Room temperature vulcanized silicone rubber, referred to as RTV, commonly used silicone adhesive, is a kind of silicone elastomer came out in the 1960s, without heating, can be crosslinked vulcanization at room temperature; As a new material for bonding, sealing, sealing, coating, fixation and other functions, it is widely used in aerospace, construction, industry, electronics, medical and other industries, with great use value and wide application range. Our common and commonly used RTV are: one-component condensation RTV, one-component plus molding RTV, two-component condensation RTV, two-component plus molding RTV 4. Which can be added molding vulcanized silicone rubber at higher than room temperature, such as 50-150℃ can accelerate vulcanization, so also known as low temperature vulcanized silicone rubber (LTV).

1. component condensed RTV silicone rubber
It is a mixture of polydimethylsiloxane based polymer, silica, nano calcium and other powder, supplemented by crosslinking agent, coupling agent, catalyst and so on. Sealed and stored in rubber hose before use, open contact air vulcanization to form elastomer, sealed and stored after use. Its types and application types are the most complicated compared with the other three.

2. One component plus molding RTV silicone rubber

It is a mixture of vinyl sealed poly two organosiloxane as the base glue, methyl containing hydrogen polysiloxane as the crosslinking agent, supplemented by fillers, catalysts, inhibitors and so on, packaged together. When used, the vinyl of the base glue and the silicon-hydrogen bond in the crosslinking agent will undergo silicon-hydrogen addition reaction under the platinum catalyst, and is vulcanized into a network of elastomers. Single component plus molding glue, is also packaged in a tube, packaging appearance and single component condensation type glue is similar, but its composition, vulcanization mechanism is very different. One component condensation type adhesive encapsulated in a tube, as long as it does not contact the air can keep its good storage; And single component plastic, it is under the condition of platinum catalyst vinyl and silica-hydrogen bond cross-linking reaction, without contact with the air can be vulcanized, so the storage of single component plastic plastic has become a bigger problem, in addition to the bonding of plastic is another big problem. But it can accelerate its deep vulcanization through high temperature, vulcanization rate is far more than the condensation type, greatly improve the work efficiency, widely respected.

3.Two component condensation type RTV silicone rubber

It consists of two components: the first component, that is, the base material is mainly distributed by the basic polymer and filler, and can contain cross-linking agent; The second component, vulcanizing agent, is composed of catalyst and crosslinking agent. When used, the two components are proportionally mixed and placed at room temperature to vulcanize into elastomers. In addition to having the same heat resistance, weather resistance, high and low temperature resistance and other properties as one component condensation type adhesive, it also has the following characteristics:
(1).base material and vulcanizing agent separate, good storage stability;
(2).according to the composition of the two components, the design of appropriate mixing ratio;
(3).Because the vulcanization mechanism is not entirely based on water vapor in the air, its surface and interior can be vulcanized at the same time, so the solidification rate is faster than that of single component.
(4). there are low viscosity to high viscosity liquidity, non-liquidity varieties for selection.

4.Two - component molding RTV silicone rubber

Compared with the two-component condensation type adhesive, because of its poor adhesion, it is not used for bonding and sealing function, and most of them are used as potting filler, which is the most common silicone potting adhesive in the market. This type of potting adhesive is mainly used for heat conduction potting of power supply, sensor, motor, LED drive power supply and other products, generally with a certain thermal conductivity coefficient. Is the catalyst, containing vinyl silicone polymer as one component, containing hydrogen polysiloxane as a crosslinking agent for another component, when the use of two components can be vulcanized into elastomers. It has the following characteristics:

(1). The most commonly used mixing ratio is 1:1; Heating can accelerate the vulcanization rate.
(2). silicon-hydrogen addition sulfide so no small molecule release;
(3). Catalyst and crosslinking agent are packed separately, which makes the storage life much better than that of single component plus molding glue;
(4). almost no adhesion with the base material, the need for base coating;
(5).contains silicon gel, its strength, hardness is low.