External part comprising an interferential layer coating deposited on a surface made of a material containing at least 50 wt % of aluminium

Abstract

The invention relates to an outer part (10) for use in a timepiece, jewelry or advanced jewelry, characterised in that it comprises a substrate (100) having a supporting surface (101) made of a material containing at least 50 mass% aluminum, on which a translucent thin-film dielectric coating (110) is deposited, said thin-film dielectric coating comprising at least two layers, wherein an end layer (112) made of TiO2 and a base layer (111) made of Al2O3 covering the support surface (101) are included.

Description

(19) State Intellectual Property Office (12) Invention Patent Application (10) Application Publication Number (43) Application Publication Date (21) Application Number 202511873303.9 (22) Application Date 2025.12.12 (30) Priority Data 24222587.8 2024.12.20 EP (71) Applicant Swatch Group Research and Development Ltd. Address Switzerland (72) Inventors C. Halle L. Kürsau M. Bodo G. Poli (74) Patent Agency Beijing Zhongzi Law Firm 11247 Patent Attorneys Lin Bainan Liu Jinhui (51) Int.Cl. G04D 3 / 00 (2006.01) C23C 16 / 40 (2006.01) (54) Title of Invention Includes an External Part with an Interference Layer Coating Deposited on a Surface Made of a Material Containing at Least 50% by Weight Aluminum (57) Abstract This invention relates to an external part (10) for use in watches, jewelry or fine jewelry, characterized in that the part comprises a substrate (100) having a support surface (101) made of a material containing at least 50% by weight aluminum, wherein a translucent thin film dielectric coating (110) is deposited on the support surface, the thin film dielectric coating comprising at least two layers, including an end layer (112) made of TiO2 and a base layer (111) made of Al2O3 covering the support surface (101). Claims 1 page, Description 3 pages, Drawings 1 page, CN 122260760 A 2026.06.23 CN 1 22 26 07 60 A 1. An external part (10) for use in watches, jewelry or fine jewelry, characterized in that the part comprises a substrate (100) having a support surface (101) made of a material containing at least 50% by mass aluminum, wherein a translucent thin film dielectric coating (110) is deposited on the support surface, the thin film dielectric coating comprising at least two layers, including an end layer (112) made of TiO2 and a base layer (111) made of Al2O3 covering the support surface (101). 2. The external part (10) according to claim 1, comprising an even number of intermediate layers (113), wherein at least two of the intermediate layers (113) are deposited between a base layer (111) and an end layer (112) and are alternately made of TiO2 and Al2O3, such that the intermediate layer (113) covering the base layer (111) is made of TiO2 and the layer in contact with the end layer (112) is made of Al2O3. 3. The external part (10) according to claim 1 or 2, wherein the substrate (100) is formed by an object made of pure aluminum or an aluminum alloy, and the object comprises a support surface (101).4. The external part (10) according to claim 1 or 2, wherein the substrate (100) comprises an object on which a coating made of aluminum nitride, aluminum carbide, aluminum oxide or aluminum carbonitride is formed, and the coating comprises a support surface (101). 5. The external part (10) according to claim 2, wherein the thin film dielectric coating (110) comprises four intermediate layers (113). 6. The external part (10) according to claim 5, wherein the thickness of the layers in the thin film dielectric coating (110) is selected to impart interference colors to the external part (10), which are characterized in CIELAB space in a reflection mode with a standard light source D65, an observation angle of 10° and a measurement geometry of di: 8° as parameters L* = [75; 85], a* = [-45; -35], b* = [5; 15]. 7. The external part (10) according to claim 6, wherein the base layer (111) has a thickness of 1 nm to 10 nm, the intermediate layer (113) has a thickness of 20 nm to 90 nm, and the end layer (112) has a thickness of 55 nm to 65 nm. 8. The external part (10) according to claim 7, wherein the intermediate layers (113) obtained continuously from the intermediate layer (113) closest to the base layer (111) to the intermediate layer (113) closest to the end layer (112) have thicknesses of 25 nm to 30 nm, 75 nm to 85 nm, 15 nm to 25 nm, and 15 nm to 25 nm, respectively. Claims 1 / 1 page 2 CN 122260760 A External part comprising an interference layer coating deposited on a surface made of a material containing at least 50% by weight aluminum Technical Field

[0001] The present invention relates to the field of watches, jewelry or fine jewelry, and more particularly to external parts for watches, jewelry or fine jewelry.

