is an alkoxy group having 1 to 10 carbon atoms, R4 is a hydrocarbon group having 1 to 5 carbon atoms, and R5 is an alkyl group having 1 to 15 carbon atoms.

Description

Rubber composition for tire tread and tire thereof

The present invention relates to a rubber composition for a tire tread and a tire thereof, and more particularly, to a scorch time shortened due to a strong and rapid reaction of the existing mercaptosilane with a polymer while maintaining the physical properties of the existing tire, thereby reducing workability and reinforcing properties It relates to a rubber composition for a tire tread and a tire thereof.

A tire tread is a part that is in direct contact with the ground while the vehicle is moving, and must have excellent characteristics such as abrasion resistance, rolling resistance, and tensile strength that affect fuel efficiency.

Among the various additives used in the rubber composition used in these tire treads, carbon black was used as the main filler to improve abrasion resistance and tensile strength, but there were problems with low fuel efficiency and wet road braking performance. Instead of carbon black, silica was mainly used.

When silica as such a reinforcing agent is used in the tire rubber composition, there are advantages of improving wet road friction and reducing rolling resistance, but due to the strong polar group (-OH), miscibility with non-polar rubber is poor, and the It is known that the disadvantage is disadvantageous in terms of processing due to strong cohesive force.

In order to solve this problem, volatile organic compounds (VOCs) together with Si69 as a coupling agent for coupling between silica and rubber There is a trend to use mercaptosilane, which is excellent in reducing emission, improving dispersibility of fillers, and improving rotational resistance, heat generation properties and wear performance.

In conventional tire manufacturing, the heat treatment time required to reach the temperature at which the unvulcanized rubber composition is cured prior to the vulcanization process such as press work by compounding the rubber composition and then aging is called scorch time. If the scorch time is long, the shape of the rubber may collapse before the composition is vulcanized. Since vulcanization occurs during processing, plasticity decreases and elasticity increases, making the product impossible to process. Therefore, an appropriate scorch time is required for physical properties and processability.

In the case of the mercapto group (-SH) of the mercaptosilane, since the reactivity with the filler and the organic polymer is so high that it is known that the reactivity with the filler and the organic polymer is 100%,

It is not easy to use the mercaptosilane in manufacturing a filled elastomer, and the mercaptosilane is uncured and due to a short scorch time with the filled elastomer, Mixing with a polymer, extrusion of an uncured elastomer, and premature crosslinking or formation of a compound having a high viscosity have a problem in that the processability and reinforcing properties of the product are deteriorated.

Republic of Korea Patent Publication No. 1023239 (2011.03.10.) Republic of Korea Patent Publication No. 1539152 (2015.07.17.)

Therefore, the technical problem to be solved by the present invention is that, in a rubber composition using mercaptosilane, the scorch time is shortened due to the strong and rapid reaction of the existing mercaptosilane with the polymer while maintaining the physical properties of the existing tire. It is to provide a rubber composition for a tire tread that prevents deterioration of reinforcing properties, and a tire thereof.

In order to solve the above technical problem, the present invention provides a rubber composition for a tire tread, comprising raw rubber, silica, and a silane coupling agent, wherein the silane coupling agent is a compound represented by Formula 1 below.

<Formula 1>

(In Formula 1, R1 is an alkyl group having 1 to 15 carbon atoms, R2 is a hydrocarbon group having 1 to 3 carbon atoms, R3 is an alkoxy group having 1 to 10 carbon atoms, R4 is a hydrocarbon group having 1 to 5 carbon atoms, and R5 is a carbon number 1 to 15 alkyl groups)

According to another embodiment of the present invention, 1 to 15 parts by weight of the silane coupling agent may be used with respect to 100 parts by weight of the raw rubber.

According to another embodiment of the present invention, the silane coupling agent may be a compound represented by Formula 2 below.

<Formula 2>

Meanwhile, the present invention provides a tire comprising the above-described rubber composition for a tire tread.

According to the rubber composition for a tire tread and a tire thereof according to the present invention, the scorch time is shortened due to the strong and rapid reaction of the existing mercaptosilane with the polymer while maintaining the physical properties of the existing tire, thereby preventing the decrease in workability and reinforcing properties to perform

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

Hereinafter, examples will be given to help the understanding of the present invention be described in detail. However, the following examples are merely illustrative of the contents of the present invention and the scope of the present invention is not limited to the following examples.

The embodiments of the present invention are provided to more completely explain the present invention to those of ordinary skill in the art.

In addition, although the present invention will be described in detail, for those of ordinary skill in the art, it will be clear that these specific descriptions are only preferred embodiments, and the scope of the present invention is not limited thereby. , it will be said that the substantial scope of the present invention is defined by the appended claims and their equivalents.

The rubber composition for a tire tread according to the present invention includes raw rubber, silica, and a silane coupling agent, and the silane coupling agent is a compound represented by Formula 1 below.

