I. Strategic Value Upgrading of the Hydroxyl Silicone Oil Industry: From General Auxiliary to Core Intermediate for High-End Manufacturing‌

        Hydroxyl silicone oil is a class of organosilicon compounds with polydimethylsiloxane as the main chain and reactive hydroxyl functional groups on both ends or side chains of the molecular chain. As one of the most important functional intermediates downstream of organosilicon monomers, its industrial development has always been deeply bound to the green transformation of global fine chemical and high-end manufacturing industries. Different from traditional inert methyl-terminated dimethyl silicone oil, the reactive hydroxyl groups on the molecular chain of hydroxyl silicone oil can participate in various chemical reactions such as crosslinking, grafting, and condensation. It can not only be directly used as a functional auxiliary, but also serve as a matrix to further synthesize various downstream derivative products such as modified silicone oil, silicone rubber, and silicone resin. It is a key hub category that connects the preceding and following links in the entire organosilicon material industry chain.
        For a very long period in the past, the product structure of China's hydroxyl silicone oil industry was long-term biased towards low-end general grades. The industry generally positioned it as an ordinary auxiliary raw material in the fields of construction sealants and textile auxiliaries, with low added value and slow technological iteration. With the rapid rise of strategic emerging industries such as new energy, semiconductors, and high-end industrial coatings in China, the market demand for high-purity, customized hydroxyl silicone oil continues to explode, and its industrial positioning has also undergone a fundamental transformation: from the past general bulk auxiliary to a core functional intermediate that supports the independent controllability of materials in multiple high-end manufacturing fields.
        According to the High-Quality Development White Paper of the Organosilicon Industry released by the China Petroleum and Chemical Industry Federation in 2026, the domestic market size of hydroxyl silicone oil increased from 38.7 billion yuan to 57.4 billion yuan from 2021 to 2025, with an average annual compound growth rate of 8.2%. It is expected that the annual market size will exceed 62.1 billion yuan in 2026. Among them, the demand growth rate of high-end segmented grades such as electronic grade and high hydroxyl value has remained above 15% for three consecutive years, far higher than the industry average growth rate. The core driving force of industrial growth has shifted from the stock replacement in traditional construction and textile fields to the incremental expansion in high-end emerging fields.

‌II. Iteration of Synthesis Technology: From Traditional Hydrolysis Cracking to the Full Implementation of Continuous Green Manufacturing System‌
        The industrial production of hydroxyl silicone oil in China first started in the 1970s. The traditional mainstream production process takes the hydrolysis cracking reaction of dimethylcyclosiloxane as the core, and hydroxyl silicone oil is prepared through the ring-opening equilibrium reaction between water and cyclosiloxane in an intermittent reactor. This traditional process has three long-term unsolvable common industry pain points: first, the equilibrium conversion rate of the reaction process can only reach a maximum of about 72%, and a large amount of unreacted cyclosiloxane monomers remain in the system, which requires multiple high-vacuum distillation processes for subsequent removal, resulting in extremely high production energy consumption. The comprehensive energy consumption per unit product is long-term higher than 2.3 tons of standard coal per ton; second, the hydroxyl end-capping rate during the reaction process is difficult to accurately control, and the molecular weight distribution index of the final product is generally higher than 1.8, with a batch-to-batch viscosity deviation rate of more than 25%, which cannot meet the strict requirements of high-end application scenarios for product consistency; third, the production process of the traditional intermittent process has an extremely low level of automation, the single-batch production cycle exceeds 48 hours, there are many unorganized emission points of volatile organic compounds (VOCs) during the production process, and the environmental governance pressure is extremely high.
         In the past five years, R&D teams in China's organosilicon industry have targeted the common pain points of traditional processes and completed full-chain technological subversive innovation, developing a ‌continuous ionic catalytic ring-opening - thin-film devolatilization coupling process system‌ with completely independent intellectual property rights, completely breaking the performance and cost ceiling of traditional processes. This new process integrates multiple independent processes of traditional intermittent production into a fully continuous closed-loop production system: in the continuous ring-opening reaction unit, a high-activity supported solid ionic catalyst is used to replace the traditional liquid acid/alkali catalyst. The catalyst and the reaction system can realize automatic online separation, no subsequent neutralization and water washing processes are required, eliminating the generation of saline wastewater from the source; in the precise molecular chain regulation unit, through segmented temperature gradient and precise metering control of trace water, directional regulation of the hydroxyl end-capping rate is realized, and the molecular weight distribution index of the final product can be stably controlled in the range of 1.1-1.3, far better than the industry average level of traditional processes; in the multi-stage thin-film devolatilization unit, three-stage series molecular distillation technology is adopted to control the residual cyclosiloxane monomer content in the product below 100ppm, far lower than the level of more than 1000ppm in traditional processes.
         The full implementation of this new process system has reduced the comprehensive energy consumption per unit product by 68%, reduced VOC emissions during the production process by 92%, compressed the product production cycle from 48 hours to less than 6 hours, and increased the product qualification rate from less than 75% of the traditional process to more than 99.2%. The relevant core technical achievements have been included in the 3rd issue of Organosilicon Materials journal in 2026, and the overall process technology level has reached the international leading level, completely solving the three core problems of purity, consistency and green production that have long restricted the large-scale promotion of high-end hydroxyl silicone oil. As of the second quarter of 2026, more than 60% of the new hydroxyl silicone oil production capacity in China has adopted this continuous green process, and the overall green manufacturing level of the industry has achieved leapfrog improvement.

