TRANSPARENT PANE WITH HEATED COATING

Abstract

A transparent pane having at least one heatable, electrically conductive coating is presented. Application of a supply voltage causes a heating current to flow over a heating field. The heating field contains at least one coating-free zone.

Claims

1.-14. (canceled)

15. A transparent pane comprising: at least one heatable, electrically conductive coating connected to at least two collection lines configured to establish an electrical connection to two poles of a voltage source, so that an applied supply voltage of the voltage source causes a heating current to flow over a heating field formed between the at least two collection lines, wherein the heating field contains at least one coating-free zone that is delimited by a zone edge of the coating-free zone, the zone edge being formed, at least in sections, by a region of the electrically conductive coating that is surrounded, at least in sections, by at least one additional electrode, wherein the at least one additional electrode is electrically connected to the at least two collection lines via the heating field of the coating, and wherein the at least two collection lines have a bright, silver color and the at least one additional electrode has a dark color, wherein production of the at least two collection lines comprises a silver paste with a silver content from 70 to 90 wt.-%, based on the total amount of the silver paste, and production of the at least one additional electrode comprises a silver paste with a silver content from 50 to <70 wt.-%, based on the total amount of the silver paste.

16. The transparent pane according to claim 15, wherein an electrical conductivity of the at least one additional electrode is 0.05 to 0.3 times an electrical conductivity of the at least two collection lines.

17. The transparent pane according to claim 15, wherein the at least two collection lines have a bright, silver color with a luminance L* so that L*>65, or the at least one additional electrode has a dark color with a luminance L* so that L*≦65, the luminance L* being defined according to the EN ISO 11664-4 color space.

18. The transparent pane according to claim 17, wherein the luminance L* of the at least two collection lines satisfies L*>80.

19. The transparent pane according to claim 18, wherein the luminance L* of the at least one additional electrode satisfies L*<50.

20. The transparent pane according to claim 15, wherein the at least two collection lines have a bright, silver color with a luminance L* so that L*>65, and the at least one additional electrode has a dark color with a luminance L* so that L*≦65, the luminance L* being defined according to the EN ISO 11664-4 color space.

21. The transparent pane according to claim 15, wherein the at least one additional electrode runs, at least in sections, according to one or more of: a) rectilinear, b) wave-shaped, c) meander-shaped, d) sawtooth-shaped, and e) zigzag-shaped.

22. The transparent pane according to claim 15, wherein the at least one additional electrode and the at least two collection lines are produced in one process step using two different silver pastes.

23. The transparent pane according to claim 22, wherein the at least one additional electrode and the at least two collection lines are produced by screenprinting.

24. The transparent pane according to claim 15, wherein the at least one coating-free zone is spatially associated with the upper collection line in an installed state of the transparent pane.

25. The transparent pane according to claim 15, wherein the coating-free zone is covered, in sections, by a masking strip.

26. A method for producing a transparent pane, the method comprising the following process steps: (A) producing an electrically conductive coating, (B) producing at least one coating-free zone in the electrically conductive coating, (C) producing at least two collection lines connected to two poles of a voltage source, the at least two collection lines being electrically connected to the electrically conductive coating so that by application of a supply voltage of the voltage source, a heating current flows over a heating field situated between the two collection lines, and (D) producing at least one additional electrode for electrical connection to the at least two collection lines, the at least one additional electrode surrounding, at least in sections, the at least one coating-free zone.

27. The method according to claim 26, wherein the process steps (C) and (D) are performed simultaneously using screenprinting.

28. The method according to claim 26, wherein the step of producing the at least two collection lines comprises using a silver paste that delivers bright, silver colored collection lines, and wherein the step of producing the at least one additional electrode comprises using a silver paste that delivers dark additional electrodes.

29. The method according to claim 28, wherein the silver paste used for the producing of the at least two collection lines has a silver content from 70 to 90 wt.-%, based on the total amount of the silver paste, and wherein the silver paste used for the producing of the at least one additional electrode has a silver content from 50 to <70 wt.-%, based on the total amount of the silver paste.

30. The method according to claim 26, wherein the process steps C and D are implemented such that an electrical conductivity of the at least one additional electrode is 0.05 to 0.3 times an electrical conductivity of the at least two collection lines.

31. A method comprising using the transparent pane according to claim 15, as a functional and/or decorative individual piece and as a built-in component in furniture, appliances, buildings, and means of transportation.

