Process and plant for obtaining colored glazing

Abstract

A process for depositing a coating on a glass substrate includes co-sputtered simultaneously by a plasma, in one and the same chamber of the vacuum deposition device, a first constituent made of a material consisting of an oxide, a nitride or an oxynitride of a first element and a second constituent consisting of the metallic form of a second element. The process also includes introducing a hydride, a halide or an organic compound of a third element, different than the first element, into the plasma, to recover the substrate covered with the coating comprising the first, second and third elements at the outlet of the device. The coating consists of metal nanoparticles of the second element dispersed in an inorganic matrix of the first and third elements. The coating displays a plasmon absorption peak in the visible region.

Claims

1. A process for depositing a coating on a glass substrate and controlling the final colorimetry of the coating deposited on the glass substrate, said process comprising the following successive steps: a) passing said glass substrate through a device for vacuum deposition by cathode sputtering, b) introducing a gas into said device for vacuum deposition and generating a plasma from said gas, c) co-sputtering simultaneously, in one and the same chamber of the vacuum deposition device, a first constituent made of a material consisting of an oxide, a nitride or an oxynitride of a first element and a second constituent consisting of the metallic form of a second element, said co-sputtering being obtained by means of said plasma, d) introducing a flow of a hydride, a halide or an organic compound of a third element, which third element is selected from the group consisting of titanium, zirconium, tin, indium, aluminum, silicon, and zinc and is different than the first element, into said plasma, and e) recovering said glass substrate, covered with said coating comprising said first, second and third elements, at an outlet of the device, said coating consisting of metal nanoparticles of the second element dispersed in an inorganic matrix of said first and third elements, said coating displaying a plasmon absorption peak in the visible region, or recovering said substrate covered with said coating comprising said first, second and third elements at an outlet of the device and heating the substrate covered with said coating at a suitable temperature and for a sufficient time to obtain a coating consisting of metal nanoparticles of the second element dispersed in an inorganic matrix of said first and third elements, said coating displaying a plasmon absorption peak in the visible region; wherein the final colorimetry of the coating on the glass substrate is controlled by adjusting the rate of flow of the hydride, halide or organic compound of the third element introduced into said plasma.

2. The process as claimed in claim 1, in which, during step e), the suitable temperature is above 400 and below the softening point of the glass.

3. The process as claimed in claim 1, in which the inorganic matrix is an oxide, a nitride or an oxynitride of said first and third elements.

4. The process as claimed in claim 1, in which the first element is selected from titanium, zirconium, tin, indium, aluminum, silicon, or zinc.

5. The process as claimed in claim 1, in which the third element is selected from the group consisting of titanium, zirconium, tin, indium, aluminum, and zinc.

6. The process as claimed in claim 1, in which the first constituent is an oxide of the first element.

7. The process as claimed in claim 1, in which the second constituent is selected from the group of metals consisting of: Ag, Au, Ni, Cr, Cu, Pt, and Pd.

8. The process as claimed in claim 1, in which the gas introduced into said device for vacuum deposition is a neutral gas selected from argon, krypton or helium.

9. The process as claimed in claim 8, in which a reactive gas comprising oxygen and/or nitrogen, is mixed with the neutral gas and introduced into the device.

10. The process as claimed in claim 1, in which step c) comprises co-sputtering, in said device for vacuum deposition by cathode sputtering, of a target comprising parts consisting of a mixture of an oxide, a nitride or an oxynitride of the first constituent and parts consisting of the metallic form of the second constituent.

11. The process as claimed in claim 1, in which step c) comprises co-sputtering, in said device for vacuum deposition by cathode sputtering, of a first target consisting of an oxide, a nitride or an oxynitride of the first constituent and of a second target consisting of the metallic form of the second constituent.

12. The process as claimed in claim 1, in which the first constituent is a titanium oxide, in which said second constituent is selected from the group consisting of Au, Ni, Cu, and Ag, in which the gas introduced into said device for vacuum deposition is argon mixed with oxygen, in which the third element is silicon, and in which the organic compound of the third element is an organometallic silicon compound.

