Mold silicone rubber is generally composed of base rubber, cross-linking agent, catalyst, filler, etc.

(1) The base rubber, 107 silicone rubber, is called hydroxyl terminated polydimethylsiloxane. The mold silicone rubber can be cured at room temperature, has good fluidity, no deformation, and only slight linear shrinkage.
(2) The crosslinking agent is tetraethyl orthosilicate. The amount of crosslinking agent has obvious influence on the curing time, tear strength and elongation of silicone rubber. Practice has proved that the appropriate amount of crosslinking agent is 5% (mass fraction) of the base rubber.
(3) The catalyst is dibutyltin dilaurate. The amount of catalyst added is directly related to the curing time, which should not be too much, generally 1% - 2% (mass fraction).
(4) Fillers include talc powder, quartz powder and white carbon black. Talc powder is generally used as filler. When white carbon black is used as filler, the mechanical strength, tear strength and uniformity are significantly improved.

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