Article comprising a functional coating and a temporary protective layer made of polyfuranic resin

An article comprising a substrate comprising two main faces defining two main surfaces separated by edges, said substrate carrying:

• a functional coating deposited over at least a portion of a main surface and
• a temporary protective layer deposited over at least a portion of the functional coating,
• wherein:
• the temporary protective layer has a thickness of greater than 1 micrometer,
• the temporary protective layer comprises or consists essentially of a poly(furfuryl alcohol) resin, and
• the functional coating comprises an upper layer chosen from a metal nitride, a metal oxide or a metal oxynitride and the metal is one or more selected from the group consisting of titanium, zirconium and hafnium.

A process for the protection of an article comprising a substrate comprising two main faces defining two main surfaces separated by edges, said substrate carrying a functional coating deposited over at least a portion of a main surface, said protection process comprising the following stages:

• preparing a liquid composition comprising furfuryl alcohol,
• applying the composition to at least a portion of the functional coating over a thickness of at least 1 micrometer,
• polymerizing the composition so as to form a temporary protective layer a poly(furfuryl alcohol) resin,
• wherein the functional coating comprises a stack of thin layers successively comprising, starting from the substrate, an alternation of n functional metal layers based on silver or on silver-containing metal alloy, and (n+1) antireflective coatings, each antireflective coating comprising at least one dielectric layer, so that each functional metal layer is positioned between two antireflective coatings.