Exterior components for watches or jewelry having a saturated color coating, and a method for manufacturing the exterior components.

Abstract

To provide: an external part with a bright and saturated color, for example red, obtained by one or more thin layers to preserve the structure of the substrate, the appearance of which does not vary with a user's viewing angle, and which is adapted to be subjected to mechanical stress without degrading; and a method for manufacturing said external part.SOLUTION: A watch or jewelry external part (10), in which the external part (10) includes a substrate (11) on a surface of which extends a coating (12) including a tantalum (Ta)-based nitride or oxynitride having a thickness ranging from 300 nm to 10 μm and an intrinsic and saturated color.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to the field of watchmaking or jewelry, and more particularly to an exterior part of a watch or jewelry essentially provided with a colored coating, and a method for manufacturing the exterior part.

[0002] In the present specification, the term "exterior part" refers to any ornament in the field of watchmaking or jewelry, for example, consisting of a case, a dial, a dial applique, hands, a bezel, a crown, a bracelet link, etc. intended to be visible to the user.

[0003] Preferably, the present invention relates to an exterior part of a watch or jewelry provided with a coating whose solid color is a shade of red.

Background Art

[0004] In the field of watchmaking or jewelry, and more generally in the field of ornaments, deposition methods by painting, varnishing or enameling are not always appropriate.

[0005] In fact, on the one hand, the layer of material applied to the surface of the ornamented article is too thick to show a surface structure, for example, a brushed surface, a sunray-brushed surface, a sandblasted surface or a laser-structured surface, etc., and on the other hand, the lifespan of this layer and its resulting color are not always satisfactory.

[0006] Therefore, thin-film vacuum deposition techniques such as physical vapor deposition (PVD), chemical vapor deposition (CVD) and atomic layer deposition (ALD) are preferred. In fact, these thin-film vacuum deposition techniques enable the deposition of thin and resistant layers, which are generally suitable for coating small and friction-prone parts, for example, provided with a fine surface structure.

[0007] However, despite the fact that these deposition techniques can yield coatings of numerous intrinsic colors, the implementation of these methods does not allow for the acquisition of specific intrinsic colors, such as shades of red, particularly bright and vivid reds, on an industrial scale.

[0008] Furthermore, it is known that stacks of thin layers are deposited to form an interference optical system for generating a predetermined color. However, color perception is likely to be dependent on the viewing angle. Moreover, stacking thin layers presents significant manufacturing constraints, given that the generated color largely depends on the thickness of the thin layer. [Overview of the project] [Problems that the invention aims to solve]

[0009] Therefore, it is necessary to obtain an exterior component having a bright saturated color, such as red, which is obtained by one or more thin layers to maintain the structure of the substrate, and whose appearance does not change depending on the user's viewing angle and is adapted to withstand mechanical stress without deterioration. [Means for solving the problem]

[0010] For this purpose, the present invention relates to an exterior component for a watch or jewelry, comprising a substrate, wherein a coating comprising a tantalum Ta-based metal nitride or oxynitride having a thickness of 300 nm to 10 μm and having a predetermined color is spread on the surface of the substrate.

[0011] In certain embodiments, the present invention may further include, either individually or in any technically possible combination, one or more of the following features:

[0012] In certain embodiments, the coating has a thickness of 1 μm to 3 μm, preferably 2 μm.

[0013] In certain embodiments, the red coating is made of tantalum nitride (Ta) with a stoichiometric composition substantially close to or equal to Ta3N5, so as to have a bright red color.

[0014] In certain embodiments, the coating is produced by adding oxygen in the range of 0 to 5 atomic percent.

[0015] In certain embodiments, the coating has a red color characterized by coordinates a* and b* greater than 20, preferably coordinates a* and b* greater than 50, in the CieLAB color space in the transmission mode of a standard light source D65, at an observer and measurement geometry d:0° of 10°, more preferably coordinates L*=[30;50], a*=[50;70] and b*=[60;80], particularly L*=42, a*=58 and b*=72.

