Heat treatable coated article having diamond-like carbon comprising coating

Abstract

A coated article having a coating system comprising a layer of diamond-like carbon (DLC), a metallic, single or multilayer release coating and an oxygen barrier layer. The metallic, single or multilayer release coating comprises one or more layers of silver or silver containing metal alloys, or one or more layers of copper or copper containing metal alloys. The silver or copper comprised in the coating system are advantageous as they do not react with the underlying DLC layer and are sufficient to be provided as thin layers to protect the underlying DLC layer during heat treatment rendering the heat-treated coated article scratch resistant comprising the DLC layer and optionally one or more ion diffusion layers between the glass substrate and the DLC layer. The coating has good mechanical stability and good ageing resistance before heat treatment. The release layer and oxygen barrier layers can easily be removed after heat treatment. Thus, a DLC coating of exceptional quality and high scratch resistance is obtained.

Description

[0001] HEAT TREATABLE COATED ARTICLE HAVING DIAMOND-LIKE CARBON COMPRISING COATING

[0002] Technical Field

[0003] The present disclosure relates, in general to coatings comprising diamond-like carbon (DLC) provided on a substrate. More specifically, the invention relates to an improved multilayer coating system comprising a DLC layer for providing heat treatable DLC layers.

[0004] Background

[0005] For many applications, it is desirable to provide a substrate surface with improved scratch resistance. Soda lime glass does not inherently have a high scratch resistance, but the application of a suitable thin film can markedly improve the scratch resistance of the glass surface.

[0006] A solution to improve the scratch resistance of a glass surface is urgently required, particularly for indoor applications. Diamond-like carbon (DLC) thin films are generally well suited for improving the scratch resistance of a surface, since they have a low coefficient of friction and a sufficiently high hardness. For example, WO 2004 / 071 981 A2 describes an ion beam method for depositing DLC layers. CN 105441871 A relates to the preparation of superhard DLC layers by means of PVD and HI PI MS methods. WO 2016 / 171627 Al relates to the coating of a substrate, the coating comprising a carbon layer such as DLC, which can be applied by means of physical vapor deposition, e.g. by means of high-power pulse magnetron sputtering. Further methods and devices for DLC coating are mentioned, for example, in CN 20383434012 and JP 2011-068940.

[0007] A problem with DLC coatings is their temperature sensitivity. At high temperatures the DLC graphitizes (shift from sp 3 to sp 2 coordination of the carbon atoms) and simply bums to CO2 at temperatures of> 400 ° C. Since glass hardening processes (tempering) require temperatures of up to 700 ° C, pure DLC coatings on glass simply disappear if they are not protected from oxidation. To provide heat treatable or temperable DLC layers, two main methods are known. The first method relies on Si doping of the DLC layers themselves to provide temperature resistance during heat treatment. In the other method, additional protective and removal layers are used to protect the DLC layer from oxygen (oxygen barrier layers) and thus prevent the burning of the DLC layer during the heat treatment. The protective and removal layers can be removed again after the heat treatment. Protective and removal layers for protecting DLC from burning off during tempering is disclosed in WO 2004 / 071981, US 7060322 B2, US 8443627 or US 8580336 B2. In general, the coating concept proposed in the above-referenced prior art have the following layer sequence: substrate (e.g. glass) / base layer / DLC / release layer / anti -oxidation layer.

[0008] A substrate with such a coating can be tempered, the DLC layer being adequately protected. The release and anti -oxidation layers must, however, be quite thick (> 100 nm) to achieve adequate protection of the DLC layer. Removal of the release and protective layers after tempering is also very laborious and usually requires washing in acetic acid solution.

[0009] Different materials are proposed in the art for the release and antioxidation layers. WO 2019 / 020485 Al describes layer systems in which release layers comprising Mg or Sn are used.

[0010] Generally known in the art are release layers based on oxides, suboxides, nitrides and / or subnitrides of boron, titanium boride, magnesium, zinc, tin or aluminum and mixtures thereof. The known systems with barrier layers based on substoichiometric zinc oxides prevent the oxidation of DLC layers on glass. Release layers based on magnesium oxides or magnesium suboxides between the DLC layer and the barrier layer facilitate the removal of the barrier layer post heat treatment.

[0011] However, the oxygen barrier layers must be relatively thick (> 100 nm) to achieve satisfactory protection of the DLC layers. Furthermore, the removal of the barrier layers after the heat treatment is quite tedious and can e.g., require washing with acetic acid solutions. In addition, magnesium suboxide based stripping layers are difficult to handle during the process due to the instability and reactivity of Mg. Furthermore, sputtering of magnesium, raises concerns related to Environmental Protection, Health, and Safety (EHS).

