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EP-4739496-A1 - SOLAR CONTROL LAMINATED GLAZING

EP4739496A1EP 4739496 A1EP4739496 A1EP 4739496A1EP-4739496-A1

Abstract

The present invention concerns a laminated solar control glazing comprising an outer glass pane (1) and an inner glass pane (4), united by a thermoplastic intercalating sheet (3) and a solar control coating (2) applied to at least part of the inside face of the outer glass, the solar control coating (2) being such that the exterior visible light reflectance of the laminated solar control glazing RLext is at least 35% and the exterior solar energy reflectance of the laminated solar control glazing REext is at least 45%.

Inventors

  • HEVESI, KADOSA

Assignees

  • AGC Glass Europe

Dates

Publication Date
20260513
Application Date
20240701

Claims (20)

  1. Claim 1. A laminated solar control glazing comprising a. an outer glass pane (1) and an inner glass pane (4), united by a thermoplastic intercalating sheet (3) and b. a solar control coating (2) applied to at least part of the inside face of the outer glass, c. the solar control coating (2) being such that d. the exterior visible light reflectance of the laminated solar control glazing RLext is at least 35% and the exterior solar energy reflectance of the laminated solar control glazing REext is at least 45%.
  2. Claim 2. Laminated solar control glazing according to claim 1, characterized in that it has a visible light transmittance LT of at least 40% and a total solar energy transmittance g of not more than 0.450.
  3. Claim 3. Laminated solar control glazing according to claim 1, characterized in that it has a visible light transmittance LT ranging from 1% to 10% and a total solar energy transmittance g of not more than 0.130.
  4. Claim 4. Laminated solar control glazing according to any one preceding claim, characterized in that it comprises on the inner face of the second pane a low emissivity coating (5) having an emissivity less than 0.300.
  5. Claim 5. Laminated solar control glazing according to any one preceding claim, wherein the inner and/or outer glass pane (1) is heat strengthened, tempered or and/or bended.
  6. Claim 6. Laminated solar control glazing according to any one preceding claim, characterized in that RLext is at least 37%, at least 40%, or at least 41%.
  7. Claim 7. Laminated solar control glazing according to any one preceding claim, characterized in that RLext is at most 70%, at most 55%, or at most 50%.
  8. Claim 8. Laminated solar control glazing according to any one preceding claim, characterized in that REext is at least 50%, or at least 55%.
  9. Claim 9. Laminated solar control glazing according to any one preceding claim, characterized in that REext is at most 80%, at most 65%, or at most 60%.
  10. Claim 10. Laminated solar control glazing according to any one of claims 3 to 9, characterized in that TL is not more than 8%, not more than 6%, not more than 4% or not more than 3.5%.
  11. Claim 11. Laminated solar control glazing according to any one of claims 3 to 10, characterized in that TL is at least 1%, or at least 3%.
  12. Claim 12. Laminated solar control glazing according to any one of claims 3 to 11, characterized in that g is not more than 0.120, not more than 0.110, not more than 0.100, not more than 0.095, or not more 0.090.
  13. Claim 13. Laminated solar control glazing according to any one preceding claim, characterized in that the solar control coating (2) comprises an alternating arrangement of n infrared radiation reflecting functional layers and n + 1 dielectric coatings, with n > 1, such that each functional layer is surrounded by dielectric coatings.
  14. Claim 14. Laminated solar control glazing according to claim 13, characterized in that the sum of the physical thicknesses of the n functional layers is at least 25 nm, 30 nm, or 35 nm and/or at most 50 nm, 45 nm or 40 nm.
  15. Claim 15. Laminated solar control glazing according to any one of claims 13 to 14, characterized in that the solar control coating (2) comprises n=2 functional layers and comprises in sequence starting from the glass a first dielectric coating, a first functional layer, a second dielectric coating, a second functional layer and a third dielectric coating.
  16. Claim 16. Laminated solar control glazing according to claim 15, characterized in that the optical thickness of the first dielectric coating is comprised between 15 and 185 nm and/or in that the optical thickness of the second dielectric coating is comprised between 140 and 250 nm and/or in that the optical thickness of the third dielectric coating is comprised between 30 and 200 nm.
  17. Claim 17. Laminated solar control glazing according to any one of claims 15 to 16, characterized in that the sum of the optical thicknesses of the first, second and third dielectric coatings is comprised between 280 and 460 nm
  18. Claim 18. Laminated solar control glazing according to any one of claims 13 to 17, characterized in that the infrared radiation reflecting functional layers comprise silver.
  19. Claim 19. Laminated solar control glazing according to any one of claims 13 to 18, characterized in that the dielectric coatings comprise one or more layers chosen among oxides comprising SnO 2 , ZnO, Nb 2 O 5 , TiO 2 , ZrO 2 , Ta 2 O 5 or SiO 2 or among mixed oxides comprising two or more of SnO 2 , ZnO, Nb 2 O 5 , TiO 2 , Ta 2 O 5 or SiO 2 , or layers of nitrides comprising AIN, Si 3 N 4 , or SiZrN.
  20. Claim 20. Laminated solar control glazing according to any one of claims 13 to 19, characterized in that the solar control coating (2) comprises one or more layers of absorbing material having extinction coefficients k such that 1.0 < k < 3.5 considered for a wavelength of 550 nm.

