Outer part of timepiece, jewelry or fashion accessory comprising layer of titanium oxide
By forming first and second interference layers of titanium oxide on a titanium substrate, a variety of colors can be generated by utilizing the thickness difference, solving the problems of uniform coloring and high cost of external parts of watches, jewelry and fashion accessories, and achieving multi-color decorative effects and structural preservation.
Patent Information
- Application Number
- CN202510975856.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-07-17
- Filing Date
- 2025-07-15
- Publication Date
- 2026-01-20
AI Technical Summary
Existing technologies in the fields of watches, jewelry and fashion accessories have problems with coloring external parts, such as uniform coloring or high complexity, and traditional methods are also costly.
A first interference layer of titanium oxide is formed by anodizing the decorative surface of the titanium substrate under voltage V1, and then a portion of it is processed under voltage V2 to form a second interference layer of titanium oxide. The thickness difference between the two layers is used to produce a variety of color effects while preserving the physical characteristics of the decorative surface.
It achieves multi-color coloring effects for external components while maintaining the structural features of the decorative surface, avoiding the shortcomings of traditional methods and reducing costs.
Smart Images
Figure CN121363028A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present invention relates to the field of horology, jewelry or fashion accessories.
[0002] More particularly, the present invention relates to a method of decorating an external component. This method can advantageously be applied to any external component in the field of horology, jewelry, fashion accessories, such as leather goods, eyewear, writing instruments or portable electronic devices.
[0003] More particularly, in the field of horology, the external component can comprise a dial, a main plate, a bar, a train, a balance wheel, a bezel, a middle, a link or other part of a bracelet or any other visible assembly of a watch. TECHNICAL BACKGROUND
[0004] In the field of horology, jewelry and fashion accessories, market players are constantly seeking new decoration solutions to change the appearance of their products, to enhance the attractiveness of the products or to stand out in the competition.
[0005] For example, in particular in the field of horology, external components are usually colored by means of a varnish sprayed. However, these varnishes mask any decorative effect created by the structuring of the surface, such as sunray brushing.
[0006] Thin film vacuum deposition methods are also used to color external components. However, the drawback of such deposition methods is that the external component is uniformly colored, thereby limiting the decorative possibilities or making their use more complex. Furthermore, these deposition methods are relatively expensive.
[0007] The present invention solves the need to color an external component with several colors, without the aforementioned drawbacks. SUMMARY
[0008] The present invention achieves the aforementioned objectives and therefore relates to a method of decorating an external component of a timepiece, jewelry or fashion accessory, comprising the following steps:
[0009] - forming a first interference layer of titanium oxide on the decoration face of the titanium substrate by anodizing the entire decoration face at a voltage VI,
[0010] - machining a portion of the first interference layer to form at least one opening giving access to a portion of the decoration face,
[0011] - forming a second interference layer of titanium oxide by anodizing said portion at a voltage V2 lower than the voltage VI.
[0012] One of the advantages of the present application is that the appearance of the physical features on the decorative face of the body of the exterior part is preserved. In other words, since the thickness of the thin decorative layer is minimal, any decoration formed by surface structuring on the decorative face of the body of the exterior part remains visible.
[0013] The present application also makes it possible to colour the exterior part without adding a colouring agent.
[0014] Furthermore, the present application makes it possible to colour the exterior part in a plurality of colours.
[0015] In particular embodiments, the present application can also include one or more of the following features, taken alone or in any technically possible combination.
[0016] In particular embodiments, the voltages VI and V2 are between 1 and 150 volts, and are applied for between 1 and 10 minutes, or even between 2 and 5 minutes.
[0017] In particular embodiments, the maximum thickness of the first interference layer is 200 nm, and the minimum thickness of the second interference layer is 1 nm.
[0018] In particular embodiments, the machining is performed so as to create a gradient of material removal in the plane in which the decorative face extends.
[0019] In particular embodiments, after the step of forming the second interference layer of titanium oxide, an additional step of machining a portion of the first interference layer and / or a portion of the second interference layer is performed, 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 interference layer by anodization at a voltage V3 lower than the voltage V2.
[0020] According to another aspect, the present application relates to an exterior part for a watch, a piece of jewelry or a fashion accessory, comprising a titanium substrate having a decorative face, the decorative face having a first interference layer of titanium oxide extending over a first portion of the decorative face, and a second interference layer of titanium oxide extending over a second portion of the decorative face, the first interference layer and the second interference layer being adjacent and each having a different thickness. BRIEF DESCRIPTION OF DRAWINGS
[0021] Other characteristics and advantages of the present application will become apparent from the following detailed description, given by way of non-limiting example, and with reference to the drawings, in which:
[0022] - Figures 1 to 3 The successive steps involved in the decoration method according to an exemplary embodiment of the present application are schematically illustrated, in which Figure 3 is a cross-section A-A.
