COMPOSITE PANE HAVING SOLAR PROTECTION COATING AND THERMAL-RADIATION-REFLECTING COATING

Abstract

A composite pane includes an outer pane, an inner pane, and a thermoplastic intermediate layer. The composite pane has, between the outer and inner panes, a solar protection coating that substantially reflects or absorbs rays outside the visible spectrum of solar radiation. The solar protection coating includes starting from the outer pane, a layer sequence of first dielectric module (M1), first silver layer (Ag1), second dielectric module (M2), second silver layer (Ag2), third dielectric module (M3), third dielectric module (M3), third silver layer (Ag3), fourth dielectric module (M4), wherein the silver layers (Ag1, Ag2, Ag3) have a layer thickness relative to one another of Ag1/Ag2>1 and Ag1/Ag3>1, and the dielectric modules (M1, M2, M3, M4) have a relative layer thickness of M2/M1>1, M2/M3>1, and M2/M4>1.

Claims

1. A composite pane, comprising an outer pane having an exterior-side surface and an interior-side surface, an inner pane having an exterior-side surface and an interior-side surface, and a thermoplastic intermediate layer that joins the interior-side surface of the outer pane to the exterior-side surface of the inner pane, wherein the composite pane has, between the outer pane and the inner pane at least one solar protection coating, wherein the solar protection coating comprises, from a direction of the outer pane, a layer sequence of first dielectric module with a thickness M1, first silver layer with a thickness Ag1, second dielectric module with a thickness M2, second silver layer with a thickness Ag2, third dielectric module with a thickness M3, third silver layer with a thickness Ag3, fourth dielectric module with a thickness M4, wherein the first, second and third silver layers have a layer thickness relative to one another of Ag1/Ag2>1 and Ag1/Ag3>1, and the first, second, third and fourth dielectric modules have a relative layer thickness of M2/M1>1, M2/M3>1, and M2/M4>1.

2. The composite pane according to claim 1, wherein the first, second and third silver layers of the solar protection coating have a relative layer thickness of Ag1/Ag2>1 and 1<Ag1/Ag3<3.

3. The composite pane according to claim 1, wherein the second and the third silver layer of the solar protection coating have a relative layer thickness of 0.5<Ag2/Ag3<2.0.

4. The composite pane according to claim 1, wherein the first, second, third and fourth dielectric modules have a relative layer thickness M2/M1>1, M2/M3>1.1, and M2/M4>1.5.

5. The composite pane according to claim 1, wherein the first, second, third and fourth dielectric modules have at least one nitride layer.

6. The composite pane according to claim 1, wherein the layer sequence of the solar protection coating, includes at least one blocking layer.

7. The composite pane according to claim 1, wherein the solar protection coating is applied on the interior-side surface of the outer pane or on the exterior-side surface of the inner pane or wherein the solar protection coating is introduced into the thermoplastic intermediate layer.

8. The composite pane according to claim 1, wherein the thermoplastic intermediate layer contains a carrier film that has the solar protection coating.

9. The composite pane according to claim 1, wherein the composite pane has external energy reflection RE>36%.

10. The composite pane according to claim 1, wherein a visible external reflection RLext is >8%.

11. The composite pane according to claim 1, wherein a thermal-radiation-reflecting coating is applied on the interior-side surface of the inner pane.

12. The composite pane according to claim 11, wherein the thermal-radiation-reflecting layer has a functional layer based on an indium tin oxide layer (ITO) or a tin oxide layer (SnO2), with the indium tin oxide layer or the tin oxide layer arranged between two dielectric layers.

13. The composite pane according to claim 11, wherein the thermal-radiation-reflecting coating has emissivity of at most 50%.

14. A method for producing a composite pane according to claim 1, comprising: applying a solar protection coating on the interior-side surface of the outer pane, or on the exterior-side surface of the inner pane, or introducing the solar protection coating into the thermoplastic intermediate layer; and joining the outer pane and the inner pane via the thermoplastic intermediate layer.

15. The method for producing a composite pane according to claim 14, wherein a thermal-radiation-reflecting coating is applied on the interior-side surface of the inner pane.