[0002] In this specification, as is generally understood in the aforementioned art, the term "external part" refers to a component that is visible to the user and has a decorative function, meaning that it contributes to the visual appearance of an article. Background Art

[0003] In the fields of watches, jewelry, and fine jewelry, there is always a search in the market for new decorative solutions to change the appearance of products, thereby increasing their appeal or distinguishing them from competitors.

[0004] For example, and particularly in the watchmaking field, vacuum deposition methods are commonly used to deposit thin layers on a substrate to color external parts, such as physical vapor deposition or chemical vapor deposition methods. However, depending on the nature of the substrate and the nature of the deposited layer, adhesion problems may occur. This disadvantage requires the deposition of an adhesive layer, which makes the coloring process of the part more complex.

[0005] Regarding external parts comprising a substrate made of aluminum, the above-mentioned disadvantages can be overcome by employing an anodized substrate to color the external parts.However, anodizing is a relatively long process because it requires a long cycle time to grow an oxide layer on the substrate and involves many steps. Furthermore, external parts must be processed between each step, which increases the risk of damage to the parts. Summary of the Invention

[0006] The present invention overcomes the above-mentioned disadvantages and relates to external parts for use in watches, jewelry, or fine jewelry, characterized in that the part comprises a substrate having a support surface made of a material containing at least 50% by mass aluminum, on which a thin film dielectric coating is deposited, the thin film dielectric coating comprising at least two layers, including an end layer made of TiO2 and a base layer made of Al2O3 covering the support surface.

[0007] Due to the chemical affinity between the support surface and the base layer, the present invention advantageously ensures excellent adhesion between the support surface and the thin film dielectric coating. These layers can also be used to impart bright and precise colors to external parts.

[0008] In addition, the present invention is an advantageous alternative to coloring aluminum substrates by anodizing processes and does not have the disadvantages associated with that process. In practice, these layers in the thin-film dielectric coating are deposited using a method known to those skilled in the art for depositing thin atomic layers, abbreviated as "ALD," which stands for "Atomic Layer Deposition." This allows for rapid and easy coloring of the aluminum substrate without the need to process external parts between each layer deposition.

[0009] In some embodiments, the invention may also include one or more of the following features, which may be independent of each other or as any technically possible combination.

[0010] In some embodiments, the external part comprises an even number of intermediate layers, wherein at least two of the intermediate layers are deposited between the base layer and the end layer and are alternately made of TiO2 and Al2O3, such that the intermediate layer covering the base layer is made of TiO2 and the layer in contact with the end layer is made of Al2O3.

[0011] In some embodiments, the substrate is formed by an object made of pure aluminum or an aluminum alloy, and the object includes a support surface. Instruction manual, page 1 / 3, CN 122260760 A

[0012] In some embodiments, the substrate comprises an object on which a coating made of aluminum nitride, aluminum carbide, aluminum oxide or aluminum carbonitride is formed, and the coating comprises a support surface.

[0013] In some embodiments, the thin film dielectric coating comprises four intermediate layers.

[0014] In some embodiments, the thickness of the layers in the thin film dielectric coating (110) is selected to impart interference colors to external parts, which are characterized in CIELAB space in a reflection mode with a standard light source D65, an observation angle of 10° and a measurement geometry of di: 8° as parameters L* = [75; 85], a* = [-45; -35], b* = [5; 15].

[0015] In some specific embodiments, the base layer has a thickness of 1 nm to 10 nm, the intermediate layer has a thickness of 20 nm to 90 nm, and the end layer has a thickness of 55 nm to 65 nm.

[0016] In some specific embodiments, intermediate layers obtained consecutively from the intermediate layer closest to the base layer to the intermediate layer closest to the end layer have thicknesses of 25 nm to 30 nm, 75 nm to 85 nm, 15 nm to 25 nm, and 15 nm to 25 nm, respectively. Brief Description of the Drawings

[0017] Other features and advantages of the invention will become apparent from the following detailed description given by non-limiting examples, and with reference to FIG1, FIG1 schematically shows a cross-sectional view of an external part according to a preferred exemplary embodiment of the invention.

