Coloured laminated glass

Abstract

A decorative laminated glass includes a first glass sheet, a second glass sheet, and a colored lamination interlayer between the first glass sheet and the second glass sheet. A coating is positioned between the first glass sheet and the lamination interlayer, and in direct contact with the first glass sheet. The coating is formed by the series of the following layers, starting from the surface of the first glass sheet: optionally, a first stack of dielectric layers; a layer based on titanium oxide having a thickness of from 5 to 70 nm; and optionally, a second stack of dielectric layers.

Claims

1. A laminated glass comprising: a first glass sheet, a second glass sheet, and a colored lamination interlayer between the first glass sheet and the second glass sheet, wherein a coating is positioned between the first glass sheet and the lamination interlayer, and in direct contact with the first glass sheet, said coating comprising the following layers, starting from a surface of the first glass sheet: a first stack of one or more dielectric layers, wherein the overall optical thickness of the first stack of dielectric layers is from 20 to 120 nm; a layer based on titanium oxide having a physical thickness of from 5 to 70 nm; and a second stack of one or more dielectric layers, wherein the overall optical thickness of the second stack of dielectric layers is from 5 to 50 nm, wherein the layer based on titanium dioxide is between the first and second stacks of dielectric layers.

2. The laminated glass as claimed in claim 1, wherein the second glass sheet is in direct contact with the lamination interlayer.

3. The laminated glass as claimed in claim 1, wherein the physical thickness of the layer based on titanium oxide is from 20 to 50 nm.

4. The laminated glass as claimed in claim 1, wherein said layer based on titanium oxide comprises silicon.

5. The laminated glass as claimed in claim 4, wherein a Si/Ti overall atomic ratio in said titanium-based layer is from 0.01 to 0.25.

6. The laminated glass as claimed in claim 4, wherein, in the layer based on titanium oxide, the atoms of silicon and of titanium represent at least 90% of the atoms other than oxygen.

7. The laminated glass as claimed in claim 1, wherein the first stack of dielectric layers and the second stack of dielectric layers are formed of one or more dielectric layers independently selected from the group consisting of layers based on oxides of zinc, silicon, tin, titanium, zirconium, niobium and of mixtures thereof, layers based on nitrides of silicon and/or of aluminum, and layers based on oxynitrides of silicon and/or of aluminum.

8. The laminated glass as claimed in claim 1, wherein the first stack of dielectric layers is formed of two dielectric layers, the first layer being based on silicon oxide and the second layer being based on silicon nitride.

9. The laminated glass as claimed in claim 1, wherein the first stack of dielectric layers is formed of a single layer based on silicon nitride or on silicon oxide.

10. The laminated glass as claimed in claim 1, wherein the second stack of dielectric layers is formed of two layers, the first layer being based on silicon oxide and the second layer being based on titanium oxide.

11. The laminated glass as claimed in claim 1, wherein an antireflection coating is positioned on the outer face of the second glass sheet.

12. An article comprising: the laminated glass as claimed in claim 1, said article being chosen from office partitions, wall coverings, credenzas, doors, balustrades, facade glazing, privacy screens and brise soleils.

13. A process for manufacturing a laminated glass as claimed in claim 1, comprising: providing a first glass sheet coated with a coating in direct contact with the first glass sheet, said coating comprising a series of the following layers, starting from the surface of the glass: a first stack of one or more dielectric layers, wherein the overall optical thickness of the first stack of dielectric layers is from 20 to 120 nm; a layer based on titanium oxide having a physical thickness of from 5 to 70 nm; and a second stack of one or more dielectric layers, wherein the overall optical thickness of the second stack of dielectric layers is from 5 to 50 nm, wherein the layer based on titanium dioxide is between the first and second stacks of dielectric layers; positioning, with regard to the first glass sheet, a lamination interlayer and a second glass sheet, so as to have the coating in contact with the lamination interlayer and the lamination interlayer in contact with the second glass sheet to form a laminated structure; and heating the laminated structure at a temperature above the glass transition temperature of the lamination interlayer to form the laminated glass.

