‌‌I. Strategic Positioning Upgrading of the Phenyl Silicone Oil Industry: From Special Auxiliary Material to Core Guarantee Material for Extreme Working Conditions‌

        Phenyl silicone oil is a class of special functional organosilicon materials formed by replacing part of the methyl groups in the molecular chain of methyl silicone oil with phenyl groups. It is one of the core categories with the highest technical barriers and the most demanding application scenarios in the high-end special silicone oil system. Different from ordinary methyl silicone oil, which can only work stably for a long time in the conventional temperature range of -50℃ to 180℃, phenyl silicone oil has achieved qualitative breakthroughs in multiple dimensions such as high and low temperature resistance, radiation resistance, arc resistance, compatibility and optical transparency thanks to the phenyl functional groups introduced into its molecular chain. It is one of the few organosilicon materials that can simultaneously adapt to extreme working conditions such as ultra-low temperature cryogenic environments, long-term high temperature environments above 250℃, and strong ionizing radiation environments.
         For a very long period in the past, China's phenyl silicone oil industry was long in an unbalanced state of "excess low-end grades and blank high-end categories". The industry generally positioned it as a niche special auxiliary, only used in a small number of segmented scenarios such as high-end lubricating oils and special coatings, and the overall market size remained at a low level for a long time. With the rapid advancement of high-end strategic fields such as aerospace, third-generation semiconductors, nuclear fusion engineering, and deep space exploration in China, the demand for independent and controllable materials under extreme working conditions has fully exploded, and the industrial positioning of phenyl silicone oil has been completely upgraded: from the past niche special auxiliary material, it has transformed into a core guarantee material that supports the long-term stable operation of major national engineering equipment.
        According to the Blue Book for the Development of Special Organosilicon Material Industry released by the China Fluorine and Silicon Organosilicon Industry Association in 2026, the domestic market size of phenyl silicone oil increased from 1.26 billion yuan to 2.39 billion yuan from 2021 to 2025, with an average annual compound growth rate as high as 17.4%, which is 2.7 times the growth rate of the ordinary methyl silicone oil industry. It is expected that the annual market size will exceed 2.87 billion yuan in 2026. Among them, the demand growth rate of high-end segmented grades such as high phenyl content and low-volatility electronic grade has remained above 25% for four consecutive years, far higher than the industry average. The core driving force of industrial growth has shifted from the stock replacement in traditional high-end civil scenarios to the rigid incremental demand in major national engineering fields.

‌II. Full-Chain Technical Breakthrough in Synthesis Process: From Traditional Intermittent Reaction to the Implementation of a Controllable Synthesis System with Precise Molecular Structure‌
        China's industrial exploration of phenyl silicone oil first started in the 1980s. The traditional mainstream production process takes the co-hydrolysis - equilibrium polymerization reaction of methylphenyl dichlorosilane and dimethyl dichlorosilane as the core, and phenyl silicone oil products are prepared through acid-catalyzed ring-opening polymerization in an intermittent reactor. This traditional process has three long-term unsolvable common technical bottlenecks in the industry: first, the distribution of phenyl functional groups in the molecular chain is completely random, and a large number of phenyl groups are concentrated in the local area of the molecular chain, which easily leads to local crystallization of the molecular chain and greatly deteriorates the low-temperature performance of the product. Phenyl silicone oil produced by ordinary traditional processes will solidify at -40℃, which completely fails to meet the usage requirements of cryogenic scenarios; second, it is extremely difficult to accurately control the phenyl content during the reaction process. The phenyl content deviation rate of the final product is generally more than 12%, and the key indicators such as temperature resistance and refractive index of products from different batches have extremely poor consistency, which cannot meet the scenarios with extremely high requirements for material performance stability such as optics and semiconductors; third, the products produced by traditional processes retain a large amount of unreacted phenyl cyclosiloxane monomers, and the subsequent high-vacuum devolatilization process is far more difficult to remove than ordinary methyl cyclosiloxane. The total volatile content of the final product is long-term higher than 2%, which completely fails to meet the extreme requirements for low material volatility in scenarios such as aerospace and high-vacuum equipment.
