Electrically heated glazing, method for producing electrically heated glazing, and use of electrically heated glazing

Abstract

The invention relates to an electrically heated glazing (10) comprising a first glass sheet (1), a first masking layer (2) around the outer edge of the first glass sheet (1), an aperture (3) for a sensor in the first masking layer (2), a second glass sheet (4) bonded to the first glass sheet (1) by a ply of interlayer material (5), a carrier film (6) positioned between the ply of interlayer material (5) and the first glass sheet (1), an electric heating element (7) on the carrier film (6), and a second masking layer (8) on the carrier film (6). The second masking layer positioned on the carrier film reduces optical distortions by reducing stresses in the glass sheet during forming. The invention also relates to a method for producing the glazing and to the use of the glazing, for example as a vehicle window.

Description

[Technical field]

[0001] The present invention is an electrically heated glazing, a method for producing an electrically heated glazing, and the use of an electrically heated glazing, for example as a window in a vehicle. [Background technology]

[0002] Electrically heated glazing is well known, comprising a glass sheet, a masking layer on the glass sheet, and an aperture for a sensor in the masking layer. Typically, an electric heating element is provided for defogging or defrosting, and a sensor is able to transmit and receive data through the aperture.

[0003] Patent Document 1 (EP3118036A1 (Sakamoto)) discloses a windshield including a glass sheet utilizing a mask layer. The amount of thermally induced expansion of the mask layer during the forming process is different from the amount of expansion of the glass sheet. As a result, distortion of the image seen through the glass sheet occurs near the boundary between the mask layer and the opening. The information acquisition device is configured in the opening to reduce the effect of distortion occurring within a predetermined range from the edge of the opening, or to make the passing range of light irradiated or received by the information acquisition device pass near the center of the opening.

[0004] US2017297310A1 (Mannheim Astete) describes a black band on glass that protects the polyurethane adhesive by blocking ultraviolet light. During the bending process, the black band absorbs more radiant heat than the glass. Due to a temperature gradient of several tens of degrees Celsius rising over a short distance, optical distortions known as "burn" lines occur along the inner edge of the black band. The solution to the problem of burn line distortion is to print an obscuration directly on the surface of a plastic film that is laminated between at least two sheets of a thermoplastic interlayer. The plastic film, made of polyethylene terephthalate (PET) and on which the obscuration is printed, has a lower distortion measured in diopters and an improved modulation transfer function (MTF). Heating elements are not disclosed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] European Patent Application Publication No. 3118036 [Patent Document 2] US Patent Application Publication No. 2017 / 297310 Summary of the Invention [Problem to be solved by the invention]

[0006] There remains a need for alternative electrically heated glazing.

[0007] Object of the Invention It is an object of the present invention to provide a glazing for electric heating with a predetermined amount of distortion. Another object is to provide a simple method for producing a glazing for electric heating with a predetermined amount of distortion.

[0008] (Summary of the Invention) In a first aspect, the present invention provides a glazing for electric heating having the features as claimed in claim 1.

[0009] The present invention provides an electrically heated glazing comprising a first glass sheet, a first masking layer around an outer edge of the first glass sheet, an aperture for a sensor in the first masking layer, a second glass sheet joined to the first glass sheet by a ply of interlayer material, a carrier film positioned between the ply of interlayer material and the first glass sheet, an electric heating element disposed on the carrier film, and a second masking layer positioned on the carrier film.

[0010] The present invention is highly advantageous because glazing having a second masking layer disposed on a carrier film allows for lower stresses and less distortion of the glass sheet during forming.

[0011] Surprisingly, the inventors have found that a second masking layer disposed on the carrier film and defining the edges of the aperture for the sensor allows the aperture in the first masking layer to be larger, so that distortions caused by the first masking layer do not occur in the field of view of the sensor.

[0012] Additionally, the second masking layer disposed on the carrier film allows the second masking layer to move relative to the first glass sheet during the manufacturing process of the glazing, so that it does not distort due to different thermal expansion coefficients of the second masking layer and the first glass sheet.

[0013] An advantage of the present invention is that the glazing meets the requirements of industrial testing, for example, distortion, defogging and defrosting of vehicle windows.

[0014] Preferably, the second masking layer is on the surface of the carrier film opposite the electric heating element side.

[0015] Preferably, the electric heating element is in contact with the first glass sheet.

[0016] Preferably, the second masking layer has an inner edge whose shape is selected from a straight line, an arcuate shape, an ellipse, a circle, a triangle, a square shape, a rectangle, a parallelogram, or a trapezoid, each shape may be open or closed.

[0017] Preferably, the second masking layer has an outer edge and a width between the outer edge and the inner edge, the width being from 1 to 100 mm, more preferably from 3 to 30 mm, and most preferably from 5 to 25 mm.

