Substrate provided with a multilayer coating having thermal properties, which includes high-refractive-index layers

• US 9,708,215 B2
• Filed: 03/08/2010
• Issued: 07/18/2017
• Est. Priority Date: 03/09/2009
• Status: Active Grant

• Current Assignee: Saint-Gobain Glass France (Compagnie De Saint-Gobain)
• Original Assignee: Saint-Gobain Glass France (Compagnie De Saint-Gobain)
• Inventors: Reymond, Vincent, Gerardin, Hadia
• Primary Examiner(s): Khatri, Prashant J
• Application Number:
  US13/254,513
• Publication Number:
  US 20120028009A1
• Time in Patent Office: 2,689 Days
• Field of Search: 428212-213, 428215-216, 428220, 428426, 428428, 428432-434, 428688-689, 428697-699, 428701-702, 428704, 359350-352, 359359-361, 359577, 359580-582, 359584-590
• CPC Class Codes: B32B 17/10229 Metallic layers sandwiched by dielectric layers
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3626 one layer at least containing a nitride, oxynitride, boronitride or carbonitride
• CPC Class Codes: C03C 17/3644 the metal being silver
• CPC Class Codes: C03C 17/366 Low-emissivity or solar control coatings
• CPC Class Codes: C03C 2217/73 Anti-reflective coatings with specific characteristics
• CPC Class Codes: G02B 5/282 reflecting for infrared and transparent for visible light, e.g. heat reflectors, laser protection
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree

Abstract

A transparent glass substrate including on a main face a thin-film multilayer coating including a metallic functional layer having reflection properties in the infrared and/or in solar radiation, for example based on silver or a metal alloy containing silver, and two antireflection films. The films each include at least two dielectric layers, the functional layer being placed between the two antireflection films. Each antireflection film includes at least one high-refractive-index dielectric layer located in contact with or close to the functional layer.

Claims

1. A transparent substrate comprising, on a main face:

a thin-film multilayer coating comprising a metallic functional layer having reflection properties in infrared and/or in solar radiation, or based on silver or a metal alloy containing silver, and two antireflection films, the antireflection films each comprising at least two dielectric layers, the functional layer being placed between the two antireflection films, the functional layer being optionally deposited directly on an underblocker film placed between the subjacent antireflection film and the functional layer and the functional layer being optionally deposited directly beneath an overblocker film placed between the functional layer and the superjacent antireflection film,

wherein each antireflection film includes at least one high-refractive-index dielectric layer located in contact with or close to the functional layer and a total optical thickness e₂ of the high-refractive-index dielectric layer or of all of the high-refractive-index dielectric layers which is or are located in the subjacent antireflection film represents between 35 and 55% of the total optical thickness e₂₀ of this subjacent antireflection film, and the total optical thickness e₆ of the high-refractive-index dielectric layer or of all of the high-refractive-index dielectric layers which is or are located in the superjacent antireflection film represents between 10 and 60% of the total optical thickness e₆₀ of this superjacent antireflection film,

wherein the physical thickness of all of the layers interposed between the high-refractive-index layer and the metallic functional layer does not exceed 10 nm and

wherein the high refractive-index layer of the superjacent antireflective film is in direct contact with a first dielectric layer, which is not a high refractive-index layer, and the first dielectric layer is in direct contact with the functional layer or the optional overblocker film that is in direct contact with the functional layer, and

wherein the high-refractive-index material of the high-refractive-index dielectric layers is predominantly in the dielectric film subjacent to the metallic functional layer such that the ratio R=e₂/e₆ of the total optical thickness e₂ of the high-refractive-index dielectric layer or of all of the high-refractive-index dielectric layers which is or are located in the subjacent antireflection film to the total optical thickness e₆ of the high-refractive-index dielectric layer or of all of the high-refractive-index dielectric layers which is or are located in the superjacent antiretlection film is between 1.4 and 1.5 including these values.

2. The substrate of claim 1, wherein the constituent material of each high-refractive-index dielectric layer is chosen from:

titanium oxide, niobium oxide, or silicon nitride doped with zirconium, or silicon nitride doped with zirconium and aluminum.

3. The substrate of claim 1, wherein the ratio E of the optical thickness e₂₀ in nm of the subjacent antireflection film to the optical thickness e₆₀ in nm of the superjacent antireflection film is such that:

0.4≦

E≦

0.9.

4. The substrate of claim 1, wherein the subjacent antireflection film and the superjacent antireflection film each include at least one dielectric layer based on silicon nitride, or based on silicon nitride doped with at least one other element or with aluminum.

5. The substrate of claim 1, wherein the final layer or overcoat of the subjacent antireflection film, that furthest away from the substrate, is an oxide-based wetting layer, or is one based on zinc oxide, or is based on zinc oxide doped with at least one other element or with aluminum.

6. The substrate of claim 1, wherein the subjacent antireflection film includes at least one nitride-based dielectric layer, or is based on silicon nitride and/or aluminum nitride, and at least one noncrystalline smoothing layer made of a mixed oxide, the smoothing layer being in contact with a crystalline superjacent wetting layer.

7. The substrate of claim 1, wherein the final layer or overcoat of the superjacent antireflection film, that furthest away from the substrate, is based on an oxide.

8. The substrate of claim 1, wherein each high-refractive-index dielectric layer is independently selected from the group consisting of titanium oxide, niobium oxide, silicon nitride doped with zirconium and silicon nitride doped with zirconium and Al.

9. The substrate of claim 1, wherein the first dielectric layer is a zinc oxide layer.

10. The substrate of claim 1, wherein the total optical thickness e₆ of the high-refractive-index dielectric layer or of all of the high-refractive-index dielectric layers which is or are located in the superjacent antireflection film represents between 15 and 35% of the total optical thickness e₆₀ of this superjacent antireflection film.

11. The substrate of claim 1, wherein the overblocker layer is present, has a physical thickness from 0.2-1.8 nm, and comprises nickel or titanium.

12. The substrate of claim 1, having a LAB a_Rc* color reflection that is positive and less than 5 and a LAB b_T* color transmission that is positive and less than 4, wherein the a_Rc* and the b_T* are measured under illuminant D₆₅ at 2°

on the opposite side of the substrate from the main face on which the thin-film multilayer coating is deposited.

13. A glazing incorporating at least one substrate of claim 1, optionally combined with at least one other substrate.

14. The glazing of claim 13, mounted as a monolithic unit, a double-glazing unit, a triple-glazing unit, or a laminated-glazing unit, wherein at least the substrate bearing the multilayer coating is bent and/or tempered.

15. The glazing of claim 13, mounted as a double-glazing unit, having a selectivity S≧

1.3.

16. A transparent electrode of a heating glazing or an electrochromic glazing comprising the glazing of claim 13.

17. A lighting device, display device or photovoltaic panel comprising the glazing of claim 13.