Abstract
A method for producing a composite pane is presented. A first laminating film is placed on an electrically conductive coating of a carrier film, and the carrier film and the first laminating film are then joined to form a bilayer. The bilayer is arranged on an outer pane such that the first laminating film lies areally on the outer pane, and a second laminating film is arranged on the bilayer such that the second laminating film lies areally on the carrier film. An inner pane is placed on the second laminating film, and a composite pane is formed by autoaclaving a layered stack formed by the panes, films and coatings.
Claims
1.-13. (canceled)
14. A method for producing a composite pane, the method comprising the following steps: a) providing a carrier film having an infrared-reflecting coating; b) placing a first laminating film on the infrared-reflecting coating of the carrier film; c) joining the carrier film and the first laminating film to form a bilayer ; d) arranging the bilayer on one of an outer pane and an inner pane so that the first laminating film lies areally on the one of the outer pane and the inner pane, and arranging a second laminating film on the bilayer so that the second laminating film lies areally on the carrier film; e) placing the other of the outer pane and the inner pane on the second laminating film; f) based on the steps a)-e), autoclaving a layered stack to form a composite pane that comprises i) the outer pane; ii) the bilayer made of the first laminating film and the carrier film having an infrared-reflecting coating; iii) the second laminating film; and iv) the inner pane.
15. The method according to claim 14, wherein the carrier film and the first laminating film are joined in step c) under pressure at a temperature of 40? C. to 80? C. to form bilayer.
16. The method according to claim 14, wherein step c) further comprises: unrolling the carrier film and the first laminating film from a respective roll; forming the bilayer; and rolling the bilayer onto a roll.
17. The method according to cliam 14, wherein step d) further comprises: before the arranging of the second laminating film, removing, in at least one edge region of the composite pane, the carrier film having the infrared-reflecting coating.
18. The method according to claim 14, wherein step d) further comprises: before the arranging of the second laminating film, removing, in a region of at least one sensor window of the composite pane, the carrier film having the infrared-reflecting coating.
19. The method according to claim 14, further comprising, between step c) and step d): inserting at least two busbars into the bilayer so that the at least two busbars electrically conductingly contact the infrared-reflecting coating; and using an electrically conducting coating as the infrared-reflecting coating.
20. The method according to claim 14, wherein the infrared-reflecting coating is applied on the carrier film before step a) by physical vapor deposition.
21. The method according to claim 14, wherein the infrared-reflecting coating contains at least one of: a) silver and and b) an electrically conductive oxide.
22. The method according to claim 14, wherein the first laminating film and the second laminating film contain at least one of: a) polyvinyl butyral (PVB), b) ethylene vinyl acetate (EVA), c) polyurethane (PU), d) mixtures of one or more of a)-c), e) copolymers of one or more of a)-c), and f) derivatives of one or more of a)-c).
23. The method according to claim 14, wherein the first laminating film and the second laminating film have a respective thickness of 0.2 mm to 2.0 mm, preferably of 0.3 mm to 1.0 mm.
24. The method according to claim 14, wherein the first laminating film and the second laminating film have a respective thickness of 0.3 mm to 1.0 mm.
25. The method according to claim 14, wherein the carrier film contains at least one of: a) polyethylene terephthalate (PET), b) polyethylene (PE), c) mixtures of one or more of a) and b), d) copolymers of one or more of a) and b), and e) derivatives of one or more of a) or b).
26. The method according to claim 14, wherein the carrier film has a thickness of 5 ?m to 500 ?m, preferably 10 ?m to 200 ?m.
27. The method according to claim 14, wherein the carrier film has a thickness of 10 ?m to 200 ?m.
28. A composite pane, comprising: an outer pane; a bilayer made of a first laminating film and a carrier film having an infrared reflecting coating; a second laminating film; and an inner pane.
Description
[0060] The invention is described in detail in the following with reference to drawings and exemplary embodiments. The drawings are purely schematic representations and not true to scale. The drawings in no way restrict the invention.