[0016] In certain embodiments, the coating forms an AB(O,N) type composition in which B is tantalum Ta and A is a metallic element.

[0017] In certain embodiments, the metal element A is preferably selected from Ba, Ca, Nd, La, Sr, Eu, and Yb. The coating comprises a composition that is substantially similar to or equal to BaTaO2N, CaTaO2N, NdTaO2N, LaTaO2N, SrTaO2N, EuTaO2N, or Yb2Ta2O5N2, respectively.

[0018] For another purpose, the present invention relates to a method for manufacturing exterior components of a watch or jewelry, as described above, The steps include: depositing a thin layer of tantalum Ta-based metal oxide having a thickness of 300 nm to 10 μm on a substrate; The step of nitriding a thin layer to form a coating containing at least one metal nitride or oxynitride. Regarding methods including

[0019] In certain implementations, the step of nitriding the deposited layer is insufficient for producing oxynitrides of the coating material.

[0020] In a particular implementation, during the deposition step, the deposited thin layer is TaO xIt is made by, and the nitriding step is performed such that the coating is made of tantalum nitride Ta having a stoichiometric composition substantially close to or equal to orthorhombic Ta3N5 so that the coating has a red color.

[0021] In a specific implementation, during the deposition step, the deposited thin layer is TaO x It is made by and combined with at least one metal element selected from Ba, Ca, Nd, La, Sr, Eu or Yb.

[0022] In a specific implementation, the nitriding step is performed at a temperature of 600 °C to 1200 °C for 10 hours to 60 hours, preferably at a temperature of 700 °C to 1000 °C for 20 hours to 50 hours, in a suitable atmosphere.

[0023] In a specific implementation, the nitriding step is performed at a temperature of 900 °C for 40 hours, in a suitable atmosphere.

Brief Description of the Drawings

[0024] Other features and advantages of the present invention will become apparent from the following detailed description given as a non-limiting example, with reference to the accompanying FIG. 1. [Figure 1] A cross-sectional view of an exterior component according to a preferred embodiment of the present invention is schematically shown.

[0025] Note that the figures are not necessarily drawn to scale for clarity.

Modes for Carrying Out the Invention

[0026] As schematically shown in FIG. 1, the present invention relates to an exterior component 10 of a watch or jewelry, comprising a substrate 11, and a coating 12 containing a metal nitride or oxynitride extending over a visible surface of the substrate 11. The coating 12 has a predetermined color depending on the metal constituting the coating 12, as will be described later in this specification.

[0027] The coating 12 is thick enough for its color to saturate, but at the same time, it is thin enough not to obscure the surface structure of the substrate 11 or affect the fit of the exterior components 10. For this reason, the thickness of the coating 12 is 300 nm to 10 μm, preferably 1 μm to 3 μm. More preferably, the thickness of the coating 12 is 2 μm.

[0028] The material constituting the substrate 11 is advantageously selected to withstand the conditions for deposition of the metal oxide layer and nitridation of the layer, as will be described in more detail below.

[0029] For example, the substrate 11 may be made of a ceramic material such as zirconia or sapphire, or a metal alloy such as stainless steel, or it may be made of silicon.

[0030] Advantageously, the exterior component 10 may include a bonding layer 13 made of Ti, Cr, or other suitable metals known to those skilled in the art, interposed between the substrate 11 and the coating 12. The bonding layer 13 has a thickness of 20 nm to 500 nm, preferably 100 nm.

