Room temperature vulcanized silicone rubber (RTV) is a new type of silicone elastomer, which was developed in 1960s. The most remarkable feature of RTV is that it can be cured in situ without heating and pressure at room temperature, and it is very convenient to use. Therefore, as soon as it comes out, it becomes an important part of the whole silicone product. At present, RTV silicone rubber has been widely used as adhesives, sealants, protective coatings, potting and molding materials, and has its applications in all walks of life. Room temperature vulcanized silicone rubber is known as liquid silicone rubber because of its low molecular weight. Its physical form is usually fluid or viscous paste, and its viscosity is between 100-1000000 centistokes. According to the requirements of use, the compound before vulcanization can be prepared into automatic leveling filling material or non flowing but scraped putty. The filler used in RTV silicone rubber is similar to HTV silicone rubber, which is reinforced by silica, so that the vulcanizate has a tensile strength of 10-60 kg / cm2. Adding different additives can make the compound have different specific gravity, hardness, strength, fluidity and thixotropy, and make the vulcanizate have various special properties such as flame retardant, conductivity, heat conduction and ablation resistance.








Room temperature vulcanized silicone rubber can be divided into single-component and two-component room temperature vulcanized silicone rubber according to its packaging method, and can be divided into condensation type and addition type according to the vulcanization mechanism. Therefore, RTV silicone rubber can be divided into three types according to its composition, curing mechanism and application process, i.e. one-component RTV silicone rubber, two-component condensation RTV silicone rubber and two-component addition RTV silicone rubber.








The raw rubber of one component and two-component condensation room temperature vulcanized silicone rubber is α, ω - dihydroxypolysiloxane; the addition room temperature vulcanized silicone rubber is polysiloxane containing alkenyl and hydrogen side group (or end group), because it can achieve good curing effect when it is slightly higher than room temperature (50-150 ℃), so it is also called low temperature vulcanized silicone rubber (LTV).








The three series of RTV silicone rubber have their own advantages and disadvantages: one component RTV silicone rubber has the advantages of convenient use, but the deep curing speed is difficult; two component RTV silicone rubber has the advantages of no exothermic during curing, Shrinkage is very small, no expansion, no internal stress, curing can be carried out at the same time inside and on the surface, and deep curing can be carried out; the curing time of addition molding RTV silicone rubber mainly depends on the temperature, so the curing speed can be controlled by adjusting the temperature.