[0012] Hence, the objective of the present invention is to overcome the disadvantages described above in the prior art. In particular, the objective is to provide a protective system for substrates provided with DLC layers, such that heat treatment or annealing does not affect the underlying DLC layer; whereby production, handling, and processing of the coating systems before heat treatment, particularly with respect to EHS, and the removal of the protection system after the heat treatment, are simplified. Furthermore, the protective systems should be stable on storage and the barrier layer for oxygen protection should be as thin as possible.

[0013] The present invention thus relates to a temperable or heat treatable coating system comprising at least one DLC layer on a substrate, in which the DLC layer has no haze and maintains good mechanical properties viz., scratch resistance, especially compared to uncoated tempered glass substrate. The present invention utilizes materials in the release layers that are environmentally safe, easy to handle (during coating) and easy to remove (after tempering). Furthermore, the release layer materials of the present invention are selected such that their deposition at a reduced thickness (much less than 100 nm conventionally taught in the prior art) still provides for the above-mentioned properties and / or advantages.

[0014] It is thus a purpose of this disclosure to help achieve all the said characteristics, detail of which will become apparent to the skilled artisan once given the following disclosure.

[0015] Summary of the Disclosure

[0016] In one aspect of the present disclosure, a coated article comprising a substrate having a coating on one of the two surfaces of the substrate is disclosed. The coating comprising starting from the surface of the substrate and moving away in order: a layer of diamond-like carbon; a metallic, single or multilayer release coating and an oxygen barrier layer. The metallic, single or multilayer release coating comprises one or more layers of silver or silver containing metal alloys, wherein the proportion of silver ranges between 50% to 99.9%, preferably between 75% to 99.9%; and most preferably between 90% to 99.9%; or one or more layers of copper or copper containing metal alloys, wherein the proportion of copper ranges between 50% to 99.9%, preferably between 75% to 99.9%; and most preferably between 90% to 99.9%.

[0017] In another aspect of the present disclosure, a process for making a heat-treated coated article is disclosed. The process comprising the steps of: providing a coating comprising a layer of diamond-like carbon 120, a metallic, single or multilayer release coating and an oxygen barrier layer on one of the two surfaces of the article; heat treating the article provided with the coating at a temperature ranging between 300 to 800 degree Celsius; and removing the oxygen barrier layer and the metallic, single or multilayer release coating from the heat treated coated article by a washing process.

[0018] Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.

[0019] Brief Description of the Drawings

[0020] Embodiments are illustrated by way of example and are not limited to those shown in the accompanying figures.

[0021] FIG. 1 is a schematic representation of a coated article demonstrating a coating system according to one embodiment of the present disclosure;

[0022] FIG. 2 is a schematic representation of a coated article demonstrating a coating system according to another embodiment of the present disclosure;

[0023] FIG. 3 is a schematic representation of a coated article demonstrating a coating system comprising a single metallic release layer of silver, according to one embodiment of the present disclosure;

[0024] FIG. 4 is a schematic representation of a coated article demonstrating a coating system comprising a single metallic release layer of copper, according to one other embodiment of the present disclosure; FIG. 5 is a schematic representation of a coated article demonstrating a coating system deposited over a previously coated article, according to another embodiment of the present disclosure;

[0025] FIG. 6A to 6D are photos of inventive sample 4 and comparative sample post Erichsen Scratch Test (EST);

[0026] FIG. 7A and 7B show microscopic images of sample 1;

[0027] Fig. 7C and 7D show microscopic images of sample 4; and

[0028] Fig. 8A and 8B show microscopic images of clear (comparative example) samples

[0029] Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale.

[0030] Detailed Description

[0031] The invention thus relates to a coated article 100, comprising a substrate 101 provided with a coating 200 comprising starting from the substrate in order: a layer of diamond-like carbon (DLC) 120, a metallic, single or multi-layer release coating 130 and an oxygen barrier layer 150, wherein the metallic, single- or multi-layer release coating 130 is made of silver or silver containing metal alloys or made of copper or copper containing metal alloys. A coated article 100 demonstrating the coating system according to one embodiment of the present disclosure is illustrated in Fig. 1. In this preferred embodiment of the method according to the invention, after the deposition DLC layer, a release layer and oxygen barrier layer are applied as additional layers. These additional layers make the heat treatment of the substrate with DLC layer possible. If no heat treatment is desired, the release layer and the oxygen barrier layer can be dispensed with. The following information relates to the coated article before a heat treatment, unless expressly stated otherwise.

[0032] It has been found that the DLC coating 120 of excellent quality with high scratch resistance after heat treatment was obtained by using a thin overlying metallic layer(s) comprising silver or copper. Because of the reduced thickness of the overlying layer(s) used in the present invention, the operational requirements for providing a thick overlayer is substantially reduced and the issue of haze associated with washing of such thick overlying layer(s) in a coated heat-treated articles is eliminated.