Description

Description Solar control laminated glazing Technical Field [0001] The present invention relates to laminated glazing comprising a solar control coating and having a particularly low solar energy transmission. The present invention in particular relates to such a solar control laminated glazing having a high external visible light reflectance and external solar energy reflectance. [0002] The present invention also relates to such a solar control laminated glazing further comprising a low emissivity insulating coating on the innermost face of the laminated glazing. Background Art [0003] Laminated glazing is used in many ways and in many applications, mainly in motor vehicles, but also in buildings as safety glazing and has been known for a long time. Laminated glazing may also be configured as solar control glazing having low total solar energy transmittance. During the use of laminated glazing with a solar control coating, it is necessary for this coating to be protected inside the lamination, since the solar control coatings manufactured by magnetron sputtering at the present time are not resistant to bad weather or to mechanical attack. [0004] For some solar control laminated glazing a relatively high light transmittance is sought after with low total solar transmittance. However for motor vehicles having a large surface area of glass for example, the heating inside the driving compartments is reduced by using low visible light transmittance laminated glass panes which have a solar control function. The passengers' comfort is thus increased and, in addition, savings can be made in the energy costs, weight and manufacturing costs: the ventilation and air conditioning units usually used can be dimensioned so as to be of smaller power. Laminated glass panes are used in particular for side window panes, rear windows and sunroofs. In these cases, the glazing may typically be equipped with a coating which mainly reflects and/or absorbs the infrared rays. Using solar control laminated glass panes effectively prevents excessive heating of the interior of the driving compartments in a quite satisfactory manner, even when the motor vehicle has a large surface area of glass. [0005] In solar control laminated glazings of the prior art the total solar transmittance can only be lowered enough by increasing absorption. Absorption in the visible and/or infrared wavelengths may be increased be the use of colored glass and/or thermoplastic intercalating sheets that are strongly light absorbing or by using solar control coatings that are strongly light absorbing. Even then, it was found that the total solar transmittance could not be lowered below 10%. [0006] EP1765588A1 discloses for a laminated glazing for a vehicle roof various examples comprising solar control coatings on the inner side of the outer glass pane and some examples additionally bearing a low emissivity coating on the inner side of the inner glass pane. However in all those examples, the total solar energy transmittance (solar factor) remains always above 30%. [0007] W02019110172A1 a laminated glazing for a vehicle roof comprising solar control coatings on the inner side of the outer glass pane and bearing a low emissivity coating on the inner side of the inner glass pane. A total solar energy transmittance (solar factor) is obtained for low visible light transmittance and reflectance levels, meaning that light absorption is high. At high visible light absorption, a large part of solar radiation is absorbed and then re-emitted inwards, limiting thus how far the total solar transmittance level of these glazings can be lowered. Summary of invention [0008] It is an object of the present invention to provide an improved laminated glazing with solar control properties, such that the total solar transmittance (g) is significantly reduced. [0009] The laminated glazing may be provided in a window opening to separate an interior space, in particular the interior space of a vehicle or a building, from the external environment. The laminated glazing comprises a first, outer, glass pane and a second, inner, glass pane, united by a thermoplastic intercalating sheet (3). For the purpose of the present invention, the term inner glass pane (4) denotes the pane facing the interior space in the installed position and the outer pane is referred to as the pane facing the external environment in the installed position. In the context of the present invention, the surface on the inside or inside surface of a pane is understood to mean that surface of that pane which, in the installed position, faces towards the interior. In the context of the invention, the outside surface of a pane, is understood to mean that surface of the pane which in the installed position, faces towards the external environment. According to common practice in the field, the faces of the inner (4) and outer (1) glass panes are numbered from 1 to 4, as is usual in the art, starting on the outside surfa