METHOD FOR PRODUCING A COMPOSITE PANE HAVING A CORROSION-PROTECTED FUNCTIONAL COATING

Abstract

Methods and devices for producing a composite pane having a functional coating are presented. The functional coating is applied to part of a surface of a base pane, and a first pane is cut out from the base pane while introducing a frame-shaped peripheral coating-free region into the functional coating having an inner region that is not adjacent a side edge of the first pane. The surface of the first pane with the functional coating is then bonded via a thermoplastic intermediate layer to a surface of a second pane.

Claims

1-15. (canceled)

16. A method for producing a composite pane having a functional coating, the method comprising: a) applying a functional coating to part of a surface of a base pane; b) cutting out a first pane from the base pane while introducing at least one coating-free region into the functional coating, wherein the at least one coating-free region completely surrounds an inner region of the functional coating and separates the inner region from an outer region that partially or completely surrounds the inner region; and c) bonding, via a thermoplastic intermediate layer, a surface of the first pane having the functional coating to a surface of a second pane.

17. The method according to claim 16, wherein: introducing of the at least one coating-free region is performed via a decoating tool with a laser beam, and cutting out of the first pane is performed via a cutting tool with a cutting wheel and a cooling fluid.

18. The method according to claim 17, wherein: the cutting wheel is guided directly on the coated surface of the first pane, and the laser beam is shone onto the first pane through a surface of the first pane facing away from the coated surface of the first pane and is guided through the first pane onto the functional coating.

19. The method according to claim 18, wherein the cutting tool and the decoating tool are moved simultaneously and the laser beam is guided onto the functional coating in a region covered by the cooling fluid.

20. A device for carrying out the method according to claim 16, the device comprising: a cutting tool for cutting the first pane out of the base pane; a decoating tool for introducing the at least one coating-free region into the functional coating applied on the base pane, and a moving device for moving the cutting tool and the decoating tool.

21. The device according to claim 20, wherein: the cutting tool is cooled with a cooling fluid and comprises one of a cutting wheel and a diamond tip, and the decoating tool comprises a laser beam.

22. The device according to claim 21, wherein the decoating tool and the cutting tool are arranged on opposite sides of a plane in which the base pane can be arranged.

23. The device according to claim 20, wherein the moving device includes one or more of: a) a robot, b) a multi-axis handling device, and c) an X-Y positioning table.

24. A composite pane with a functional coating produced in accordance with the method according to claim 16, the composite pane comprising: a first pane; a second pane; and a thermoplastic intermediate layer, wherein a surface of the first pane is areally bonded by the thermoplastic intermediate layer to a surface of the second pane, wherein the surface of the first pane comprises: at least one functional coating that is applied on part of the surface of the first pane, at least one coating-free region that completely surrounds an inner region of the functional coating.

25. The composite pane according to claim 24, wherein the coating-free region is strip-shaped and is arranged substantially parallel to side edges of the first pane.

26. The composite pane according to claim 24, wherein a width d.sub.1/2 of the coating-free region is from 30 μm to 30 mm.

27. The composite pane according to claim 26, wherein the width d.sub.1/2 is from 100 μm to 2 mm.

28. The composite pane according to claim 26, wherein the width d.sub.1/2 is from 250 μm to 1.5 mm.

29. The composite pane according to claim 26, wherein the width d.sub.1/2 is from 250 μm to 500 μm.

30. The composite pane according to claim 24, wherein the inner region of the functional coating is partially or completely surrounded by at least one outer region of the functional coating.

31. The composite pane according to claim 30, wherein a width b.sub.1/2 of the outer region is from 0.5 mm to 30 mm.

32. The composite pane according to claim 30, wherein a width b.sub.1/2 of the outer region is from 3 mm to 11 mm.

33. The composite pane according to claim 24, wherein the at least one coating-free region comprises a first coating-free region and a second coating-free region, the first coating-free region being completely bordered by the second coating-free region.

34. The composite pane according to claim 33, wherein the at least one coating-free region further comprises a third coating-free region, the second coating-free region being completely bordered by the third coating-free region.

35. The composite pane according to claim 24, wherein at least one of the first pane and the second pane contains glass or polymers.

