KR100903990B1 - Sustainable Rubber composition for tire tread - Google Patents

Abstract

The present invention relates to an environment-friendly tire tread rubber composition, carbon black 60 to 80 parts by weight with respect to 100 parts by weight of the raw material rubber consisting of 70 to 90 parts by weight of emulsion polymerization styrene butadiene rubber and 10 to 30 parts by weight of neodymium butadiene rubber. , Eco-friendly tire tread rubber composition containing 1 to 10 parts by weight of environmentally friendly softener.

The rubber composition according to the present invention uses neodymium butadiene rubber having a sheath content of 98% or more, which is advantageous for abrasion performance, and is an oil of 3% by weight or less of polycyclic aromatic hydrocarbons as an environment-friendly softener for flexibility and processability. By using it, not only wear resistance but also braking performance and low fuel consumption are improved.

 Eco-Friendly * Treads * PAH * polycyclic aromatic hydrocarbons

Description

Eco-friendly tire treads {Sustainable Rubber composition for tire tread}

The present invention relates to an environmentally friendly tire tread rubber composition, and more particularly, using neodymium butadiene rubber (Nd-BR) having a cis content of 98% or more, and using polysia as an environmentally friendly softener for flexibility and processability. Polycyclic Aromatic Hydrocarbon (hereinafter referred to as PAH) is an environmentally friendly tire tread rubber composition using an oil of 3% by weight or less.

In general, it is known that blending butadiene rubber having a low glass transition temperature (Tg) may improve tire wear performance and fuel economy. However, there is a problem in that the braking performance is lowered and there is a limit in improving the wear performance.

If the amount of reinforcing filler is used to compensate for the decrease in braking performance, braking performance will be improved, but fuel efficiency will be disadvantageous.In order to improve tire wear performance, a small amount of carbon black with a small particle size or a large amount of carbon black with a large particle diameter will be added. If you do, respectively, it may cause deterioration of rubber properties due to dispersibility problems and deterioration of heat generation and durability due to the use of a large amount of reinforcing agents.

In order to overcome this problem, the application of new materials has been actively studied in recent years.

Meanwhile, in Europe, the demand for the use of environmentally friendly materials is increasing in relation to environmental regulations. There are many kinds of softeners among the additives of the tread rubber composition of a tire for a passenger car.

In general, aromatic oils are known to improve processability and achieve optimum physical properties in refining and extrusion processes.However, with the increase in environmental awareness, when the PAH content in aromatic oils is 3% by weight or more, it is highly likely to cause cancer. It is known that the European Rubber Association (BRIC) has accepted this result and has come up with countermeasures.In the EU, specific measures for use have been established, and when the total PAH content in oil is extracted by DMSO (Dimethylsulfoxide) extraction method, it is more than 3% by weight. By enacting a ban on sales after January 1, 2010, all tire manufacturers consider it an urgent problem to solve.

As mentioned above, the market demands the development of new materials and the use of eco-friendly materials for the performance improvement of tires at the same time, and technology for the discovery of eco-friendly materials and the improvement of tire performance using the same has been a hot topic in the industry recently.

In order to solve the above problems, an object of the present invention is to provide an eco-friendly tire tread rubber composition that improves abrasion resistance, braking performance and low fuel efficiency of a tire while using an eco-friendly softener.

In order to achieve the above object, the present invention relates to 100 parts by weight of raw material rubber consisting of 70 to 90 parts by weight of emulsion polymerization styrene butadiene rubber and 10 to 30 parts by weight of neodymium butadiene rubber, carbon black 60 to 80 parts by weight, environmentally friendly It provides an environmentally friendly tire tread rubber composition comprising 1 to 10 parts by weight of a softener.

The eco-friendly tire tread rubber composition of the present invention uses 70 to 90 parts by weight of an emulsion-polymerized styrene butadiene rubber obtained by lubricating oil having an environmentally-friendly property in the emulsion-polymerized styrene butadiene as a raw material rubber.

If the content is less than 70 parts by weight, there is a problem that the wet braking performance is reduced, and if it exceeds 90 parts by weight, there is a problem that the wear performance is reduced.

In addition, butadiene rubber used in the present invention as a raw material rubber is a butadiene rubber using a neodymium catalyst, the cis content is 98% or more, has a low glass transition temperature between -105 ~ -110 ℃ and a molecular weight distribution of 2.1 ~ 3.1 It has sharp characteristics, preferably 10 to 30 parts by weight.