<Formula 1>

In Formula 1, R1 is an alkyl group having 1 to 15 carbon atoms and more preferably 7 to 12 carbon atoms, R2 is a hydrocarbon group having 1 to 3 carbon atoms, R3 is an alkoxy group having 1 to 10 carbon atoms, more preferably 1 to may be 4, R4 is a hydrocarbon group having 1 to 5 carbon atoms, R5 is an alkyl group having 1 to 15 carbon atoms and more preferably 7 to 12 carbon atoms, if R1 and R5 exceed 16 carbon atoms, rather silica There may be a risk of deterioration of the physical properties of the rubber composition because the reaction is not smooth due to steric blocking.

In addition, the raw rubber may be natural rubber, synthetic rubber, or a mixture thereof, wherein the synthetic rubber is not particularly limited, and for example, styrene butadiene rubber, butadiene rubber, butyl rubber, emulsion polymerization styrene butadiene rubber ( E-SBR), solution polymerization styrene butadiene rubber (S-SBR), epichlorohydrin rubber, nitrile rubber, hydrogenated nitrile rubber, brominated polyisobutyl isoprene-co-paramethyl styrene BIMS) rubber, urethane rubber, fluorine rubber, silicone rubber, styrene ethylene butadiene styrene copolymer rubber, ethylene propylene rubber, ethylene propylene diene monomer rubber, hypalon rubber, chloroprene rubber, ethylene vinyl acetate rubber and acrylic rubber, etc. It may be at least one selected from the group.

In addition, the rubber composition for a tire may contain 1 to 15 parts by weight of a silane coupling agent as a reinforcing agent based on 100 parts by weight of the raw rubber, and if the content is less than 1 part by weight, there may be problems in fairness and rolling resistance characteristics, , Conversely, when it exceeds 15 parts by weight, not only the physical properties deteriorate, but also a problem may occur in the rotational resistance characteristics.

In addition, it is effective to use a silica having a BET surface area of 110 to 250 m 2 /g to react with a silane coupling agent, and silica having a surface treated with silanetriol may be used.

In addition, carbon black may be further included in addition to silica as a reinforcing agent, and it is preferable to use particles having a specific surface area of 140 m 2 /g or less for the carbon black in terms of dispersion and wear.

The rubber composition for a tread for a tire of the present invention may further include a vulcanizing agent. As the vulcanizing agent, it is possible to use an organic peroxide or a sulfur-based vulcanizing agent, and as the organic peroxide, for example, benzoyl peroxide, di cumyl 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)hexyne-3 or 1,3-bis(t-butylperoxy) oxypropyl)benzene, di-t-butylperoxy-diisopropylbenzene, t-butylperoxybenzene, 2,4-dichlorobenzoyl peroxide, 1,1-di-t-butylperoxy-3,3, 5-trimethylsiloxane, n-butyl-4,4-di-t-butylperoxyvalerate, etc. can be used.

Moreover, as a sulfur-type vulcanizing agent, sulfur, morpholine disulfide, etc. can be used, for example. Among these, sulfur is preferable. These vulcanizing agents may be used independently and may be used in combination of 2 or more type.

The rubber composition for a tire tread of the present invention may include conventional additives for rubber compositions, such as zinc oxide, stearic acid, antioxidants, and adhesives, and the content of the additives may be arbitrarily adjusted according to desired physical properties. .

The manufacturing method of the rubber composition for a tire of the present invention is prepared by mixing the raw material rubber, carbon black, silica, process oil, and additives such as a silane coupling agent in a Banbury mixer at a temperature of 135 to 165° C. according to a conventional method. Next, since it can be prepared including the step of vulcanization at 145 ~ 170 ℃ for 5 ~ 40 minutes, a detailed description of the manufacturing method will be omitted.

Meanwhile, the present invention provides a tire comprising the rubber composition for a tire tread, and the rubber composition for a tire tread may be employed in a tread portion of a tire.

The tire of the present invention is manufactured using the above-described rubber composition for a tire, and as long as it is a conventional tire manufacturing method within the scope of using the rubber composition, the tire of the present invention is not particularly limited. can be manufactured.

Hereinafter, the present invention will be described in more detail with reference to the following Examples and Experimental Examples. The following examples and experimental examples are merely examples for carrying out the present invention, and are not intended to limit the protection scope of the present invention.

Comparative Examples 1 and 2, Examples 1 to 3

The components and contents of the composition shown in Table 1 (unit: parts by weight) were added to a Banbury mixer and blended at 135° C. for 6 minutes to obtain a formulation.

Sulfur was added as a vulcanizing agent to the above formulation, and vulcanized at 160° C. for 15 minutes to prepare a rubber specimen.