[0061] They depict:
[0062] FIG. 1a and 1b a cross-section of a composite pane according to the invention without a heating function,
[0063] FIG. 2a a cross-section of a composite pane according to the invention with a heating function,
[0064] FIG. 2b a plan view of the composite pane according to the invention of FIG. 2a,
[0065] FIG. 3a flowchart of a method according to the invention,
[0066] FIG. 4a flowchart of a method not according to the invention as a comparative example
[0067] FIG. 1a and 1b depict a cross-section of a composite pane according to the invention 1, here, in an embodiment without a heating function. The composite pane 1 was produced by the method according to the invention described in FIG. 3. The composite pane consists of an outer pane 2 made of soda lime glass with a thickness of 2.1 mm, an intermediate layer 8, and an inner pane 3 made of soda lime glass with a thickness of 1.6 mm. The intermediate layer 8 in turn consists of a bilayer 7 and a second laminating film 4.2. The bilayer 7 is placed on the inner side II of an outer pane 2. The bilayer 7 consists of a first laminating film 4.1 and a carrier film 5 having an infrared-reflecting coating 6, wherein the infrared-reflecting coating 6 lies between the first laminating film 4.1 and the carrier film 5. The bilayer 7 is placed on the outer pane 2 such that the first laminating film 4.1 is areally arranged on the inner side II. The second laminating film 4.2 is areally placed on the carrier film 5 of the bilayer 7. The layer stack ends with an inner pane 3, whose inner side III lies areally on the second laminating film 4.2. After installation of the composite pane 1 in a vehicle, the outer side IV of the inner pane 3 is turned toward the vehicle interior, whereas the outer side I of the outer pane 2 points toward the external environment. The laminating films 4.1, 4.2 are formed, in each case, from a film with a thickness of 0.38 mm. The carrier film 5 is made of a PET film with a thickness of 50 ?m, on which a silver-containing coating is applied as an infrared-reflecting coating 6. The infrared-reflecting coating 6 could also be used as a heating layer, since it has adequately high conductivity. However, in this embodiment, it is used only to shield against undesirable thermal radiation. In the edge region A of the composite pane, the carrier film 5 having an infrared-reflecting coating 6 is cut back by an amount x, which defines the distance from the peripheral edge of the composite pane 1, wherein x varies between at least 10 mm at the A-pillars and a maximum of 300 mm at the engine edge. In this edge region A, the carrier film 5 and the infrared-reflecting coating 6 are completely removed. In another region B, the carrier film 5 having an infrared-reflecting coating 6 is removed, since this region is provided for the installation of a sensor behind the composite pane 1 in the interior of the vehicle. In the beam path of the sensor, the infrared-reflecting coating 6 must be removed to ensure unimpeded beam passage and to enable the unrestricted functioning of the sensor. In this region as well, the carrier film 5 is cut out. FIG. 1a depicts the arrangement before lamination, wherein the regions A, B, in which the carrier film 5 is removed, are readily discernible. In these regions A, B, the laminating films 4.1, 4.2 lie directly on one another. FIG. 1b depicts the arrangement of FIG. 1a after lamination of the layer stack to form a composite pane 1. In the edge region A and in the region B of the sensor window, the laminating films 4.1, 4.2 are fused to one another. The laminating films 4.1, 4.2 completely surround the carrier film 5 with coating 6 such that corrosion of the infrared-reflecting coating 6 by environmental influences, such as moisture, can be precluded.
[0068] FIG. 2a depicts a cross-section of a composite pane 1 of FIG. 1b, which, in addition to the features described there, has means for heating the composite pane 1. FIG. 2b depicts a plan view of the composite pane 1 of FIG. 2a, wherein the section line C-C, along which the cross-section of FIG. 2a runs, is indicated. Between the first laminating film 4.1 and the infrared-reflecting coating 6, at two opposite longitudinal edges of the composite panel, busbars 9 in foil form, which electrically conductingly contact the infrared-reflecting coating 6, are inserted into the layer composite. Via connection elements 10, an electric voltage can be applied to the busbars 9, as a result of which a current flows through the infrared-reflecting coating 6 and the composite pane 1 is heated.
