Do You Know What the Role of Room Temperature Vulcanized Silicone Rubber is As an Adhesive?

Room temperature vulcanized silicone rubber (RTV) is a new type of silicone rubber that came out in the 1960s. Its most notable feature is that it can be cured at room temperature without heating and pressure, and it is extremely convenient to use. Therefore, as soon as room temperature vulcanized silicone rubber came out, it quickly became an important part of the entire silicone rubber product. At present, room temperature vulcanized silicone rubber has been widely used as an adhesive.

1. The role of room temperature vulcanized silicone rubber adhesive

Silicone rubber adhesive is an adhesive made of silicone rubber. Because of the low molecular weight of RTV silicone rubber, it is called liquid silicone rubber. Its physical form is usually a flowing fluid or viscous paste with a viscosity between 100 and 1000 cm. RTV silicone rubber is based on hydroxyl-terminated polysiloxane, which can be divided into one-component and two-component. One-component room temperature vulcanized silicone rubber has good adhesion to most substrates, can be used for a long time in the temperature range of -60 ≤ 200 ° C, has excellent electrical insulation and chemical stability, and has good adhesion to various metal and non-metal materials. It is mainly used to cover various electronic components and electrical equipment, including insulation, moisture-proof, shock-proof, etc. It can also be used as a sealing material and elastic adhesive.

The ratio of two-component room temperature vulcanized silicone rubber is different, and vulcanized products of various specifications can be obtained, and deep vulcanization can also be carried out. However, due to its poor bonding performance with the base material, it is mainly used for insulation, packaging, seaming, sealing, moisture-proof, roll-making and other materials in industries such as electronic appliances, automobiles, machinery, and construction. The strength of silicone rubber itself and the low bonding strength to various materials limit the application range of silicone rubber. At present, the research on the reinforcement modification of RTV silicone rubber adhesive mainly includes crosslinking agent, polysiloxane physicochemical enhancement modification and adhesive surface modification to improve its adhesive performance.

Room temperature vulcanized silicone rubber refers to silicone rubber products that can be vulcanized at room temperature without heating. Its molecular structure is characterized by active functional groups such as hydroxyl or acetoxy groups at both ends of the main chain of the molecule. Under certain conditions, these functional groups undergo condensation reactions to form a cross-linked structure and become an elastomer.

2. Room temperature vulcanized silicone rubber can be made into rubber materials with different viscosities according to the requirements of use

RTV silicone rubber has a low relative molecular weight and is usually a viscous liquid. According to its vulcanization mechanism and application process, it can be divided into one-component RTV silicone rubber and two-component RTV silicone rubber. The rubber compound of room temperature vulcanizing silicone rubber generally has fluid grade, medium consistency grade and consistency grade. Fluid-grade rubber is fluid, suitable for pouring and spray gun operation; if lower viscosity rubber is required, methyltriethoxysilane or its oligomers can be infiltrated into the rubber, and methyl silicone oil can also be used for dilution. The viscosity of the medium-consistency glue is just enough to flow fully without flowing down completely, and a product with a smooth surface can be obtained, which is suitable for gluing and dipping. The consistency grade has a putty-like consistency and can be operated by hand, scraper or caulking knife, and can also be applied to various fabrics by calendering.