CONDENSATION SILICONES

It was the first type of silicone impression material.
Also known as conventional silicones.
Setting occurs in room temp , so called as RTV silicones.

Composition:
Base paste

Polydimethyl siloxane (hydroxy terminated)
Colloidal silica or micro sized metal oxide filler
putty viscosity – 60-70%
medium viscosity – 35-75 %
low viscosity – 5-15%
color pigments

accelerator paste

alkyl silicate (ortho ethyl silicate)
stannous octate
inert [...]