13. The process as claimed in claim 1, which comprises recovering said substrate covered with said coating comprising said first, second and third elements at an outlet of the device and heating the substrate to a temperature above 400 C. and below the softening point of the glass during step e).

14. The process as claimed in claim 1, in which the second constituent is selected from the group of metals consisting of: Ag, Ni, Cu, and Au.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The FIGURE shows the absorption spectra in the visible range of glazing obtained according to the examples (wavelength in nanometers on the abscissa).

(2) The invention, its various aspects and its advantages will be better understood on reading the nonlimiting examples given hereunder, supplied purely for purposes of illustration.

(3) In these examples, the aim is to deposit, by the process of the invention, a colored layer consisting of a matrix of oxides of the elements Ti and Si, in which metal particles of gold are dispersed.

(4) Deposition of the colored layers according to the invention is carried out in a cathode sputtering housing of the magnetron type delimiting a chamber in which an ultrahigh vacuum can be created. In this housing (constituting the anode), the target (constituting the cathode) is installed in the chamber in such a way that during deposition, an RF or DC supply allows a plasma to be generated from a plasma gas, most often argon, krypton or helium, in front of the target, with the substrate travelling parallel to this target. With this setup, it is possible to select the speed of travel of the substrate and therefore the deposition time and the thickness of the layer.

(5) For the target according to the invention, a commercial titanium oxide target (TiOx) is used initially. Pellets of metallic gold are fixed (for example by gluing with a silver adhesive) and regularly spaced on the titanium oxide target to constitute the two-constituent target according to the invention, in such a way that the plasma sputters the two constituents of said target simultaneously.

(6) The power required for generating a plasma from the gas in the device is applied to the cathode. For jointly depositing the element Si on the glass substrate, an organometallic precursor of silicon, HMDSO (hexamethyldisiloxane), is injected into the plasma that has been generated. Deposition takes place under an atmosphere essentially of argon (neutral plasma gas) and a small proportion of dioxygen in the chamber of the housing. More precisely, for all the examples given below, the flow rate of argon injected into the chamber is 25 sccm (standard cubic centimeters per minute) and the flow rate of oxygen injected into the chamber is 10 sccm. The deposition time is about 6 minutes for all the examples. The thickness of the layers thus obtained varies between 10 and 30 nm.

(7) Several layers are deposited according to the same principles, varying the flow rate of the silicon precursor in order to obtain different dielectric matrixes consisting of a mixed oxide of titanium and silicon, in which the ratio of the two elements Si and Ti is adjusted as shown in Table 1 below. Varying said ratio provides variation of the refractive index of the dielectric matrix as well as of the thickness of the layer deposited. Finally, by measuring the refractive index of the coating obtained, it is possible to estimate the amount of silicon present in the material making up said coating (the deposited layer), with a measured index of 2.4 corresponding to a material whose composition is close to TiO.sub.2, and a measured index of about 1.5 corresponding to a material whose composition is close to SiO.sub.2. Table 1 below presents the main parameters of the step of depositing the coating layer according to the present process.

(8) TABLE-US-00001 TABLE 1 Total Deposition Argon O.sub.2 HMDSO Power pressure time Example (sccm) (sccm) (sccm) (W) (bar) (min) 1 25 10 1 500 3.47 6 2 25 10 6 500 3.6 6 3 25 10 8 500 3.66 6 4 25 10 9 500 3.68 6 5 25 10 10 500 3.7 6 6 25 10 12 500 3.74 6 7 25 10 15 500 3.82 6 8 25 10 20 500 4.10 6

(9) After deposition, the substrates provided with the various coatings are annealed at 650 C. in air at normal pressure.

