Mold silicone rubber is composed of liquid silicone rubber and curing agent, because the liquid silicone rubber mold silicone rubber is divided into condensed industrial mold silicone rubber and additive food mold silicone rubber. The curing shapes of the two liquid silicone rubbers are quite different, so they contain different curing agent components.

Condensation type industrial grade mold silicone rubber is cured by moisture in the air. Its matching curing agent is organotin curing agent, with pungent smell. It belongs to heavy metal, non environmental friendly material and slightly toxic. When organotin curing agent and condensed industrial mold silicone rubber are in contact with each other, tin molecules and water in silicone rubber and water in air will undergo polymerization, and chains will be generated between silicone molecules, accelerating the curing of liquid silicone rubber. The addition ratio of silicone rubber curing agent for condensation industrial mold has a specified reasonable range, and the addition ratio of organotin curing agent shall not exceed 4%. If the curing agent is added less, it will produce non curing, and if it is added more, it will produce adverse conditions such as oil leakage and performance degradation of silicone rubber.

Silicone rubber liquid silicone rubber is a platinum catalyst. Platinum catalyst is an environment-friendly, non-toxic and tasteless material, which is not harmful to human body. Therefore, additive food grade silicone rubber is widely used in the production of food silicone rubber molds, which is environmentally friendly, non-toxic and harmless. Platinum catalyst is an extremely sensitive and active substance. It cannot contact with toxic substances containing heavy metals such as nitrogen, phosphorus, sulfur, lead, mercury and tin. Once contacted, it will be polluted, resulting in the decline of the performance of platinum catalyst and directly affecting the solidification of liquid silicone rubber of silicone rubber for additive food grade mold. Platinum catalyst relies on temperature to produce addition reaction with silicone rubber. The higher the temperature, the faster the silicone curing agent will be formed, and the lower the temperature, the slower the curing will be. If the temperature is below 10 ℃, it will be difficult to cure the addition liquid silicone rubber. Even after curing, the silicone rubber surface will stick.