EP3419945A1

EP3419945A1 - Method for the selective etching of a layer or a stack of layers on a glass substrate

Info

Publication number: EP3419945A1
Application number: EP17710353.8A
Authority: EP
Inventors: Barbara BRUDIEU; Leila DUMOTIER
Original assignee: Saint Gobain Glass France SAS; Compagnie de Saint Gobain SA
Current assignee: Saint Gobain Glass France SAS; Compagnie de Saint Gobain SA
Priority date: 2016-02-26
Filing date: 2017-02-23
Publication date: 2019-01-02
Also published as: MX2018010200A; WO2017144824A1; FR3048245A1; KR20180101585A; FR3048245B1; CN108698920A

Abstract

The invention relates to a method for depositing one or more decorative mineral layers on a glass substrate, comprising steps consisting in: depositing an organic coating on part, but not all of the surface of the substrate, according to a pattern; depositing one or more decorative mineral layer(s) on the thus coated substrate; subjecting the assembly to a heat treatment for combustion of the organic coating; and subsequently removing said coating and the decorative mineral layer(s) covering same, by wiping with a cloth and/or gas jet and/or washing, such that the remaining decorative mineral layer(s) are arranged in a pattern corresponding to the negative of that made with the organic coating. The invention also relates to an intermediate product of the method, and to the use of the glass obtained as a decorative mirror having transparent zones.

Description

METHOD FOR SELECTIVELY ENGRAVING LAYER OR LAYER STACK ON GLASS SUBSTRATE

The invention relates to a glazing on which has been deposited by a physical vapor deposition (PVD) process, mainly magnetron-assisted cathodic sputtering, plasma-assisted chemical vapor deposition (PECVD). Plasma Enhanced Chemical Vapor Deposition) or evaporation or a method of liquid deposition, of one or more thin layers having spatial structuring at scales ranging from several cm to less than 10 μιτι.

The targeted products are decorative: layers modifying the optical properties, the level of reflection in the visible (mirror or anti-reflection ...), colored or absorbent layers to modify the transmittance in the visible for aesthetic purposes, electrochromic layers, electroluminescent , anti-iridescence.

In particular, the invention aims at the industrial manufacture of transparency zones in these layers, that is to say zones of ablation of these layers in patterns that may require an extremely fine resolution of the order of a few μιτι even a few tens of nm in some cases.

The decorative effect is sought for building glazing applications, interior decoration, street furniture and even transport vehicles (land, air, water).

The targeted products are in particular the stacks deposited by magnetron sputtering. The invention relates in particular to the reflecting layers (mirrors) as described in particular in the document EP 0 962 429 A1.

There are currently several solutions for integrating non-continuous layers in a glazing unit, that is, patterned layers, having ablation zones. According to a first solution, it is known to provide a thermal control function not by a conductive thin layer but not a polyvinyl butyral interlayer (PVB) or other containing nanoparticles of a conductive compound such as indium tin oxide (ITO indium tin oxide) for example. In this case, the thermal control is ensured by absorption and not reflection of the energy portion of the spectrum. This solution is only possible for solar control, and inefficient compared to the solution in reflection and requires a laminated glazing.

The second solution consists in etching the layer with silver after deposition so as to selectively remove the silver on sufficiently fine strips (100 μιτι) to be easily perceived by the eye and separated from each other by a few mm depending on the wavelengths which we wish to promote the transmission. Complex patterns can be used for this application in the face. Representatives of this technique are in particular the documents WO9954961 A1 and WO2014033007 A1. In addition, the heating efficiency of a conductive layer depends on its resistance square R ² , the voltage between the electrodes but also the distance between the electrodes. For building applications, this dependency is a problem because, at the same power source, an electrical resistance of the glazing is required for each heating zone size. One solution may be to burn one more time for example a base layer Ag so as to modulate its resistance by global square to enable it to be compatible with the distance between electrodes and the desired surface heating power. On the other hand, a silver-based glazing can be functionalized in the form of an antenna provided the electromagnetic decoupling of the layer with the frame of the car for example. This operation is also ensured by an engraving. Alternative selective etching methods are mainly from the microelectronics industry. Some use temporary layers, others consist of direct engraving. In the microelectronics industry, photolithography: uses temporary layers to mask selective acid attacks. The photo lithography allows very fine engravings (45-90 nm today industrially) but remains limited to the size of the masks today limited by the size of the optics.

The laser etching of the conductive layer is provided by a point-etch laser which will sublimate the thin-film stack by scanning the beam. This operation has a low productivity on large glazings and requires a significant investment compared to the treated surfaces.

Impact etching of ions or electrons has the same limitations as laser etching in terms of productivity. Other engraving methods come from traditional printing.