[0033] In addition, the coatings showed a good mechanical stability and good aging stability before heat treatment. The EHS situation is significantly improved, especially when compared to magnesium, particularly because silver and copper are safer to use in the sputtering process than magnesium. The coated article according to the invention thus shows improved stability with respect to handling and storage life before heat treatment compared with coated substrates according to the prior art and exceptional protection of DLC layer during heat treatment. The problems with EHS in the manufacture, storage, handling, and removal of the layer(s) overlying the DLC layer are minimized. Even relatively thin barrier layers provide good protection. Furthermore, the detachment of the oxygen barrier layer from the metallic layer is quick and easy.

[0034] The substrate of the coated article 100 of the present invention may be any substrate. The substrate is preferably made of ceramic, glass or glass ceramic, wherein the substrate is preferably a glass substrate. Preferred examples of glass are soda lime glass, borosilicate glass or aluminosilicate glass. The soda lime glass can be clear or tinted. In a preferred embodiment, the substrate is a glass sheet. The thickness of the substrates, in particular of the glass substrates, can vary within wide ranges, wherein the thickness may be in the range of 0. 1 mm to 20 mm.

[0035] The coating 200 of the coated article 100 according to the invention comprises, starting from the substrate, in this order: a) a layer diamond-like carbon (DLC) 120, b) a metallic, single or multilayered release coating 130 and c) an oxygen barrier layer 150. Of the three layers, the layer of diamond-like carbon 120 is closest to the substrate. The metallic, single or multi-layer release coating 130 is over the layer diamond-like carbon arranged and the oxygen barrier layer 150 is disposed over the metallic, single or multilayered release coating 130. It should be generally understood that the following information on the coated article refers to the substrate prior to heat treatment, unless expressly stated otherwise. A heat treatment can lead to changes, in particular with regard to the metallic layer and the oxygen barrier layer.

[0036] Layers of diamond-like carbon are well known. Diamond-like carbon is usually abbreviated to DLC (for "diamond-like carbon"). In DLC layers, hydrogen-free or hydrogen-containing amorphous carbon is the predominant constituent, wherein the carbon may consist of a mixture of sp 3 and sp 2 - hybridized carbon, optionally sp 3 hybridized carbon or sp 2 -hybridized carbon may be predominate. Examples of DLC are those with the designation ta-C and a C-H. A DLC layer may also contain foreign atoms, such as silicon, metals, oxygen, nitrogen or fluorine, as dopant. The DLC layer used according to the present invention can be doped or undoped.

[0037] The person skilled in the art knows various methods for producing DLC layers. DLC layers are typically applied to the substrate by a vapor deposition process, e.g., by physical vapor deposition (PVD), by evaporation or sputtering, or by chemical vapor deposition (CVD). Preferably used deposition methods are plasma enhanced CVD (PECVD) and ion beam deposition. As precursors hydrocarbons, in particular alkanes and alkynes, such as C2H2 or CH4, are used.

[0038] In a particularly preferred embodiment of the invention, the DLC layer is formed by means of the so-called magnetron supported PECVD method, in which magnetron PECVD is a PECVD process in which the plasma is generated by a magnetron or a magnetron target.

[0039] In the vacuum, at a pressure of 0.1 pbar to 10 pbar, at least one reactant gas is introduced into the plasma generated by the magnetron target, whereby fragments of the reactant gas are formed, which are deposited on the substrate to form the DLC layer. The reactant gas is hydrocarbons, especially alkanes and alkynes, such as C2H2 or CH4, or organosilicon compounds, example Tetramethylsilane. Optionally, additional inert gases, such as argon, are introduced into the vacuum chamber for supporting plasma. The magnetron target can be silicon, which optionally with one or more elements, such as aluminum and / or boron or titanium are added as dopant. In a particularly preferred embodiment, the magnetron PECVD method is operated so that the magnetron target is in the poisoned mode during DLC deposition.

[0040] The production of the DLC layer by means of the magnetron PECVD method is advantageous since it allows substrates to be coated over a large area and with good process stability with DLC, without the need for intensive heating of the substrate. The layers thus produced have excellent scratch resistance and good optical properties.

[0041] In a preferred embodiment, the DLC layer 120 has a layer thickness of 2 nm to 10 nm, preferably from 3 nm to 8 nm. These layer thicknesses are advantageous because it ensures high transparency of the layers.

[0042] The metallic, single or multilayer release coating 130 comprises silver or silver containing metal alloys or comprises copper or copper containing metal alloys. The alloying elements for silver and copper are usually metals and / or semimetals. According to certain embodiments of the present invention, the coated article 100 comprises a metallic layer based on silver is shown in Fig. 3. According to certain other embodiments of the present invention, the coated article 100 comprises a metallic layer based on copper is shown in Fig. 4.

