Lead-free mirrors and environmentally safe manufacture thereof

A mirror comprising a transparent substrate, a sputtered primer layer carried on the transparent substrate, a reflective layer comprising a bright, reflective metal sputtered onto the primer layer, and a barrier layer spaced further from the transparent substrate than the reflective layer and comprising one or more metal compounds different from the metal of the reflective layer, the barrier layer being of sufficient thickness to protect the reflective layer from corrosive environments, the barrier layer including a sufficient amount of a bright, reflective metal different from the reflective metal of the reflective layer to reduce the transmittance of the combined reflective layer and barrier layer to zero percent if the transmittance of the reflective layer is greater than zero percent, and the barrier layer including an outer sputtered-on zinc-containing layer having a zinc oxide outer surface, the mirror including, over the zinc-containing layer and tightly adherent thereto, a hydrolysis and solvent-resistant, hard, cross-linked acrylic protective layer including zinc-containing pigment sufficient to improve the resistance of the mirror to sulfiding.

Method of manufacturing mirrors in a substantially pollution-free manner, comprising the steps of

• a. sputtering onto a transparent substrate a primer layer, a bright, reflective metallic layer, and a barrier layer spaced further from the transparent substrate than the reflective layer, the barrier layer including a sufficient amount of a bright, reflective metal different from the reflective metal of the reflective layer to reduce the transmittance of the combined reflective layer and barrier layer to zero percent if the transmittance of the reflective layer is greater than zero percent, the barrier layer containing a final layer having a zinc oxide outer surface,
• b. applying to the zinc oxide outer surface an aqueous coating composition comprising a heat-curable polymer system, the coating composition thoroughly wetting the zinc oxide surface, and
• c. evaporating water from the coating and curing the coating onto the zinc oxide surface to provide the latter with a hard, tenaceously adherent, protective polymeric overcoat.

Method of manufacturing mirrors in a substantially pollution-free manner, comprising the steps of

• a. sputtering onto a transparent substrate a bright, reflective metallic layer, and a barrier layer spaced further from the transparent substrate than the reflective layer, the barrier layer containing a final layer having a zinc oxide outer surface,
• b. applying to the zinc oxide outer surface an aqueous coating composition comprising a heat-curable polymer system comprising an acrylic resin and a curing agent therefor, the coating composition thoroughly wetting the zinc oxide surface and including sufficient zinc pigments to increase the resistance of the mirror to sulfiding, and
• c. evaporating water from the coating and heat-curing the coating onto the zinc oxide surface to provide the latter with a hard, tenaceously adherent, protective polymeric overcoat.