Functional glazing provided with a permanent protective film

Abstract

A glazing article, includes a substrate made of glass or made of organic substance, on the surface of which are deposited a layer or a stack of layers conferring, on the article, a functionality, in particular solar protection, thermal insulation or anticondensation properties, with a total thickness of between 5 nanometers and 400 nanometers, an organic film covering the layer or the stack of layers, the thickness of the polymer film being between 300 nanometers and 10 micrometers, wherein a texturing element is present under the layer or the stack of layers, the roughness of the surface of the texturing element being such that: the arithmetic mean deviation R.sub.a is between 50 nm and 2 micrometers, limits included, the base length R.sub.Sm is between 5 micrometers and 300 micrometers, limits included.

Claims

1. A glazing article, comprising a substrate made of glass or made of organic substance, on the surface of which are deposited: a layer or a stack of layers conferring, on said article, a functionality, with a total thickness of between 5 nanometers and 400 nanometers, said layer or stack of layers being an infrared radiation reflecting layer or an infrared radiation reflecting stack of layers, a low emissivity layer or a low emissivity stack of layers, or an anticondensation layer or an anticondensation stack of layers, an organic film covering said layer or said stack of layers, a thickness of the organic film being between 300 nanometers and 10 micrometers, wherein a texturing element is present under said layer or said stack of layers, a roughness of the surface of the texturing element being such that: an arithmetic mean deviation Ra is between 50 nm and 2 micrometers, limits included, a base length Rsm is between 5 micrometers and 300 micrometers, limits included.

2. The article as claimed in claim 1, wherein the refractive indices of the substrate and of the organic film, measured at 550 nm, are substantially identical.

3. The article as claimed in claim 1, wherein the organic film is a polymer.

4. The article as claimed in claim 1, wherein said texturing element consists of the surface of the substrate.

5. The article as claimed in claim 1, wherein said texturing element consists of a layer of an organic material positioned between the surface of the substrate and the layer or the stack of layers, the surface of said organic layer in contact with said layer or with the stack of layers, and said organic layer being textured.

6. The article as claimed in claim 1, wherein said texturing element is made of inorganic glass, of organic glass, of sol-gel material, of polymer or of sintered glass.

7. The article as claimed in claim 6, wherein said texturing element is positioned between the surface of the substrate and the layer or the stack of layers and is made of PMMA (poly(methyl methacrylate)) or of PDMS (polydimethylsiloxane).

8. The article as claimed in claim 1, wherein the organic film is chosen from a polymer selected from the group consisting of polyacrylonitrile (PAN), polymethacrylonitrile (PMAN), polycycloolefin, polyethylene (PE), polypropylene (PP), polyvinylidene chloride (PVDC), styrene-butadiene (PSB), and polysilazanes.

9. The article as claimed in claim 1, wherein the organic film is an organic sol-gel layer.

10. The glass article as claimed in claim 1, wherein the stack of layers reflects infrared radiation and comprises at least one metal layer chosen from silver, copper, gold or their alloys.

11. The glass article as claimed in claim 1, wherein the stack of layers reflects infrared radiation and comprises an upper layer that is a dielectric layer of oxide, nitride or oxynitride, on which the organic film is directly deposited.

12. The article as claimed in claim 1, wherein the substrate is made of glass.

13. The article as claimed in claim 12, wherein the texturing element is obtained by etching the surface of the glass substrate.

14. The article as claimed in claim 1, wherein the substrate is made of plastic substance chosen from the group consisting of PMMA, polycarbonate and polyethylene terephthalate (PET).

15. The article as claimed in claim 14, wherein the texturing element is obtained by application, to the surface of the substrate, of a layer of a textured material.

16. The article as claimed in claim 1, wherein a R.sub.a of the surface of said article is less than 50% of the R.sub.a of the surface of the texturing element.

17. The article as claimed in claim 1, wherein a R.sub.a of the surface of the article is less than 50 nm.

18. The article as claimed in claim 1, wherein the functionality is solar protection, thermal insulation or anticondensation properties.

19. The article as claimed in claim 5, wherein said organic material is a polymer material.

20. The article as claimed in claim 9, wherein the organic sol-gel layer is obtained by polymerization of a tetraethoxysilane (TEOS) or methyltriethoxysilane (MTEOS) Solution.

21. The article as claimed in claim 13, wherein the texturing element is obtained by a process of acid etching or basic etching or by sandblasting.

22. The article as claimed in claim 15, wherein the texturing element is obtained by embossing or by self-texturing.

23. The article as claimed in claim 1, wherein the texturing element, the layer or stack or layers and the organic film each cover entirely a same main face of the substrate.

24. The article as claimed in claim 1, wherein, at each location of the surface of the substrate where the organic film covers said layer or said stack of layers, the texturing element is present at said location under said layer or said stack of layers and between said substrate and said layer or said stack of layers to prevent formation of iridescent zones generated by optical interferences between the organic film and said layer or said stack of layers.

25. The article as claimed in claim 24, wherein at said location of the surface of the substrate where the organic film covers said layer or said stack of layers, the article has a haze value of less than 10%.

