Trim part for timepieces, jewellery or fashion articles comprising layers of titanium oxide

Abstract

The invention relates to a method for decorating a watch, jewelry or fashion item component (10), comprising the steps of: - forming a first interference layer (110) of titanium oxide on the whole of a decorative face (101) of a titanium substrate (100), by anodizing said decorative face (101) at a voltage V1, - machining a portion of the first interference layer (110) so as to form at least one opening (111) leading to a portion of the decorative face (101), - forming a second interference layer (120) of titanium oxide by anodizing said portion at a voltage V2 lower than the voltage V1.

Description

Technical field of the invention

[0001] The invention falls within the field of watch parts, jewelry or fashion articles.

[0002] More specifically, the invention relates to a method for decorating a component. This method is advantageously applicable to any component in the fields of watchmaking, jewelry, fashion items such as leather goods, eyewear, writing instruments, or portable electronic devices.

[0003] More specifically, in the watchmaking field, a case component can consist of a dial, a mainplate, a bridge, a gear train, an oscillating weight, a bezel, a case middle, a link or other bracelet part or any other visible component of a watch. Technological background

[0004] In the watchmaking, jewelry and fashion industries, economic players are constantly looking for new decoration solutions to modify the appearance of their products in order to increase their attractiveness or to differentiate themselves from the competition.

[0005] For example, in the watchmaking industry in particular, it is common practice to color watch parts by spraying a varnish. However, these varnishes can mask any decorations achieved through surface structuring, such as sunburst finishing.

[0006] It is also known to color trim pieces using vacuum-based thin-film deposition methods. However, these deposition methods have the drawback of coloring the trim piece uniformly, thus limiting decoration possibilities or making them more complex to implement. Furthermore, these deposition methods are relatively expensive.

[0007] The invention addresses the need to colorize a garment with multiple colors while overcoming the aforementioned drawbacks. Summary of the invention

[0008] The invention achieves the aforementioned objective and relates to a method for decorating a component of a watch, jewelry, or fashion item, comprising the steps of: formation of a first interference layer of titanium oxide on the whole of a decorative face of a titanium substrate, by anodizing said decorative face at a voltage V1, machining of a portion of the first interference layer so as to form at least one opening leading to a portion of the decorative face, formation of a second interference layer of titanium oxide by anodizing said portion at a voltage V2 lower than the voltage V1.

[0009] One of the advantages of the present invention is that it preserves the appearance of the topography of the decorative face of the body of the trim piece. In other words, any decorations created by surface structuring on the decorative face of the body of the trim piece remain visible due to the thinness of the decorative layer.

[0010] The present invention also makes it possible to colour a garment without adding a colouring agent.

[0011] Furthermore, thanks to the present invention, it is possible to colorize the dressing piece according to a wide choice of colors.

[0012] In particular embodiments, the invention may further comprise one or more of the following features, taken individually or in all technically possible combinations.

[0013] In specific implementation modes, the voltages V1 and V2 are between 1 and 150 volts and are applied for 1 to 10 minutes, or even between 2 and 5 minutes.

[0014] In specific implementation modes, the first interference layer has a maximum thickness of 200 nm and the second interference layer has a minimum thickness of 1 nm.

[0015] In particular implementation methods, machining is carried out in such a way as to generate a gradient of material removal in the plane in which the decorative face extends.

[0016] In particular modes of implementation, following the step of forming the second interfering layer of titanium oxide, an additional machining step of a portion of the first interfering layer and / or a portion of the second interfering layer is carried out so as to form at least one additional opening leading to a portion of the decorative face, followed by a step of forming an additional interfering layer by anodizing at a voltage V3 lower than the voltage V2.

[0017] According to another aspect, the present invention relates to a watch, jewelry or fashion item component comprising a titanium substrate having a decorative face on a first portion of which extends a first interfering layer of titanium oxide, and on a second portion of which extends a second interfering layer of titanium oxide, the first interfering layer and the second interfering layer being contiguous and having different thicknesses from each other. Brief description of the figures

[0018] Other features and advantages of the invention will become apparent from the following detailed description, given by way of non-limiting example, with reference to the drawings in which: THE figures 1 to 3 schematically represent successive stages in the implementation of the decoration process according to an example of an embodiment of the invention, The figure 4represents a front view of a decorative trim piece produced by the process shown in steps 1 to 3, the figures 5 and 6 schematically represent additional steps according to another example of implementing the decoration process according to the invention, following the steps shown on the figures 1 to 3 , there figure 7 schematically represents a front view of a trim piece decorated by the implementation of the process represented by steps 1 to 3, 5 and 6.

[0019] Note that the figures are not drawn to scale for reasons of clarity. Detailed description of the invention

[0020] One aspect of the present invention relates to a watch, jewelry or fashion accessory component 10 comprising a titanium substrate 100 having a decorative face 101. A first interference layer 110 of titanium oxide extends over a first portion of the decorative face 101, and a second interference layer 120 of titanium oxide extends over a second portion of said face.