36. The composite pane according to claim 35, wherein the glass comprises one of: a) flat glass, b) float glass, c) quartz glass, d) borosilicate glass, and e) soda lime glass.

37. The composite pane according to claim 35, wherein the polymers comprise on or more of: a) polyethylene, b) polypropylene, c) polycarbonate, and d) polymethylmethacrylate.

38. The composite pane according to claim 24, wherein the functional coating contains silver (Ag), indium tin oxide (ITO), fluorine-doped tin oxide (SnO.sub.2:F), or aluminum doped zinc oxide (ZnO:Al).

Description

[0092] FIG. 1A a perspective view of a schematic representation of a device according to the invention for carrying out the method according to the invention;

[0093] FIG. 1B a cross-sectional view along the section line E-E of a base pane 1′ of FIG. 1A;

[0094] FIG. 1C a cross-sectional view of an alternative device according to the invention for carrying out the method according to the invention along the section line E-E′ of a base pane 1′ based on FIG. 1A:

[0095] FIG. 2 a detailed flowchart of an embodiment of the method according to the invention;

[0096] FIG. 3A a cross-sectional view along the section line F-F′ of a first pane 1 of FIG. 1A after step (b) of the method according to the invention;

[0097] FIG. 3B a cross-sectional view along the section line F-F′ of a first pane 1 of FIG. 1A after step (c) of the method according to the invention;

[0098] FIG. 4A a plan view of an embodiment of a composite pane with a functional coating according to the invention,

[0099] FIG. 4B a cross-sectional view along the section line B-B′ of the composite pane according to the invention of FIG. 4A,

[0100] FIG. 5A a plan view of an alternative embodiment of a composite pane with a functional coating according to the invention,

[0101] FIG. 5B a cross-sectional view along the section line A-A′ of the composite pane of FIG. 5A,

[0102] FIG. 6A a plan view of another embodiment of the composite pane with a functional coating according to the invention,

[0103] FIG. 6B a cross-sectional view along the section line B-B′ of the composite pane according to the invention of FIG. 6A,

[0104] FIG. 7A a plan view of another embodiment of the composite pane with a functional coating according to the invention,

[0105] FIG. 7B a cross-sectional view along the section line C-C′ of the composite pane according to the invention of FIG. 7A,

[0106] FIG. 8A a plan view of another embodiment of the composite pane with a functional coating according to the invention,

[0107] FIG. 8B a cross-sectional view along the section line D-D′ of the composite pane according to the invention of FIG. 8A,

[0108] FIG. 1A depicts a perspective view of a schematic representation of a device 30 according to the invention for carrying out the method according to the invention. The device 30 includes a cutting tool 18 for cutting out a first pane 1 from a larger pane, which is referred to in the following as the base pane 1′. A functional coating 3 is arranged on the base pane 1′.

[0109] FIG. 1B depicts a cross-sectional view of the device 30 according to the invention of FIG. 1A along a cutting plane, that runs parallel to the section line E-E′ and orthogonal to the base pane 1′.

[0110] The cutting tool 18 is, in this example, a cutting wheel 16 made of a hard metal. It is understood that other cutting tools 18 such as a diamond needle or a laser can also be used. It is likewise understood that the cutting tool 18, in the case of a base pane 1′ made of glass, only cuts into it or scores it and the first pane 1 subsequently breaks out of the base pane 1′, for example, by means of a slight mechanical load.

[0111] The device 30 further includes a decoating tool 17 for introducing a coating-free region 9.1 into the functional coating 3. The decoating tool 17 is, in this example, a laser beam 15. The laser beam 15 is guided onto the functional coating 3 on the surface III of the base pane 1′. There, the functional coating 3 is ablated under the action of the laser beam 15, for example, by vaporization.

[0112] It is understood that the decoating tool 17 can also be a grinding wheel or another suitable tool.

[0113] The device 30 according to the invention further includes a moving device 19 with which the cutting tool 18 and the decoating tool 17 can be moved. In this example, the moving device 19 is an X-Y positioning table 20, which simultaneously displaces tools 18,19 in the plane of the base pane 1′. Any other suitable device can be used as moving device 19, for example, a multi-axis handling device or a robot.

