SOLAR-PROTECTION GLAZED ELEMENT WITH DIFFUSE REFLECTION

Abstract

A laminated glazing structure includes first and second transparent substrates separated by a lamination interlayer, the first substrate being positioned on the outer side of the laminated glazing structure and the second substrate being arranged on the inner side of the laminated glazing structure, each transparent substrate including two main faces, the laminated glazing structure including a functional coating having solar control properties; at least one absorbing element; at least one microstructured surface, the Rdq of which is at least 0.2, at least one coating having reflective properties deposited in contact with the microstructured surface; the microstructured surface being arranged between the lamination interlayer and the second transparent substrate, the laminated glazing structure having a light transmission (LT) between 2 and 30%,

Claims

1. A laminated glazing structure comprising at least two transparent substrates separated by a lamination interlayer, a first transparent substrate of the at least two transparent substrates being positioned on an outer side of the laminated glazing structure and a second substrate of the at least two transparent substrates being arranged on an inner side of the laminated glazing structure, each transparent substrate comprising two main faces, the laminated glazing structure comprising: a functional coating having solar control properties; at least one absorbing element; at least one microstructured surface having a Rdq of at least 0.2, at least one coating having reflective properties deposited in contact with the microstructured surface; the microstructured surface being arranged between the lamination interlayer and the second transparent substrate, the laminated glazing structure having a light transmission (LT) between 2 and 30%,

2. The laminated glazing structure according to claim 1, wherein the absorbing element is arranged, relative to the microstructured surface, toward the outer side of the laminated glazing structure.

3. The laminated glazing structure according to claim 1, wherein the microstructured surface has a Rdq of less than 15.

4. The laminated glazing structure according to claim 1, wherein the absorbent element has a minimum absorption of 50%.

5. The laminated glazing structure according to claim 1, wherein the coating having reflective properties is arranged between two materials having substantially the same refractive index.

6. The laminated glazing structure according to claim 1, wherein the coating having reflective properties has a LR of greater than 5%.

7. The laminated glazing structure according to claim 1, wherein the functional coating having solar control properties is arranged between the first transparent substrate and the lamination interlayer.

8. The laminated glazing structure according to claim 1, wherein the functional coating having solar control properties is deposited in contact with the microstructured surface and also constitutes the coating having reflective properties.

9. The laminated glazing structure according to claim 1, wherein the functional coating having solar control properties comprises one or more metallic functional layers, each arranged between two dielectric coatings.

10. The laminated glazing structure according to claim 9, wherein the functional coating having solar control properties comprises two metallic functional layers.

11. The laminated glazing structure according to claim 9, wherein the one or more metallic functional layers is/are deposited directly on a dielectric coating.

12. The laminated glazing structure according to claim 1, further comprising a low-emissivity coating; directed toward the inner side of the laminated glazing structure.

13. The laminated glazing structure according to claim 12, wherein the low-emissivity coating has an emissivity of less than 36%.

14. The laminated glazing structure according to claim 13, wherein the low-emissivity coating comprises a transparent conductive layer having a thickness between 40 and 70 nm.

15. The laminated glazing structure according to claim 1, wherein the second transparent substrate is a clear glass.

16. The laminated glazing structure according to claim 1, wherein the first transparent substrate is an absorbing element.

17. The laminated glazing structure according to claim 1, wherein the lamination interlayer is an absorbing element.

18. The laminated glazing structure according to claim 1, wherein the microstructured surface is obtained by one of the following methods: acid depolishing, sandblasting, embossing, laser texturing.

19. The laminated glazing structure according to claim 1, wherein the microstructured surface consists of a textured film deposited between the lamination interlayer and the second transparent substrate.

20. The laminated glazing structure according to claim 1, wherein the laminated glazing structure has a light transmission of between 3 and 20%.

21. The laminated glazing structure according to claim 1, wherein the laminated glazing structure has a solar factor TST of between 14 and 32%.

22. The laminated glazing structure according to claim 1, wherein an internal light reflection is greater than 14%.

Description

EXAMPLES

Comparative Example 1

[0150] A glazing was made with the following elements: [0151] A first clear glass substrate 2 mm thick is intended to be positioned toward the exterior of the passenger compartment. For the solar control properties, a stack of mono Ag thin layers was deposited by magnetron on the face intended to be turned toward the inside of the structure (face 2). The stack comprises a Si.sub.3N.sub.4 dielectric layer (52 nm)/a metallic layer of Ag (12.6 nm)/a NiCr blocking layer (7.3 nm)/a Si.sub.3N.sub.4 dielectric layer (71.2 nm). [0152] A second substrate 2 mm thick, made of tinted glass, the LT of which for a thickness of 4 mm is 10%, is intended to be positioned toward the interior of the passenger compartment. This substrate is textured on its main face turned toward the inside of the structure, such that the Rdq is 4.1 The microtexturing method consists of acid etching of the glass substrate. [0153] The two substrates are laminated in a traditional manner, using an interlayer of the traditional clear PVB type (0.76 mm thick).

