SILICONE COMPOSITION CATIONICALLY DUAL-CURABLE BY UV ACTIVATION AND CONDENSATION IN THE PRESENCE OF ATMOSPHERIC WATER, AND ONE METHOD FOR PREPARING SAME

摘要

Silicone compositions curable in two ways (UV exposure and ambient H2O), also known as dual cure compositions, are disclosed. One aim is to provide dual cure compositions with excellent curing properties in terms of the curing speed and rate, and without the disadvantage of being toxic. The cured materials prepared from said compositions must also have improved mechanical properties. For this purpose, among others, a silicone composition curable in at least two ways is provided that includes a polydimethylsiloxane alpha , omega -epoxydialkoxysiloxyl-type polyorganosiloxane (POS(I)) prepared by functionalising the alpha , omega -diOH precursor thereof using a functionalisation catalyst such as an alkali metal carboxylate or silanolate, with the exception of dibutylammonium formate. The composition further includes a photoinitiator (II) such as an onium borate, a condensation catalyst such as a tin salt, and optionally silicon or non-silicon additives or a filler (IV), (V), (VI), respectively. A method for preparing said POS(I), as well as a method for coating electronic substrates using said composition, particularly by conformal coating or potting, are also disclosed.