[0018] Preferably, the inner edge of the second masking layer is spaced from the edge of the first masking layer by a distance between 1 and 50 mm, more preferably between 2 and 20 mm, most preferably between 3 and 10 mm.

[0019] Preferably, the carrier film is polyvinyl butyral (PVB), which is advantageous since it also acts as an adhesive and flows during the autoclave permanent bonding step in the manufacturing process for the glazing.

[0020] Preferably, the thickness of the carrier film is 1 mm or less, preferably 100 μm or less, most preferably 50 μm or less.

[0021] Preferably, the ratio of the total area of ​​the carrier film to the total surface area of ​​the glazing is not more than 15%, more preferably not more than 5%, most preferably not more than 3%.

[0022] Preferably, the electric heating element is selected from a conductive coating, a conductive track, a conductor wire, or a combination thereof.

[0023] Preferably, the electric heating element is a conductive coating comprising a layer selected from silver, transparent conductive oxide, tin oxide, or fluorine doped tin oxide.

[0024] Preferably the electric heating elements are conductive tracks comprising printed silver, silver nanowires, carbon nanotubes or graphene, or etched copper.

[0025] Preferably, the electric heating element is a conductor comprising copper, tungsten, or silver.

[0026] Preferably, the electric heating element is a conductive coating having a sheet resistance of less than 325 Ω / □, more preferably less than 20 Ω / □, and most preferably less than 7 Ω / □.

[0027] Preferably, the power density in the electric heating element is between 100 and 3,000 W / m 2 , more preferably 200 to 2,000 W / m 2 , and most preferably 300 to 1,000 W / m 2 It is.

[0028] Preferably, the first busbar and the second busbar are arranged on the carrier film along opposite edges of the electric heating element.

[0029] Preferably, the first busbar and the second busbar are covered with a second masking layer.

[0030] Preferably, the first and second busbars comprise silver. The first and second busbars may be printed using a conductive ink comprising silver powder, silver spheres, graphite powder, graphite rods, carbon nanotubes, or glass flakes with a conductive coating. The first and second busbars may be copper strips. The first and second busbars may be etched copper, preferably of the same material as the etched copper conductive tracks of the electric heating element.

[0031] Preferably, the conductive tracks have a width of 1 μm to 5 mm, more preferably 5 μm to 4 mm, most preferably 10 μm to 1 mm.

[0032] In a second aspect, the present invention provides a method for manufacturing a glazing comprising the set of steps as claimed in claim 12.

[0033] The present invention provides a method for manufacturing a glazing of the present invention, comprising the steps of preparing a first glass sheet, depositing a first masking layer around an outer edge of the first glass sheet, arranging an aperture for a sensor in the first masking layer, and bonding a second glass sheet to the first glass sheet by a ply of interlayer material, and prior to the bonding step, positioning a carrier film between the ply of interlayer material and the first glass sheet or the second glass sheet, providing an electric heating element on the carrier film, and depositing the second masking layer on the carrier film.

[0034] Preferably, the second masking layer is deposited by digital printing.

[0035] Preferably, the first masking layer is deposited by screen printing.

[0036] Preferably, the conductive coating is deposited by sputtering, more preferably by chemical vapour deposition (CVD). Preferably, the conductive tracks are provided by etching a layer of conductive material, more preferably by etching a layer of copper. Preferably, the conductors are embedded in the carrier film by a wire routing device.

[0037] Preferably, the step of providing the electric heating elements on the carrier film precedes the step of depositing a second masking layer on the carrier film.

[0038] Preferably, the step of joining the second glass sheet to the first glass sheet by the ply of interlayer material is subsequent to the step of positioning a carrier film between the ply of interlayer material and the first glass sheet.

[0039] In a third aspect, the present invention provides the use of the glazing of the present invention as thermal windows in land, sea and air vehicles, for example as windscreens, rear windows, side windows, roof windows in automobiles. The present invention may also be used as windows in buildings, or as refrigerator doors or windows in street installations.

[0040] The present invention is disclosed herein by means of non-limiting figures, non-limiting examples and comparative examples. [Brief description of the drawings]

[0041] [Figure 1] 1 is an embodiment of the invention having straight inner edges. [Diagram 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Diagram 3] 1 is an embodiment of the present invention having rectangular inner edges. [Figure 4] FIG. 4 is a cross-sectional view taken along line AA in FIG. 3, with the heating element on the inner sheet. [Diagram 5] Similar to FIG. 4, but with a second masking layer on the inner sheet. [Figure 6] Similar to FIG. 4, but with the heating element on the outer sheet. [Figure 7] Similar to FIG. 4, but with a second masking layer on the outer sheet. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] FIG. 1 discloses an electric heating glazing (10) of the present invention comprising a first glass sheet (1) and a first masking layer (2) deposited on a surface of the first glass sheet (1).