To date, inkjet printing techniques are still limited for sizes greater than 10m ² at print times greater than one minute.

Screen printing may be preferred over other techniques when a resolution scale smaller than 50 μιτι is desired: this process provides relatively poor edge qualities at these small scales.

The invention therefore aims to provide decorative glazing as defined above, having ablation zones - transparency in resolution patterns that can be very thin, a few μιτι even a few tens of nm.

To this end, the subject of the invention is a process for depositing on a glass substrate a layer or a stack of layers which are essentially mineral (s) decorative (s), characterized in that it comprises the steps of depositing on the substrate an essentially organic coating on a part but not all of its surface, in accordance with a pattern,

depositing on the substrate thus coated a layer or a stack of essentially mineral (s) decorative layers, to

subjecting the assembly to a heat treatment so as to effect the combustion of the essentially organic coating, then to

- Eliminating it and the layer or stack of essentially mineral (s) decorative layers (s) which covers it by wiping such as cloth and / or gaseous and / or wash, so as to obtain the layer or the stack of essentially mineral layers (s) decorative (s) in a pattern corresponding to the negative of that made with the substantially organic coating.

The product of the combustion of the organic coating is a powder which does not adhere to the substrate, so that it can then be removed with the mineral layer (s) which covers it (s) without exerting a mechanical action of the type brushing, friction or any abrasion likely to deteriorate the substrate and especially the quality of the edges of areas not printed by the organic coating and covered with the mineral layer (s) (sharpness, resolution).

The method makes it possible to produce on an industrial production line, on a large-area substrate, a substantially organic coating pattern with a surface area of dimensions ranging from 1 m to 10 μιτι or less. The reduced cycle time makes it possible to validate the applicable character industrially.

The method of the invention may end with the deposition of a layer of paint above the layer or stack of decorative layer (s) when the one (s) is (are) reflective (s), or above another reflective layer covering this (these) mineral layer (s) decorative (s). This measurement is classic in the making of mirrors.

The method of the invention may also comprise the formation of a metallic discontinuous layer associated with one or more layers dielectric, as described in WO2015177474A1. These layers have the function of modifying the absorption spectrum in the visible of a mirror so as to produce a reflection image whose color is modified.

Preferably, the pattern-based deposition of the essentially organic coating is carried out by a liquid, direct or indirect engraved roll method such as offset, flexography, inkjet printing, masking, lithography or screen printing. . A roll with a width of at least 3210mm (Full Float Width - PLF) can be used, the engraving of which will reproduce the desired pattern. In this case it is a repetitive pattern but it remains compatible for example with the improvement of electromagnetic transmission.

Preferably, the essentially organic coating is chosen from a monomer and / or oligomer acrylate, epoxy acrylate, polyester acrylate, polyurethane acrylate, polyvinylpyrrolidone + EDTA composition, polyamide, polyvinyl butyral, positive photosensitive resin diazonaphthoquinone-novolac, any organic material crosslinked under radiation ultraviolet or infrared, alone or in a mixture of several of them.

Preferably, the substantially organic coating has a thickness of at most 30, and in order of increasing preference, at most equal to 20 and 10 μιτι, and particularly preferably of approximately 5 μιτι. Thicknesses of 1 μιτι or even a few hundred nm are however not excluded from the invention. Apart from the printed areas of this organic coating corresponding to patterns ranging from 1 m to 10 μm or less in surface dimensions, it is necessary to have no temporary organic coating so as not to degrade the decorative mineral stack in these supposed areas. have an intact mineral stack after quenching.

Preferably, prior to the deposition of the essentially mineral layer (s) of layer (s), the development of the essentially organic coating comprises a crosslinking by heat treatment and / or under radiation such as ultraviolet (UV ) and / or drying, then the whole is washed. The essentially organic coating may be advantageously crosslinked under UV to limit the space required for drying. However, it will be ensured that the creep of the essentially organic coating (varnish, resin, etc.) before crosslinking is limited in order to avoid the loss of accuracy of the pattern.

The varnish or resin will be properly dried before going under a conventional washing machine to coater and then the deposition operation of the (mineral) thin layer (s) essentially mineral (s) decorative (s) is performed. One could also consider washing the glass before the partial deposition (printing) of the organic coating, then perform this printing optionally followed by crosslinking, then enter directly into the coater (without prior washing).

Preferably, the layer or stack of essentially mineral (s) decorative layers (s) is formed (e) by a physical vapor deposition (PVD for Physical Vapor Deposition) under vacuum such as cathodic sputtering especially assisted by magnetron, evaporation or plasma enhanced chemical vapor deposition (PECVD for Plasma Enhanced Chemical Vapor Deposition) or liquid.