‌III. High-End Evolution of Product Structure: Multi-Dimensional Segmented Grades Cover Full-Scenario Application Requirements‌
        With the comprehensive upgrading of synthesis processes, the product classification system of domestic hydroxyl 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 constructed from three dimensions: hydroxyl position, purity grade and functional attribute, which can accurately match the differentiated needs of different downstream scenarios.
        Divided from the dimension of hydroxyl position, products can be classified into two major categories: terminal hydroxyl type and side hydroxyl type. The reactive hydroxyl groups of terminal hydroxyl type hydroxyl silicone oil are concentrated at the two ends of the molecular chain, which can realize linear directional chain extension during the reaction process, and is the core raw material in the fields of RTV silicone rubber and textile softening finishing agents; the reactive hydroxyl groups of side hydroxyl type hydroxyl silicone oil are evenly distributed on the side chains of the molecular chain, which can provide multiple reactive sites at the same time, and the reaction efficiency of graft modification with organic resin is more than 2 times higher than that of terminal hydroxyl products, making it the preferred modified auxiliary in the fields of high-end industrial coatings and inks.
        Divided from the dimension of purity grade, products can be divided into three core grades: industrial grade, electronic grade and pharmaceutical grade. The total metal ion content of industrial grade hydroxyl silicone oil is controlled below 50ppm, which can meet the application requirements of general scenarios such as construction sealants and ordinary textile auxiliaries; the total metal ion content of electronic grade hydroxyl silicone oil is controlled below 5ppm, and the chloride ion impurity content is less than 1ppm, which can be directly used in scenarios with strict impurity content requirements such as semiconductor chip packaging adhesives and new energy power battery adhesives; the biocompatibility index of pharmaceutical grade hydroxyl silicone oil has passed the certification of the domestic pharmaceutical supervision system, and can be directly used in fields related to human contact such as medical silicone rubber products and pharmaceutical excipients.
        Divided from the dimension of functional attributes, the industry has developed more than ten kinds of customized functional products such as low-viscosity and high-hydroxyl value grades, high-compatibility linear grades, and low-volatility and low-cyclic grades. The hydroxyl value of low-viscosity and high-hydroxyl value grades can reach more than 45mgKOH/g, which can be used as a high-reactivity crosslinking agent to greatly improve the curing reaction efficiency of silicone rubber; the molecular chains of high-compatibility linear grades are highly regularly arranged, which greatly improves the compatibility with organic resins such as acrylic resin and epoxy resin, completely avoiding the common problems of traditional auxiliaries such as precipitation and interlayer adhesion decline; the total volatile content of low-volatility and low-cyclic grades is less than 0.1%, which can meet the extreme requirements for VOC emissions in application scenarios such as automotive interiors and high-end electronic components.
        The construction of a refined product pedigree has completely opened the application boundary of hydroxyl silicone oil. At present, there are more than 70 segmented product grades of domestic hydroxyl silicone oil, which can cover all scenario requirements from traditional civil fields to high-end strategic emerging industries. The self-sufficiency rate of high-end products has increased from 42% in 2021 to 68% in 2026, completely changing the industrial pattern that high-end hydroxyl silicone oil has long relied on imports in the past.