        In the past five years, the core R&D teams in China's organosilicon field have targeted the three common pain points of traditional processes and completed full-chain technological subversive innovation, developing a ‌gradient controllable phenyl distribution - continuous catalytic polymerization - multi-stage molecular distillation deep devolatilization coupling process system‌ with completely independent intellectual property rights, completely breaking the decades-long technological monopoly of foreign enterprises in the field of high-end phenyl silicone oil. This new process system has achieved fundamental breakthroughs in three core dimensions: in the precise molecular chain structure regulation unit, the segmented gradient feeding technology is adopted, and methylphenyl cyclosiloxane and dimethyl cyclosiloxane in different proportions are gradually injected into the continuous reaction system according to the preset procedure, realizing the uniform distributed arrangement of phenyl functional groups on the entire polysiloxane molecular chain, fundamentally avoiding the low-temperature crystallization problem caused by local phenyl enrichment from the molecular structure level. The low-temperature freezing point of the final product can be stably controlled below -70℃; in the continuous catalytic polymerization unit, a highly selective supported solid superacid catalyst is used to replace the traditional liquid acid catalyst, and the directional selectivity of the catalytic reaction is increased to 98.7%. The phenyl content deviation rate of the product can be controlled within 1.5%, and the refractive index deviation of products from different batches is less than 0.002, with performance consistency reaching the international leading level; in the multi-stage deep devolatilization unit, a three-stage series combination process of high-vacuum short-path molecular distillation and thin-film devolatilization is adopted, which can control the total content of residual cyclosiloxane monomers in the product below 50ppm, and the total volatile content of the product is less than 0.1%, far better than the industry average level of traditional processes.
        The full implementation of this new process system has reduced the production energy consumption per unit product of high-end phenyl silicone oil by 72%, and the comprehensive qualified rate of products has increased from less than 58% of the traditional process to 98.5%, completely solving the three core problems that have long restricted the large-scale application of domestic high-end phenyl silicone oil: uncontrollable molecular structure, poor batch consistency and high volatile content. The relevant core technical achievements have been included in the 4th issue of Organosilicon Materials journal in 2026, and the overall process technology level has reached the international advanced level. As of the second quarter of 2026, more than 75% of the new phenyl silicone oil production capacity in China has adopted this new independent and controllable process, completely ending the industrial history that domestic high-end phenyl silicone oil has long relied on imports.

‌III. Fine Construction of Product Pedigree: Multi-Gradient Phenyl Content Covering the Demand of Full-Scenario Extreme Working Conditions‌
        With the comprehensive breakthrough of synthesis technology, the product classification system of domestic phenyl silicone oil has completed fine reconstruction, completely getting rid of the extensive mode that only divides products by the single index of viscosity in the past, and forming a complete product pedigree with the molar fraction of phenyl as the core dimension, combined with purity grade and functional attribute, which can accurately match the differentiated needs of different extreme working condition scenarios.
        Divided by the core dimension of phenyl molar fraction, products can be classified into three core categories: low-phenyl, medium-phenyl and high-phenyl. The low-phenyl phenyl silicone oil has a phenyl molar fraction in the range of 5%-10%, and its low-temperature performance is the most prominent. It can maintain a liquid flow state for a long time in an ultra-low temperature environment of -70℃, and has excellent shear resistance. It is the preferred material for aviation instrument oil in alpine regions and lubricating oil for cryogenic equipment; the medium-phenyl phenyl silicone oil has a phenyl molar fraction in the range of 20%-30%, and its products achieve a perfect balance of temperature resistance, radiation resistance and optical performance. It can work stably for a long time in a high temperature environment of 220℃, and has excellent visible light transmittance at the same time. It is the core raw material for high-end optical lens release agents and hydraulic oils under high temperature working conditions; the high-phenyl phenyl silicone oil has a phenyl molar fraction in the range of 40%-50%, and its radiation resistance, arc resistance and high temperature resistance reach the peak. It can be used for a long time at high temperatures above 250℃, and can withstand strong ionizing radiation of 1×10^7Gy. It is the core supporting material for extreme working condition components in nuclear industry equipment, nuclear fusion devices, and deep space exploration spacecraft.