[0031] In a preferred exemplary embodiment of the present invention, the coating 12 is made of tantalum nitride that is chemically and structurally substantially close to or equivalent to orthorhombic Ta3N5. This metallic nitride has a bright red, i.e., saturated color, defined by the following coordinates in the CieLAB color space in the reflection mode of the standard light source D65, when the observer is at 10° and with or without specular reflection (SCI, measured geometry di:8°). [Table 1]

[0032] When the material constituting the substrate 11 is sapphire, the coating 12 can be observed directly, i.e., with the coating 12 positioned between the observer and the substrate 11, or it can be observed indirectly, i.e., with the substrate 11 positioned between the observer and the coating 12, and therefore the latter is observed through the substrate 11. In the case of the use of the present invention where the coating 12 is observed indirectly, it should be noted that the exterior component 10 does not include a bonding layer 13 so as not to reduce the perception of the color of the coating 12.

[0033] The upper table shows the color coordinates of coating 12 under direct observation, and the lower table shows the color coordinates of coating 12 under indirect observation. [Table 2]

[0034] The bright red color of the coating 12 deposited on the sapphire substrate 11 can be characterized by the values ​​L*=42, a*=58, and b*=72 obtained during a colorimetric quantitative measurement in transmission mode of a standard light source D65 with the observer at 10° and the measurement geometry d:0°. Preferably, it is desirable to obtain a red color where the coordinates a* and b* are greater than 20, preferably greater than 50. More specifically, it is desirable to obtain a red color with coordinates L*=[30;50], a*=[50;70], and b*=[60;80].

[0035] In another exemplary embodiment of the present invention, the coating 12 can be formed from an AB(O,N) type composition in which A is a metallic element and B is tantalum Ta. This feature allows for the selection of different colored metal oxynitrides so that the coating 12 can have a wide variety of colors.

[0036] In the examples, the metal element A is selected from Ba, Ca, Nd, La, Sr, Eu, and Yb. Thus, the coating 12 can be formed to have a composition substantially close to or equal to that of BaTaO2N having a dark red or brown color, CaTaO2N having a green or yellow color, NdTaO2N having a red or brown color, SrTaO2N having an orange color, LaTaO2N having a red or orange color, EuTaO2N having a brown color, or Yb2Ta2O5N2 having a green color.

[0037] The present invention also relates to a method for manufacturing exterior components 10 for watches or jewelry, such as those described above.

[0038] The method includes the step of depositing a thin layer containing a metal oxide onto a substrate 11 such that the thin layer has a thickness selected between 300 nm and 10 μm. This deposition step is followed by the step of nitriding the thin layer to form a metal nitride or oxynitride coating 12.

[0039] Preferably, the deposited thin layer is TaO x It is made by. In detail, in this preferred embodiment, the deposition step is carried out by performing a PVD deposition method using a tantalum Ta target and a reactive gas consisting of O2. In detail, the thin layer can be deposited by cathode sputtering, vapor-phase electron beam deposition, arc deposition or pulsed laser beam ablation.

[0040] Therefore, at the end of the deposition step, the deposited thin layer is TaO x The nitriding step is performed so that the coating 12 is made of red Ta3N5.

[0041] More specifically, the nitriding step consists of exposing a thin layer to a suitable atmosphere, such as that resulting from the thermal decomposition of ammonia, for several hours in a furnace enclosure heated to several hundred degrees Celsius. More specifically, the nitriding step is carried out at a temperature of 600°C to 1200°C for 10 to 60 hours, preferably at a temperature of 700°C to 1000°C for 20 to 50 hours. In the most preferred embodiment, the nitriding step is carried out at a temperature of 900°C for 40 hours. For example, during the nitriding step, the flow rate of ammonia decomposed in the furnace enclosure is 200 ml / min.

[0042] In one variation of the method, nitriding of the deposited layer is not sufficient to produce oxynitrides of the coating material 12.

[0043] Furthermore, during the thin-layer deposition step, thin layers can be deposited from several different metal sources or alloy metal sources so that at the end of the nitriding step, the coating 12 contains an AB(O,N) type composition in which A is a metallic element and B is tantalum Ta.