Carbon black is preferably nitrogen adsorption specific surface area 110 ~ 130 m ² / g, DBP oil absorption 110 ~ 120 cc / 100g, TINT value 110 ~ 130 to improve the wear resistance, hysteresis loss (hysteresis loss ) Can be reduced (60 ° C. tanδ).

When the carbon black is preferably used 60 to 80 parts by weight, when the content is less than 60 parts by weight, the wear performance is reduced, and when more than 80 parts by weight, there is a problem that the workability is reduced.

In the present invention, when using 1 to 10 parts by weight of an environmentally friendly softener, if less than 1 part by weight has a problem of reducing workability and wet braking performance, there is a problem that rolling resistance is increased if more than 10 parts by weight.

Oil-B is an environmentally friendly oil containing 3% by weight or less of PAH, kinematic viscosity of 95 (210 ° F. SUS), 20% by weight of aromatic components, 32% of naphthenic components and 48% by weight of paraffinic components.

In addition, in the present invention, the wear and braking performance deterioration phenomena due to the use of oil having a low glass transition temperature is applied to synthetic rubber, softener content control, and appropriate vulcanization system, that is, sulfur treated with sulfur, preferably 1% naph. 2 parts by weight of sulfur treated with ten oil and 1.1 parts by weight of accelerator may be added to the rubber composition to improve wear resistance, braking performance and low fuel consumption performance.

The rubber composition according to the present invention uses neodymium butadiene rubber having a sheath content of 98% or more, which is advantageous for abrasion performance, and uses an oil of less than 3% by weight of PAH as an eco-friendly softener for flexibility and processability, as well as braking performance and low fuel consumption. The effect is improved.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited by the examples.

 [Comparative Example]

As shown in Table 1 below, 80 parts by weight of styrene butadiene 1 (SBR 1) rubber and 20 parts by weight of Ni-BR using nickel catalyst as the butadiene rubber are typically used as an additive of a rubber composition. ~ 13 m ² / g, DBP oil absorption 110 ~ 120, 70 ~ 80 parts by weight of carbon black with TINT value 110 ~ 130, 3.5 parts by weight galvanized, 1.5 parts by weight stearic acid, 2 parts by weight sulfur treated with oil, accelerator 1.1 4 parts by weight of a polycyclic aromatic oil having a content of at least 3% by weight and a PAH content of 90% (210 ° F. SUS), 40% by weight of an aromatic component, 30% by weight of a naphthenic component and 25% by weight of a paraffinic component. A rubber composition was prepared by blending in a negative blending ratio and vulcanized at 160 ° C. to prepare a rubber specimen.

Example 1

80 parts by weight of styrene butadiene 2 (SBR 2) rubber has a PAH content of 3% by weight or less, a kinematic viscosity of 95 (210 ° F. SUS), an aromatic component of 20% by weight, a naphthenic component of 32% and a paraffinic component A specimen was prepared in the same manner as in Comparative Example except that 4 parts by weight of 48% by weight of Low PAH Oil was used.

Example 2

As the butadiene rubber, carbon black with 20 parts by weight of Nd-BR using neodymium catalyst, nitrogen adsorption specific surface area is 135 ~ 145 m ² / g, DBP oil absorption 125 ~ 135 cc / 100g, TINT value 120 ~ 140 A specimen was prepared in the same manner as in Example 1 except for using 70 to 80 parts by weight.

Example 3

83 parts by weight of styrene butadiene 2 (SBR 2) rubber, 17 parts by weight of Nd-BR using neodymium catalyst as the butadiene rubber, 3 parts by weight of Low PAH Oil was the same as in Example 1 Was prepared.

Table 1. Rubber Compositions of Comparative Examples and Examples

Item Comparative example Example 1 Example 2 Example 3 SBR 1 80 - - - SBR 2 80 80 83 Ni-BR ¹ 20 20 - - Nd-BR ² - - 20 17 Carbon Black A ³ 75 75 75 Carbon Black B ⁴ - - 70 - Oil-A ⁵ 4 - - - Oil-B ⁶ - 4 4 3 Zinc oxide 3.5 3.5 3.5 3.5 Stearic acid 1.5 1.5 1.5 1.5 brimstone 2 2 2 2 accelerant 1.1 1.1 1.1 1.1 Hardness 64 63 64 64 100% Mod. 23 25 22 23 Abrasion Resistance ⁷ 100 97 105 102 Braking Performance ⁸ 100 96 90 102 Low fuel consumption ⁸ 100 104 115 110

Table 2. SBR Characteristics Comparison

SBR type Styrene content (%) Molecular Weight Tg (℃) Extended Oil Type SBR 1 20-25 760,000 -48 to -51 Aromatic oil SBR 2 22-27 890,000 -51 to -55 TDAE

1. Ni-BR ¹ : Sheath content 96%, glass transition temperature is -103 ~ -106 ℃, molecular weight distribution is 5.0 ~ 6.0.