32. A method comprising using the transparent pane produced according to the method of claim 26 as a functional and/or decorative individual piece and as a built-in component in furniture, appliances, buildings, and means of transportation.

Description

[0115] The invention is now explained in detail using exemplary embodiments, reference being made to the accompanying drawings. They depict, in simplified, not-to-scale representation:

[0116] FIG. 1 a plan view of an exemplary embodiment of the windshield according to the invention;

[0117] FIG. 2 a view of a vertical section through a detail of the windshield according to the invention of FIG. 1;

[0118] FIG. 3 a perspective sectional view of a detail of the windshield of FIG. 1;

[0119] FIG. 4 a plan view of a second exemplary embodiment of the windshield according to the invention;

[0120] FIG. 5 a plan view of yet a third exemplary embodiment of the windshield according to the invention, and

[0121] FIG. 6 a plan view of a fourth exemplary embodiment of the windshield according to the invention.

[0122] In FIGS. 1 through 6, the reference characters have the following meaning: [0123] 1 windshield [0124] 2 outer pane [0125] 3 inner pane [0126] 4 adhesive layer [0127] 5 pane edge [0128] 6, 6′ first side [0129] 7, 7′ second side [0130] 8 electrically conductive coating [0131] 8′ subregions of the electrically conductive coaling 8 outside the heating field 12 [0132] 9 peripheral coating-free edge strip [0133] 10 coating edge [0134] 11, 11′ collection line [0135] 12 heating field [0136] 13 masking strip [0137] 13′ edge of the masking strip [0138] 14 first coating-free zone [0139] 14′ second coating-free zone [0140] 14″ third coating-free zone [0141] 15, 15′ 15″ additional electrode surrounding, at least in sections, the first coating-free zone 14 [0142] 16 zone edge of the first coating-free zone 14 formed by the electrically conductive coating 8

[0143] FIG. 1 depicts a transparent windshield 1 of a motor vehicle viewed from the inside. The windshield 1 is implemented here, for example, as a composite glass pane, whose structure is illustrated using the view of a vertical section through a detail of the windshield 1 in FIG. 2 and using the perspective sectional view of the detail of the windshield 1 in FIG. 3.

[0144] Accordingly, the windshield 1 comprises two rigid individual panes, namely, an outer pane 2 and an inner pane 3, which are permanently bonded to one another by a thermoplastic adhesive layer 4, here, for example, a polyvinyl butyral film (PVB), an ethylene vinyl acetate film (EVA), or a polyurethane film (PU). The two individual panes 2, 3 are approx. the same size and shape and can, for example, have a trapezoidal curved contour, which is indicated in the figures. They are made, for example, of glass, also possibly made of a non-glass material such as plastic. For applications other than windshields, it would also be possible to produce the two individual panes 2, 3 from a flexible material. The contour of the windshield 1 results from a pane edge 5 common to the two individual panes 2, 3, with the windshield 1 having, at the top and the bottom, two first sides 6, 6′ positioned opposite one another as well as, on the left and the right, two second sides 7, 7′ positioned opposite one another.

[0145] As shown in the FIGS. 2 and 3, a transparent, electrically conductive coating 8 is deposited on the side of the inner pane 3 bonded to the adhesive layer 4. Here, the heatable, electrically conductive coating 8 is, for example, applied substantially on the full surface of the inner pane 3, with a peripheral edge strip 9 on all sides not coated such that a coating edge 10 of the electrically conductive coating 8 is set back inward relative to the pane edge 5. By this means, electrical isolation of the electrically conductive coating 8 toward the outside is realized. In addition, the electrically conductive coating 8 is protected against corrosion penetrating from the pane edge 5.

[0146] The electrically conductive coating 8 comprises, in a known manner, a layer sequence (not shown) with at least one electrically heatable, metallic sublayer, preferably silver, and, optionally, other sublayers such as antireflection and blocker layers. Advantageously, the layer sequence has high thermal stability such that it withstands the temperatures required for the bending of glass panes of typically more than 600° C. without damage, but with the possibility of also providing layer sequences that have lower thermal stability. The electrically conductive coating 8 can equally be applied as a metallic single layer. It is likewise conceivable to apply the electrically conductive coating 8 not directly on the inner pane 3, but, instead, to first apply it on a carrier, for example, a plastic film, which is subsequently adhesively bonded to the outer and inner pane 2, 3. Alternatively, the carrier film can be bonded to adhesive films (e.g., PVB films) and adhesively bonded as a three-layer arrangement (trilayer) to inner and outer pane 2, 3. The heatable, electrically conductive coating 8 is preferably applied by sputtering or by magnetron cathode sputtering on the inner or outer pane 2, 3.