[0043] The metallic, single-layer or multi-layer release coating 130 used according to the invention has the advantage that it is more stable than conventional layers. The problems with EHS are reduced. In addition, this layer is easier and faster to remove than conventional layers.

[0044] In a particularly preferred embodiment, the metallic layer comprises one or more layers of silver. In this embodiment, the metallic layer is usually single layered. Suitable alloying elements for silver are all customary alloying metals known to the person skilled in the art. For example, the at least one alloy element for silver can be selected from the group consisting of copper, antimony, lead, Indium, gallium, germanium, aluminum, gold, tin, zinc, cadmium or a combination thereof. In still other embodiments of the present invention, the metallic release layer 130 may optionally additionally comprise at least one other alloying element apart from the non-preferred examples. In a particularly preferred embodiment, the metallic layer comprises one or more layers of copper. In this embodiment, the metallic layer is usually single layered. Suitable alloying elements for copper are all customary alloying metals known to the person skilled in the art. For example, the at least one alloy element for copper can be selected from the group consisting of silver, tin, zirconium, chromium, zinc, aluminium, silicon, nickle or a combination thereof. In still other embodiments of the present invention, the metallic release layer 130 may optionally additionally comprise at least one other alloying element apart from the aforementioned non-preferred examples

[0045] In another embodiment, the metallic release layer is formed from two, three or more layers, wherein one or more layers containing or consisting of silver or copper and one or more layers containing or consisting of at least one alloying element for silver or copper, preferably selected from copper, antimony, lead, Indium, gallium, germanium, aluminum, gold, silver, tin, zirconium and / or chromium are arranged alternately.

[0046] An alternating arrangement is understood to mean that one or more layers containing copper or alternatively silver (layer a) and one or more layers containing at least one alloying element for copper or silver (layer b) are arranged alternately, it being immaterial is which layer is applied first, the order of the position is therefore eg: a / b; b / a; a / b / a; b / a / b; a / b / a / b; b / a / b / a / b etc. The layers containing at least one alloying element for copper or silver (layer b) may each contain the same alloying element (s), but different alloying elements may also be present in these layers. If it contains two or more alloying elements, the alloying elements may also be included as an alloy.

[0047] The thickness of the individual layers may be the same or different. The thickness of a single layer in a multilayer metallic release layer may, in the range of 2 nm to 20 nm, preferably 4 nm to 15 nm. In a preferred embodiment, the metallic, single-layer or multi-layer release coating as a whole has a layer thickness of 2 nm to 20 nm, preferably 4 nm to 15 nm.

[0048] The metallic, single or multi-layer release coating 130 is deposited on the substrate provided with the DLC layer or on a coated substrate provided with the DLC layer by means of well-known methods to vapor deposition methods, preferably by sputtering, co-sputtering or ion beam evaporation. Even alloys can be sputtered with a target of the corresponding alloy easily.

[0049] The advantages of the metallic release coating 130 of the present invention being made of silver or silver containing alloys or Copper or copper containing alloys are: firstly, the coating 130 do not react with the underlying DLC layer 120 to form carbides; and secondly, the coating 130 exhibit reduced adhesion with the underlying DLC layer 120 that aids in easy removal of the coating 130 post heat treatment in a washing step.

[0050] In all embodiments of the present invention, the release coating 130 made of silver or silver containing metal alloy has a proportion of silver ranging between 50% to 99%. Likewise, in all embodiments of the present invention, the release coating 130 made of copper or copper containing metal alloy has a proportion of copper ranging between 50% to 99%.

[0051] The metallic, single or multi-layer release coating 130 serves as a release layer as it passes through the heat treatment or an annealing process. In alternative embodiments the release coating 130 together with the oxygen barrier layer 150 can be removed with a simple washing step.

[0052] In embodiments relating to coated articles that comprise of a silver or silver alloy based metallic release layer, the silver release layer is protected with an overlying protective layer 140, as illustrated in Fig. 2 and Fig. 3. The protective layer 140 is provided for protecting the underlying metallic release layer comprised of silver and is usually sandwiched by the underlying silver layer and an overlying oxygen barrier layer 150. The protective layer 140 according to most embodiments of the present invention comprises an alloy of Ni and Cr and is deposited at a thickness ranging between 0.1 nm and 5 nm.

[0053] The protective layer 140 protects the underlying silver-based release coating 130 from oxidation. The protective layer 140 can be easily washed away and after heat treatment and removal of the release coating 130 and the oxygen barrier layer 150, the best optical properties without any blister-related haze was observed on the substrate coated with DLC. The protective layer 140 further improves adhesion of the substrate coated with DLC to the deposition of the oxygen barrier layer 150 thereon.

