Method for producing a printed, coated panel

Abstract

A method for producing a coated and printed glass panel, includes a) providing a glass substrate having a metal-containing coating on a first surface and a polymeric protective layer with a thickness d arranged on this metal-containing coating, b) removing the polymeric protective layer in a first region using a carbon dioxide laser, c) removing the metal-containing coating within the first region only in a second region using a solid-state laser such that an edge region is created, in which the metal-containing coating is intact and in which the polymeric protective layer was removed in step b), d) applying a ceramic ink only in the first region, e) heat treating the glass panel at >600° C., wherein the polymeric protective layer is removed on the entire first surface, in the edge region, the metal-containing coating is dissolved by the ceramic ink lying above it, and the ceramic ink is fired.

Claims

1. A method for producing a coated and printed glass panel, comprising the steps of: a) providing a glass substrate having a metal-containing coating on at least one first surface and a polymeric protective layer with a thickness d arranged on said metal-containing coating, wherein the polymeric protective layer has a thickness d of 1 μm to 30 μm, b) reducing the thickness of the polymeric protective layer to a residual thickness in a first region using a carbon dioxide laser, c) removing the metal-containing coating only in a second region located within the first region using a solid-state laser such that an edge region within the first region is created in which the metal-containing coating is intact and in which the thickness of the polymeric protective layer was reduced to the residual thickness, d) applying a ceramic ink only in the first region, and e) performing a temperature treatment of the glass panel at >600° C., wherein the polymeric protective layer is removed on the entire first surface, and the ceramic ink in the edge region migrates into the metal-containing coating and bonds with the first surface of the glass panel.

2. The method according to claim 1, wherein in step d), the ceramic ink is applied in the edge region at a distance s of at least 0.5 mm from the remaining polymeric protective layer.

3. The method according to claim 1, wherein the polymeric protective layer is not water-soluble and is produced from a composition that contains meth(acrylates).

4. The method according to claim 1, wherein the glass panel is thermally toughened during the temperature treatment.

5. The method according to claim 4, wherein the thermally toughened glass panel is a single-pane safety glass or a partially toughened glass.

6. The method according to claim 1, wherein the ceramic ink is applied with a roll coater or a digital printer.

7. The method according to claim 1, wherein the first region is subjected to plasma cleaning before the application of the ceramic ink.

8. The method according to claim 1, wherein the region with the metal-containing coating and the polymeric protective layer has emissivity c greater than 40%.

9. The method according to claim 8, wherein the emissivity ε is greater than 45%.

10. The method according to claim 1, wherein the application of the ceramic ink is done in the first region under camera control, wherein the camera detects a difference between the de-coated second region and the region provided with the polymeric protective layer of the thickness d.

11. The method according to claim 1, wherein the glass panel is between 1 m.sup.2 and 54 m.sup.2 in size.

12. The method according to claim 11, wherein the glass panel is between 10 m.sup.2 and 30 m.sup.2 in size.

13. The method according to claim 1, wherein the first region extends along at least one edge of the glass panel and, measured from the panel edge, has a width b between 0.5 cm and 30 cm.

14. The method according to claim 13, wherein the width b is between 1 cm and 20 cm.

15. The method according to claim 1, wherein the metal-containing coating has an IR-reflecting function and contains at least two silver-containing layers as well as at least three dielectric layers.

16. A method comprising utilizing the glass panel produced in a method according to claim 1 as building glazing indoors or outdoors.

17. The method according to claim 1, wherein the thickness d is from 15 μm to 20 μm.

18. The method according to claim 1, wherein after step b), the residual thickness of the polymeric protective layer in the edge region is less than 0.5 μm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following, the invention is explained in detail with reference to drawings and exemplary embodiments. The drawings are schematic representations and not to scale. The drawings in no way restrict the invention.

(2) They depict:

(3) FIG. 1 a plan view of a glass panel produced in accordance with a method according to the invention,

(4) FIG. 2 a cross-section through a part of a glass panel produced in accordance with the method according to the invention,

(5) FIG. 3 a schematic representation of a method according to the invention,

(6) FIG. 4 a schematic representation of errors that can occur during the printing of glass panels, and

(7) FIG. 5 an enlarged representation of the region A of FIG. 3.

(8) FIG. 1 depicts a plan view of a glass panel 1 produced with the method according to the invention. FIG. 2 depicts a cross-section through a region of the glass panel 1. The glass panel 1 is depicted after the temperature treatment of the method according to the invention. The glass panel 1 is a 2 m×1 m glass panel with a thickness of 6 mm. The glass substrate 2 is a clear float glass, as is marketed, for example, by SAINT GOBAIN GLASS under the name PLANICLEAR®. A silver-containing IR-reflecting coating 4 is applied on the first surface 3.1 of the glass substrate. The coating 4 contains two functional silver layers that are arranged alternatingly with 3 dielectric layers. The total thickness of the metal-containing coating 4 is approx. 150 nm. A black ceramic ink 7 is fired in the first region. The first region 6 forms a frame around the glass panel 1 with a width b of 10 mm. The frame serves as a masking print behind which the fastening materials and the edge seal of the finished insulating glazing panel are hidden.