Item Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Styrene Butadiene Rubber 70 70 70 70 70 butadiene rubber 30 30 30 30 30 silica 80 80 80 80 80 Silane coupling agent 1 8 - - - - Silane coupling agent 2 - 8 - - - Silane coupling agent 3 - - 8 12 Silane coupling agent 4 8 carbon black 5 5 5 5 5 zinc oxide 3 3 3 3 3 stearic acid 2 2 2 2 2 anti-aging agent 1.5 1.5 1.5 1.5 1.5 sulfur 1.5 1.5 1.5 1.5 1.5 DPG 2.0 CZ 2.0 2.0 2.0 2.0 2.0 TBzTD - 0.2 0.2 0.2 0.2

- Silane coupling agent 1 is a sulfide-based silane, TESPT

- Silane coupling agent 2 is a mercapto group silane, Si-363

- Silane coupling agent 3 is a compound represented by the following formula (2)

<Formula 2>

- Silane coupling agent 4 is a compound represented by the following formula (3)

<Formula 3>

<Experimental example>

For each rubber specimen prepared in Table 1 above, physical properties such as Mooney viscosity, tensile properties (Tensile), dynamic viscoelasticity (DMA), and abrasion (Din Abrasion) were measured according to ASTM-related regulations, and the results were measured It is shown in Table 2 below.

Item Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Mooney viscosity MV@100℃ 100 124 120 115 118 T05 15.3 7.9 12.8 14.0 11.5 MDR(180℃) T50 1.8 0.9 1.4 1.7 1.2 tensile properties HD's 72 70 74 69 63 300%-M 136 124 132 115 100 T.S. 162 188 205 187 165 E.B. 346 414 431 372 425 DMA Tg -7.0 -6.6 -6.3 -4.4 -4.5 tanδ0℃
(index) 0.675
(95) 0.710
(100) 0.719
(101) 0.739
(104) 0.745
(105) tanδ60℃
(index) 0.114
(69) 0.087
(100) 0.078
(110) 0.094
(92) 0.091
(95) Wear Loss,(g) 0.156
(104) 0.163
(100) 0.154
(106) 0.172
(94) 0.175
(93)

- Among the above Mooney viscosity, MV@100℃ is when mixing rubber is put between the upper and lower rotors with several grooves in the circumferential direction and rotated at 100℃, shear behavior is formed between the rotors and the resulting torque (rubber for rotating rotor) resistance), and the lower the viscosity value, the better the processability and processability.

- Among the above Mooney viscosity, MV@125°C means the minimum torque value of viscosity in the measurement of 125°C Mooney viscosity.

- Among the Mooney viscosity, T05 (Mooney scorch time) means the time (min) when ML + 5 units, and the ML means the time (min) when the viscosity has the minimum torque value at 5 ° C. Mooney viscosity measurement do.

- Hardness is a real value of a rubber specimen, measured according to ASTM standards, and the higher the value, the better the hardness.

- 300%-M (Modulus) is the tensile strength of a rubber specimen at 300% elongation, measured according to ASTM standards, and the higher the value, the better the tensile strength.

- T.S (tensil strength) is the value obtained by dividing the maximum tensile load until the specimen breaks in the tensile test of the material by the cross-sectional area of the specimen before the test. The larger the number, the better the tensile strength.

- E.B is the elongation ratio at which the material is stretched during the tensile test of the material. The larger the number, the better the elongation.

- Tg means the temperature at which the polymer branches of the polymer material are activated and start to move depending on the temperature.

- tanδ@ 0℃ is tandelta (tanδ℃, measured at 11Hz by a DMA (Dynamic Mechanical Analysis) tester), which is an index of braking performance, and is used as an index of wet road braking performance. It means excellent braking performance.

- tanδ@60℃ is tandelta (tanδ60℃), which is an index of rolling resistance, measured at 11Hz by a DMA (Dynamic Mechanical Analysis) tester, and is used as an index of rolling resistance performance. The lower the number, the more the rolling resistance It means excellent performance.

- DIN abrasion test is an evaluation item to predict tire wear, and the lower the number, the better the wear characteristics.

As shown in the results of Table 2, the rubber compositions (Examples 1 and 2) containing the silane prepared in Table 1 of the present invention as a silane coupling agent were compared with the conventional mercaptosilane (Comparative Example 2). , modulus and tensile strength (T.S) are similar, elongation (E.B) is better, tanδ°C, an index of braking performance, is equal, and tanδ60°C, an index of rolling resistance, and wear performance are improved.

In addition, it can be seen that the scorch time is longer compared to the existing mercapto silane, so that the workability is very improved.

From the above, it can be seen that the rubber composition for a tire tread according to the present invention is excellent in a rubber composition for a tire tread with improved processability, which is a major disadvantage of the conventional mercapto silane, and a tire using the same.

Claims (4)

Including raw material rubber, silica and silane coupling agent,
The rubber composition for a tire tread, characterized in that the silane coupling agent is a compound represented by Formula 1 below.
<Formula 1>

(In Formula 1, R1 is an alkyl group having 1 to 15 carbon atoms, R2 is a hydrocarbon group having 1 to 3 carbon atoms, R3 is an alkoxy group having 1 to 10 carbon atoms, R4 is a hydrocarbon group having 1 to 5 carbon atoms, and R5 is a carbon number 1 to 15 alkyl groups)
The method of claim 1,
A rubber composition for a tire tread, characterized in that 1 to 15 parts by weight of a silane coupling agent is used based on 100 parts by weight of the raw rubber.
The method of claim 1,
The rubber composition for a tire tread, characterized in that the silane coupling agent is a compound represented by Formula 2 below.
<Formula 2>

A tire comprising the rubber composition for a tire tread according to any one of claims 1 to 3.