(A) study on the silicone abrasion resistant coatings for polycarbonate glazing

Abstract

Various abrasion resistant coating (ARC) solutions were formulated with colloidal silica and alkoxysilane. Aminocilane or a adhesion promoter was added in order to improve adhesion. The primer was synthesized by redical polymerization. The structure and properties of the primer were analyzed by NMR, IR, and GPC. The ARC solution containing dicyandiamide (DICY) as a base catalyst showed excellent shelf stsbilbity at room temperature, and gave good adrasion resistance after curing. The polytsiloxane/silica solutions were cured at $90^{\circ} C$ for 60 min. The resulting silicone hardcoat-polycarbonate composites were than evaluated for abrasion resistance or crosshatch adhseion failure. Mixture of 12 nm and 4 nm colloidal silica gave better abrasion resistance than single colloidal silica system. The delta % haze value was 0.51, but cross-cut test shows the failure of adhesion to polycarbonate substrate. The primed coating shwows good adhesion(100/100), but the higher value in delta% haze than that of primeless solutions.