Under the joint research of BLSH Petrochemical Company, Sichuan University, Beijing University of Chemical Technology, Hunan Baili Engineering Technology Co., Ltd., etc., it took 15 years for China to finally develop a set of industrialized SEBS technology with independent intellectual property rights, making green SEBS an alternative Materials have enhanced the core competitiveness of China's medical, consumer electronics, daily necessities and other industries closely related to national economy and people's livelihood. The new generation of high-performance styrenic thermoplastic elastomer complete technology project has also won the 2014 National Science and Technology Progress Award.
SEBS has the characteristics of aging resistance, safety, non-toxicity, and environmental protection. It is known as "rubber gold" in the industry. It is mainly used in pharmaceutical packaging, medical infusion devices, long-span lubricants, food packaging, wires and cables, sealing materials, and plastics. Properties, high-grade asphalt modification and elastic materials in contact with the human body. According to Liang Hongwen, the first finisher of the project and deputy director of the Rubber and Plastic Center of the BLSH Synthetic Rubber Division, before the successful localization of SEBS, its technology was monopolized by two companies in the United States and Japan. "We visited the United States and hoped that the other party would transfer technology, but it was rejected." Liang Hongwen recalled. At that time, the company only transferred low-end SBS production technology to Brazil, and the software fee alone was as high as $ 20 million. Since then, several units in China have conducted small-scale research on SEBS. Due to the failure to achieve breakthroughs in the design and control of polymer microstructures and hydrogenation technologies, they have not been able to achieve industrialization, resulting in SEBS import prices as high as 50,000 to 80,000 yuan / ton. Directly affect the competitiveness of China's downstream industries.
In 1996, the project team started from scratch and began research on the synthesis technology of SEBS precursors and the catalytic hydrogenation technology of the Mao series. In 1998, the project team completed the SEBS pilot test and passed the identification of Sinopec technology. In 2003, the SEBS pilot technology development was completed. "As soon as the news of our pilot test came out, a Japanese company actively asked us to seek cooperation and jointly promote industrialization, but we did not agree, and we wanted to complete this feat with our own strength." Liang Hongwen said. In March 2006, the first set of 10,000-ton-per-year SEBS industrialization equipment with full independent intellectual property rights in China was put into operation in the Baling Petrochemical Synthetic Rubber Business Unit, and industrial tests of a total of 11 brands of linear and star series have been completed. The product performance is stable and has been recognized by users, filling the gap in domestic SEBS production; in 2009 and 2012, the total annual production capacity of Baling Petrochemical SEBS expanded to 20,000 tons and 40,000 tons, respectively.
According to Liang Hongwen, the project has achieved four major innovations.
The first is to solve the problem that the traditional SBS polybutadiene segment has a low 1,2-structure content, uneven distribution, and cannot be used as a SEBS precursor. A systematic characterization method for the SEBS microstructure was established, and a SEBS precursor microstructure model was established. Invented SEBS series precursor structure design method to meet different performance requirements.
The second is to study the effect of the complexation state of the alkyl lithium initiator and the structure modifier on the polymerization rate and microstructure of the monomer. Invented a synthetic control method for the SEBS series precursor structure, and realized a wide range of precursor molecular structure design. And fine and stable control, developed a total of 11 brands of star and linear series.
The third is to reveal the metallocene catalytic hydrogenation mechanism, invented a new metallocene hydrogenation process, and developed a new technology for the efficient removal of trace metal ions in high polymers. The amount of catalyst used is only 10% of the nickel-based hydrogenation process ~ 15%, energy consumption and material consumption are significantly reduced, environmental protection, product quality meets medical and health standards.
The fourth is to solve the problems of mass and heat transfer of high-viscosity materials in polymerization kettles and gas-liquid mass and heat transfer of high-viscosity materials in hydrogenation kettles. The world's largest 80 cubic meter precursor SEBS polymerization kettle and hydrogenation kettle were developed to ensure It has high production efficiency, low cost and stable product quality. On this basis, a complete set of 10,000-tonne-series hydrogenated SEBS technology was formed.
During the project implementation period, the project team published 38 papers and obtained 14 Chinese invention patents, forming 12 Sinopec proprietary technologies.