(10) For each example, the properties of the coatings thus deposited are then measured according to the following protocols:

(11) Optical spectra of the samples were recorded using a Lambda 900 spectrophotometer over the wavelength range from 250 nm to 2500 nm. Measurements were carried out in transmission on the layer side and in reflection on the glass side and the layer side. The absorption spectrum and the possible presence of a plasmon absorption peak are deduced from the measurements using the following relation: A=100TR (layer side).

(12) The colorimetric properties of the layers were also measured using the above device on the glazing obtained (layer side). The values L*, a* and b* (International System), which characterize the color rendering, are measured from the spectrum obtained.

(13) The refractive indices and the thicknesses of the material constituting the coatings deposited in the form of a thin layer were measured by the classical techniques of ellipsometry using a variable angle ellipsometer (VASE).

(14) For each of the examples, the results obtained are presented in Table 2 below.

(15) Moreover, the appended figure shows the absorption spectra in the visible of the glazing obtained according to the preceding examples (wavelength given in nanometers on the abscissa).

(16) TABLE-US-00002 TABLE 2 Position of Refractive HMDSO plasmon Perceived Example index (sccm) Colorimetry peak color 1 2.10 1 L* = 80.3 650 nm Cyan a* = 5.9 b* = 3.9 2 1.80 6 L* = 55.7 580 nm Light blue a* = 5.0 b* = 10 3 1.69 8 L* = 54.8 550 nm Sky-blue a* = 2.2 b* = 12.1 4 1.65 9 L* = 52.4 540 nm Indigo a* = 0.6 b* = 11.9 5 1.63 10 L* = 44.9 525 nm Indigo a* = 1.80 b* = 14.4 6 1.59 12 L* = 37.7 520 nm Midnight a* = 0.4 blue b* = 21.3 7 1.54 15 L* = 41.8 520 nm Violet a* = 8.7 b* = 19.8 8 1.54 20 L* = 53.6 520 nm Magenta a* = 18.3 b* = 10.6

(17) The results presented in Table 2 above show the advantages connected with the present invention. In particular, surprisingly, and not previously described, according to a process according to the invention, simple control of the flow rate of HMDSO (precursor of the element silicon) injected during deposition provides control of the final colorimetry of the glazing.

(18) According to the process according to the invention, it is thus possible to control perfectly, and vary over a wide range, the color of glazing very easily and economically, without loss of production.

(19) In particular, simply by depositing a coating layer, it is possible according to the invention, by simple adjustment of the flow rate of the precursor gas in the device according to the invention, to alter the coloration of the final glazing (substrate covered with the coating) quickly and without any difficulty, with a color varying from cyan to various shades and intensities of blue, as well as violet or magenta hues.

(20) Results of the same kind were observed when pellets of metallic silver were used on the TiOx target instead of gold pellets, and various further colorations were obtained by such replacement.

(21) As an example, we may also mention the following possible combination: a target of silicon oxide comprising a small amount of aluminum (for example between 4 and 12 mol % of aluminum, based on the amount of silicon present) and a titanium precursor such as TiPT (titanium tetraisopropoxide), the second constituent of the target being selected from the group of metals consisting of Ag, Au, Ni, Cr, Cu, preferably being selected from Ag, Au.

(22) Of course, according to the invention, it is possible to deposit other layers or other stacks on top (by reference to the glass substrate), or even underneath, the colored coating according to the invention, to endow the glazing with additional functionality, for example control of sunlight, low-emission, electromagnetic shielding, heating, hydrophilicity, hydrophobicity, photocatalysis, antireflective or mirror, electrochromic glass, electroluminescence, photovoltaic.

(23) According to a preferred embodiment of the invention, a protective layer of dielectric material for increasing the mechanical and/or chemical durability of said coating, for example of silicon nitride or silicon oxide, or else of titanium oxide, is deposited on top of the colored coating according to the invention, or even underneath the colored coating. The thickness of this protective layer may be for example of the order of 1 to 15 nm, or even from 1 to 10 nm, or even from 1 to 5 nm.