[0023] - Figure 4 A front view of an exterior part decorated using the method illustrated in steps 1 to 3 is shown,
[0024] - Figure 5 and Figure 6 The additional steps of another exemplary embodiment of the decoration method according to the application are schematically illustrated, which are subsequent to the steps shown in Figures 1 to 3 wherein Figure 6 is a cross section B-B,
[0025] - Figure 7 A front view of an exterior part decorated with the method shown in steps 1 to 3, 5 and 6 is schematically illustrated.
[0026] It should be noted that these figures are not drawn to scale for the sake of clarity. DETAILED DESCRIPTION
[0027] One aspect of the application relates to an exterior part 10 for a watch, a jewelry or a fashion accessory, comprising a titanium base material 100 having a decorated face 101. A first interference layer 110 of titanium oxide extends on a first portion of the decorated face 101 and a second interference layer 120 of titanium oxide extends on a second portion of said decorated face.
[0028] Advantageously, the first interference layer 110 and the second interference layer 120 are adjacent and each have a different thickness, so that the decorated face 101 has two different interference colors.
[0029] The application also relates to a method of decorating such an exterior part 10 to obtain the aforementioned interference colors.
[0030] Preferably, as Figure 3 , 4 and 6, 7, in an exemplary embodiment of the application, the exterior part 10 is a watch dial, thus having a disc-shaped body. Preferably, the body of the exterior part 10 is entirely made of titanium and forms the base material 100. Alternatively, the body can have a titanium layer having a thickness of a few tenths of a millimeter or a few millimeters, forming the base material 100.
[0031] In the present text, the term "titanium" refers to pure titanium and titanium alloys.
[0032] The method according to the application comprises the step of forming a first interference layer 110 of titanium oxide on the entire decorated face 101 of the base material 100 by anodizing said decorated face 101 at a voltage VI. This step is schematically illustrated in Figure 1 .
[0033] The anodizing is performed in a manner known to the person skilled in the art by applying an electric current and a predetermined voltage at a constant, controlled temperature in an acidic or basic electrolytic bath.
[0034] The bath can consist of sulfuric acid, phosphoric acid or oxalic acid or a mixture of these acids. Alternatively, the bath can consist of sodium silicate, potassium hydroxide, sodium hydroxide or a mixture of these alkaline solutions. The concentration of the acid or acid(s) or alkaline solution or alkaline solutions in the electrolytic bath can be determined by the person skilled in the art.
[0035] Then, a machining step is performed 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. Thus, the machining is performed through the entire thickness of the first interference layer 110, as Figure 2 illustrated. In other words, the machining can be performed to remove only the first interference layer 110, or to remove the first interference layer 110 and part of the substrate 100, thus hollowing out a pocket in said substrate 100.
[0036] It is to be noted that, in the present text, the term "machining" refers to any operation involving the removal of material.
[0037] Thus, such a machining step can be performed by any suitable material removal technique, for example by laser machining, in particular by selective laser ablation, by mechanical machining, in particular with a cutting tool or by sandblasting, by chemical machining or by photolithography.
[0038] Then, a second interference layer 120 of titanium oxide is formed on the portion of the decorative face 101 exposed during the machining step, by anodization at a voltage V2 lower than the voltage VI, as Figure 3 illustrated.
[0039] Thus, the second interference layer 120 is thinner than the first interference layer 110, resulting in the first interference layer 110 and the second interference layer 120 having different colors. The interference phenomenon itself is well known to the person skilled in the art, and will thus not be described here in more detail.
[0040] Advantageously, as long as the voltage V2 is lower than the voltage VI, the thickness of the first interference layer 110 does not change when the second interference layer 120 is formed.
[0041] Thus, the decoration resulting from the combination of the first interference layer 110 and the second interference layer 120 is defined by the pattern in which the first interference layer 110 is machined. This makes it possible to easily create a rich variety of decorations in at least two different colors. As an exemplary embodiment, the first interference layer 110 can be machined using a material removal gradient (as Figure 2 and 3 schematically illustrated), resulting in a color gradient (as Figure 4 and 7 schematically illustrated).
[0042] More specifically, the material removal gradient is generated in the plane in which the decorative surface extends, characterized by the fact that the presence of the material of the first interference layer 110 on the decorative surface 101 varies in one or more given directions. In particular, in Figure 4 and Figure 7 the material gradient extends radially, the material of the first interference layer 110 completely covering the decorative surface at the center of the outer part 10, then increasingly less and less as it moves away from the center of the outer part 10. Since the second interference layer 120 is formed on the portion of the decorative surface 101 exposed during the machining step, its distribution on the decorative surface is inversely proportional to that of the first interference layer 110. The junction between the two layers has a melted appearance, so the colors of the first interference layer 110 and of the second interference layer 120 have a gradient appearance.
[0043] This type of machining can be carried out using a laser, sandblasting, sunburst polishing, grinding or any other material removal technique mentioned previously herein.
[0044] For example, the voltage VI and V2 applied to form the first interference layer 110 and the second interference layer 120 is between 1 and 150 volts, and the application time is between 1 and 10 minutes, or even between 2 and 5 minutes.