[0044] The manufacturing method may, advantageously, include a step of depositing the bonding layer 13 as described above before carrying out the step of depositing the coating 12, for example by CVD, ALD, or PVD deposition. Advantageously, the bonding layer 13 deposition step and the coating 12 deposition step can be carried out sequentially within the same deposition enclosure, and the pressure within the enclosure is maintained between the two depositions. These deposition steps require at least two different material sources, one of which is intended to be used to form the bonding layer 13 on the substrate 11, and the other material source is intended to be used to form the coating 12 on the bonding layer 13.

[0045] More generally, it should be noted that the above-described implementations and embodiments are described as non-limiting examples and are therefore capable of other modifications.

[0046] In detail, it is possible to selectively structure a thin layer over its entire thickness before or after the nitriding step to form a specific decoration. Such steps can be performed using methods such as photolithography or laser ablation.

[0047] For the same purpose, it is also possible to perform a preliminary step of structuring the surface of the substrate 11.

Claims

1. A watch or jewelry exterior component (10), the exterior component (10) comprises a substrate (11), and a single layer coating (12) containing a tantalum Ta-based nitride or tantalum Ta-based oxynitride having a thickness of 300 nm to 10 μm and having a predetermined saturated color is spread on the surface of the substrate (11). The coating (12) is made of tantalum nitride whose stoichiometric composition is substantially close to or equal to orthorhombic Ta3N5, and is the exterior component (10).

2. The exterior part (10) according to claim 1, wherein the coating (12) has a thickness of 1 μm to 3 μm.

3. The exterior part (10) according to claim 2, wherein the coating (12) has a thickness equal to 2 μm.

4. A watch or jewelry exterior part (10), wherein the exterior part (10) comprises a substrate (11), and a single layer coating (12) containing a tantalum Ta-based nitride or tantalum Ta-based oxynitride having a thickness of 300 nm to 10 μm so as to have a predetermined saturated color is spread on the surface of the substrate (11). The coating is produced by adding oxygen in the range of 0 to 5 atomic percent to the exterior component (10).

5. A watch or jewelry exterior part (10), wherein the exterior part (10) comprises a substrate (11), and a single layer coating (12) containing a tantalum Ta-based nitride or tantalum Ta-based oxynitride having a thickness of 300 nm to 10 μm so as to have a predetermined saturated color is spread on the surface of the substrate (11). The coating (12) forms an AB(O,N) type composition in which B is tantalum Ta and A is a metallic element selected from Ba, Ca, Nd, La, Sr, Eu, and Yb, and is used for the exterior part (10).

6. The coating (12) is BaTaO 2 N, CaTaO 2 N, NdTaO 2 N, LaTaO 2 N, SrTaO 2 N, EuTaO 2 N or Yb 2 Ta 2 O 5 N 2 The exterior component (10) according to claim 5, made of

7. A manufacturing method for producing exterior parts (10) of a watch or jewelry, - A step of depositing a thin layer of tantalum Ta-based metal oxide having a thickness of 300 nm to 10 μm on a substrate (11), - A step of nitriding the thin layer in order to form a single layer coating (12) containing a tantalum Ta-based nitride or tantalum Ta-based oxynitride having a predetermined saturated color. A manufacturing method that includes this.

8. During the aforementioned deposition step, the deposited thin layer is TaO x The nitriding step is performed so that the stoichiometric composition is substantially orthorhombic Ta 3 N 5 The manufacturing method according to claim 7, wherein the coating (12) is made of tantalum nitride equal to .

9. During the aforementioned deposition step, the deposited thin layer is TaO x The manufacturing method according to claim 7, which is made of and combined with at least one metallic element selected from Ba, Sr, Ca, Nd, La, Eu, or Yb.

10. The manufacturing method according to claim 7, wherein the nitriding step is carried out at a temperature of 600°C to 1200°C for 10 to 60 hours.

11. The manufacturing method according to claim 10, wherein the nitriding step is carried out at a temperature of 900°C for 40 hours.

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