KR100233226B1 - A rubber composition of tire tread with lower fuel consumption property - Google Patents

Abstract

The present invention relates to a rubber composition for a low fuel consumption tire tread, using a rubber having a glass transition temperature of -50 to -10 ° C, and at the same time carbon black and silica and cashew modified phenolic resin having a small particle diameter and / or development; Or a rubber composition for low fuel consumption tire tread using cashew oil.

According to the present invention, it is possible to provide a rubber composition for a low fuel consumption tire tread having a low manufacturing cost while improving both the braking performance on the wet road surface and the fuel efficiency performance due to the rotational frictional resistance with the road surface.

Description

Rubber composition for low fuel consumption tire tread

The present invention relates to a rubber composition for a low fuel consumption tire tread, and more particularly, using a rubber having a glass transition temperature of -50 to -10 ° C, and at the same time, carbon black, silica and cashew modified with a small particle size and developed structure. It is a rubber composition for low fuel consumption tire tread using a phenol resin and / or cashew oil.

In the case of a tread rubber composition used in a conventional low fuel efficiency tire, it is known that it is very difficult to simultaneously improve braking performance and wear resistance on wet road surfaces with low fuel efficiency.

In order to solve the problem of low braking performance on wet roads, conventionally, the use of carbon black or the use of rubber with high glass transition temperature improved the braking performance on wet roads while partially sacrificing low fuel economy. . And in order to solve the problem of low wear resistance, butadiene rubber or carbon black was increased. However, the use of butadiene rubber causes a problem that the braking performance on the wet road surface is deteriorated, the increase in the carbon black has a problem of low fuel economy performance.

The present inventors have studied to solve the problems of the prior art as described above, using a rubber having a glass transition temperature of -50 to -10 ℃, and at the same time, carbon black and silica and cashew with a small particle size and advanced structure When the modified phenol resin and / or cashew oil is used, it has been found that the manufacturing cost can be reduced while improving both the braking performance on the wet road surface and the fuel efficiency performance by the rotational friction resistance with the road surface.

Accordingly, an object of the present invention is to provide a rubber composition for a low fuel consumption tire tread, which is also improved in braking performance on a wet road surface and fuel economy performance due to rotational frictional resistance with the road surface, while also reducing manufacturing costs.

The present invention relates to 100 parts by weight of the total rubber component containing 30 to 100 parts by weight of styrene-butadiene rubber having a glass transition temperature of -50 to -10 ° C, and the DBP absorption amount is 115 to 145 ml / g, and the nitrogen adsorption ratio 5 to 50 parts by weight of carbon black having a surface area of 117 to 137 ml / g, 10 to 60 parts by weight of silica, 2 to 10 parts by weight of cashew modified phenolic resin and / or cashew oil, hexamethylenetetraamine or hexamethoxymethylmelanin 1 to 5 parts by weight, 0.1 to 20 parts by weight of the silane coupling agent, 10 to 40 parts by weight of petroleum oil, and additives used in the conventional low fuel consumption tread rubber composition, characterized in that the rubber composition for low fuel consumption tread to be.

Hereinafter, the present invention will be described in detail.

In the present invention, 30 to 100 parts by weight of styrene-butadiene rubber having a glass transition temperature of -50 to -10 ° C is used. By using 30 parts by weight or more of a rubber having a glass transition temperature of -50 to -10 ° C, it is possible to increase braking performance on wet road surfaces. As the styrene-butadiene rubber used in the present invention, any styrene-butadiene rubber having a glass transition temperature of -50 to -10 ° C can be used.

The rubber component of the present invention may contain natural rubber, which is used to improve the tearing phenomenon when leaving the mold immediately after the tire vulcanization, and it is not necessary to use the sectional mold to improve the tearing phenomenon.

In the present invention, 5 to 50 parts by weight of carbon black having a DBP oil absorption of 115 to 145 ml / g and a nitrogen adsorption specific surface area of 117 to 137 ml / g is used as the reinforcing agent. Such carbon black has a small particle size and a developed structure, and may increase wear resistance. In addition, silica and cashew modified phenolic resins and / or cashew oils can be used to reduce the amount of carbon black used to improve braking performance on wet roads while maintaining low fuel efficiency at the level of conventional low fuel efficiency rubber compositions.

Cashew modified phenol resin and cashew oil used in the present invention is a composite based on cashew nut cell oil, the molecular weight of the cashew modified phenol resin is 400 to 1500, the cashew oil has an average molecular weight of 300 to 1000, molecular weight distribution of 1.5 to 5.0 and a degree of polymerization of 1 to 5.

Silica used in the present invention is a powder or granule in the form of nitrogen adsorption specific surface area of 150 to 190 m 2 / g, CTAB of 150 to 190 m 2 / g using 10 to 60 parts by weight, cashew modified phenol resin and / or Cashew oil is preferably used in an amount of 2 to 10 parts by weight.

In addition, in the present invention, in order to solve the problem that the hardness increases with the use of cashew modified phenol resin and / or cashew oil, petroleum oil, which is a softener used in a conventional rubber composition, is increased. Increasing the use of petroleum oil is accompanied by the effect of reducing the raw material cost of the rubber composition. Petroleum oil uses 10 to 40 parts by weight, preferably 20 to 30 parts by weight.

In the present invention, 1 to 5 parts by weight of hexamethylenetetraamine or hexamethoxymethylmelanin as a vulcanizing agent is used, and 0.1 to 20 parts by weight of a silane coupling agent capable of reacting with rubber and silica at the same time. Examples of the silane coupling agent that can be used include mercapto propyl triethoxy silane or a silane coupling agent sold under the trade name X50S.

