ANTIREFLECTION-COATED TRANSPARENT SUBSTRATE EXHIBITING NEUTRAL COLOR IN REFLECTION

• US 20090104385A1
• Filed: 02/23/2007
• Published: 04/23/2009
• Est. Priority Date: 03/10/2006
• 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, Martin, Estelle
• Granted Patent: US 7,910,215 B2
• Time in Patent Office: Days
• US Class Current: 428/34
• CPC Class Codes: B32B 17/10174 Coatings of a metallic or dielectric material on a constituent layer of glass or polymer
• CPC Class Codes: C03C 17/3417 all coatings being oxide coatings
• CPC Class Codes: C03C 17/3435 comprising a nitride, oxynitride, boronitride or carbonitride
• CPC Class Codes: C03C 2217/734 comprising an alternation of high and low refractive indexes
• CPC Class Codes: G02B 1/115 Multilayers
• CPC Class Codes: Y10T 428/24975 No layer or component greater than 5 mils thick

Abstract

Transparent especially glass, substrate (6) having at least on one of its sides an antireflection coating made from a stack (A) of thin dielectric layers of alternating high and low refractive indices, characterized in that the stack comprises, in succession: a high-index first film (1) having a refractive index n₁ between 1.8 and 2.3 and a geometrical thickness e₁ of between 10 and 25 nm; a low-index second film (2) with a refractive index n₂ of between 1.40 and 1.55 and a geometrical thickness e₂ of between 20 and 50 nm; a high-index third film (3) with a refractive index n₃ of between 1.8 and 2.3 and a geometrical thickness n₃ of between 110 and 150 nm; and a low-index fourth film (4) with a refractive index n₄ of between 1.40 and 1.55 and a geometrical thickness e₄ of between 60 and 95 nm, the algebraic sum of the geometrical thickness e₃+e₁ being between 125 and 160 nm.

Claims

1. :

A transparent substrate comprising an antireflection coating made of a thin-film multilayer (A) of dielectric material with alternately high and low refractive indices, wherein the multilayer successively comprises, starting from the surface of the substrate;

a high-index first layer (1) having a refractive index n₁ of between 1.8 and 2.3 and a geometrical thickness e₁ of between 10 and 25 nm;

a low-index second layer (2) having a refractive index n₂ of between 1.40 and 1.55 and a geometrical thickness e₂ of between 20 and 50 nm;

a high-index third layer (3) having a refractive index n₃ of between 1.8 and 2.3 and a geometrical thickness e₃ of between 110 and 150 nm; and

a low-index fourth layer (4) having a refractive index n₄ of between 1.40 and 1.55 and a geometrical thickness e₄ of between 60 and 95 nm,

the algebraic sum of the geometrical thicknesses e₃+e₁ being between 125 and 160 nm, in that said multilayer (A) does not have a Zr dopant and in that said multilayer is present on at least one of the faces of said substrate, the other face being bare, covered with another coating having another functionality, for example of the solar-protection, antistatic, heating layer, anti-fogging, anti-rain or anti-soiling type, or else covered with another antireflection multilayer (A) as described previously.

2. :

The substrate as claimed in claim 1, in which n₁ and n₃ are less than 2.2.

3. :

The substrate as claimed in claim 1, in which e₁ is between 12 and 20 nm.

4. :

The substrate as claimed in claim 1, in which e₂ is between 25 and 40 nm.

5. :

The substrate as claimed in claim 1, in which e₃ is between 115 and 135 nm.

6. :

The substrate as claimed in claim 1, in which e₄ is between 75 and 95 nm.

7. :

The substrate as claimed in claim 1, in which the algebraic sum of the geometrical thicknesses e₃+e₁ is between 130 and 155 nm.

8. :

The substrate as claimed in claim 1, in which the high-index first layer (1) and/or the high-index third layer (3) are based on metal oxide(s) chosen from zinc oxide, tin oxide and zirconium oxide or based on nitride(s) chosen from silicon nitride and/or aluminum nitride or based on mixed tin/zinc oxides (Sn_xZn_yO_z), or on mixed zinc/titanium oxides (TiZnO_x), or based on mixed silicon/titanium oxides (Si_xTi_yO_z).

9. :

The substrate as claimed in claim 1, in which the high-index first layer (1) and/or the high-index third layer (3) are formed from a superposition of several high-index layers.

10. :

The substrate as claimed in claim 1, in which the low-index second layer (2) and/or the low-index fourth layer (4) are based on silicon oxide, on silicon oxynitride and/or oxycarbide or on a mixed oxide of silicon and aluminum.

11. :

The substrate as claimed in claim 1, in which said substrate is made of clear or bulk-tinted glass.

12. :

The substrate as claimed in claim 1, in which the high-index third layer is made from or comprises a mixed tin/zinc or silicon/titanium oxide.

13. :

The substrate as claimed in claim 1, in which the high-index third layer is made from or comprises a silicon nitride.

14. :

The substrate as claimed in claim 1, equipped on both of its faces with said antireflection multilayer stack.

15. :

The substrate as claimed in claim 1, equipped on one of its faces with said antireflection multilayer stack and bare on the other face or equipped on the other face with a coating having another functionality of the solar-protection, low-emissivity, anti-soiling, anti-fogging, anti-rain or heating type.

16. :

A multiple glazing unit comprising at least two substrates as claimed in claim 1, in which the two glass substrates are separated by an intermediate gas-filled space or joined together using a thermoplastic sheet, in which one of said substrates is equipped on its outer face, that is to say on the face on the opposite side from the thermoplastic sheet or from the gas-filled space, with said antireflection multilayer, and in which the other substrate, on its outer face, is bare, is coated with an antireflection multilayer of the same or different nature, or is coated with a coating having another functionality of the solar-protection, low-emissivity, anti-soiling, anti-fogging, anti-rain or heating type, and/or in which said coating having another functionality is placed on one of the faces of the substrates turned toward the thermoplastic joining sheet or toward the gas-filled space.

17. :

An interior or exterior glazing, a display cabinet, a counter, an anti-glare computer screen, or a glass furniture comprising the substrate as claimed in claim 1.

18. :

An interior or exterior glazing, a display cabinet, a counter, an anti-glare computer screen, or a glass furniture comprising the multiple glazing unit as claimed in claim 16.

19. :

The multiple glazing unit as claimed in claim 16, wherein the said glazing unit is a double glazing unit or a glazing unit with a laminated structure.

20. :

The substrate as claimed in claim 10, wherein the mixed oxide of silicon and aluminum is SiOAlF_x.

21. :

The substrate as claimed in claim 9, wherein the high-index first layer (1) and/or the high-index third layer (3) are formed from a superposition of SnO₂/Si₃N₄ or Si₃N₄/SnO₂.

22. :

The substrate as claimed in claim 4, wherein e₂ is between 30 and 40 nm.

23. :

The substrate as claimed in claim 2, wherein n₁ and n₃ are between 1.85 and 2.15.

24. :

The substrate as claimed in claim 2, wherein n₁ and n₃ are between 1.90 and 2.10.

25. :

The transparent substrate as claimed in claim 1, wherein the substrate is a glass substrate.