[0069] FIG. 3 depicts a flowchart of a preferred embodiment of the method according to the invention for producing a composite panel. The composite pane described in FIGS. 1a and 1b was produced using the method of FIG. 3. The method steps depicted in FIG. 3 are as follows: [0070] I Providing a carrier film 5 with an infrared-reflecting coating 6 [0071] II Placing a first laminating film 4.1 on the infrared-reflecting coating 6 of the carrier film 5 [0072] III Joining the carrier film 5 and the first laminating film 4.1 to form a bilayer 7, wherein the carrier film 5 and the first laminating film 4.1 run through a heated roller pair with a temperature of 55? C. and are pressed together to form a bilayer 7 [0073] IV Trimming the bilayer 7 according to the size of the the outer pane 2, wherein the outline of the trimmed bilayer 7 corresponds to the outline of the outer pane 2 [0074] V Optional: cutting back the carrier film 5 having an infrared-reflecting coating 6 in the edge region A by an amount x and, to the extent required, in the region B of at least one sensor window [0075] VI Arranging the bilayer 7 on an outer pane 2, wherein the first laminating film 4.1 lies areally in the inner side II of the outer pane 2 and completely covers it [0076] VII Providing a second laminating film 4.2 corresponding to the size of the outer pane 2, wherein the outline of the trimmed second laminating film 4.2 corresponds to the outline of the outer pane 2 [0077] VIII Arranging the second laminating film 4.2 on the bilayer 7, wherein the second laminating film 4.2 lies areally on the carrier film 5 and completely covers it [0078] IX Placing an inner pane 3 on the second laminating film 4.2, wherein the inner side III of the inner pane 3 lies areally on the second laminating film 4.2 and completely covers it [0079] X Laminating the layer stack in the autoclave to form a composite pane 1
[0080] Using the method according to the invention described in FIG. 3, 70 windshields were produced with the structure described in FIG. 1b. Then, a visual inspection for defects of the infrared-reflecting coating 6 was performed. The number of the panes with defects was 0 (0%). The method according to the invention is thus particularly advantageous in terms of economical and defect-free production with a low rejection rate. Since the infrared-reflecting coating 6 is covered at a very early stage in the production process (already in step II) by the first laminating film 4.1, it is protected in the subsequent production process against damage and environmental influences and defects of the coating can be avoided.
[0081] FIG. 4 depicts a flowchart of a method not according to the invention as a comparative example. The steps of the method not according to the invention of FIG. 4 are: [0082] IA Providing a carrier film 5 with an infrared-reflecting coating 6 [0083] IIA Placing a second laminating film 4.2 on the uncoated surface of the carrier film 5, wherein a layer stack consisting of (in this order) the second laminating film 4.2, the carrier film 5, and the infrared-reflecting coating 6 is created [0084] IIIA Joining the carrier film 5 and the second laminating film 4.2 to form a bilayer 7A, wherein the carrier film 5 and the first laminating film 4.1 run through a heated roller pair with a temperature of 55? C. and are pressed together to form a bilayer 7A [0085] IVA Trimming the bilayer 7A corresponding to the size of the the outer pane 2, wherein the outline of the trimmed bilayer 7A corresponds to the outline of the outer pane 2 [0086] VA Optional: Cutting back the carrier film 5 having an infrared-reflecting coating 6 in the edge region A by an amount x and, to the extent required, in the region B of at least one sensor window [0087] VIA Providing a first laminating film 4.1 corresponding to the size of the outer pane 2, wherein the outline of the trimmed first laminating film 4.1 corresponds to the outline of the outer pane 2 [0088] VIIA Arranging the first laminating film 4.1 on an outer pane 2, wherein the first laminating film 4.1 lies areally on the inner side II of the outer pane 2 and completely covers it [0089] VIIIA Arranging the bilayer 7A on the first laminating film 4.1, wherein the infrared-reflecting coating 6 of the carrier film 5 lies areally on the first laminating film 4.1 [0090] IXA Placing an inner pane 3 on the bilayer 7A, wherein the inner side III of the inner pane 3 lies areally in the second laminating film 4.2 and completely covers it [0091] XA Laminating the layer stack in the autoclave to form a composite pane 1
[0092] The infrared-reflecting coating 6 thus lies exposed after step IIA of the method and is not covered until in step VIIIA by placement of the first laminating film 4.2 on the infrared-reflecting coating of the carrier film 5. Using the method described in FIG. 4, 70 windshields were produced. The basic structure corresponds to the structure described in FIG. 1b, wherein the configuration of the bilayer differs as described in FIG. 4. Then, a visual inspection for defects of the infrared-reflecting coating 6 was performed. The number of panes with defects was 24 (approx. 34%), with 9 panes (approx. 13%) having such serious defects that they had to be discarded.
List of Reference Characters:
[0093] 1 composite pane [0094] 2 outer pane [0095] 3 inner pane [0096] 4 laminating films [0097] 4.1 first laminating film [0098] 4.2 second laminating film [0099] 5 carrier film [0100] 6 infrared-reflecting coating [0101] 7 bilayer [0102] 8 intermediate layer [0103] 9 busbar [0104] 10 electrical connection element [0105] 11 screenprint [0106] A edge region with cutback of the carrier film 5 [0107] B region without carrier film 5 for sensor window [0108] x cutback of the carrier film 5 at a distance x from the peripheral edge of the composite pane 1 [0109] C-C section line [0110] I outer side of the outer pane [0111] II inner side of the outer pane [0112] III inner side of the inner pane [0113] IV outer side of the inner pane