Comparative Example 2

[0154] The same structure as in example 1 is carried out, with the exception of the lamination interlayer which is replaced by a tinted PVB-type interlayer, the light transmission of which is 28% when it is laminated between two clear panes of glass 2 mm thick.

[0155] The thicknesses of the thin layers of the solar control coating are adapted so that the LT of the whole structure remains between 5 and 10% and that the colors remain neutral. The stack comprises: Si.sub.3N.sub.4 (12.8 nm)/Ag (9.3 nm)/NiCr (0.1 nm)/Si.sub.3N.sub.4 (50.2 nm).

Comparative Example 3

[0156] A glazing was made with the following elements: [0157] A first substrate 2 mm thick, made of tinted glass, the LT of which for a thickness of 4 mm is 10%, is intended to be positioned toward the exterior of the passenger compartment. [0158] For the solar control properties, a stack of mono Ag thin layers was deposited by magnetron on the face intended to be turned toward the inside of the structure (face 2). The stack comprises: Si.sub.3N.sub.4 (13.6 nm)/Ag (6.8 nm)/NiCr (5.9 nm)/Si.sub.3N.sub.4 (52.6 nm). [0159] The second substrate 2 mm thick is made of clear glass. This substrate is textured on its main face turned toward the inside of the structure such that the Rdq is 4.1. The microtexturing method consists of acid etching of the glass substrate. [0160] The two substrates are laminated in a traditional manner, using an interlayer of the traditional clear PVB type.

Comparative Example 4

[0161] The same structure as in comparative example 3 is created.

[0162] A stack comprising a low-E layer of ITO (indium Tin Oxide) type 55 nm thick, protected by dielectric coatings, is deposited on the face opposite the microstructured face. The emissivity of the stack is 33%.

[0163] The thicknesses of the thin layers of the solar control coating are adapted so that the LT of the whole structure remains between 5 and 10% and that the colors remain neutral.

[0164] The stack comprises: Si.sub.3N.sub.4 (21.4 nm)/Ag (5.9 nm)/NiCr (6.3 nm)/Si.sub.3N.sub.4 (42.9 nm).

[0165] Table 1 below lists the main optical characteristics of the structures obtained according to the comparative examples.

TABLE-US-00001 TABLE 1 EX. C1 Ex C2 Ex C3 Ex C4 LT (%) 8.0 7.2 10.0 10.0 Int LR (%) 6.6 4.3 13.7 13.3 Ext LR (%) 44.6 15.4 7.7 7.1 Rdq () 4.1 4.1 4.1 4.1 a* T 3.2 0.5 3.3 3.4 b* T 4.9 1.9 0.4 1.1 a*Rext 0.9 1.7 1.0 0.6 b*Rext 2.0 0.1 1.5 1.5 a*Rint 1.3 0.0 4.4 3.8 b*Rint 1.2 0.5 1.8 3.6 a*Rext 60 1.5 2.5 0.5 0.3 b*Rext 60 1.2 0.2 0.4 0.4 TST (%) 17.0 24.3 30.2 23.9

[0166] The structures created make it possible to maintain a LT between 5 and 10% and neutral colors. However, it is found that the internal LR values are less than 14%, too small to provide a screening function. In these 4 examples, there is no reflective layer on face #3 which effectively limits the achievable inner LR values.

Examples According to the Invention

Example 1

[0167] A glazing was made with the following elements: [0168] A first substrate 2 mm thick, made of tinted glass, the LT of which for a thickness of 4 mm is 10%, is intended to be positioned toward the exterior of the passenger compartment. [0169] For the solar control properties, a stack of thin layers was deposited by magnetron on face 2 (intended to be turned toward the inside of the structure) of this first substrate. The stack comprises: [0170] Si.sub.3N.sub.4 (26.2 nm)/Ag (5.3 nm)/NiCr (6.2 nm)/Si.sub.3N.sub.4 (45.5 nm). [0171] A second substrate 2 mm thick, made of clear glass, is intended to be positioned toward the interior of the passenger compartment. This substrate is textured on its main face turned toward the inside of the structure such that the Rdq is 4.1. The microtexturing method consists of acid etching of the glass substrate. [0172] A layer of titanium oxide (TiO.sub.2) 60 nm thick is deposited in a conformed manner on the microtextured surface of the second substrate. The layer has a constant thickness such that it matches the texture of the substrate. [0173] The two substrates are laminated in a traditional manner, using an interlayer of the traditional clear PVB type.