16. A method comprising providing a locomotion vehicle for travel on land, in the air, or on water or a functional individual piece or a building with a composite pane according to claim 1.

17. The composite pane according to claim 5, wherein the at least one nitride layer is a silicon nitride layer.

18. The composite pane according to claim 6, wherein the at least one blocking layer is in contact with one of the first, second and third silver layers.

19. The composite pane according to claim 13, wherein the thermal-radiation-reflecting coating has emissivity of at most 30%.

20. The method according to claim 16, wherein the composite pane is a windshield, rear window, side window, and/or roof panel of the locomotion vehicle.

Description

[0067] The drawings are simplified schematic representations and are not to scale. The drawings in no way restrict the invention.

[0068] They depict:

[0069] FIG. 1 a cross-section through a first embodiment of the composite pane according to the invention having a solar protection layer and a thermal-radiation-reflecting layer,

[0070] FIG. 2 a cross-section through another embodiment of the composite pane according to the invention having a solar protection layer and a thermal-radiation-reflecting layer,

[0071] FIG. 3 a cross-section through another embodiment of the composite pane according to the invention having a solar protection function and a heat protection function.

[0072] FIG. 4 a schematic representation of the structure of a solar protection layer according to the invention applied on the outer pane of the composite pane;

[0073] FIG. 5 an exemplary embodiment of the method according to the invention referencing a flow chart.

[0074] FIG. 1 depicts a cross-section through an embodiment of the composite pane 100 according to the invention having a solar protection coating 4 and a low-E coating 5. The composite pane 100 comprises an outer pane 1 and an inner pane 2 joined to one another via a thermoplastic intermediate layer 3. The composite pane 100 can, for example, have a size of about 1 m.sup.2 and be provided as a roof panel of a passenger car, with the outer pane 1 facing the external environment and the inner pane 2 facing the vehicle interior. The outer pane 1 has an outer surface (I) and an inner surface (II). The inner pane 2 has an outer surface (III) and an inner surface (IV). The outer surfaces (I) and (III) face the external environment; the inner surfaces (II) and (IV) face the vehicle interior. The inner surface (II) of the outer pane 1 and the outer surface (III) of the inner pane 2 face one another.

[0075] In this embodiment, a solar protection coating 4 according to the invention is arranged on the inner surface (II) of the outer pane 1. The solar protection coating 4 extends over the entire inner surface (II), preferably minus a circumferential frame-shaped coating-free region, for example, with a width of 8 mm. The coating-free region can then be hermetically sealed by bonding to the thermoplastic intermediate layer 3. The solar protection coating 4 is thus advantageously protected against damage and corrosion.

[0076] According to the invention, the solar protection coating 4 comprises at least three functional silver layers, each of which has a layer thickness between 5 nm and 20 nm, with each functional silver layer being arranged between dielectric modules, for example, layers of silicon nitride. The silver layers (Ag1, Ag2, Ag3) of the solar protection coating according to the invention have a layer thickness relative to one another of Ag1/Ag2>1 and Ag1/Ag3>1; and the dielectric modules (M1, M2, M3, M4) have a layer thickness relative to one another of M2/M1>1, M2/M3>1, and M2/M4>1.

[0077] The solar protection coating 4 can additionally have further layers, such as sacrificial layers, barrier layers, smoothing layers, or blocking layers. Such layers can, for example, protect the solar protection coating 4 against environmental influences, for example, against oxidation, and improve its durability and environmental resistance. The structure according to the invention of the solar protection coating 4 is explained in greater detail below with respect to FIG. 4. The solar protection coating 4 results in reduced heating of the vehicle interior and of the inner pane 2 due to the reflection of infrared radiation. According to the invention, energy reflection RE>36%, preferably >39% can be achieved. Also, in addition to good improved thermal comfort compared to previously known systems, with the solar protection coating 4 according to the invention, good optical and aesthetic properties of the composite pane 100 are achieved at the same time.

