The difference between silicone and silicone rubber
    Silicone rubber has been widely used, but some people may not understand and distinguish between silicone rubber and silica gel, and the name is not fixed. Today, the editor will introduce the difference and classification of silicone and silicone rubber in detail. At present, the concept of the term "silicone" is not standardized, because so far there is no state clearly defined name. When we hear the word "silica gel", we must understand whether it is silica or silicon-containing synthetic rubber, or in the final analysis, it is inorganic silica gel or organic silica gel.

    "Silica gel" is called by several related words: silicone rubber, silicone rubber, silicone. The relationship between silicone rubber and silica gel is different from silicone rubber and includes silicone rubber. Silicone rubber is the organic "silica gel" in "silica gel". "Silicone" is the term used by Hong Kong and Taiwan. In mainland China, it is called "silicone". Silicone and Silicone are the transliterations of English silicone. We usually say that it also means "silicone."

    In summary, silica gel can be divided into two categories: organic silica gel and inorganic silica gel according to its properties and components.

    1. Performance and technical parameters of silicone rubber


    Silicone rubber is the largest and most widely used category of silicone products. After vulcanization, silicone rubber has excellent high temperature resistance, low temperature resistance, weather resistance, water repellency, electrical insulation, and physiological inertia.

    The main properties and applications of silicone rubber products: according to its vulcanization temperature, silicone rubber can be divided into two categories: high temperature (heating) vulcanization and room temperature vulcanization. High temperature rubber is mainly used to manufacture various silicone rubber products, while room temperature rubber is It is mainly used as an adhesive, potting material or mold.

    Hot Vulcanized Silicone Rubber (HTV)

    Thermally vulcanized silicone rubber (HTV) is the most important category of silicone products, and methyl vinyl silicone rubber (VMQ) is the most important category in HTV, commonly known as high temperature rubber. Methyl vinyl silicone rubber (raw rubber) is a colorless, odorless, non-toxic, and no mechanical impurities. The raw rubber is mixed with appropriate reinforcing agents, structure control agents, vulcanizing agents and other additives as needed. Refining, then heating and compression molding or extrusion molding, and then two-stage vulcanization into various products. Its products have excellent electrical insulation, strong resistance to arc, corona, and spark, waterproof, moisture-proof, impact resistance, shock resistance, physiological inertia, air permeability and other properties. Mainly used in aviation, instrumentation, electronics and electrical appliances, navigation, metallurgy, machinery, automobiles, medical and health and other departments, can be used to make various shapes of sealing rings, gaskets, tubes, cables, and can also be used as human organs, blood vessels, breathable membranes and Rubber molds, mold release agents for precision casting, etc.

    Room temperature vulcanized silicone rubber (RTV)

    RTV silicone rubber generally includes two categories: condensation type and addition type. "Addition type room temperature glue is based on linear polysiloxane with vinyl group, hydrogen-containing siloxane is used as crosslinking agent, and crosslinking reaction occurs at room temperature to medium temperature in the presence of a catalyst to become an elastomer. It has good heat resistance, water repellency, and electrical insulation. At the same time, due to the introduction of active end groups, it has excellent physical and mechanical properties, especially in tensile strength, relative elongation and tear strength. The improvement. It is suitable for a variety of vulcanization methods, such as radiation vulcanization, peroxide vulcanization, and addition molding vulcanization. It is widely used in heat resistance, moisture resistance, electrical insulation, and high-strength silicone rubber products.

    Condensation-type room temperature vulcanized silicone rubber is characterized by the condensation reaction between silicone hydroxyl and other active materials, which can be cross-linked to become elastomers at room temperature. The products are divided into one-component packaging and two-component packaging. form. One-component room temperature vulcanized silicone rubber (RTV-1 rubber for short) is one of the main products in condensed liquid silicone rubber. It is usually formulated from basic polymers, crosslinking agents, catalysts, fillers and additives. The product is packaged in a sealed hose, squeezed out during use, and can be vulcanized into an elastomer after being exposed to air, which is extremely convenient to use. The vulcanizate can be used for a long time in the temperature range of (-60～+200℃), has excellent electrical insulation properties and chemical stability, is resistant to water, ozone, weathering, and has good adhesion to a variety of metal and non-metal materials. Accessibility. It is mainly used for the coating of various electronic components and electrical equipment. The encapsulating material plays the role of insulation, moisture-proof and shock-proof; as a surface protection material for semiconductor devices; also as a sealing filler and elastic adhesive.