[0054] The coating 200 of the coated substrate 100 of the present invention further comprises an oxygen barrier layer 150. The oxygen barrier layer 150 protects the DLC layer, especially from the ambient oxygen. The oxygen barrier layer 150 makes it possible to subject the coated substrate 100 with the DLC layer thereon to a heat treatment or annealing, without resulting in a partial or complete degradation of the DLC layer. Such oxygen barrier layer(s) and their formation are well known in the art. The oxygen barrier layer 150 of the present invention comprises silicon nitride, silicon oxynitride, doped silicon nitride or doped silicon oxynitride, with Al, Zr, Ti, Hf and / or B doped silicon nitride. In a preferred embodiment, the oxygen barrier layer 150 is made of silicon nitride or silicon nitride doped with Al or Zr or B. The proportion of doping elements can be, for example, in the range from 0.1 to 100 ppm.

[0055] In all embodiments of the present invention, the oxygen barrier layer 150 has a thickness ranging between 5 nm and 25 nm, preferably between 10 nm and 20 nm.

[0056] For the application of the oxygen barrier layer, the usual methods or vapor deposition methods can be used, for. B. PVD, in particular sputtering, preferably magnetron sputtering, CVD and atomic layer deposition (ALD, atomic layer deposition).

[0057] The combination of the above-explained metallic release coating 130 with a silicon nitride-containing oxygen barrier layer 150 enables a particularly good protection of the DLC layer 120, particularly when Si3N4 doped with Zr or B is used as the oxygen barrier layer. This is advantageous since in this way already a relatively thin oxygen barrier layer with a thickness of not more than 100 nm or even significantly lower such as a thickness taught by the present invention viz., 10 nm and 20 nm provide for adequate protection of the underlying DLC layer. This reduces the manufacturing costs and is also advantageous in terms of a simplified detachment of the layers after the heat treatment.

[0058] The coating system 200 optionally comprises one or more ion diffusion barrier layers 110 precoated on the substrate. Fig. 2 and Fig. 3 illustrate the coating system according to another embodiment of the present invention, wherein an ion diffusion barrier layer 110 is provided between the substrate 101 and the DLC layer 120. The ion diffusion barrier layer 110 prevents unwanted diffusion of ions, such as sodium ions, from the substrate into the coating, especially during the heat treatment. Such ion diffusion barrier layers and their formation are well known in the art. Known common materials can be used for providing the ion diffusion barrier layer. For the application of ion diffusion barrier layers, the usual methods or vapor deposition methods can be used. Sputtering, preferably magnetron sputtering is used.

[0059] In a preferred embodiment, the ion diffusion barrier layer 110 comprises a material selected from silicon nitride, silicon oxynitride, doped silicon nitride or doped silicon oxynitride, with Al, Zr, Ti, Hf and / or B doped silicon nitride. The ion diffusion barrier layer 110 have a thickness ranging between 5 nm and 25 nm, preferably between 10 nm to 20 nm.

[0060] Fig- 4 illustrates a coated article comprising copper based metallic release layer 130. In embodiments comprising copper based metallic release layers, the coating 200 no longer comprises the optional protective layer 140.

[0061] Fig. 3 and Fig. 4 illustrate the coated article 100 according to preferred embodiments of the present invention. The preferred embodiment according to the present invention in which the coated article, particularly glass substrate comprises the coating 200 comprising away from the glass substrate in the below mentioned order: an ion diffusion barrier layer made of aluminum doped silicon nitride; a DLC layer; a metallic release layer made of silver (Fig. 3) or a metallic release layer made of copper (Fig. 4); a protective layer made of nickel chromium overlying the layer of silver based metallic release layer; and an oxygen barrier layer made of aluminum doped silicon nitride.

[0062] In a further advantageous embodiment, the substrate and in particular the glass substrate, together with the layer of diamond-like carbon and one or more optional ion diffusion barrier layers, are transparent. The visible light transmission is more than 50%, preferably more than 70%, and more preferably more than 80%. In alternate embodiment, the substrate can be selected from ceramic or ceramic glass. In yet another alternate embodiment, the substrate is a clear glass substrate or tinted glass substrate, or a coated glass substrate provided with a thin film multilayer coating (300) acting on solar and / or infrared radiation, as referenced in Fig. 5.

[0063] Fig- 5 shows a coated article that uses a coated substrate 101’ provided with a thin film multilayer coating (300) acting on solar and / or infrared radiation. The thin film multilayer coating (300) acting on solar and / or infrared radiation comprises at least one IR reflective layer comprised of a material selected from silver, niobium, niobium nitride, nickel chromium, nickel chromium nitride, titanium or titanium nitride. The multilayer coating (300), in an example embodiment shown in Fig- 5 comprises IR reflective layer of niobium nitride sandwiched by two dielectric layers. The coating system 200 taught by the present invention is deposited over the multilayer coating (300).

