RTV (room temperature vulcanized silicone rubber) is a new type of silicone elastomer that came out in the 1960s. The most significant characteristic of this rubber is that it can be cured at room temperature without heating and pressure, and it is extremely convenient to use. Therefore, as soon as it comes out, it becomes an important part of the whole silicone product. Now RTV silicone rubber has been widely used as adhesives, sealants, protective coatings, sealing and molding materials, in all walks of life have its use. RTV silicone rubber is known as liquid silicone rubber due to its low molecular weight. Its physical form is usually fluid or sticky paste, with viscosity between 100 and 1000000 centistokes. According to the requirements of use, can be vulcanized before the rubber material into automatic leveling of perfusion material or do not flow but can be coated with scraping putty. The packing of RTV silicone rubber is similar to that of high temperature silicone rubber, which is reinforced with white carbon black, so that the vulcanized rubber has 10 ~ 60 kg/cm 2 breaking strength. Filling different additives can make the rubber material has different specific gravity, hardness, strength, fluidity and thixotropy, and make the vulcanized rubber has a flame retardant, electric conductivity, heat conduction, ablative resistance and other special properties.

RTV silicone rubber can be divided into single component and double component RTV silicone rubber according to its packaging mode, and can be divided into condensation type and molding according to the vulcanization mechanism. Therefore, RTV silicone rubber can be divided into three types according to the composition, vulcanization mechanism and different use process, that is, single-component RTV silicone rubber, two-component condensation RTV silicone rubber and two-component molding RTV silicone rubber.

The raw rubber of single component and two component condensation RTV silicone rubber is α,ω -dihydroxy polysiloxane; Add molding room temperature vulcanized silicone rubber is containing alene and hydrogen side group (or end group) polysiloxane, because in the curing, often slightly higher than room temperature (50 ~ 150℃) can achieve good curing effect, so, also known as low temperature vulcanized silicone rubber (LTV).
These three series of RTV silicone rubber have their own advantages and disadvantages: the advantage of single component RTV silicone rubber is convenient to use, but the deep curing speed is difficult; The advantages of two-component RTV silicone rubber are that curing is not exothermic, shrinkage is very small, no expansion, no internal stress, curing can be carried out inside and on the surface at the same time, can be deep curing; The curing time of RTV silicone rubber is mainly determined by temperature, so the curing speed can be controlled by adjusting temperature.