[0114] Likewise, the decoating tool 17 and, in particular, the laser can be arranged on the other side of the base pane 1′ such that the laser beam 15 is guided through the first pane 1 and only then strikes the functional coating 3. This arrangement has the particular advantage that vaporized material of the functional coating 3 cannot enter the path of the laser beam 15 such that the beam is not scattered and is not weakened, and higher patterning accuracy is achieved.

[0115] FIG. 10 depicts an alternative embodiment of a device according to the invention for carrying out the method according to the invention. In this case, the decoating tool 17 is a laser, which is arranged on the side of the base pane 1′ opposite the cutting tool 18 in comparison with FIG. 1B such that the laser beam 15 is guided through the first pane 1 and only then strikes the functional coating 3. Preferably, the cutting wheel 16 of the cutting tool 18 is cooled together with a region of the functional coating 3 with a cooling fluid 21, for example, a cutting oil, which wets at least a region of the functional coating 3. Advantageously, the laser beam 15 passes through the first pane 1 onto the functional coating 3, which is wetted with the cooling fluid 21 on the side facing away from the first pane 1. The laser beam 15 can be guided immediately adjacent the contact point between the cutting wheel 16 and the functional coating 3, or following a track, which leaves behind the cooling fluid on the functional coating 3 after the processing with the cutting wheel 16. This arrangement has the particular advantage that vaporized material of the functional coating 3 is bound by the cooling fluid 21 and, hence, cannot diffuse through the arrangement or be deposited on adjacent sections of the functional coating 3. Typically, the cooling fluid 21 remaining on the surface of the first pane 1 is washed off in another process step and, with it, the ablated material of the functional coating 3 bound in the cooling fluid 21 is also removed.

[0116] FIG. 2 depicts a flowchart of an exemplary embodiment of the method according to the invention for producing a composite pane 100 with a functional coating 3.

[0117] In step (a), a functional coating 3 is applied on the surface Ill of a base pane 1′, for example, by cathodic sputtering.

[0118] In step (b), a first pane 1 is cut out or scored from the base pane 1′ by a cutting tool 18, and at least one frame-shaped peripheral coating-free region 9.1 is introduced by a decoating tool 17 into the functional coating 3, wherein on the first pane 1, an inner region 11 of the functional coating 3 is completely separated from an outer region 10.1 of the functional coating 3 such that the inner region 11 is not adjacent a side edge 6 of the first pane 1.

[0119] In step (c), the surface Ill of the first pane 1 with the functional coating 3 is bonded via a thermoplastic intermediate layer 4 to a surface II of a second pane 2.

[0120] FIG. 3A depicts a cross-sectional view along the section line F-F′ of the first pane 1 after process step (b). In a coating-free region 9.1, the functional coating 3 is completely removed over a width d.sub.1. The functional coating 3 is thus divided into an inner region 11 and an outer region 10.1. This means that there is no longer a material connection of the material of the functional coating 3 of the inner region 11 to the outer region 10.1.

[0121] Then, in step (c), the first pane 1 is bonded to a second pane 2 via a thermoplastic intermediate layer 4 using customary lamination processes, for example, in the autoclave. FIG. 3B depicts the laminated composite pane 100 that was prepared in accordance with the method according to the invention.

[0122] FIG. 4A depicts a plan view of an exemplary embodiment of a composite pane 100 with a functional coating 3 according to the invention. FIG. 4B depicts a cross-sectional view along the section line B-B′ of the composite pane according to the invention 100 of FIG. 4A. The composite pane 100 comprises a first pane 1, a second pane 2, and a thermoplastic intermediate layer 4, which areally bonds the surface III of the first pane 1 to the surface 11 of the second pane 2. The first pane 1 and the second pane 2 are made, for example, of soda lime glass. The thickness of the first pane 1 is, for example, 1.6 mm and the thickness of the second pane 2 is 2.1 mm. The thermoplastic intermediate layer 4 is made, for example, of polyvinyl butyral (PUB) and has a thickness of 0.76 mm. The dimensions of the composite pane 100 are, for example, 1 m×1 m.