Example 2

[0174] The same structure as in example 1 according to the invention is created, with the exception of the lamination interlayer which is replaced by a tinted PVB, the light transmission of which is 28% when it is laminated between two clear panes of glass 2 mm thick.

[0175] The thicknesses of the thin layers of the solar control coating are adapted so that the stack comprises: [0176] Si.sub.3N.sub.4 (55.8 nm)/Ag (5.2 nm)/NiCr (0.1 nm)/Si.sub.3N.sub.4 (47.4 nm).

Example 3

[0177] The same structure as in example 1 according to the invention is created.

[0178] A stack comprising a low-E layer of ITO type with a thickness of 55 nm, protected by dielectric coatings, is deposited on the face opposite the microstructured face. The emissivity of the stack is 33%.

[0179] The stack of the solar control coating comprises: [0180] Si.sub.3N.sub.4 (19.7 nm)/Ag (7.1 nm)/NiCr (4.9 nm)/Si.sub.3N.sub.4 (58.0 nm).

Example 4

[0181] The same structure as in example 2 according to the invention is created.

[0182] A stack comprising a low-E layer of ITO type with a thickness of 55 nm, protected by dielectric coatings, is deposited on the face opposite the microstructured face. The emissivity of the stack is 33%.

[0183] The solar control stack comprises: [0184] Si.sub.3N.sub.4 (37.8 nm)/Ag (5.2 nm)/NiCr (0.1 nm)/Si.sub.3N.sub.4 (45.3 nm).

Example 5

[0185] A glazing was made with the following elements: [0186] For the solar control properties, a stack of mono-Ag thin layers was deposited by magnetron on the face 2 of the first substrate 2 mm thick, made of clear glass, intended to be positioned toward the exterior of the passenger compartment. The stack comprises: [0187] Si.sub.3N.sub.4 (50.2 nm)/Ag (7.4 nm)/NiCr (7.3 nm)/Si.sub.3N.sub.4 (15.1 nm). [0188] The second substrate 2 mm thick is made of clear glass. This substrate is textured on a face such that the Rdq is 4.1. The microtexturing method consists of acid etching of the glass substrate. [0189] A layer of titanium oxide (TiO.sub.2) 60 nm thick is deposited in a conformed manner on the microtextured surface of the second substrate. The layer has a constant thickness such that it matches the texture of the substrate. [0190] A stack comprising a low-E layer of ITO type with a thickness of 55 nm, protected by dielectric coatings, is deposited on the face opposite the microstructured face. The emissivity of the stack is 33%. [0191] The two substrates are laminated in a traditional manner, using a tinted PVB-type interlayer, the light transmission of which is 28% when it is laminated between two clear glasses 2 mm thick.

Example 6

[0192] The same structure as in example 5 according to the invention is carried out even with a bi-Ag solar protection coating. The stack comprises: [0193] Si.sub.3N.sub.4 (50.4 nm)/Ag (5.5 nm)/NiCr (4.8 nm)/Si.sub.3N.sub.4 (27.3 nm)/Ag (6.0 nm)/NiCr (1.4 nm)/Si.sub.3N.sub.4 (24.1 nm).

Example 7

[0194] The same structure as in example 6 according to the invention is created by replacing the layer of TiO.sub.2 with a 60 nm layer of SiZrN.

[0195] The stack comprises: Si.sub.3N.sub.4 (67.3 nm)/Ag (6.1 nm)/NiCr (3.0 nm)/Si.sub.3N.sub.4 (35.2 nm)/Ag (9.8 nm)/NiCr (0.6 nm)/Si.sub.3N.sub.4 (42.3 nm).

Example 8

[0196] A glazing was made with the following elements: [0197] The first substrate intended to be positioned toward the exterior of the passenger compartment is a tinted glass 2 mm thick, the LT of which for a thickness of 4 mm is 10%. [0198] A stack of mono-Ag thin layers has been deposited by magnetron on the microstructured surface of the second substrate 2 mm thick, made of clear glass (face 3). The stack comprises: [0199] Si.sub.3N.sub.4 (37.1 nm)/Ag (7.0 nm)/NiCr (10.2 nm)/Si.sub.3N.sub.4 (48.1 nm).

