Transparent substrate comprising antiglare coating

• US 20060165963A1
• Filed: 07/02/2003
• Published: 07/27/2006
• Est. Priority Date: 07/03/2002
• Status: Abandoned Application

• Current Assignee: Saint-Gobain Glass France (Compagnie De Saint-Gobain)
• Original Assignee: Saint-Gobain Glass France (Compagnie De Saint-Gobain)
• Inventors: Heitz, Thibaut, Nadaud, Nicolas, Fleury, Carinne
• Application Number:
  US10/519,098
• Publication Number:
  US 20060165963A1
• Time in Patent Office: Days
• US Class Current: 428/212
• CPC Class Codes: B32B 17/10174 Coatings of a metallic or dielectric material on a constituent layer of glass or polymer
• CPC Class Codes: B32B 17/10376 Laminated safety glass or glazing containing metal wires
• 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: G02B 1/115 Multilayers
• CPC Class Codes: G02B 1/116 including electrically conducting layers
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree

Abstract

A transparent substrate (6), comprising on at least one of its faces an antireflection coating, particularly at normal incidence made of a multilayer (A) of thin layers, characterized in that the multilayer comprises, in succession:

• • a first layer (1), with a refractive index n₁ of between 1.8 and 2.2 and geometrical thickness e₁ of between 5 and 50 nm,
  • a second layer (2), with a refractive index n₂ of between 1.35 and 1.65 and a geometrical thickness e₂ of between 5 and 50 nm,
  • a third layer (3) with a refractive index n₃ of between 1.8 and 2.2 and a geometrical thickness e₃ of between 40 and 150 nm,
  • a fourth layer (4) with a refractive index n₄ of between 1.35 and 1.65 and a geometrical thickness e₄ of between 40 and 150 nm,

Claims

1. A transparent substrate (6), comprising on at least one of its faces an antireflection coating, particularly at normal incidence made of a multilayer (A) of thin layers made of dielectrical material with alternatively high and low refractive indexes, characterized in that the multilayer comprises, in succession:

a high-index first layer (1), with a refractive index n₁ of between 1.8 and 2.2 and geometrical thickness e₁ of between 5 and 50 nm,

a low-index second layer (2), with a refractive index n₂ of between 1.35 and 1.65 and a geometrical thickness e₂ of between 5 and 50 nm,

a high-index third layer (3) with a refractive index n₃ of between 1.8 and 2.2 and a geometrical thickness e₃ of between 40 and 150 nm,

a low-index depth fourth layer (4) with a refractive index n₄ of between 1.35 and 1.65 and a geometrical thickness e₄ of between 40 and 120 nm.

2. The substrate (6) as claimed in claim 1, wherein n₁ and/or n₃ are between 1.85 and 2.15, particularly between 1.90 and 2.10.

3. The substrate (6) as claimed in claim 1, wherein n₂ and/or n₄ are between 1.35 and 1.65.

4. The substrate (6) as claimed in claim 1, wherein e₁ is between 5 and 50 nm, particularly between 10 and 30 nm or between 15 and 25 nm.

5. The substrate (6) as claimed in claim 1, wherein e₂ is between 5 and 50 nm, particularly less than or equal to 35 nm or to 30 nm, particularly being between 10 and 35 nm.

6. The substrate (6) as claimed in claim 1, wherein e₃ is between 45 and 80 nm.

7. The substrate (6) as claimed in claim 1, wherein e₄ is between 45 and 110 nm and preferably between 70 and 100 nm.

8. A substrate (6) as claimed in claim 1 wherein the high-index first layer (1) and the low-index second layer (2) are replaced by an intermediate-index single layer (5) e₅ of between 1.65 and 1.80 and preferably having an optical thickness e_.pot5 of between 50 and 140 nm, preferably between 85 and 120 nm.

9. The substrate (6) as claimed in claim 8, wherein the intermediate-index layer (5) is based on a mixture of, on the one had, silicon oxide and, on the other hand, at least one metal oxide chosen from tin oxide, zinc oxide, titanium oxide or is based on a silicon oxynitiride or oxycarbide and/or aluminum oxynitride.

10. The substrate (6) as claimed in claim 1, wherein 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, zirconium oxide or based on (a) nitride(s) chosen from silicon nitride and/or aluminum nitride or based on mixed tin/zinc oxides (SnxZnyOz) or mixed zinc-titanium oxides (TiZnO_x) or based on mixed silicon-titanium oxide (SixTiyOz).

