Solvent-free moisture curing silicone conformal coating and preparation method thereof

Abstract

The present disclosure relates to a solvent-free moisture curing silicone conformal coating used for the surface protection of circuit boards in the electrical and electronic industries and a preparation method thereof. The solvent-free moisture curing silicone conformal coating comprises (A) a hydrolyzable functional group-terminated linear polysiloxane (I); (B) a hydrolyzable functional group-containing silicone resin with a three-dimensional structure (II); (C) a hydrolyzable functional group-containing crosslinking agent; (D) a catalyst; (E) an adhesion promoter. The solvent-free conformal coating of the present disclosure has low viscosity, high strength and good toughness, and can meet the traditional coating process such as spraying, brushing, dipping, etc., while satisfying the surface protection of the circuit board. Compared with the traditional solvent-based silicon conformal coating, the solvent-free silicon conformal coating can be cured by moisture, the VOC content released during the curing process is low, and the harm to the environment and occupational health is small.