Classification and uses of liquid silicone

Room temperature vulcanized silicone rubber (RTV)

Room temperature vulcanized silicone rubber generally includes two categories: condensation type and addition type.

Addition-type room temperature glue is based on linear polysiloxane with vinyl groups and hydrogen-containing siloxane as the cross-linking agent. In the presence of a catalyst, a cross-linking reaction occurs at room to medium temperatures to become an elastomer. It has good heat resistance, hydrophobicity, 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. improvement. It is suitable for a variety of vulcanization methods, such as radiation vulcanization, peroxide vulcanization and addition vulcanization. It is widely used in heat resistance, moisture resistance, electrical insulation, high-strength silicone rubber products, etc.

Condensation room temperature vulcanized silicone rubber is characterized by the condensation reaction between silicone hydroxyl groups and other active substances. It can be cross-linked into elastomer silicone rubber at room temperature. The product is divided into two types: single-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 of condensation liquid silicone rubber. It is usually formulated from base polymer, cross-linking agent, catalyst, filler and additives. The product is packaged in a sealed hose and extruded during use. It can self-vulcanize into elastomer when exposed to air, making it extremely convenient to use. Vulcanized rubber 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, weather aging, and has good adhesion to a variety of metal and non-metal materials. Connectivity. It is mainly used as a coating for various electronic components and electrical equipment. The encapsulation material plays the role of insulation, moisture-proof and shock-proof; as a surface protection material for semiconductor devices; it can also be used as a sealing gap filler and elastic adhesive.

Two-component room temperature vulcanized silicone rubber (RTV-2 rubber for short) is not as convenient to use as RTV-1 rubber, but its component proportions are highly variable. One variety can produce vulcanized products with various specifications and properties, and it can also be deeply vulcanized. Therefore, it is widely used in electronic and electrical appliances, automobiles, machinery, construction, textile, chemical industry, light industry, printing and other industries for insulation, packaging, caulking, sealing, moisture-proof, earthquake resistance and roller making materials. In addition, because RTV-2 has excellent mold release properties, it is widely used as a soft mold material in the reproduction and manufacturing of cultural relics, handicrafts, toys, electronic appliances, mechanical parts, etc.

One of the typical applications of silicone sealants is glass curtain walls. The glass and aluminum alloy frames are bonded with silicone structural adhesive as exterior wall materials, and the expansion joints are waterproofed and sealed with silicone weather-resistant adhesive. Other applications include peripheral sealing of aluminum alloy doors and windows and plastic steel doors and windows, sealing of glass installation and moving troughs, rivets and fixing screws: sanitary ware and countertops, walls and furniture in kitchens, bathrooms and toilets. Waterproof sealing between aquariums, ceilings, metal roofs, showcases, counters, wall panels, and color steel plates; used for waterproof caulking sealing between high-grade highway sections, 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, etc. The demand for these varieties is relatively small, but they are indispensable on many occasions. Silicone Rubber

Among the many synthetic rubbers, silicone rubber is the best. It is odorless and non-toxic, not afraid of high temperatures and resistant to severe cold. It is "calm" and "face unchanged" at 300 degrees Celsius and minus 90 degrees Celsius, without losing its original strength and elasticity. Silicone rubber also has good electrical insulation, oxygen resistance and aging resistance, light resistance and aging resistance, mildew resistance, chemical stability, etc. Due to these excellent properties, silicone rubber has been widely used in modern medicine. In recent years, hospitals, scientific research institutions and factories have collaborated to successfully trial-produce a variety of silicone rubber medical supplies.

Silicone rubber anti-noise earplugs: comfortable to wear, can block noise well and protect eardrums.