LAMINATED GLASS PANEL WITH THIN SHEET OF SHATTERPROOF GLASS

Abstract

A laminated glazing unit includes one to ten first glass sheets each of thickness included between 1.5 and 22 mm, if needs be adhesively bonded to one another by one or more first adhesive interlayers, and a second glass sheet forming one of the two faces of the laminated glazing unit, of thickness included between 0.5 and 1.5 mm, and adhesively bonded to the first glass sheet(s) by a second adhesive interlayer, the second glass sheet being made of aluminosilicate or soda-lime glass that is chemically toughened, having a surface stress comprised between 300 and 1000 and between 200 and 500 MPa, respectively, and a depth under compression between 20 and 100 μm.

Claims

1. A laminated glazing unit comprising one to ten first glass sheets each of thickness comprised between 1.5 and 22 mm, if needs be adhesively bonded to one another by one or more first adhesive interlayers, and a second glass sheet forming one of the two faces of the laminated glazing unit, of thickness comprised between 0.5 and 1.5 mm, and adhesively bonded to said first glass sheet(s) by a second adhesive interlayer, wherein said second glass sheet is made of aluminosilicate or soda-lime glass that is chemically toughened, having a surface stress comprised between 300 and 1000 and between 200 and 500 MPa, respectively, and a depth under compression between 20 and 100 μm in both cases.

2. The laminated glazing unit as claimed in claim 1, wherein said adhesive interlayers are chosen from polyvinyl butyral, thermoplastic polyurethane, ethylene vinyl acetate or an ionomer resin.

3. The laminated glazing unit as claimed in claim 1, wherein said second adhesive interlayer has a thickness comprised between 0.3 and 7.

4. The laminated glazing unit as claimed in claim 1, comprising a single said first glass sheet of thickness at most equal to 12 made of aluminosilicate or soda-lime or thermally tempered soda-lime glass that is chemically toughened, having a surface stress comprised between 300 and 1000 MPa for the aluminosilicate and 200 and 500 MPa for the soda-lime, respectively, and a depth under compression between 20 and 100 μm in both cases.

5. The laminated glazing unit as claimed in claim 1, comprising at least two said first glass sheets that are made, independently of each other, either of chemically toughened or thermally tempered soda-lime glass having a surface stress comprised between 200 and 500 MPa and a depth under compression between 20 and 100 μm, or of optionally chemically toughened aluminosilicate glass having a surface stress comprised between 300 and 1000 MPa and a depth under compression between 20 and 100 μm.

6. The laminated glazing unit as claimed in claim 5, comprising at most four, said first glass sheets.

7. The laminated glazing unit as claimed in claim 5, wherein the thickness of said first glass sheets is at most equal to 12 mm.

8. The laminated glazing unit as claimed in claim 5, wherein said first adhesive interlayer(s) has(have) a thickness (thicknesses) comprised between 0.7 and 8.

9. The laminated glazing unit as claimed in claim 1, wherein a face oriented toward said second glass sheet of one at least of said two first glass sheets that are furthest from said second glass sheet bears a heating layer.

10. A method comprising utilizing a laminated glazing unit as claimed in claim 1 for protection against an impact on a side of the laminated glazing unit which is opposite to the second-glass sheet so that projecting vulnerant splinters are not produced on the second-glass-sheet side during said impact.

11. A method comprising utilizing a laminated glazing unit as claimed in claim 1 for preventing the formation of smoke on a side of the second-glass sheet during a fire on that side of the laminated glazing unit.

12. The method as claimed in claim 10, wherein the laminated glazing unit is utilized as a water, air or land transport vehicle glazing unit, the face of which formed from said second glass sheet is the face that is oriented toward the interior of the vehicle.

13. The method as claimed in claim 12, wherein the laminated glazing unit is utilized as an aeronautical glazing unit or a train windshield.

14. The method as claimed in claim 10, wherein the laminated glazing unit is utilized as an architectural glazing unit, the face of which formed from said second glass sheet is the face that is oriented toward the interior of the building.

