| abstract |
It is difficult to provide abrasion resistance coatings with both good coatability, optical clarity and the ability to be tinted after application of the coating to a transparent substrate, such as an ophthalmic lens. An abrasion-resistant coating that adheres well to the substrate and is clear, transparent, colorless, and free of visible specks comprises a solvent, an epoxy resin composition, an aminosilane, and an hydrocarbyltrihydrocarboxysilane, such as an alkyltrialkoxysilane. The aminosilane may be a partially hydrolyzed aminosilane that is effectively blocked from reacting with the epoxy resin composition at ambient temperature. The coating composition is applied to the substrate and then treated to remove any block from the hydrolyzable aminosilane such that the aminosilane and the epoxy resin composition react to form an abrasion-resistant coating. The coating is also controllably tintable and is strongly adherent to the substrate even after tinting or exposure to heat and humidity. |