[0123] A functional coating 3 of a transparent electrically conductive coating, which can, for example, serve as an infrared reflecting layer or an electrical heating layer, is applied on the surface III of the first pane 1. The functional coating 3 is a layer system, which includes, for example, three electrically conductive silver layers that are separated from one another by dielectric layers.

[0124] The functional coating 3 extends, for example, over the entire surface III of the first pane 1 minus a frame-shaped peripheral coating-free region 9.1, which separates an inner region 11 of the functional coating 3 completely from an outer region 10.1 of the functional coating 3. This means that the inner region 11 is not adjacent a side edge 6 of the first pane 1. In the example depicted here, the frame-shaped peripheral coating-free region 9.1 has the shape of a rectangular and, in this case, square decoated line with a width d.sub.1, which is set back into the pane interior over the complete perimeter by a distance b.sub.1 from the side edge 6 of the composite pane 100. The distance b.sub.1 is, in this case, the width of the outer region 10.1 and is, for example, 5 mm. The width d.sub.1 of the coating-free region 9.1 is, for example, constant and is, for example, 300 μm. This arrangement prevents the inner region 11 of the functional coating 3 from being adjacent the side edge 6 of the first pane 1. In the composite pane 100, the functional coating 3 is thus prevented from having direct access to the atmosphere outside the composite pane 100. By means of the lamination of the first pane 1 and the second pane 2 with the intermediate layer 4, the coating-free region 9.1 is completely filled with the material of the intermediate layer 4, and the inner region 11 is hermetically sealed. The functional coating 3 in the inner region 11 is thus effectively protected against moisture and, hence, against corrosion. As investigations of the inventors surprisingly revealed, a width d.sub.1 of only 30 μm suffices to protect the functional coating 3 in the inner region 11 against corrosion. It is understood that even more sections of the functional coating 3 can be coating-free within the inner region 11 or the outer region 10.1, without the above-described effect of corrosion protection according to the invention being impaired. The narrow coating-free region 9.1 can, for example, be produced by laser decoating of the functional coating 3. This has the particular advantage that the composite pane 100 according to the invention can be produced quickly and economically.

[0125] FIG. 5A depicts a plan view of an alternative embodiment of a composite pane 101 according to the invention. FIG. 5B depicts a cross-sectional view along the section line A-A′ of the composite pane of FIG. 5A. The basic structure of the composite pane 101 corresponds in the materials and the dimensions of the composite pane 100 according to the invention of FIG. 4A and FIG. 4B. The composite pane 101 likewise has a functional coating 3, which is arranged on the surface Ill of the first pane 1.

[0126] In contrast to the composite pane 100 according to the invention of FIG. 4 A and FIG. 4B, the composite pane 101 has, in the edge region 12 of the first pane 1, a coating-free region 9.1 with a width d.sub.1 of 15 mm, which extends all the way to the pane edge 6. In other words, the composite pane 101 has no outer region 9.1 made of a functional coating 3:

[0127] FIG. 6A depicts a plan view of an alternative embodiment of a composite pane 100 according to the invention with a functional coating 3. FIG. 6B depicts a cross-sectional view along the section line B-B′ of the composite pane 100 according to the invention of FIG. 6A. The structure of the composite pane 100 of FIG. 6A and FIG. 6B corresponds substantially to the structure of the composite pane 100 of FIG. 4A and 4B such that, in the following, only the differences between the two composite panes 100 are described.