        Divided by the dimension of purity grade, products can be divided into three core grades: industrial grade, electronic grade and aerospace grade. The total metal ion content of industrial grade phenyl silicone oil is controlled below 30ppm, which can meet the usage requirements of general high-end scenarios such as special lubricating oils and ordinary high-temperature coatings; the total metal ion content of electronic grade phenyl silicone oil is controlled below 3ppm, the chloride ion impurity content is less than 0.5ppm, and the total volatile content is less than 0.2%. It can be directly used in electronic and electrical scenarios with strict impurity content requirements such as third-generation semiconductor power device packaging and high-voltage insulation component potting; the total volatile content of aerospace grade phenyl silicone oil is less than 0.1%, which has been verified by high-vacuum outgassing test and fully meets the high-vacuum usage environment requirements of aerospace equipment. It can be directly applied to core links such as lubrication of moving parts of spacecraft and damping of optical systems.
        Divided by the dimension of functional attributes, the industry has developed more than ten kinds of customized functional products such as low-viscosity and high-transparency grades, high radiation-resistant grades, and high-refractive-index optical grades. The visible light transmittance of low-viscosity and high-transparency grades exceeds 99%, and the transmittance in the near-ultraviolet band of 300nm can also reach more than 90%, which can be used as a high-end optical coupling agent; the high radiation-resistant grade has been optimized by special molecular structure, and no viscosity sharp rise problem caused by molecular chain scission and crosslinking will occur in a strong ionizing radiation environment, and its service life is more than 3 times that of ordinary phenyl silicone oil; the refractive index of the high-refractive-index optical grade can be stably controlled in the range of 1.50-1.55, which can be directly used as the filling medium of high-end optical lenses, greatly improving the imaging quality of the optical system.
        The construction of a refined product pedigree has completely opened the application boundary of phenyl silicone oil. At present, there are more than 50 segmented product grades of domestic phenyl silicone oil, which can cover all requirements from high-end civil fields to extreme working condition scenarios of major national engineering projects. The self-sufficiency rate of high-end products has increased from 21% in 2021 to 72% in 2026, completely reversing the industrial pattern that domestic high-end special phenyl silicone oil has long been monopolized by overseas products.

‌IV. In-Depth Expansion of Downstream Applications: Technology Value Release and Industrial Collaboration in Six Core Extreme Scenarios‌
        With the continuous improvement of the performance of phenyl silicone oil products, its downstream application scenarios are deeply penetrating from the traditional high-end lubricating oil track to multiple extreme working condition scenarios related to major national engineering projects. At present, it has achieved large-scale implementation in six core fields: aerospace, nuclear industry equipment, third-generation semiconductors, high-end optics, special lubrication, and high-end coatings and inks, promoting the independent and controllable upgrading of material systems for extreme working conditions in multiple high-end manufacturing fields.
        In the field of ‌aerospace‌, aerospace-grade phenyl silicone oil with low phenyl content is widely used as the pressure transmission medium of aviation instruments flying in alpine regions, and the base oil of damping grease for the deployment mechanism of spacecraft solar panels. Its excellent high and low temperature resistance can ensure that the damping torque of moving parts always remains stable in the wide temperature range of -65℃ to 200℃, and there will be no failure problems such as solidification or thinning of ordinary lubricating oils at extreme temperatures, greatly improving the operation reliability of aerospace equipment in the full working condition environment.
        In the field of ‌nuclear industry equipment‌, special phenyl silicone oil with high phenyl content is used as the lubricating medium for the moving parts of the core control mechanism of nuclear reactors. Its excellent strong ionizing radiation resistance can maintain stable lubricating performance for a long time in the strong radiation environment inside the reactor, and will not cause the problem of rapid aging and failure of ordinary organic materials in the radiation environment, greatly extending the maintenance cycle and service life of the core moving parts of nuclear equipment.