[0078] A thermal protection coating 5 is optionally arranged on the inner surface (IV) of the inner pane 2. In this preferred embodiment, it is possible for the composite pane to have not only good energy reflection RE>39%, but also particularly low total transmitted thermal radiation of TTS<14%, preferably <13%. On the one hand, the thermal protection coating 5 reduces the emission of thermal radiation through the composite pane 100 into the vehicle interior, in particular at high outside temperatures. On the other hand, the thermal protection coating 5 can reduce the emission of thermal radiation out of the vehicle interior at low outside temperatures. in addition, the thermal protection coating 5 can reduce the transmittance of visible light into the vehicle interior such that no tinted pane or a less tinted pane has to be used if such reduced transmittance is desirable, for example, in the case of roof panels. These are major advantages of the composite pane according to the invention, since the interior climate of the vehicle is significantly improved and the need for the use of air conditioning systems is reduced. In terms of energy performance, in particular to achieve energy reflection RE>36 and the lowest possible TTS value of the resulting composite pane 100, it is preferred according to the invention to apply the solar protection coating 4 on a clear, non-tinted glass pane (inner side II of the outer pane 1). On the other hand, optionally, in order to neutralize, or improve, the external appearance of the composite pane 100, it can be useful for the solar protection coating 4 to be applied on a tinted glass pane (outer pane 1).

[0079] FIG. 2 depicts a cross-section through another embodiment of the composite pane 100 according to the invention having a solar protection coating and a thermal protection coating 4, 5. In contrast to FIG. 1, the solar protection coating 4 is arranged not on the inner surface (II) of the outer pane 1, but on a carrier film 6 in the intermediate layer 3. The carrier film 6 preferably contains or is made of polyethylene terephthalate (PET) and has, for example, a thickness of 50 μm. The solar protection layer 4 according to the invention comprises a layer structure, which is explained in greater detail with regard to FIG. 4. The carrier film 6 with the solar protection coating 4 is arranged between a first thermoplastic film 3a and a second thermoplastic film 3b. In the resulting composite pane, the thermoplastic films 3a and 3b and the carrier film 6 form the thermoplastic intermediate layer 3. The thermoplastic films 3a and 3b preferably contain or are made of PVB and have, for example, a layer thickness of 0.38 mm. The carrier film 6 is somewhat smaller than the outer pane 1, the inner pane 2, and the thermoplastic films 3a and 3b. The carrier film 6 is arranged in the composite such that the carrier film 6 does not extend all the way to the lateral edges of the composite glass. As a result, the carrier film 6 is surrounded in the edge region of the composite pane for example, circumferentially by the thermoplastic films 3a and 3b, with a width of approx. 8 mm. The solar protection coating 4 on the carrier film 6 is thus advantageously protected against damage and, in particular, corrosion. The thermal protection coating 5 on the inner surface (IV) of the inner pane 2 is designed as in FIG. 1.

[0080] FIG. 3 depicts a cross-section through another embodiment of the composite pane 100 according to the invention having a solar protection coating and a thermal protection coating 5, 4. In contrast to FIG. 1, the solar protection coating 4 is arranged not on the inner surface (II) of the outer pane 1, but on the outer surface (III) of the inner pane 2, with a circumferential edge region of the outer surface (III) not provided with the solar protection coating 4. In this embodiment as well, the solar protection coating 4 is advantageously protected against damage and corrosion. For the rest, this embodiment corresponds to the design depicted in FIG. 1.

[0081] FIG. 4 depicts a schematic structure of a solar protection layer 4 according to the invention. In the embodiment depicted, the solar protection coating 4 is applied on the inner side II of the outer pane 1 as a substrate. The solar protection coating 4 depicted contains three transparent functional silver layers Ag1, Ag2, and Ag3, which are, in particular, the infrared radiation-reflecting layers. According to the invention, these functional silver layers have a certain thickness relative to one another; specifically, provision is made according to the invention for the relative layer thicknesses to be Ag1/Ag2>1 and Ag1/Ag3>1. In other words, the layer thickness of the first silver layer Ag1, which is arranged closest to the outer pane 1, is thicker than the second silver layer Ag2 and the third silver layer Ag3 following below in the layer sequence. The silver layers can be deposited, for example, by cathodic sputtering in an argon atmosphere.