[0128] The functional coating 3 likewise extends, as in the example of FIG. 4A, over the entire surface III of the first pane 1 minus a frame-shaped peripheral coating-free region 9.1, which completely separates an inner region 11 of the functional coating 3 from an outer region 10.1 of the functional coating 3 such that the inner region 11 is not adjacent a side edge 6 of the first pane 1. In contrast to FIG. 4A, in the example of FIG. 6A, the coating-free region 9.1 is formed by strips that run parallel to the side edges 6 of the first pane 1. The strips intersect in each case in the corner regions of the first pane 1. A frame-shaped peripheral region that corresponds to the coating-free region 9.1 and that completely separates the functional coating 3 from the side edge 6 of the first pane 1 is created by the intersecting strips. Thus, in the finished composite pane 100, the functional coating 3 in the inner region 11 is hermetically sealed from the surroundings of the composite pane 100 and is protected against moisture penetrating from outside. In contrast to the exemplary embodiment of FIG. 4A, the coating-free region 9.1 in FIG. 6A has extension elements 16 that extend the coating-free region 9.1 all the way to the side edge 6 in the corner regions of the first pane. Since these are also hermetically sealed after lamination with the thermoplastic intermediate layer 4, here, again, no moisture can reach the functional coating 3 in the inner region 11. Coating-free regions 9.1 made of such parallel running strips can be produced particularly simply from a production technology standpoint, for example, by parallel guidance of a decoating tool for the decoating of the coating-free region 9.1, such as a laser, to another tool that cuts out the first pane 1 from a larger base pane or scores it for separation.

[0129] FIG. 7A depicts a plan view of an alternative embodiment of a composite pane 100 according to the invention with a functional coating 3. FIG. 7B depicts a cross-sectional view along the section line C-C′ of the composite pane 100 according to the invention of FIG. 7A. The structure of the composite pane 100 of FIG. 7A and FIG. 7B corresponds substantially to the structure of the composite pane 100 of FIG. 6A and 6B such that, in the following, only the differences between the two composite panes 100 are described.

[0130] The composite pane 100 depicted in this example has, in addition to the coating-free region 9.1, other coating-free regions 9.2, which is framed by the coating-free region 9.1. The coating-free region 9.2 has, for example, a width d.sub.2 of 100 μm and a distance b.sub.2 from the coating-free region 9.1 of 2 mm. Both coating-free regions 9.1,9.2 are formed by strips running parallel to the side edge 6 of the first pane 1, which intersect in the corners of the first pane 1 in each case and have extension elements 16. This means that the inner region 11 of the functional coating 3 of the first pane 1 is separated from the side edge 6 at least by a decoated region 9.1 of the width d.sub.1 and a decoated region 9.2 of the width d.sub.2. In the finished composite pane 1, this results in a widened and, thus, improved separation of the inner region 11 from the atmosphere surrounding the composite pane 100 and, thus, in improved protection against moisture and, thus, against corrosion.

[0131] FIG. 8A depicts a plan view of another exemplary embodiment of a composite pane 100 according to the invention with a functional coating 3 in the form of an electrical heating layer. The composite pane 100 comprises a first pane 1 and a second pane 2, which are bonded to one another via a thermoplastic intermediate layer 4. The composite pane 100 is, for example, a motor vehicle pane and, in particular, the windshield of a passenger car. The first pane 1 is, for example, intended to face the interior in the installed position. The first pane 1 and the second pane 2 are made of soda lime glass. The thickness of the first pane 1 is, for example, 1.6 mm and the thickness of the second pane 2 is 2.1 mm. The thermoplastic intermediate layer 4 is made of polyvinyl butyral (PVB) and has a thickness of 0.76 mm. A functional coating 3 made of an electrically conductive coating that can be used as an electrical heating layer is applied on the inside surface III of the first pane 1. The functional coating 3 is a layer system that includes, for example, three electrically conductive silver layers that are separated from one another by dielectric layers. When a current flows through this electrically conductive functional coating 3, it is heated as a result of its electrical resistance and Joule heating. Consequently, the functional coating 3 can be used for active heating of the composite pane 100.

[0132] The functional coating 3 extends, for example, over the entire surface III of the first pane 1 minus a peripheral frame-shaped coating-free region 9.1 with a width d.sub.1 of 100 μm. The coating-free region 9.1 is offset into the pane interior by a distance b.sub.1 of, for example, 5 mm from the pane edge 6. Here, the coating-free region 9.1 has two technical functions: it serves for the electrical insulation between the car body and the voltage-carrying functional coating 3 when it is heated electrically. Furthermore, the coating-free region 9.1 is hermetically sealed by adhesive bonding to the intermediate layer 4 and protects the functional coating 3 in the inner region 11 against damage and moisture and, hence, against corrosion.

