China’s SSBR Sector Needs Upgrades

By Cui Xiaoming, Beijing Chemical Research Institute

Solution-polymerized styrene-butadiene rubber (SSBR) has extensive applications in the shoe and tire industries – especially high-performance tires such as “green” tires, anti-skid tires and super light-weight tires, because of its wear resistance, cold resistance, low heat generation, low shrinkage, good color and luster, low ash, high purity and high vulcanization speed. It also has low rolling resistance, excellent wet-skid resistance and abrasion resistance. At present, SSBR for domestic production of high performance tires is mainly imported because the domestically produced SSBR products cannot meet the quality and performance requirements.

High-performance tires promote global growth of demand for SSBR

With the startup of new or expanded units in Mainland China, Singapore, South Korea and Germany, the global capacity to make SSBR has increased steadily. At the end of 2013, there were over 20 SSBR units located in more than a dozen countries and regions such as the United States, Japan, France, Germany and China, with a total capacity of 1.886 million t/a. In Asia, North America and Western Europe alone, the combined SSBR capacity was 1.759 million t/a, around 93.27% of the total. The United States is the largest SSBR producer, with 464 000 t/a capacity, around 25% of the total. China is the second largest, with a capacity of 367 000 t/a, around 20%. Japan is third, with a capacity of 204 000 t/a, around 11%.
The rapid growth of global demand for high-performance tires has promoted constant growth of demand for SSBR, so some enterprises like Asahi-Kasei of Japan, LANXESS, and Sibur Holding of Russia plan to construct or expand SSBR units. If these units are put into production on schedule, it is expected that by 2016, the world’s SSBR capacity will reach 2.5 million t/a.
In 2013, around 250 000 tons of SSBR was consumed in the world. Eighty percent of it was used in tires, and the rest was used in plastic modification and shoe making.

Demand growth in China

At the end of 2013, the domestic consumption of SSBR was only around 125 000 tons, mostly used in making shoes and tires. As the SSBR produced in China contains less vinyl group, its wet-skid resistance, rolling resistance and quality stability are surpassed considerably by imported products. Domestic SSBR is therefore used only in bias tires. The SSBR for radial tires is mainly imported. For example, the high-grade tires produced by South China Rubber & Tire Co., Ltd all incorporate imported SSBR. Nanjing Kumho Tire Co., Ltd also uses imported SSBR in tires for high-grade domestic sedans. The imported SSBR mainly comes from LANXESS, Asahi-Kasei of Japan, Firestone of the United States, Zeon Corporation of Japan or Kumho of Korea.

Table 1   China’s Major SSBR Producers in 2013

Producer    Capacity
(kt/a)    Technology source    Startup time    Remarks
Sinopec Beijing Yanhua Petrochemical Co., Ltd    30    Its own technology    1996    Producing byproduct SBS
Sinopec Maoming Petrochemical Co., Ltd    30    Technology from Fina    1997    Producing byproduct SBS
Sinopec Gaoqiao Petrochemical Co., Ltd    67    Technology from Asahi-Kasei of Japan    2006    Producing byproduct LCBR
PetroChina Dushanzi Petrochemical Co., Ltd    100    Technology from Polimeri Europa of Italy    2009    Producing byproduct LCBR
Shandong Huamao New Materials Co., Ltd    100    -    2011    -
Shandong Jusage Technology Co., Ltd    40    -    2012    Producing byproduct SBS
Total    367    -    -    -


The popularity of radial tires, especially the development of energy-saving radial tires or other new types, has put higher requirements on the performance of rubber for tires. It must have high strength and good wet-skid resistance, as well as low rolling resistance. (10% - 20% of vehicle fuel is used to overcome the rolling resistance of tires.) Emulsification-polymerized styrene-butadiene rubber (ESBR) has good wet-skid resistance but high rolling resistance. Natural rubber and cis-1,4-polybutadiene rubber have low rolling resistance but poor wet-skid resistance. Only SSBR has both good wet-skid resistance and low rolling resistance. China’s radial tire sector has good development prospects, so its demand for SSBR will increase constantly. It is expected that China’s demand for SSBR will reach 230 000 tons by 2018.
At present, China’s capacity to make SSBR has reached 367 000 t/a; however, the operating rate of SSBR units is still not high, and the application field is narrow. Of course there is steady demand in the shoe making sector, but among tire makers, very few are interested, and overall, the growth of consumption is far slower than in developed countries. There are many reasons for this. For example, Chinese automakers have no clear requirements for tires’ energy-saving, environment-friendliness or driving-safety; the price of high-performance tires is higher; domestic purchasing power is poorer; and most domestic tire factories do not have the conditions for using the SSBR formula and related equipment.
The production cost of SSBR is higher than that of ESBR, and the interchangeability among the products from different SSBR producers is poorer. ESBR products of the same grade can generally be substituted for each other. At present, domestic tire enterprises (excluding joint venture enterprises) typically have not tried to use SSBR in tire production. Advanced firms have begun to experiment. The lower prices of ESBR and natural rubber are an impediment. China produces only a single variety of SSBR, and its properties do not fully meet the needs of different users. In addition, due to inadequate product dissemination, China’s SSBR sector still has a long way to go.

China’s SSBR sector needs to be improved

In view of the present status of the domestic SSBR sector, as well as the trends of international development, we offer a number of suggestions to enhance the competitiveness of China’s SSBR sector:
China should improve the production technology of the domestic SSBR sector overall. Continuous polymerization production technology should be actively developed and promoted. Continuous polymerization is an important way to adapt large-scale production of SSBR, increase production efficiency and reduce production costs.
China should speed up the development of SSBR with low rolling resistance, high wet-skid resistance and good wear resistance. Players should accelerate the expansion of SSBR varieties, adjust the product portfolio and learn to meet the needs of different users.
China should exercise caution in authorizing/funding construction of more SSBR capacity. In developed countries, most SSBR is used only for the production of high-performance tires, but in China, the speed of vehicles is mostly below 180 kilometers per hour, ESBR has been able to meet the requirements, and the demand for high-performance tires is smaller. Hence, the demand for SSBR in the domestic market is not big. In addition, the processing performance of SSBR is inferior to that of ESBR except the application in tread stock. In other application fields – tire carcass ply compounds and buffer layers, as well as rubber hoses and adhesive tapes – the comprehensive performance of SSBR is still inferior to that of ESBR. In addition, the production cost of SSBR is higher than that of ESBR, so the domestic production of styrene-butadiene rubber (SBR) will still be dominated by the emulsion polymerization method for a period of time.  
China should conduct a comprehensive performance evaluation (e.g., analysis and detection of processing characteristics) for the existing domestic SSBR products, and offer technical services for the direct consumers to speed up the evolution of SSBR production, development and marketing, and to promote the development of China’s SSBR sector, as well as its related sectors.