[0200] This coating fulfills both the solar control function and the reflective layer function. [0201] The two substrates are laminated in a traditional manner, using an interlayer of the clear PVB type.

Example 9

[0202] The same structure as in example 8 is carried out.

[0203] For the solar control and reflective layer properties, a bi-Ag stack was used: [0204] Si.sub.3N.sub.4 (49.1 nm)/Ag (5.5 nm)/NiCr (8.6 nm)/Si.sub.3N.sub.4 (48.4 nm)/Ag (8.9 nm)/NiCr (0.3 nm)/Si.sub.3N.sub.4 (37.6 nm).

Results

[0205] Table 2 below lists the main optical characteristics of the obtained structures according to the invention.

TABLE-US-00002 TABLE 2 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Ex. 8 Ex. 9 LT (%) 8.7 6.5 9.5 6.4 6.4 5.7 7.1 6.9 5.1 Int LR 28.3 22.0 25.0 20.1 22.0 21.6 21.8 37.6 22.9 (%) Ext LR 7.1 4.9 7.6 4.9 25 20 25 6.6 7.9 (%) Rdq () 4.1 4.1 4.1 4.1 4.1 4.1 4.1 4.1 4.1 a* T 2.7 0.0 2.6 0.2 0.7 0.4 0.2 3.7 4.3 b* T 2.1 1.9 0.3 1.6 6.0 7.8 5.4 1.9 3.7 a*Rext 0.8 0.1 1.3 0.3 3.8 4.6 0.6 0.1 0.1 b*Rext 1.5 1.4 1.6 0.7 1.7 1.3 0.7 1.2 3.3 a*Rint 0.7 3.3 2.3 4.4 3.6 3.7 3.2 2.1 4.0 b*Rint 5.7 2.9 1.5 0.7 1.2 0.0 0.1 5.0 3.3 a*Rext 0.4 0.0 0.6 0.1 3.3 4.1 1.2 0.2 0.2 60 b*Rext 0.4 0.6 0.3 0.6 3.5 4.3 1.1 0.5 1.5 60 TST 29.9 30.9 23.7 24.1 18.3 17.8 18.0 28.0 27.5 (%)

[0206] It is noted that it has been possible to maintain a LT between 4 and 10% with an internal LR of greater than 20% and neutral colors. The TST solar factor is less than 31%, or even less than 28% and for certain examples close to 18%, which gives very good solar protection in the passenger compartment.

[0207] Other variants are of course conceivable, such as tri-Ag solar control layers, other texturing methods, etc. The microtextured surface must not necessarily be carried out on one of the two substrates. It could be provided by a transparent intermediate substrate, located between the second substrate (positioned inside the glazed unit) and the lamination interlayer. In this case, a second lamination interlayer or a glue, resin or another known adhesive may be necessary to mechanically connect the intermediate substrate and the second substrate. The intermediate substrate is generally thinner than the external substrates, without however being limiting.

[0208] The transparent intermediate substrate may consist, especially, of transparent polymer, transparent glass, transparent ceramic. When the transparent substrate is made of polymer, it may be rigid or flexible. In a preferred embodiment of the invention, the intermediate substrate consists of a flexible polymer.

[0209] The texturing of one of the main surfaces of the transparent substrate may be obtained by any known method of texturing, for example by embossing the surface of the substrate heated beforehand to a temperature at which it can be deformed, in particular by rolling using a roller whose surface has texturing complementary to the texturing to be formed on the substrate; by abrasion by means of particles or abrasive surfaces, in particular by sand blasting; by chemical treatment, especially treatment with acid in the case of a glass substrate; by molding, especially injection molding in the case of a substrate of thermoplastic polymer; or by etching.

[0210] The glazed unit does not necessarily need to be transparent.

[0211] It is not necessary for the micro-textured structure to be planarized by the lamination interlayer; sol-gel resins or coatings may be used. In the case where the microtextured surface is not planarized by the lamination interlayer, the planarization of the microtextured surface can be ensured by a layer of curable material, deposited on the textured main surface of the reflective layer while being initially in a viscous state suitable for shaping operations. Such a material may be a varnish, a photocrosslinkable and/or photopolymerizable material such as a resin (such as those normally used as adhesives, glues or surface coatings) or a sol-gel material.