‌IV. In-Depth Penetration of Downstream Applications: Technology Value Release and Industrial Collaboration in Six Core Fields‌
        With the continuous improvement of the performance of hydroxyl silicone oil products, its downstream application scenarios are deeply penetrating from the three traditional fields to more high value-added tracks. At present, it has achieved large-scale implementation in six core fields: construction sealants, textile printing and dyeing, coatings and inks, electrical and electronics, new energy, daily chemicals and medicine, promoting the completion of green technological upgrading of products in multiple downstream industries.
        In the field of ‌construction sealants‌, hydroxyl silicone oil, as the core structure control agent of RTV silicone rubber, can effectively inhibit the structuring reaction between white carbon black and silicone raw rubber, prevent the adhesive from hardening and losing fluidity during storage, and greatly extend the shelf life and service life of sealant products. With the continuous improvement of domestic construction's requirements for durability and environmental protection of sealing materials, high-end hydroxyl silicone oil with low volatility and high stability has become the standard raw material for high-end neutral silicone sealants, pushing the average service life of domestic construction sealant products from the past 10 years to more than 25 years.
        In the field of ‌textile printing and dyeing‌, the new soft finishing agent prepared with hydroxyl silicone oil as the core raw material can form stable hydrogen bond bonds with hydroxyl, amino and other groups on the fiber surface through reactive hydroxyl groups. Compared with the traditional inert methyl silicone oil that only adheres to the fiber surface by physical adsorption, its washing resistance is improved by more than 50%. After 50 washes, the fabric can still maintain excellent smooth and fluffy handfeel, without destroying the moisture absorption and air permeability of the fabric itself, perfectly adapting to the upgrading needs of current consumers for the wearing comfort of high-end textiles.
        In the field of ‌coatings and inks‌, with the characteristic of participating in crosslinking reactions, hydroxyl silicone oil can be directly connected to the crosslinking network of coating resins, completely solving the long-term industry pain points of traditional ordinary silicone oils used as leveling auxiliaries, which are easy to precipitate, leading to the decline of coating recoating adhesion and the occurrence of shrinkage cavities and orange peel defects. At present, this type of modified hydroxyl silicone oil has been widely used in high-end industrial paints, coil coatings, and food contact packaging inks, which can effectively improve the surface smoothness, scratch resistance and weather resistance of coatings, and promote the overall quality of domestic industrial coatings to approach the international advanced level.
        In the field of ‌electrical and electronic‌, ultra-high-purity hydroxyl silicone oil is used as the core raw material for electronic-grade silicone gel and potting adhesives. The prepared electronic potting materials have excellent insulation properties, thermal stability and thermal shock resistance, and can work stably for a long time in the extreme temperature environment from -60℃ to 200℃. It is widely used in the packaging and protection links of power semiconductor modules, high-voltage electrical components, and consumer electronic motherboards, greatly improving the long-term operation reliability of electronic devices.
        In the field of ‌new energy‌, hydroxyl silicone oil is widely used in the production of power battery structural sealants and photovoltaic module encapsulants. Its characteristics of low volatility and high weather resistance can effectively prevent sealing materials from releasing small molecular substances to corrode battery chips and photovoltaic cells during long-term use, greatly extending the full life cycle service life of new energy equipment. In 2025, the apparent consumption of hydroxyl silicone oil in the domestic new energy field increased by 27.6% year-on-year, and it has become the downstream track with the fastest growth rate in the industry.
        In the field of ‌daily chemicals and medicine‌, purified low-viscosity hydroxyl silicone oil is used in the formulations of high-end skin care and hair care products. It can form a breathable flexible protective film on the surface of skin and hair, which can achieve a smooth use feel without clogging pores, and the market acceptance of related products is continuing to increase rapidly.
        The in-depth penetration of the six core fields has built a benign ecosystem of collaborative upgrading between the hydroxyl silicone oil industry and downstream application industries. According to industry association statistics, in the downstream demand structure of domestic hydroxyl silicone oil in 2025, construction sealants accounted for 33.7%, textile printing and dyeing 18.2%, coatings and inks 17.5%, electrical and electronics 12.4%, new energy 11.2%, daily chemicals, medicine and other fields 7%. The demand structure has realized the transformation from traditional domain-led development to collaborative development of multiple high-end fields.

‌V. Future Development Trend of the Industry: Continuous Evolution Towards Low-Carbon, High-Value and Globalization‌
        Looking forward to 2026-2030, under the background of the continuous advancement of the domestic "dual carbon" strategy and the continuous implementation of the first batch of application demonstration policies for new materials, the hydroxyl silicone oil industry will enter a brand new stage of high-quality development. The development focus of the industry will fully shift from the past "scale expansion" to "value improvement". In the next few years, almost all new production capacity in the industry will be oriented to high-purity, customized high-end segmented grades. It is expected that the output proportion of high-purity hydroxyl silicone oil in China will exceed 25% in 2026, and the total production capacity of the whole industry will reach 315,000 tons per year.
        At the same time, the entire industry will fully promote the construction of a carbon footprint management system, further reduce the carbon emission intensity per unit product through continuous optimization of production processes and cyclic resource utilization of by-products, and promote the entire hydroxyl silicone oil industry to complete the low-carbon green transformation. With the continuous improvement of the international competitiveness of domestic products, the export market of hydroxyl silicone oil will also further expand. The export destinations of products will gradually expand from traditional emerging markets such as Southeast Asia and the Middle East to high-end markets in Europe and North America, promoting China's hydroxyl silicone oil industry to achieve a strategic leap from "leading in scale" to "leading in technology" in the global organosilicon industry chain.