TRANSPARENT SUBSTRATE PROVIDED WITH A THIN-FILM MULTILAYER

• US 20140022630A1
• Filed: 03/19/2012
• Published: 01/23/2014
• Est. Priority Date: 03/24/2011
• 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, Jribi, Ramzi
• Granted Patent: US 9,494,717 B2
• Time in Patent Office: Days
• US Class Current: 359/360
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3618 Coatings of type glass/inorganic compound/other inorganic layers, at least one layer being metallic
• 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 17/3681 the multilayer coating being used in glazing, e.g. windows or windscreens
• CPC Class Codes: C03C 2217/734 comprising an alternation of high and low refractive indexes
• CPC Class Codes: G02B 5/0858 the reflecting layers comprising a single metallic layer with one or more dielectric layers

Abstract

The invention relates to a transparent substrate provided with a thin-film multilayer comprising a metallic layer having infrared-reflection properties located between two, subjacent and superjacent, nonmetallic dielectric coatings, the superjacent dielectric coating comprising the sequence of thin layers deposited in the following order:

• • at least one high-refractive-index layer, the physical thickness of the high-refractive-index layer or the sum of the physical thicknesses of the high-refractive-index layers lying between 15 and 40 nm; and
  • at least one low-refractive-index layer, the physical thickness of the low-refractive-index layer or the sum of the physical thicknesses of the low-refractive-index layers lying between 40 and 120 nm,
    the refractive index difference between the one or more high-refractive-index layers and the one or more low-refractive-index layers lying between 0.7 and 1.2, preferably between 0.8 and 1.1.

The invention allows the solar factor of a multiple glazing unit to be increased, and an acceptable color, especially in transmission, which is in particular less green, even also less yellow, to be obtained for a multiple glazing unit.

Claims

1. A transparent substrate provided with a thin-film multilayer, the thin-film multilayer comprising a metallic layer having infrared-reflection properties, and two, subjacent and superjacent, nonmetallic dielectric coatings, wherein the metallic layer having infrared-reflection properties is located between the two, subjacent and superjacent, nonmetallic dielectric coatings, and wherein the superjacent dielectric coating comprises at least the sequence of thin layers deposited, above the metallic layer having infrared-reflection properties, in the following order:

at least one high-refractive-index layer made of a material having a refractive index greater than or equal to 2.20, wherein the physical thickness of the high-refractive-index layer or the sum of the physical thicknesses of the high-refractive-index layers is from 15 to 40 nm; and

at least one low-refractive-index layer made of a material having a refractive index less than or equal to 1.70, wherein the physical thickness of the low-refractive-index layer or the sum of the physical thicknesses of the low-refractive-index layers is from 40 to 120 nm,

wherein the refractive index difference between the one or more high-refractive-index layers and the one or more low-refractive-index layers is from 0.7 to 1.2.

2. The transparent substrate of claim 1, in wherein the ratio of the physical thickness of the low-refractive-index layer or the sum of the physical thicknesses of the low-refractive-index layers to the physical thickness of the high-refractive-index layer or the sum of the physical thicknesses of the high-refractive-index layers of the superjacent dielectric coating is from 2.5 to 5.0.

3. The transparent substrate of claim 1, wherein the ratio of the total optical thickness of the superjacent dielectric coating to the total optical thickness of the subjacent coating is from 1.8 and 2.3.

4. The transparent substrate of claim 1, wherein the metallic layer having infrared-reflection properties is based on silver or a silver-containing metal alloy.

5. The transparent substrate of claim 1, wherein the metallic layer having infrared-reflection properties has a physical thickness of from 5 to 20 nm.

6. The transparent substrate of claim 1, wherein the one or more high-refractive-index layers of the superjacent dielectric coating have a refractive index greater than 2.30, and are based on titanium oxide, a mixed oxide of titanium and an element selected from the group consisting of Zn, Zr, and Sn, or based-en zirconium oxide, niobium oxide, a mixed silicon zirconium nitride, or a mixed silicon, zirconium, and aluminum nitride.

7. The transparent substrate of claim 1, wherein the physical thickness of the low-refractive-index layer of the superjacent dielectric coating or the sum of the physical thicknesses of the low-refractive-index layers of the superjacent dielectric coating is from 50 and 120 nm.

8. The transparent substrate of claim 1, wherein the one or more low-refractive-index layers of the superjacent dielectric coating consist essentially of silicon oxide.

9. The transparent substrate of claim 1, wherein the subjacent coating further comprises at least one high-refractive-index layer made of a material having a refractive index greater than or equal to 2.20, and

wherein the physical thickness of the high-refractive-index layer or the sum of the physical thicknesses of the high-refractive-index layers is from 10 to 40 nm.

10. The transparent substrate of claim 9, wherein the one or more high-refractive-index layers of the subjacent dielectric coating are based on titanium oxide, a mixed oxide of titanium and an element selected from the group consisting of Zn, Zr, and Sn, zirconium oxide, niobium oxide, a mixed silicon zirconium nitride, or a mixed silicon, zirconium, and aluminum nitride.

11. The transparent substrate of claim 1, wherein the superjacent dielectric coating further comprises a layer made of a material having a refractive index less than or equal to 2.20 and greater than or equal to 1.80 located between the metallic layer having infrared-reflection properties and the high-refractive index layer of the superjacent dielectric coating.

12. The transparent substrate of claim 11, wherein the layer made of a material having a refractive index less than or equal to 2.20 and greater than or equal to 1.80 is based on zinc oxide.

13. The transparent substrate of claim 11, further comprising:

an overblocker layer made of NiCr, Ti, or Nb, located between the metallic layer having infrared-reflection properties and the superjacent dielectric coating, and in direct contact with the metallic layer having infrared-reflection properties.

14. The transparent substrate of claim 1, wherein the subjacent dielectric coating further comprises a wetting layer based on zinc oxide, tin oxide, or a mixed tin zinc oxide, with which the metallic layer having infrared-reflection properties is in direct contact.

15. The transparent substrate claim 1, wherein the subjacent dielectric coating further comprises, as the first layer in direct contact with the substrate material, a layer having a refractive index of between 1.70 and 2.30.

16. A multiple glazing unit, comprising a total number N of substrates, N−

1 of which substrates are substrates as claimed in claim 1, wherein N is greater than or equal to 2 and the N substrates are separated pairwise by a gas-filled cavity, and the thin-film multilayer(s) facing a gas-filled cavity.

17. The multiple glazing unit of claim 16, wherein at least one of the substrates is a laminated glazing pane comprising two glass sheets joined together by an intermediate polymer layer.

18. The multiple glazing unit of claim 16, wherein its external face which is configured to be turned toward the exterior of a building, comprises a self-cleaning and/or anticondensation coating and/or its external face, which is configured to be turned toward the interior of a building, comprises a low-E coating.

19. The transparent substrate of claim 1, which is a glass substrate.

20. The transparent substrate of claim 1, wherein the ratio of the physical thickness of the low-refractive-index layer or the sum of the physical thicknesses of the low-refractive-index layers to the physical thickness of the high-refractive-index layer or the sum of the physical thicknesses of the high-refractive-index layers of the superjacent dielectric coating is from 2.5 to 4.0.