  Two-component room temperature vulcanized silicone rubber (RTV-2 rubber for short) is not as convenient as RTV-1 rubber, but its component ratio is rich in changes. One variety can obtain vulcanized products with multiple specifications and properties, and it can also be deeply vulcanized. Therefore, it is widely used as materials for insulation, encapsulation, caulking, sealing, moisture-proof, anti-vibration and roller making in industries such as electronics, automobiles, machinery, construction, textile, chemical, light industry, printing and so on. In addition, because RTV-2 has excellent mold release properties, it is widely used as a soft mold material for the reproduction and manufacture of cultural relics, handicrafts, toys, electronic appliances, and mechanical parts.

    One of the typical applications of silicone sealants is glass curtain walls. The glass and aluminum alloy frame are bonded with organic silicon structural adhesive as the exterior wall material, and the expansion joint is waterproof and sealed with organic silicon weather-resistant adhesive. Other applications include the peripheral sealing of aluminum alloy doors and windows and plastic steel doors and windows, the joints of glass installation and moving grooves, the sealing of rivets and fixing screws: sanitary ware and countertops, walls, and furniture in kitchens, bathrooms, and toilets. Waterproof seal between the aquariums, ceilings, metal roofs, showcases, counters, wall panels, color steel plates; used for waterproof caulking seals between high-grade highway plates, etc.

    In addition to sealants for construction, RTV also includes sealing materials used in aerospace, nuclear power plants, electronics, machinery, automobiles and other industries, silicone potting materials used for potting electronic components, and silicone used as soft mold materials Mold glue and so on. The demand for these varieties is relatively small, but they are indispensable on many occasions.

  Inorganic silica gel (silica gel)

    Inorganic silica gel is a highly active adsorption material, which is usually prepared by reacting sodium silicate and sulfuric acid and undergoing a series of post-treatment processes such as aging and acid foaming. Silica gel is an amorphous substance, and its chemical formula is mSiO2. nH2O. It is insoluble in water and any solvents, non-toxic, tasteless, chemically stable, and does not react with any substances except strong alkalis and hydrofluoric acid. Various types of silica gel form different microporous structures due to their different manufacturing methods.

    The chemical composition and physical structure of silica gel determine that it has many characteristics that other similar materials are difficult to replace: high adsorption performance, good thermal stability, stable chemical properties, and high mechanical strength. Because of its chemical properties, it is used to make many kinds of silicone products, such as silicone seals, silicone seals, silicone kitchenware and so on.

    According to the size of its pore size, silica gel is divided into: macroporous silica gel, coarse pore silica gel, type B silica gel, and fine pore silica gel. Due to the difference in pore structure, their adsorption properties have their own characteristics. Coarse-pored silica gel has a higher adsorption capacity when the relative humidity is high, while fine-pored silica gel has a higher adsorption capacity than coarse-pored silica gel when the relative humidity is low. Type B silica gel has a pore structure between coarse and fine. Between the pores, the amount of adsorption is also between the coarse and fine pores. Macroporous silica gel is generally used as a catalyst carrier, matting agent, toothpaste abrasive and so on.

    In terms of the product classification, application characteristics and precautions of silica gel, silicone rubber raw materials, and liquid silicone rubber raw materials, there will be their own differences. The application technology and main application uses of silica gel raw materials and liquid silicone rubber raw materials are familiar, and we can better To discover, research and explore more. Learn about silica gel.

    Silicone resin is mainly used as insulating paint (including varnish, enamel, colored paint, varnish, etc.) to impregnate H-class motors and transformer coils, and to impregnate glass cloth, glass cloth silk and asbestos cloth to make motor covers and electrical insulation windings Wait.

    Silicone resin can be used as heat-resistant and weather-resistant anti-corrosion coatings, metal protective coatings, waterproof and moisture-proof coatings for construction projects, release agents, adhesives and secondary processing into silicone plastics for use in electronics, electrical and defense industries. Semiconductor packaging materials and insulating materials for electronic components, etc.

    Silicone resin can also be used as heat-resistant and pressure-resistant anti-corrosion coatings, metal protective coatings, waterproof and moisture-proof coatings for construction projects, release agents, adhesives and secondary processing into silicone plastics for use in electronics, electric

    Compared with other silicone materials, silicone resins have relatively fewer varieties and a smaller market share.

    Using pure silicone resin or modified silicone resin as the base material, the silver paint with aluminum powder can be used at a temperature of 400-450°C, or even 600°C. Compared with general organic resins, silicone resins have excellent weather resistance. The wavelength range of the sunlight spectrum is more than 300nm, while silicone resins only absorb light below 280nm.


    The hydrolysis of silicone resin often includes two or more monomers with different hydrolysis rates. In order to smooth out the difference in hydrolysis rates of different silanes and cause uniform co-hydrolysis conditions, the method of simultaneous hydrolysis and alcoholysis is usually adopted.