LAMINATED GLAZING

Abstract

A bent laminated glazing, in particular for a motor vehicle windscreen, includes a first glass sheet adhesively bonded to a second glass sheet by a lamination interlayer, the first glass sheet including a face, referred to as face 2, facing the lamination interlayer, and the second glass sheet including a face, referred to as face 4, opposite the lamination interlayer, wherein the face 2 includes a region, referred to as first region, coated with a layer of opaque mineral paint obtained from an aqueous paint composition including pigments and an aqueous solution of alkali metal silicate, and the face 4 includes a region, referred to as second region, coated with an enamel coating.

Claims

1. A bent laminated glazing comprising a first glass sheet adhesively bonded to a second glass sheet by a lamination interlayer, said first glass sheet comprising a face facing said lamination interlayer, and said second glass sheet comprising a face opposite said lamination interlayer, wherein said face of the first glass sheet comprises a first region, coated with a layer of opaque mineral paint obtained from an aqueous paint composition comprising pigments and an aqueous solution of alkali metal silicate, and said face of the second glass sheet comprises a region second region, coated with an enamel coating.

2. The bent laminated glazing according to claim 1, wherein the layer of opaque mineral paint is black.

3. The bent laminated glazing according to claim 1, wherein the first region represents between 2 and 25% of a surface area of the face of the first glass sheet.

4. The bent laminated glazing according to claim 1, wherein a thickness of the layer of mineral paint is between 2 and 20 μm.

5. The bent laminated glazing according to claim 1, wherein the second region represents between 1 and 15% of a surface area of the face of the second glass sheet.

6. The bent laminated glazing according to claim 1, wherein the second region is in the form of a peripheral strip.

7. The bent laminated glazing according to claim 1, wherein the second region is facing at least part of the first region.

8. The bent laminated glazing according to claim 1, wherein, in the layer of mineral paint, a content by weight of alkali metal silicate is between 7% and 60% and a total content by weight of pigments and mineral fillers is between 20 and 90%.

9. The bent laminated glazing according to claim 8, wherein, in the layer of mineral paint, the content by weight of alkali metal silicate is between 15% and 55% and the total content by weight of pigments and mineral fillers is between 30 and 70%.

10. A method for obtaining a laminated glazing according to claim 1, comprising: depositing on the first region, of the face of the first glass sheet, the aqueous paint composition comprising pigments and the aqueous solution of alkali metal silicate, then pre-curing at a temperature of at least 200° C., so as to obtain the layer of opaque mineral paint, depositing on the second region, of the face of the second glass sheet, the enamel coating, then bending the first and second glass sheet, then laminating the first and the second glass sheet by the lamination interlayer, such that said face of the first glass sheet is facing said interlayer and said face of the second glass sheet is opposite said interlayer.

11. The method according to claim 10, wherein the depositing of the aqueous paint composition is carried out by screen printing.

12. The method according to claim 10, wherein the pre-curing is carried out at a temperature of at most 580° C.

13. A motor vehicle windscreen comprising a glazing according to claim 1, wherein the layer of opaque mineral paint creates a camera region, said motor vehicle windscreen further comprising at least one sensor arranged facing said camera region and also an assembly seal arranged in contact with the enamel coating.

14. The motor vehicle windscreen according to claim 13, wherein the first glass sheet corresponds to an external sheet of the windscreen, arranged on a convex side and intended to be positioned outside the vehicle, and the second glass sheet corresponds to an internal sheet of the windscreen, arranged on a concave side and intended to be positioned inside the vehicle.

15. The motor vehicle windscreen according to claim 13, wherein a surface area of the camera region is between 5 and 300 cm.sup.2.

16. The bent laminated glazing according to claim 1, wherein the bent laminated glazing is a motor vehicle windscreen.

17. The bent laminated glazing according to claim 2, wherein a lightness L* measured in reflection on a glass side of the first glass sheet opposite the first region is less than 5.

18. The bent laminated glazing according to claim 3, wherein the first region represents between 3 and 20% of the surface area of the face of the first glass sheet.

19. The bent laminated glazing according to claim 4, wherein the thickness of the layer of mineral paint is between 3 and 15 μm.

20. The bent laminated glazing according to claim 5, wherein the second region represents between 2 and 10% of the surface area of the face of the second glass sheet.

Description

[0070] FIG. 1 and the examples which follow non limitingly illustrate the invention.

[0071] [FIG. 1] is an exploded view of the two glass sheets of a nonlimiting example of laminated glazing according to the invention.

[0072] The first glass sheet 1 and the second glass sheet 2 are herein shown after bending and before lamination. After lamination, the assembly will form a motor vehicle windscreen. The face 1 of what will become the laminated glazing (face intended to be positioned outside the motor vehicle) is shown at the front of the first glass sheet 1. The face 2, denoted 12, is therefore the rear face of the first glass sheet 1, and after lamination will be in contact with the lamination interlayer, not shown.

[0073] The face 4, denoted 22, of what will become the laminated glazing (face intended to be positioned inside the motor vehicle) is also the rear face of the second glass sheet 2.

[0074] The face 2, denoted 12 in the figure, is coated with a layer of opaque black mineral paint based on silicate in a first region 14. It has the form of a relatively narrow peripheral strip on the lateral edges, which is wider in the lower part, and also forms, in the upper central part, a region intended to conceal and protect the seal for attaching the interior rear-view mirror. The layer of mineral paint further forms an uncoated camera region 16 which is trapezoidal in shape.

[0075] The face 4, denoted 22 in the figure, is coated with an enamel coating in a second region 24. It is in the form of a peripheral strip which occupies part of the periphery of the second glass sheet 2. The peripheral strip is thin, with dimensions based on the width of the seal which will be deposited on the enamel coating and will serve to attach the glazing to the vehicle body window opening. According to another example, the peripheral strip may be wider than the width of the seal and therefore be visible from inside the vehicle. The second region 24 is located facing the first region 14.

[0076] The layer of mineral paint and the enamel coating are visible here by transparency through the glass sheets 1 and 2 since they are deposited on the faces shown “behind” the glass sheets in the figure.

[0077] Glazings as shown in the figure were obtained in the manner described below.

[0078] A layer of black opaque mineral paint was deposited on a first clear glass sheet of a thickness of 2.1 mm. The layer was deposited by screen printing, using a screen having 77 threads/cm, a silicate composition sold under the reference Ceramiglass OPH-CG21-231 by ICD. The layer then underwent pre-curing at 560° C.

[0079] A coating of black enamel, sold under the reference 14305 by Ferro, was deposited by screen printing on a second clear glass sheet of a thickness of 2.1 mm.

[0080] The two glass sheets were then bent together by gravity, according to a known process, the second glass sheet being located above the first glass sheet.

[0081] In a comparative example C1, the layer of silicate paint on face 2 was replaced with a layer of enamel (reference JM 1L6026), deposited by screen printing using a screen having 90 threads/cm.

[0082] In a comparative test C2, the enamel coating on face 4 was replaced by a layer of silicate paint identical to that deposited on face 2.

[0083] The optical distortion (29.4°, filter 1/2/0) in the camera region in the case of the example according to the invention was 80 millidiopters. For the comparative example C1, it was 180 millidiopters.

[0084] The chemical resistance of the coating deposited on face 4 was evaluated by acid attack by means of a 0.1 N solution of sulfuric acid at 80° C. for durations ranging from 4 to 78 h. No discoloration was observed for the example according to the invention. On the other hand, significant discoloration was observed in the case of the comparative example C2 for attack durations of greater than 4 h.