Catalytic activity and inhibition of platinum complexes for room temperature vulcanized silicone rubber

Platinum complexes of unsaturated siloxanes are useful as hydrosilation catalysts. In the process of room temperature vulcanized (RTV) silicone rubber, improved hydrosilation results are needed, however, a period of working time is also necessary in practice. Platinum at the zero oxidation state, like Karstedt catalyst is found active in parts per million levels in RTV silicon rubbers. Preferred addition cured silicone is formed by addition of an organohydrogenpolysiloxane (Si-H) across a π-bond to a vinyl-containing organopolysiloxane (C = C). The report reviews the preparation of platinum complexes from Speier's catalyst to Karstedt catalyst both of which are widely used in industry. Patents on the improvement of Karstedt catalyst and papers on the mechanism of hydrosilylation are also presented. The inhibitors for high temperature vulcanized (HTV) silicon rubber are reviewed as well as RTV silicon rubber.