11. The substrate (6) as claimed in claim 1, wherein the high-index first layer(1) and/or the high-index third layer (3) consist of a superposition of several high-index layers, particularly of a superposition of two layers such as SnO₂/Si₃N₄ or Si₃N₄/SnO₂.

12. The substrate (6) as claimed in claim 1, wherein the low-index second layer (2) and/or the low-index fourth layer (4) are based on silicon oxide, silicon oxynitride and/or oxycarbide or on a mixed oxide of silicon and of aluminum.

13. The substrate (6) as claimed in claim 1, wherein said substrate is made of clear or bulk-tinted glass.

14. The substrate as claimed in claim 1, wherein its light reflection on the side on which it is equipped with the multilayer made up of thin layers is lowered by a minimum amount of 3 or 4% at a normal angle of incidence.

15. The substrate as claimed in claim 1, wherein the colorimetry of its light reflection on the side on which it is equipped with the multilayer made up of thin layers is such that the corresponding b* value in the (L*, a*, b*) colorimetry system is negative, at a normal angle of incidence.

16. The substrate as claimed in claim 1, wherein the antireflection multilayer uses, at least for its high-index third layer, a mixed tin/zinc or silicon titanium oxide, a silicon nitride, so that it is able to undergo a heat treatment of the curving, toughening, annealing type and so that it has enhanced mechanical and chemical durability.

17. The substrate as claimed in claim 16, wherein the antireflection multilayer uses, at least for its high-index third layer, a silicon nitiride so that it has very good mechanical durability such that Δ

H in the TABER test is less than 3%.

18. The substrate as claimed in claim 16, wherein the antireflection multilayer uses, at least for its high-index third layer, a mixed tin/zinc or silicon titanium oxide so that it is able to undergo significant heat treatment, particularly curving, bending, of great severity, it being possible for R to reach 10 cm.

19. The substrate (6) as claimed in claim 1, wherein it is equipped on one of its faces with the anti-reflection multilayer and, on its other face, either with no antireflection multilayer or also with an antireflection multilayer, or with another type of antireflection coating, or with a coating having some other functionality of the solar protection, low emissivity, antifouling, antifogging, antirain or heating type.

20. The substrate as claimed in claim 19, wherein the other type of antireflection coating is chosen from the following coatings:

a single layer with a low index, lower than 1.60 or 1.50, particularly of about 1.35-1.48, particularly based on silicon oxide,

a single layer the refractive index of which varies through its thickness, particularly of the silicon oxynitride SiO_xN_y, type, with x and y varying through its thickness,

a two-layer multilayer comprising, in succession, a layer with a high index of at least 1.8, particularly tin oxide, zinc oxide, zirconium oxide, titanium oxide, silicon or aluminum nitride, followed by a layer with a low index, below 1.65, particularly made of silicon oxide, oxynitride or oxycarbide,

three-layer multilayer comprising, in succession, a layer of medium index of between 1.65 and 1.8 of the silicon and/or aluminum oxycarbide or oxynitride type, a layer with a high index above 1.9 of the SnO₂, TiO₂ type, a layer with a low index less than 1.65 of the mixed Si—

Al oxide or silicon oxide type antifouling coating.

21. A multiple glazed unit, particularly a double glazed unit, or unit with a laminated structure, comprising at least two substrates as claimed in claim 1, wherein the two glass substrates (6, 6′

) are combined using a sheet (7) of thermoplastic, the substrate (6) being equipped, on the opposite side to the assembly, with the antireflection multilayer and the substrate (6′

) being equipped, on the opposite side to the assembly, with either no antireflection coating or also an antireflection coating, or with another type of antireflection coating, or with a coating having another functionality of the solar protection, low emissivity, antifouling, antifogging, antirain or heating type, it also being possible for said coating with another functionality to be located on one of the faces of the substrates that face toward the thermoplastic sheet used for assembly.

22. A method for obtaining producing the glazing as claimed in claim 21, comprising depositing the antireflection multilayer or multilayers is or are deposited by cathode sputtering and optionally depositing an antireflection coating by a sol-gel technique, a pyrolysis technique of the CVD, or plasma CVD type, by cathode sputtering or by corona discharge.

23. A glazed product produced by the glazing method as claimed in claim 21 wherein said glazed product is an interior or exterior glazing for buildings, a display cabinet, a counter in stores, that may be curved, an anti-dazzle computer screen, or a glass furniture.