Hereinafter, the present invention will be described in more detail with reference to Examples. The present invention is not limited to the following Examples.

Example

Examples 1 to 3

To prepare a rubber composition for a low fuel consumption tire tread as shown in Table 1. After the specimens were prepared from the obtained rubber composition, each of Examples 1 to 3 was used, and the 0 ° C G ″ value, the 60 ° C Tanδ value, the wear resistance, and the hardness were measured.

The 0 ° C G ″ and 60 ° C Tanδ values were measured at 0.5% strain at 10 Hz frequency using a torsion type viscoelastic tester by a temperature sweep method.

The abrasion resistance was measured by a rambon abrasion tester, which is an indoor abrasion tester, and the higher the relative comparison value in the test, the more abrasion resistance is favorable.

Hardness was measured with a Shore A type durometer at room temperature 20 ℃.

Comparative Example 1

To prepare a rubber composition for low fuel consumption tire tread as shown in Table 1. After the specimen was prepared from the obtained rubber composition, the 0 ° C. G ″ value and the 60 ° C. Tanδ value, abrasion resistance and hardness were measured in the same manner as in Example 1.

(Unit: parts by weight) Example 1 Example 2 Example 3 Comparative Example 1 Natural rubber 10 10 - 40 SBR1502 40 40 40 20 Rubber ① / ② -/ 50 -/ 50 -/ 60 40 /- Carbon Black ① / ② -/ 40 -/ 40 -/ 35 55 /- Silica 15 15 25 - Petroleum oil 21 24 30 3 Cashew Modified Phenolic Resin - 2 One - Cashew Modified Phenolic Oil 6 - 3 - Sulfur / HMTA / X50S / Accelerator 1.8 / 0.6 / 2.4 / 1.2 1.8 / 0.2 / 2.4 / 1.2 1.8 / 0.4 / 4.0 / 1.2 1.7 /-/-/ 0.8 Hardness 65 65 65 63 0 ℃ G " 4,793E + 7 4,414E + 7 4,931E + 7 1,251E + 7 60 ℃ Tanδ 0.1458 0.1521 0.1557 0.1610 Elongation / Tensile Strength (at Brake) 512/213 485/202 524/211 534/219 Wear Resistance (Index) 109 107 108 100 Price ￦ / ℓ (index) 95 94 96 100

-Carbon black ⓛ: DBP oil absorption 100-120 ㎖ / 100g, nitrogen adsorption specific surface area 86-106 ㎡ / g

-Carbon black ②: DBP oil absorption 115-145 ㎖ / 100g, nitrogen adsorption specific surface area 117-137 ㎡ / g

-SBR1502: Emulsion polymerization styrene-butadiene rubber (SBR) with 23.5% styrene bond

Rubber (1): A solution polymerization SBR in which the amount of styrene bonds is 15% and the amount of vinyl bonds in the butadiene portion is 57%.

Rubber (2): solution polymerization SBR having a styrene bond of 20% and a vinyl bond of 60% of butadiene.

Silica: Nitrogen adsorption specific surface area 150-190 m 2 / g, CTAB 150-190 m 2 / g powder or granule form (CTAB is cetyl trimethyl ammonium bromide, C ₁₆ H ₃₃ (CH ₃ ) ₃ NHBr) To measure the surface area of carbon black particles)

HMTA: Hexamethylenetetraamine

As can be seen from the results of Table 1, when the amount of carbon black is reduced and silica and cashew modified phenol resins and / or cashew oils are used, 60 ° C. Tanδ values related to tire low fuel consumption are compared with those of the conventional low fuel efficiency tread rubber composition. Using a rubber with a glass transition temperature of -50 to -10 ° C (rubber ②) at the same time while maintaining a lower or equivalent level, and using silica and cashew modified phenolic resins and cashew modified oils, The associated 0 ° C G "value could be increased. In addition, carbon black with a small particle size and a developed structure could be used to improve abrasion resistance. Petroleum oil may be used in a range that does not significantly affect other physical properties. Use at least 10 parts by weight to lower the hardness of cashew modified phenol resins and oils, It also lowered the price.

According to the present invention, a rubber having a glass transition temperature of -50 to -10 ° C is used in the rubber composition for low fuel efficiency tire tread, and at the same time, carbon black and silica and cashew modified phenol resin and / or cashew having a small particle diameter and developed structure By using oil, it is possible to reduce the manufacturing cost while also improving the braking performance on the wet road surface and fuel economy performance due to the rotational frictional resistance with the road surface.

Claims (3)

With respect to 100 parts by weight of the total rubber component containing 30 to 100 parts by weight of styrene-butadiene rubber having a glass transition temperature of -50 to -10 ° C, the DBP absorption is 115 to 145 ml / g and the nitrogen adsorption specific surface area is 117 5 to 50 parts by weight of carbon black, which is from 137 ml / g, 10 to 60 parts by weight of silica, 2 to 10 parts by weight of cashew modified phenol resin and / or cashew oil, hexamethylenetetraamine or hexamethoxymethylmelanin 1 to 5 A rubber composition for low fuel efficiency tire treads, comprising an additive used in parts by weight, 0.1 to 20 parts by weight of a silane coupling agent, 10 to 40 parts by weight of petroleum oil, and a conventional low fuel efficiency tire tread. The rubber composition for low fuel consumption tire tread according to claim 1, wherein the diene rubber having a glass transition temperature of -50 to -10 ° C is used instead of styrene-butadiene having a glass transition temperature of -50 to -10 ° C. The rubber composition according to claim 1, wherein the silica has a nitrogen adsorption specific surface area of 150 to 190 m 2 / g and a CTAB of 150 to 190 m 2 / g.