[0147] As shown in FIG. 1, the electrically conductive coating 8 is electrically conductively connected adjacent the first sides 6, 6′, i.e., on the upper and lower pane edge 5, to a band-shaped upper collection line or busbar 11 and to a band-shaped lower collection line 11′ and, for this purpose, galvanically coupled to the two collection lines 11, 11′, for example. The upper collection line 11 is provided for connecting to one pole of a voltage source (not shown). The lower collection line 11′ is provided for connecting to the opposite pole of the voltage source (not shown). The two collection lines 11, 11′ of opposite polarity serve for uniform introduction and distribution of the heating current in the heating field 12 of the heatable coating 8 situated therebetween. The two collection lines 11, 11′ are, for example, printed on the electrically conductive coating 8 and have, in each case, an at least approx. rectilinear course.

[0148] The upper collection line 11 can be subdivided into two subregions separated from one another.

[0149] A first coating-free zone 14 with a zone edge 16 formed by the electrically conductive coating 8 is arranged below the upper collection line.

[0150] The additional electrode 15, 15′, 15″ completely surrounding the first coating-free zone 14 is galvanically coupled to the upper collection line 11 and the lower collection line 11′ via the heating field 12 of the electrically conductive coating 8.

[0151] Here, the coating-free zone 14 has, for example, an at least approx. rectangular contour. It is permeable, at least to a portion of the electromagnetic spectrum (e.g., IR radiation, radio waves in the ultrashort, short, and longwave range), in order to enable smooth data traffic through the windshield 1. The coating-free zone 14 can, for example, be produced by prior masking during the application of the electrically conductive coating 8 on the inner pane 3. Alternatively, it can also be produced after application of the electrically conductive coating 8 by chemical and/or mechanical removal, for example, by etching or using a friction wheel.

[0152] The upper collection line 11 and the lower collection line 11′ as well as the additional electrode 15, 15′, 15″ are produced by printing a metallic screenprinting paste, in particular a silver paste, using a screenprinting method, onto the electrically conductive coating 8, preferably in one process step.

[0153] Here, according to the invention, a bright silver paste with a silver content of 80 wt.-%, based on its total amount, is used for the production of the collection lines 11.

[0154] Here, according to the invention, a dark silver paste with a silver content of 65 wt.-%, based on its total amount, is used for the production of the additional electrode 15, 5′, 15″.

[0155] The resultant additional electrode 15,15′,15″ has 0.15 times the electrical conductivity of the collection lines 11, 11′.

[0156] The method according to the invention is performed such that the collection lines 11 and 11′ are completely covered by the masking strip 13 and the first coating-free zone 14 is only partially covered.

[0157] By means of the use according to the invention of silver pastes having different silver contents, the transparent pane according to the invention of FIG. 1 meets not only the requirements of the OEMs for electrical properties, in particular the suppression of hot spots on application of a supply voltage and with relatively long operation, but also the requirements for coloration.

[0158] FIG. 4 depicts a transparent windshield 1 of a motor vehicle viewed from the inside. Here again, the windshield 1 is implemented as a composite glass pane, whose structure is illustrated with reference to the representation of a vertical section through a detail of the windshield 1 in FIG. 2 and with reference to the perspective sectional representation of the detail of the windshield 1 in FIG. 3.

[0159] The transparent windshield 1 of FIG. 4 differs from the transparent windshield 1 of FIG. 1 only through the use of an additional electrode 15,15′,15″, which surrounds the coating-free zone 14, in sections only, for three-fourths of the length of the zone edge 16.

[0160] By means of the use according to the invention of silver pastes having different silver contents, the transparent pane according to the invention of FIG. 4 meets not only the requirements of the OEMs for electrical properties, in particular the suppression of hot spots on application of a supply voltage and with relatively long operation, but also the requirements for coloration.