[0021] Advantageously, the first interference layer 110 and the second interference layer 120 are contiguous and have different thicknesses from each other, so that the decorative face 101 has two different interference colors.

[0022] The present invention also relates to a method of decorating such a trim piece 10 to obtain the aforementioned interference colors.

[0023] Preferably, and as represented on the figures 3, 4 and 6, 7In examples of embodiments of the invention, the casing 10 is a watch dial and therefore has a disc-shaped body. Preferably, the body of the casing 10 is made entirely of titanium and forms the substrate 100. Alternatively, the body may have a titanium layer several tenths of a millimeter or several millimeters thick, forming the substrate 100.

[0024] In this text, the term "titanium" refers to pure titanium and titanium alloys.

[0025] The process according to the invention comprises a step of forming the first interference layer 110 of titanium oxide on the entire decorative face 101 of the substrate 100, by anodizing said decorative face 101 at a voltage V1. This step is schematically represented in the figure 1 .

[0026] Anodizing is carried out, in a manner known to those skilled in the art, in an acidic or basic electrolytic bath, at a constant regulated temperature, by application of an electric current and a predefined electric voltage.

[0027] The bath may consist of sulfuric, phosphoric, or oxalic acid, or a mixture of these acids. Alternatively, the bath may consist of sodium silicates, potassium hydroxide, sodium hydroxide, or a mixture of these alkaline solutions. The concentrations of the acid(s) or basic solution(s) in the electrolytic bath are within the capabilities of a person skilled in the art.

[0028] A machining step is then carried out on a portion of the first interference layer 110 to form at least one opening 111 leading to a portion of the decorative face 101. The machining is therefore performed throughout the entire thickness of the first interference layer 110, as can be seen on the figure 2 In other words, the machining can be carried out in such a way as to remove only the first interference layer 110 or to remove the first interference layer 110 and part of the substrate 100, by cutting a pocket in said substrate 100.

[0029] It should be noted that, in this text, the term "machining" refers to any operation involving the removal of material.

[0030] Such a machining step can therefore be implemented by any suitable material removal technique, for example, by laser machining, in particular by selective laser ablation, by mechanical machining, in particular by cutting tools or by sandblasting, by chemical machining or by photolithography.

[0031] The second interference layer 120 of titanium oxide is then formed on the portion of the decorative face 101 exposed during the machining step, by anodizing at a voltage V2 lower than the voltage V1, as visible on the figure 3 .

[0032] Thus, the second interference layer 120 is thinner than the first interference layer 110, and consequently, the first and second interference layers 110 and 120 have different colors. The interference phenomenon itself is well known to those skilled in the art and is therefore not described in this text.

[0033] Advantageously, the thickness of the first interference layer 110 does not vary during the formation of the second interference layer 120, as long as the voltage V2 is less than the voltage V1.

[0034] The decoration created by combining the first and second interference layers 110 and 120 is therefore defined by the pattern according to which the first interference layer 110 is machined. It is thus possible to easily produce rich and varied decorations featuring at least two different colors. As an example, the first interference layer 110 can be machined according to a material removal gradient, as schematically represented in Figures 2 and 3, so as to generate a color gradient, as schematically represented in Figures 2 and 3. figures 4 and 7 .

[0035] More precisely, the material removal gradient is carried out in the plane in which the decorative face extends and is characterized by an evolution of the presence of material from the first interference layer 110 on the decorative face 101 along one or more given directions. In particular, on the figures 4 and 7, the material gradient extends radially, the material of the first interference layer 110 totally covering the decorative face at the center of the covering piece 10, then covering less and less surface of the decorative face 101 as it is further away from the center of the covering piece 10. The second interference layer 120 being formed on the portion of the decorative face 101 uncovered during the machining step, its distribution on the decorative face corresponds to the inverse of that of the first layer 110, the junction between these two layers has a blended appearance, and consequently the colors of the first and second interference layers 110 and 120 have a gradient appearance.

[0036] Such machining can be carried out by laser, sandblasting, sunblasting, grinding or any other material removal technique mentioned above in the text.

[0037] As an example, the voltages V1 and V2 applied during the formation of the first and second interference layers 110 and 120 respectively are between 1 and 150 volts, and are applied for 1 to 10 minutes, or even between 2 and 5 minutes.

[0038] The values ​​of the applied voltage for the first and second interference layers 110 and 120 are determined according to the nature of the electrolytic bath and according to the desired color for each of said layers.

[0039] For example, the first interference layer 110 can have a maximum thickness of 200 nm and the second interference layer 120 can have a minimum thickness of 1 nm. As an example, the second interference layer 120 is 5 nm thinner than the first interference layer 110.

