Transparent substrate provided with thin layers having reflection properties in the infrared

• US 6,306,525 B1
• Filed: 12/11/1998
• Issued: 10/23/2001
• Est. Priority Date: 12/11/1997
• Status: Expired due to Term

• Current Assignee: Saint-Gobain Vitrage
• Original Assignee: Saint-Gobain Vitrage
• Inventors: Hryniw, Bodo, Schicht, Heinz, Schmidt, Uwe, Kaiser, Wilfried
• Primary Examiner(s): Jones, Deborah
• Assistant Examiner(s): McNeil, Jennifer
• Application Number:
  US09/209,817
• Time in Patent Office: 1,047 Days
• Field of Search: 428/195, 428/201, 428/209, 428/210, 428/213, 428/325, 428/328, 428/432, 428/633, 428/433, 428/621, 428/623, 428/632, 428/336, 428/697, 428/699, 428/701, 428/702, 359/359, 359/585
• US Class Current: 428/633
• 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 17/3644 the metal being silver
• CPC Class Codes: C03C 17/3652 the coating stack containing at least one sacrificial layer to protect the metal from oxidation
• 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 2217/78 Coatings specially designed to be durable, e.g. scratch-resistant
• CPC Class Codes: Y10T 428/12535 with additional, spatially distinct nonmetal component
• CPC Class Codes: Y10T 428/12549 Adjacent to each other
• CPC Class Codes: Y10T 428/12611 Oxide-containing component
• CPC Class Codes: Y10T 428/12618 Plural oxides
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

A thin multilayer coating having reflection properties in the infrared and/or in the solar radiation range of the low-emissivity type for windows comprises a lower dielectric antireflection treatment layer, at least one silver-based functional layer, at least one metallic protection layer adjacent to the silver layer and an upper dielectric antireflection treatment layer. The upper dielectric antireflection treatment layer comprises a lower partial layer made of SnO₂, ZnO, TiO₂, Bi₂O₃ or Al₂O₃ and an upper partial layer made of a mixed oxide based on zinc and aluminium, especially one having a spinel structure of the ZnAl₂O₄ type.

Claims

1. In a transparent substrate provided with a thin multilayer coating having reflection properties in the infrared and/or in the solar radiation range of the low-emissivity type, said multilayer coating having a lower dielectric antireflection treatment layer, at least one silver-based functional layer, at least one metallic protection layer placed on and/or beneath the silver-based layer, as well as an upper antireflection treatment layer comprising a sequence of several partial layers of metal oxides, the improvement wherein the upper antireflection treatment layer comprises a lower partial layer made of SnO₂, ZnO, TiO₂, Bi₂O₃ or Al₂O₃ and an upper partial layer made of a mixed oxide based on zinc and aluminum, said mixed Zn and Al oxide layer being formed by reactive sputtering using a target based on a ZnAl alloy containing from 40 to 70% by weight of Zn and from 30 to 60% by weight of Al.

2. Substrate according to claim 1, wherein the thickness of the upper partial layer of the upper antireflection treatment layer is at least 2 to 8 nm.

3. Substrate according to claim 1, wherein the upper partial layer of the upper antireflection treatment layer is formed by the reactive sputtering using a target based on a zinc-antireflection alloy containing from 50 to 60% by weight of Zn and from 40 to 50% by weight of Al.

4. Substrate according to claim 1, wherein a surface layer based on TiO₂, ZrO₂ or Cr₂O₃ is placed on the upper partial layer of the upper antireflection treatment layer.

5. Substrate according to claim 4, wherein the surface layer has a geometrical thickness of at least 2 to 6 nm.

6. Substrate according to claim 1 wherein the mixed oxide of the upper partial layer has a spinel structure.

7. In a transparent substrate provided with a thin multilayer coating having reflection properties in the infrared and/or in the solar radiation range, of the low-emissivity type, said multilayer coating having a lower dielectric antireflection treatment layer, at least one silver-based functional layer, at least one metallic protection layer placed on and/or beneath the silver-based layer, as well as an upper antireflection treatment layer comprising a sequence of several partial layers of metal oxides, the improvement wherein the upper antireflection treatment layer comprises a lower partial layer made of SnO₂, ZnO, TiO₂, Bi₂O₃ or Al₂O₃ in direct contact with an upper partial layer made of a mixed oxide based on zinc and aluminum.

8. Substrate according to claim 7 wherein the direct contact between the upper and lower partial layers comprises an interface of a mixed oxide having a spinel structure.

9. Substrate according to claim 7, wherein the thickness of the upper partial layer of the upper antireflection treatment layer is at least 2 to 8 nm.

10. Substrate according to claim 7, wherein a surface layer based on TiO₂, ZrO₂ or Cr₂O₃ is placed on the upper partial layer of the upper antireflection treatment layer.

11. Substrate according to claim 10, wherein the surface layer has a geometrical thickness of at least 2 to 6 nm.

12. In a transparent substrate provided with a thin multilayer coating having reflection properties in the infrared and/or in the solar radiation range, of the low-emissivity type, said multilayer coating having a lower dielectric antireflection treatment layer, at least one silver-based functional layer, at least one metallic protection layer placed on and/or beneath the silver-based layer, as well as an upper antireflection treatment layer comprising a sequence of several partial layers of metal oxides, the improvement wherein the upper antireflection treatment layer comprises a lower partial layer made of SnO₂, ZnO, TiO₂, Bi₂O₃ or Al₂O₃ and an upper partial layer made of a mixed oxide based on zinc and aluminum and having a spinel structure.

13. Substrate according to claim 12, wherein the thickness of the upper partial layer of the upper antireflection treatment layer is at least 2 to 8 nm.

14. Substrate according to claim 12, wherein a surface layer based on TiO₂, ZrO₂ or Cr₂O₃ is placed on the upper partial layer of the upper antireflection treatment layer.

15. Substrate according to claim 14, wherein the surface layer has a geometrical thickness of at least 2 to 6 nm.

16. Substrate according to claim 12 wherein the mixed oxide of the upper partial layer comprises ZnAl₂O₄.