[0082] Dielectric layers, or dielectric modules M1, M2, M3, and M4 are in each case arranged above and below the silver layers Ag1, Ag2, and Ag3. According to the invention, these dielectric modules (M1, M2, M3, M4) have, relative to one another, a layer thickness M2/M1>1, M2/M3>1, and M2/M4>1. The dielectric module M1 is thus arranged above the first silver layer Ag1 directly on the inner side II of the outer pane 1; the second dielectric module M2 is arranged below the first silver layer Ag1. The first dielectric module M1 can, for example, be structured, starting from the outer pane 1, as a layer sequence of silicon nitride, ZnSnOx, and ZnO layers. The silicon nitride layer can be deposited from silicon nitride in a nitrogen-containing atmosphere; the zinc oxide layer, from zinc oxide in an oxygen-containing atmosphere.

[0083] The solar coating 4 contains at least one blocking layer; particularly preferably each functional silver layer Ag1, Ag2, Ag3 is situated, as depicted, in direct contact with at least one blocking layer B1, B2, and B3. According to the invention, the blocking layers preferably contain or are made of at least nickel, chromium, or alloys thereof and/or titanium chromium. The blocking layers B (B1, B2, B3) are preferably arranged between at least one functional silver layer and at least one dielectric layer. The blocking layers B protect the functional layer during heating, in particular during production of the composite pane according to the invention.

[0084] FIG. 5 depicts an exemplary embodiment of the method according to the invention referencing a flow chart comprising the following steps.

[0085] S1: Providing an outer pane 1, an inner pane 2, and at least one thermoplastic film for forming the thermoplastic intermediate layer 3;

[0086] S2: Applying a solar protection coating according to the invention on the inner surface II of the outer pane 1 or on the outer surface of the inner pane 2, for example, by means of cathodic sputtering;

[0087] S3: Optionally applying a thermal protection coating 5 on the inner side IV of the inner pane 2;

[0088] S4: Joining the outer pane 1 and the inner pane 2 via the thermoplastic intermediate layer 3 to form the composite pane 100.

[0089] In one embodiment, glass panes are used as the outer pane 1 and as the inner pane 2. In a preferred embodiment of the method, the solar protection coating 4 having the at least three functional silver layers Ag1, Ag2, and Ag3 and the at least four dielectric modules M1, M2, M3, and M4 is applied on the inner side II of the outer pane 1, preferably by means of magnetron-enhanced cathodic sputtering. Temporally, the solar protection coating 4 can be applied before, after, or simultaneously with the optional application of the thermal-radiation-reflecting coating 5 on the inner side IV of the inner pane 2. The joining of the outer pane 1 and the inner pane 2 via the intermediate layer to form the composite glass is preferably done after both the solar protection coating 4 and the optional thermal protection coating 5 have been applied.

EXAMPLES

[0090] All optical, aesthetic, and energy properties of the composite panes were measured in the laminated state or calculated for a laminated composite pane. In the Examples, the solar protection coating 4 was applied on the inner side II of a clear outer pane 1 (Example Planiclear). A tinted PVB film was used in the intermediate layer. The low-E coating was applied on the inner side IV of a dark-tinted inner pane 2 (Example VG10). The low-E coating had emissivity of 30%. The low-E coating is based on an ITO (indium tin oxide) layer encapsulated between dielectric layers (Si.sub.3N.sub.4, SiO).

[0091] Example 1 and the Comparative Example 1 were obtained by computer simulation. Examples A through E according to the invention were produced as a composite pane (roof panel for a vehicle) with the solar protection coatings indicated.

[0092] For each Example, the stack structure of the solar coating (layers and layer thicknesses) and the optical properties of the coating in the finished composite pane are indicated.

Example 1 and Comparative Example 1 (Computer Simulated in Each Case)

[0093] The layer sequences of the solar protection coatings and the layer thicknesses are presented in Table 1. The relative layer thicknesses of the silver layers and the dielectric modules, as well as the values for the optical and energy properties are reported in Table 2 and Table 3.

