Mirror with improved durability

Patent metadata

Field	Value
Publication number	US-10746902-B2
Application number	US-201615579048-A
Country	US
Kind code	B2
Filing date	May 31, 2016
Priority date	Jun 2, 2015
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

A mirror includes a transparent substrate, at least one metallic reflecting layer and at least one protective paint layer on the back of the mirror. The mirror also includes an overlayer which is a barrier to corrosive elements, such as sulfides and/or chlorides, with a thickness of less than or equal to 6 μm which is located on the protective layer. The process for the manufacture of such a mirror is also described.

First claim

The invention claimed is:

1. A mirror comprising a transparent glass substrate, at least one metallic reflecting layer and at least one protective paint layer on the back of the mirror, wherein the mirror comprises an overlayer which is a barrier to corrosive elements with a thickness of less than or equal to 1 μm which is located on the protective layer.

2. The mirror as claimed in claim 1 , wherein the overlayer is the external layer of the mirror, located on the back of the mirror.

3. The mirror as claimed in claim 1 , wherein the overlayer is an organic resin.

4. The mirror as claimed in claim 3 , wherein the overlayer is an acrylic, vinyl, polyurethane, polyester, epoxy, alkyd or styrene resin.

5. The mirror as claimed in claim 1 , wherein the overlayer is a layer of uniform thickness.

6. The mirror as claimed in claim 1 , wherein the overlayer is a noncontinuous layer.

7. The mirror as claimed in claim 1 , wherein the protective layer is a layer of water-based or organic paint.

8. The mirror as claimed in claim 1 , wherein the thickness of the protective layer is at most 100 μm.

9. The mirror as claimed in claim 1 , wherein the metallic reflecting layer is a silver layer.

10. A process for the manufacture of a mirror, comprising:
a. an optional stage of sensitization,
b. an optional stage of activation of a surface of a transparent glass substrate to be coated,
c. a stage of deposition of at least one metallic reflecting layer on the transparent glass substrate,
d. a stage of deposition of at least one protective layer,
e. a stage of deposition of an overlayer which is a barrier to corrosive entities with a thickness of less than 1 μm, on said protective layer, to block the porosity of the latter, and
f. a stage of drying said overlayer.

11. The process as claimed in claim 10 , wherein the stage of deposition of overlayer is carried out by the liquid route by spraying, with a roller, by dip-coating, by curtain coating or by sprinkling, or by screen printing techniques.

12. The process as claimed in claim 11 , wherein the stage of deposition of the overlayer is carried out by spraying or by curtain coating and is followed by a scraping stage, so as to obtain the thinnest possible overlayer.

13. The process as claimed in claim 11 , wherein the stage of deposition of the overlayer is carried out with a roller to simultaneously carry out a scraping stage by rotation of the roller in the reverse direction, so as to obtain the thinnest possible overlayer.

14. The process as claimed in claim 10 , wherein the drying stage is carried out under hot air, by IR curing and/or by UV curing.

15. A method comprising utilizing the mirror as claimed in claim 1 as indoor mirror.

16. The mirror as claimed in claim 1 , wherein the corrosive elements include sulfides and/or chlorides.

17. The mirror as claimed in claim 8 , wherein the thickness of the protective layer is at most 50 μm.

18. The process as claimed in claim 10 , wherein the corrosive elements include sulfides and/or chlorides.

Assignees

• Saint Gobain

Inventors

• Lequippe Guillaume

Classifications

• G02B5/0808

  having a single reflecting layer (G02B5/0883, G02B5/0891 take precedence) · CPC title

• C03C17/3644

  the metal being silver · CPC title

• C03C2218/112

  by spraying · CPC title

• G02B1/14 Primary

  Protective coatings, e.g. hard coatings · CPC title

• C03C17/3663 Primary

  specially adapted for use as mirrors · CPC title