Highly transparent silica filled organo-polysiloxane elastomers and process therefor

Abstract From the Canadian patent

Highly transparent or optically clear elastomers are prepared by mixing (1) an organopolysiloxane having a viscosity of at least 500,000 cSt at 25°c.; (2) at least 0.02 percent by weight based on the weight of the organopolysiloxane (1) of a nitrogen-containing compound having at least one triorganosilyl group in which at least one nitrogen atom is linked directly to a silicon atom or via an oxygen atom but no more than one con-, densable group is linked to a silicon atom and which is selected from the class consisting of N-triorganosilylcarbamic acid esters N-triorganosilyl-, ureas, O-triorganosilyloxyamines aminoorganosiloxanes and triorganosilyloxy- N-triorganosilylamines; (3) more than …