[0064] Glass substrates comprising such multilayer coating having niobium nitride are known to be prone to scratches owing to the reduced resistance of the coating itself to scratches and further owing to the use of such substrates as monolithic or single glazing. When these glass substrates comprising such multilayer coating are desired in annealed form, then conventionally a DLC layer is applied over the multilayer coating to provide a scratch resistant product. However, when the glass substrate comprising such multilayer coating are desired in tempered (heat treated) form, then the coating system 200 of the present invention offers the best solution to obtain a tempered solar control glass article that additionally has improved scratch resistance, thanks to the release layer 130 and the oxygen barrier layer 130 overlying the DLC coating 120 that protect the underlying DLC coating 120 during heat treatment. Post heat treatment a tempered scratch resistant solar control glass article is obtained comprising the multilayer coating 300 and the overlying DLC layer 120.

[0065] Thus the present invention provides the solution for making such multilayer coated glass substrates resistance to scratch. This invention is especially beneficial for customers desiring a temperable version of the coated substrate

[0066] The invention further relates to a method for producing a heat- treated coated article having a coating comprising a layer of diamond-like carbon, metallic release layer, oxygen barrier layer and optionally one or more layers of ion diffusion barrier layers, the process comprising the steps of: a. Providing a coating 200 as taught by any one or more embodiments of the present invention to obtain a coated article; b. Heat treatment of a coated article according to the invention as described below; and c. Removing the oxygen barrier layer and the metallic, single or multilayered release coating off the coated article by a washing step.

[0067] The heat treatment may be annealing or tempering. The heat treatment or annealing or tempering, e.g., for a glass substrate, involves a temperature of 300 ° C to 800 ° C, preferably 500 ° C to 700 ° C, more preferably 600 ° C to 700 ° C. The duration of the heat treatment varies depending on the system being treated and the temperature used, but may be e.g., between 1 min to 10 min.

[0068] For the washing step, as washing medium, e.g., Water, acids, alkalis and organic solvents are used, with water being preferred. The washing process can be performed by rinsing with the washing medium, by washing under the action of brushes or preferably by immersion in the washing medium. The washing process can be carried out at ambient temperature (e.g., in the range of 15 ° C to 30 ° C).

[0069] The Oxygen barrier layer and the metallic release layer can be easily removed by simply immersing in a water bath shing medium can optionally also be heated. Due to the relatively non-reactive metallic release layer, the health risk to the product, plant and workers is reduced. Furthermore, the metallic layer and the oxygen barrier layer can be peeled off quickly and easily.

[0070] The coating system 200 can be heat treated or tempered even at high temperatures without affecting the quality of the underlying DLC layer. After the heat treatment, the no longer needed oxygen barrier layer and the metallic release layer are removed in a simple manner by immersion in a water bath.

[0071] The invention also relates to the coated substrate which can be obtained by the method according to the invention. This can be the coated substrate, which comprises the following layers in this order on the substrate: the DLC layer, the release layer, the oxygen barrier layer and optionally the one or more ion diffusion barrier layers applied between the substrate and the DLC layer. The coated substrate can also be the coated substrate, comprising the DLC layer and optionally the one or more ion diffusion barrier layers applied between the substrate and the DLC layer. This is obtained after heat treatment of the substrate with the coating, comprising the DLC layer, the release layer, the oxygen barrier layer and optionally the one or more ion diffusion barrier layers applied between the substrate and the DLC layer, and after subsequent removal of the oxygen barrier layer and the release layer from the heat-treated, coated substrate by the washing process.

[0072] In the following, the invention is explained in greater detail on the basis of non-limiting exemplary embodiments with reference to the accompanying drawings.

[0073] Examples:

[0074] Four coated substrates were prepared on a laboratory scale. Layer structure of sample 1 is shown in Fig. 3. Layer structure of sample 2 is shown in Fig. 4. In al examples, the DLC layer was applied by a PECVD method (e.g., C2H2 precursor for DLC). The other layers were applied to the substrate by a PVD (magnetron sputtering) process.

[0075] Table 1 : Examples of coated article - Inventive Samples

[0076] Alternatively, it would be conceivable to form a metallic release layer of Ag and Cu. For this purpose, e.g. an alternating layer sequence Ag / Cu / Ag / Cu / Ag / Cu, etc. can be selected. In another variant, Ag and Cu could be taken in their alloy form. For example, the following layer sequence would result: Ag alloy / Cu alloy / Ag / Cu etc.

[0077] Testing of Samples:

[0078] All samples showed good temperability and an exceptionally good scratch resistance after heat treatment and removal of the metallic layer and the oxygen barrier layer. The DLC layer could therefore be protected against degradation and oxidation by the oxygen barrier layer of Si3N4:B in all examples. In particular, oxygen barrier layers of Si3N4 doped with B showed excellent protection for the DLC layer during annealing. After the heat treatment, the layers above the DLC layer were advantageously removed with one only one washing treatment with water.