[0043] The first glass sheet (1) is preferably soda-lime-silica glass produced by the float process. The glass preferably has a thickness of 2 to 12 mm. The first glass sheet (1) may be tempered glass having a surface stress of more than 65 MPa, heat-tempered glass having a surface stress of 40 to 55 MPa, semi-tempered glass having a surface stress of 20 to 25 MPa, or annealed glass.

[0044] The first glass sheet (1) may be the inner sheet of a pane of a laminated glass (10). The pane of the laminated glass (10) is adapted for the body of an automobile or the like, with the first glass sheet (1) facing towards the inside of the body. The first masking layer (2) is deposited on surfaces 4 (S4) of the panes of the laminated glass (10), numbered from surface 1 (S1) facing outwards.

[0045] The first masking layer (2) may comprise a black enamel deposited by screen printing a black ink in selected areas on the first glass sheet (1), which is then dried at a predetermined temperature for a predetermined time so that the printed ink becomes a hard enamel. Advantageously, the first masking layer (2) extends around the outer edge of the glazing (10) to mask an adhesive material, such as polyurethane, used to bond the glazing (10) to the vehicle body (not shown).

[0046] An aperture (3) is placed in the first masking layer (2) for a sensor (not shown). The sensor can be a camera, an RFID tag, or any electronic device that transmits or receives electromagnetic radiation. For example, a vehicle window can allow for the acquisition of data for toll collection or for an advanced driver assistance system (ADAS) to assist the driver in driving and parking. The sensor can be on a bracket on the surface of the first glass sheet (1). The sensor can be in a housing (not shown).

[0047] The carrier film (6) is provided within the glazing (10). The total area of ​​the carrier film (6) is usually larger than the total area of ​​the aperture (3).

[0048] The carrier film (6) is typically made of polyvinyl butyral (PVB). An electric heating element (7) is provided on a first surface of the carrier film (6). The electric heating element (7) is typically a conductive line, or wire, comprising silver printed or etched copper.

[0049] A second masking layer (8) is provided on the second surface of the carrier film (6). The second masking layer can be of any shape. For example, the second masking layer (8) can be a closed rectangular band. The second masking layer (8) can extend between the inner edge of the first masking layer (2) and the electric heating element (7).

[0050] FIG. 2 discloses a cross-section of the glazing (10) of the invention along line AA in FIG.

[0051] A first glass sheet (1) and a second glass sheet (4) are bonded together by a ply of interlayer material (5).

[0052] A first masking layer (2) is present on a surface of the first glass sheet (1) away from the ply of interlayer material (5). Typically, a first portion of the first masking layer (2) forms an obscuration band along the top edge of the first glass sheet (1). An aperture (3) for a sensor is present between the first portion of the first masking layer (2) and the second portion of the first masking layer (2). An unmasked area (11) is present between the second portion of the first masking layer (2) and a third portion of the first masking layer (2) along the bottom edge of the first glass sheet (1).

[0053] A carrier film (6) is positioned between the first glass sheet (1) and the ply of interlayer material (5). A heating element (7) is between the carrier film (6) and the first glass sheet (1). A second masking layer (8) is on a surface of the carrier film (6) opposite the side of the heating element (7) that faces the ply of interlayer material (5).

[0054] A third masking layer (12) is deposited on the surface of the second glass sheet (4) facing the ply of interlayer material (5). The third masking layer (12) covers at least a portion of the second masking layer (8).

[0055] Figure 3 discloses a glazing (10) of the invention similar to Figure 1, but further comprising a second masking layer (8) in the shape of an open rectangle, where open means having an inner edge surrounded by an outer edge, either or both of which edges are rectangular.

[0056] Figure 4 discloses a cross-section of the glazing (10) of the invention along the line AA in figure 3. The heating element (7) contacts the first glass sheet (1), which is advantageous for a fast heating of the surface 4 (S4), allowing for a faster removal of the haze.

[0057] Figure 5 is similar to Figure 4, but with a second masking layer (8) in contact with the first glass sheet (1) and a heating element (7) in contact with the ply of interlayer material (5). This is advantageous for heating the ply of interlayer material faster, providing an optimal balance between firstly defrosting surface 4 (S4) and secondly defrosting surface 1 (S1).

[0058] Figure 6 is similar to figure 4, but with the heating element (7) in contact with the second glass sheet (4) and the second masking layer in contact with the ply of interlayer material (5), which is advantageous for faster heating of surface 1 (S1), leading to faster removal of frost.

