RTV silicone rubber generally includes condensation type and addition type.
The addition room temperature adhesive is based on linear polysiloxane with vinyl group and hydrogen containing siloxane as crosslinking agent. In the presence of catalyst, it is crosslinked at room temperature to medium temperature to become 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 the tensile strength, relative elongation and tear strength. 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 RTV silicone rubber is a silicone rubber characterized by the condensation reaction between silicone hydroxyl and other active substances, which can be crosslinked into elastomer at room temperature. The products are divided into two forms: one component packaging and two-component packaging. One component room temperature vulcanized silicone rubber (RTV-1) is one of the main products of condensed liquid silicone rubber. It is usually prepared from basic polymer, cross-linking agent, catalyst, filler and additive. The product is packed in a sealed hose, which is extruded during use, and can be vulcanized into elastomer after contacting with air. It is very convenient to use. The vulcanizate can be used for a long time in the temperature range of (– 60 ~ +200 ℃), has excellent electrical insulation performance and chemical stability, is resistant to water, ozone and climate aging, and has good adhesion to a variety of metal and non-metal materials. It is mainly used for coating various electronic components and electrical equipment, and the sealing material has the functions of insulation, moisture-proof and shockproof; As a surface protective material for semiconductor devices; It can also be used as sealing 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 proportion is rich in changes. One variety can obtain vulcanized products with various specifications and properties, and can also be deeply vulcanized. Therefore, it is widely used as insulation, packaging, caulking, sealing, moisture-proof, anti-seismic and roller making materials in the industries of electronics, automobile, machinery, construction, textile, chemical industry, light industry, printing, etc. In addition, RTV-2 has excellent demoulding property, so as a soft mold material, it is widely used in the reproduction and manufacturing of cultural relics, handicrafts, toys, electronic appliances, mechanical parts, etc.
One of the typical applications of silicone sealant is glass curtain wall. The glass and aluminum alloy frame are bonded with organic silicon structural adhesive as the exterior wall material, and the expansion joint is waterproof sealed with organic silicon weatherproof adhesive. Other applications also include the peripheral sealing of aluminum alloy doors and windows and plastic steel doors and windows, the sealing of glass installation and moving slot joints, rivets and fixed screws; the waterproof sealing between sanitary ware and countertops, walls and furniture in kitchens, bathrooms and toilets; Sealing of aquarium, ceiling, metal roof, window, counter, wall protection board and color steel plate; It is used for waterproof caulking and sealing between high-grade highway plates.
In addition to building sealant, RTV also includes sealing materials for aerospace, nuclear power station, electronics, machinery, automobile and other industries, silicone sealing materials for electronic components, silicone mold adhesive for soft mold materials, etc. The demand for these varieties is relatively small, but on many occasions it is indispensable. silicon rubber
Among the many synthetic rubbers, silicone rubber is the best among them. It is tasteless and non-toxic, not afraid of high temperature and cold resistance. At 300 degrees Celsius and minus 90 degrees Celsius, it is "calm" and "does not change its face", but still retains its original strength and elasticity. Silicone rubber also has good electrical insulation, oxygen resistance and aging resistance, light resistance and aging resistance, mold resistance, chemical stability, etc. Because of these excellent properties, silicone rubber has been widely used in modern medicine. In recent years, a variety of silicone rubber medical supplies have been successfully developed through the cooperation of hospitals, scientific research institutions and factories.
Silicone rubber anti noise earplugs: comfortable to wear, can block noise and protect eardrums.