Liang Tao, Research Institute of PetroChina Co., Ltd.
Emulsion polymerized styrene butadiene rubber (ESBR) can be widely used, together with natural rubber (NR) and a variety of synthetic rubber (SR), in the production of tires, tire-related products and rubber products such as shoes, hoses, tapes, etc.
Despite dramatic changes in the synthetic rubber market and the real demand, ESBR still has the largest capacity, and the market will keep up with the growing tyre industry by the development of new brands, new formulas and processes. With its cost edge, the ESBR market will see more robust demand, while having higher export competitiveness in the future. Its consumption will be the biggest and its operability will be strong.
Developing butadiene in China is imperative
In response to the rapid development of the ethylene industry, a number of ethylene plantsfrom private producers such as Hengli and Zhejiang Petrochemical have been on stream, and hence the supply of C4 and C5 continues to increase. It is estimated that the supply of C4 will exceed 6 million tons and that of C5 will exceed 4 million tons by 2025. The domestic C4 and C5 markets will eventually turn into oversupply, weighing down on the prices of butadiene and squeezing the margin room of synthetic rubber producers in the long term.
Driven by the rapid ethylene capacity expansion, China's butadiene market supply is becoming loose. It is expected that there will be a new peak of ethylene plants start-up during the 14th Five-Year Plan period (from 2021 to 2025), and the capacity of the byproduct C4 extraction butanediene plants will also have a whopping rise. As a result, the supply in butadiene market will keep increasing, while the demand from downstream synthetic rubber will slow down, narrowing the margin room of butadiene producers. Therefore, it is imperative for producers to develop new and quality butadiene rubber products.
Tire materials for new energy vehicle to be of highperformance and be green
With the development of domestic automobile industry, especially the rapid growth of electric vehicles and specific new energy vehicles, there are new requirements for tires. According to the data of China Passenger Car Association, the wholesaled new energy passenger vehicles in 2021 were 3.312 million, an increase of 181% year on year; the retailed new energy vehicles were 2.989 million, an increase of 169% year on year; the retail penetration rate of new energy passenger vehicles was 14.8%, much higher than the rate of 5.8% in 2020.
There is a big difference in the power structure between electric vehicles and internal combustion engine vehicles. The tires for traditional fuel vehicles cannot meet the special performance requirements of electric vehicle tires. Electric vehicles have requirements for higher load capacity of tires, and new energy vehicles have requirements for tires with low rolling resistance, low noise, high wear resistance and strong grip, challenging tire makers in terms of the structural design of tires and the selection of raw materials. Generally speaking, the average service life of tires for internal combustion engine vehicles is 5-6 years, while that of tires for new energy vehicles is reduced to 4-5 years. Therefore, it is necessary to develop new SBR modified materials so as to meet the needs of high-performance green tires.
In the process of transformation from internal combustion engine vehicles to new energy vehicles, all of the relevant industrial chains will be reshaped, which will not only change the global automobile brand ranking, but also change the competitive situation of the tire market. There will be new requirements for basic materials of tires.
ESBR capacity has increased sharply
During the 12th Five-Year Plan period and the 13th Five-Year Plan period, China's ESBR capacity increased sharply and a number of new grades also increased. At present, China's ESBR capacity is 1.515 million t/a, and PetroChina is dominant, with a total capacity of 490 000 t/a. Table 1 shows the main ESBR producers in China.
Promoting the high-end customized development mode during the 14th Five-Year Plan period
The capacity of synthetic rubber at home and abroad stabilized during the13th Five-Year Plan period, snapping the explosive growth during the 12th Five-Year Plan period, and producers attached more importance to the adjustment of product structure, which gave a push for the development of higher-quality ESBR. With the independent innovation of China's ESBR technologies toward new and modified grades, the market will meet application needs for new energy vehicles and the demand from the growing tire industry. The domestic producers will keep upgrading technologies and developing products so as to roll out new grades and technologies of ESBR. With the mergers and acquisitions, the industry is more concentrated, and leading producers will outperform in terms of varieties, grades and brands.
The development of China’s ESBR technologies is environment-friendly, systematic, serialized and customized. The main ESBR technologies will reach the advanced international level in the future, continuously making breakthroughs in high-performance technology, residual monomer removal technology, ternary copolymerization technology, low-cost technology, modification technology and new brand development.
Producers will continue to shore up the high-end customized development mode so as to make refined products and meet needs from the growing tire industry during the 14th Five-Year Plan period. In terms of advanced reservation technology, producers will focus on the development of polyurethane modified ESBR technology, the development of wear-resistant modified products, the preparation technology of liquid emulsion polymerized SBR, the preparation technology of grafted SBR modified copolymer, the liquid-phase mixing master rubber technology, and the preparation technology of high solid-content latex. With the continuous improvement, the emulsion polymerized SBR process can be carried out in big-sized plants and the automatic control technology has reached a high level. In recent years, there have been great progress in improving the monomer conversion rate of polymerization reaction, saving energy and reducing consumption, improving polymerization formula and production process, improving modifying technology, and adding a third monomer or filler to improve the performance of ESBR. Many grades have been used in the production of high-performance tires, and their performance is even better than SSBR. As the government has implemented stricter energy-saving policy, the requirements on quality and service of synthetic rubber products will be increasingly higher.Developing local technologies, establishing specific core technologies, promoting the structural adjustment of products, and producing more specialtygrades with high added value remain as the main direction of technological development in the industry. Green rubber is an inevitable trend for the synthetic rubber market.
To develop customized products for tire manufacturers and to meet needs of tire makers at home and abroad will be accompanied by an improvement in high-quality synthetic rubber during the 14th Five-Year Plan period. The development of customized products is supportive to the upgrading of ESBR product structure. The content of ESBR in the tread of car and engineering vehicle tires is as high as 80%. On the back of fierce competition in the tire market, customers have higher and higher requirements for the quality of ESBR products, such as safety-layer rubber, high-performance car tread rubber, cutting- and puncture-resistance engineering tread rubber, and ESBR for conveyor belts. The development of new products and new grades will be of market focus in the future so as to solve the problems such as signle product structure, evident homogenization, and difficulties in meeting personalized needs of high-end users.