[0079] Furthermore, the metallic layers of sample 1-4 exhibited good mechanical stability prior to annealing, which facilitates processing and storage of the glass which has not yet been heat treated.

[0080] Sample Testing: EST

[0081] The DLC-coated substrates obtained from Samples 1 to 4 were tested using the Erichsen scratch test (EST). The Erichsen scratch test is a device with a turntable on which the sample is fixed and a variable load is applied via a metal tip. By turning the plate, an annular scratch is created. For this purpose, aa tungsten carbide van Laar tip with a diameter of 500 micron with increasing force (increase in force from 0.1 N to 10 N) was placed on the coated substrates and for comparison placed on uncoated soda-lime glass.

[0082] The mechanical scratch resistance of the coated articles was obtained according to above said example and according to the invention after heat treatment at 650°C (both annealed and tempered) and subsequent separation of the release layer and oxygen barrier layer.

[0083] In the Erichsen scratch test, traces (0.1-10 N) are shown in Fig. 6A, which is a photo of the DLC coated sample 4 as prepared. For comparison Fig. 6B shows the photo of an annealed sample having a multilayer coating 300 acting on solar radiation but not the DLC coating taught in the present invention that was tested using the Erichsen scratch test. Likewise, Fig. 6C shows a photo of the DLC coated sample 4 after the sample was tempered and Fig. 6D shows the photo of a tempered sample having the multilayer coating 300 acting on solar radiation but not the DLC coating.

[0084] It is evident from Fig. 6A and 6C that scratches start to appear from 3 N on the inventive samples of the present invention whereas in the comparative samples shown in Fig. 6B and 6D scratches start to appear from 0.1 N onwards. Thus the inventive samples of the present invention are resistant to scratch up to 3N.

[0085] Similar results were obtained when samples 1 - 3 were tested using the Erichsen scratch test (EST).

[0086] Sample Testing: EST + Ceria Polishing

[0087] In this test, samples 1 - 4 were subjected to ceria polishing before performing the Erichsen scratch test (EST) at the maximum force of 10 N. The sample were then viewed in an optical microscope to determine the width of the scratch that resulted from the applied force of 10N. Fig. 7A and Fig. 7B show the microscopic image of sample 1 as prepared and post treatment, respectively. From the images the thickness of the scratch ranges between 55 pm to 85 pm. Likewise, Fig. 7C and 7D show the microscopic image of sample 4 as prepared and post treatment, respectively. From the images the thickness of the scratch ranges between 73 pm to 81 pm.

[0088] Comparatively, Fig. 8A and 8B show the microscopic image of the clear samples (having no DLC coating) in annealed form and tempered form, respectively. In both these images the width of the scratch can be seen to be ranging between 91 pm to 146 pm.

[0089] Thus, the present invention has evidently reduced the impact of scratch and improved the resistance of scratch.

[0090] Industrial Applicability

[0091] The coated article described in the present disclosure finds application in exterior and interior glass applications such as but not limiting to furniture glass, display case glass, picture frame glass, or the like. Following heat treatment of the coated article, the heat-treated coated article includes a glass substrate supporting at least a DLC layer and optionally one or more underlying ion diffusion layer(s) and exhibit excelled scratch resistance. Thus, the invention provides coated article heat treated or not which may be used in window applications, glass shower doors, glass tabletops or the like. It has been found that the deposition of Ag and / or Cu layers overlying the DLC layer remarkably improves the scratch resistance of the DLC layer and such improved scratch resistance also improves corrosion resistance / chemical stability.

[0092] Note that not all of the activities described above in the general description, or the examples are required, that a portion of a specific activity may not be required, and that one or more further activities may be performed in addition to those described. Still further, the order in which activities are listed is not necessarily the order in which they are performed.

[0093] Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims. The specification and illustrations of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The specification and illustrations are not intended to serve as an exhaustive and comprehensive description of all of the elements and features of apparatus and systems that use the structures or methods described herein. Certain features, that are for clarity, described herein in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in a sub combination. Further, reference to values stated in ranges includes each and every value within that range. Many other embodiments may be apparent to skilled artisans only after reading this specification. Other embodiments may be used and derived from the disclosure, such that a structural substitution, logical substitution, or another change may be made without departing from the scope of the disclosure. Accordingly, the disclosure is to be regarded as illustrative rather than restrictive.

[0094] The description in combination with the figures is provided to assist in understanding the teachings disclosed herein, is provided to assist in describing the teachings, and should not be interpreted as a limitation on the scope or applicability of the teachings. However, other teachings can certainly be used in this application.

