KR100635613B1 - Tire tread rubber composition with improved wear resistance - Google Patents

Abstract

The present invention relates to a tire tread rubber composition having improved abrasion resistance, and more particularly, to a tire tread rubber composition which can improve wear resistance by including molybdenum disulfide in a conventional tire tread rubber composition.

An object of the present invention is to provide a tire tread rubber composition in which a tire tread rubber composition can include molybdenum disulfide to improve wear resistance.

In another aspect, the present invention is to provide a tire comprising a rubber made of the rubber composition as a tread.

The tire tread rubber composition of the present invention may include 1 to 5 parts by weight of molybdenum disulfide based on 100 parts by weight of the raw material rubber in the tire tread rubber composition.

Description

Tire tread rubber composition for improved anti-abrasion property

The present invention relates to a tire tread rubber composition having improved abrasion resistance, and more particularly, to a tire tread rubber composition which can improve wear resistance by including molybdenum disulfide in a conventional tire tread rubber composition.

Tire tread is made of natural rubber or natural rubber and synthetic rubber as main raw materials, and reinforcing materials, anti-aging agents, softeners, vulcanizing agents and vulcanization accelerators are appropriately selected in order to improve physical properties and other properties of raw rubber.

In the tire, the tread is a part of the vehicle which is in direct contact with the ground as the vehicle moves, and thus, the tread portion is gradually worn out due to the friction between the tire and the ground and the heat generated by the friction, so the abrasion resistance and the heat resistance should be excellent. .

In addition to the wear resistance and heat resistance, the vehicle should rotate in a curved line as well as go straight, so the rolling resistance of the tire should be good according to the rotation of the vehicle. In addition, since the road surface gets wet due to rain or the road surface is often wetted by freezing or ice generated during the winter, the wet traction of the tire on the wet road surface should be excellent.

The demands of today's tires are so diverse that there is a need for technology to properly control all characteristics such as steering stability, noise, straightness, rolling resistance, braking force, abrasion resistance and heat resistance.

Among them, abrasion resistance is in line with the basic performance of tires and the demands of consumers for the improvement of wear performance are increasing, especially in the current situation where resource saving and green round are becoming a global concern. Research and development to solve this situation is actively being promoted.

In order to improve abrasion resistance of a tire, there is a method of changing raw rubber or using a reinforcing agent.

First, the method using raw rubber is as follows. Conventionally, styrene butadiene rubber (SBR) or / butadiene rubber (BR) prepared by solution polymerization using a tin (Sn) polymer or a neodymium (Nd) polymer is added to the raw material rubber, or an amine Solution-polymerized styrene butadiene rubber (S-SBR) modified with aromatic vinyl or aromatic vinyl, or solution-polymerized styrene butadiene rubber (S-SBR) modified with hydroxy or silane ) Is added to the raw material rubber to improve the workability and dispersibility of carbon black and silica, which are reinforcing materials, according to the change of rubber microstructure.

In addition, by using a reinforcing material, carbon black having a high structure and high surface area is applied, or carbon black surface-treated with silicon (Si), or dispersions are different. There is a method using dual carbon black.

Recently, silica is used instead of carbon black as a reinforcing material. Therefore, silica coated with silane, silica coated with styrene butadiene rubber, or clay mixed with silica is used as a reinforcing material. It is used to improve wear resistance.

In addition, to improve the abrasion resistance of the tire tread rubber, using a norbonylsilicon coupling agent (coupling agent) to improve the abrasion resistance by improving the bonding strength of carbon black or silica with the rubber composition, or aluminum hydroxide (Aluminium hydroxide) There is also a technique to apply nano-size carbon black or clay using.

However, the above-mentioned techniques are effective only when some or all of the rubber or reinforcing material, which is the main material of the rubber composition, is effective. Therefore, in addition to the wear resistance of the rubber composition to be improved, other performances may be reduced or the physical properties may be reduced. In addition, there is a problem that the price of the improved rubber composition is too high to apply.

