The additive liquid silicone rubber is based on polydimethylsiloxane containing vinyl, and polyorganosiloxane containing multiple Si-H bonds as the cross-linking agent. Under the action of platinum catalyst, the addition reaction is carried out at room temperature or heating to obtain the three-dimensional cross-linked structure of silicone rubber. The reaction formula is shown as follows:
In the application of two-component additive type liquid silicone rubber, when the two components are mixed, it needs a suitable operating time at room temperature. Too long time, vulcanization is too slow, is bound to reduce production efficiency; And the time is too short, the construction is tense, but also cause the waste of rubber material. For the single component additive liquid silicone rubber, it requires high stability at room temperature, can be stored for a long time . But when it rises to a certain temperature, it can be quickly vulcanized. Therefore, in order to meet the application requirements, usually need to add reaction inhibitors (such as alkynyl alcohol and vinyl siloxane, etc.). In particular, in order to achieve the transition to more convenient one-component colloids, a micro encapsulated platinum catalyst has been developed, that is, the platinum catalyst is encapsulated in a low softening point (50-200℃) resin (including organic resin and silicone resin), and the size of the capsule is less than 100μM. At room temperature or low temperature, due to the isolation of platinum, can not play a catalytic role, when the temperature rises above the softening point of resin, platinum catalyst is released, thus catalyzing addition reaction, cross linking into elastomer.