abstract |
Organopolysiloxane compositions comprising cyclic diorganosiloxane polymers containing at least two silicon-bonded unsaturated hydrocarbon groups per molecule, organopolysiloxanes composed of the triorganosiloxy and SiO2 groups, and organohydrogenpolysiloxanes containing at least two silicon-bonded hydrogen atoms per molecule, including platinum catalysts, and fillers are disclosed. Cured products prepared from these materials are safe from cracking and possess excellent mechanical properties as well as very low moisture permeability. The compositions are suitable for various fields of applications including encapsulation of electronic parts. |