In order to solve the above-mentioned problems, the conventional tire tread rubber composition includes molybdenum disulfide to improve the wear resistance while maintaining the rotation resistance and braking force characteristics equivalent to those of the conventional tire tread rubber composition. It has been found that a tire tread rubber composition can be obtained.

 Accordingly, an object of the present invention is to provide a tire tread rubber composition in which a tire tread rubber composition may include molybdenum disulfide to improve wear resistance.

In another aspect, the present invention is to provide a tire comprising a rubber made of the rubber composition as a tread.

The tire tread rubber composition of the present invention for achieving the above-mentioned object may include 1 to 5 parts by weight of molybdenum disulfide based on 100 parts by weight of the raw material rubber in the tire tread rubber composition.

In the present invention, the raw material rubber can be used as long as it can be used as the raw material rubber of the conventional tire tread rubber composition.

In the present invention, as the raw material rubber of the tire tread rubber composition, natural rubber and synthetic rubber may be used alone, or mixed rubber in which the natural rubber and the synthetic rubber are mixed in a ratio of 1: 9 to 9: 1, or two or more of them. The mixed rubber which mixed the synthetic rubber can be used.

The synthetic rubber may be any one or more selected from styrene butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), chloroprene rubber (CR), nitrile rubber (NBR), and butyl rubber.

In the tire tread rubber composition of the present invention, molybdenum disulfide may be used in an amount of 1 to 5 parts by weight based on 100 parts by weight of the raw material rubber.

When the molybdenum disulfide is used in less than 1 part by weight based on 100 parts by weight of the raw material rubber in the tire tread rubber composition for trucks and buses of the present invention, the wear resistance is difficult to improve, and the molybdenum disulfide is more than 5 parts by weight based on 100 parts by weight of the raw material rubber. There is no improvement in the effect on wear resistance, there is a fear that the rotational resistance and braking force characteristics decrease.

Therefore, the tire tread rubber composition of the present invention preferably uses 1 to 5 parts by weight of molybdenum disulfide based on 100 parts by weight of the raw material rubber.

Molybdenum disulfide used to improve wear resistance in the present invention may be used as long as it can play such a role.

In the present invention, as an example of such molybdenum disulfide, MOS ₂ is 98.5% or more, molecular weight is 160.08, density is 4.7-4.8 g / cm ³ , hardness is 1-1.5, melting point is 1900 ° C., average particle diameter (D50) is 2 Μm or less, More preferably, an average particle diameter (D50) of 0.5-2 micrometers can be used.

In the tire tread rubber composition of the present invention, the reinforcing material may be used alone or in combination with carbon black and silica, respectively.

In the present invention, the reinforcing material may be used as long as it can be used as a reinforcing material of the conventional tire tread rubber composition.

As an example of the carbon black that can be used as a reinforcing material in the present invention, 30 to 60 parts by weight of iodine adsorption and 70 to 125 cc / mg of DBP adsorption may be used based on 100 parts by weight of the raw material rubber.

In addition, as an example of silica that can be used as a reinforcing material in the present invention, silica has a BET value of 100 to ²⁰⁰ m ² / g and a DBP adsorption amount indicating a structure of 100 to 250 ml / 100 g based on 100 parts by weight of the raw material rubber. 30 to 60 parts by weight can be used.

The present invention applies the above-mentioned raw rubber, molybdenum disulfide, reinforcing material of various properties, content of raw rubber, molybdenum disulfide, reinforcing material to the tire tread rubber composition, to achieve the object of the present invention mentioned above It is advisable to use specific properties, content of raw rubber, molybdenum disulfide and reinforcement.

According to the present invention, various additives such as activators, softeners, process oils, vulcanizing agents, and vulcanization accelerators, which are used in conventional tire tread rubber compositions, in addition to the above-mentioned raw rubbers, molybdenum disulfides, and reinforcing materials are appropriately selected as necessary. Can be used as However, these are general components used in conventional tire tread rubber compositions and are not essential components of the present invention.