[0133] For the electrical contacting of the functional coating 3 serving as an electrical heating layer, a first busbar 5.1 is arranged in the lower edge region and a second busbar 5.2 is arranged in the upper edge region of the inner region 11 on the functional coating 3 in each case. The busbars 5,1, 5.2 include, for example, silver particles and were applied in the screen printing method and then fired. The length of the busbars 5.1, 5.2 corresponds approx. to the dimension of the inner region 11 of the functional coating 3.

[0134] When an electrical voltage is applied on the busbars 5.1 and 5.2, a uniform current flows through the electrically conductive functional coating 3 between the busbars 5.1,5.2. A supply line 7 is arranged approx. centrally on each busbar 5.1,5.2. The supply line 7 is a foil conductor known per se. The supply line 7 is electrically conductively connected to the busbar 5.1, 5.2 via a contact surface, for example, using a soldering compound, an electrically conductive adhesive, or by simple placement and contact pressure inside the composite pane 100. The foil conductor includes, for example, a tinned copper foil with a width of 10 mm and a thickness of 0.3 mm. Via the electrical supply lines 7, the busbars 5.1,5.2 are connected via connecting cables 13 to a voltage source 14 that provides an onboard voltage typical for motor vehicles, preferably from 12 V to 15 V and, for example, roughly 14 V. Alternatively, the voltage source 14 can also have higher voltages, for example, from 35 V to 50 V and, in particular, 42 V or 48 V.

[0135] It is understood that the functional coating 3 can also have, in addition to the heating function, further functions, such as infrared reflection or low-E properties.

[0136] An uncoated zone 8 is arranged in the composite pane 100, roughly centrally to the pane width. The uncoated zone 8 has no electrically conductive material of the functional coating 3. Here, the uncoated zone 8 is, for example, completely surrounded by the functional coating 3. Alternatively, the uncoated zone 8 can be arranged on the edge of the functional coating 3. The area of the uncoated zone 8 is, for example, 1.5 dm.sup.2. On its lower end, the uncoated zone 8 is adjacent an additional busbar 5.3 that borders the uncoated zone 8 on the bottom. The uncoated zone 8 serves, for example, as a communication, sensor, or camera window.

[0137] The busbars 5.1,5.2,5.3 have, in the example depicted, a constant thickness of, for example, roughly 10 μm and a constant specific resistance of, for example, 2.3 μohm.Math.cm.

[0138] The composite panes 100,101 produced in accordance with the method according to the invention were subjected to customary corrosion tests.

[0139] a) a moisture test at a temperature of 70° C. and a relative humidity of 100% for a period of 300 hours, as well as

[0140] b) an alternating climate test with 20 cycles of 12-hour duration each at a relative humidity of 85% and a temperature change from 85° C. to −40° C.

[0141] c) a salt spray test at a temperature of 35° C. for 960 hours with an aqueous sodium chloride solution

[0142] All composite panes 100,101 produced according to the invention demonstrate very good corrosion resistance in the above-mentioned corrosion tests.

LIST OF REFERENCE CHARACTERS

[0143] 1 first pane

[0144] 2 second pane

[0145] 3 functional coating

[0146] 4 thermoplastic intermediate layer

[0147] 5.1,5.2,5.3 busbar

[0148] 6 side edge of he first pane 1

[0149] 7 supply line

[0150] 8 uncoated zone, communication window

[0151] 9.1,9.2 coating-free region

[0152] 10.1,10.2 outer region

[0153] 11 inner region

[0154] 12 edge region

[0155] 13 connecting cable

[0156] 14 voltage source

[0157] 15 laser beam

[0158] 16 cutting wheel

[0159] 17 decoating tool

[0160] 18 cutting tool

[0161] 19 moving device

[0162] 20 X-Y positioning table

[0163] 21 cooling fluid

[0164] 30 device according to the invention

[0165] 100,101 composite pane according to the invention

[0166] II surface of the second pane 2

[0167] III inner surface of the first pane 1

[0168] IV outer surface of the first pane 1

[0169] A-A′, B-B′, C-C′, D-D′, E-E′, F-F′ section line

[0170] b.sub.1, b.sub.2 width of the outer region 10.1,10,2

[0171] d.sub.1, d.sub.2 width of the coating-free region 9.1,9.2

[0172] x,y direction