The vulcanizing agent for hot vulcanizing silicone rubber mainly includes organic peroxides, aliphatic azo compounds, inorganic compounds, high-energy rays, etc., among which the most commonly used is organic peroxides. This is because organic peroxides are generally stable at room temperature, but can decompose rapidly to produce free radicals at higher vulcanization temperatures, thus crosslinking silicone rubber.

Peroxides can be divided into two classes according to their activity. One type is universal, that is, high activity, can play a vulcanization effect on all kinds of silicone rubber; The other is vinyl special type, that is, the activity is low, can only contain vinyl silicone rubber vulcanization.

In addition to the above general distinction between the two types of peroxides, each has its own characteristics. Vulcanizing agent BP is the most commonly used vulcanizing agent for molded products. It has high vulcanizing speed and production efficiency, but it is not suitable for the production of thick products. Vulcanizing agent DCBP because of its product is not easy to volatilization, vulcanizing without pressure will also produce bubbles, especially suitable for hot air continuous vulcanization of pressed products, but its decomposition temperature is low, easy to cause coking, short storage time of glue. Vulcanizing agent BP and DCBP are crystallized powder, explosive, safe to operate and suitable for dispersion, they are usually dispersed in silicone oil or silicone rubber paste, the general content is 50%. The boiling point of vulcanizing agent is 110℃, which is very volatile. The vulcanizing agent is volatile when the rubber is stored at room temperature. It is best to use molecular sieve as a carrier. The vulcanizing agent DTBP does not react with air or carbon black and can be used to manufacture conductive rubber and products that are difficult to mold. The vulcanizing agent DBPMH is similar to DTBP, but it is not volatile at room temperature. Its decomposition products are very volatile, which can shorten the second curing time. Vulcanizing agent DCP is not volatile at room temperature, has the characteristics of vinyl special type, and the decomposition product volatility is low, can be used for external pressure small occasions vulcanization. The vulcanizing agent TBPB is used to manufacture sponge products.

The amount of peroxide is affected by many factors. For example, raw rubber variety, filler type and dosage, processing technology and so on. In general, as long as the desired cross-linking can be achieved, the curing agent should be as little as possible. However, the actual amount is much higher than the theoretical amount, because the influence of various processing factors must be taken into account, such as uneven mixing, peroxide loss in the storage of rubber materials, and the resistance of air and other compounds during vulcanization. For vinyl silicone rubber molded products with rubber, the commonly used range of peroxides by weight is as follows: curing agent BP0.5~1; Vulcanizing agent DCBP1 ~ 2; Vulcanizing agent DTBP1 ~ 2; Vulcanizing agent DCP0.5 ~ 1; Vulcanizing agent DBPMH0.5 ~ 1; Curing agent TBPB0.5~1. With the increase of vinyl content, the peroxide dosage should be reduced. The amount of peroxylate in the glue, the extruded product glue and the adhesive should be higher than that in the mould pressing glue. In some cases, the use of two kinds of peroxide can reduce the amount of curing agent, and can appropriately reduce the curing temperature, improve the curing effect.