[0094] Abbreviations: [0095] RE energy reflection [%] [0096] RLext visible external reflection [%] [0097] TL visible light transmittance [%] [0098] TTS total transmitted thermal radiation [%] [0099] RL at 60° visible reflection at a viewing angle of 60° [%] [0100] RLint visible internal reflection [%] [0101] L*, a*, b* color coordinates (CIE color space, International Commission on Illumination)

[0102] The values for light transmittance (TL) and reflection (RL) refer to the light type A, i.e., the visible portion of sunlight at a wavelength of 380 nm to 780 nm.

TABLE-US-00001 TABLE 1 Example 1 Comp. Example 1 Layer- Layer Thickness Layer Thickness Layer Sequence Material [nm] [nm] Outer Pane 1 Glass First Dielectric Module Si3N4 21.2 10.1 M1 ZnO 7 7 Blocking Layer NiCr 0.2 0.2 First Silver Layer Ag1 Ag 17.8 11.1 Blocking Layer NiCr 0.1 0 Second Dielectric ZnO 7 7 Module M2 Si3N4 69.9 63.6 ZnO 7 7 Blocking Layer NiCr 0.1 0.6 Second Silver Layer Ag2 Ag 9. 11.8 Blocking Layer NiCr 0.2 0.7 Third Dielectric Module ZnO 7 7 M3 Si3N4 35.1 45.9 ZnO 7 7 Blocking Layer NiCr 0.1 0.4 Third Silver Layer Ag3 Ag 7.6 10.6 Blocking Layer NiCr 0.2 0.2 Fourth Dielectric Module ZnO 7 7 M4 Si3N4 15.4 12.2

TABLE-US-00002 TABLE 2 Relative Layer Thicknesses in the Solar Protection Coating Example 1 Comparative Example 1 Ag1/Ag2 1.98 0.94 Ag2/Ag3 1.18 1.11 Ag1/Ag3 2.34 1.05 M2/M1 2.98 4.55 M2/M3 1.71 1.30 M2/M4 3.75 4.05

TABLE-US-00003 TABLE 3 Energy and Optical Parameters of the Composite Pane Having the Solar Protection Coating. Example 1 Comparative Example RE 48.5 40.4 RLext 21.7 9.6 TL 4.8 4.7 TTS 12.4 14 External Color green green Color at 60° blue Rot/blue RL at 60° 23.1 13.4 RLint 2.7 2.6

Examples A Through E

[0103] The layer sequences of the solar protection coatings and the layer thicknesses of the Examples A through E are presented in Table 5. The relative layer thicknesses of the silver layers and of the dielectric modules, as well as the values for the optical and energy properties are reported in Table 6 and Table 7.

TABLE-US-00004 TABLE 5 Layer Thicknesses nm] Layer Layer Example Example Example Example Example Sequence Material A B C D E Outer Pane 1 Glass First Dielectric SiNx 8.0 10.6 9.0 16.4 7.9 Module M1 ZnSnOx 8.0 8.0 8.0 8.0 8.1 ZnO 10.0 10.0 10.0 10.0 12.3 First Silver Ag 15.8 19.0 16.5 17.8 13.3 Layer Ag1 Blocking Layer NiCr 0.2 0.2 0.2 0.2 0.2 Second ZnO 10.0 10.0 10.0 10.0 15.0 Dielectric SiNx 52.0 39.2 52.0 46.0 37.9 Module M2 ZnSnOx 8.0 8.0 8.0 8.0 9.3 ZnO 10.0 10.0 10.0 10.0 13.5 Second Silver Ag 12.3 10.6 14.3 10.8 12.1 Layer Ag2 Blocking Layer NiCr 0.2 0.2 0.2 0.2 0.8 Third Dielectric ZnO 10.0 10.0 10.0 10.0 13.0 Module MM3 SiNx 38.5 21.5 39.5 27.0 30.5 ZnSnOx 8.0 8.0 8.0 8.0 9.1 ZnO 10.0 10.0 10.0 10.0 14.2 Third Silver Ag 9.5 10.0 8.5 8.3 9.9 Layer Ag3 Blocking Layer NiCr 0.2 0.2 0.2 0.2 0.2 Fourth ZnO 10.0 10.0 10.0 10.0 16.8 Dielectric SiNx 22.5 20.0 35.6 20.3 18.7 Module M4