Preferably, the layer or the stack of layers essentially mineral decorative (s) consists of Ag, Cr, Ti, Al, Nb, Cu, Au, Ga or similar metal metal oxide such as Ti, Si, Sn, Zn or the like, transparent conductive oxide (TCO) such as tin doped indium oxide (ITO), zinc doped indium oxide (IZO), ZnO: Al, stannate cadmium, compound of Si and N such as Si ₃ N ₄ undoped or doped with Al or the like, dielectric stack thereon, alone or in combination of several of them.

The glass can not be cut once soaked, it can be, in some applications, for example building, stored and cut, started etc. before quenching. This glazing can be sold as such, mainly in this case with a layer then removed by quenching at a transformer. Preferably, the heat treatment is part of a thermal tempering of the glass substrate. During quenching, the varnish or the resin disappears by combustion and effectively eliminates the layer or stack of essentially mineral layers (s) decorative (s) at the locations of the grounds, which causes the desired selective etching.

In a particular embodiment, the heat treatment is part of a bending of the glass substrate, in particular a bending by pressing. In this case, a preliminary heat treatment causes the disappearance of the varnish or the resin. If pressing tools are used to bend, it will be ensured that the combustion of the essentially organic coating takes place before this pressing phase.

According to a variant of the process, after the deposition of the layer or the stack of essentially mineral (s) decorative layers (s), is deposited again at least one essentially organic coating sequence - layer or stack of essentially mineral layers (s) decorative (s). This deposition is preferably carried out before the heat treatment for the combustion of the essentially organic coating closest to the substrate, and a subsequent heat treatment will produce the combustion of several superimposed organic overlays as well as the subsequent removal of several layers or layers of layers. essentially mineral decorative covering them. However, the deposition of essentially organic coating sequences - layer or stack of essentially mineral (s) decorative layers (s), from the second sequence, after the combustion heat treatment of the first substantially organic coating and wiping or gaseous blast removal of its organic residues and mineral residues covering them, is also part of the invention. It is thus possible to combine different patterns of areas of transparency of a mirror, or such areas of transparency with differently colored areas.

The glass substrate obtained by the process of the invention is also capable of being integrated in a laminated glazing unit or other laminated composite product, and / or in a multiple glazing unit. Other objects of the invention consist in

a glass substrate coated with at least one sequence consisting of a substantially organic coating that is not easily removable by washing with water (optionally acidified or based on) or organic solvent, on a part but not on its entire surface, in accordance with a pattern, covered with a layer or stack of essentially mineral (s) decorative layers; it is therefore an intermediate product (intended for routine commercialization) of the process of the invention;

the application of a glazing obtained by a method as described previously as a decorative mirror having zones of transparency in accordance with a pattern; it may be a layer glazing modifying the optical properties, the level of reflection in the visible (mirror or anti-reflection ...), colored or absorbent layers to modify the transmittance in the visible for aesthetic purposes, electrochromic, electroluminescent, anti-iridescent layers, for building, interior decoration, street furniture and even transport vehicles (land, air, water).

The invention will be better understood in light of the following examples.

Example 1 Referring to Figure 1, the method of the invention can be represented in four views corresponding to three successive main steps, from left to right in the Figure.

A UV crosslinkable acrylate lacquer having the following formulation is used, in which the proportions are by weight: 57% of aliphatic urethane hexaacrylate oligomer (CN9276 manufactured by Sartomer), 38% of monomers and more exactly 19% of tricyclodecanedimethanol diacrylate (TCDDMDA or SR833S from Sartomer) as well as 19% trimethylolpropane thacrylate (TMPTA or SR351 from Sartomer) and finally 5% of ketone-type photoinitiator is more precisely a mixture of benzophenone and methanone (Speedcure 500 or Irgacure 500 from BASF). This varnish is prepared by mechanically mixing all these compounds (resins and photoinitiator) using a blade. After several hours of agitation, the varnish can be stored for several months if it is protected from light and strong temperature variations.

To make the deposit, a certain amount of this varnish is applied to the clean glass and sharpened by the method of indirect gravure roller as shown in step 1 of Figure 1. After rolling, the substrate + varnish deposited is exposed to UV (mercury type lamp). The thickness of the lacquer pattern coating is 5 μιτι.

A stack of thin layers is deposited in a conformal manner by sputtering in step 2 on the glass + acrylate varnish system. This stack of thin layers has the following constitution (starting from the glass substrate), in which the thicknesses are in nm: SiO 2 20 / Cr 27 / Si 3 N: Al 1 1, 7 / TiO _x 2.3. This stack reflecting the visible light is soakable.