15. The laminated glazing unit as claimed in claim 3, wherein said second adhesive interlayer has a thickness at least equal to 1.25 mm.

16. The laminated glazing unit as claimed in claim 15, wherein the thickness is at most equal to 6 mm.

17. The laminated glazing unit as claimed in claim 16, wherein the thickness is at most equal to 5 mm.

18. The laminated glazing unit as claimed in claim 4, wherein said single first glass sheet has a thickness at most equal to 10 nm.

19. The laminated glazing unit as claimed in claim 6, comprising at most three said first glass sheets.

20. The laminated glazing unit as claimed in claim 8, wherein said first adhesive interlayer(s) has(have) a thickness (thicknesses) at least equal to 1 mm and at most equal to 7 mm.

Description

EXAMPLE 1

[0026] A laminated glazing unit is formed from a sheet of soda-lime-silica float glass that is chemically toughened in the sense defined above (i.e. having a surface stress comprised between 200 and 500 MPa and a depth under compression between 20 and 100 μm) of 3 mm thickness and from another sheet of the same chemically toughened material but of 0.8 mm thickness, which sheets are adhesively bonded to each other by a 2 to 5 mm-thick layer of polyvinyl butyral (PVB) or thermoplastic polyurethane (TPU).

[0027] That face of the 3 mm-thick chemically toughened glass sheet which is oriented toward the other glass sheet is coated with a 200 nm-thick layer of indium tin oxide (ITO).

[0028] An impact on that face of the glazing unit which is formed from the thickest glass sheet does not produce vulnerant splinters on the side of the other face of the glazing unit. The products of the breakage of the thin glass sheet remain adhesively bonded to the adhesive interlayer.

EXAMPLE 2

[0029] In the following examples the following abbreviations will be used:

[0030] RC: soda-lime-silica float glass (or optionally aluminosilicate glass for thicknesses at most equal to 3 mm) that is chemically toughened in the sense defined above (especially two different surface stress domains in the two cases);

[0031] V: soda-lime-silica float glass that is not chemically toughened and optionally thermally tempered, or aluminosilicate glass that is not chemically toughened for thicknesses at most equal to 3 mm;

[0032] PU: polyurethane; and

[0033] PVB: polyvinyl butyral.

[0034] The following laminated glazing unit was assembled; the thickness of the constituents thereof is indicated below in millimeters:

[0035] 6RC/5PU/3RC/2.8PU/0.8RC

[0036] In this example and in the following ones, a UIC projectile according to standard EN 15152:2007 (F) was fired horizontally at a specified speed at the glazing unit, which was inclined at a specified angle to the horizontal.

[0037] In this example, the maximum speed of the train was lower than or equal to 160 km/h and the glazing unit was inclined at 75° to the horizontal.

EXAMPLE 3

[0038] The composition of the laminated glazing unit was:

[0039] 6RC/1.14PVB/3RC/4.56PU/3RC/3.3PU/0.8RC The maximum speed of the train was above 160 km/h and lower than or equal to 300 km/h and the glazing unit was inclined at 40° to the horizontal.

EXAMPLE 4

[0040] The composition of the laminated glazing unit was:

[0041] 8RC/1.9PVB/6V/1.52PVB/6RC/2PU/0.8RC

[0042] The maximum speed of the train was above 300 km/h and the glazing unit was inclined at 30° to the horizontal.

[0043] In examples 2 to 4 the adhesive interlayer adhesively bonding the thin glass was observed to pocket the projectile, which did not perforate it. The splinters of the thin glass sheet remained adhered to this adhesive interlayer (PU). No vulnerant glass splinters originating from breakage of the 0.8 mm-thick sheet were projected.

[0044] The 0.8 mm-thick glass sheet may be given a complex shape and especially a double (spherical) curvature. Its material is qualified fire safe, in contrast to organic polymer materials.