KR100919881B1 - Rubber composition for tire tread - Google Patents

Abstract

The present invention relates to a tire tread rubber composition, and is a tire tread rubber composition comprising 3 to 20 parts by weight of a polybutadiene urethane oligomer represented by the following formula (1) based on 100 parts by weight of raw rubber.

Formula 1

In the above, x and y are 1 to 3, z is 3 to 8, R is hydrogen or an alkyl group of C ₁ to C ₅ , R ₁ is hydrogen or an alkyl group of C ₁ to C ₃ .

The rubber composition according to the present invention can provide environment-friendly compounded rubber and at the same time improve the overall properties such as wear and low fuel consumption properties.

Description

Rubber composition for tire tread

The present invention relates to a tire tread rubber composition, and more particularly, by using polybutadiene urethane oligomers in place of conventional aromatic oils having PAH content and harmful substances above the reference value, to provide an eco-friendly blended rubber and at the same time wear and low fuel consumption characteristics and It is a rubber composition which can improve the same general property.

Recently, as environmental awareness increases, environmental problems such as loss of life, noise, depletion of raw materials, and air pollution caused by automobiles, which are becoming necessities, are emerging.

With this in mind, the European Union will stipulate restrictions on hazardous substances in automobile scrapping. The substances that can occur in tires are contained in four heavy metals that may be contained in metal salts and aromatic oils used as processed oils. Polycyclic Aromatic Hydrocarbons (PAHs) are available, and the tire industry is researching and developing new raw materials to cope with these regulations.

In particular, the problem of heavy metals can be solved by using more pure raw materials that meet the regulatory standards. However, when processing oils with low PAH content are applied, it is difficult to design the compound rubber because it causes the sacrifice of the physical properties of the compound rubber.

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 the wear resistance, braking performance and low fuel consumption of a tire while using an eco-friendly softener polybutadiene urethane oligomer.

In order to achieve the above object, an object of the present invention is to provide a tire tread rubber composition comprising 3 to 20 parts by weight of a polybutadiene urethane oligomer represented by the following formula (1) based on 100 parts by weight of raw rubber.

Formula 1

Where x and y are 1 to 3, z is 3 to 8, R is hydrogen or C ₁ To C _{5 is} an alkyl group, R ₁ is hydrogen or C ₁ To C _{3 is} an alkyl group.

The polybutadiene urethane oligomer preferably uses a weight average molecular weight of 2,000 ~ 20,000.

In the present invention, a polybutadiene urethane which is vulcanizable by sulfur such as rubber without containing an environmentally harmful substance such as PAH is used as a rubber softener.

The polybutadiene urethane includes 3 to 20 parts by weight based on 100 parts by weight of the raw material rubber. If the content is less than 3 parts by weight based on 100 parts by weight of the raw material rubber, the processability imparting property is insignificant. There may be a problem of deteriorating mechanical and other physical properties.

The raw material rubber of the present invention is a diene polymer used in a general tire tread rubber composition, and is not particularly limited.

In the present invention, carbon black or silica is used as the reinforcing agent, and the content thereof is usually about 20 to 90 parts by weight based on 100 parts by weight of the raw material rubber.

The tire tread composition of the present invention uses polybutadiene urethane when formulating a rubber composition, and may include oil, a vulcanization accelerator, an anti-aging agent, and the like as a sulfur vulcanizing agent, zinc oxide as a vulcanizing agent, stearic acid, and a softener.

The rubber composition according to the present invention can provide environment-friendly compounded rubber and at the same time improve the overall properties such as wear and low fuel consumption properties.

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

Example  And Comparative example

 The rubber composition was prepared by blending the compounding agent in a half-barrier mixer as shown in Table 1, and the rubber samples using natural rubber among the unvulcanized physical properties and the obtained rubber samples were vulcanized at 150 ° C. and rubber samples using styrene-butadiene rubber. Was vulcanized at 160 ° C. for physical properties.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Comparative Example 3 Comparative Example 4 Example 3 Example 4 NR 100 100 100 100 SBR 100 100 100 100 Aromatic oils 10 20 10 20 Polybutadiene Urethane Oligomer 10 20 10 20 Carbon black 50 50 50 50 50 50 50 50 Zinc oxide 5 5 5 5 3 3 3 3 Stearic acid 3 3 3 3 One One One One Antioxidant (6C) 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 TBBS 0.8 0.8 0.8 0.8 1.0 1.0 1.0 1.0 sulfur 2.2 2.2 2.4 2.6 1.8 1.8 2.0 2.2 Note) -NR: Natural rubber, RSS # 3 Grade-SBR: SBR (SBR1500 Grade)-Carbon black with 25% styrene content: HAF N330-Polybutadiene urethane oligomer: Weight average molecular weight 2,000 ~ 20,000, x and y are 1 To 3, z is 3 to 8, R is-hydrogen or an alkyl group of C1 to C5, R1 is hydrogen or an alkyl group of C1 to C3-anti-aging agent (6C): N-1,3-dimethylbutyl-N -Phenyl-p-phenylenediamine-TBBS: N-isobutyl-2-benzothiazyl sulfenamide

In Table 2, the physical properties of the rubber specimens obtained according to Comparative Examples and Examples of Table 1 are the wear index ratios of the rambon, and the loss amount of the worn rubber was rotated at a sliding ratio of 25% and a load of 1.5 kg at room temperature. The higher the value, the better the wear performance.

* Wear Index = (wear amount of comparative example / wear amount of example) × 100

0 ° C Tan δ is a measure of wet road braking performance, which means that the higher the value, the better. 60 ° C Tan δ is a measure of rotational resistance at 60 ° C.

Physical property test result Comparative Example 1 Comparative Example 2 Example 1 Example 2 Comparative Example 3 Comparative Example 4 Example 3 Example 4 300% Modulus 100 80 104 82 96 75 92 71 Wear index 100 105 110 125 100 108 115 130 0 ℃ Tan δ 0.123 0.132 0.125 0.129 0.172 0.178 0.176 0.179 60 ℃ Tan δ 0.085 0.092 0.078 0.075 0.131 0.136 0.121 0.119

According to Table 2, the wear index and 60 ℃ Tan δ of the embodiment using the polybutadiene urethane oligomer compared to the comparative example showed excellent overall characteristics compared to the comparative example.

By using the polybutadiene urethane oligomer according to the present invention, it was confirmed that the rubber tread composition is useful because it can improve the abrasion and low fuel consumption characteristics of the rubber and at the same time can be environmentally friendly.

Claims (3)

It contains 3 to 20 parts by weight of a polybutadiene urethane oligomer represented by the following formula (1) based on 100 parts by weight of the raw material rubber, The polybutadiene urethane oligomer is a tire tread rubber composition, characterized in that the weight average molecular weight of 2,000 ~ 20,000. Formula 1 X and y are 1 to 3, z is 3 to 8, R is hydrogen or an alkyl group of C ₁ to C ₅ , R ₁ is hydrogen or an alkyl group of C ₁ to C ₃ . delete The tire tread composition according to claim 1, further comprising 20 to 70 parts by weight of carbon black, 1 to 10 parts by weight of vulcanizing agent and 0.5 to 3 parts by weight of vulcanizing agent, based on 100 parts by weight of the raw material rubber.