Description

EXAMPLE 1

(1) A decorative laminated glass I1 according to the invention, as illustrated in FIG. 1, was prepared from 4 mm thick PLANICLEAR glass sheets sold by the Applicant. A coating formed of a glass/Si.sub.3N.sub.4 (30 nm)/TiO.sub.2 (22 nm)/SiO.sub.2 (7 nm)/TiO.sub.2 (1 nm) stack was deposited by magnetron sputtering on the inner surface of the first glass sheet. The thicknesses indicated between parentheses correspond to the physical thicknesses. The coated first glass sheet was then laminated with the uncoated second glass sheet with the aid of a Vanceva® True Blue colored PVB lamination intermediary by positioning the coated face of the first glass sheet in contact with the lamination intermediary.

(2) A laminated glass I2 according to the invention was prepared in the same way as the glass I1 except that the second glass sheet has a glass/Si.sub.3N.sub.4 (18 nm)/SiO.sub.2 (28 nm)/Si.sub.3N.sub.4 (102 nm)/SiO.sub.2 (90 nm) antireflection coating on its outer surface.

(3) In comparison, a laminated glass C1 was prepared in an identical manner to the laminated glasses I1 and I2, except that none of the first and second glass sheets has a coating.

(4) Measurements of color in reflection and of light transmission (LT) were carried out on each of the laminated glasses I1, I2 and C1 with the aid of a Minolta CM5 colorimeter (illuminant D65, 2° observer, specular reflection included). The measurements of color in reflection, expressed in the CIE L*a*b* system, are performed on the outer surface of the second glass sheet (surface 20b with reference to FIG. 1). The measurements of LT correspond to the light transmission from the outer surface of the second glass sheet to the outer surface of the first glass sheet (from the surface 20b to the surface 10b with reference to FIG. 1). The results are summarized in table 1.

(5) TABLE-US-00001 TABLE 1 L* a* b* LT C1 25.8 3.1 −6.8 11.7 I1 27.5 8.0 −17.6 10.0 I2 14.1 18.4 −33.0 10.4

(6) The laminated glass according I1 to the invention has higher a* and b* coordinates, as absolute values, than the laminated glass C1, which results in a more intense color, while having a substantially equivalent LT. This effect is even more pronounced for the glass I2 according to the invention.

EXAMPLE 2

(7) A laminated glass I3 according to the invention was prepared in an identical manner to the glass I1 except that the PVB used is formed of three zones: a colorless first zone, a yellow (Vanceva® Sahara Sun) second zone and an orange (Vanceva® Tangerine) third zone.

(8) In comparison, a laminated glass C2 was prepared in an identical manner to the laminated glass I3, except that the first glass sheet has no coating.

(9) The measurements of color in reflection, expressed in the CIE L*a*b* system, are carried out with the aid of a Minolta CM5 colorimeter on the outer surface of the second glass sheet (surface 20b with reference to FIG. 1), for each of the colorless, yellow and orange zones of the glasses I3 and C2. The differences in color between the colorless and yellow zones (ΔE*.sub.i/j), colorless and orange zones (ΔE*.sub.i/o), and yellow and orange zones (ΔE*.sub.j/o) were calculated. A high ΔE* denotes a significant difference in tint. The results are summarized in table 1.

(10) TABLE-US-00002 TABLE 2 zone L* a* b* ΔE*.sub.i/j ΔE*.sub.i/o ΔE*.sub.j/o C2 Colorless 33.1 −1 −0.4 7.9 9.3 11.0 Yellow 33.5 −4.5 6.7 Orange 30.9 6.1 5.2 I3 Colorless 52.9 −2.8 −2.9 25.8 32.5 32.5 Yellow 52 −11.8 21.3 Orange 39.5 18 18.2

(11) The ΔE*.sub.i/j, ΔE*.sub.i/o, and ΔE*.sub.j/o values are markedly higher for the laminated glass I3 according to the invention compared to the laminated glass C2. The various colorless, yellow and orange zones consequently appear more contrasted and better defined for the laminated glass according to the invention.