26. The article as claimed in claim 25, wherein the haze value is less than 5%.

Description

REFERENCE EXAMPLE 1

(1) A substrate made of clear glass with a thickness of 4 mm of Planilux type sold by Saint-Gobain Glass France, with a refractive index of 1.52 at 550 nm, is used.

(2) A stack of layers is deposited on the substrate, without preliminary texturing stage, by the well-known techniques of magnetic-field-assisted cathode sputtering. The stack deposited is in accordance with example 4 of the application WO2007/101964 A1 and comprises a layer of silver with a thickness of 10 nm, to which example reference will be made for further information.

(3) There is deposited, on this stack having a layer conferring an infrared-reflecting functionality on the glass article, a film of polyvinylidene chloride (PVDC with a refractive index n=1.65) of 3 micrometers, according to the liquid deposition process described below:

(4) A film of PVDC is deposited at the surface of the substrate by spin coating techniques using a polyvinylidene chloride resin Ixan® SGA-1 sold by Solvay and dissolved beforehand in ethyl acetate (solvent). The angular velocity and the concentration of the resin in the solvent are adjusted in the spinner in order to obtain a layer with a thickness of the order of 3 micrometers.

(5) A first reference glazing is thus obtained.

Example According to the Invention

(6) In this example, the protocol for producing the glazing described in the preceding reference example is taken up in an identical fashion but, in addition, an etching with acid according to the well-known techniques of the art is carried out at the surface of the glass.

(7) The etching is carried out under conditions which make it possible to obtain a texturing of the surface of the glass such that the R.sub.a value is of the order of 200 nanometers for an R.sub.Sm value of the order of 70 micrometers.

(8) The images which make it possible to measure the roughness are obtained by interferential profilometry using the Zygo Newview™ profilometer with a ×20 magnification. The data are subsequently processed by the Mountain MapMountainsMap® software, according to the methods and principles already described above.

(9) The samples according to the reference example and the example according to the invention are subsequently subjected to the following tests in order to measure their optical and energy performance qualities and also their durability.

(10) The optical and energy properties and the durability of the different glazings are measured according to the following criteria: Transmission T.sub.L: light transmission as % according to the D65 illuminant, according to the criteria defined in the international standard ISO 9050: 2003. Light reflection R.sub.L1: light transmission as % according to the D65 illuminant, layer side, according to the criteria defined in the international standard ISO 9050: 2003. normal emissivity (ε.sub.n): it is calculated according to the criteria defined in the international standard NF EN 12898: 2001. Haze: Haze, measured as percentage, is understood to mean, within the meaning of the present invention, the loss by scattering of the light, that is to say, conventionally, the ratio of the scattered part of the light (diffuse fraction or T.sub.d) to the light directly transmitted through the glazing (T.sub.L), generally expressed as percentages. The diffuse transmission thus measures the light fraction scattered by the layers deposited at the surface of the glass substrate. The haze can conventionally be measured by spectroscopy techniques, the integration over the whole visible region (380-780 nm) making it possible to determine the normal transmission T.sub.L and the diffuse transmission T.sub.d. Such a measurement can also be obtained by the use of a haze meter. It is considered that a glazing remains transparent if its haze remains less than 10% and is preferably less than 5% or even less than 1% during a measurement with a haze meter. The appliance used is a Haze-Gard® device sold by BYK-Gardner. Clarity: The clarity is also measured by virtue of the haze meter. A light ray strikes the sample and penetrates the integrating sphere of the appliance. An annular sensor fitted at the outlet orifice of the sphere detects the light scattered at the smallest angles, defined as the clarity. Sheet resistance Ω/□: the sheet resistance is measured conventionally, for example as described in the reference publication “Les techniques de l'ingénieur, Vitrage à isolation thermique renforcée [Techniques of the Engineer, Reinforced Thermal Insulation Glazing], C3635 (2004)”. SO.sub.2 test: this is a first test of durability of the stack protected by the film toward acid attacks (SO.sub.2 vapor). The test carried out is in accordance with that described in the standard EN1096-2: 2001, annex C. First, the conformity of the glazing with the standard, in particular visually, is confirmed. The variation in emissivity (Δε) and in the light transmission (ΔT.sub.L) after the test is also measured.

(11) The combined results obtained have been given in table 1 below:

(12) TABLE-US-00001 TABLE 1 Variation after SO.sub.2 test Thickness R.sub.L1 R.sub.□ (5 days) of the film L* a* b* T.sub.L Clarity Haze ε.sub.n ohms visual Units μm % % % % % % % square Δε ΔT.sub.L appearance Reference 3 57 5.2 11.6 68 99.8 0.2 26 2.93 0.9 0.2 OK Example 3 57 5.4 12.7 67 91.3 0.95 30 2.95 0.9 0.1 OK according to the invention

(13) The results given in the preceding table 1 show that the optical, colorimetric and energy performance qualities of the samples according to the reference example and the example according to the invention are substantially identical.

(14) The appended photographs (FIG. 1) show the visual appearance of the two samples: It is seen that the reference glazing (1a) exhibits an iridescence of concentric shape which is not observed on the glazing according to the invention (1b), that is to say exhibiting a surface texturing in accordance with the subject matter of the claims which follow.