(9) FIG. 3 is a schematic representation of the method according to the invention. Step a) starts with a 6-mm-thick glass substrate 2 with a metal-containing coating 4 with a total thickness of 200-250 nm at least comprising three silver layers and four dielectric layers. The metal-containing coating 4 is covered by a 15-μm-thick polymeric protective layer 5. The polymeric protective layer 5 is produced from a composition that contains meth(acrylates) and was cross-linked under UV radiation. The polymeric protective layer 5 has a thickness d of 15 μm. A suitable polymeric protective layer 5 is offered by SAINT GOBAIN GLASS under the name EASYPRO®. The first surface 3.1 of the glass substrate 2 is provided over its entire surface with the layers 4 and 5. In step b), using a 2D laser scanner with a carbon dioxide laser, the polymeric protective layer 5 is removed in the first region 6 with the width b=20 mm to a remaining residual thickness of d.sub.Rand=0.5 μm. The region A surrounded by a broken line is enlarged for illustration in FIG. 5a. In step c), the second region 9 is de-coated with a 2D laser scanner with a solid-state laser. The metal-containing coating 4 and the residual thickness of 1 μm are removed in the entire second region 9. For this, the solid-state laser de-coats a smaller second region 9, which lies within the first region 6. The steps b) and c) take place under ambient conditions without exclusion of oxygen. After step c), the metal-containing coating and the polymeric protective layer are removed in the entire second region 9. In the edge region 10 with the width r=1 mm, the metal-containing coating 4 is still present as well as a remaining residue of the polymeric protective layer of the thickness d.sub.Rand of 0.5 μm. In the following step d), a black ceramic ink 7 is applied in the first region 6. Here, it is important for an optimum result that no overprinting of the polymeric protective layer 5 in the original thickness d=15 μm occurs. To ensure this, a safety distance s of 0.5 mm is left free. FIG. 5b) depicts this schematically for the same detail as in FIG. 5a). In the last step e), the panel 1 is subjected to a temperature treatment at 690° C. for 8 minutes. Here, simultaneously, the panel is toughened, the polymeric protective layer 5 is removed without residue, and the ceramic ink 7 dissolves the remaining metal-containing ink in the edge region and bonds with the glass surface.

(10) FIG. 4 depicts two error patterns that can develop as a result of incorrect alignment of the print when the method according to the invention is not used. In Fig. a), the print is not positioned exactly adjacent the metal-containing coating such that a bright line develops along the print that disrupts the optical appearance of the product. In Fig. b), the print is positioned partially overlapping the metal-containing coating 4, likewise resulting in optical defects. As a result of the partial overprinting of the metal-containing coating 4 in the edge region 10, such error patterns can be prevented with the method according to the invention.

(11) In the following, the advantages of the method according to the invention (Example) are explained in comparison with a prior art method (Comparative Example).

(12) In both cases, a 1 m×2 m glass substrate of clear float glass was produced with the same silver-containing coating comprising 3 functional silver layers. A black edge printing in the shape of a frame was applied with different widths b. After printing, the panels were toughened at a temperature of 690° C. for a period of 500 seconds. The thermal emissivity was determined using an INGLAS TIR100-2.

EXAMPLE

(13) Glass panel: 1 m×2 m clear float gas

(14) Metal-containing coating: contains 3 silver layers

(15) Polymeric protective layer: 15 μm SGG EasyPro®; (meth)acrylate-based layer

(16) Emissivity of the unprinted region (metal-containing coating and polymeric protective layer; measured before the temperature treatment): 45%

(17) Emissivity of the printed region (measured after the temperature treatment): 89%

COMPARATIVE EXAMPLE

(18) Glass panel: 2 m×1 m clear float glass

(19) Metal-containing coating: contains 3 silver layers

(20) Emissivity of the unprinted region (only metal-containing coating; measured before the temperature treatment): 2%

(21) Emissivity of the printed region (measured after the temperature treatment): 89%

(22) TABLE-US-00001 Deformation in mm measured at a distance of 5 mm from the edge of the glass panel Example Comparative Example Width b of the (with polymeric (without polymeric frame in mm protective layer) protective layer) 24 None 0.10 96 0.05 0.15 192 0.10 Glass breakage

(23) The deformation was measured as a change in thickness of the glass panel at a distance of 5 mm from the edge. The comparison shows that the method according to the invention results in substantially less or no deformation at all in the printed region. In the case of larger frame prints, there was even glass breakage without the use of a protective layer.

LIST OF REFERENCE CHARACTERS

(24) 1 glass panel 2 glass substrate 3.1 first surface of the glass substrate 3.2 second surface of the glass substrate 4 metal-containing coating 5 polymeric protective layer, temporary protective layer 6 first region, region to be printed, printed region 7 ceramic ink 9 second region 10 edge region 12 a panel edge b width of the first region d thickness of the polymeric protective layer at the beginning of the method d.sub.Rand thickness of the polymeric protective layer in the edge region after step b) r width of the edge region s distance between the ceramic ink and the polymeric protective layer