        In the field of ‌third-generation semiconductors‌, ultra-high-purity medium-phenyl phenyl silicone oil is used as the core modified component of high-temperature encapsulating adhesives for silicon carbide power devices, which can greatly improve the thermal stability and insulation performance of encapsulating materials in a long-term working environment above 200℃, and avoid the performance degradation problem of encapsulating materials modified by ordinary methyl silicone oil in a long-term high temperature environment. It perfectly adapts to the high-temperature working characteristics of third-generation semiconductor power devices, greatly improving the long-term operation reliability of high-voltage power modules in new energy vehicles, rail transit and other fields.
        In the field of ‌high-end optics‌, medium-phenyl phenyl silicone oil with high refractive index is used as the filling medium of high-end optical lenses and the high-efficiency release agent for precision optical lenses. Its excellent optical uniformity and extremely low surface tension can form an extremely thin uniform isolation layer on the surface of optical lenses during the demolding process, leaving no residual traces on the lens surface, greatly improving the production yield of high-end optical lenses. At present, this type of product has been widely used in many domestic high-end optical lens manufacturing enterprises.
        In the field of ‌special lubrication‌, phenyl silicone oil with different gradient phenyl contents is widely used as the base oil for high-temperature chain oils, high-speed bearing greases, and extreme working condition gear oils. Compared with traditional mineral-based lubricating oils, its maximum service temperature is increased by more than 100℃, and it has excellent anti-oxidation stability, which can greatly extend the oil change cycle of lubricating greases, and has been widely promoted in industrial scenarios that are in long-term high temperature working conditions such as iron and steel metallurgy and glass manufacturing.
        In the field of ‌high-end coatings and inks‌, modified phenyl silicone oil is used as a functional auxiliary for high-temperature resistant coatings, which can greatly improve the high temperature resistance, arc resistance and surface smoothness of coating layers. The prepared high-temperature resistant organosilicon coatings can be used for a long time at 300℃ without yellowing or falling off, and are widely used in protective coating of special scenarios such as the outer shell of aero-engines and the inner wall of high-temperature industrial kilns.
        The in-depth penetration of the six core fields has built a benign ecosystem of collaborative upgrading between the phenyl silicone oil industry and the high-end extreme manufacturing industry. According to statistics from industry associations, in the downstream demand structure of domestic phenyl silicone oil in 2025, the special lubrication field accounted for 28.3%, the aerospace field 22.7%, the nuclear industry and high-end equipment field 15.1%, the third-generation semiconductor field 14.6%, the high-end optical field 10.2%, and the high-end coatings, inks and other fields 9.1%. The demand structure has realized a comprehensive transformation from the traditional industrial auxiliary field-led development to the core guarantee field of major national engineering projects.

‌V. Future Development Trend of the Industry: Continuous Evolution Towards Customization for Extreme Working Conditions, Full-Chain Independence and High-End Export‌
        Looking forward to 2026-2030, under the background of the continuous advancement of multiple major national science and technology projects and the continuous implementation of the first batch of application insurance compensation mechanisms for new special materials, the phenyl silicone oil industry will enter a new stage of high-quality development. The development focus of the industry will fully shift from the past "filling in the blanks" to "extreme performance customized development". In the next few years, almost all new production capacity in the industry will be oriented to high-purity, special customized special grades for extreme working conditions. It is expected that the output proportion of high-end phenyl silicone oil in China will exceed 32% in 2026, and the total production capacity of the whole industry will reach 48,000 tons per year.
        At the same time, the entire industry will continue to exert efforts on the development of downstream derivative products of phenyl silicone oil, further developing a series of high-end derivative special organosilicon materials such as phenyl silicone rubber, phenyl silicone resin, and phenyl silicone gel based on phenyl silicone oil as the base matrix, and building a complete independent industrial system of phenyl-based special organosilicon materials. With the continuous improvement of the international competitiveness of domestic products, the export market of phenyl silicone oil will also further expand. The export destinations of products will gradually expand from traditional emerging markets to high-end equipment manufacturing markets in Europe and North America, promoting China's phenyl silicone oil industry to achieve a strategic leap from "following and catching up" to "leading in some fields" in the global high-end special organosilicon industry chain.