During a quenching step (3 in FIG. 1), generally in a convection oven at 730 ° C. for 35 seconds per mm of glass (140 seconds for a 4 mm thick glass), the organic layer is degraded. which leads to the detachment of the magnetron layers in the areas where it is present. The final system consists of the stack of thin layers described above, structured in a pattern corresponding to the negative of that made with the resin.

Excellent results were also obtained by applying the varnish by screen printing, which made it possible to form a layer 10 m thick.

Example 2 This example differs from the previous one by the essentially organic coating. This is an ink jet deposit of an ink marketed by the Marabu Company in the Ultra-Jet DUV A range, especially in cyan or magenta color. A thickness of a few hundred nm to a few μιτι is obtained. The ink (patterns) is cross-linked under ultraviolet light. The resolution provided by the process of the invention depends solely on the method of printing the organic coating. It is not or little modified during quenching. Printed lines having a fineness of 25 μιτι gave a pattern width in transparency of 25 μιτι (line of ablation of the reflective stack in the visible).

Claims

1. A process for depositing on a glass substrate a layer or a stack of essentially mineral decorative layers, characterized in that it comprises the steps of

depositing on the substrate an essentially organic coating on a part but not all of its surface, in accordance with a pattern, to deposit on the substrate thus coated a layer or a stack of layers essentially mineral (s) decorative (s), to

removing it and the layer or stack of essentially mineral layers (s) decorative covering it by wiping such as cloth and / or gaseous and / or wash, so as to obtain the layer or l stack of essentially mineral (s) decorative layers (s) in a pattern corresponding to the negative of that made with the essentially organic coating.

2. Method according to claim 1, characterized in that the deposition according to a pattern of the essentially organic coating is carried out by a liquid process, direct or indirect engraved roll such as offset, flexography, jet printing. ink, masking, lithography or screen printing.

3. Method according to claim 2, characterized in that the essentially organic coating is selected from a monomer and / or oligomer acrylate, epoxy acrylate, polyester acrylate, polyurethane acrylate, composition polyvinylpyrrolidone + EDTA, polyamide, polyvinyl butyral, positive photosensitive resin type diazonaphthoquinone -novolaque, any organic material crosslinked under ultraviolet or infrared radiation, alone or in a mixture of several of them.

4. Method according to one of the preceding claims, characterized in that the substantially organic coating has a thickness at most equal to 30, and in order of increasing preference, at most equal to 20 and 10 μητι, and particularly preferably of approximately 5 μιτι.

5. Method according to one of the preceding claims, characterized in that prior to the deposition of the layer or the stack of essentially mineral layers (s) decorative (s), the development of substantially organic coating comprises a crosslinking treatment thermal and / or radiation such as ultraviolet and / or drying, then the whole is washed.

6. Method according to one of the preceding claims, characterized in that the layer or the stack of essentially mineral (s) decorative layer (s) is formed (e) by a physical vapor deposition process (PVD for Physical Vacuum Vapor Deposition) such as cathodic assisted sputtering assisted by magnetron, evaporation or plasma enhanced chemical vapor deposition (PECVD for Plasma Enhanced Chemical Vapor Deposition) or liquid.

7. Method according to claim 6, characterized in that the layer or the stack of essentially mineral layers (s) decorative (s) consists of Ag, Cr, Ti, Al, Nb, Cu, Au, Ga or similar metal, metal oxide such as Ti, Si, Sn, Zn or the like, transparent conductive oxide (TCO) such as tin-doped indium oxide (ITO), zinc-doped indium oxide ( IZO), ZnO: Al, cadmium stannate, composed of Si and N such as undoped or doped Al or other doped Si3N, afferent dielectric stack, alone or in combination of several of them.

8. Method according to one of the preceding claims, characterized in that the heat treatment is part of a thermal quenching of the glass substrate.

9. Method according to one of the preceding claims, characterized in that the heat treatment is part of a bending of the glass substrate.

10. The method of claim 9, characterized in that the bending is performed by pressing.

1 1. Method according to one of the preceding claims, characterized in that after the deposition of the layer or the essentially inorganic mineral layer (s), is deposited again at least one essentially organic coating layer - layer or stacking of essentially mineral (s) decorative layers.

12. Glass substrate coated with at least one sequence consisting of an essentially organic coating which is not readily removable by washing with water or an organic solvent, on a part but not on its entire surface, in accordance with a pattern covered with a layer or stack of essentially mineral (s) decorative layers.

13. Application of a glazing obtained by a method according to one of claims 1 to 1 1 as a decorative mirror having areas of transparency in a pattern.