Multipurpose glazing varnish based on shellac and synthetic resin

摘要

Metal objects/artifacts made of brass, copper, aluminium etc. tarnish on exposure to atmosphere. These require periodic cleaning of the oxidative coating by rubbing/polishing formulations. Similarly, other materials like, plastic, rexin, painted artworks, murals, rubber etc. become dull and unattractive with the passage of time. Restorers/commercially available grinding/ polishing formulations do not provide long lasting protection from tarnishing of metal objects; also require periodic cleaning by rubbing/polishing. Consumers prefer use of a coating, which is more permanent in nature and avoids frequent application of restorer. A varnish formulation based on shellac and synthetic resin, has been developed; application of double coat (or more, if required) provides sheen on the surface, which remains unaffected for 2-3 years i.e., it eliminates frequent rubbing/polishing of the artifacts. The films of the varnish maintain glossy appearance for a period much longer than that of varnish from shellac alone or compared to commercial rubbing/polishing formulations even after exposure to environmental stress.