[0045] The voltage value applied to the first interference layer 110 and to the second interference layer 120 is determined according to the type of electrolytic bath and the desired color of each layer.
[0046] For example, the maximum thickness of the first interference layer 110 can be 200 nm, and the minimum thickness of the second interference layer 120 can be 1 nm. For example, the second interference layer 120 is 5 nm thinner than the first interference layer 110.
[0047] It should be noted that the parameters that can be varied to change the thickness of the interference layer formed by anodization are the voltage value applied and the composition of the electrolytic chemical bath. Therefore, at least one of these parameters needs to be varied to obtain an interference layer of the desired thickness, and therefore with the desired color.
[0048] In particular, one of the interference layers can be prepared by applying a voltage of 50 volts for 3 minutes during anodization in an acid electrolytic bath, for example a 200 g / L sulfuric acid bath. The resulting layer has a thickness of approximately 80 nm and a color that is light blue.
[0049] Alternatively, one of the interference layers can be prepared by applying a voltage of 40 volts for 3 minutes during anodization in an acid electrolytic bath, for example a 200 g / L sulfuric acid bath. The resulting layer has a thickness of approximately 60 nm and a color that is blue.
[0050] In another example, one of the interference layers can be prepared by anodization during 3 minutes with an applied voltage of 20 volts in an acidic electrolytic bath, for example a 200 g / L sulfuric acid bath. The resulting layer has a thickness of about 35 nm and a color that is purple.
[0051] In an exemplary embodiment of the application, after the step of forming the second interference layer of titanium oxide 120, the method can comprise 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 performed to form at least one additional opening 121 to a portion of the decorative face 101, as shown in Figure 5 The machining can be performed so as to extend only through the first interference layer 110 and / or the second interference layer 120, or also into a portion of the substrate 100, thus hollowing out a pocket in said substrate 100, as shown in Figure 5 The additional machining step can be performed so as to create a gradient of material removal in the plane in which the decorative face 101 extends, for example in addition to any gradient formed in the step of machining a portion of the first interference layer 110.
[0052] As shown in Figure 6 The additional machining step is followed by a step of forming an additional interference layer 130 by anodization at a voltage V3 lower than the voltage V2. The outer part 10 can thus be decorated with three colors.
[0053] Of course, the method according to the application can comprise any number of machining steps, followed by a step of forming a desired interference layer, it being understood that the anodization voltage of the layer must be lower than the voltage applied to form the preceding layer. In summary, it is clear that each machining step can or can not be performed to create a gradient of material removal in the plane in which the decorative face 101 extends.
[0054] Furthermore, once the interference layers have been formed, they can be protected by a transparent protective layer applied by a vacuum deposition method, for example physical vapor deposition or chemical vapor deposition. The protective layer can also be a varnish layer, for example a cellulose-based varnish (for example zapon), an acrylic or epoxy varnish, for example with a thickness of 3 to 20 pm, or can be a lacquer layer, with a thickness of 100 to 500 pm.
[0055] More generally, it should be noted that the variant embodiments considered above have been described by way of non-limiting examples, and that other variants can thus be envisaged.
[0056] Of course, the method can comprise preliminary steps, in other words steps preceding the step of forming the first interference layer 110, comprising the preparation of the decorative face 101 by conventional surface structuring methods, for example Geneva ripples, sunburst polishing, sandblasting, polishing, etc.
Claims
1. A method for decorating the exterior parts (10) of clocks, jewelry, or fashion accessories, characterized in that, Includes the following steps: -A first interference layer (110) of titanium oxide is formed on the decorative surface (101) by anodizing the entire decorative surface (101) of the titanium substrate (100) under voltage V1. - A portion of the first interference layer (110) is processed to form at least one opening (111) leading to a portion of the decorative surface (101), the processing being performed to create a material removal gradient in the plane extending from the decorative surface. - A second interference layer (120) of titanium oxide is formed by anodizing the portion at a voltage V2 lower than voltage V1.
2. The method of claim 1, wherein voltages V1 and V2 are 1 to 150 volts and are applied for 1 to 10 minutes, or even 2 to 5 minutes.
3. The method according to any one of claims 1 or 2, wherein the maximum thickness of the first interference layer (110) is 200 nm and the minimum thickness of the second interference layer (120) is 1 nm.
4. The method according to any one of claims 1 or 2, wherein, After the step of forming the second interference layer (120) of titanium oxide, an additional step is performed to process a portion of the first interference layer (110) and / or a portion of the second interference layer (120) to form at least one additional opening (121) leading to a portion of the decorative surface (101), and then a step of forming an additional interference layer (130) by anodizing at a voltage V3 below voltage V2 is performed.
5. An external component (10) for a watch, jewelry or fashion accessory, comprising a titanium substrate (100) having a decorative surface (101) having a first interference layer (110) of titanium oxide extending on a first portion of the decorative surface and a second interference layer (120) of titanium oxide extending on a second portion of the decorative surface, the first interference layer (110) and the second interference layer (120) being adjacent and having different thicknesses.