The characteristics of green tires are not only reflected in green and safe end products, such as low rolling resistance, low noise, anti wet sliding, and high grip performance, but also in the production process of tires, such as the use of green raw materials, green research and development ideas, green process configuration, resource conservation, and recycling. Among them, the greening of rubber additives has to be mentioned.

 

The media has learned that traditional tire production processes require the use of rubber additives that are harmful to human health and the environment, inevitably causing adverse effects. At the same time, harmful additives can emit in the environment and cause pollution with the use and wear of tires. The manufacturing of green tires requires the use of environmentally friendly additives, which are controlled from the source to meet the requirements of green tires. Through nearly 10 years of efforts, China's rubber additives have basically achieved environmentally friendly and green substitution, with production scale accounting for about half of the global total.

 

It is understood that there are six main categories of additives used in the rubber industry: vulcanization system additives, also known as accelerators; Protective system additives, also known as antioxidants; Operating system additives, including plasticizers, softeners, etc; Reinforcement filling system additives, such as carbon black and white carbon black; Adhesive system additives, such as triazine adhesives; Other additives such as colorants. In 2014, the total production of six types of rubber additives in China was about 5.8 million tons, with carbon black and white carbon black reinforcing fillers accounting for about 80%, and accelerators and antioxidants accounting for about 16% of the total. These are the three rubber additives with the highest production and usage.

 

In the 1990s, Michelin Company introduced high-performance green tires using highly dispersed white carbon black, and green tires gradually became accepted by the public due to their comfortable, safe, environmentally friendly, and energy-saving characteristics.

 

In recent years, the global production of green tires using silica has maintained an annual growth rate of 10% to 20%, and an increasing number of original tire indicators have begun to specify the addition of silica. With the increasing demand for environmental protection, energy conservation, and comfort in China, the application proportion of white carbon black in tires is also increasing.

 

At present, white carbon black exhibits excellent performance in reducing rolling resistance and improving grip performance, and is widely used in snow tires, anti slip tires, and green tires. Data shows that in 2012, the amount of white carbon black added to domestic tires was only 180000 tons, but by the end of this year, it is expected that the use of white carbon black in domestic tires is expected to reach around 600000 tons.

 

The progress in accelerators and antioxidants is also quite rapid. Ten years ago, NOBS (N-oxidized diethylene-2-benzothiazolesulfonamide) was still the main type of promoter, and this auxiliary agent was considered harmful to human health abroad. After nearly a decade of development, the safe and green accelerator mainly composed of accelerator NS (N-tert butyl-2-benzothiazolesulfonamide) has basically replaced the accelerator NOBS.

 

Zhang Fang, Assistant Dean of the Petroleum and Chemical Industry Planning Institute, pointed out that the development direction of high-end rubber additives in the future is mainly reflected in three aspects.

 

One is to optimize and adjust the product structure of reinforcing fillers to meet the needs of green tire development. Replacing carbon black with white carbon black can reduce the rolling resistance of tires. In the future, the proportion of white carbon black in reinforcement fillers will continue to increase, and the adhesive additives of silane coupling agents that are matched with it will also develop rapidly.

 

The second is to promote the green and clean production process of rubber additives. The most common rubber additives are accelerators and antioxidants, while the largest amount of antioxidant used in China is antioxidant 4020. It is understood that the traditional production process of 4020 produces a large amount of "three wastes". Currently, the production process that is environmentally friendly and cost-effective is based on nitrobenzene as the starting material, and RT Beisi (N-phenylphenylphenylenediamine) is used to produce antioxidant 4020. In recent years, multiple sets of devices have been put into operation for the production of antioxidant 4020 using this process route. In the future, efforts should be made to replace traditional process routes such as the formylaniline method.

 

The third is to further promote the environmentally friendly substitution of rubber additives. The recent focus is on the environmentally friendly substitution of operating system additives, such as using cycloalkane filling oil to replace aromatic oil with high polyaromatic content, and using plasticizer DBD (2,2-diphenylformamide diphenyl disulfide) to replace plasticizer B (pentachlorophenol).

 

With the deepening development of the concept of green tires, some domestic enterprises and research institutes have begun to conduct research on green tire technology. In addition to additives, the entire industrial chain of domestic tire manufacturing, materials, equipment, machinery, and other industries is also developing synchronously, and all foundations are gradually being cultivated. These have laid a good foundation for the development of green tires in China, and China will be closer to achieving the goal of becoming a strong country in the world tire industry.