| abstract |
Polyorganosiloxanes having an average of more than two siloxane repeat units, at least one of which repeat units includes a photoinitiating group bound to the silicon atom thereof, the photoinitiating group having the formula ##STR1## where R 1 and R 2 are the same or different alkyl groups or R 1 and R 2 are alkylene groups linked to each other so that R 1 and R 2 together with the carbon atom to which both are attached comprise a cycloalkyl group, and R 3 is H or hydrocarbyl. n Compositions of these polyorganosiloxanes and silicones or organic monomers with free radical curable groups are readily cured by irradiation with UV light. |