[0040] It should be noted that the parameters used to modify the thickness of the interference layers formed by anodizing are the applied voltage and the composition of the electrolytic bath. Therefore, it is necessary to vary at least one of these parameters to obtain an interference layer of the desired thickness and color.

[0041] In particular, one of the interference layers can be produced by applying a voltage of 50 volts for 3 minutes during anodizing in an acidic electrolytic bath, for example a 200 g / L sulfuric acid bath. The resulting layer has a thickness of approximately 80 nm and a light blue color.

[0042] Furthermore, one of the interference layers can be produced by applying a voltage of 40 volts for 3 minutes during anodizing in an acidic electrolytic bath, for example, a 200 g / L sulfuric acid bath. The resulting layer has a thickness of approximately 60 nm and a blue color.

[0043] In yet another example, one of the interference layers can be produced by applying a voltage of 20 volts for 3 minutes during anodizing in an acidic electrolytic bath, for example, a 200 g / L sulfuric acid bath. The resulting layer has a thickness of approximately 35 nm and a violet color.

[0044] In examples of implementations of the present invention, following the step of forming the second interference layer 120 of titanium oxide, the process may include an additional step of machining a portion of the first interference layer 110 and / or a portion of the second interference layer 120. This additional machining step is carried out so as to form at least one additional opening 121 leading to a portion of the decorative face 101, as shown in the figure 5 The machining can be carried out so as to extend only through the first interference layer 110 and / or the second interference layer 120, or so as to extend also into a part of the substrate 100, by cutting a pocket in said substrate 100, as visible in the figure 5The additional machining step can be carried out so as to generate a material removal gradient in the plane in which the decorative face 101 extends, for example in addition to a possible formation of a gradient during the machining step of a portion of the first interference layer 110.

[0045] As illustrated on the figure 6 This additional machining step is followed by a step of forming an additional interference layer 130 by anodizing at a voltage V3 lower than the voltage V2. Thus, the trim piece 10 can be decorated to have three colors.

[0046] It is understood that the process according to the invention can comprise as many machining steps followed by steps for forming an interference layer as desired, it being understood that the anodizing tension of a layer must be lower than that applied for the formation of the preceding layer. In light of the foregoing, it is understood that each machining step can be carried out or not in such a way as to generate a material removal gradient in the plane in which the decorative face 101 extends.

[0047] Furthermore, once the interference layers have formed, they can be protected by a transparent protective layer, for example, applied by a vacuum deposition method such as physical vapor deposition or chemical vapor deposition. Alternatively, the protective layer can be a varnish layer, for example, a cellulose-based varnish such as Zapon, an acrylic or epoxy varnish, for example, with a thickness between 3 and 20 µm, or it can be a lacquer layer with a thickness between 100 and 500 µm.

[0048] More generally, it should be noted that the implementation variants considered above have been described as non-limiting examples, and that other variants are therefore conceivable.

[0049] Naturally, the process may include a preliminary step, i.e. before the step of forming a first interference layer 110, consisting of preparing the decorative face 101 by standard surface structuring processes, for example of Geneva coast type, sunburst, sandblasting, polishing, etc.

Claims

1. A method for decorating a component (10) of a watch, jewelry, or fashion item, characterized in that It includes the steps of: - formation of a first interference layer (110) of titanium oxide on the whole of a decorative face (101) of a titanium substrate (100), by anodizing said decorative face (101) at a voltage V1, - machining of a portion of the first interference layer (110) so as to form at least one opening (111) leading to a portion of the decorative face (101), - formation of a second interference layer (120) of titanium oxide by anodizing said portion at a voltage V2 lower than the voltage V1.

2. Method according to claim 1, wherein the voltages V1 and V2 are between 1 and 150 volts and are applied for 1 to 10 minutes, or even between 2 and 5 minutes.

3. A method according to any one of claims 1 or 2, wherein the first interference layer (110) has a maximum thickness of 200 nm and the second interference layer (120) has a minimum thickness of 1 nm.

4. A method according to any one of claims 1 to 3, wherein the machining is carried out so as to generate a gradient of material removal in the plane in which the decorative face extends.

5. A method according to any one of claims 1 to 4, wherein following the step of forming the second interference layer (120) of titanium oxide, an additional step of machining a portion of the first interference layer (110) and / or a portion of the second interference layer (120) is carried out so as to form at least one additional opening (121) leading to a portion of the decorative face (101), followed by a step of forming an additional interference layer (130) by anodizing at a voltage V3 lower than the voltage V2.

6. Watch, jewelry or fashion item component (10) comprising a titanium substrate (100) having a decorative face (101) on a first portion of which extends a first interference layer (110) of titanium oxide, and on a second portion of which extends a second interference layer (120) of titanium oxide, the first interference layer (110) and the second interference layer (120) being contiguous and having different thicknesses from each other.

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