[0018] It should be understood that the drawings are not drawn to scale for clarity. Detailed Description

[0019] The present invention relates to an external part 10 for use in watches, jewelry, or fine jewelry, characterized in that the part comprises a substrate 100 having a support surface 101 made of a material containing at least 50% by mass aluminum.

[0020] FIG1 schematically shows the external part 10 of the present invention, which is particularly suitable for forming a dial of a clock or any other part of a clock, preferably an internal part, such as a scale or hands.

[0021] In this specification, the material of the substrate may be pure aluminum, aluminum alloy, aluminum nitride, aluminum carbide, aluminum oxide, etc.

[0022] The substrate 100 is formed of an object; in one exemplary embodiment of the invention, the object is made of a material containing at least 50% by weight aluminum. Therefore, the support surface 101 is formed of one surface of the object.

[0023] In other exemplary embodiments of the invention, the substrate 100 may comprise an object on which a coating containing at least 50% by weight aluminum is formed. Therefore, the support surface 101 is formed of the surface of the coating.

[0024] Naturally, the type of material containing at least 50% by weight aluminum determines whether the support surface 101 is formed of an object or a coating. For example, if the material is pure aluminum or an aluminum alloy, it may constitute the object of the substrate 100. If the material is aluminum nitride, aluminum carbide, or aluminum carbonitride, it can form a coating deposited by a suitable deposition method, such as physical vapor deposition or chemical vapor deposition. Alternatively, if the material is aluminum oxide, it can form a coating obtained by anodizing in a manner known in the art.

[0025] The external part 10 includes a thin-film dielectric coating 110 on its support surface 101, which is translucent, i.e., transparent at least in the visible light range. These layers in the thin-film dielectric coating 110 are each deposited by an ALD method. Each layer in the thin-film dielectric coating 110 has a thickness of several nanometers to tens of nanometers.This feature allows the support surface 101 of the external part 10 to be protected from chemical and environmental erosion such as humidity, and to be colored in a repeatable and robust manner through precisely selected interference. Therefore, the thickness of the thin-film dielectric coating 110 is uniform and consistent across its entire surface.

[0026] The support surface 101 may have a structure, for example, achieved by machining, such as by hand engraving or machining with a CNC machine tool, by chemical processing or by laser processing. The structure is formed by voids and peaks, the distance between which is, for example, at least 1 µm, and its appearance is advantageously protected by the thin-film dielectric coating 110. Specification 2 / 3 pages 4 CN 122260760 A

[0027] The thin-film dielectric coating 110 is formed of at least two thin dielectric layers, including an end layer 112 and a base layer 111 covering the support surface 101. The base layer 111 is advantageously made of Al2O3, and the end layer 112 is advantageously made of TiO2.

[0028] In particular, the end layer 112 made of TiO2 advantageously ensures chemical protection for external parts.

[0029] In a preferred exemplary embodiment of the invention shown in FIG. 1, the thin-film dielectric coating 110 comprises four intermediate layers 113 deposited between the base layer 111 and the end layer 112. These intermediate layers 113 are alternately made of TiO2 and Al2O3, such that the intermediate layer 113 covering the base layer 111 is made of TiO2, and the layer in contact with the end layer 112 is made of Al2O3.

[0030] In other exemplary embodiments, the thin-film dielectric coating 110 may comprise more or fewer than four intermediate layers 113, provided that the number of intermediate layers is even. In other words, the thin-film dielectric coating 110 may comprise at least two layers.

[0031] Advantageously, the substrate 111 has excellent chemical affinity for the support surface 101 used for its deposition, which ensures excellent adhesion between the substrate 111 and, consequently, the thin-film dielectric coating 110, thereby increasing the deposition rate of the substrate 111.

[0032] The thin-film dielectric coating 110 imparts interference colors to the external part 10, the hue of which depends on the thickness of each layer in the thin-film dielectric coating 110, their arrangement and number, and the material used to form the support surface 101. Therefore, the interference colors produced by the features of the present invention are advantageously very accurate.