On the other hand, the present invention includes a tire containing the rubber made of the tire tread rubber composition as a tread. In this case, the tire represents any one tire selected from a tire for a passenger car, a tire for a bus, a tire for a truck, and a tire for an aircraft.

Hereinafter, the present invention will be described by the following comparative examples, examples and test examples. However, these are not limited to the scope of the present invention by these as an embodiment of the present invention.

Comparative Example

45 parts by weight of silica (Zeosil, Rhodia Silica Korea), silane coupling agent (X-50S) based on 100 parts by weight of raw material rubber consisting of 90 parts by weight of emulsion-polymerized styrene butadiene rubber (SBR-1721, Kumho Petrochemical) and 10 parts by weight of natural rubber , shuguang) 7.2 parts by weight, carbon black (N-103, Korea carbon black) 45 parts by weight, process oil (Aromatic-2) 4 parts by weight, zinc oxide (ZnO) 3 parts by weight, stearic acid (2) by weight , 5 parts by weight of an anti-aging agent (N- (1,3-Dimethylbutyl)-N'-phenyl-p-phenylene diamine, Kumanox-13) and 2 parts by weight of wax are placed in a Banbury mixer, mixed at 150 ° C. for 30 minutes, and released. It was.

Then, 1.9 parts by weight of sulfur as a vulcanizing agent and 2.5 parts by weight of N-butylbenzothiazole sulfenamide (NS) as a vulcanization accelerator were added to the above formulation and vulcanized at 160 ° C. for 20 minutes to prepare a rubber. .

Comparative Example 2

In Banbury mixer, 0.5 parts by weight of molybdenum disulfide (MoS ₂ ) is added to the raw material rubber with silica, silane coupling agent, carbon black, process oil, zinc oxide, stearic acid, antioxidant and wax. Rubber was manufactured in the same manner as in Comparative Example 1.

Comparative Example 3

Except for adding 7 parts by weight of molybdenum disulfide (MoS ₂ ) to the raw material rubber, silica, silane coupling agent, carbon black, process oil, zinc oxide, stearic acid, anti-aging agent and wax in the Banbury mixer. Rubber was manufactured in the same manner as in Comparative Example 1.

<Example>

3 parts by weight of molybdenum disulfide (MoS ₂ ) based on 100 parts by weight of the raw material rubber consisting of 90 parts by weight of emulsion-polymerized styrene butadiene rubber (SBR-1721, Kumho Petrochemical) and 10 parts by weight of natural rubber, silica (Zeosil, Rhodia) Silica Korea) 45 parts by weight, silane coupling agent (X-50S, shuguang) 7.2 parts by weight, carbon black (N-103, Korea carbon black) 45 parts by weight, process oil (Aromatic-2) 4 parts by weight, zinc oxide ( ZnO) 3 parts by weight, stearic acid 2 parts by weight, anti-aging agent (N- (1,3-dimethylbutyl)-N'-phenyl-p-phenylene diamine, Kumanox-13) 5 parts by weight, wax 2 parts by weight The mixture was placed in a Banbury mixer, blended at 150 ° C. for 30 minutes, and then discharged.

Then, 1.9 parts by weight of sulfur as a vulcanizing agent and 2.5 parts by weight of N-butylbenzothiazole sulfenamide (NS) as a vulcanization accelerator were added to the above formulation and vulcanized at 160 ° C. for 20 minutes to prepare a rubber. .