[0059] Figure 7 is similar to Figure 4, but with a second masking layer (8) in contact with the second glass sheet (4) and a heating element (7) in contact with the ply of interlayer material (5). This is advantageous for fast heating of the ply of interlayer material, providing an optimal balance between firstly defrosting surface 1 (S1) and secondly defrosting surface 4 (S4).

[0060] The heating element (7) may comprise a printed conductive track with a width of 400 μm to 700 μm, preferably comprising silver particles. The heating element (7) may comprise a copper wire with a diameter of 70 μm to 300 μm. The heating element (7) may comprise a tungsten wire with a diameter of 10 μm to 50 μm. The heating element (7) may be formed by etching a layer of copper on the carrier film (6), resulting in a conductive track with a width of 1 μm to 50 μm. [Explanation of symbols]

[0061] The reference symbols in the drawings are as follows: 1 First glass sheet (inner sheet) 2. First Masking Layer 3 Aperture 4 Second glass sheet (outer sheet) 5 Plies of Interlayer Material 6. Carrier Film 7 Electric heating element 8 Second Masking Layer 9 Busbar 10 Glazing 11 Unmasked Area 12 Third Masking Layer S1 First Surface S2 Second Surface S3 Third Surface S4 The Fourth Surface

Claims

1. A glazing (10) for electric heating, comprising: a first glass sheet (1); a first masking layer (2) around the outer edge of the first glass sheet (1); an aperture (3) for a sensor in said first masking layer (2); a second glass sheet (4) joined to said first glass sheet (1) by a ply (5) of interlayer material; a carrier film (6) disposed between the ply of interlayer material (5) and the first glass sheet (1); an electric heating element (7) on said carrier film (6); a second masking layer (8) on said carrier film (6); A glazing (10) comprising:

2. 2. The glazing (10) according to claim 1, wherein the second masking layer (8) is on the surface of the carrier film (6) opposite the electric heating element (7).

3. 3. The glazing (10) according to claim 1 or 2, wherein the electric heating element (7) is in contact with the first glass sheet (1).

4. 3. The glazing (10) according to claim 1 or 2, wherein the second masking layer (8) has an inner edge, the shape of which is selected from a straight line, an arcuate shape, an ellipse, a circle, a triangle, a square, a rectangle, a parallelogram, or a trapezoid.

5. 3. The glazing (10) according to claim 1 or 2, wherein the second masking layer (8) has an outer edge, and the width between the inner edge and the outer edge is 1 to 100 mm, more preferably 3 to 30 mm, and most preferably 5 to 25 mm.

6. 3. The glazing (10) according to claim 1 or 2, wherein the inner edge of the second masking layer (8) is spaced apart from the edge of the first masking layer by a distance of 1 to 50 mm, more preferably 2 to 20 mm, and most preferably 3 to 10 mm.

7. 3. The glazing (10) according to claim 1 or 2, wherein the carrier film (6) consists of polyvinyl butyral.

8. 3. The glazing (10) according to claim 1 or 2, wherein the thickness of the carrier film is 1 mm or less, preferably 100 μm or less, most preferably 50 μm or less.

9. 3. The glazing (10) according to claim 1 or 2, wherein the electric heating element (7) is selected from an electrically conductive coating, an electrically conductive track, a conducting wire, or a combination thereof.

10. 3. The glazing (10) according to claim 1 or 2, wherein the electric heating element (7) is a conductive track comprising silver printing, silver nanowires, carbon nanotubes or graphite, or etched copper.

11. The glazing (10) according to claim 1 or 2, wherein the power density in the heated coating is between 100 and 3,000 W / m ２ , more preferably 200 to 2,000 W / m ２ , most preferably 300 to 1,000 W / m ２ That is, glazing (10).

12. A method for manufacturing an electric heating glazing (10), comprising the steps of: Providing a first glass sheet (1); depositing a first masking layer (2) around the outer edge of the first glass sheet (1); Placing an aperture (3) for a sensor in said first masking layer (2); bonding a second glass sheet (4) to said first glass sheet (1) by means of a ply (5) of interlayer material; and Before the joining step, positioning a carrier film (6) between the ply of interlayer material (5) and the first glass sheet (1) or the second glass sheet (4); Providing an electric heating element (7) on said carrier film (6); depositing a second masking layer (8) onto said carrier film (6); A method for manufacturing an electric heating glazing (10) comprising:

13. 13. The method for manufacturing a glazing (10) according to claim 12, wherein the second masking layer (8) is deposited by digital printing.

14. 14. A method for manufacturing a glazing (10) according to claim 12 or 13, wherein the first masking layer (2) is deposited by screen printing.

15. 10. Use of a glazing (10) according to claim 1 as a windscreen, rear window, side window or roof window of a motor vehicle, or as a window of a building, or as a window of a refrigerator door or street installation.

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