The Independent Innovation Path Of Chinese Silicone Sealant
Silicone building sealant (commonly known as silicone glue) is an important part of silicone polymer materials. It can cure into elastic rubber at room temperature without heating, light irradiation or other external conditions, making it extremely easy to use. Besides the excellent properties of general silicone materials such as high and low temperature resistance, weathering aging resistance and high electrical insulation, it also features good adhesion to various substrates and strong displacement resistance. It has become an essential sealing material for modern architectural decoration.
Developed countries in Europe and the United States launched two-component silicone sealants for the construction industry in the early 1950s. High-performance one-component silicone building sealants were commercially available in the early 1960s. In the 1970s, silicone structural sealant was first applied to the structural bonding and assembly of fully hidden frame glass curtain walls, and has been in practical use for more than 40 years with excellent performance.
Along with the development of silicone glue, several other high-performance sealants were developed worldwide, mainly including polysulfide, polyurethane, acrylic and butyl types. In terms of overall comprehensive performance, silicone sealant ranks the best, making it the only structural and weatherproof sealing material adopted for glass curtain walls.
In terms of consumption volume, silicone sealant accounts for only about one-third of the total sealant market overseas due to its higher price. In recent years, ordinary organic materials have been used to modify silicone polymers to develop low-cost sealants with similar performance.
In the 1990s, Japan developed silane-terminated polyether polymer materials. Its curing mechanism draws on the crosslinking reaction of dealcoholized silicone glue. The formed elastomer is paintable, causes little contamination to porous materials such as stone, and has good dust resistance. It has been widely used in prefabricated buildings and formed a distinctive MS polymer system.
The domestic market situation is quite different. Except for acrylic sealants which are low-priced and widely used, the prices of polysulfide and silicone sealants are close, while polyurethane is even more expensive than silicone. As a result, silicone sealant occupies nearly 80% of China’s market share. This pattern may change soon due to the sharp rise in silicone raw material prices.
After decades of development, the foreign silicone glue industry has formed a complete supporting system for raw materials and special production equipment, realizing large-scale continuous production. Major manufacturers are concentrated in global silicone giants such as Dow, Momentive, Wacker and Shin-Etsu, with a global total annual output exceeding 900,000 tons.
China’s research and development of silicone glue started in the 1960s. In 1965, silicone R&D forces from Shenyang Research Institute of Chemical Industry and Beijing Research Institute of Chemical Industry were integrated into the newly built Chenguang Research Institute of Chemical Industry, which was relocated to Fushun, Sichuan in the mid-to-late 1960s. Since then, Sichuan has gradually become China’s silicone industry hub.
Chenguang Research Institute provided indispensable high-performance silicone materials for China’s missiles, satellites and cutting-edge weapons, laying a solid foundation for today’s domestic silicone industry. Sichuan is also the birthplace of China’s silicone building sealant. In the 1970s, Chenguang Research Institute developed high-performance silicone adhesives for solar panels on China’s artificial satellites, which became the prototype of modern silicone structural sealant for construction.
In the 1980s, the institute undertook the national Seventh Five-Year Key Scientific and Technological Research Project to develop silicone building sealants, and transferred the technology to three enterprises in Sichuan, Jiangsu and Guangdong. Starting from the 1990s, 200L and 500L vacuum planetary mixing machines were specially designed and manufactured for the industrial production of silicone glue. Without such dedicated equipment, domestic manufacturers would have to import alternatives costing 5–10 times more, losing cost and price competitiveness. All these efforts laid the necessary foundation for large-scale industrial production of silicone glue in China.
While providing technology and equipment for domestic manufacturers, Sichuan has also cultivated a large number of professional talents. These professionals have contributed to coastal enterprises, enabling mass production, sales and export of Chinese silicone products, and making China an important production base for silicone glue worldwide.
From the late 1980s to the early 1990s, many domestic enterprises carried out pilot industrial development of silicone glue, including Guangzhou Baiyun Adhesive Factory, Nanhai Jiamei Fine Chemicals, Zhengzhou Zhongyuan Applied Technology Research Institute and Jiangmen Pesticide Factory.
In the 1990s, the industrialization and market expansion of silicone glue accelerated significantly. Under the leadership of Wang Yuelin, Nanhai Jiamei completed China’s first 6kt/a acidic silicone glue production line in 1993, becoming the first enterprise to realize large-scale industrial production of silicone glue in China.
In 1992, Guangzhou Baiyun introduced pilot-scale silicone glue technology from Chenguang Research Institute for industrialization. Initially plagued by unstable product quality, the enterprise faced severe operational difficulties and was on the verge of bankruptcy. In 1995, Guangzhou Baiyun appointed Wang Yuelin as technical director. In a short time, he solved the problem of stable mass production of dealcoholized room-temperature curing silicone glue and realized full product serialization.
In particular, he led the successful development of silicone structural sealant for construction, breaking the technological monopoly of the United States, Germany and other countries in this field. He made outstanding contributions to the development of China’s silicone sealant and glass curtain wall industries, and was awarded the 1999 Guangzhou Science and Technology Outstanding Contribution Golden Tripod Award. Guangzhou Baiyun soon grew into a leading enterprise in China’s silicone glue industry.
Meanwhile, outstanding enterprises including Zhengzhou Zhongyuan, Hangzhou Zhijiang Silicone and Zhejiang Lingzhi Fine Chemicals completed industrialization construction one after another, driving vigorous development of domestic silicone sealant market.
After nearly 50 years of persistent efforts by generations of practitioners, especially since the 1990s, the successful domestic industrialization and large-scale civilian application of silicone glue have boosted the rapid growth of China’s silicone raw material industry, which in turn fueled explosive expansion of the silicone sealant sector.
In just over 20 years, China’s silicone glue industry has expanded from an annual output of ten thousand tons to over 600,000 tons, with more than 200 manufacturers and tens of thousands of employees. Manufacturing equipment, product quality supervision and standard systems have been fully established and reached world advanced levels within two decades.
China’s silicone market has evolved from being completely dominated by foreign brands to accounting for more than half of global output today. Domestic products hold over 90% of the home market and sell well worldwide. The development of China’s silicone sealant industry embodies the unremitting efforts of generations of practitioners, stands as another remarkable achievement witnessing China’s economic miracle, and represents a successful example of China’s new material industry building international competitiveness through independent innovation and development of national industry.