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

1. 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,

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.

2. The article comprising a substrate as claimed in claim 1 , wherein the substrate carrying the functional coating has not been subjected to heat treatment at a temperature of greater than 400° C.

3. The article comprising a substrate as claimed in claim 1 , wherein the products of the polymerization of the furfuryl alcohol represent at least 90% by weight of the weight of the temporary protective layer.

4. The article comprising a substrate as claimed in claim 1 , wherein the temporary protective layer is deposited:

over each of the main surfaces of the substrate and/or

over at least one edge of the substrate and/or

over each of the edges of the substrate.

5. The article comprising a substrate as claimed in claim 1 , wherein the temporary protective layer is directly in contact with the functional coating.

6. The article as claimed in claim 1 , wherein said substrate is made of glass, of glass-ceramic, of ceramic, of steel or of a metal having a melting point of greater than 250° C.

7. The article as claimed in claim 1 , wherein said substrate is made of glass.

8. The article comprising a substrate as claimed in claim 1 , wherein the thickness of the temporary protective layer is less than 100 micrometers.

9. 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.

10. The article comprising a substrate as claimed in claim 9 , wherein the upper layer is chosen from a layer:

of titanium nitride; of zirconium nitride; of hafnium nitride; of titanium zirconium nitride; of titanium zirconium hafnium nitride,

of titanium oxide; of zirconium oxide; of hafnium oxide; of titanium zirconium oxide; of titanium zirconium hafnium oxide.

11. 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.

12. The process for the protection of an article as claimed in claim 6 , wherein the liquid composition comprises an acid catalyst of the polymerization reaction.

13. The process for the protection of an article as claimed in claim 6 , wherein the liquid composition comprises a wetting agent or surfactant.

14. The process for the protection of an article as claimed in claim 11 , wherein the substrate is a glass substrate.

15. The process for the protection of an article as claimed in claim 11 , further comprising

removing said temporary protective layer.

16. The process for the protection of an article as claimed in claim 15 , wherein the substrate is a glass substrate.

17. The process for the protection of an article as claimed in claim 15 , wherein the temporary protective layer is removed by a heat treatment at a temperature of greater than 300° C.

18. The process for the protection of an article as claimed in claim 17 , wherein the temporary protective layer is removed by tempering, annealing and/or bending.