TABLE-US-00005 TABLE 6 Relative Layer Thicknesses of the Solar Protection Coating of the Finished Composite Panes of Examples A Through E A B C D E Ag1/Ag2 1.28 1.79 1.15 1.65 1.10 Ag2/Ag3 1.29 1.06 1.68 1.30 1.22 Ag1/Ag3 1.66 1.90 1.94 2.14 1.34 M2/M1 3.12 2.36 3.00 2.16 2.57 M2/M3 1.21 1.37 1.19 1.36 1.13 M2/M4 2.47 2.24 1.75 2.45 2.30

TABLE-US-00006 TABLE 7 Energy and Optical Parameters of the Composite Panes of Example A through E A B C D E TL 5.4 5.2 5.6 5.3 6.2 RL1 20.9 20.0 19.3 20.5 11.8 a*R 8° −0.9 −12.6 −8.5 −10.0 −5.0 b*R 8° −9.8 −4.6 −18.8 −11.1 −10.5 RL 60° 21.5 22.0 18.9 20.9 15.5 a*R 60° −3.2 −3.3 −3.2 −4.2 −3.3 b*R 60° −8.2 −6.9 −18.9 −12.4 −8.4 RE 45.6 50.7 47.6 48.5 45.3 TTS 13.7 12.2 13.2 12.9 13.8 Ext color blue green blue green blue Color @60° blue blue blue blue blue

TABLE-US-00007 TABLE 8 Relative Layer Thicknesses of the Solar Protection Coating of the Finished Composite Panes in the Comparative Example V2 Comparative Example V2 Ag1/Ag2 1.14 Ag2/Ag3 1.08 Ag1/Ag3 1.23 M2/M1 2.85 M2/M3 0.96 M2/M4 2.14

TABLE-US-00008 TABLE 9 Energy and Optical Parameters of the Composite Panes in accordance with Comparative Example V2 Comparative Example V2 TL 5.9 RLext 13.3 RL 60° 20.1 TTS 12.4 External Color yellow Color at 60° orange

[0104] According to the invention, composite panes having a solar protection coating structured according to the invention are provided which were successfully improved in terms of energy performance, thermal and visual comfort, and at the same time in terms of aesthetic appearance and were further optimized compared to known composite panes having solar protection coatings. Energy reflection of RE>36%, preferably of RE>39%, was achieved. With the solar protection coating according to the invention, composite panes can be provided in conjunction with a thermal-radiation-reflecting coating, which panes can additionally have a particularly low total transmitted thermal radiation (TTS) of less than 14%, in particular even less than 13%, while, at the same time, achieving optimum aesthetic appearance without undesirable color tones in the reflection of the composite pane. In particular, undesirable red and yellow reflections or haze of the composite pane can be avoided. According to the invention, in essence, constant, desirable color reflection of the composite pane can be achieved regardless of the viewing angle.

LIST OF REFERENCE CHARACTERS

[0105] 1 outer pane [0106] 2 inner pane [0107] 3 thermoplastic intermediate layer [0108] 3a first thermoplastic film [0109] 3b second thermoplastic film [0110] 4 solar protection coating [0111] 5 thermal protection coating [0112] 6 carrier film [0113] I outer surface of 1 [0114] II inner surface of 1 [0115] III outer surface of 2 [0116] IV inner surface of 2 [0117] Ag1 first silver layer [0118] Ag2 second silver layer [0119] Ag3 third silver layer [0120] M1 first dielectric module [0121] M2 second dielectric module [0122] M3 third dielectric module [0123] M4 fourth dielectric module [0124] B blocking layer [0125] B1 first blocking layer [0126] B2 second blocking layer [0127] B3 third blocking layer