[0095] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having" or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but may include other features not expressly listed or inherent to such method, article, or apparatus. Further, unless expressly stated to the contrary, "or" refers to an inclusive-or and not to an exclusive-or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present). Also, the use of "a" or "an" is employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural, or vice versa, unless it is clear that it is meant otherwise. For example, when a single item is described herein, more than one item may be used in place of a single item. Similarly, where more than one item is described herein, a single item may be substituted for that more than one item.

[0096] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples are illustrative only and not intended to be limiting. To the extent that certain details regarding specific materials and processing acts are not described, such details may include conventional approaches, which may be found in reference books and other sources within the manufacturing arts.

[0097] While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.

[0098] List of Elements

[0099] TITLE: HEAT TREATABLE COATED ARTICLE HAVING DIAMOND-LIKE

[0100] CARBON COMPRISING COATING

[0101] 100 Coated Article lor Coated Substrate having a Multilayer Coating

[0102] 101 Glass Substrate no Ion Diffusion Barrier Layers

[0103] 120 Diamond-Like Carbon (DLC) Layer

[0104] 130 Metallic Release Layer

[0105] 140 Protective Layer

[0106] 150 Oxygen Barrier Layer

[0107] 200 Coating

[0108] 300 Multilayer Coating Acting on Solar Radiation

Claims

AMENDED CLAIMS received by the International Bureau on 26 Feb 2025(26.02.2025)Claims1) A coated glass article 100 comprising a substrate 101 having a coating 200 on one of the two surfaces of the substrate 101, the coating 200 comprising starting from the surface of the substrate and moving away in order: a layer of diamond-like carbon 120; a metallic, single or multilayer release coating 130; and an oxygen barrier layer 150, wherein the metallic, single or multilayer release coating 130 comprises one or more layers of silver or silver containing metal alloys, or one or more layers of copper or copper containing metal alloys.2) The coated glass article 100 as claimed in claim 1, wherein the coating 200 further comprises a protective layer 140 overlying the metallic single or multilayer release coating 130 comprising silver or silver containing metal alloys or copper or copper containing metal alloys, comprising an alloy of Ni and Cr.3) The coated glass article 100 as claimed in claim 2, wherein the protective layer 140 comprising an alloy of Ni and Cr has a thickness ranging between 0.1 nm and 5 nm.4) The coated glass article 100 as claimed in claim 1, wherein the coating 200 further optionally comprises at least one ion diffusion barrier layer 110 provided between the substrate 101 and the layer of diamond-like carbon 120.5) The coated glass article 100 as claimed in claim 1 or claim 4, wherein the at least one ion diffusion barrier layer 110 and the oxygen barrier layer 150 comprises silicon nitride, silicon oxynitride, doped silicon nitride or doped silicon oxynitride, with Al, Zr, Ti, Hf and / or B doped silicon nitride.6) The coated glass article 100 as claimed in claim 5, wherein the ion diffusion barrier layer 110 and the oxygen barrier layer 150 comprises silicon nitride or silicon nitride doped with aluminum nitride or aluminum or zirconium.7) The coated glass article 100 as claimed in claim 6, wherein the ion diffusion barrier layer 110 and the oxygen barrier layer 150 each have a thickness ranging between 5 nm and 25 nm.8) The coated glass article 100 as claimed in claim 1, wherein the release coating 130 has a thickness ranging between 2 nm to 20 nm.9) The coated glass article 100 as claimed in claim 1, wherein the layer of diamond-like carbon 120 is doped or undoped.10) The coated glass article 100 as claimed in claim 1, wherein the layer of diamond-like carbon 120 has a thickness ranging between 2 nm and 10 nm.11) The coated glass article 100 as claimed in claim 1, wherein the substrate 101 is a glass or ceramic or ceramic glass.12) The coated glass article 100 as claimed in claim 1, wherein the glass substrate 101 is a clear glass substrate or tinted glass substrate or a coated glass substrate provided with a thin film multilayer coating acting on solar and / or infrared radiation.13) The coated glass article 100 as claimed in claim 12, wherein the thin film multilayer coating acting on solar and / or infrared radiation comprises at least one IR reflective layer comprised of a material selected from silver, niobium, niobium nitride, nickel chromium, nickel chromium nitride, titanium or titanium nitride.14) The coated glass article 100 as claimed in claim 1 is heat treated or annealed or tempered involving temperatures ranging between 300 to 800 °C.15) The coated glass article 100 as claimed in claim 14 comprising a layer of diamond-like carbon 120 and optionally one or more layers of ion diffusion barrier layer 110 underlying the layer of diamond-like carbon 120.16) A process of making a heat-treated coated article 100, the process comprises the steps of: providing a coating 200 as claimed in claim 1 comprising a layer of diamond-like carbon 120 on one surface of the article; heat treating the article provided with the coating 200 at a temperature ranging between 300 to 800 °C; and removing the oxygen barrier layer 150 and the metallic, single or multilayer release coating 130 from the heat-treated coated article by a washing process.

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