[0033] In a preferred exemplary embodiment of the invention, the thickness of the layer in the thin-film dielectric coating (110) is selected to impart interference colors to the external part 10, which are characterized in CIELAB space in a reflection mode with a standard light source D65, an observation angle of 10° and measurement geometry of di: 8° as parameters L* = [75; 85], a* = [-45; -35], b* = [5; 15], and more particularly parameters L* = 79, a* = -39, b* = 8.

[0034] Therefore, in this first variant, the outer part 10 has a light green or turquoise green appearance.

[0035] In this example, each layer in the thin-film dielectric coating (110) has a thickness of 1 nanometer to tens of nanometers, for example, 1 nm to 90 nm. In particular, the base layer 111 has a thickness of 1 nm to 10 nm, the intermediate layer 113 has a thickness of 20 nm to 90 nm, and the end layer 112 has a thickness of 55 nm to 65 nm. More specifically, the intermediate layers 113 obtained sequentially from the intermediate layer 113 closest to the base layer 111 to the intermediate layer 113 closest to the end layer 112 have the following thicknesses: 25 nm to 30 nm, 75 nm to 85 nm, 15 nm to 25 nm, and 15 nm to 25 nm, respectively.

[0036] More generally, it should be noted that the embodiments and applications described above are described by way of non-limiting examples, and other variants may also be considered. Instruction 3 / 3 Page 5 CN 122260760 A Figure 1 Instruction drawing 1 / 1 Page 6 CN 122260760 A Abstract The present invention relates to an external part (10) for use in watches, jewelry or fine jewelry, characterized in that the part comprises a substrate (100), the substrate having a support surface (101) made of a material containing at least 50% by mass aluminium, wherein a translucent thin film dielectric coating (110) is deposited on the support surface, the thin film dielectric coating comprising at least two layers, including an end layer (112) made of TiO2 and a base layer (111) made of Al2O3 covering the support surface (101).

Claims

1. An external part (10) for use in watches, jewelry or fine jewelry, characterized in that The part comprises a substrate (100) having a support surface (101) made of a material containing at least 50% by mass aluminum, on which a translucent thin-film dielectric coating (110) is deposited, the thin-film dielectric coating comprising at least two layers, including an end layer (112) made of TiO2 and a base layer (111) made of Al2O3 covering the support surface (101).

2. The external part (10) according to claim 1, comprising an even number of intermediate layers (113), wherein at least two of the intermediate layers (113) are deposited between a base layer (111) and an end layer (112) and are alternately made of TiO2 and Al2O3, such that the intermediate layer (113) covering the base layer (111) is made of TiO2 and the layer in contact with the end layer (112) is made of Al2O3.

3. The external part (10) according to claim 1 or 2, wherein the substrate (100) is formed by an object made of pure aluminum or an aluminum alloy, and the object includes a support surface (101).

4. The external part (10) according to claim 1 or 2, wherein the substrate (100) comprises an object on which a coating made of aluminum nitride, aluminum carbide, aluminum oxide or aluminum carbonitride is formed, and the coating comprises a support surface (101).

5. The external part (10) according to claim 2, wherein the thin film dielectric coating (110) comprises four intermediate layers (113).

6. The external part (10) according to claim 5, wherein the thickness of the layer in the thin film dielectric coating (110) is selected to impart interference colors to the external part (10), which are characterized in CIELAB space in a reflection mode with a standard light source D65, an observation angle of 10° and a measurement geometry of di: 8° as parameters L* = [75; 85], a* = [-45; -35], b* = [5; 15].

7. The external part (10) according to claim 6, wherein the base layer (111) has a thickness of 1 nm to 10 nm, the intermediate layer (113) has a thickness of 20 nm to 90 nm, and the end layer (112) has a thickness of 55 nm to 65 nm.

8. The external part (10) according to claim 7, wherein the intermediate layers (113) obtained continuously from the intermediate layer (113) closest to the base layer (111) to the intermediate layer (113) closest to the end layer (112) have thicknesses of 25 nm to 30 nm, 75 nm to 85 nm, 15 nm to 25 nm and 15 nm to 25 nm, respectively.

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