Table 1. Compositions of Examples and Comparative Examples Rubber (Unit: parts by weight)

Item Comparative Example 1 Comparative Example 2 Comparative Example 3 Example SBR-1721 90 90 90 90 Natural Rubber (1) 10 10 10 10 MoS ₂ (2) - 0.5 7 3 Silica 45 45 45 45 Silane coupling agent 7.2 7.2 7.2 7.2 Carbon black 45 45 45 45 Process oil 4 4 4 4 Zinc oxide 3 3 3 3 Stearic acid 2 2 2 2 Anti-aging 5 5 5 5 Wax 2 2 2 2 Vulcanizing agent 1.9 1.9 1.9 1.9 Vulcanization accelerator 2.5 2.5 2.5 2.5

(1) SMR-20 (Standard Malaysian Rubber-20)

(2) Molybdenum disulfide (Molybdenum disulfide): MOS ₂ is 98.5% or more, molecular weight 160.08, density 4.7-4.8 g / cm ³ , hardness 1-1.5, melting point 1900 ° C., average particle diameter (D50) 2 Is less than or equal to μm.

<Test Example>

Physical properties such as exothermic test, Mooney test, rheometer, exothermic test, abrasion test, Leobibron test were measured according to ASTM-related regulations for the rubbers of Examples and Comparative Examples, and the results are shown in Table 2 below.

Table 2. Physical Properties of Examples and Comparative Examples Rubber

Item Comparative Example 1 Comparative Example 2 Comparative Example 3 Example Mooney viscosity (125 ℃) Viscosity 69 72 79 77 Scotch time (minutes) 21.4 21.1 28.4 28.3 Rheometer (160 ℃) Torque 35.6 34.4 31.9 31.9 Vulcanization time (T90, min) 10.8 10.4 13.2 12.4 Tensile Properties Hardness 71 72 72 71 300% modulus (kgf / cm ² ) 128 130 132 157 Tensile strength (kgf / cm ² ) 177 175 177 183 Elongation (%) 367 369 371 350 Fever test Fever (℃) 38.4 37.8 37.6 37.2 Abrasion test (loss) (1) DIN wear (g) 0.151 0.150 0.148 0.135 PICO Wear (g) 0.032 0.034 0.031 0.021 Leobibronn examination (2) Tanδ (70 ° C) 0.495 0.473 0.477 0.476 Tanδ (0 ℃) 0.206 0.194 0.199 0.204

(1) Abrasion test (PICO wear, DIN wear) shows the wear value of the specimen, the lower the value, the better the wear resistance.

(2) During the Leobibron test, Tan δ (70 ℃) is a value that can predict rolling resistance characteristics of tire performance. The lower the value, the better, and Tan δ (0 ℃) is wet during tire performance. It is a predictable value of wet traction characteristics. The higher the value, the better.

As can be seen from the results of the test example, the rubber of the example containing an appropriate amount of molybdenum disulfide showed a dramatic improvement in abrasion resistance and braking resistance, compared to the rubber of the comparative example containing no molybdenum disulfide. have.

On the other hand, the rubber of Comparative Examples 2 and 3, which did not add the molybdenum disulfide in an appropriate content, it can be seen that the wear resistance is not improved compared to the comparative rubber, the rotational resistance characteristics and braking force characteristics are reduced.

Therefore, the tire tread rubber composition of the present invention is preferably used in an appropriate amount of 1 to 5 parts by weight based on 100 parts by weight of the raw rubber.

As described above, although described with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and modified within the scope of the present invention without departing from the spirit and scope of the invention described in the claims below. It will be appreciated that it can be changed.

Claims (3)

In the tire tread rubber composition, A tire tread rubber composition having improved wear resistance, comprising 1 to 5 parts by weight of molybdenum disulfide based on 100 parts by weight of raw rubber. The molybdenum disulfide according to claim 1, wherein the molybdenum disulfide has a MOS ₂ of 98.5% or more, a molecular weight of 160.08, a density of 4.7-4.8 g / cm ³ , a hardness of 1-1.5, a melting point of 1900 ° C., and an average particle diameter (D50) of 2 μm. Tire tread rubber composition with improved wear resistance, characterized in that below. A tire comprising a rubber made of the rubber composition of claim 1 as a tread.