2. Nd-BR ² : Sheath content over 98%, glass transition temperature is -105 ~ -110 ℃, molecular weight distribution is 2.1 ~ 3.1.

3. Carbon black A ³ : Nitrogen adsorption specific surface area 110 ~ 130 m ² / g, DBP oil absorption 110 ~ 120 cc / 100g, TINT value 110 ~ 130.

4. Carbon black B ⁴ : Nitrogen adsorption specific surface area is 135 ~ 145 m ² / g, DBP oil absorption 125 ~ 135 cc / 100g, TINT value 120 ~ 140.

5. Oil-A ⁵ : PAH content of 3% by weight or more, kinematic viscosity 90 (210 ℉ SUS), 40% by weight of aromatic components, 35% by weight naphthenic components and 25% by weight paraffinic components.

6. Oil-B ⁶ : PAH content is less than 3% by weight, kinematic viscosity 95 (210 ℉ SUS), containing 20% by weight of aromatic components, 32% by weight naphthenic components and 48% by weight paraffinic components.

7. Abrasion resistance: Tested with a rambon abrasion tester, the larger the index, the better the wear resistance.

8. Braking performance and low fuel consumption: 0.5% strain, 10 Hz, Temp. With RHEOMETRICS DYNAMIC SPECTROMETER. Sweep to measure 0 ° C. tanδ and 60 ° C. tanδ. The larger the index, the better the performance.

Oil-A (Aromatic oil) and Oil-B (TDAE oil) have different glass transition temperatures (Tg) due to the difference in composition and thus have different performances in the rubber composition.

Oil-B has a lower glass transition temperature than Oil-A, which is superior to Oil-A in terms of fuel efficiency, but disadvantages in terms of braking performance.

This is shown well in the comparative test results of Table 1 and the performance test results of Example 1. Butadiene rubber (Nd-BR) using a neodymium catalyst was used in the present invention to supplement the wear resistance while utilizing the advantages of Oil-B, and the wear resistance was improved as in Examples 2 and 3.

In addition, it was possible to confirm the carbon black particle size maximizing the performance of the rubber composition through Examples 2, 3, synthetic rubber and oil content control was able to achieve a value equal to or greater than the comparative example without deterioration.

As shown in the above results, carbon black A was added to butadiene rubber (Nd-BR) using a neodymium catalyst, and 2 parts by weight of sulfur and 1.1 parts by weight of accelerator were added. A tire tread rubber composition capable of simultaneously improving wear resistance, braking performance, and fuel efficiency with tensile properties could be obtained.

Claims (5)

70 to 90 parts by weight of raw material rubber consisting of 70 to 90 parts by weight of the emulsion polymerization styrene butadiene rubber and 10 to 30 parts by weight of neodymium butadiene rubber, including 60 to 80 parts by weight of carbon black and 1 to 10 parts by weight of an environment-friendly softener, The eco-friendly softener has a total content of polycyclic aromatic hydrocarbon (PAH) of 3 wt% or less, a kinematic viscosity of 95 (210 ° F. SUS), an aromatic component of 15-25 wt%, a naphthenic component 27-37%, and a paraffinic component 38 Eco-friendly tire tread rubber composition, characterized in that 58% by weight. The eco-friendly tire tread rubber composition according to claim 1, wherein the emulsion polymerization styrene butadiene rubber has a styrene content of 22 to 27%, a molecular weight of 890,000 or more, and a glass transition temperature of -51 to -55 ° C. The environmentally friendly tire tread rubber composition according to claim 1, wherein the neodymium butadiene rubber has a glass transition temperature of -105 to -110 ° C, a cis content of 98% or more, and a molecular weight distribution of 2.1 to 3.1. The environmentally-friendly tire tread rubber composition according to claim 1, wherein the carbon black has a nitrogen adsorption specific surface area of 110 to 130 m ² / g, a DBP oil absorption of 110 to 120 cc / 100 g, and a TINT value of 110 to 130. delete