Silicone coating compositions for protecting packaged circuit boards

摘要

A room temperature curable solventless silicone coating composition includes (A) an organopolysiloxane end-blocked with a hydroxyl radical, (B) a tri- or tetra-hydrocarbonoxysilane or a partial hydrolysate thereof, and (C) a curing catalyst in the form of an organic carboxylate of a heavy metal, an organic titanate ester, a guanidyl-substituted alkoxysilane, or an organic compound having a guanidyl radical containing a siloxane. When it has a viscosity of 20 to 1000 centipoise at 25 DEG C , it is easily applicable by conventional coating techniques such as dipping and spraying, and quickly cures at room temperature into uniform coatings, suitable for covering circuit boards.