[0161] FIG. 5 depicts a transparent windshield 1 of a motor vehicle viewed from the inside. Here again, the windshield 1 is implemented as a composite glass pane, whose structure is illustrated with reference to the representation of a vertical section through a detail of the windshield 1 in FIG. 2 and with reference to the perspective sectional representation of the detail of the windshield 1 in FIG. 3.

[0162] The transparent windshield 1 of FIG. 5 differs from the transparent windshield 1 of FIG. 1 only through the use of an additional electrode 15,15′,15″, which surrounds the coating-free zone 14, in sections only, or roughly half the length of the zone edge 16 as subregions 15, 15′ of the additional electrode. These two subregions 15,15′ are connected by a subregion 15″, that makes up roughly one-fourth of the length of the zone edge 16 and is routed, in sections, by the coating-free zone 14 along a section of the zone edge 16.

[0163] Through the use according to the invention of silver pastes having different silver contents, the transparent pane according to the invention of FIG. 5 meets not only the requirements of the OEMs for the electrical properties, in particular the suppression of hot spots on application of a supply voltage and with relatively long operation, but also the requirements for coloration.

[0164] FIG. 6 depicts a transparent windshield 1 of a motor vehicle viewed from the inside. Here again, the windshield 1 is implemented as a composite glass pane, whose structure is illustrated with reference to the representation of a vertical section through a detail of the windshield 1 in FIG. 2 and with reference to the perspective sectional representation of the detail of the windshield 1 in FIG. 3.

[0165] The transparent windshield 1 of FIG. 6 differs from the transparent windshield 1 of FIG. 1 only in that in addition to the coating-free zone 14 on its left and right and below the collection line 11, another coating-free zone 14′ and 14″ is arranged in each case, which zones are completely covered by the masking strips 13, 13′.

[0166] Through the use according to the invention of silver pastes having different silver contents, the transparent pane according to the invention of FIG. 6 not only meets the requirements of the OEMs for the electrical properties, in particular the suppression of hot spots on application of a supply voltage and with relatively long operation, but also the requirements for coloration.

[0167] Another aspect of the invention comprises a transparent pane (1) with at least one heatable, electrically conductive coating (8), which is connected to at least two collection lines (11, 11′) provided for the electrical connection to the two poles of a voltage source such that by application of a supply voltage, a heating current flows over a heating field (12) formed between the at least two collection lines, wherein the heating field (12) contains at least one coating-free zone (14), which is delimited by a zone edge (16) of the coating-free zone (14) formed, at least in sections, by the electrically conductive coating (8) and which is surrounded by at least one additional electrode (15, 15′, 15″), at least in sections, wherein [0168] the at least one additional electrode (15,15′, 15″) is electrically connected to the collection lines (11, 11′) via the heating field (12) of the coating (8), and [0169] the at least two collection lines (11, 11′) have a bright, silver color and the additional electrode has a dark color.

[0170] The invention further includes a transparent pane (1), wherein the at least two collection lines (11, 11′) have a higher silver content than the at least one additional electrode (15, 15′, 15″).

[0171] The invention further includes a transparent pane (1), wherein the electrical conductivity of the at least one additional electrode (15, 15′, 15″) is 0.05 to 0.3 times the electrical conductivity of the at least two collection lines (11, 11′).

[0172] The invention further relates to a transparent pane (20), wherein the at least two collection lines (11, 11′) have a bright, silver color with L*>65, preferably >80 and the at least one additional electrode (15, 15′, 15″) has a dark color with L*≦65, preferably <50.

[0173] Another aspect of the invention comprises a transparent pane (1) with at least one heatable, electrically conductive coaling (8), which is connected to at least two collection lines (11, 11′) provided for the electrical connection to the two poles of a voltage source such that by application of a supply voltage, a heating current flows over a heating field (12) formed between the at least two collection lines, wherein the heating field (12) contains at least one coating-free zone (14), which is delimited by a zone edge (16) of the coating-free zone (14) formed, at least in sections, by the conductive coating (8) and which is surrounded by at least one additional electrode (15, 15′, 15″), at least in sections, wherein [0174] the at least one additional electrode (15,15′, 15″) is electrically connected to the collection lines (11, 11′) via the heating field (12) of the coating (8), and [0175] the at least two collection lines (11, 11′) have a bright, silver color with L*>65, preferably >80 and the at least one additional electrode (15, 15′, 15″) has a dark color with L*≦65, preferably <50.