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In the third quarter of 2026, a significant industrialization progress emerged in China's organosilicon new material sector: a continuous production unit for high-vinyl low-volatility vinyl silicone oil with a designed annual capacity of 42,000 tons officially achieved full-load stable operation. The vinyl content of the product can be precisely adjusted in the range of 0.5%-10%, the total volatile content is stably controlled below 18ppm, and the vinyl content deviation of products from different batches is less than 0.6%. This achievement marks that China's vinyl silicone oil industry has completely broken the long-term monopoly of overseas manufacturers in the field of high value-added special grades, and completed the technical coverage from general-purpose products to the full range of high-end customized products. It provides fully supply-chain-independent key raw material support for core downstream industries such as photovoltaic encapsulation, high-end medical silicone rubber and special electronic potting.
Vinyl silicone oil is the core hub material connecting upstream basic monomers and downstream end products in the organosilicon industrial chain. The vinyl active groups carried on its molecular chain are the core reaction sites to realize the silicon-hydrogen addition reaction, which directly determines the crosslinking density, mechanical properties and long-term service stability of downstream addition-cured silicone rubber. Different from general-purpose products with ordinary low vinyl content, high-vinyl silicone oil with a vinyl content higher than 2% is the core raw material for preparing special products such as high-tear-strength silicone rubber, high-thermal-conductivity silicone gel and high-expansion foamed organosilicon. Its three core indicators, namely the uniformity of vinyl distribution, small molecule residual content and active group retention rate, directly affect the service life and safety performance of downstream end products. For a long time in the past, the domestic industry generally adopted the traditional batch anionic polymerization process to produce high-vinyl silicone oil, which not only had low production efficiency and poor batch stability, but also long faced the industry problems of vinyl group deactivation and local crosslinking gelation during polymerization. The produced products generally had problems such as uneven vinyl distribution and residual small molecule cyclic siloxanes (D3-D12) exceeding 300ppm, and could not meet the strict requirements of high-end downstream scenarios. Previously, nearly 90% of the market share of ultra-high-purity high-vinyl silicone oil used in domestic new energy, high-end medical and other fields has long been occupied by leading overseas enterprises. Not only was the procurement price 5-7 times that of general products, but the delivery cycle for special customized grades even exceeded 10 months. Some special specification products involving cutting-edge aerospace and semiconductor fields have long faced the risk of export control, which has seriously restricted the technological iteration speed of downstream industries.
The new continuous production process that has achieved full production this time has corely broken through three technical bottlenecks that have plagued the industry for decades. First, a controllable ring-opening polymerization system with directional embedding of vinyl monomers was pioneered. The technical team abandoned the idea of the traditional batch process, which directly puts vinyl cyclic siloxanes for random copolymerization. By dynamically loading the novel phosphazene catalyst and implementing gradient temperature control in the multi-stage series microfluidic reaction units, the vinyl monomers and other siloxane monomers complete precise positioning copolymerization during the continuous flow process. This fundamentally avoids the deactivation and local agglomeration of vinyl groups from the source of the reaction, increasing the retention rate of vinyl groups during polymerization from 68% of the traditional process to 99.1%, and thoroughly solving the gelation problem that easily occurs in the production of high-vinyl silicone oil. Second, China's first six-stage gradient purification system for high-vinyl systems has been built. Aiming at the difficulty of separating small molecule cyclic siloxanes in high-vinyl silicone oil, the team innovatively adopted a combined purification process of "two-stage thin-film evaporation + three-stage short-path molecular distillation + supercritical fluid deep extraction + molecular sieve adsorption". The separation is completed in a mild environment not exceeding 90°C throughout the process, which does not damage the activity of vinyl groups at all. The volatile content of the final product after constant temperature baking at 150°C for 3 hours is only 0.02%, far lower than the average level of 0.7% of traditional process products, fully meeting the most stringent requirements of EU REACH regulations for low-VOC medical-grade organosilicon materials. Third, a full-process millisecond-level real-time closed-loop quality control system has been built. Online Raman spectroscopy and online nuclear magnetic resonance detection modules are deployed in the entire process of polymerization, purification, final mixing and filling of the complete production unit. The system samples and analyzes the vinyl content, viscosity and active group concentration of the reaction system in real time every 8 seconds. Once the parameters have a slight deviation, the system automatically makes dynamic adjustments, completely eliminating the product performance difference between different reactors in the traditional batch process, and realizing zero performance drift of products from different batches across years.
At present, this independently developed ultra-high-purity high-vinyl silicone oil has completed long-term industrial application verification for more than 24 months in multiple core high-end downstream fields. In the field of photovoltaic new energy, the two-component addition-cured photovoltaic encapsulant prepared with this product has a 47% improvement in the uniformity of crosslinking density. After UV aging and -40°C to 85°C hot and cold cycle tests, the tensile strength retention rate of the encapsulant reaches 94%, and the yellowing index is only 0.6, far lower than the 3.0 required by industry standards. The outdoor long-term power generation life of N-type photovoltaic modules has been extended from 25 years to 36 years. Related products have been fully and batch applied in the new-generation TOPCon and HJT module production lines of mainstream domestic photovoltaic module enterprises. In the field of high-end medical silicone rubber, this low small-molecule residual vinyl silicone oil has passed the full set of biocompatibility tests of ISO10993 and long-term implantation safety certification. As a base polymer, it prepares medical silicone rubber that will not cause small molecule precipitation and performance degradation after being implanted in the human body for more than 5 years. Related products have been applied in Class III medical device fields such as artificial breast, soft tissue filling and interventional catheters. In the field of special electronic potting, the high-thermal-conductivity silicone gel prepared with this product as the core raw material has a stable thermal conductivity of 3.2W/(m·K) and an electrical breakdown strength exceeding 25kV/mm. After 1000 power cycle tests, no interface delamination occurs, and it has been widely used in the thermal potting scenarios of new energy vehicle power batteries and IGBT modules of AI computing servers. In the aerospace field, the environment-resistant silicone rubber prepared with this product can maintain stable elasticity and mechanical properties in the wide temperature range of -70°C to 220°C, and has been applied in the sealing and shock absorption components of new-generation aircraft.
According to the latest industry operation data, the market demand for domestic high-vinyl silicone oil in 2026 increased by 263% year-on-year compared with the same period in 2025. With the launch of this domestic continuous production line, the market pattern where overseas products once occupied an absolute dominant position has been completely broken. The market procurement price of high-end high-vinyl silicone oil has dropped by 67% year-on-year, and the delivery cycle for core downstream users has been shortened from the original 10 months to less than 7 days. With the subsequent start of construction of the second production line of the same scale, it is expected that by 2028, the global market share of domestically produced high-end high-vinyl silicone oil will exceed 75%. It will not only fully meet the upgrading needs of domestic downstream industries, but also greatly enhance the core voice of China's organosilicon key intermediates in the global industrial chain, and build a solid raw material foundation for the innovative development of the entire organosilicon downstream new material industry.
